Bulletin of The Astronomical Society of India, 2000
Of the 31 known rapidly oscillating Ap (roAp) stars, 28 are in the southern sky and majority of t... more Of the 31 known rapidly oscillating Ap (roAp) stars, 28 are in the southern sky and majority of them were discovered at SAAO indicating that a systematic survey also is needed in the northern sky. Therefore, a project has been initiated at the Uttar Pradesh State Observatory in Naini Tal with the objective to find and study new roAp stars in the northern sky. The test observing campaigns were made during 1997 and 1998 from UPSO at Naini Tal. A brief report of these efforts is presented here. The initial results were encouraging and qualified the site, the telescope and the instrument as the right combination needed for the success of the project. Though these preliminary observations did not yield new roAp stars, they did lead to the discovery of delta Scuti pulsations in two chemically peculiar stars, HD 13079 and HD 13038.
Bulletin of The Astronomical Society of India, 2000
Of the 31 known rapidly oscillating Ap (roAp) stars, 28 are in the southern sky and majority of t... more Of the 31 known rapidly oscillating Ap (roAp) stars, 28 are in the southern sky and majority of them were discovered at SAAO indicating that a systematic survey also is needed in the northern sky. Therefore, a project has been initiated at the Uttar Pradesh State Observatory in Naini Tal with the objective to find and study new roAp stars in the northern sky. The test observing campaigns were made during 1997 and 1998 from UPSO at Naini Tal. A brief report of these efforts is presented here. The initial results were encouraging and qualified the site, the telescope and the instrument as the right combination needed for the success of the project. Though these preliminary observations did not yield new roAp stars, they did lead to the discovery of delta Scuti pulsations in two chemically peculiar stars, HD 13079 and HD 13038.
Monthly Notices of The Royal Astronomical Society, 1999
Pulsation in cool main-sequence Am stars is a rare phenomenon observed in a few marginal Am stars... more Pulsation in cool main-sequence Am stars is a rare phenomenon observed in a few marginal Am stars and only one classical Am star. The chemically peculiar star HD 13079 is shown to be pulsating with a 78-min period and a peak-to-peak B amplitude of 0.02 mag. The Hipparcos parallax, uvbyb photometry and pulsations together suggest that HD 13079 is an Am star near the zero-age main sequence, and that it is a fundamental-mode pulsator on the red edge of the instability strip.
Monthly Notices of The Royal Astronomical Society, 1999
Pulsation in cool main-sequence Am stars is a rare phenomenon observed in a few marginal Am stars... more Pulsation in cool main-sequence Am stars is a rare phenomenon observed in a few marginal Am stars and only one classical Am star. The chemically peculiar star HD 13079 is shown to be pulsating with a 78-min period and a peak-to-peak B amplitude of 0.02 mag. The Hipparcos parallax, uvbyb photometry and pulsations together suggest that HD 13079 is an Am star near the zero-age main sequence, and that it is a fundamental-mode pulsator on the red edge of the instability strip.
A semi-purified extract of low-altitude Podophyllum hexandrum (REC-2001) containing a relatively ... more A semi-purified extract of low-altitude Podophyllum hexandrum (REC-2001) containing a relatively low content of podophyllotoxin (3.25 %) exhibited potent antioxidant ability in lipid media (at 1000 microg/mLagainst 0.25 kGy) and significant (p < 0.05) hydroxyl ion scavenging potential (78.83 % at 500 microg/mL). In vitro investigations revealed the ability of REC-2001 to significantly (p…
The development of radioprotective agents has been the subject of intense research in view of the... more The development of radioprotective agents has been the subject of intense research in view of their potential for use within a radiation environment, such as space exploration, radiotherapy and even nuclear war. However, no ideal, safe synthetic radioprotectors are available to date, so the search for alternative sources, including plants, has been on going for several decades. In Ayurveda, the traditional Indian system of medicine, several plants have been used to treat free radical-mediated ailments and, therefore, it is logical to expect that such plants may also render some protection against radiation damage. A systematic screening approach can provide leads to identifying potential new candidate drugs from plant sources, for mitigation of radiation injury. This article reviews some of the most promising plants, and their bioactive principles, that are widely used in traditional systems of medicine, and which have rendered significant radioprotection in both in vitro and in vivo model systems. Plants and their constituents with pharmacological activities that may be relevant to amelioration of radiation-mediated damage, including antiemetic, antiinflammatory, antioxidant, cell proliferative, wound healing and haemopoietic stimulatories are also discussed.
