Estimation of total phenols with special emphasis to antioxidant potentials of few hypericum species

Summary In present investigation, the phenolic content and antioxidant activity of leaf extracts (methanolic) of Hypericum mysorense, H. perforatum, H. japonicum and H. patulum were studied. Various in vitro antioxidant models (ABTS, DPPH, H2O2, Nitric oxide, LPO, Alkaline DMSO, pNDA) were carried out for all methanolic extracts of hypericum species. The total phenolic and flavanol content were performed in order to correlate whether the antioxidant activity of extracts is influenced by the concentration of flavonols and/or phenols present. The higher percentage of total phenolic and flavonol content was found to be 24.72 and 101.7 mg/g in H. mysorense and H. japonicum extract, respectively. The H. mysorense exhibited stronger free radical scavenging activity as evidenced by the low IC50 values in DPPH (3.35 µg/ml), ABTS (29.5 µg/ml), H2O2 (58 µg/ml), and Lipid peroxidation (13 µg/ml) methods, and H. perforatum exhibited its potent activity against ABTS (28.5 µg/ml), DPPH (7.5 µg/ml), and H. japonicum exhibited its H2O2 scavenging activity at 49 µg/ml. The significance of the obtained values are distinguished when compared with the standards (Rutin) used. The results strongly suggest the exploration of effective lead from hypericum species will be alternative choice for the treatment of pathologies caused in the consequences of excess free radical production.