Antioxidant properties and free radicals scavenging activities of pomegranate (Punica granatum L.) peels: An in-vitro study

Fruit peels often contain more bioactive substances than the edible component of the fruit. As a result, the current study was designed to use a variety of in-vitro assays to investigate the antioxidant capacity of phenolic compounds found in pomegranate ( Punica granatum L.) peel. The IC 50 values for DPPH free radical scavenging activity, ABTS assay, and lipid peroxidation inhibition activity were as low as 0.1, whereas the same for hydroxyl radical scavenging activity was 0.6 μg/ml. The nitric oxide scavenging activity had the lowest IC 50 value (0.02 μg/ml). At a concentration of 0.21 μg/ml, phenolics scavenged ∼60% of DPPH radicals, while at a phenolic content of 98.9 μg/ml, the extract chelated 60% of the iron metal. The RP 0.5AU value of total reducing power was 0.37 μg/ml. Total antioxidant activity (AO 0.5AU value of 4.24 μg/ml) was significantly lower than the standard (8.42 g/ml). At a dose of 0.09 μg/ml, phenolics reduced lipid peroxidation by 53% in an egg homogenate model. Gel electrophoresis indicated that the extracts with phenolic content of 20 and 40 μg virtually protected the BSA against AAPH-induced oxidation . Overall, various experiments showed that pomegranate peel extract has significant antioxidant activity and supports its use as a source of natural antioxidants to combat autoxidation-induced pathologies or diseases and use in the health food/nutraceutical/pharmaceutical industry for a variety of applications. • The IC 50 values of pomegranate peel extract for DPPH free radical scavenging activity, ABTS assay, and lipid peroxidation inhibition activity were all less than 0.1, while the IC 50 value for hydroxyl radical scavenging activity was 0.6 µg/ml. • The nitric oxide scavenging action had the lowest IC 50 value (0.02 µg/ml). • Total antioxidant activity (AO 0.5AU = 4.24 µg/ml) was significantly lower than the standard (8.42 µg/ml). • The extract can almost entirely suppress AAPH-induced protein breakdown.