Endometriosis is a chronic inflammatory condition affecting up to 10% of women of reproductive ag... more Endometriosis is a chronic inflammatory condition affecting up to 10% of women of reproductive age and this, depending on its severity, very often leads to infertility. New research has shed light on the role of underlying endometritis due to the presence of inflammatory, nonoestrogen metabolising microbiome at the mucosal interface and this in turn leads to the activation of aggressive, non-tolerant immune cells in the endometrium. These immune cells require the presence of toleranceinducing commensals such as Lactobacilli so as to allow the implantation of the fertilised egg. New therapies should be holistic and address both the dysbiosis as well as immune abnormalities. Routine immune monitoring of the immune cells derived from the endometrium and/or microbial profiling should recommended to better predict assisted reproduction outcomes in these couples.
The research results presented in this book describe the quest of Cape Kingdom Nutraceuticals, Pr... more The research results presented in this book describe the quest of Cape Kingdom Nutraceuticals, Prof. Patrick Bouic and Prof. Barbara Huisamen to scientifically validate the health-promoting properties of an aqueous extract of the plant Agathosma. To accomplish this, they used both in vitro and in vivo models to understand and underscore the anecdotal information regarding the benefits of this product. Cell-based studies were utilised to highlight anti-inflammatory and anti-diabetic effects, whereas animal-based studies were utilised to confirm the anti-diabetic effects while further elaborating the anti-obesity properties. In addition, technology aimed at small animals was used to demonstrate, by means of blood pressure measurement, anti-hypertensive effects, while ex vivo perfused hearts were studied to show that this extract could also protect the heart against an ischaemic incident. The research summarised in this book is novel, original and has not been published previously, and the results presented validate future use of this extract for the above-mentioned health-promoting properties. In view of the current pandemic of obesity and non-communicable diseases, the research results presented in this book will be of special interest to the scientific community and health practitioners interested in cardiometabolic diseases and nutraceuticals as an alternative treatment option. In light of the failure of many pharmaceuticals to curb noncommunicable diseases, these results are deemed of high importance.
The pharmaceutical industry is in need of rapid and accurate methods to screen new drug leads for... more The pharmaceutical industry is in need of rapid and accurate methods to screen new drug leads for intestinal permeability potential in the early stages of drug discovery. Excised human jejunal mucosa was used to investigate the permeability of the small intestine to four oral drugs, using a flow-through diffusion system. The four drugs were selected as representative model compounds of drug classes 1 and 3 according to the biopharmaceutics classification system (BCS). The drugs selected were zidovudine, propranolol HCl, didanosine, and enalapril maleate. Permeability values from our in vitro diffusion model were compared with the BCS permeability classification and in vivo and in vitro gastrointestinal drug permeability. The flux rates of the four drugs were influenced by the length of the experiment. Both class 1 drugs showed a significantly higher mean flux rate between 2 and 6 h across the jejunal mucosa compared to the class 3 drugs. The results are therefore in line with the drugs' BCS classification. The results of this study show that the permeability values of jejunal mucosa obtained with the flow-through diffusion system are good predictors of the selected BCS class 1 and 3 drugs' permeation, and it concurred with other in vitro and in vivo studies.
Induction of interleukin-6 (IL-6) secretion by whole blood cultures (WBC) was used as an in vitro... more Induction of interleukin-6 (IL-6) secretion by whole blood cultures (WBC) was used as an in vitro assay system for pyrogen-induced inflammatory reactions. The assay system was very sensitive to Eschericia coli (E.coli) endotoxin (< 10 pg/ml). The potential pyrogenic effects of human serum albumin (HSA), Fibronectin (Fn) and stabilised human serum (SHS) solutions were analyzed using this system. None of
South African journal of physiotherapy, Feb 18, 2007
Introduction: Music, processed by the brain, has a strong impact on the emotions and health. The ... more Introduction: Music, processed by the brain, has a strong impact on the emotions and health. The Magnificat in D major of JS Bach communicates not only a positive emotion of happiness but also motivational behaviour. Infectious lung conditions are often associated with negative emotions which develop due to physiological changes. The hormonal action of the hypothalamuspituitary-adrenal axes (HPA) could be negatively affected by emotions of anger and depression. This will result in a disturbance of the mind-body interaction. Music therefore can exert a powerful influence on therapeutic benefits by changing the psychological status and the immune endocrine functions. The purpose of this study was to determine the effect of music, during respiratory physiotherapy treatment on a) the emotional status, b) neuroendocrine responses, c) immune functions and d) lung functions of subjects with infected lung conditions. Method and Materials: Forty subjects attending physiotherapy treatment was selected according to set criteria and randomly assigned to an experimental and control group. The parameters (Profile Of Mood State [POMS]; CD4: CD8 cell ratios; Cortisol; the Cortisol: DHEA ratio; PF; FEV1; FVC and FEV1/FVC %) were measured on day 1 before the treatment and on day 3 after the treatment. Data were analysed with Statistica (Statsoft) using the Repeated ANOVA tests. Results: Results indicated that the intervention of music had a positive effect on the immunological parameter (CD4+:CD8+ cell ratios) and on the cortisol and cortisol:DHEA ratio levels. At the same time the psychological status as measured by Profile of Mood States (POMS scale) improved with a significant improvement in the lung functions. Conclusion: The research provided sufficient scientific evidence that music affects both the biomedical and psychosomatic aspects of infectious lung conditions.
