Abstract

The experiments were performed with the aim of investigating the possible ameliorative effects of ascorbic acid and α-tocopherole supplements administered to sodium nitrate-treated rats on total and differential leukocyte counts. Seventy (70) adult Wistar rats, divided into seven groups of 10 rats each were used for the study. They were administered drugs or distilled water orally using a metallic canula between 8.00 to 10.00 am daily for 60 days as follows: Group I (control) received distilled water; Group II received 30 mg/kg NaNO₃; Group III  received 30 mg/kg NaNO₃ + 500 mg/kg AA; Group IV received 30 mg/kg NaNO₃ + 750 mg/kg AA; Group V received 30 mg/kg NaNO₃ + 300 mg/kg vitamin E; Group VI received 400 mg/kg NaNO₃ + 300 mg/kg vitamin E and Group VII received 30 mg/kg NaNO₃ + 500 mg/kg AA + 300 mg/kg vitamin E. At the end of the experiment, the rats were sacrificed and blood was collected for the determination of total and differential leukocyte count. The results showed that sodium nitrate administration induced leukocytosis, which was enhanced by AA administration at both the higher and lower doses as evidenced by increased neutrophil and lymphocyte counts as well as increased monocyte count at the lower dose. Similarly, α-tocopherole at both doses enhanced NaNO₃ toxicity by increasing lymphocyte and total leukocyte counts. In conclusion, co-administration of the two antioxidant vitamins showed negative synergistic effect.

Key words: Ascorbic acid, α-tocopherole, sodium nitrate, leukocytes, rats.