Abstract Artemisia roxburghiana is used for the management of diabetes mellitus in the Indian sub... more Abstract Artemisia roxburghiana is used for the management of diabetes mellitus in the Indian subcontinent. The present work aimed to validate the traditional claim of the plant in diabetes mellitus. In vitro studies were conducted using α-glucosidase and α-amylase assays whereas streptozotocin-nicotinamide-induced diabetic Wistar rats were used for in vivo study. The aqueous-ethanol extract from the aerial parts was found to exhibit α-glucosidase and α-amylase inhibitory activities with the IC50 values of 31.0 and 17.2 mg/mL, respectively when compared with acarbose (IC50 = 8.6 and 16.25 mg/mL, respectively). The extract showed a significant glucose-lowering effect in diabetic rats at the doses of 200 and 400 mg/kg in a dose-dependent manner, while acarbose (10 mg/kg) was used as a standard. The results revealed that A. roxburghiana aerial parts showed antidiabetic activity via inhibiting α-glucosidase and α-amylase enzymes. The present study also validated the ethnomedicinal claim of the plant in diabetes mellitus. Graphical abstract
In the current scenario, developing treatments, identifying cures and formulating intervention st... more In the current scenario, developing treatments, identifying cures and formulating intervention strategies to fight against the COVID-19 outbreak, have become the major concern for researchers globally. Several studies have confirmed the molecular pathway of COVID-19 virulence that involves activation of proteins like angiotensin-converting enzyme 2 (ACE2), angiotensin (AT) receptor which is mainly AT1, and transmembrane protease serine 2 (TMPRSS2). Since the virus needs the involvement of these proteins, over and above its spike protein, for activation and infecting the host, it is obvious that targeting or blocking the activation of these molecules may play a critical role in the development of therapeutics for the cure and management of COVID-19. Many studies have been reported and several are ongoing to find a cure using these molecules as a target. While initially COVID-19 was thought to be affecting the human respiratory system, recent shreds of evidence indicate that this infection can reach beyond the lungs. It can invade and rampage almost all the organs in the body, and 'cytokine storm' is considered to be responsible for this. The reason for disease severity is not what matters anymore now, everyone is hoping for a cure soon enough. Therefore, there is an urgent need to search for some novel drugs/chemicals. Towards this end, natural products can contribute immensely since they have a long history of usage for the cure and management of various ailments, including viral infections. Various natural products (mainly from plants) have structural similarities to the molecules which by AT has been shown to interact with targets used by COVID-19 during its infection. This is indeed a positive indication for the development of natural products-based therapeutics. This aspect, therefore, warrants serious consideration for the cure and management of the COVID-19 pandemic.
Emodin (1,3,8-trihydroxy-6-methyl-anthraquinone) is a natural anthraquinone derivative that is pr... more Emodin (1,3,8-trihydroxy-6-methyl-anthraquinone) is a natural anthraquinone derivative that is present in numerous globally renowned herbal medicines. It is recognised as a protein tyrosine kinase inhibitor and as an anticancer drug, active against various tumour cells, including lung, breast, liver, and ovarian cancer cells. Recently, its role in combination chemotherapy with various allopathic medicines, to minimize their toxicity and to enhance their efficacy, has been studied. The use of emodin in these therapies is gaining popularity, due to fewer associated side effects compared with standard anticancer drugs. Emodin has a broad therapeutic window, and in addition to its antineoplastic activity, it displays anti-ulcer, anti-inflammatory, hepatoprotective, neuroprotective, antimicrobial, muscle relaxant, immunosuppressive and antifibrotic activities, in both in vitro and in vivo models. Although reviews on the anticancer activity of emodin have been published, none coherently unite all the pharmacological properties of emodin, particularly the anti-oxidant, antimicrobial, antidiabetic, immunosuppressive and hepatoprotective activities of the compound. Hence, in this review, all of the available data regarding the pharmacological properties of emodin are explored, with particular emphasis on the modes of action of the molecule. In addition, the manuscript details the occurrence, biosynthesis and chemical synthesis of the compound, as well as its toxic effects on biotic systems.