Current Opinion in Clinical Nutrition and Metabolic Care, Nov 1, 2001
Although plant sterols (phytosterols) were chemically described in 1922, their biological role in... more Although plant sterols (phytosterols) were chemically described in 1922, their biological role in human and animal health has been underestimated. Their ability to control cholesterol plasma levels in hypercholesterolimic patients was first described in 1983 when the structure of phytosterols implied that they could, by steric hindrance, inhibit the absorption of cholesterol from our diets. This has led to the development of functional foods containing high contents of these plant molecules or their esters as cholesterol controlling foods. Over the last 15 years, however, several reports have appeared in the literature indicating that phytosterols have some immunological activity as highlighted in animal models of inflammation or even in in-vitro and in-vivo models of cancer (colorectal and breast cancer). These findings were paralleled by epidemiological studies correlating the reduced risk of numerous diseases and the dietary intake of phytosterols. It is only in the last 10 years, however, that their direct immune modulatory activity on human lymphocytes has been proven and the mechanism of action in cancer cells has been elucidated. The use of phytosterols as supportive therapies in certain chronic conditions has been tested under clinical trial conditions. This review presents a summary of the in-vitro and in-vivo studies published to date.
African Journal of Traditional, Complementary and Alternative Medicines, Aug 12, 2014
Background: Studies have suggested an increasing practice of concurrent herb-drug consumption. On... more Background: Studies have suggested an increasing practice of concurrent herb-drug consumption. One of the major clinical risks of such concomitant herb-drug use is pharmacokinetic herb-drug interaction (HDI). This is brought about by the ability of phytochemicals to inhibit or induce the activity of metabolic enzymes. The aim of this study was to investigate the potential of the crude aqueous extracts of three popular medicinal herbs used in South Africa to inhibit major cytochrome P450 (CYP) enzymes. Materials and Methods: The extracts of Bowiea volubilis, Spirostachys africana and Tulbaghia violacea were incubated with human liver microsomes (HLM) to monitor the phenacetin O-deethylation, diclofenac 4'-hydroxylation, S-mephenytoin 4'-hydroxylation and testosterone 6βhydroxylation as respective probe reactions for CYP1A2, CYP2C9, CYP2C19 and CYP3A4. The inhibitory activity, where observed, was profiled against the extract concentration. Results: Extracts of Bowiea volubilis inhibited the metabolic activity of CYP1A2 and CYP3A4 with IC 50 values of 92.3 ± 5.5 g/mL and 8.1 ± 0.6 g/mL respectively. Similar observation with Spirostachys africana showed inhibitory activity against CYP1A2 and CYP3A4 with respective IC 50 values of 14.3 ± 0.6 g/mL and 47.4 ± 2.4 g/mL. Tulbaghia violacea demonstrated relatively weak inhibitory activity against CYP1A2 (767.4 ± 10.8 g/mL) and CYP2C9 (921 ± 15.3 g/mL). Conclusion: The results suggest the potential for HDI between the herbs and the substrates of the affected enzymes, if sufficient in vivo concentration is attained.