A semi-purified extract of low-altitude Podophyllum hexandrum (REC-2001) containing a relatively ... more A semi-purified extract of low-altitude Podophyllum hexandrum (REC-2001) containing a relatively low content of podophyllotoxin (3.25 %) exhibited potent antioxidant ability in lipid media (at 1000 microg/mLagainst 0.25 kGy) and significant (p < 0.05) hydroxyl ion scavenging potential (78.83 % at 500 microg/mL). In vitro investigations revealed the ability of REC-2001 to significantly (p…
To evaluate radiation protection offered by the extract of Podophyllum hexandrum, expression of v... more To evaluate radiation protection offered by the extract of Podophyllum hexandrum, expression of various cytoprotective proteins was studied using liver of Swiss albino Strain 'A' male mouse by immunoblotting. Induction of heat-shock factor-1 (HSF-1), led to up-regulation of heat-shock protein-70 (HSP-70) upon P. hexandrum (200 mg/kg b. wt.; i.p. 50% ethanolic extract) treatment 2 h before irradiation (10 Gy) as compared to sham-irradiated control. Translocation of free nuclear factor kappa B (NFB) from cytoplasm to nucleus was found to be inhibited upon P. hexandrum treatment. An increase in Bcl-2, proliferating cell nuclear antigen (PCNA) along with a decrease in p53, caspase-3, apoptosis inducing factor (AIF) expression was observed in the mice treated with P. hexandrum. The present study indicated that P. hexandrum extract provides protection from radiation by modulation of expression of the proteins associated with apoptosis.
The development of radioprotective agents has been the subject of intense research in view of the... more The development of radioprotective agents has been the subject of intense research in view of their potential for use within a radiation environment, such as space exploration, radiotherapy and even nuclear war. However, no ideal, safe synthetic radioprotectors are available to date, so the search for alternative sources, including plants, has been on going for several decades. In Ayurveda, the traditional Indian system of medicine, several plants have been used to treat free radical-mediated ailments and, therefore, it is logical to expect that such plants may also render some protection against radiation damage. A systematic screening approach can provide leads to identifying potential new candidate drugs from plant sources, for mitigation of radiation injury. This article reviews some of the most promising plants, and their bioactive principles, that are widely used in traditional systems of medicine, and which have rendered significant radioprotection in both in vitro and in vivo model systems. Plants and their constituents with pharmacological activities that may be relevant to amelioration of radiation-mediated damage, including antiemetic, antiinflammatory, antioxidant, cell proliferative, wound healing and haemopoietic stimulatories are also discussed.
Whole extract of rhizomes of Podophyllum hexandrum has been reported earlier by our group to rend... more Whole extract of rhizomes of Podophyllum hexandrum has been reported earlier by our group to render whole-body radioprotection. High-altitude P. hexandrum (HAPH) was therefore fractionated using solvents of varying polarity (non-polar to polar) and the different fractions were designated as, n-hexane (HE), chloroform (CE), alcohol (AE), hydro-alcohol (HA) and water (WE). The total polyphenolic content (mg% of quercetin) was determined spectrophotometrically, while. The major constituents present in each fraction were identified and characterized using LC-APCI/MS/MS. In vitro screening of the individual fractions, rich in polyphenols and lignans, revealed several bioactivities of direct relevance to radioprotection e.g. metal-chelation activity, antioxidant activity, DNA protection, inhibition of radiation (250 Gy) and iron/ascorbate-induced lipid peroxidation (LPO). CE exhibited maximum protection to plasmid (pBR322) DNA in the plasmid relaxation assay (68.09% of SC form retention). It also showed maximal metal chelation activity (41.59%), evaluated using 2,2′-bipyridyl assay, followed by AE (31.25%), which exhibited maximum antioxidant potential (lowest absorption unit value: 0.0389± 0.00717) in the reducing power assay. AE also maximally inhibited iron/ascorbate-induced and radiation-induced LPO (99.76 and 92.249%, respectively, at 2000 μg/ml) in mouse liver homogenate. Under conditions of combined stress (radiation (250 Gy) + iron/ascorbate), at a concentration of 2000 μg/ml, HA exhibited higher percentage of inhibition (93.05%) of LPO activity. HA was found to be effective in significantly (p < 0.05) lowering LPO activity over a wide range of concentrations as compared to AE. The present comparative study indicated that alcoholic (AE) and hydro-alcoholic (HA) fractions are the most promising fractions, which can effectively tackle radiation-induced oxidative stress.
To evaluate radiation protection offered by the extract of Podophyllum hexandrum, expression of v... more To evaluate radiation protection offered by the extract of Podophyllum hexandrum, expression of various cytoprotective proteins was studied using liver of Swiss albino Strain 'A' male mouse by immunoblotting. Induction of heat-shock factor-1 (HSF-1), led to up-regulation of heat-shock protein-70 (HSP-70) upon P. hexandrum (200 mg/kg b. wt.; i.p. 50% ethanolic extract) treatment 2 h before irradiation (10 Gy) as compared to sham-irradiated control. Translocation of free nuclear factor kappa B (NFB) from cytoplasm to nucleus was found to be inhibited upon P. hexandrum treatment. An increase in Bcl-2, proliferating cell nuclear antigen (PCNA) along with a decrease in p53, caspase-3, apoptosis inducing factor (AIF) expression was observed in the mice treated with P. hexandrum. The present study indicated that P. hexandrum extract provides protection from radiation by modulation of expression of the proteins associated with apoptosis.
