Fig. 2. Serum levels of dihydrotestosterone. Dihydrotestosterone levels were measured using a commercial ELISA kit. Values are expressed as mean±standard error of the mean (n=6). ^ap<0.001 compared to the control group. Statistical analyses were performed using ANOVA and Dunnett's multiple comparison test. BPH: benign prostate hyperplasia, CO: costunolide, DCL: dehydrocostus lactone.