In vitro antioxidant properties of different parts of pomegranate flowers

The present study was designed to compare the antioxidant capacity of 70% ethanol extracts of petal, stamen and receptacle of pomegranate flowers (PF) by DPPH center dot, reducing power, hydroxyl radicals ((OH)-O-center dot), DNA degradation and DNA breaking assays, as well as the peroxide value (POV). The different parts of PF showed significant activities in all the free radical scavenging tests. Among the parts, receptacle exhibited the highest inhibition of 44.86%, 61.21% and 44.47% in DPPH center dot, (OH)-O-center dot and DNA degradation assays, respectively, and 63.96% reduction of ferricyanide to give Prussian blue colored complex in reducing power assay at maximum concentration tested, and showed the lowest POV of 68.51 meq/kg in experimental model of soybean oil after 12 days. Protection against oxidative damage to DNA molecules of various parts of flower was confirmed visually by DNA breaking assay. Total phenolic contents of the parts of flower and peel and leaves were estimated by Folin-Ciocalteu method and receptacle was found to contain the highest amount (148.41 +/- 6.25 mg/g) of phenolics among the parts of flower, but the phenolic content of flower (petal, stamen and receptacle) was lower than peel, higher than leaves. Linear correlation (R-2 = 0.7139-0.9987) between antioxidant potential of various parts in different assays and phenolic contents was observed. This preliminary study indicates the antioxidant activity of PF, and moreover the results showed correlation with the amount of phenolic content present in different parts. Therefore, all parts of PF could be considered as a significant natural antioxidant source. Crown Copyright (C) 2010 Published by Elsevier B.V. on behalf of The Institution of Chemical Engineers. All rights reserved.