RESUMEN
<p><b>OBJECTIVE</b>To investigate the effects of the ethyl acetate extract of Semen Hoveniae (ESH) on liver microsomal cytochrome P450 isoenzyme in rats.</p><p><b>METHOD</b>The rats were given orally the ESH in the doses of 0.14, 0.17, 0.2 g x kg (equivalent to the crude herb) for 10 days respectively. Rat liver microsomal cytochrome P450, NADPH-Cyt C reductase, erythromycin N-demethylase (ERD), Aniline hydroxylase (ANH), aminopyrine N-demethylase (ADM) activities were quantitated by UV chromatography. The levels of mRNA expression of CYP1A1, CYP2C11, CYP2E1 and CYP3A1 were detected by semi-quantitative reverse transcripatase-polymerase chain reaction (RT-PCR).</p><p><b>RESULT</b>The cytochrome P450 content, NADPH-Cyt C reductase activities and erythromycin N-demethylase (ERD) activities were not affected. Aniline hydroxylase (ANH) activities in liver were decreased by up to35.1%; aminopyrine N-demethylase (ADM) activitiesin liver were increased by up to 42.4%. The mRNA expression of CYP1A1, CYP2C11 and CYP3A1 were found to be increased markedly.</p><p><b>CONCLUSION</b>A specific effect of ESH on liver microsomal cytochrome P450 isoenzyme in rats was observed in this investigation. ESH had various effects on liver microsomal cytochrome P450 isoenzyme.</p>