The aryl tetralin lignans are synthesized by Podophyllum sps. and are in great demand worldwide d... more The aryl tetralin lignans are synthesized by Podophyllum sps. and are in great demand worldwide due to their use in synthesis of topoisomerase inhibitors. However, the sustained production of these aryl tetralin lignans requires large-scale harvesting from the natural environments, which has resulted in the plant-endangered status. In view of the difficulties in their total chemical synthesis, cultivation and failure of metabolic engineering approaches, there is a need to search for alternative sources of production of aryl tetralin lignans. We unequivocally established the methodology for isolation, identification, and characterization of a novel fungal endophyte (Trametes hirsuta) that produces aryl tetralin lignans consistently as shown by HPLC, LC-MS, LC/MS-MS and 1 H NMR. The lignans produced by the microorganism are biologically active, and exhibit potent antioxidant, anticancer and radioprotective properties. This strategy promises to improve the production of these therapeutically important compounds at lower costs.
Whole extract of rhizomes of Podophyllum hexandrum has been reported earlier by our group to rend... more Whole extract of rhizomes of Podophyllum hexandrum has been reported earlier by our group to render whole-body radioprotection. High-altitude P. hexandrum (HAPH) was therefore fractionated using solvents of varying polarity (non-polar to polar) and the different fractions were designated as, n-hexane (HE), chloroform (CE), alcohol (AE), hydro-alcohol (HA) and water (WE). The total polyphenolic content (mg% of quercetin) was determined spectrophotometrically, while. The major constituents present in each fraction were identified and characterized using LC-APCI/MS/MS. In vitro screening of the individual fractions, rich in polyphenols and lignans, revealed several bioactivities of direct relevance to radioprotection e.g. metal-chelation activity, antioxidant activity, DNA protection, inhibition of radiation (250 Gy) and iron/ascorbate-induced lipid peroxidation (LPO). CE exhibited maximum protection to plasmid (pBR322) DNA in the plasmid relaxation assay (68.09% of SC form retention). It also showed maximal metal chelation activity (41.59%), evaluated using 2,2′-bipyridyl assay, followed by AE (31.25%), which exhibited maximum antioxidant potential (lowest absorption unit value: 0.0389± 0.00717) in the reducing power assay. AE also maximally inhibited iron/ascorbate-induced and radiation-induced LPO (99.76 and 92.249%, respectively, at 2000 μg/ml) in mouse liver homogenate. Under conditions of combined stress (radiation (250 Gy) + iron/ascorbate), at a concentration of 2000 μg/ml, HA exhibited higher percentage of inhibition (93.05%) of LPO activity. HA was found to be effective in significantly (p < 0.05) lowering LPO activity over a wide range of concentrations as compared to AE. The present comparative study indicated that alcoholic (AE) and hydro-alcoholic (HA) fractions are the most promising fractions, which can effectively tackle radiation-induced oxidative stress.
The aryl tetralin lignans are synthesized by Podophyllum sps. and are in great demand worldwide d... more The aryl tetralin lignans are synthesized by Podophyllum sps. and are in great demand worldwide due to their use in synthesis of topoisomerase inhibitors. However, the sustained production of these aryl tetralin lignans requires large-scale harvesting from the natural environments, which has resulted in the plant-endangered status. In view of the difficulties in their total chemical synthesis, cultivation and failure of metabolic engineering approaches, there is a need to search for alternative sources of production of aryl tetralin lignans. We unequivocally established the methodology for isolation, identification, and characterization of a novel fungal endophyte (Trametes hirsuta) that produces aryl tetralin lignans consistently as shown by HPLC, LC-MS, LC/MS-MS and 1 H NMR. The lignans produced by the microorganism are biologically active, and exhibit potent antioxidant, anticancer and radioprotective properties. This strategy promises to improve the production of these therapeutically important compounds at lower costs.
Plants are an abundant source of medicinal compounds, some of which are useful in combating free ... more Plants are an abundant source of medicinal compounds, some of which are useful in combating free radical-mediated oxidative stress. In the present study, initially two fractions designated REC-1001 (flavonoid-rich fraction) and REC-1002 (flavonoid-poor fraction) of Hippophae rhamnoides were screened on the basis of their reducing power in the aqueous phase. REC-1001 was selected for further study, since it exhibited 27.38 times higher antioxidant activity than REC-1002. REC-1001 also showed significant (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; .05) membrane protection potential at 50 microg/mL, which was attributed to its ability to scavenge peroxyl radicals (64.82 +/- 1.25% scavenging within 1,440 min). A significant (P…
Podophyllum hexandrum Royale (Himalayan mayapple), a high-altitude Himalayan plant, has been show... more Podophyllum hexandrum Royale (Himalayan mayapple), a high-altitude Himalayan plant, has been shown to provide over 80 % whole-body radioprotection in mice. To investigate the radioprotective potential of P. hexandrum at the molecular level, expression patterns of various proteins associated with apoptosis were studied in the spleen of male Swiss albino strain A mice by immunoblotting. Treatment with P. hexandrum [200 mg/ kg of body weight; an ethanolic 50 % (w/v) extract delivered intraperitoneally] 2 h before irradiation resulted in MAPKAP (mitogen-activated protein kinase-activated protein) kinase-2 activation along with HSF-1 (heat-shock transcription factor-1), leading to upregulation of HSP-70 (heat-shock protein-70) as compared with sham-irradiated (10 Gy) mice. Strong inhibition of AIF (apoptosis-inducing factor) expression was observed in the mice treated with P. hexandrum 2 h before irradiation as compared with the shamirradiated group. Inhibition in the translocation of free NF-κB (nuclear factor κB) from cytoplasm to nucleus was observed upon P. hexandrum pretreatment 2 h before irradiation when compared with radiationtreated mice. P. hexandrum pre-treatment (2 h before irradiation) resulted in inhibition of NF-κB translocation, and the expression of tumour suppressor protein p53 was observed to be down-regulated as compared with sham-irradiated control. An increase in the expression of proteins responsible for cell proliferation [Bcl-2 (B-cell chronic lymphocytic lymphoma 2), Ras-GAP (Ras-GTPase-activating protein) and PCNA (proliferating cell nuclear antigen)] was observed in the P. hexandrum-pretreated irradiated mice as compared with sham-irradiated controls. Caspase 3 activation resulted PARP [poly(ADP-ribose) DNA polymerase] cleavage, and DNA degradation was strongly inhibited in the mice treated with P. hexandrm (+/− irradiation) as compared with the mice treated with radiation (+/− heat shock). The present study thus clearly demonstrated that P. hexandrum extract provides protection from γ -radiation by the modu-lation of expression of proteins associated with cell death.
