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The objective of this study was to elucidate the proteomic mechanisms of drug resistance in HIV-infected African patients. Cell membrane fractions from forty oral Candida isolates isolated from African HIV-positive patients were analysed using HPLC-MS with the aim of identifying proteins associated with their pathogenicity and drug resistance. Heat shock proteins that mediate the fungicidal activity of salivary peptides were found in all tested Candida fractions, with pH-responsive proteins associated with increased pathogenicity only being present in the three most commonly isolated species. ABC multidrug transporter efflux pumps and estrogen binding proteins were only found in C. albicans fractions, while ergosterol biosynthesis proteins were identified in four species. The combination of various adherence, invasion, upregulation and efflux pump mechanisms appear to be instrumental for the Candida host colonization and drug resistance emergence in HIV-infected individuals.
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Aim: Serological assays for the detection of anti-SARS coronavirus-2 (SARS-CoV-2) antibodies are essential to the response to the global pandemic. A ligand binding-based serological assay was validated for the semiquantitative detection of IgG, IgM, IgA and neutralizing antibodies (nAb) against SARS-CoV-2 in serum. Results: The assay demonstrated high levels of diagnostic specificity and sensitivity (85-99% for all analytes). Serum IgG, IgM, IgA and nAb correlated positively (R2 = 0.937, R2 = 0.839, R2 = 0.939 and R2 = 0.501, p < 0.001, respectively) with those measured in dried blood spot samples collected using the hemaPEN® microsampling device (Trajan Scientific and Medical, Victoria, Australia). In vitro SARS-CoV-2 pseudotype neutralization correlated positively with the solid phase nAb signals in convalescent donors (R2 = 0.458, p < 0.05). Conclusion: The assay is applicable in efficacy studies, infection monitoring and postmarketing surveillance following vaccine rollout.
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COVID-19/sangue , Teste em Amostras de Sangue Seco/métodos , Ensaios de Triagem em Larga Escala/métodos , SARS-CoV-2/patogenicidade , Bioensaio , Voluntários Saudáveis , Humanos , Reprodutibilidade dos TestesRESUMO
ETHNOPHARMACOLOGICAL RELEVANCE: Withania somnifera (L.) Dunal (Solanaceae) is a traditional herb, used in African indigenous systems of medicine for the treatment of various diseases (including HIV/AIDS and tuberculosis). The relevance of clinically significant interactions of Withania with ARVs and anti-TB drugs needs to be investigated. AIM OF THE STUDY: This study evaluated the effects of its roots on cytochromes P450 (CYPs) 2B6, 3A4, and rifampicin metabolism pathway, using methanol, ethanol, aqueous, and ethyl acetate solvent extractions. MATERIALS AND METHODS: The extracts were tested on human liver microsomes (HLM) for CYP inhibition, mRNA expression in HepG2 cells for CYP induction. Biochemical qualitative tests and LC-MS/MS methodology were used to determine active phytoconstituents. RESULTS: The methanolic and ethyl acetate extracts inhibited CYP2B6 with IC50s 79.16 and 57.96 µg/ml respectively, while none of the extracts had any effect on rifampicin metabolism or showed time-dependant inhibition (TDI). All extracts were moderate inducers of CYP3A4; the aqueous extract exhibited 38%-fold shift induction of CYP3A4 compared to the control. The methanolic extract had the lowest CTC50 (50% of cytotoxicity inhibition) (67.13 ± 0.83 µg/ml). LC-MS/MS-PDA full scans were consistent with the presence of flavone salvigenin (m/z 327), alkaloid isopelletierine (m/z 133), steroidal lactone 2,3-dihydrowithaferin-A (m/z 472), and other withanolides including withaperuvin I (m/z 533), withaferin derivative (m/z 567), some of these compounds likely being responsible for the observed CYP2B6 inhibition and CYP3A4 induction. The putative gastrointestinal tract (GIT) concentration for the active extracts was 1800 µg/ml and the hepatic circulation concentrations were estimated at about 220 µg/ml and 13.5 µg/ml for the methanolic and ethyl acetate extracts, respectively. The extrapolated in vivo percentage of inhibition was at 85% for the methanolic extract against CYP2B6. CONCLUSIONS: The findings reported in this study suggest that W. somnifera extracts have the potential of causing clinically significant herb-drug interactions (HDI) as moderate inducer of CYP3A4 and inhibitor of CYP2B6 metabolism pathway (methanol and ethyl acetate extracts).
