[Effects of byakushi and ogon on the hepatic drug metabolizing enzymes in rats].

The effect of single or daily oral administration of hot water extracts (HWE) from Byakushi or Ogon on rat hepatic drug-metabolizing enzymes were investigated in vivo. Enzymes were measured for 3 to 72 hr after single oral administration of HWE at the dose of 1.0 g/kg or 5.0 g/kg. Administration of 1.0 g/kg of Byakushi and 5.0 g/kg of Ogon inhibited aniline hydroxylase activity, while 5.0 g/kg of Byakushi inhibited it in the early phase, but increased it in the late phase. Byakushi inhibited aminopyrine N-demethylase activity, while 5.0 g/kg of Ogon increased it. Byakushi and Ogon decreased the amount of cytochrome P-450. Byakushi and Ogon increased the amount of cytochrome b5. Byakushi increased cytochrome c reductase activity 3 hr after administration and decreased it 6 and 12 hr after administration. In contrast, 1.0 g/kg of Ogon decreased cytochrome c reductase activity, and 5.0 g/kg increased it 6 hr after administration and decreased it 12 hr after administration. At 24 hr after the last administration to animals treated with a regimen of once a day administration of the HWE (0.1 or 1.0 g/kg) of Byakushi or Ogon for 14 days, the enzymes were measured. Byakushi decreased aminopyrine N-demethylase activity, the amount of cytochrome P-450, and cytochrome c reductase activity. Ogon decreased cytochrome c reductase activity. Byakushi altered the composition of cytochrome P-450 isozyme after daily administration.