Briefly, the reaction solution contained 0.2 ml of various plant extracts in 50% ethanol, 1.0 ml of 0.02 mM phosphate buffer (pH 6.5), 0.3 ml of 500 ppm testosterone in 50% ethanol, and 1.0 ml of rat microsomal suspension. Reactions were then initiated by the addition of 0.5 ml of 0.77 mg/ml NADPH in phosphate buffer,