Kinetics of α -glucosidase inhibitory activity and phytochemical analysis of Piper crocatum Ruiz & Pav. leaves ethanol extract

α-Glucosidase is an enzymes group that playing essential roles in the digestion of polysaccharide. Inhibitor of a-glucosidase can decrease polysaccharide digestion rate and therefore plays a significant function in preventing the development of diabetes (type 2). Piper crocatum Ruiz & Pav. is an essential herb applied traditionally in Indonesia to treat diabetes mellitus. This work evaluated the a-glucosidase inhibitory activity of P. crocatum leaves ethanol extract. Phytochemical component of the extract was also analyzed. The α-glucosidase inhibitory activity of the P. crocatum leaves ethanol extract was examined by reacting its different concentrations with α-glucosidase and p-nitrophenyl glucopyranoside. Kinetics of the α-glucosidase inhibition was determined using a Lineweaver-Burke plot. Phytochemical in the extract was determined using GC-MS. Ethanol extract of P. crocatum leaves exhibited moderate α-glucosidase inhibitory activity compared with acarbose. Phytochemical analyses showed the presence of stilbene, linolenic acid, phenol, phytosteroid, and α-tocopherol. The competitive action of P. crocatum  leaves ethanol extract is due to its inhibitory effects on α-glucosidase. The stilbene and phenol compounds indicated responsible for anti-diabetic activity from P. crocatum leaves ethanol extract.