The present study was aimed to find out the chemical constituents of essential oils of Artemisia ... more The present study was aimed to find out the chemical constituents of essential oils of Artemisia nilagirica (Clarke) Pamp. and Artemisia capillaris Thunb. of Asteraceae family, growing in Garhwal region of India. The essential oils were obtained by hydro-distillation and subjected to detailed GC-MS analysis in order to determine the variation in their volatile constituents. While comparing the common constituents in both of the species, the remarkable variation was observed and it was 6.03, 3.251, 2.093, 33.73, 7.573, 15.041 and 8.00% for trans-caryophyllene, DL-limonene, α-pinene, α-thujone, β-myrcene, β-ocimene and β-thujone, respectively.
Diabetes mellitus is a metabolic disorder of multiple etiologies, characterized by chronic hyperg... more Diabetes mellitus is a metabolic disorder of multiple etiologies, characterized by chronic hyperglycemia together with the disturbance of carbohydrate, fat, protein metabolism resulting from a defect of insulin secretion, insulin action or both which affects most of the people in both developed and developing countries. Apart from insulin therapy (mainly for type 1 diabetes mellitus), several synthetic drugs are available in the market to treat diabetes, but the treatment with synthetic drugs is costly and the
Two antidiabetic compounds named 4-methoxybenzo[b]azet-2(1H)one (1) and 3β-hydroxy-35-(cyclohexyl... more Two antidiabetic compounds named 4-methoxybenzo[b]azet-2(1H)one (1) and 3β-hydroxy-35-(cyclohexyl-5′-propan-7′-one)-33-ethyl-34-methyl-bacteriohop-16-ene (2) together with stigmasterol and β-sitosterol were isolated from the aerial part of Roylea cinerea (D.Don) Baill. The structures of these compounds were elucidated by advanced spectroscopic methods, including two-dimensional NMR and MS techniques. These compounds were evaluated for their antidiabetic efficacy using in vitro and in vivo methods. Both compounds (1 and 2) showed a significant decline in blood glucose level of alloxan-induced diabetic rats at 10 mg/kg, p.o. when compared with glibenclamide at a similar dose. The in vitro studies revealed that compound 1 reduced α-amylase and α-glucosidase by 83.0 and 78.5%, respectively, whereas compound 2 reduced the same by 58.2 and 58.4%, respectively, at 100 μM. The present study supports the role of R. cinerea in Ayurvedic medicine for diabetes.
Renal cell carcinoma (RCC) is the most common neoplasm that occurs in the kidney and is marked by... more Renal cell carcinoma (RCC) is the most common neoplasm that occurs in the kidney and is marked by a unique biology, with a long history of poor response to conventional cancer treatments. In the past few years, there have been significant advancements to understand the biology of RCC. This has led to the introduction of novel targeted therapies in the management of patients with metastatic disease. Patients treated with targeted therapies for RCC had shown positive impact on overall survival, however, no cure is possible and patients need to undergo treatment for long periods of time, which raises challenges to manage the associated adverse events. Moreover, many patients may not respond to it and even response may not last long enough in the responders. Many inhibitors of the Mammalian target of Rapamycin (mTOR) signaling pathway are currently being used in treatment of advanced RCC. Studies showed that inhibitions of mTOR pathways induce Mitogen-Activated Protein Kinase (MAPK) escape cell death and cells become resistant to mTOR inhibitors. Because of this, there is a need to inhibit both pathways with their inhibitors comparatively for a better outcome and treatment of patients with RCC.
AYU (An International Quarterly Journal of Research in Ayurveda), 2015
Ayurvedic treatment is although highly effective; proper mode of action, pharmacology, pharmacoki... more Ayurvedic treatment is although highly effective; proper mode of action, pharmacology, pharmacokinetics, and pharmacovigilance of many important Ayurvedic drugs are still not fully explored. Moreover, the comprehensive knowledge of the basic ideologies of Ayurveda is poorly acceptable scientifically due to lack of evidence. In the modern time, when the Western medicinal system is reached almost at the top because of validated research and advanced techniques, there is an urgent need to validate basic principles as well as drugs used in the ayurvedic system of medicine with the help of advanced research methodology. Therefore, advancements in the ongoing research methodology are highly required for the promotion of Ayurveda.
