[The antioxidant activity of wild jujubi, crataegus and grape in vitro]

Two oxidative damaging systems, Fe(2+)-Cys and tert-butyl hydroperoxide, were used to induce the production of malondialdehyde (MDA) in rat liver microsome and erythrocytes. The inhibition rate of wild jujubi, crataegus and grape juice at the concentration of 2.5-3.3 mg/ml to Fe(2+)-Cys system on the production of MDA were 46.2%, 98.3% and 99.1% respectively. The inhibition rate of jujubi (8.3 mg/ml), crataegus (13.9 mg/ml) and grape (55.6 mg/ml) to tert-butyl hydroperoxide were 38.7%, 38.7% and 58.5% respectively. The capability of scavenging O2.- and .OH was measured by ESR technique. It was found that the capability of these juices to eliminate O2.- and .OH generated by the xanthine/xanthine oxidase system and H2O2-FeSO4 system was strong. The elimination rate of jujubi (50 mg/ml), crataegus (50 mg/ml) and grape (134 mg/ml) to O2.- were 84.0%, 85.8% and 74.7% respectively and the rate to .OH were 96.7%, 97.8% and 86.3% respectively. The results indicated that these three fruits bear antioxidant activity.