L-ascorbic acid and α tocopherol supplementation and antioxidant status in nickel- or lead-exposed rat brain tissue.

We evaluated the effect of L-ascorbic acid and alpha-tocopherol supplementation on plasma and whole brain nitric oxide level and antioxidant status in nickel sulfate- or lead acetate- treated male albino rats. Nitric oxide and lipid peroxide levels in whole brain tissue and plasma increased following nickel and lead treatment but significantly returned to near-normal values upon L-ascorbic acid or alpha-tocopherol supplementation. In brain tissue, antioxidant enzymes--superoxide dismutase, glutathione peroxidase, glutathione peroxidase, and catalase--along with the glutathione level decreased significantly after both treatments but significantly improved upon simultaneous supplementation with L-ascorbic acid or alpha-tocopherol. Lead-treated animals showed a greater improvement with alpha-tocopherol, whereas nickel-treated rats showed a greater improvement with L-ascorbic acid. In both groups, combined supplementation with L-ascorbic acid and alpha-tocopherol did not change the percentage improvement in comparison with supplementation with a single vitamin alone.