Ascorbic acid protects male rat brain from oral potassium dichromate-induced oxdative DNA damage and apoptotic changes: the expression patterns of caspase-3, P 53, Bax, and Bcl-2 genes.

Our study designed to study the potential of potassium dichromate (K2Cr2O7) oral exposure to induce damage in male rat brain and to compare the possible protective role of vitamin C (VC) either pre and/or concurrent supply against (K2Cr2O7) induced changes. Thirty male rats were divided into five groups. First control group received distilled water (C), second received 120 mg/kg b.wt (VC), third received 25 mg/kg b.wt K2Cr2O7 (Cr), fourth group received VC together with K2Cr2O7 by the same former doses (VC + Cr), and the fifth group received the same oral doses of VC 2 weeks prior to and along with K2Cr2O7 for 6 weeks (VC + Cr pro/co treated). The obtained results revealed that K2Cr2O7 induced a significant decrease in cholinergic activity, glutathione reductase GR activity, reduced glutathione content GSH and ATP levels. Furthermore, K2Cr2O7 induced a significant increase in oxidative DNA damage indicated by 8-hydroxy 2'-deoxyguanosine (8OH2'dG) and formation of apoptotic DNA ladders, significant increase in malondialdehyde (MDA), protein carbonyl, and lactate dehydrogenase enzyme. Increased mRNA expression of pro-apoptotic genes, including caspase-3, p53, and Bax, unlike Bcl-2 expression, was decreased. K2Cr2O7 increased caspase-3 and decreased Bcl-2 immuno-labeling. VC supply noticeably ameliorates K2Cr2O7-induced changes which were more significantly in VC pro and concurrent supplement rather than VC concurrent supply only. Finally, it is concluded that K2Cr2O7 oral administration induced oxidative apoptotic changes in rat brain and confirms the usefulness of VC pre and concurrent supply for the amelioration of K2Cr2O7-induced events more significantly than VC concurrent supply only.