Context: Aqueous decoction of Hypoxis hemerocallidea Fisch. & C.A. Mey. (Hypoxidaceae) (Hypoxis) ... more Context: Aqueous decoction of Hypoxis hemerocallidea Fisch. & C.A. Mey. (Hypoxidaceae) (Hypoxis) is widely consumed in Southern Africa by people living with HIV/AIDS, some of whom are on ARV and other medications. Objective: The aim of this study was to investigate the potential of the crude aqueous extracts of Hypoxis to inhibit major forms of CYP450 and transport proteins. Materials and methods: Corms of Hypoxis were water-extracted and incubated (in graded concentrations: 1-100 mg/mL) with human liver microsomes (20 min) to monitor the effects on phenacetin O-deethylation, coumarin 7-hydroxylation, bupropion hydroxylation, paclitaxel 6a-hydroxylation, diclofenac 4 0-hydroxylation, S-mephenytoin 4 0-hydroxylation, bufuralol 1 0-hydroxylation, chlorzoxazone 6-hydroxylation, midazolam 1 0-hydroxylation and testosterone 6b-hydroxylation as markers for the metabolic activities of CYP1A2, 2A6, 2B6, 2C8, 2C9, 2C19, 2D6, 2E1 and 3A4/5, respectively. The generation of metabolites were monitored and quantified with the aid of LC-MS/MS. The potential of the extracts to inhibit human ATPbinding cassette transporter activity was assessed using recombinant MDCKII and LLC-PK1 cells over-expressing human breast cancer resistant protein and human P-glycoprotein , respectively (with Ko143 and cyclosporin A as positive controls). Similar assessment was performed with human organic anion transporting polypeptide (OATP1B1 and OATP1B3) using recombinant HEK293 cells over-expressing OATP1B1 and OATP1B3, respectively (with rifamycin and 10 mM atorvastatin as positive controls). Results: Extracts of Hypoxis inhibited the production of the metabolites of the substrates of the following enzymes (as compared to controls) with the indicated IC 50 values (mg/mL): CYP1A2 (120.6), CYP2A6 (210.8), CYP2B6 (98.5), CYP2C8 (195.2), CYP2C9 (156) and CYP3A4/5 (185.4). The inhibition of the uptake activity of OATP1B1 and OATP1B3 were also observed with IC 50 values of 93.4 and 244.8 mg/mL, respectively. Discussion: Extract concentrations higher than the estimated IC 50 values are achievable in the gastrointestinal tract when traditional doses of Hypoxis are considered. This may have profound effects on presystemic metabolism of the drug substrates. If absorbed, systemic inhibition of metabolic enzymes/transporters by Hypoxis may be expected. Conclusion: The result suggests that there is the potential for HDI between Hypoxis and the substrates of the affected enzymes/transporters, if sufficient in vivo concentration of Hypoxis extracts is attained.
a,-Microglobulin (a Im), a glycoprotein heterogeneous in charge, was reported to occur both as a ... more a,-Microglobulin (a Im), a glycoprotein heterogeneous in charge, was reported to occur both as a 31-kilodalton (kd) monomer [low mol. wt a: Im (LMW-a Im)] and as polymers or complexes formed with other plasma proteins including IgA [high mol. wt a: Im (HMW-a lm)]. The present study was designed to characterize HMW-a Im in normal human serum and in myeloma sera. The following sera were selected: five IgG, 16 IgA and four Bence-Jones protein myelomas. a lm was identified by specific monoclonal antibodies in competitive radioimmunoassay and solid-phase ELISA. HMW-c(lm was found to be associated almost exclusively with monomeric IgA and possibly in very small proportion with dimeric IgA. Ever, in cases of predominantly dimeric IgA myelomas, alm was associated with the monomeric form of the monoclonal IgA. The molar ratio of HMW-a Im to monomeric IgA never exceeded 3.5% and it was estimated to range from 0.5 to 1.4% in normal serum. No association with other proteins than IgA and no a lm polymers were found in IgA myeloma. Two types of HMW-a Im-IgA complexes were found: (a) those that were dissociable into IgA and LMW-a Im after mild reduction, and (b) those which were dissociated only after complete reduction of the complexes into IgA and an 88-90-kd component bearing c(Im but no IgA epitopes. It was concluded that either of the two molecular species of a Im bearing common epitopes, with apparent mol. wts of 31,000 and 88,000-90,000, respectively, could form stable complexes with monomeric IgA. The association is likely to be performed through disulfide bridges. Nearly all the 88-90-kd but only a small proportion of the 31-kd component is associated with IgA.
