The Antioxidative Activities And The Protective Effects On DNA Damage Of Constituents In Grape Seed

The constituents in grape seeds are mainly polyphenolic compounds with significant antioxidative activities, which are involved in many pharmacological effects. In the present studies, the effects of the constituents in grape seeds on lipid peroxidation, by estimating MDA formation, and on DNA damage induced by oxidative stress, by using single cell gel electrophoresis assay (SCGE), were investigated.It was shown that the constituents in grape seeds including resveratrol, proanthocyanidins, catechins and its polymers, monophenols and polyphenols (1.0, 10.0 mg/L), could significantly inhibit the formation of LPO in rat liver homogenate m vitro. Resveratrol, proanthocyanidins and the low-polymers of catechin had more significant effects and the lower IC50 than others. Furthermore, all constituents could inhibit the formation of LPO in rat liver homogenate induced by hydroxyl radical in Fenton system (Fe2+/H2O2) in vitro.The results of SCGE were shown that resverstrol and proanthocyanidins (5, 50 mg/kg, i.p.), given alone, had no significant effect on mouse lymphocyte DNA. Potassium dichromate (10, 20, 30, and 40 mg/kg, i.p.) could induce a siginificant DNA damage in mouse lymphocyte 20 minutes after injection. Resveratrol and proanthocyanidins, at the dose of 5 and 50 mg/kg (i.p.), significantly inhibited the DNA damage induced by potassium dichromate (20 mg/kg, i.p.) in mouse lymphocytes and hepatocytes. Moreover, acute ethanol (2.0 g/kg, i.p.) induced lymphocyte DNA damage, which was maximal at 20 min after administration. The DNA damage almost recovered at 180 min.Resveratrol and proanthocyanidins (5 and 50 mg/kg, i.p.) showed the obviously inhibiting effects on the DNA damage in mouse lymphocytes and hepatocytes induced by acute ethanol administration (2.0 g/kg, i.p., 20 min).The anti-SARS prescription II, III, and IV recommended by Chinese Ministry of Health, at the doses of 1/3,1 and 3 times of the clinical dose (3 days, P.O.), had no significant effect on DNA in mouse lymphocytes. However, the prescription I, V, and VI (also 1/3, 1, and 3 tunes of the clinical dose, 3 days, p.o.) showed the obviously harmful effects on mouse lymphocyte DNA. Resveratrol (50, 100, and 200 mg/kg, 3 days, p.o.) and vitamin C (50, 100, and 200 mg/kg, 3 days, p.o.) could dose-dependently restore the DNA damage induced by prescription I and VI (clinical dose, 3 days, p.o.).In conclusion, these results gave the further evidence that the constituents in grape seed had good activities of anti-LPO formation and firstly demonstrated that these compounds protected cellular DNA damage induced by the noxious substances.