Inhibitory Effects of Serenoa Repens on the Kinetics of Pig Prostatic Microsomal 5α-Reductase Activity

The study from 26 years ago explored the impact of Serenoa repens (Saw palmetto) extract on 5α-reductase activity in pig prostatic microsomes. It was found that the enzyme activity displayed two peaks at pH 5.5 and 8.0, indicating the presence of both type 1 and type 2 isozymes. The Serenoa repens extract was shown to inhibit 5α-reductase through various types of inhibition, suggesting that the extract's diverse fatty acids might induce conformational changes in the enzyme, hindering its interaction with testosterone and NADPH. The study also noted the antiandrogenic and antiestrogenic activities of different fractions of the extract. The research involved microsomes prepared from the prostatic tissue of three noncastrated male Duroc pigs and used radiolabeled testosterone to assess enzyme activity, with the inhibition assays conducted at pH 5.5 using S. repens extracts.