Antioxidant activity of Piper betle L. leaf extract in vitro

Piper betle leaves are used as masticatory in Asian countries. In the present study, antioxidant activities of aqueous extracts of three local varieties of P. betle leaves were evaluated by several in vitro systems, e.g. DPPH radical scavenging activity, superoxide radical scavenging activity in a riboflavin/light/NBT system, hydroxyl radical scavenging activity and inhibition of lipid peroxidation induced by FeSO4 in egg yolk. Total antioxidant activity was measured by the reduction of Mo(VI) to Mo(V), by the extract, and subsequent formation of a green phosphate/Mo(V) complex at acid pH. The extracts were found to have different levels of antioxidant activity in the systems tested. The data indicate that the antioxidant activities differed in varieties. The antioxidant activities of the three varieties are in the order Kauri > Ghanagete > Bagerhati. All three varieties of P. betle have more potential to prevent lipid peroxidation than does tea. Total antioxidant capacity (equivalent to gallic acid) of Kauri is also higher than tea. Total phenolic concentration, expressed as gallic acid equivalents showed correlation with the antioxidant activity, being highest in Kauri and lowest in Bagerhati.