In-vitro Antioxidant Potential from the Leaves of Punica granatum Linn. Grown in Bangladesh

The crude ethanolic extract of the leaves of Punica granatum Linn. (Family: Punicaceae) was evaluated for its possible antioxidant activities growing in northeast part of Bangladesh. Five complementary test systems, namely DPPH free radical scavenging, nitric oxide scavenging, reducing power, Fe++ ion chelating ability and total phenolic content were used for determining antioxidant activities of the leaf extract. In DPPH free radical scavenging test, IC50 value for ethanolic crude extract was found fairly significant 23.45 +/- 0.062 mu g/ml while compared to the IC50 value of the reference standards ascorbic acid and Butylated Hydroxy Anisole (BHA) (5.23 +/- 0.034 and 6.15 +/- 0.027 mu g/ml) respectively. The ethanol extract showed maximum nitric oxide (NO) scavenging activity of 76.55 +/- 0.89% at 100 mu g/ml, where as ascorbic acid exhibited 88.43 +/- 0.81% inhibition at the same concentration. The IC50 value for nitric oxide scavenging test was also found significant (55.65 +/- 0.072 mu g/ml) while compared to the IC50 value of the reference standard ascorbic acid (31.38 +/- 0.047 mu g/ml). The maximum absorbance for reducing power assay was found to 2.015 at 100 mu g/ml while compared to 2.817 and 2.031 for standard ascorbic acid and BHA respectively. The IC50 value of the extract as percentage of Fe++ ion chelating ability was determined as 65.109 mu g/ml where that of EDTA showed 8.75 mu g/ml. The total phenolic amount was also calculated as quite high in ethanolic crude extract 378.37 mg/g of gallic acid equivalent. Therefore, the obtained results tend to suggest the antioxidant activities of the crude ethanolic extract of the leaves of P. granatum and justify its use in folkloric remedies.