Sutherlandia frutescens (ST) is a popular medicinal herb widely consumed in Africa by people livi... more Sutherlandia frutescens (ST) is a popular medicinal herb widely consumed in Africa by people living with HIV/AIDS. Concomitant use with antiretroviral drugs has generated concerns of herb-drug interaction. This study investigated the inhibitory effects of the crude extracts of ST on the major cytochrome P450 isozymes employing pooled human liver microsomes. Its effect on the metabolic clearance of midazolam using cryopreserved hepatocytes was also monitored. The potential of ST to inhibit human ATP-binding cassette (ABC) transporters (P-gp and BCRP) and the human organic anion transporting polypeptide (OATP1B1 and OATP1B3) activity was assessed using cell lines overexpressing the transporter proteins. ST showed inhibitory potency for CYP1A2 (IC 50 = 41.0 µg/mL), CYP2A6 (IC 50 = 160 µg/mL), CYP2B6 (IC 50 = 20.0 µg/mL), CYP2C8 (IC 50 = 22.4 µg/mL), CYP2C9 (IC 50 = 23.0 µg/mL), CYP2C19 (IC 50 = 35.9 µg/mL) and CYP3A4/5 (IC 50 = 17.5 µg/mL [with midazolam1'-hydroxylation]; IC 50 = 28.3 µg/mL [with testosterone 6β-hydroxylation]). Timedependent (irreversible) inhibition by ST was observed for CYP3A4/5 (KI = 296 µg/mL, kinact = 0.063 min-1) under the conditions of this study. ST also delays the production of midazolam metabolites in the hepatocytes, decreasing its clearance by 40%. Further, ST inhibited P-gp (IC 50 = 324.8 µg/mL); OATP1B1 (IC 50 = 10.4 µg/mL, and of OATP1B3 (IC 50 = 6.6 µg/mL). The result indicates the potential for HDI between ST and the substrates of the affected enzymes, if sufficient in vivo concentration of ST is attained.
1. This study investigated the mechanism underlying Echinacea-mediated induction of CYP1A2, CYP3A... more 1. This study investigated the mechanism underlying Echinacea-mediated induction of CYP1A2, CYP3A4 and MDR1 in terms of human pregnane X receptor (PXR) activation. 2. Crude extracts and fractions of Echinacea purpurea were tested for PXR activation in HepG2 cells by a reporter gene assay. Quantitative real-time PCR was carried out to determine their effects on CYP1A2 and CYP3A4 mRNA expressions. Capsules and fractions were risk ranked as high, intermediate and remote risk of drug-metabolizing enzymes induction based on EC 50 values determined for respective CYPs. 3. Fractions F 1 , F 2 and capsule (2660) strongly activated PXR with 5-, 4-and 3.5-fold increase in activity, respectively. Echinacea preparations potentiated up-regulation of CYP1A2, CYP3A4 and MDR1 via PXR activation. 4. Thus E. purpurea preparations cause herb-drug interaction by up-regulating CYP1A2, CYP3A4 and P-gp via PXR activation.
Journal of Histochemistry and Cytochemistry, Jul 1, 1984
The tissue distribution of rat a,-microglobulin (a1-m) was studied by indirect immunofluorescence... more The tissue distribution of rat a,-microglobulin (a1-m) was studied by indirect immunofluorescence in various rat tissues using a polyvalent rabbit antiserum to the purified antigen and a monoclonal antibody (H23) to the human homologue, in parallel with a polyclonal anti-rat IgA antiserum. It was found that all tissues stained by anti-IgA were also a1-m positive; these tissues included tissues of the stomach, duodenum, ileum, colon, pancreas, trachea, esophagus and jejunum. However, the observation that IgA plasma cells as well as secretory cells, while positively stained by anti-IgA, are a1-m negative suggests that the association between IgA and a1-m occurs at a postsecretory stage, after the IgA molecules have been transported across the epithelial cells. Additionally, hepatocytes were intensely stained by anti-a1-m antibodies, indicating that the liver, as already suggested by metabolic studies on isolated guinea-pig liver explants, may be responsible for the synthesis of this protein. Among lymphoid tissues, an intense and homogeneous staining was observed in the thymus and the white pulp of the spleen. Sections of lymph nodes, might help to resolve the discrepancies among the reports on human a1-m. So far, however, only guinea-pig a1-m has been characterized, by Akerstr#{246}m and Berggard (2). These authors
Calcium-dependent natural killer and calcium-independent natural cytotoxic activities in an IL-2-... more Calcium-dependent natural killer and calcium-independent natural cytotoxic activities in an IL-2-dependent killer cell line.