Plants are an abundant source of medicinal compounds, some of which are useful in combating free ... more Plants are an abundant source of medicinal compounds, some of which are useful in combating free radical-mediated oxidative stress. In the present study, initially two fractions designated REC-1001 (flavonoid-rich fraction) and REC-1002 (flavonoid-poor fraction) of Hippophae rhamnoides were screened on the basis of their reducing power in the aqueous phase. REC-1001 was selected for further study, since it exhibited 27.38 times higher antioxidant activity than REC-1002. REC-1001 also showed significant (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; .05) membrane protection potential at 50 microg/mL, which was attributed to its ability to scavenge peroxyl radicals (64.82 +/- 1.25% scavenging within 1,440 min). A significant (P…
The present study reports the radioprotective properties of a hydro-alcoholic rhizome extract of ... more The present study reports the radioprotective properties of a hydro-alcoholic rhizome extract of Rhodiola imbricata (code named REC-7004), a plant native to the high-altitude Himalayas. The radioprotective effect, along with its relevant superoxide ion scavenging, metal chelation, antioxidant, anti-lipid peroxidation and anti-hemolytic activities was evaluated under both in vitro and in vivo conditions. Chemical analysis showed the presence of high content of polyphenolics (0.971 ± 0.01 mg% of quercetin). Absorption spectra analysis revealed constituents that absorb in the range of 220–290 nm, while high-performance liquid chromatography (HPLC) analysis confirmed the presence of four major peaks with retention times of 4.780, 5.767, 6.397 and 7.577 min. REC-7004 was found to lower lipid oxidation significantly (p < 0.05) at concentrations viz., 8 and 80 μg/ml respectively as compared to reduced glutathione, although the optimally protective dose was 80 μg/ml, which showed 59.5% inhibition of induction of linoleic acid degradation within first 24 h. The metal chelation activity of REC-7004 was found to increase concomitantly from 1 to 50 μg/ml. REC-7004 (10–50 μg/ml) exhibited significant metal chelation activity (p < 0.05), as compared to control, and maximum percentage inhibition (30%) of formation of iron-2,2′-bi-pyridyl complex was observed at 50 μg/ml, which correlated well with quercetin (34.9%), taken as standard. The reducing power of REC-7004 increased in a dose-dependent manner. The absorption unit value of REC-7004 was significantly lower (0.0183± 0.0033) as compared to butylated hydroxy toluene, a standard antioxidant (0.230± 0.091), confirming its high reducing ability. Superoxide ion scavenging ability of REC-7004 exhibited a dose-dependent increase (1–100 μg/ml) and was significantly higher (p < 0.05) than that of quercetin at lower concentrations (1–10 μg/ml), while at 100 μg/ml, both quercetin and REC-7004 scavenged over 90% superoxide anions. MTT assay in U87 cell line revealed an increase in percent survival of cells at doses between 25 and 125 μg/ml in case of drug + radiation group. In vivo evaluation of radio-protective efficacy in mice revealed that intraperitoneal administration of REC-7004 (maximally effective dose: 400 mg/kg b.w.) 30 min prior to lethal (10 Gy) total-body γ-irradiation rendered 83.3% survival. The ability of REC-7004 to inhibit lipid peroxidation induced by iron/ascorbate, radiation (250 Gy) and their combination [i.e., iron/ascorbate and radiation (250 Gy)], was also investigated and was found to decrease in a dose-dependent manner (0.05–2 mg/ml). The maximum percent inhibition of formation of MDA-TBA complex at 2 mg/ml in case of iron/ascorbate, radiation (250 Gy) and both i.e., iron/ascorbate with radiation (250 Gy) was 53.78, 63.07, and 51.76% respectively and were found to be comparable to that of quercetin. REC-7004 (1 μg/ml) also exhibited significant anti-hemolytic capacity by preventing radiation-induced membrane degeneration of human erythrocytes. In conclusion, Rhodiola renders in vitro and in vivo radioprotection via multifarious mechanisms that act in a synergistic manner.