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Citocromo P-450 CYP2B6/metabolismo , Citocromo P-450 CYP3A/metabolismo , Esterases/metabolismo , Microssomos Hepáticos/enzimologia , Extratos Vegetais/farmacologia , Withania/química , Citocromo P-450 CYP2B6/genética , Inibidores do Citocromo P-450 CYP2B6/farmacologia , Citocromo P-450 CYP3A/genética , Indutores do Citocromo P-450 CYP3A/farmacologia , Células Hep G2 , Interações Ervas-Drogas , Humanos , Concentração Inibidora 50 , Medicinas Tradicionais Africanas , Microssomos Hepáticos/efeitos dos fármacos , Raízes de Plantas/química , Plantas Medicinais/química , Rifampina/metabolismoRESUMO
Ocimum basilicum L. or basilicum is a common culinary herb, used as a traditional medicine for various medical conditions including HIV/AIDS and tuberculosis, in Africa. The objective of this study was to evaluate the effect of methanol, ethanol, aqueous and ethyl acetate extracts of the dried leaves and inflorescence of O. basilicum, on the activity of cytochrome P450 enzymes (CYPs) CYP2B6 and 3A4, as well as esterase-mediated metabolism of rifampicin to 25-O-desacetyl rifampicin (25ODESRIF). Human liver microsomes (HLM) were used to evaluate inhibition and CYP2B6/3A4 mRNA expression HepG2 assays were used to measure induction. Furthermore, the phytoconstituents likely involved in causing the observed effect were analyzed using biochemical tests and LC-MS. The aqueous and methanolic extracts showed reversible and time-dependent inhibition (TDI) of CYP2B6 with TDI-IC50s 33.35 µg/ml (IC50 shift-fold >1.5) and 4.93 µg/ml (IC50 shift-fold >7) respectively, while the methanolic and ethanolic extracts inhibited 25ODESRIF formation (IC50s 31 µg/ml, 8.94 µg/ml). In HepG2 assays, the methanolic and ethanolic extracts moderately induced CYP2B6, 3A4 mRNA with 38%-, 28%-fold shift, and 22%-, 44%-fold shift respectively. LC-MS full scans identified phenols rosmarinic acid [m/z 359 (M-H)-, approximately 2298 mg/L in aqueous extract] and caftaric acid along with flavones salvigenin [m/z 329 (M+H)+, approximately 1855 mg/L in ethanolic extract], eupatorin [m/z 345 (M+H)+, 668.772 mg/L in ethanolic extract], rutin [m/z 609 (M-H)-] and isoquercetin [m/z 463 (M-H)-] and other compounds-linalool [m/z 153 (M-H)-], hydroxyjasmonic acid [m/z 225 (M-H)-], eucommiol [m/z 187 (M-H)-] and trihydroxy octadecenoic acid [m/z 329 (M-H)-, 530 mg/L in ethanolic extract]. The putative gastrointestinal tract (GIT) concentration for all extracts was calculated as 2,400 µg/ml and hepatic circulation concentrations were estimated at 805.68 µg/ml for the aqueous extract, and 226.56 µg/ml for methanolic extract. Based on the putative GIT concentration, estimated hepatic circulation concentration [I] and inhibition constant Ki, the predicted percentile of inhibition in vivo was highest for the aqueous extract on CYP2B6 (96.7%). The observations indicated that O. basilicum extracts may have the potential to cause clinically relevant herb-drug interactions (HDI) with CYP2B6 and rifampicin metabolism in vivo, if sufficient hepatic concentrations are reached in humans.
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PROBLEM: The impact of metabolic syndrome (MetS) associated systemic inflammation on the male reproductive tract requires further investigation. METHOD OF STUDY: A cross-sectional case-controlled study design consisting of a control group (n=32) and a MetS (n=42) group was used. Variables include MetS diagnostic criterion, serum C-Reactive Protein (CRP), routine semen analysis, spermatozoa mitochondrial membrane potential (MMP) and DNA fragmentation (DF), as well as TNF-α, IL-1ß, IL6 and IL8 concentrations in serum and semen. RESULTS: Serum and seminal levels of TNF-α, IL-1ß, IL6 and IL8 were all significantly increased in the MetS group. Ejaculation volume, sperm concentration, total sperm count, progressive and total motility and vitality were significantly decreased and sperm with abnormal MMP and DF were increased in the MetS group. CONCLUSION: The results suggest that MetS is associated with decreased fertility parameters in males, as well as local reproductive tract inflammation, in the absence of leukocytospermia.
