Inhibition of Rat 5α-Reductase Activity and Testosterone-Induced Sebum Synthesis in Hamster Sebocytes by an Extract of Quercus acutissima Cortex

Figure 2

Quantification of inhibitory effect of BK on rat liver microsomal 5α-reductase activity. Testosterone was incubated at a final concentration of 3.5 μmol/L for 30 min in the presence or absence of rat liver microsomes (40 μg/mL) and the cofactors. Bokusoku (BK) was added to the reactions at 3, 10, 30, or 100 μg/mL before starting the reaction. Testosterone remaining was extracted with ethyl acetate after the incubation and quantified by HPLC technique. Data are shown as relative amounts of testosterone, which are a percentage of testosterone alone control reaction. .