Endometriosis is a chronic inflammatory condition affecting up to 10% of women of reproductive ag... more Endometriosis is a chronic inflammatory condition affecting up to 10% of women of reproductive age and this, depending on its severity, very often leads to infertility. New research has shed light on the role of underlying endometritis due to the presence of inflammatory, nonoestrogen metabolising microbiome at the mucosal interface and this in turn leads to the activation of aggressive, non-tolerant immune cells in the endometrium. These immune cells require the presence of toleranceinducing commensals such as Lactobacilli so as to allow the implantation of the fertilised egg. New therapies should be holistic and address both the dysbiosis as well as immune abnormalities. Routine immune monitoring of the immune cells derived from the endometrium and/or microbial profiling should recommended to better predict assisted reproduction outcomes in these couples.
The research results presented in this book describe the quest of Cape Kingdom Nutraceuticals, Pr... more The research results presented in this book describe the quest of Cape Kingdom Nutraceuticals, Prof. Patrick Bouic and Prof. Barbara Huisamen to scientifically validate the health-promoting properties of an aqueous extract of the plant Agathosma. To accomplish this, they used both in vitro and in vivo models to understand and underscore the anecdotal information regarding the benefits of this product. Cell-based studies were utilised to highlight anti-inflammatory and anti-diabetic effects, whereas animal-based studies were utilised to confirm the anti-diabetic effects while further elaborating the anti-obesity properties. In addition, technology aimed at small animals was used to demonstrate, by means of blood pressure measurement, anti-hypertensive effects, while ex vivo perfused hearts were studied to show that this extract could also protect the heart against an ischaemic incident. The research summarised in this book is novel, original and has not been published previously, and the results presented validate future use of this extract for the above-mentioned health-promoting properties. In view of the current pandemic of obesity and non-communicable diseases, the research results presented in this book will be of special interest to the scientific community and health practitioners interested in cardiometabolic diseases and nutraceuticals as an alternative treatment option. In light of the failure of many pharmaceuticals to curb noncommunicable diseases, these results are deemed of high importance.
The pharmaceutical industry is in need of rapid and accurate methods to screen new drug leads for... more The pharmaceutical industry is in need of rapid and accurate methods to screen new drug leads for intestinal permeability potential in the early stages of drug discovery. Excised human jejunal mucosa was used to investigate the permeability of the small intestine to four oral drugs, using a flow-through diffusion system. The four drugs were selected as representative model compounds of drug classes 1 and 3 according to the biopharmaceutics classification system (BCS). The drugs selected were zidovudine, propranolol HCl, didanosine, and enalapril maleate. Permeability values from our in vitro diffusion model were compared with the BCS permeability classification and in vivo and in vitro gastrointestinal drug permeability. The flux rates of the four drugs were influenced by the length of the experiment. Both class 1 drugs showed a significantly higher mean flux rate between 2 and 6 h across the jejunal mucosa compared to the class 3 drugs. The results are therefore in line with the drugs' BCS classification. The results of this study show that the permeability values of jejunal mucosa obtained with the flow-through diffusion system are good predictors of the selected BCS class 1 and 3 drugs' permeation, and it concurred with other in vitro and in vivo studies.
Induction of interleukin-6 (IL-6) secretion by whole blood cultures (WBC) was used as an in vitro... more Induction of interleukin-6 (IL-6) secretion by whole blood cultures (WBC) was used as an in vitro assay system for pyrogen-induced inflammatory reactions. The assay system was very sensitive to Eschericia coli (E.coli) endotoxin (< 10 pg/ml). The potential pyrogenic effects of human serum albumin (HSA), Fibronectin (Fn) and stabilised human serum (SHS) solutions were analyzed using this system. None of
South African journal of physiotherapy, Feb 18, 2007
Introduction: Music, processed by the brain, has a strong impact on the emotions and health. The ... more Introduction: Music, processed by the brain, has a strong impact on the emotions and health. The Magnificat in D major of JS Bach communicates not only a positive emotion of happiness but also motivational behaviour. Infectious lung conditions are often associated with negative emotions which develop due to physiological changes. The hormonal action of the hypothalamuspituitary-adrenal axes (HPA) could be negatively affected by emotions of anger and depression. This will result in a disturbance of the mind-body interaction. Music therefore can exert a powerful influence on therapeutic benefits by changing the psychological status and the immune endocrine functions. The purpose of this study was to determine the effect of music, during respiratory physiotherapy treatment on a) the emotional status, b) neuroendocrine responses, c) immune functions and d) lung functions of subjects with infected lung conditions. Method and Materials: Forty subjects attending physiotherapy treatment was selected according to set criteria and randomly assigned to an experimental and control group. The parameters (Profile Of Mood State [POMS]; CD4: CD8 cell ratios; Cortisol; the Cortisol: DHEA ratio; PF; FEV1; FVC and FEV1/FVC %) were measured on day 1 before the treatment and on day 3 after the treatment. Data were analysed with Statistica (Statsoft) using the Repeated ANOVA tests. Results: Results indicated that the intervention of music had a positive effect on the immunological parameter (CD4+:CD8+ cell ratios) and on the cortisol and cortisol:DHEA ratio levels. At the same time the psychological status as measured by Profile of Mood States (POMS scale) improved with a significant improvement in the lung functions. Conclusion: The research provided sufficient scientific evidence that music affects both the biomedical and psychosomatic aspects of infectious lung conditions.
