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1.
Am J Ther ; 19(5): 351-6, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22964559

RESUMO

Science, including rigorous basic scientific research and rigorous clinical research, must underlie both the development and the clinical use of herbal medicines. Yet almost none of the hundreds or thousands of articles that are published each year on some aspect of herbal medicines, adheres to 3 simple but profound scientific principles must underlie all of herbal drug development or clinical use. Three fundamental principles that should underlie everyone's thinking about the development and/or clinical use of any herbal medicine. (1) There must be standardization and regulation (rigorously enforced) of the product being studied or being used clinically. (2) There must be scientific proof of a beneficial clinical effect for something of value to the patient and established by rigorous clinical research. (3) There must be scientific proof of safety (acceptable toxicity) for the patient and established by rigorous clinical research. These fundamental principles of science have ramifications for both the scientist and the clinician. It is critically important that both the investigator and the prescriber know exactly what is in the studied or recommended product and how effective and toxic it is. We will find new and useful drugs from natural sources. However, we will have to learn how to study herbal medicines rigorously, and we will have to try to convince the believers in herbal medicines of the wisdom and even the necessity of a rigorous scientific approach to herbal medicine development. Both biomedical science and practicing physicians must enthusiastically accept the responsibility for searching for truth in the discovery and development of new herbal medicines, in the truthful teaching about herbal medicines from a scientific perspective, and in the scientifically proven clinical use of herbal medicines.


Assuntos
Descoberta de Drogas/métodos , Medicina Herbária , Fitoterapia , Animais , Pesquisa Biomédica/métodos , Desenho de Fármacos , Humanos , Fitoterapia/efeitos adversos , Preparações de Plantas/efeitos adversos , Preparações de Plantas/química , Preparações de Plantas/farmacologia , Plantas Medicinais/química
2.
Planta Med ; 75(10): 1129-33, 2009 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-19326326

RESUMO

Phase 2 detoxification enzymes protect against carcinogenesis and oxidative stress. Ginseng ( PANAX spp.) extracts and components were assayed for inducer activity of NQO1 (quinone reductase), a phase 2 enzyme, in Hepa1c1c7 cells. Ginseng extracts were analyzed for ginsenosides and panaxytriol. Korean red PANAX GINSENG extracts demonstrated the most potent phase 2 enzyme induction activity (76,900 U/g dried rhizome powder and 27,800 U/g for two similar preparations). The ginsenoside-enriched HT-1001 American ginseng ( PANAX QUINQUEFOLIUS) extract was the next most potent inducer, with activity of 15,900 U/g, followed by raw American ginseng root with activity of 8700 U/g. Neither a polysaccharide-enriched extract of American ginseng nor a commercial white PANAX GINSENG preparation showed any inducer activity. Pure ginsenosides showed no inducer activity. Protopanaxadiol and protopanaxatriol, deglycosylated ginsenoside metabolic derivatives, showed potent induction activity (approximately 500,000 U/g each). Synthetic panaxytriol was over 10-fold more potent (induction potency 5,760,000 U/g). There was no correlation between ginsenoside content and phase 2 enzyme induction. The most potent inducing red ginseng extract also had the highest panaxytriol content, 120.8 microg/g. We found that ginseng induced NQO1 and that polyacetylenes are the most active components.


Assuntos
NAD(P)H Desidrogenase (Quinona)/biossíntese , Panax , Extratos Vegetais/farmacologia , Linhagem Celular , Cromatografia Líquida de Alta Pressão , Indução Enzimática , Humanos , Panax/química
3.
J Clin Pharmacol ; 48(5): 599-609, 2008 May.
Artigo em Inglês | MEDLINE | ID: mdl-18319359

RESUMO

Human immunodeficiency virus (HIV)-infected patients often take herbal medicines, which may interact with antiretrovirals. American ginseng induces phase 2 and antioxidant enzymes in vitro and might increase the clearance of zidovudine and/or enhance antioxidant activity. Ten healthy volunteers received 300 mg of zidovudine orally before and after 2 weeks of treatment with a ginsenoside-enriched American ginseng extract 200 mg twice daily. This ginseng extract induced the phase 2 enzyme quinone reductase with an average concentration of doubling of enzyme activity of 190 microg/mL. Total ginsenoside content was 8.5 +/- 0.5%. Pharmacokinetic profiles of zidovudine and oxidative stress marker concentrations were measured post-zidovudine dose. American ginseng does not significantly affect the formation clearance of zidovudine to its glucuronide (ratio post- to pre-American ginseng = 1.17; 90% confidence interval: 0.95-1.45; P = .21), total clearance (ratio = 0.97; 0.82-1.14; P = .70), or plasma zidovudine AUC0-8 (ratio = 1.03; 0.87-1.21; P = .77). Oxidative stress biomarkers are reduced post-American ginseng (F2-isoprostane ratio = 0.79; 0.72-0.86; P < .001; 8-hydroxy-deoxyguanosine ratio = 0.74; 0.59-0.92; P = .02). Two weeks of American ginseng does not alter zidovudine pharmacokinetics but reduces oxidative stress markers.


