Antioxidants as DNA protective compounds: A review of clinical trial studies

Introduction Based on the recent findings, antioxidants are some essential factors that can have major role on the health. The human body naturally has a powerful antioxidant system that its function is to neutralize the oxidative stress caused by reactive oxygen species (ROS) following the natural metabolism of the body. Also external antioxidants can help these proceeds. This review aims at summarizing the effect of different antioxidants on DNA. Methods Our search was carried out in databases and 20 eligible articles were identified. The key words used for the search were: antioxidants in combination of ROS, DNA damage and fragmentation. The effects of antioxidants in preventing damage to DNA and also the amount of damage were checked out in the studies by the following methods: 8-oh-dg, comet assay, mutation analysis, micronucleus assay, DNA base damage products. Results Antioxidants prevent damage to macromolecules, such as DNA and proteins. However, according to available evidences, the effects of some antioxidant compounds such as vitamin c, poly phenols and zinc on the prevention of DNA damage are dose dependent so even using these substances at inappropriate doses can increase DNA damage. In general, the use of antioxidant compounds such as selenium, vitamins E, C and beta-carotene appears to be effective in activation of superoxide dismutase, glutathione peroxidase, protecting DNA damage and preventing certain diseases, such as cancer and vascular disease. Conclusion Although there are different effects of antioxidants on prevention of DNA fragmentation, further studies should be considered to determine the effective dosage in preventing it.