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Proteína C-Reativa/imunologia , Citocinas/imunologia , Fertilidade/imunologia , Síndrome Metabólica/imunologia , Sêmen/imunologia , Adulto , Idoso , Estudos de Casos e Controles , Fragmentação do DNA , Humanos , Masculino , Potencial da Membrana Mitocondrial/imunologia , Pessoa de Meia-Idade , Contagem de Espermatozoides , Espermatozoides/imunologiaRESUMO
Kalanchoe crenata popularly known as "dog's liver" is used in most African countries for the treatment of chronic diseases such as diabetes, asthma and HIV/AIDS related infections. The evaluation of K. crenata for herb-drug interactions has not been reported. This study therefore aims to evaluate the risk of K. crenata for herb-drug interaction in vitro. Crude methanol and fractions of K. crenata were incubated and preincubated with recombinant human CYP2C19 and CYP3A4. Comparative studies were conducted in both human liver microsomes and recombinant human CYP to ascertain the inhibition profile of the crude extract and the various fractions. The cocktail approach of recombinant human CYPs was conducted to confirm the inhibition potential of the fractions in the presence of other CYPs. The results showed significant time-dependent inhibition of tested samples on CYP3A4 with crude methanol (39KC), fractions 45A, 45B and 45D given IC50 fold decrease of 3.29, 2.26, 1.91 and 1.49, respective. Time dependent kinetic assessment of 39KC and 45D showed KI and kinact values for 39KC as 1.77 µg/mL and 0.091 min(-1) while that of 45D were 6.45 µg/mL and 0.024 min(-1), respectively. Determination of kinact based on IC50 calculations yielded 0.015 and 0.04 min(-1) for 39KC and 45D, respectively. Cocktail approach exhibited fold decreases in IC50 for all test fractions on CYP3A4 within the ranges of 2.10 - 4.10. At least one phytoconstituent in the crude methanol extract of Kalanchoe crenata is a reversible and time-dependent inhibitor of CYP3A4.
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Inibidores do Citocromo P-450 CYP2C19/farmacologia , Citocromo P-450 CYP2C19/metabolismo , Inibidores do Citocromo P-450 CYP3A/farmacologia , Citocromo P-450 CYP3A/metabolismo , Kalanchoe , Fígado/efeitos dos fármacos , Extratos Vegetais/farmacologia , Inibidores do Citocromo P-450 CYP2C19/isolamento & purificação , Inibidores do Citocromo P-450 CYP3A/isolamento & purificação , Relação Dose-Resposta a Droga , Hepatócitos/efeitos dos fármacos , Hepatócitos/enzimologia , Interações Ervas-Drogas , Humanos , Kalanchoe/química , Cinética , Fígado/enzimologia , Metanol/química , Microssomos Hepáticos/enzimologia , Modelos Biológicos , NADP/metabolismo , Extratos Vegetais/isolamento & purificação , Proteínas Recombinantes/metabolismo , Medição de Risco , Solventes/química , Testosterona/metabolismoRESUMO
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 EC50 values determined for respective CYPs. 3. Fractions F1, F2 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.
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Membro 1 da Subfamília B de Cassetes de Ligação de ATP/genética , Citocromo P-450 CYP1A2/genética , Citocromo P-450 CYP3A/genética , Echinacea/química , Extratos Vegetais/farmacologia , Receptores de Esteroides/metabolismo , Regulação para Cima/efeitos dos fármacos , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/metabolismo , Biocatálise/efeitos dos fármacos , Morte Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Citocromo P-450 CYP1A2/metabolismo , Citocromo P-450 CYP3A/metabolismo , Genes Reporter , Células Hep G2 , Interações Ervas-Drogas , Humanos , Luciferases/metabolismo , Receptor de Pregnano X , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Fatores de Tempo , Ativação Transcricional/efeitos dos fármacos , Ativação Transcricional/genéticaRESUMO
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 6ß-hydroxylation 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 IC50 values of 92.3 ± 5.5 µg/mL and 8.1 ± 0.6 µg/mL respectively. Similar observation with Spirostachys africana showed inhibitory activity against CYP1A2 and CYP3A4 with respective IC50 values of 14.3 ± 0.6 µg/mL and 47.4 ± 2.4 µg/mL. Tulbaghia violacea demonstrated relatively weak inhibitory activity against CYP1A2 (767.4 ± 10.8 µg/mL) and CYP2C9 (921 ± 15.3 µg/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.