Current Opinion in Clinical Nutrition and Metabolic Care, Nov 1, 2001
Although plant sterols (phytosterols) were chemically described in 1922, their biological role in... more Although plant sterols (phytosterols) were chemically described in 1922, their biological role in human and animal health has been underestimated. Their ability to control cholesterol plasma levels in hypercholesterolimic patients was first described in 1983 when the structure of phytosterols implied that they could, by steric hindrance, inhibit the absorption of cholesterol from our diets. This has led to the development of functional foods containing high contents of these plant molecules or their esters as cholesterol controlling foods. Over the last 15 years, however, several reports have appeared in the literature indicating that phytosterols have some immunological activity as highlighted in animal models of inflammation or even in in-vitro and in-vivo models of cancer (colorectal and breast cancer). These findings were paralleled by epidemiological studies correlating the reduced risk of numerous diseases and the dietary intake of phytosterols. It is only in the last 10 years, however, that their direct immune modulatory activity on human lymphocytes has been proven and the mechanism of action in cancer cells has been elucidated. The use of phytosterols as supportive therapies in certain chronic conditions has been tested under clinical trial conditions. This review presents a summary of the in-vitro and in-vivo studies published to date.
African Journal of Traditional, Complementary and Alternative Medicines, Aug 12, 2014
Background: Studies have suggested an increasing practice of concurrent herb-drug consumption. On... more Background: Studies have suggested an increasing practice of concurrent herb-drug consumption. One of the major clinical risks of such concomitant herb-drug use is pharmacokinetic herb-drug interaction (HDI). This is brought about by the ability of phytochemicals to inhibit or induce the activity of metabolic enzymes. The aim of this study was to investigate the potential of the crude aqueous extracts of three popular medicinal herbs used in South Africa to inhibit major cytochrome P450 (CYP) enzymes. Materials and Methods: The extracts of Bowiea volubilis, Spirostachys africana and Tulbaghia violacea were incubated with human liver microsomes (HLM) to monitor the phenacetin O-deethylation, diclofenac 4'-hydroxylation, S-mephenytoin 4'-hydroxylation and testosterone 6βhydroxylation as respective probe reactions for CYP1A2, CYP2C9, CYP2C19 and CYP3A4. The inhibitory activity, where observed, was profiled against the extract concentration. Results: Extracts of Bowiea volubilis inhibited the metabolic activity of CYP1A2 and CYP3A4 with IC 50 values of 92.3 ± 5.5 g/mL and 8.1 ± 0.6 g/mL respectively. Similar observation with Spirostachys africana showed inhibitory activity against CYP1A2 and CYP3A4 with respective IC 50 values of 14.3 ± 0.6 g/mL and 47.4 ± 2.4 g/mL. Tulbaghia violacea demonstrated relatively weak inhibitory activity against CYP1A2 (767.4 ± 10.8 g/mL) and CYP2C9 (921 ± 15.3 g/mL). Conclusion: The results suggest the potential for HDI between the herbs and the substrates of the affected enzymes, if sufficient in vivo concentration is attained.