Assuntos
Ginsenosídeos/farmacologia , Infecções por HIV/tratamento farmacológico , NAD(P)H Desidrogenase (Quinona)/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Panax/química , Zidovudina/farmacocinética , 8-Hidroxi-2'-Desoxiguanosina , Fármacos Anti-HIV/farmacocinética , Antioxidantes/metabolismo , Área Sob a Curva , Biomarcadores Farmacológicos/análise , Biomarcadores Farmacológicos/metabolismo , Células Cultivadas , Cromatografia Líquida de Alta Pressão , Desoxiguanosina/análogos & derivados , Desoxiguanosina/urina , Relação Dose-Resposta a Droga , Interações Medicamentosas , F2-Isoprostanos/sangue , Feminino , Ginsenosídeos/administração & dosagem , Ginsenosídeos/metabolismo , Infecções por HIV/metabolismo , Inibidores da Protease de HIV/farmacocinética , Humanos , Masculino , Taxa de Depuração Metabólica , NAD(P)H Desidrogenase (Quinona)/sangue , Fitoterapia , Extratos Vegetais/administração & dosagem , Extratos Vegetais/metabolismo , Extratos Vegetais/farmacologia , Zidovudina/análogos & derivados , Zidovudina/sangue , Zidovudina/urina
4.
J Allergy Clin Immunol ; 110(5): 713-20, 2002 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-12417879

RESUMO

BACKGROUND: With the expiration of the patent on albuterol metered-dose inhalers (MDIs) in 1989, methods to assess in vivo bioequivalence of generic formulations required investigation. OBJECTIVE: In an effort to develop a sensitive method to document bioequivalence, bronchoprovocation with methacholine chloride was used to assess the dose-response relationship of albuterol as delivered by MDI. Sensitivity was assessed in terms of magnitudes of ED(50), the estimated albuterol dose required to achieve 50 % of the fitted maximal value of the pharmacodynamic effect above baseline, and change in response as a function of dose, with emphasis on 1 and 2 actuations. METHODS: On separate study days, 15 nonsmokers with mild asthma received randomized nominal albuterol doses of 0 to 576 microg by using specially manufactured MDI canisters. FEV(1) was measured 15 minutes after MDI dosing. Serially increasing doses of methacholine were administered, and FEV(1) was measured after each methacholine dose until a 20 % decrease in FEV(1) (PD(20)) was achieved. RESULTS: Mean PD(20) values after use of each of the albuterol-containing MDIs were significantly greater than either mean screening or mean placebo PD(20) values (P <.05). Mean responses and most individual subject responses to 1 and 2 actuations (90 and 180 microg) of albuterol MDI were within the sensitive region of the dose- response curve. The mean estimated ED(50) value on the basis of nonlinear mixed effect modeling was 119.2 microg (range, 33.3-337.1 microg), with an intersubject percentage coefficient of variation of 69.0 %. CONCLUSIONS: The methacholine bronchoprovocation model is safe and useful in the study of albuterol MDI dose-response in asthmatic subjects. Bronchoprovocation studies may be used for determination of bioequivalence of multisource albuterol MDI products.


Assuntos
Agonistas Adrenérgicos beta/farmacologia , Albuterol/farmacologia , Testes de Provocação Brônquica/métodos , Broncoconstritores/farmacologia , Broncodilatadores/farmacologia , Inaladores Dosimetrados , Cloreto de Metacolina/farmacologia , Administração por Inalação , Adolescente , Agonistas Adrenérgicos beta/administração & dosagem , Adulto , Albuterol/administração & dosagem , Asma/diagnóstico , Asma/tratamento farmacológico , Teorema de Bayes , Broncodilatadores/administração & dosagem , Estudos Cross-Over , Relação Dose-Resposta a Droga , Feminino , Volume Expiratório Forçado , Humanos , Masculino , Sensibilidade e Especificidade
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