Exploring the Volatile Organic Compounds, Pigments, Phenolics and In vitro Bioactivities of Betel Leaves from Vietnam

Abstract

Betel (Piper betle L.), a vine growing primarily in Southeast Asian countries, are widely used in folk medicine to prevent and treat indigestion, cough, bronchitis and asthma. The aims of the study were to determine volatile constituents and pigments as well as to compare phenolic composition, antioxidant activity and enzyme inhibitory effects of betel leaf extracts obtained with different organic solvents. The results showed that the sample was composed of various major volatile organic compounds, of which eugenol, g-muurolene and d-cadinene accounted for more than 64%. It was also a rich source of pigments, including lutein (400.68 mg/g) and zeaxanthin (101.68 mg/g). The ethyl acetate extract had the highest total phenolic content (71.72 ± 0.54 mg GAE/g) despite containing low levels of the phenolic compounds examined in the study. The acetonic extract generally showed higher antioxidant activity compared to the others. The methanolic extract exhibited the strongest inhibitory effects on a-amylase (597.23 ± 59.06 mg/mL) and xanthine oxidase (43.07 ± 1.69 mg/mL). The findings of the study could be useful for designing therapeutic agents derived from betel leaves.