Inhibition of 3-hydroxy-3-methylglutaryl coenzyme a (hmg-coa) reductase (ex vivo) by medicinal plants from Western Ghats

Medicinal plants are being explored as natural inhibitors of HMG-CoA reductase (vital enzyme in cholesterol biosynthesis) as the drugs (statins), used in the management of hypercholesterolemia, are associated with side effects. In this study, medicinal plants: Abrus precatorius Linn. (AP), Canthium parviflorum Lam. (CP) and Costus speciosus (Koenig)Sm. (CS) were studied for phytochemical composition and the ability of methanol extract (300 .g) to inhibit HMG-CoA reductase activity, using HMG-CoA as a substrate. The assay is based on the stoichiometric formation of Coenzyme A during the reduction of microsomal HMG-CoA to mevalonate. Phytochemicals glutathione, tannins, alkaloids and vitamin C were at higher amount in AP, CP and was rich in flavonoids and . tocopherol and polyphenols, .-carotene, saponins and steroidal saponins presence was indicated in CS. The plants showed varying degree of inhibition of HMG-CoA reductase. The CoA released at the end of assay in the control (119.70 nM) and statins (94.46 nM) was higher than that released in systems, containing CS (72.97 nM) > CP (55.41 nM) >AP (50.23 nM) extracts. From the results, it can be concluded that all the three plants studied possess HMG-CoA reductase inhibitory activity, indicating scope for their utilization as cholesterol lowering agents. However, further studies are needed, before recommending them as safe therapeutic agents