Myricetin is a common plant-derived flavonoid and is well recognised for its nutraceuticals value... more Myricetin is a common plant-derived flavonoid and is well recognised for its nutraceuticals value. It is one of the key ingredients of various foods and beverages. The compound exhibits a wide range of activities that include strong anti-oxidant, anticancer, antidiabetic and anti-inflammatory activities. It displays several activities that are related to the central nervous system and numerous studies have suggested that the compound may be beneficial to protect against diseases such as Parkinson's and Alzheimer's. The use of myricetin as a preserving agent to extend the shelf life of foods containing oils and fats is attributed to the compound's ability to protect lipids against oxidation. A detailed search of existing literature revealed that there is currently no comprehensive review available on this important molecule. Hence, the present work includes the history, synthesis, pharmaceutical applications and toxicity studies of myricetin. This report also highlights structure-activity relationships and mechanisms of action for various biological activities.
Gingerols are the major pungent compounds present in the rhizomes of ginger (Zingiber officinale ... more Gingerols are the major pungent compounds present in the rhizomes of ginger (Zingiber officinale Roscoe) and are renowned for their contribution to human health and nutrition. Medicinal properties of ginger, including the alleviation of nausea, arthritis and pain, have been associated with the gingerols. Gingerol analogues are thermally labile and easily undergo dehydration reactions to form the corresponding shogaols, which impart the characteristic pungent taste to dried ginger. Both gingerols and shogaols exhibit a host of biological activities, ranging from anticancer, anti-oxidant, antimicrobial, anti-inflammatory and anti-allergic to various central nervous system activities. Shogaols are important biomarkers used for the quality control of many ginger-containing products, due to their diverse biological activities. In this review, a large body of available knowledge on the biosynthesis, chemical synthesis and pharmacological activities, as well as on the structure-activity relationships of various gingerols and shogaols, have been collated, coherently summarised and discussed. The manuscript highlights convincing evidence indicating that these phenolic compounds could serve as important lead molecules for the development of therapeutic agents to treat various life-threatening human diseases, particularly cancer. Inclusion of ginger or ginger extracts in nutraceutical formulations could provide valuable protection against diabetes, cardiac and hepatic disorders.
The fruit rind of Garcinia gummi-gutta, commonly known as Garcinia cambogia (syn.), is extensivel... more The fruit rind of Garcinia gummi-gutta, commonly known as Garcinia cambogia (syn.), is extensively used traditionally as a flavourant in fish curries due to its sharp sour taste. Additional ethnobotanical uses include its use as a digestive and a traditional remedy to treat bowel complaints, intestinal parasites and rheumatism. This small fruit, reminiscent of a pumpkin in appearance, is currently most popularly used and widely advertised as a weight-loss supplement. Studies have shown that the extracts as well as (−)-hydroxycitric acid (HCA), a main organic acid component of the fruit rind, exhibited anti-obesity activity including reduced food intake and body fat gain by regulating the serotonin levels related to satiety, increased fat oxidation and decreased de novo lipogenesis. HCA is a potent inhibitor of adenosine triphosphate-citrate lyase, a catalyst for the conversion process of citrate to acetyl-coenzyme A, which plays a key role in fatty acid, cholesterol and triglycerides syntheses. The crude extract or constituents from the plant also exerted hypolipidaemic, antidiabetic, anti-inflammatory, anticancer, anthelmintic, anticholinesterase and hepatoprotective activities in in vitro and in vivo models. Phytochemical studies of various plant parts revealed the presence of mainly xanthones (e.g. carbogiol) and benzophenones (e.g. garcinol) together with organic acids (e.g. HCA) and amino acids (e.g. gamma aminobutyric acid). Currently, a large number of G. cambogia/HCA dietary supplements for weight management are being sold although the possible toxicity associated with the regular use of these supplements has raised concerns. In most cases, complaints have been related to multicomponent formulations and at this stage G. cambogia has not been confirmed as the potentially toxic culprit. This review presents a scientific overview of G. cambogia with reference to relevant botanical aspects, ethnobotanical uses, phytochemistry and biological activity as well as toxicity.