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Citocromo P-450 CYP1A2/metabolismo , Citocromo P-450 CYP2C9/metabolismo , Citocromo P-450 CYP3A/metabolismo , Interações Ervas-Drogas , Preparações Farmacêuticas/metabolismo , Extratos Vegetais/farmacologia , Plantas Medicinais , Citocromo P-450 CYP2C19/metabolismo , Diclofenaco/metabolismo , Euphorbiaceae , Humanos , Hidroxilação , Liliaceae , Magnoliopsida , Mefenitoína/metabolismo , Microssomos Hepáticos/efeitos dos fármacos , Microssomos Hepáticos/metabolismo , Fenacetina/metabolismo , África do Sul , Testosterona/metabolismoRESUMO
BACKGROUND: Obesity appears to be associated with male reproductive dysfunction and infertility, although this has been inconsistent and inconclusive. Insulin and leptin are known mediators and modulators of the hypothalamus-pituitary-testes axis, contributing to the regulation of male reproductive potential and overall wellbeing. These hormones are also present in semen influencing sperm functions. Although abdominal obesity is closely associated with insulin resistance (hyperinsulinaemia), hyperleptinaemia and glucose dysfunction, changes in seminal plasma concentrations of insulin, leptin and glucose in obese males has not previously been investigated. METHODS: This small case controlled study assessed serum and seminal concentrations of insulin, leptin and glucose in obese (BMI > =30; n = 23) and non-obese (BMI < 30; n = 19) males. Following a detailed medical history and examination, participants meeting the inclusion criteria were entered for data analysis. Body parameters such as BMI, waist and hip circumference and the waist hip ratio were measured. Serum and semen samples were collected and assayed for insulin, leptin and glucose. Semen samples also underwent a standard semen analysis, with sperm mitochondrial membrane potential (MMP) and DNA fragmentation (DF). RESULTS: Obesity was associated with increased serum and seminal insulin and leptin, with no significant difference in seminal glucose. Serum and seminal concentrations of insulin and leptin were positively correlated. Furthermore, obesity was associated with decreased sperm concentration, sperm vitality and increased MMP and DF, with a non-significant impact on motility and morphology. CONCLUSIONS: Hyperinsulinaemia and hyperleptinaemia are associated with increased seminal insulin and leptin concentrations, which may negatively impact male reproductive function in obesity. Insulin was also found to be highly concentrated in the seminal plasma of both groups. This data will contribute to the contradictive information available in the literature on the impact of obesity and male reproduction.
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Infertilidade Masculina/etiologia , Insulina/metabolismo , Leptina/metabolismo , Obesidade/fisiopatologia , Sêmen/metabolismo , Regulação para Cima , Adulto , Índice de Massa Corporal , Estudos de Casos e Controles , Estudos de Coortes , Fragmentação do DNA , Humanos , Hiperinsulinismo/etiologia , Insulina/sangue , Leptina/sangue , Masculino , Potencial da Membrana Mitocondrial , Pessoa de Meia-Idade , Obesidade/sangue , Obesidade/metabolismo , Projetos Piloto , Análise do Sêmen , África do Sul , Adulto JovemRESUMO
The purpose of this study was to evaluate the potential risk of common herbal medicines used by HIV-infected patients in Africa for herb-drug interactions (HDI). High throughput screening assays consisting of recombinant Cytochrome P450 enzymes (CYPs) and fluorescent probes, and parallel artificial membrane permeability assays (PAMPA) were used. The potential of herbal medicines to cause HDI was ranked according to FDA guidelines for reversible inhibition and categorization of time dependent inhibition was based on the normalized ratio. CYPs 1A2 and 3A4 were most inhibited by the herbal extracts. H. hemerocallidea (IC50 = 0.63 µg/mL and 58 µg/mL) and E. purpurea (IC50 = 20 µg/mL and 12 µg/mL) were the potent inhibitors of CYPs 1A2 and 3A4 respectively. L. frutescens and H. hemerocallidea showed clear time dependent inhibition on CYP3A4. Furthermore, the inhibitory effect of both H. hemerocallidea and L. frutescens before and after PAMPA were identical. The results indicate potential HDI of H. hemerocallidea, L. frutescens and E. purpurea with substrates of the affected enzymes if maximum in vivo concentration is achieved.
