Extraction of polyphenols from Trewia nudiflora L. and its antioxidant activity

Total phenoliccontent(TPC), specific polyphenols (Gallic, ellagic and protocatechuic acid),antioxidant activity (AOA), free radical scavenging activity (FRSA), lipid peroxidation (LPO), inhibition of nitroblue tetrazolium chloride (NBT) reduction caused by superoxide anions and reducing power (RP) through various extraction optimization parameters using solvents of different polarity, time, temperature and pH variation were evaluated in fruits, leaves, twigs and bark of Trewia nudiflora. The extraction parameters exhibited a broad range of TPC inplant parts varying from 7.9–668.6mg/g gallic acid equivalent(GAE), AOA 14.6–82.9% and RP 0.47–7.2ASE/ml. FRSA, measured as IC₅₀ invarious antioxidant assays ranged from 0.014–4.1mg/ml. The extracts of all plant parts showed significant protective effect against Fenton's reaction on supercoiled plasmid DNA pUC 18 assayed by agarose gel electrophoresis. Fruits were found to possess the highest TPC, AOA and FRSA in all the tested models, with reduction in the activity, in order of fruits > leaves > twigs > bark.