Phytochemical investigation of the roots of Asparagus curillus Buch.-Ham. ex Roxb., furnished an ... more Phytochemical investigation of the roots of Asparagus curillus Buch.-Ham. ex Roxb., furnished an o-benzoquinone derivative named 5-hydroxy-7-oxabicyclo[4.2.0]octa-1,5-diene-3,4-dione (1) and a steroidal saponin named 25S-5E-spirostan-3E-yl-O-[E-D-glucopyranosyl-(1o4)-E-D-glucopyranoside] (2). Compounds 1 and 2 are reported for the first time from this source. However, the aglycone of 2, named sarsasapogenin, is well known and recognized for its medicinal utility in obesity and diabetes. The structures of 1 and 2 were elucidated by means of their chemical, physical, and spectral analyses, including 2D NMR techniques.
The gastroretentive drug delivery system is site-specific and allows the drug to remain in the st... more The gastroretentive drug delivery system is site-specific and allows the drug to remain in the stomach for a prolonged period of time so that it can be released in a controlled manner in gastrointestinal tract. The present study was carried out to develop a gastroretentive drug delivery system using isabgol as an excipient to prolong the residence time of the model drug lisinopril in the stomach. The gastroretentive ability of isabgol was increased by addition of NaHCO 3 as a gas-generating agent while its mucoadhesive property was enhanced by incorporation of HPMC-K 4 M. The drug, NaHCO 3 and HPMC-K 4 M were imbibed on isabgol-husk as per entrapment efficiency of the isabgol-husk. After drying, the product was filled in a hard gelatin capsule and evaluated for its buoyancy, mucoadhesive properties, swelling index and in vitro drug release. The lisinopril released through isabgol was delayed by 12 hours when compared to a preparation available on the market which released the complete drug in 0.5 hours. The drug release study of lisinopril from the formulation follows first order kinetics using a diffusion controlled mechanism. The results from the present study revealed that isabgol can be used as a potential excipient for the formulation of gastroretentive drug delivery systems in the near future.
A new flavonoid glycoside (1) has been isolated from the aerial parts of Salix denticulata (Salic... more A new flavonoid glycoside (1) has been isolated from the aerial parts of Salix denticulata (Salicaceae) together with five known compounds, β-sitosterol, 2,6-dihydroxy-4-methoxy acetophenone, eugenol-1-O-β-D-glucopyranoside, 1-O-β-D-(3'-benzoyl) salicyl alcohol and luteolin-7-O-β-D-glucopyranosyl-(1-6)-glucopyranoside. The structure of 1 was elucidated as 2',5-dihydroxy-3'-methoxyflavone-7-O-β-D-glucopyranoside by means of chemical and spectral data including 2D NMR studies.
ABSTRACT A triterpenoidal saponin, hederagenin-3-O-{β-D-arabinopyranosyl (1→4) α-L-rhamnopyranosi... more ABSTRACT A triterpenoidal saponin, hederagenin-3-O-{β-D-arabinopyranosyl (1→4) α-L-rhamnopyranoside} (1); a flavonoid glycoside, flavonone-4’-hydroxy 7-O-{β-D-glucopyranosyl (1→6) β-D-xylopyranoside} 5’-O-β-D-glucopyranoside (2) and a xanthone glycoside, xanthone-1-hydroxy-3-methoxy-7-O-{β -D-xylopyranosyl (1→ 4) α -L-rhamnopyranosyl-(1→4) β-D-xylopyranosyl (1→3) β-D-xylopyranoside} (3) along with five known compounds, quercetin-7-O-β-Dglucopyranoside; β-sitosterol-β-D-glucopyranoside, quercetin; β-sitosterol and oleanolic acid were isolated from the flowers of Rhododendron barbatum. Their structures were elucidated by means of chemical and spectral studies.