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Fármacos Anti-HIV/efeitos adversos , Inibidores das Enzimas do Citocromo P-450/efeitos adversos , Sistema Enzimático do Citocromo P-450/metabolismo , Infecções por HIV/tratamento farmacológico , Interações Ervas-Drogas , Preparações de Plantas/efeitos adversos , África , Relação Dose-Resposta a Droga , Infecções por HIV/diagnóstico , Ensaios de Triagem em Larga Escala , Humanos , Isoenzimas , Fitoterapia , Plantas Medicinais , Proteínas Recombinantes/metabolismo , Medição de Risco , Fatores de Risco , Especificidade por SubstratoRESUMO
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 µg/mL) with human liver microsomes (20 min) to monitor the effects on phenacetin O-deethylation, coumarin 7-hydroxylation, bupropion hydroxylation, paclitaxel 6α-hydroxylation, diclofenac 4'-hydroxylation, S-mephenytoin 4'-hydroxylation, bufuralol 1'-hydroxylation, chlorzoxazone 6-hydroxylation, midazolam 1'-hydroxylation and testosterone 6ß-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 ATP-binding 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 µM 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 IC50 values (µg/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 IC50 values of 93.4 and 244.8 µg/mL, respectively. DISCUSSION: Extract concentrations higher than the estimated IC50 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.
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Interações Ervas-Drogas , Hypoxis/química , Microssomos Hepáticos/efeitos dos fármacos , Preparações Farmacêuticas , Extratos Vegetais/farmacologia , Transportadores de Cassetes de Ligação de ATP/antagonistas & inibidores , Animais , Inibidores das Enzimas do Citocromo P-450 , Cães , Células HEK293 , Humanos , Técnicas In Vitro , Células LLC-PK1 , Células Madin Darby de Rim Canino , Medicinas Tradicionais Africanas , Microssomos Hepáticos/enzimologia , Extratos Vegetais/isolamento & purificação , Especificidade por Substrato , SuínosRESUMO
In Africa, Sutherlandia frutescens is a popular medicinal herb widely consumed by people living with human immunodeficiency virus/AIDS. Concomitant use with antiretroviral drugs has generated concerns of herb-drug interaction (HDI). This study investigated the inhibitory effects of the crude extracts of S. frutescens on the major cytochrome P450 isozymes with the use of pooled human liver microsomes. Its effect on the metabolic clearance of midazolam using cryopreserved hepatocytes was also monitored. The potential of S. frutescens to inhibit human ATP-binding cassette 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. S. frutescens 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 6ß-hydroxylation]). Time-dependent (irreversible) inhibition by S. frutescens was observed for CYP3A4/5 (K(I) = 296 µg/ml, k(inact) = 0.063 min(-1)) under the conditions of this study. S. frutescens also delays the production of midazolam metabolites in the hepatocytes, decreasing its clearance by 40%. Furthermore, S. frutescens inhibited P-gp (IC(50) = 324.8 µg/ml), OATP1B1 (IC(50) = 10.4 µg/ml), and OATP1B3 (IC(50) = 6.6 µg/ml). The result indicates the potential for HDI between S. frutescens and the substrates of the affected enzymes, if sufficient in vivo concentration of the extract is attained.