Bulletin of The Astronomical Society of India, 2000
Of the 31 known rapidly oscillating Ap (roAp) stars, 28 are in the southern sky and majority of t... more Of the 31 known rapidly oscillating Ap (roAp) stars, 28 are in the southern sky and majority of them were discovered at SAAO indicating that a systematic survey also is needed in the northern sky. Therefore, a project has been initiated at the Uttar Pradesh State Observatory in Naini Tal with the objective to find and study new roAp stars in the northern sky. The test observing campaigns were made during 1997 and 1998 from UPSO at Naini Tal. A brief report of these efforts is presented here. The initial results were encouraging and qualified the site, the telescope and the instrument as the right combination needed for the success of the project. Though these preliminary observations did not yield new roAp stars, they did lead to the discovery of delta Scuti pulsations in two chemically peculiar stars, HD 13079 and HD 13038.
Bulletin of The Astronomical Society of India, 2000
Of the 31 known rapidly oscillating Ap (roAp) stars, 28 are in the southern sky and majority of t... more Of the 31 known rapidly oscillating Ap (roAp) stars, 28 are in the southern sky and majority of them were discovered at SAAO indicating that a systematic survey also is needed in the northern sky. Therefore, a project has been initiated at the Uttar Pradesh State Observatory in Naini Tal with the objective to find and study new roAp stars in the northern sky. The test observing campaigns were made during 1997 and 1998 from UPSO at Naini Tal. A brief report of these efforts is presented here. The initial results were encouraging and qualified the site, the telescope and the instrument as the right combination needed for the success of the project. Though these preliminary observations did not yield new roAp stars, they did lead to the discovery of delta Scuti pulsations in two chemically peculiar stars, HD 13079 and HD 13038.
Monthly Notices of The Royal Astronomical Society, 1999
Pulsation in cool main-sequence Am stars is a rare phenomenon observed in a few marginal Am stars... more Pulsation in cool main-sequence Am stars is a rare phenomenon observed in a few marginal Am stars and only one classical Am star. The chemically peculiar star HD 13079 is shown to be pulsating with a 78-min period and a peak-to-peak B amplitude of 0.02 mag. The Hipparcos parallax, uvbyb photometry and pulsations together suggest that HD 13079 is an Am star near the zero-age main sequence, and that it is a fundamental-mode pulsator on the red edge of the instability strip.
Monthly Notices of The Royal Astronomical Society, 1999
Pulsation in cool main-sequence Am stars is a rare phenomenon observed in a few marginal Am stars... more Pulsation in cool main-sequence Am stars is a rare phenomenon observed in a few marginal Am stars and only one classical Am star. The chemically peculiar star HD 13079 is shown to be pulsating with a 78-min period and a peak-to-peak B amplitude of 0.02 mag. The Hipparcos parallax, uvbyb photometry and pulsations together suggest that HD 13079 is an Am star near the zero-age main sequence, and that it is a fundamental-mode pulsator on the red edge of the instability strip.
A semi-purified extract of low-altitude Podophyllum hexandrum (REC-2001) containing a relatively ... more A semi-purified extract of low-altitude Podophyllum hexandrum (REC-2001) containing a relatively low content of podophyllotoxin (3.25 %) exhibited potent antioxidant ability in lipid media (at 1000 microg/mLagainst 0.25 kGy) and significant (p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.05) hydroxyl ion scavenging potential (78.83 % at 500 microg/mL). In vitro investigations revealed the ability of REC-2001 to significantly (p…
The development of radioprotective agents has been the subject of intense research in view of the... more The development of radioprotective agents has been the subject of intense research in view of their potential for use within a radiation environment, such as space exploration, radiotherapy and even nuclear war. However, no ideal, safe synthetic radioprotectors are available to date, so the search for alternative sources, including plants, has been on going for several decades. In Ayurveda, the traditional Indian system of medicine, several plants have been used to treat free radical-mediated ailments and, therefore, it is logical to expect that such plants may also render some protection against radiation damage. A systematic screening approach can provide leads to identifying potential new candidate drugs from plant sources, for mitigation of radiation injury. This article reviews some of the most promising plants, and their bioactive principles, that are widely used in traditional systems of medicine, and which have rendered significant radioprotection in both in vitro and in vivo model systems. Plants and their constituents with pharmacological activities that may be relevant to amelioration of radiation-mediated damage, including antiemetic, antiinflammatory, antioxidant, cell proliferative, wound healing and haemopoietic stimulatories are also discussed.
