ABSTRACT

Free radicals generation have been linked to various diseases mostly cancer and heart diseases. Excessive generation of free radicals leads to oxidative stress and lipid peroxidation. However, research has shown that antioxidant defense mechanism can effectively scavenge these free radicals and hence protect body against the deleterious effect caused by free radicals generation. The aim of the present study was to investigate the antioxidants (glutathione peroxidase, superoxide dismutase and catalase) and haematological (red blood cell, white blood cell, pack cell volume and haemoglobin) indices of monosodium glutamate (MSG) induced male Wistar albino rat treated with methanol extract of A. gangetica leaves. The acute toxicity study was carried out using 18 male Wistar albino mice while 36 male Wistar albino rats were used for the effects of the extract on antioxidant and haematological indices. The rats were grouped into 9 groups of 4 rats each. Group 1 served as normal control and received 2 ml/kg b. wt. of distilled water for 14 days. Group 2 received a suspension of 8 g/kg b. wt. of MSG on day 7 and 14 and served as positive control. Group 3 received a suspension of 8 g/kg b. wt. of MSG and treated with 200 mg/kg b. wt. of sylimarin for 14 days. Group 4 and 5 received 200 and 500 mg/kg b. wt. of A. gangetica leaves respectively for 14 days. Group 6 and 7 received 200 and 500 mg/kg b. wt. of A. gangetica leaves respectively for 7 days prior to MSG induction on the 7th and 14th day respectively and continued receiving the extract for the next 7 days. Group 8 and 9 received a suspension 8 g/kg b. wt. of MSG on the first day and 14th day and was treated with the 200 and 500 mg/kg b. wt. respectively of methanol extract of A. gangetica leaves. The study showed that administration of MSG caused a significant (p > 0.05) increase in the level of serum malondialdehyde (MDA) concentration and consequently resulted to a significant (p < 0.05) decrease in the antioxidant enzyme activities (GPx, SOD and CAT) and haematological indices (RBC, Hb and WBC) respectively. On the other hand, the study also showed that dose dependent administration of methanol extract of A. gangetica leaves resulted to a significant (p > 0.05) increase in antioxidant enzyme activities and also was able to restore the haematological indices to levels comparable to the normal control. The findings from this study suggest that methanol extract of A. gangetica leaves were effective in mopping up the free radicals generated following the MSG induction. This could be attributed to the antioxidant-rich components of the extract.