Abstract Artemisia roxburghiana is used for the management of diabetes mellitus in the Indian sub... more Abstract Artemisia roxburghiana is used for the management of diabetes mellitus in the Indian subcontinent. The present work aimed to validate the traditional claim of the plant in diabetes mellitus. In vitro studies were conducted using α-glucosidase and α-amylase assays whereas streptozotocin-nicotinamide-induced diabetic Wistar rats were used for in vivo study. The aqueous-ethanol extract from the aerial parts was found to exhibit α-glucosidase and α-amylase inhibitory activities with the IC50 values of 31.0 and 17.2 mg/mL, respectively when compared with acarbose (IC50 = 8.6 and 16.25 mg/mL, respectively). The extract showed a significant glucose-lowering effect in diabetic rats at the doses of 200 and 400 mg/kg in a dose-dependent manner, while acarbose (10 mg/kg) was used as a standard. The results revealed that A. roxburghiana aerial parts showed antidiabetic activity via inhibiting α-glucosidase and α-amylase enzymes. The present study also validated the ethnomedicinal claim of the plant in diabetes mellitus. Graphical abstract
In the current scenario, developing treatments, identifying cures and formulating intervention st... more In the current scenario, developing treatments, identifying cures and formulating intervention strategies to fight against the COVID-19 outbreak, have become the major concern for researchers globally. Several studies have confirmed the molecular pathway of COVID-19 virulence that involves activation of proteins like angiotensin-converting enzyme 2 (ACE2), angiotensin (AT) receptor which is mainly AT1, and transmembrane protease serine 2 (TMPRSS2). Since the virus needs the involvement of these proteins, over and above its spike protein, for activation and infecting the host, it is obvious that targeting or blocking the activation of these molecules may play a critical role in the development of therapeutics for the cure and management of COVID-19. Many studies have been reported and several are ongoing to find a cure using these molecules as a target. While initially COVID-19 was thought to be affecting the human respiratory system, recent shreds of evidence indicate that this infection can reach beyond the lungs. It can invade and rampage almost all the organs in the body, and 'cytokine storm' is considered to be responsible for this. The reason for disease severity is not what matters anymore now, everyone is hoping for a cure soon enough. Therefore, there is an urgent need to search for some novel drugs/chemicals. Towards this end, natural products can contribute immensely since they have a long history of usage for the cure and management of various ailments, including viral infections. Various natural products (mainly from plants) have structural similarities to the molecules which by AT has been shown to interact with targets used by COVID-19 during its infection. This is indeed a positive indication for the development of natural products-based therapeutics. This aspect, therefore, warrants serious consideration for the cure and management of the COVID-19 pandemic.
Emodin (1,3,8-trihydroxy-6-methyl-anthraquinone) is a natural anthraquinone derivative that is pr... more Emodin (1,3,8-trihydroxy-6-methyl-anthraquinone) is a natural anthraquinone derivative that is present in numerous globally renowned herbal medicines. It is recognised as a protein tyrosine kinase inhibitor and as an anticancer drug, active against various tumour cells, including lung, breast, liver, and ovarian cancer cells. Recently, its role in combination chemotherapy with various allopathic medicines, to minimize their toxicity and to enhance their efficacy, has been studied. The use of emodin in these therapies is gaining popularity, due to fewer associated side effects compared with standard anticancer drugs. Emodin has a broad therapeutic window, and in addition to its antineoplastic activity, it displays anti-ulcer, anti-inflammatory, hepatoprotective, neuroprotective, antimicrobial, muscle relaxant, immunosuppressive and antifibrotic activities, in both in vitro and in vivo models. Although reviews on the anticancer activity of emodin have been published, none coherently unite all the pharmacological properties of emodin, particularly the anti-oxidant, antimicrobial, antidiabetic, immunosuppressive and hepatoprotective activities of the compound. Hence, in this review, all of the available data regarding the pharmacological properties of emodin are explored, with particular emphasis on the modes of action of the molecule. In addition, the manuscript details the occurrence, biosynthesis and chemical synthesis of the compound, as well as its toxic effects on biotic systems.