Context: Aqueous decoction of Hypoxis hemerocallidea Fisch. & C.A. Mey. (Hypoxidaceae) (Hypoxis) ... more Context: Aqueous decoction of Hypoxis hemerocallidea Fisch. & C.A. Mey. (Hypoxidaceae) (Hypoxis) is widely consumed in Southern Africa by people living with HIV/AIDS, some of whom are on ARV and other medications. Objective: The aim of this study was to investigate the potential of the crude aqueous extracts of Hypoxis to inhibit major forms of CYP450 and transport proteins. Materials and methods: Corms of Hypoxis were water-extracted and incubated (in graded concentrations: 1-100 mg/mL) with human liver microsomes (20 min) to monitor the effects on phenacetin O-deethylation, coumarin 7-hydroxylation, bupropion hydroxylation, paclitaxel 6a-hydroxylation, diclofenac 4 0-hydroxylation, S-mephenytoin 4 0-hydroxylation, bufuralol 1 0-hydroxylation, chlorzoxazone 6-hydroxylation, midazolam 1 0-hydroxylation and testosterone 6b-hydroxylation as markers for the metabolic activities of CYP1A2, 2A6, 2B6, 2C8, 2C9, 2C19, 2D6, 2E1 and 3A4/5, respectively. The generation of metabolites were monitored and quantified with the aid of LC-MS/MS. The potential of the extracts to inhibit human ATPbinding cassette transporter activity was assessed using recombinant MDCKII and LLC-PK1 cells over-expressing human breast cancer resistant protein and human P-glycoprotein , respectively (with Ko143 and cyclosporin A as positive controls). Similar assessment was performed with human organic anion transporting polypeptide (OATP1B1 and OATP1B3) using recombinant HEK293 cells over-expressing OATP1B1 and OATP1B3, respectively (with rifamycin and 10 mM atorvastatin as positive controls). Results: Extracts of Hypoxis inhibited the production of the metabolites of the substrates of the following enzymes (as compared to controls) with the indicated IC 50 values (mg/mL): CYP1A2 (120.6), CYP2A6 (210.8), CYP2B6 (98.5), CYP2C8 (195.2), CYP2C9 (156) and CYP3A4/5 (185.4). The inhibition of the uptake activity of OATP1B1 and OATP1B3 were also observed with IC 50 values of 93.4 and 244.8 mg/mL, respectively. Discussion: Extract concentrations higher than the estimated IC 50 values are achievable in the gastrointestinal tract when traditional doses of Hypoxis are considered. This may have profound effects on presystemic metabolism of the drug substrates. If absorbed, systemic inhibition of metabolic enzymes/transporters by Hypoxis may be expected. Conclusion: The result suggests that there is the potential for HDI between Hypoxis and the substrates of the affected enzymes/transporters, if sufficient in vivo concentration of Hypoxis extracts is attained.
a,-Microglobulin (a Im), a glycoprotein heterogeneous in charge, was reported to occur both as a ... more a,-Microglobulin (a Im), a glycoprotein heterogeneous in charge, was reported to occur both as a 31-kilodalton (kd) monomer [low mol. wt a: Im (LMW-a Im)] and as polymers or complexes formed with other plasma proteins including IgA [high mol. wt a: Im (HMW-a lm)]. The present study was designed to characterize HMW-a Im in normal human serum and in myeloma sera. The following sera were selected: five IgG, 16 IgA and four Bence-Jones protein myelomas. a lm was identified by specific monoclonal antibodies in competitive radioimmunoassay and solid-phase ELISA. HMW-c(lm was found to be associated almost exclusively with monomeric IgA and possibly in very small proportion with dimeric IgA. Ever, in cases of predominantly dimeric IgA myelomas, alm was associated with the monomeric form of the monoclonal IgA. The molar ratio of HMW-a Im to monomeric IgA never exceeded 3.5% and it was estimated to range from 0.5 to 1.4% in normal serum. No association with other proteins than IgA and no a lm polymers were found in IgA myeloma. Two types of HMW-a Im-IgA complexes were found: (a) those that were dissociable into IgA and LMW-a Im after mild reduction, and (b) those which were dissociated only after complete reduction of the complexes into IgA and an 88-90-kd component bearing c(Im but no IgA epitopes. It was concluded that either of the two molecular species of a Im bearing common epitopes, with apparent mol. wts of 31,000 and 88,000-90,000, respectively, could form stable complexes with monomeric IgA. The association is likely to be performed through disulfide bridges. Nearly all the 88-90-kd but only a small proportion of the 31-kd component is associated with IgA.
