Studies on in-vitro antioxidant activities of Carica papaya aqueous leaf extract.

The free radical scavenging activity of the aqueous leaf extraction of Carica papaya was studied by using different anti oxidant models of screening.e.g lipid peroxide(rat brain and liver),1,1-diphenyle hydrazyl (DPPH) ,2,2azinobis –(3-ethyle benzothiazoline -6-sulphonate) (ABTS) ,nitric oxide ,super oxide and hydroxyl radical model. The extract showed good dose dependent free radical scavenging activity in all the in vitro models. IC50 values were found to be 198,141,185,244, 323, 461 and 922 µg/ml respectively in DPPH, ABTS, nitric oxide, superoxide, hydroxyl ion, lipid peroxidation (liver and brain) inhibition assays. However the extract showed only moderate scavenging activity of hydroxyl radical and anti lipid peroxidation potential, which was performed using rat liver and brain homogenate. The results were observed in a concentration dependent manner. All the above in vitro studies clearly indicate that aqueous extract of Carica papaya has a significant antioxidant activity.