A semi-purified extract of low-altitude Podophyllum hexandrum (REC-2001) containing a relatively ... more A semi-purified extract of low-altitude Podophyllum hexandrum (REC-2001) containing a relatively low content of podophyllotoxin (3.25 %) exhibited potent antioxidant ability in lipid media (at 1000 microg/mLagainst 0.25 kGy) and significant (p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.05) hydroxyl ion scavenging potential (78.83 % at 500 microg/mL). In vitro investigations revealed the ability of REC-2001 to significantly (p…
To evaluate radiation protection offered by the extract of Podophyllum hexandrum, expression of v... more To evaluate radiation protection offered by the extract of Podophyllum hexandrum, expression of various cytoprotective proteins was studied using liver of Swiss albino Strain 'A' male mouse by immunoblotting. Induction of heat-shock factor-1 (HSF-1), led to up-regulation of heat-shock protein-70 (HSP-70) upon P. hexandrum (200 mg/kg b. wt.; i.p. 50% ethanolic extract) treatment 2 h before irradiation (10 Gy) as compared to sham-irradiated control. Translocation of free nuclear factor kappa B (NFB) from cytoplasm to nucleus was found to be inhibited upon P. hexandrum treatment. An increase in Bcl-2, proliferating cell nuclear antigen (PCNA) along with a decrease in p53, caspase-3, apoptosis inducing factor (AIF) expression was observed in the mice treated with P. hexandrum. The present study indicated that P. hexandrum extract provides protection from radiation by modulation of expression of the proteins associated with apoptosis.
The development of radioprotective agents has been the subject of intense research in view of the... more The development of radioprotective agents has been the subject of intense research in view of their potential for use within a radiation environment, such as space exploration, radiotherapy and even nuclear war. However, no ideal, safe synthetic radioprotectors are available to date, so the search for alternative sources, including plants, has been on going for several decades. In Ayurveda, the traditional Indian system of medicine, several plants have been used to treat free radical-mediated ailments and, therefore, it is logical to expect that such plants may also render some protection against radiation damage. A systematic screening approach can provide leads to identifying potential new candidate drugs from plant sources, for mitigation of radiation injury. This article reviews some of the most promising plants, and their bioactive principles, that are widely used in traditional systems of medicine, and which have rendered significant radioprotection in both in vitro and in vivo model systems. Plants and their constituents with pharmacological activities that may be relevant to amelioration of radiation-mediated damage, including antiemetic, antiinflammatory, antioxidant, cell proliferative, wound healing and haemopoietic stimulatories are also discussed.
Whole extract of rhizomes of Podophyllum hexandrum has been reported earlier by our group to rend... more Whole extract of rhizomes of Podophyllum hexandrum has been reported earlier by our group to render whole-body radioprotection. High-altitude P. hexandrum (HAPH) was therefore fractionated using solvents of varying polarity (non-polar to polar) and the different fractions were designated as, n-hexane (HE), chloroform (CE), alcohol (AE), hydro-alcohol (HA) and water (WE). The total polyphenolic content (mg% of quercetin) was determined spectrophotometrically, while. The major constituents present in each fraction were identified and characterized using LC-APCI/MS/MS. In vitro screening of the individual fractions, rich in polyphenols and lignans, revealed several bioactivities of direct relevance to radioprotection e.g. metal-chelation activity, antioxidant activity, DNA protection, inhibition of radiation (250 Gy) and iron/ascorbate-induced lipid peroxidation (LPO). CE exhibited maximum protection to plasmid (pBR322) DNA in the plasmid relaxation assay (68.09% of SC form retention). It also showed maximal metal chelation activity (41.59%), evaluated using 2,2′-bipyridyl assay, followed by AE (31.25%), which exhibited maximum antioxidant potential (lowest absorption unit value: 0.0389± 0.00717) in the reducing power assay. AE also maximally inhibited iron/ascorbate-induced and radiation-induced LPO (99.76 and 92.249%, respectively, at 2000 μg/ml) in mouse liver homogenate. Under conditions of combined stress (radiation (250 Gy) + iron/ascorbate), at a concentration of 2000 μg/ml, HA exhibited higher percentage of inhibition (93.05%) of LPO activity. HA was found to be effective in significantly (p < 0.05) lowering LPO activity over a wide range of concentrations as compared to AE. The present comparative study indicated that alcoholic (AE) and hydro-alcoholic (HA) fractions are the most promising fractions, which can effectively tackle radiation-induced oxidative stress.
To evaluate radiation protection offered by the extract of Podophyllum hexandrum, expression of v... more To evaluate radiation protection offered by the extract of Podophyllum hexandrum, expression of various cytoprotective proteins was studied using liver of Swiss albino Strain 'A' male mouse by immunoblotting. Induction of heat-shock factor-1 (HSF-1), led to up-regulation of heat-shock protein-70 (HSP-70) upon P. hexandrum (200 mg/kg b. wt.; i.p. 50% ethanolic extract) treatment 2 h before irradiation (10 Gy) as compared to sham-irradiated control. Translocation of free nuclear factor kappa B (NFB) from cytoplasm to nucleus was found to be inhibited upon P. hexandrum treatment. An increase in Bcl-2, proliferating cell nuclear antigen (PCNA) along with a decrease in p53, caspase-3, apoptosis inducing factor (AIF) expression was observed in the mice treated with P. hexandrum. The present study indicated that P. hexandrum extract provides protection from radiation by modulation of expression of the proteins associated with apoptosis.
