Comparison between chinese medical herb Pueraria lobata crude extract and its main isoflavone puerarin antioxidant properties and effects on rat liver CYP-catalysed drug metabolism.
Life Sci
; 67(24): 2997-3006, 2000 Nov 03.
Article
em En
| MEDLINE
| ID: mdl-11133012
ABSTRACT
Ge-gen (Radix Puerariae; RP) is used in traditional oriental medicine for various medicinal purposes. The drug is the root of a wild leguminous creeper, Pueraria lobata (Willd) Ohwi. It possesses a high content of flavonoid derivatives, the most abundant of which is puerarin (PU). Here, using the enhanced chemiluminescence technique based on horseradish peroxidase and a luminol-oxidant-enhancer reagent, we evaluated in vitro the antioxidant activity of PU and RP crude extract. Both biological samples inhibited the steady-state chemiluminescent reaction in a dose-dependent fashion. However, different inhibition mechanism were postulated, since only RP behaved like conventional antioxidants. This activity was supposed to be due the presence of compounds other than PU in the crude extract. Using each of the specific substrates to different cytochrome P450 (CYP) isoforms or the regio- and stereo-selective hydroxylation of testosterone as polyfunctional probe we found that when intragastrically administered in male Wistar rats, PU (100 or 200 mg/kg b.w.) and RP (700 or 1,400 mg/kg b.w.) significantly altered hepatic CYP-linked monooxygenases. While both CYP content and NADPH-(CYP)-c-reductase activity were significantly increased in all situations, a complex pattern of CYP modulation was observed, including both induction (PU CYP2A1, 1A1/2, 3A1, 2C11; RP CYP1A2, 3A1, 2B1) and inactivation (PU and RP CYP3A, 2E1, 2B1), the latter being due to either parental agents or metabolites, as demonstrated by in vitro studies. Overall, these findings indicate that RP contains compounds with potent antioxidant activity and that both PU and RP impairs CYP-catalysed drug metabolism.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Microssomos Hepáticos
/
Medicamentos de Ervas Chinesas
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Sistema Enzimático do Citocromo P-450
/
Isoflavonas
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Antioxidantes
Limite:
Animals
Idioma:
En
Revista:
Life Sci
Ano de publicação:
2000
Tipo de documento:
Article
País de afiliação:
Itália