Arsenic induced oxidative stress and the role of antioxidant supplementation during chelation: a review.

Arsenic is a naturally occurring metalloid, ubiquitously present in the environment in both organic and inorganic forms. Arsenic contamination of groundwater in the West Bengal basin in India is unfolding as one of the worst natural geoenvironmental disaster to date. Chronic exposure of humans to high concentration of arsenic in drinking water is associated with skin lesions, peripheral vascular disease, hypertension, Blackfoot disease and high risk of cancer The underlying mechanism of toxicity includes the interaction with the sulphydryl groups and the generation of reactive oxygen species leading to oxidative stress. Chelation therapy with chelating agents like British Anti Lewisite (BAL), sodium 2,3-dimercaptopropane 1-sulfonate (DMPS), meso 2,3 dimercaptosuccinic acid (DMSA) etc., is considered to be the best known treatment against arsenic poisoning. The treatment with these chelating agents however is compromised with certain serious drawbacks/side effects. The studies show that supplementation of antioxidants along with a chelating agent prove to be a better treatment regimen. This review attempts to provide the readers with a comprehensive account of recent developments in the research on arsenic poisoning particularly the role of oxidative stress/free radicals in the toxic manifestation, an update about the recent strategies for the treatment with chelating agents and a possible beneficial role of antioxidants supplementation to achieve the optimum effects.

Effects of chelation therapy on hepatic glutathione, lipid peroxidation and phospholipid contents in lead-poisoned rats.

Hepatic lipid peroxidation, glutathione and phospholipid contents of homogenate prepared from the liver of lead-intoxicated male rats treated with 0.3 m mol/kg CaNa2EDTA and DMSA for 8 weeks, either alone or in combination, were investigated. A significant increase in hepatic malondialdehyde (MDA) and a reduction in glutathione levels was noticed. While a marginal decrease in phosphatidyl choline (PC) level was noticed, no effect on phospholipid contents was seen. Treatment with all the three chelating agents elicited decrease in PC level. DMSA alone was partially effective in restoring lead-induced altered hepatic glutathione and MDA levels. Combined treatment may have an adverse effects on hepatic tissue and does not seem to produce immediate recoveries in the lead-induced hepatic damage.