The aryl tetralin lignans are synthesized by Podophyllum sps. and are in great demand worldwide d... more The aryl tetralin lignans are synthesized by Podophyllum sps. and are in great demand worldwide due to their use in synthesis of topoisomerase inhibitors. However, the sustained production of these aryl tetralin lignans requires large-scale harvesting from the natural environments, which has resulted in the plant-endangered status. In view of the difficulties in their total chemical synthesis, cultivation and failure of metabolic engineering approaches, there is a need to search for alternative sources of production of aryl tetralin lignans. We unequivocally established the methodology for isolation, identification, and characterization of a novel fungal endophyte (Trametes hirsuta) that produces aryl tetralin lignans consistently as shown by HPLC, LC-MS, LC/MS-MS and 1 H NMR. The lignans produced by the microorganism are biologically active, and exhibit potent antioxidant, anticancer and radioprotective properties. This strategy promises to improve the production of these therapeutically important compounds at lower costs.
Whole extract of rhizomes of Podophyllum hexandrum has been reported earlier by our group to rend... more Whole extract of rhizomes of Podophyllum hexandrum has been reported earlier by our group to render whole-body radioprotection. High-altitude P. hexandrum (HAPH) was therefore fractionated using solvents of varying polarity (non-polar to polar) and the different fractions were designated as, n-hexane (HE), chloroform (CE), alcohol (AE), hydro-alcohol (HA) and water (WE). The total polyphenolic content (mg% of quercetin) was determined spectrophotometrically, while. The major constituents present in each fraction were identified and characterized using LC-APCI/MS/MS. In vitro screening of the individual fractions, rich in polyphenols and lignans, revealed several bioactivities of direct relevance to radioprotection e.g. metal-chelation activity, antioxidant activity, DNA protection, inhibition of radiation (250 Gy) and iron/ascorbate-induced lipid peroxidation (LPO). CE exhibited maximum protection to plasmid (pBR322) DNA in the plasmid relaxation assay (68.09% of SC form retention). It also showed maximal metal chelation activity (41.59%), evaluated using 2,2′-bipyridyl assay, followed by AE (31.25%), which exhibited maximum antioxidant potential (lowest absorption unit value: 0.0389± 0.00717) in the reducing power assay. AE also maximally inhibited iron/ascorbate-induced and radiation-induced LPO (99.76 and 92.249%, respectively, at 2000 μg/ml) in mouse liver homogenate. Under conditions of combined stress (radiation (250 Gy) + iron/ascorbate), at a concentration of 2000 μg/ml, HA exhibited higher percentage of inhibition (93.05%) of LPO activity. HA was found to be effective in significantly (p < 0.05) lowering LPO activity over a wide range of concentrations as compared to AE. The present comparative study indicated that alcoholic (AE) and hydro-alcoholic (HA) fractions are the most promising fractions, which can effectively tackle radiation-induced oxidative stress.
The aryl tetralin lignans are synthesized by Podophyllum sps. and are in great demand worldwide d... more The aryl tetralin lignans are synthesized by Podophyllum sps. and are in great demand worldwide due to their use in synthesis of topoisomerase inhibitors. However, the sustained production of these aryl tetralin lignans requires large-scale harvesting from the natural environments, which has resulted in the plant-endangered status. In view of the difficulties in their total chemical synthesis, cultivation and failure of metabolic engineering approaches, there is a need to search for alternative sources of production of aryl tetralin lignans. We unequivocally established the methodology for isolation, identification, and characterization of a novel fungal endophyte (Trametes hirsuta) that produces aryl tetralin lignans consistently as shown by HPLC, LC-MS, LC/MS-MS and 1 H NMR. The lignans produced by the microorganism are biologically active, and exhibit potent antioxidant, anticancer and radioprotective properties. This strategy promises to improve the production of these therapeutically important compounds at lower costs.
Plants are an abundant source of medicinal compounds, some of which are useful in combating free ... more Plants are an abundant source of medicinal compounds, some of which are useful in combating free radical-mediated oxidative stress. In the present study, initially two fractions designated REC-1001 (flavonoid-rich fraction) and REC-1002 (flavonoid-poor fraction) of Hippophae rhamnoides were screened on the basis of their reducing power in the aqueous phase. REC-1001 was selected for further study, since it exhibited 27.38 times higher antioxidant activity than REC-1002. REC-1001 also showed significant (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; .05) membrane protection potential at 50 microg/mL, which was attributed to its ability to scavenge peroxyl radicals (64.82 +/- 1.25% scavenging within 1,440 min). A significant (P…
Podophyllum hexandrum Royale (Himalayan mayapple), a high-altitude Himalayan plant, has been show... more Podophyllum hexandrum Royale (Himalayan mayapple), a high-altitude Himalayan plant, has been shown to provide over 80 % whole-body radioprotection in mice. To investigate the radioprotective potential of P. hexandrum at the molecular level, expression patterns of various proteins associated with apoptosis were studied in the spleen of male Swiss albino strain A mice by immunoblotting. Treatment with P. hexandrum [200 mg/ kg of body weight; an ethanolic 50 % (w/v) extract delivered intraperitoneally] 2 h before irradiation resulted in MAPKAP (mitogen-activated protein kinase-activated protein) kinase-2 activation along with HSF-1 (heat-shock transcription factor-1), leading to upregulation of HSP-70 (heat-shock protein-70) as compared with sham-irradiated (10 Gy) mice. Strong inhibition of AIF (apoptosis-inducing factor) expression was observed in the mice treated with P. hexandrum 2 h before irradiation as compared with the shamirradiated group. Inhibition in the translocation of free NF-κB (nuclear factor κB) from cytoplasm to nucleus was observed upon P. hexandrum pretreatment 2 h before irradiation when compared with radiationtreated mice. P. hexandrum pre-treatment (2 h before irradiation) resulted in inhibition of NF-κB translocation, and the expression of tumour suppressor protein p53 was observed to be down-regulated as compared with sham-irradiated control. An increase in the expression of proteins responsible for cell proliferation [Bcl-2 (B-cell chronic lymphocytic lymphoma 2), Ras-GAP (Ras-GTPase-activating protein) and PCNA (proliferating cell nuclear antigen)] was observed in the P. hexandrum-pretreated irradiated mice as compared with sham-irradiated controls. Caspase 3 activation resulted PARP [poly(ADP-ribose) DNA polymerase] cleavage, and DNA degradation was strongly inhibited in the mice treated with P. hexandrm (+/− irradiation) as compared with the mice treated with radiation (+/− heat shock). The present study thus clearly demonstrated that P. hexandrum extract provides protection from γ -radiation by the modu-lation of expression of proteins associated with cell death.