The present study was aimed to find out the chemical constituents of essential oils of Artemisia ... more The present study was aimed to find out the chemical constituents of essential oils of Artemisia nilagirica (Clarke) Pamp. and Artemisia capillaris Thunb. of Asteraceae family, growing in Garhwal region of India. The essential oils were obtained by hydro-distillation and subjected to detailed GC-MS analysis in order to determine the variation in their volatile constituents. While comparing the common constituents in both of the species, the remarkable variation was observed and it was 6.03, 3.251, 2.093, 33.73, 7.573, 15.041 and 8.00% for trans-caryophyllene, DL-limonene, α-pinene, α-thujone, β-myrcene, β-ocimene and β-thujone, respectively.
Diabetes mellitus is a metabolic disorder of multiple etiologies, characterized by chronic hyperg... more Diabetes mellitus is a metabolic disorder of multiple etiologies, characterized by chronic hyperglycemia together with the disturbance of carbohydrate, fat, protein metabolism resulting from a defect of insulin secretion, insulin action or both which affects most of the people in both developed and developing countries. Apart from insulin therapy (mainly for type 1 diabetes mellitus), several synthetic drugs are available in the market to treat diabetes, but the treatment with synthetic drugs is costly and the
Two antidiabetic compounds named 4-methoxybenzo[b]azet-2(1H)one (1) and 3β-hydroxy-35-(cyclohexyl... more Two antidiabetic compounds named 4-methoxybenzo[b]azet-2(1H)one (1) and 3β-hydroxy-35-(cyclohexyl-5′-propan-7′-one)-33-ethyl-34-methyl-bacteriohop-16-ene (2) together with stigmasterol and β-sitosterol were isolated from the aerial part of Roylea cinerea (D.Don) Baill. The structures of these compounds were elucidated by advanced spectroscopic methods, including two-dimensional NMR and MS techniques. These compounds were evaluated for their antidiabetic efficacy using in vitro and in vivo methods. Both compounds (1 and 2) showed a significant decline in blood glucose level of alloxan-induced diabetic rats at 10 mg/kg, p.o. when compared with glibenclamide at a similar dose. The in vitro studies revealed that compound 1 reduced α-amylase and α-glucosidase by 83.0 and 78.5%, respectively, whereas compound 2 reduced the same by 58.2 and 58.4%, respectively, at 100 μM. The present study supports the role of R. cinerea in Ayurvedic medicine for diabetes.
Renal cell carcinoma (RCC) is the most common neoplasm that occurs in the kidney and is marked by... more Renal cell carcinoma (RCC) is the most common neoplasm that occurs in the kidney and is marked by a unique biology, with a long history of poor response to conventional cancer treatments. In the past few years, there have been significant advancements to understand the biology of RCC. This has led to the introduction of novel targeted therapies in the management of patients with metastatic disease. Patients treated with targeted therapies for RCC had shown positive impact on overall survival, however, no cure is possible and patients need to undergo treatment for long periods of time, which raises challenges to manage the associated adverse events. Moreover, many patients may not respond to it and even response may not last long enough in the responders. Many inhibitors of the Mammalian target of Rapamycin (mTOR) signaling pathway are currently being used in treatment of advanced RCC. Studies showed that inhibitions of mTOR pathways induce Mitogen-Activated Protein Kinase (MAPK) escape cell death and cells become resistant to mTOR inhibitors. Because of this, there is a need to inhibit both pathways with their inhibitors comparatively for a better outcome and treatment of patients with RCC.
AYU (An International Quarterly Journal of Research in Ayurveda), 2015
Ayurvedic treatment is although highly effective; proper mode of action, pharmacology, pharmacoki... more Ayurvedic treatment is although highly effective; proper mode of action, pharmacology, pharmacokinetics, and pharmacovigilance of many important Ayurvedic drugs are still not fully explored. Moreover, the comprehensive knowledge of the basic ideologies of Ayurveda is poorly acceptable scientifically due to lack of evidence. In the modern time, when the Western medicinal system is reached almost at the top because of validated research and advanced techniques, there is an urgent need to validate basic principles as well as drugs used in the ayurvedic system of medicine with the help of advanced research methodology. Therefore, advancements in the ongoing research methodology are highly required for the promotion of Ayurveda.
