Protective effects of vitamins C and E on the number of micronuclei in lymphocytes in smokers and their role in ascorbate free radical formation in plasma

Abstract

Cigarette smoke is widely believed to increase free radical concentrations causing subsequent oxidative processes that lead to DNA damage and hence, to several diseases including lung cancer and atherosclerosis. Vitamin C is a reducing agent that can terminate free-radical-driven oxidation by being converted to a resonance-stabilized free radical. To investigate whether short-term supplementation with the antioxidants vitamin C and E decreases free-radical-driven oxidation and thus decreases DNA damage in smokers, we determined the frequency of micronuclei in lymphocytes in 24 subjects and monitored the electron paramagnetic resonance signal of ascorbate free radical formation in plasma. Further parameters comprised sister-chromatid exchanges and thiobarbituric acid-reactive substances. Twelve smokers and twelve non-smokers took 1000 mg ascorbic acid daily for 7 days and then 1000 mg ascorbic acid and 335.5 mg RRR-alpha-tocopherol daily for the next 7 days. Baseline concentrations of both vitamins C and E were lower and baseline numbers of micronuclei were higher (p < 0.0001) in smokers than in non-smokers. After 7 days of vitamins C and E, DNA damage as monitored by the number of micronulei was decreased in both, smokers and non-smokers, but it was more decreased in smokers as indicated by fewer micronuclei in peripheral lymphocytes (p < 0.05). Concomitantly, the plasma concentrations of vitamin C (p < 0.001) as well as the ascorbate free radical (p < 0.05) were increased. The corresponding values in non-smokers, however, did not change. Our findings show that increased ascorbate free radical formation in plasma after short-term supplementation with vitamins C and E can decrease the number of micronuclei in blood lymphocytes and thus DNA damage in smokers.

Iron induced genotoxicity: attenuation by vitamin C and its optimization

“…The antimutagenic effect involves an anticlastogenic effect of VC and its capability of decreasing the number of chromatid and chromosomal type aberrations. The lack of a genotoxic effect of ascorbic acid is consistent with other in vivo studies that have demonstrated the anti-oxidant effects of ascorbic acid (Schneider et al, 2001;Lee et al, 1998). As a cofactor in hydrolase and oxygenase enzymes, ascorbic acid maintains iron and other metals in a reduced state.…”

High-dose intravenous vitamin C is not associated with an increase of pro-oxidative biomarkers

“…The supplementation resulted in an increase of both vitamin C and AFR in the plasma with a concomitant decrease of micronuclei in lymphocytes, an established marker for DNA damaging (Schneider et al, 2001). Based on these results, we had no evidence for DNA damage mediated by vitamin C and AFR.…”

Antioxidants rescue stressed embryos at a rate comparable with co-culturing of embryos with human umbilical cord mesenchymal cells

“…A balance between ROS and the amount of antioxidants is essential for the normal development of embryos especially in the laboratory. Numerous studies have demonstrated the antioxidant effects of vitamin C on living cells [25]. Vitamin C was also used to prevent cytogenetic damage to the embryos that were produced by breeding irradiated male and Fig.…”