Plants are an abundant source of medicinal compounds, some of which are useful in combating free ... more Plants are an abundant source of medicinal compounds, some of which are useful in combating free radical-mediated oxidative stress. In the present study, initially two fractions designated REC-1001 (flavonoid-rich fraction) and REC-1002 (flavonoid-poor fraction) of Hippophae rhamnoides were screened on the basis of their reducing power in the aqueous phase. REC-1001 was selected for further study, since it exhibited 27.38 times higher antioxidant activity than REC-1002. REC-1001 also showed significant (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; .05) membrane protection potential at 50 microg/mL, which was attributed to its ability to scavenge peroxyl radicals (64.82 +/- 1.25% scavenging within 1,440 min). A significant (P…
The present study reports the radioprotective properties of a hydro-alcoholic rhizome extract of ... more The present study reports the radioprotective properties of a hydro-alcoholic rhizome extract of Rhodiola imbricata (code named REC-7004), a plant native to the high-altitude Himalayas. The radioprotective effect, along with its relevant superoxide ion scavenging, metal chelation, antioxidant, anti-lipid peroxidation and anti-hemolytic activities was evaluated under both in vitro and in vivo conditions. Chemical analysis showed the presence of high content of polyphenolics (0.971 ± 0.01 mg% of quercetin). Absorption spectra analysis revealed constituents that absorb in the range of 220–290 nm, while high-performance liquid chromatography (HPLC) analysis confirmed the presence of four major peaks with retention times of 4.780, 5.767, 6.397 and 7.577 min. REC-7004 was found to lower lipid oxidation significantly (p < 0.05) at concentrations viz., 8 and 80 μg/ml respectively as compared to reduced glutathione, although the optimally protective dose was 80 μg/ml, which showed 59.5% inhibition of induction of linoleic acid degradation within first 24 h. The metal chelation activity of REC-7004 was found to increase concomitantly from 1 to 50 μg/ml. REC-7004 (10–50 μg/ml) exhibited significant metal chelation activity (p < 0.05), as compared to control, and maximum percentage inhibition (30%) of formation of iron-2,2′-bi-pyridyl complex was observed at 50 μg/ml, which correlated well with quercetin (34.9%), taken as standard. The reducing power of REC-7004 increased in a dose-dependent manner. The absorption unit value of REC-7004 was significantly lower (0.0183± 0.0033) as compared to butylated hydroxy toluene, a standard antioxidant (0.230± 0.091), confirming its high reducing ability. Superoxide ion scavenging ability of REC-7004 exhibited a dose-dependent increase (1–100 μg/ml) and was significantly higher (p < 0.05) than that of quercetin at lower concentrations (1–10 μg/ml), while at 100 μg/ml, both quercetin and REC-7004 scavenged over 90% superoxide anions. MTT assay in U87 cell line revealed an increase in percent survival of cells at doses between 25 and 125 μg/ml in case of drug + radiation group. In vivo evaluation of radio-protective efficacy in mice revealed that intraperitoneal administration of REC-7004 (maximally effective dose: 400 mg/kg b.w.) 30 min prior to lethal (10 Gy) total-body γ-irradiation rendered 83.3% survival. The ability of REC-7004 to inhibit lipid peroxidation induced by iron/ascorbate, radiation (250 Gy) and their combination [i.e., iron/ascorbate and radiation (250 Gy)], was also investigated and was found to decrease in a dose-dependent manner (0.05–2 mg/ml). The maximum percent inhibition of formation of MDA-TBA complex at 2 mg/ml in case of iron/ascorbate, radiation (250 Gy) and both i.e., iron/ascorbate with radiation (250 Gy) was 53.78, 63.07, and 51.76% respectively and were found to be comparable to that of quercetin. REC-7004 (1 μg/ml) also exhibited significant anti-hemolytic capacity by preventing radiation-induced membrane degeneration of human erythrocytes. In conclusion, Rhodiola renders in vitro and in vivo radioprotection via multifarious mechanisms that act in a synergistic manner.
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