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Inibidores das Enzimas do Citocromo P-450 , Inibidores Enzimáticos/farmacologia , Fabaceae/química , Hepatócitos/efeitos dos fármacos , Interações Ervas-Drogas , Moduladores de Transporte de Membrana/farmacologia , Proteínas de Membrana Transportadoras/efeitos dos fármacos , Preparações de Plantas/farmacologia , Subfamília B de Transportador de Cassetes de Ligação de ATP , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/antagonistas & inibidores , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/metabolismo , Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP , Transportadores de Cassetes de Ligação de ATP/antagonistas & inibidores , Transportadores de Cassetes de Ligação de ATP/metabolismo , Animais , Transporte Biológico , Biotransformação , Sistema Enzimático do Citocromo P-450/metabolismo , Cães , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/isolamento & purificação , Feminino , Células HEK293 , Hepatócitos/enzimologia , Humanos , Hidroxilação , Isoenzimas , Cinética , Células LLC-PK1 , Transportador 1 de Ânion Orgânico Específico do Fígado , Células Madin Darby de Rim Canino , Masculino , Moduladores de Transporte de Membrana/isolamento & purificação , Proteínas de Membrana Transportadoras/genética , Proteínas de Membrana Transportadoras/metabolismo , Microssomos Hepáticos/efeitos dos fármacos , Microssomos Hepáticos/enzimologia , Midazolam/metabolismo , Proteínas de Neoplasias/antagonistas & inibidores , Proteínas de Neoplasias/metabolismo , Transportadores de Ânions Orgânicos/antagonistas & inibidores , Transportadores de Ânions Orgânicos/metabolismo , Transportadores de Ânions Orgânicos Sódio-Independentes/antagonistas & inibidores , Transportadores de Ânions Orgânicos Sódio-Independentes/metabolismo , Folhas de Planta , Preparações de Plantas/isolamento & purificação , Plantas Medicinais , Membro 1B3 da Família de Transportadores de Ânion Orgânico Carreador de Soluto , Especificidade por Substrato , Suínos , Testosterona/metabolismo , TransfecçãoRESUMO
Despite the lack of sufficient information on the safety of herbal products, their use as alternative and/or complementary medicine is globally popular. There is also an increasing interest in medicinal herbs as precursor for pharmacological actives. Of serious concern is the concurrent consumption of herbal products and conventional drugs. Herb-drug interaction (HDI) is the single most important clinical consequence of this practice. Using a structured assessment procedure, the evidence of HDI presents with varying degree of clinical significance. While the potential for HDI for a number of herbal products is inferred from non-human studies, certain HDIs are well established through human studies and documented case reports. Various mechanisms of pharmacokinetic HDI have been identified and include the alteration in the gastrointestinal functions with consequent effects on drug absorption; induction and inhibition of metabolic enzymes and transport proteins; and alteration of renal excretion of drugs and their metabolites. Due to the intrinsic pharmacologic properties of phytochemicals, pharmacodynamic HDIs are also known to occur. The effects could be synergistic, additive, and/or antagonistic. Poor reporting on the part of patients and the inability to promptly identify HDI by health providers are identified as major factors limiting the extensive compilation of clinically relevant HDIs. A general overview and the significance of pharmacokinetic and pharmacodynamic HDI are provided, detailing basic mechanism, and nature of evidence available. An increased level of awareness of HDI is necessary among health professionals and drug discovery scientists. With the increasing number of plant-sourced pharmacological actives, the potential for HDI should always be assessed in the non-clinical safety assessment phase of drug development process. More clinically relevant research is also required in this area as current information on HDI is insufficient for clinical applications.
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Early understanding of the metabolic pathway and potential interaction of new drug candidates with other drugs is one of the goals of preclinical studies in the drug discovery process. Although other body organs are involved in drug biotransformation, the liver is the predominant organ of metabolism for a wide range of endogenous compounds and xenobiotics. The set of enzymes contained in the cytochrome P450 superfamily present predominantly in the liver have been identified as the single most important agent of drug metabolism and have formed the bedrock of most matured technologies for in vitro drug biotransformation studies. With the development of a number of liver-based technologies, in vitro metabolism has gained significant popularity in the past three decades. This has come in response to several demanding factors including the questionable relevance of data from animal studies; the high cost and stringent regulatory and ethical requirement, as well as safety issues involved with studies using human subjects; and the need for high throughput due to the wide range of chemical entities for routine investigations. These technologies which vary from whole liver to subcellular fractions have found ready application in generating the desired information on the substrate and inhibitor specificity of most metabolic enzymes. This paper reviews such technologies as isolated fresh liver; liver slices; primary, cultured and cryopreserved hepatocytes; microsomes; cytosolic fractions; and purified or heterologously expressed drug-metabolizing enzymes. It highlights the general principles of in vitro enzyme kinetics and the factors that determine the choice of each in vitro technology for biotransformation studies.
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Biotransformação , Avaliação Pré-Clínica de Medicamentos/métodos , Fígado/metabolismo , Animais , Humanos , Preparações Farmacêuticas/metabolismoRESUMO
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.