Myricetin is a common plant-derived flavonoid and is well recognised for its nutraceuticals value... more Myricetin is a common plant-derived flavonoid and is well recognised for its nutraceuticals value. It is one of the key ingredients of various foods and beverages. The compound exhibits a wide range of activities that include strong anti-oxidant, anticancer, antidiabetic and anti-inflammatory activities. It displays several activities that are related to the central nervous system and numerous studies have suggested that the compound may be beneficial to protect against diseases such as Parkinson's and Alzheimer's. The use of myricetin as a preserving agent to extend the shelf life of foods containing oils and fats is attributed to the compound's ability to protect lipids against oxidation. A detailed search of existing literature revealed that there is currently no comprehensive review available on this important molecule. Hence, the present work includes the history, synthesis, pharmaceutical applications and toxicity studies of myricetin. This report also highlights structure-activity relationships and mechanisms of action for various biological activities.
Gingerols are the major pungent compounds present in the rhizomes of ginger (Zingiber officinale ... more Gingerols are the major pungent compounds present in the rhizomes of ginger (Zingiber officinale Roscoe) and are renowned for their contribution to human health and nutrition. Medicinal properties of ginger, including the alleviation of nausea, arthritis and pain, have been associated with the gingerols. Gingerol analogues are thermally labile and easily undergo dehydration reactions to form the corresponding shogaols, which impart the characteristic pungent taste to dried ginger. Both gingerols and shogaols exhibit a host of biological activities, ranging from anticancer, anti-oxidant, antimicrobial, anti-inflammatory and anti-allergic to various central nervous system activities. Shogaols are important biomarkers used for the quality control of many ginger-containing products, due to their diverse biological activities. In this review, a large body of available knowledge on the biosynthesis, chemical synthesis and pharmacological activities, as well as on the structure-activity relationships of various gingerols and shogaols, have been collated, coherently summarised and discussed. The manuscript highlights convincing evidence indicating that these phenolic compounds could serve as important lead molecules for the development of therapeutic agents to treat various life-threatening human diseases, particularly cancer. Inclusion of ginger or ginger extracts in nutraceutical formulations could provide valuable protection against diabetes, cardiac and hepatic disorders.
The fruit rind of Garcinia gummi-gutta, commonly known as Garcinia cambogia (syn.), is extensivel... more The fruit rind of Garcinia gummi-gutta, commonly known as Garcinia cambogia (syn.), is extensively used traditionally as a flavourant in fish curries due to its sharp sour taste. Additional ethnobotanical uses include its use as a digestive and a traditional remedy to treat bowel complaints, intestinal parasites and rheumatism. This small fruit, reminiscent of a pumpkin in appearance, is currently most popularly used and widely advertised as a weight-loss supplement. Studies have shown that the extracts as well as (−)-hydroxycitric acid (HCA), a main organic acid component of the fruit rind, exhibited anti-obesity activity including reduced food intake and body fat gain by regulating the serotonin levels related to satiety, increased fat oxidation and decreased de novo lipogenesis. HCA is a potent inhibitor of adenosine triphosphate-citrate lyase, a catalyst for the conversion process of citrate to acetyl-coenzyme A, which plays a key role in fatty acid, cholesterol and triglycerides syntheses. The crude extract or constituents from the plant also exerted hypolipidaemic, antidiabetic, anti-inflammatory, anticancer, anthelmintic, anticholinesterase and hepatoprotective activities in in vitro and in vivo models. Phytochemical studies of various plant parts revealed the presence of mainly xanthones (e.g. carbogiol) and benzophenones (e.g. garcinol) together with organic acids (e.g. HCA) and amino acids (e.g. gamma aminobutyric acid). Currently, a large number of G. cambogia/HCA dietary supplements for weight management are being sold although the possible toxicity associated with the regular use of these supplements has raised concerns. In most cases, complaints have been related to multicomponent formulations and at this stage G. cambogia has not been confirmed as the potentially toxic culprit. This review presents a scientific overview of G. cambogia with reference to relevant botanical aspects, ethnobotanical uses, phytochemistry and biological activity as well as toxicity.
