Evaluation of 5α-reductase inhibitory activity of certain herbs useful as antiandrogens

This study demonstrates 5 alpha-reductase inhibitory activity of certain herbs useful in the management of androgenic disorders. Ganoderma lucidum (Curtis) P. Karst (GL), Urtica dioica Linn. (UD), Caesalpinia bonducella Fleming. (CB), Tribulus terrestris Linn. (TT), Pedalium murex Linn. (PM), Sphaeranthus indicus Linn. (SI), Cuscuta reflexa Roxb. (CR), Citrullus colocynthis Schrad. (CC), Benincasa hispida Cogn. (BH), Phyllanthus niruri Linn. (PN) and Echinops echinatus Linn. (EE) were included in the study. Petroleum ether, ethanol and aqueous extracts of these herbs were tested for their 5 alpha-reductase inhibitory activity against the standard 5 alpha-reductase inhibitor, finasteride. A biochemical method to determine the activity of 5 alpha-reductase was used to evaluate the inhibition of different extracts to the enzyme. The optical density (OD) value of each sample was measured continuously with ultraviolet spectrophotometer for the reason that the substrate NADPH has a specific absorbance at 340 nm. As the enzyme 5 alpha-reductase uses NADPH as a substrate, so in the presence of 5 alpha-reductase inhibitor, the NADPH concentration will increase with the function of time. This method thus implicates the activity of 5 alpha-reductase. The method proved to be extremely useful to screen the herbs for their 5 alpha-reductase inhibitory potential. GL, UD, BH, SI and CR came out to be promising candidates for further exploring their antiandrogenic properties.