RESUMO
RATIONALE: Food Allergy Herbal Formula-2 (FAHF-2) provided protection against peanut anaphylaxis in a murine model and induced beneficial immune-modulation in humans. Butanol-refined FAHF-2, B-FAHF-2, retained safety and efficacy in the peanut allergic murine model at only 1/5 of FAHF-2 dosage. One compound, berberine, was isolated and identified in vitro as a bioactive component present in FAHF-2 and B-FAHF-2. The aim of this study was to investigate berberine as a chemical and pharmacokinetic marker of B-FAHF-2. METHODS: The consistency of constituents between B-FAHF-2 and FAHF-2 was tested. Peanut allergic C3H/HeJ mice were orally administered with 1mg of berberine or B-FAHF-2 containing an equivalent amount of berberine, and the ability to protect against peanut anaphylaxis and pharmacokinetic parameters were determined. Human intestinal epithelial cells (Caco-2) were cultured with berberine with or without the nine individual herbal constituents in B-FAHF-2, and the absorbed berberine levels were determined. RESULTS: Berberine is one of the major components in B-FAHF-2 and FAHF-2 formula. In a peanut allergic mouse model, B-FAHF-2, but not berberine, protected mice from anaphylaxis reactions. Pharmacokinetic profiles showed that the Cmax of B-FAHF-2 fed mice was 289.30±185.40ng/mL; whereas berberine alone showed very low bioavailability with Cmax value of 35.13±47.90ng/mL. Caco-2 cells influx assay showed that 7 of 9 herbal constituents in B-FAHF-2 increased berberine absorption at rates ranging from 18 to 205%. CONCLUSIONS: B-FAHF-2 remarkably increased the bioavailability of berberine. Berberine can be used as chemical and pharmacokinetic marker of B-FAHF-2. Other herbal components in B-FAHF-2 may facilitate the absorption of berberine.
Assuntos
Alérgenos/imunologia , Anafilaxia/prevenção & controle , Berberina/imunologia , Hipersensibilidade a Amendoim/tratamento farmacológico , Extratos Vegetais/imunologia , Alérgenos/química , Anafilaxia/etiologia , Animais , Berberina/química , Butanóis/química , Células CACO-2 , Feminino , Humanos , Imunoglobulina E/sangue , Interferon gama/metabolismo , Interleucina-5/metabolismo , Camundongos , Camundongos Endogâmicos C3H , Hipersensibilidade a Amendoim/complicações , Extratos Vegetais/químicaRESUMO
Antagonizing the action of the human nuclear xenobiotic receptor pregnane X receptor (PXR) may have important clinical implications in preventing drug-drug interactions and improving therapeutic efficacy. We provide evidence that a naturally occurring phytoestrogen, coumestrol, is an antagonist of the nuclear receptor PXR (NR1I2). In transient transfection assays, coumestrol was able to suppress the agonist effects of SR12813 on human PXR activity. PXR activity was assessed and correlated with effects on the metabolism of the anesthetic tribromoethanol and on gene expression in primary human hepatocytes. We found that coumestrol was able to suppress the effects of PXR agonists on the expression of the known PXR target genes, CYP3A4 and CYP2B6, in primary human hepatocytes as well as inhibit metabolism of tribromoethanol in humanized PXR mice. Coumestrol at concentrations above 1.0 microm competed in scintillation proximity assays with a labeled PXR agonist for binding to the ligand-binding cavity. However, mammalian two-hybrid assays and transient transcription data using ligand-binding-cavity mutant forms of PXR show that coumestrol also antagonizes coregulator recruitment. This effect is likely by binding to a surface outside the ligand-binding pocket. Taken together, these data imply that there are antagonist binding site(s) for coumestrol on the surface of PXR. These studies provide the basis for development of novel small molecule inhibitors of PXR with the ultimate goal of clinical applications toward preventing drug-drug interactions.
Assuntos
Cumestrol/farmacologia , Fitoestrógenos/farmacologia , Receptores de Esteroides/antagonistas & inibidores , Animais , Hidrocarboneto de Aril Hidroxilases/genética , Hidrocarboneto de Aril Hidroxilases/metabolismo , Linhagem Celular , Células Cultivadas , Receptor Constitutivo de Androstano , Cumestrol/química , Cumestrol/metabolismo , Citocromo P-450 CYP2B6 , Citocromo P-450 CYP3A/genética , Citocromo P-450 CYP3A/metabolismo , Etanol/análogos & derivados , Etanol/metabolismo , Feminino , Expressão Gênica/efeitos dos fármacos , Histona Acetiltransferases/genética , Histona Acetiltransferases/metabolismo , Humanos , Imuno-Histoquímica , Espectrometria de Massas , Camundongos , Camundongos Knockout , Camundongos Transgênicos , Microscopia Confocal , Coativador 1 de Receptor Nuclear , Oxirredutases N-Desmetilantes/genética , Oxirredutases N-Desmetilantes/metabolismo , Fitoestrógenos/química , Fitoestrógenos/metabolismo , Receptor de Pregnano X , Ligação Proteica , Receptores Citoplasmáticos e Nucleares/genética , Receptores Citoplasmáticos e Nucleares/metabolismo , Receptores de Esteroides/genética , Receptores de Esteroides/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Técnicas do Sistema de Duplo-HíbridoRESUMO
Steaming ginseng at high temperature increased its cytotoxicity to SK-Hep-1 hepatoma cancer cells. HPLC separation and fractionation followed by MTT assay revealed that ginsenosides Rg3, Rg5, Rk1, Rs5, and Rs4 are the active principles. Their 50% growth inhibition concentration (GI50) values were 41, 11, 13, 37, and 13 microM, respectively. Cisplatin had a GI50 of 84 microM in the same assay conditions.