Sutherlandia frutescens (ST) is a popular medicinal herb widely consumed in Africa by people livi... more Sutherlandia frutescens (ST) is a popular medicinal herb widely consumed in Africa by people living with HIV/AIDS. Concomitant use with antiretroviral drugs has generated concerns of herb-drug interaction. This study investigated the inhibitory effects of the crude extracts of ST on the major cytochrome P450 isozymes employing pooled human liver microsomes. Its effect on the metabolic clearance of midazolam using cryopreserved hepatocytes was also monitored. The potential of ST to inhibit human ATP-binding cassette (ABC) transporters (P-gp and BCRP) and the human organic anion transporting polypeptide (OATP1B1 and OATP1B3) activity was assessed using cell lines overexpressing the transporter proteins. ST showed inhibitory potency for CYP1A2 (IC 50 = 41.0 µg/mL), CYP2A6 (IC 50 = 160 µg/mL), CYP2B6 (IC 50 = 20.0 µg/mL), CYP2C8 (IC 50 = 22.4 µg/mL), CYP2C9 (IC 50 = 23.0 µg/mL), CYP2C19 (IC 50 = 35.9 µg/mL) and CYP3A4/5 (IC 50 = 17.5 µg/mL [with midazolam1'-hydroxylation]; IC 50 = 28.3 µg/mL [with testosterone 6β-hydroxylation]). Timedependent (irreversible) inhibition by ST was observed for CYP3A4/5 (KI = 296 µg/mL, kinact = 0.063 min-1) under the conditions of this study. ST also delays the production of midazolam metabolites in the hepatocytes, decreasing its clearance by 40%. Further, ST inhibited P-gp (IC 50 = 324.8 µg/mL); OATP1B1 (IC 50 = 10.4 µg/mL, and of OATP1B3 (IC 50 = 6.6 µg/mL). The result indicates the potential for HDI between ST and the substrates of the affected enzymes, if sufficient in vivo concentration of ST is attained.
1. This study investigated the mechanism underlying Echinacea-mediated induction of CYP1A2, CYP3A... more 1. This study investigated the mechanism underlying Echinacea-mediated induction of CYP1A2, CYP3A4 and MDR1 in terms of human pregnane X receptor (PXR) activation. 2. Crude extracts and fractions of Echinacea purpurea were tested for PXR activation in HepG2 cells by a reporter gene assay. Quantitative real-time PCR was carried out to determine their effects on CYP1A2 and CYP3A4 mRNA expressions. Capsules and fractions were risk ranked as high, intermediate and remote risk of drug-metabolizing enzymes induction based on EC 50 values determined for respective CYPs. 3. Fractions F 1 , F 2 and capsule (2660) strongly activated PXR with 5-, 4-and 3.5-fold increase in activity, respectively. Echinacea preparations potentiated up-regulation of CYP1A2, CYP3A4 and MDR1 via PXR activation. 4. Thus E. purpurea preparations cause herb-drug interaction by up-regulating CYP1A2, CYP3A4 and P-gp via PXR activation.
Journal of Histochemistry and Cytochemistry, Jul 1, 1984
The tissue distribution of rat a,-microglobulin (a1-m) was studied by indirect immunofluorescence... more The tissue distribution of rat a,-microglobulin (a1-m) was studied by indirect immunofluorescence in various rat tissues using a polyvalent rabbit antiserum to the purified antigen and a monoclonal antibody (H23) to the human homologue, in parallel with a polyclonal anti-rat IgA antiserum. It was found that all tissues stained by anti-IgA were also a1-m positive; these tissues included tissues of the stomach, duodenum, ileum, colon, pancreas, trachea, esophagus and jejunum. However, the observation that IgA plasma cells as well as secretory cells, while positively stained by anti-IgA, are a1-m negative suggests that the association between IgA and a1-m occurs at a postsecretory stage, after the IgA molecules have been transported across the epithelial cells. Additionally, hepatocytes were intensely stained by anti-a1-m antibodies, indicating that the liver, as already suggested by metabolic studies on isolated guinea-pig liver explants, may be responsible for the synthesis of this protein. Among lymphoid tissues, an intense and homogeneous staining was observed in the thymus and the white pulp of the spleen. Sections of lymph nodes, might help to resolve the discrepancies among the reports on human a1-m. So far, however, only guinea-pig a1-m has been characterized, by Akerstr#{246}m and Berggard (2). These authors
Calcium-dependent natural killer and calcium-independent natural cytotoxic activities in an IL-2-... more Calcium-dependent natural killer and calcium-independent natural cytotoxic activities in an IL-2-dependent killer cell line.
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