Antioxidant activities of compounds isolated from Dalbergia odorifera T. Chen and their inhibition effects on the decrease of glutathione level of rat lens induced by UV irradiation

Four compounds were isolated from the root of Dalbergia odorifera T. Chen and identified by chemical and spectroscopic methods as 2′-O-methyl-isoliquiritigenin (1), odoriflavene (2), 5′-methoxy-vestitol (3) and formononetin (4). Their antioxidant activities were investigated in lard by the oxidative stability instrument; their inhibitory effects on the decrease of glutathione level of rat lens induced by UV irradiation were studied using a rat lens UV-damage model, and their in vitro cytotoxicity was measured on human SH-SY5Y neuroblastoma cells. Results indicated that all four compounds had obvious antioxidant effects, while none of them showed any synergistic effects on butylated hydroxytoluene or α-tocopherol. When FeCl3 (4.0 μM) was added, the antioxidant activities of the four compounds markedly decreased. The inhibitory effects of compounds 1, 2 and 4 on the decrease of glutathione level of rat lens induced by UV irradiation were comparable to that of α-tocopherol. All four compounds showed cytotoxic activity when evaluated against a SH-SY5Y cell line in vitro.