Assuntos
Didanosina/metabolismo , Avaliação Pré-Clínica de Medicamentos/métodos , Enalapril/metabolismo , Absorção Intestinal , Mucosa Intestinal/metabolismo , Jejuno/metabolismo , Propranolol/metabolismo , Zidovudina/metabolismo , Administração Oral , Adulto , Didanosina/administração & dosagem , Difusão , Enalapril/administração & dosagem , Feminino , Humanos , Técnicas In Vitro , Cinética , Masculino , Pessoa de Meia-Idade , Permeabilidade , Propranolol/administração & dosagem , Reprodutibilidade dos Testes , Solubilidade , Zidovudina/administração & dosagemRESUMO
The purpose of this study was to determine the effect of Bach's Magnificat on emotions, immune, and endocrine parameters in patients of specific infectious lung conditions. Participants (N = 40; 9 men & 31 women) ranging in age from 40 to 75 participated in the study. Patients were randomly allocated to an experimental and control group. During a 3-day period the experimental group received physiotherapy with the selected music, while the control group only received physiotherapy. ANOVA statistics indicate significant changes in the following parameters: POMS-scale, CD4+:CD8+ ratio, cortisol, and cortisol:DHEA ratio. The intervention of music demonstrates communication between the mind and body.
Assuntos
Afeto , Bronquite/metabolismo , Bronquite/terapia , Musicoterapia/métodos , Pneumonia Bacteriana/metabolismo , Pneumonia Bacteriana/terapia , Adulto , Idoso , Exercícios Respiratórios , Bronquite/imunologia , Linfócitos T CD4-Positivos/metabolismo , Linfócitos T CD8-Positivos/metabolismo , Terapia Combinada , Desidroepiandrosterona/sangue , Feminino , Humanos , Hidrocortisona/sangue , Masculino , Pessoa de Meia-Idade , Nebulizadores e Vaporizadores , Pneumonia Bacteriana/imunologia , Inquéritos e Questionários , Resultado do TratamentoRESUMO
The influence of an antioxidant vitamin supplement on immune cell response to prolonged exercise was determined using a randomized, double-blind, placebo-controlled, cross-over study. Twelve healthy endurance subjects (n = 6 male, n = 6 female; mean +/- SD for age, 30.1 +/- 6.2 yr; height, 1.76 +/- 7 m; body mass, 72.2 +/- 10.2 kg; VO2max, 63.7 +/- 12 ml x kg(-1) x min(-1)) participated in the study. Following a 3-week period during which subjects ingested a multivitamin and -mineral complex sufficient to meet the recommended daily allowance, they took either a placebo or an antioxidant vitamin supplement (containing 18 mg beta-carotene, 900 mg vitamin C, and 90 mg vitamin E) for 7 days prior to a 2-h treadmill run at 65% VO2max. Blood samples were drawn prior to and immediately following exercise. These were analyzed for neutrophil oxidative burst activity, cortisol and glucose concentrations, and white blood cell counts, as well as serum anti-oxidant vitamin concentrations. Plasma vitamin C, vitamin E, and beta-carotene concentrations significantly increased following 7-day supplementation (p < .05). In comparison to the placebo group, neutrophil oxidative burst was significantly higher following exercise (p < .05), but no differences were found in any other parameter following the 7-day supplementation period. Although the impact of exercise on neutrophil function is multifactorial, our data suggest that antioxidant supplementation may be of benefit to endurance athletes for the maintenance of this particular function of the innate immune system following the 7-day supplementation period.
Assuntos
Antioxidantes/farmacologia , Exercício Físico/fisiologia , Neutrófilos/efeitos dos fármacos , Explosão Respiratória/efeitos dos fármacos , Corrida/fisiologia , Adulto , Análise de Variância , Antioxidantes/administração & dosagem , Estudos Cross-Over , Suplementos Nutricionais , Método Duplo-Cego , Feminino , Humanos , Leucócitos/metabolismo , Masculino , Neutrófilos/metabolismo , Valores de Referência , Explosão Respiratória/fisiologia , Fatores de Tempo , Vitaminas/sangueRESUMO
Since the discovery of glucocorticoids, we have had a single strategy for manipulating the immune system in cases of destructive diseases mediated by uncontrolled immune responses. However, long-term use of immunosuppressive drugs can lead to the threat of opportunistic infections and malignancies. As we learn more about regulatory subsets of T lymphocytes and their cytokine profiles, the thrust has been on developing new ligands that ultimately give us more site-specific control. Our group has developed a patented mixture of plant sterols and sterolins that has anti-inflammatory properties and profound immune modulating effects on subsets of CD4+ T cells. We have tested this mixture in several clinical entities and we believe that it has wide applications in reverting immune abnormalities.