Research: KUIPER and COLLEAGUES,

Listed in Issue 201

Abstract

KUIPER and COLLEAGUES, Linus Pauling Institute, Oregon State University, Corvallis, OR 97331, USA evaluated the efficacy of vitamin C supplementation in decreasing biomarkers of lipid peroxidation in nonsmokers and in cigarette smokers.

Background

The lack of suitable biomarkers of oxidative stress is a common problem for antioxidant intervention studies in humans. The authors evaluated the efficacy of vitamin C supplementation in decreasing biomarkers of lipid peroxidation in nonsmokers and in cigarette smokers, a commonly studied, free-living human model of chronic oxidative stress.

Methodology

Participants received ascorbic acid (500mg twice per day) or placebo for 17 days in a double-blind, placebo-controlled, randomized crossover design study. The urinary biomarkers assessed and reported herein are derived from 4-hydroperoxy-2-nonenal (HPNE) and include the mercapturic acid (MA) conjugates of 4-hydroxy-2(E)-nonenal (HNE), 1,4-dihydroxy-2(E)-nonene (DHN), and 4-oxo-2(E)-nonenol(ONO).

Results

Vitamin C supplementation decreased the urinary concentrations of both ONO-MA (p=0.0013) and HNE-MA (p=0.0213) by ~30%; however, neither cigarette smoking nor sex affected these biomarkers. In contrast, vitamin C supplementation decreased urinary concentrations of DHN-MA (three-way interaction p=0.0304) in nonsmoking men compared with nonsmoking women (p<0.05), as well as in nonsmoking men compared with smoking men (p<0.05). Vitamin C supplementation also decreased (p=0.0092) urinary total of metabolites by ~20%.

Conclusion

Thus, HPNE metabolites can be reduced favourably in response to improved plasma ascorbic acid concentrations, an effect due to ascorbic acid antioxidant function.

References

Kuiper HC, Bruno RS, Traber MG, Stevens JF. Vitamin C supplementation lowers urinary levels of 4-hydroperoxy-2-nonenal metabolites in humans. Free Radical Biology & Medicine. 50(7): 848-53, Apr 1 2011. Other ID Source: NLM. NIHMS264722 [Available on 04/01/12] Source: NLM. PMC3046321 [Available on 04/01/12].

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