Activation of Rho-kinase 2 (ROCK-II) results in contraction of corpus cavernosum smooth muscle and ROCK-II inhibitors relax corpus cavernosum in vitro and in vivo hence, plant extracts capable of inhibiting ROCK-II enzyme may be useful in management of erectile dysfunction (ED). The aim of the study was to screen selected Indian medicinal plants, having similar ethnopharmacological use for ROCK-II inhibition.
Materials and methods
Some Indian medicinal plants reported as aphrodisiacs in Ayurveda and modern scientific literature were collected, authenticated and extracted. Direct methanol and successive aqueous extracts of these plants were screened for ROCK-II inhibitory activity using HTRF® KinEASE™ STK S2 Kit (Cisbio Bioassays). Relaxant effect of potent extract was recorded on isolated rat corpus cavernosum.
Results
Methanolic and successive aqueous extracts of 30 plants were screened for ROCK-II inhibition and 15 herbal extracts showed inhibition ranging between 50 and 88% at 50 μg/mL. While IC50 of Y-27632, a standard ROCK-II inhibitor, was found to be 163.8±1.2 nM. The Methanolic extract of Terminalia chebula (METC) with IC50 value of 6.09±0.17 μg/mL was found to be most potent and relaxed isolated rat corpus cavernosum significantly (p