Phytochemical investigation of the roots of Asparagus curillus Buch.-Ham. ex Roxb., furnished an ... more Phytochemical investigation of the roots of Asparagus curillus Buch.-Ham. ex Roxb., furnished an o-benzoquinone derivative named 5-hydroxy-7-oxabicyclo[4.2.0]octa-1,5-diene-3,4-dione (1) and a steroidal saponin named 25S-5E-spirostan-3E-yl-O-[E-D-glucopyranosyl-(1o4)-E-D-glucopyranoside] (2). Compounds 1 and 2 are reported for the first time from this source. However, the aglycone of 2, named sarsasapogenin, is well known and recognized for its medicinal utility in obesity and diabetes. The structures of 1 and 2 were elucidated by means of their chemical, physical, and spectral analyses, including 2D NMR techniques.
The gastroretentive drug delivery system is site-specific and allows the drug to remain in the st... more The gastroretentive drug delivery system is site-specific and allows the drug to remain in the stomach for a prolonged period of time so that it can be released in a controlled manner in gastrointestinal tract. The present study was carried out to develop a gastroretentive drug delivery system using isabgol as an excipient to prolong the residence time of the model drug lisinopril in the stomach. The gastroretentive ability of isabgol was increased by addition of NaHCO 3 as a gas-generating agent while its mucoadhesive property was enhanced by incorporation of HPMC-K 4 M. The drug, NaHCO 3 and HPMC-K 4 M were imbibed on isabgol-husk as per entrapment efficiency of the isabgol-husk. After drying, the product was filled in a hard gelatin capsule and evaluated for its buoyancy, mucoadhesive properties, swelling index and in vitro drug release. The lisinopril released through isabgol was delayed by 12 hours when compared to a preparation available on the market which released the complete drug in 0.5 hours. The drug release study of lisinopril from the formulation follows first order kinetics using a diffusion controlled mechanism. The results from the present study revealed that isabgol can be used as a potential excipient for the formulation of gastroretentive drug delivery systems in the near future.
A new flavonoid glycoside (1) has been isolated from the aerial parts of Salix denticulata (Salic... more A new flavonoid glycoside (1) has been isolated from the aerial parts of Salix denticulata (Salicaceae) together with five known compounds, β-sitosterol, 2,6-dihydroxy-4-methoxy acetophenone, eugenol-1-O-β-D-glucopyranoside, 1-O-β-D-(3'-benzoyl) salicyl alcohol and luteolin-7-O-β-D-glucopyranosyl-(1-6)-glucopyranoside. The structure of 1 was elucidated as 2',5-dihydroxy-3'-methoxyflavone-7-O-β-D-glucopyranoside by means of chemical and spectral data including 2D NMR studies.
ABSTRACT A triterpenoidal saponin, hederagenin-3-O-{β-D-arabinopyranosyl (1→4) α-L-rhamnopyranosi... more ABSTRACT A triterpenoidal saponin, hederagenin-3-O-{β-D-arabinopyranosyl (1→4) α-L-rhamnopyranoside} (1); a flavonoid glycoside, flavonone-4’-hydroxy 7-O-{β-D-glucopyranosyl (1→6) β-D-xylopyranoside} 5’-O-β-D-glucopyranoside (2) and a xanthone glycoside, xanthone-1-hydroxy-3-methoxy-7-O-{β -D-xylopyranosyl (1→ 4) α -L-rhamnopyranosyl-(1→4) β-D-xylopyranosyl (1→3) β-D-xylopyranoside} (3) along with five known compounds, quercetin-7-O-β-Dglucopyranoside; β-sitosterol-β-D-glucopyranoside, quercetin; β-sitosterol and oleanolic acid were isolated from the flowers of Rhododendron barbatum. Their structures were elucidated by means of chemical and spectral studies.
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