Determination of α-Amylase Inhibitory potential of leaf extracts of Rhododendron arboreum Sm. and Rhododendron campanulatum D. Don

The biological activity of plant-derived substances/metabolites may be considered as a source of new anti-enzyme drugs. Therefore, traditional Indian plants i.e. Rhododendron arboreum and R. campanulatum which are commonly used as remedies to control different diseases were screened to discover possible plant-derived α-amylase inhibitors. In the present investigation, inhibitory effects of leaf extracts of Rhododendron arboreum and R. campanulatum were determined against porcine α-amylase at a concentration range of 0.2-1.0 mg/mL. R. arboreum displayed 51.10, 44.00 and 35.40% inhibition at a concentration of 1 mg/mL for methanol, acetone and aqueous leaf extracts respectively. On the other hand, R. campanulatum showed 21.15, 18.25 and 15.85% α-amylase inhibition for methanol, acetone and aqueous extracts respectively at 1 mg/mL. The inhibitory activity increased altogether with increasing concentration of each plant extract. The results further indicated that methanol extracts of medicinal plants exhibited maximum inhibitory effects than other solvent (acetone, methanol) extracts. Keywords: Rhododendron arboreum, Rhododendron campanulatum, porcine α-Amylase, Leaf extracts, Inhibition