Phytochemical composition, β-glucuronidase inhibition, and antioxidant properties of two fractions of Piper betle leaf aqueous extract.

Abstract

Piper betle leaf, used as masticatory in South Asia, is also medicinally important. This work was done to analyze phytochemical composition of two solvent fractions (chloroform and ethyl acetate) of the aqueous extracts obtained from eight varieties of P. betle leaves and to identify the active components against β-glucuronidaseby chemometric analysis. Twenty-four phenolic compounds, in addition to different organic acids, fatty acids, amino acids, sugars, and polyols, were identified from the solvent fractions. The extracts inhibited the enzyme β-glucuronidase. Piceatannol was the most active constituent against the enzyme (activity 12 times higher than that of silymarin), Chlorogenic acid also inhibited β-glucuronidase (activity 4.4 times higher when compared to silymarin). 2,2'-Diphenyl-1-picrylhydrazyl and superoxide free radical scavenging activities of both the fractions of eight varieties of P. betle leaf extracts showed very strong antioxidant potentiality. The findings validated some medicinal properties of the said leaves. Edible leaves of Piper betle are medicinally and economically important. Leaves of different local varieties are reported to be used for the treatment of different diseases. The leaves have many biological properties, hepatoprotection being one of them. A large number of rural population is economically dependent on the cultivation of betel vine. But with a rapid change in lifestyle, the chewing habit of P. betle is decreasing ultimately affecting the livelihood of farmers dependent on betel cultivation. Knowledge on β-glucuronidase inhibitory activity and the mechanism for hepatoprotection of different P. betle varieties may validate the medicinal properties of betel, which would increase consumption of these leaves.