Antioxidant effects of Vitamins C and E on phenylhydrazine-induced haemolysis in sprague dawley rats: Evidence for a better protection by Vitamin E

BACKGROUND: Phenyldrazine (PHDZ) provokes acute haemolysis and generates free radicals that are known to be involved in the toxicity of the drug. Vitamin C and E have been ascribed beneficial roles in many acute haemolytic states and oxidative stress. OBJECTIVE: The present study was designed to assess the antioxidant effect of vitamin C and E on PHDZ- induced haemolysis in SD rat in-vivo and ex-vivo. METHOD: Rats treated for weeks with oral vitamin E (500mg/kg/day, n=6), oral vitamin C (100mg/kg/day, n=6) and control rats, which received tap water; were monitored for peripheral blood parameters and haemolytic activity of erythrocytes at Baseline, 48 hours and 1 week respectively after intraperitonial administration of PHDZ (15mg/kg/day for 7 days). Osmotic fragility as well as organ weights were determined 1 week after PHDZ. Dose-dependent effects of vitamins C and E on haemolysis were determined at the end of 120 min incubation of rat RBC with the vitamins in phosphate-buffered-saline. RESULTS: Hb and PCV were better preserved in rats pre-treated with the antioxidants. The spleenomegaly, cardiomegaly and hepatomegaly associated with PHDZ treatment were significantly reduced in antioxidant pre-treated rats (P<0.001). reduction in cardiac weight was more marked in vitamin E group (0.56+/- 0.02g vs. 0.72+/-0.03g; n=6; P<0.01; vitamin E vs. PHDZ) compared to vitamin C (0.69+/-0.02g vs. 0.72+/-0.03g; n=6; P>0.05; vitamin C compared to PHDZ). RBC of vitamin E group exhibited better resistance to osmoticlysis (P<0.001). at higher doses (400-500mg/L), vitamin C caused significant haemolysis both in the absence (P<0.001) and presence of PHDZ (P<0.001). Vitamin E abolished the long tail of the osmotic fragiligram. CONCLUSION: The result of this study suggests that compared to vitamin C, vitamin E may better protect RBC against haemolysis induced by oxidative stress.