Antioxidant properties of pomegranate juice and its scavenging effect on free radicals

Epidemiological findings have shown that consuming foods and beverages having high levels of phenolic compounds decreases the risk of many diseases such as cardiovascular ones. During recent years, there has been considerable interest in identifying natural sources with antioxidant activities to prevent oxidative stress- induced damages. The aim of this study was to measure phenolic compounds and antioxidant properties of pomegranate juice, its antioxidant capacity and scavenging effect on free radicals in comparison with other juices. In this experimental and laboratory study, antioxidant properties of pomegranate concentrate and also nine brand juices were evaluated. Phenolic compounds of pomegranate juice and the other samples were evaluated by means of Folin-Ciocalteu method, their antioxidant properties by FRAP method (Ferric Reducing/Antioxidant power Assay), and their power in scavenging the radical DPPH (1, 1-Diphenyl-2-Picrylhydrazyl) was measured. Besides, the capacity of pomegranate juice inhibitory effect on peroxidation of plasma lipids by copper ions and its inhibitory effect on controlling the hemolysis of erythrocytes induced by H2O2 were studied. The obtained data was analyzed by means of SPSS software. The most amount of phenolic compounds was found in pomegranate juice (205.05.0 mg Gallic acid equivalent to 100 ml of diluted pomegranate juice). Pomegranate also showed the highest total antioxidant capacity (11.170.3 mmol/l). In DPPH method whose radical scavenging activity was evaluated by the specific sample, pomegranate also showed its most capacity (96%).Correlative studies have shown that there is a positive and significant correlation between phenolic compounds content of the studied samples and their total antioxidant capacity in inhibiting or scavenging of DPPH radical. Studying the effect of different dilutions of pomegranate juice on inhibiting the formation of conjugated diene in plasma lipids and hemolysis of erythrocytes showed that in a dose-bound process the more the concentration of pomegranate juice, the more its inhibitory effect on hemolysis. On the basis of the results of this study, compared with other fruit juices studied pomegranate juice has more phenolic compounds and its total oxidant capacity is high besides, it has great strength in inhibiting different radicals and can have beneficial effects on improving antioxidant defence of the body and decreasing oxidative stress of it.