Antioxidant effect of ethanolic seed extract of Hibiscus sabdariffaIinn (Malvaceae) to alleviate the toxicity induced by chronic administration of Sodium Nitrate on some Haematological parameters in Wistars Rats

The antioxidant activity of ethanolic seed extract of Hibiscus sabdariffa l. was investigated in toxicity induced by chronic administration of sodium nitrate in wistar rats. Twenty-five adult wistar rats were randomly grouped into 5 groups of five rats in each group (n=5). Group I (normal saline); Group II (25mg/kg NaNO3); Group III (25mg/kg NaNO3 + 10mg/kg vitamin C); Group IV (25mg/kg NaNO3 +100mg/kg HS); and Group V (25mg/kg NaNO3 + 200mg/kg HS). All groups received normal saline, Vitamin C and sodium nitrate daily for 60 days respectively. The animals were sacrificed at end of 60 days and blood samples were taken for analysis of total protein and some haematological indices. The toxicity induced by chronic administration of NaNO3 seems to be alleviated by the antioxidant effect Hibiscus sabdariffa l. Tocopherol (Vitamin E) and ascorbic acid (Vitamin C) may likely be responsible for the antioxidant effect of Hibiscus sabdariffa l. since preliminary phytochemical screening reveal the presences of substantial amount in seed oil. Hibiscus sabdariffa l. seed extract are characterized by a very low degree of toxicity with LD50 of above 5000 mg/kg in rats.