¹Institute of Pharmaceutical Sciences, National Institutes of Health, University of the Philippines Manila, Manila, Philippines
²Department of Pharmacy, College of Pharmacy, University of the Philippines Manila, Manila, Philippines DOI : 10.29228/jrp.478 Tamarindus indica seeds have important roles in the field of health sciences. The seeds are used in traditional medicine due to their beneficial effects on urologic disorders, including benign prostatic hyperplasia. The present study evaluates the inhibitory activity of T. indica seed extracts against 5α-reductase (5αR). This enzyme is responsible for the conversion of testosterone to dihydrotestosterone, which stimulates prostatic enlargement. Seeds were separately extracted with ethanol, ethyl acetate, and hexane. The inhibitory activity of the extracts was assessed in the presence of testosterone and 5αR from mouse liver. Unchanged testosterone was quantified by high-performance liquid chromatography with photodiode array detector. Inhibition was calculated based on the remaining testosterone and was expressed as dutasteride equivalent 5αR inhibitory activity (DE; μg dutasteride equivalent per mg extract). The most active extract underwent phytocompound profiling by ultra-performance liquid chromatography quadruple timeof- flight mass spectrometric analysis. The results showed that ethyl acetate extract was the most active 5αR inhibitor with a DE value of 153.31 ± 10.60. Fifteen phytocompounds from the classes of tocopherol, fatty acid, phytosterol, saponin, terpenoid, and phenolic compounds were identified, which may be partly responsible for the inhibitory activity of the extract. The findings indicate that T. indica seeds can be a source of 5αR inhibitors. Keywords : 5α-reductase; benign prostatic hyperplasia; dihydrotestosterone; Tamarindus indica; testosterone