The aim of this study was to determine the haematological changes induced by subchronic glyphosate exposure in Wistar rats and the ameliorative effect of zinc. Sixty adult male and female Wistar rats were used for the study. Twelve of them were used for the LD50 which was evaluated to be 3750 mg kg-1 with clinical signs of respiratory distress, diarrhoea, rough hair coat and subsequently death observed. The remaining 48 rats were divided into six groups of four males and four females each. The agent(s) administered are as follows: Group I (DW), control, distilled water (2 ml kg-1), group II (Z), zinc (50 mg kg-1), group III (G), glyphosate (375 mg kg-1, 10 % of the LD50), group IV (Z + G), zinc (50 mg kg-1) and glyphosate (375 mg kg-1) while group V (GC), glyphosate (14.4 mg kg-1) and group VI (Z + GC), zinc (50 mg kg-1) and glyphosate (14.4 mg kg-1). The treatment regimens were administered orally by gavage once daily for eight weeks. At the end of the study, blood samples were collected and analysed but there were no statistical different (p>0.05) among the treatment groups. However, the haematological parameters were relatively higher in the groups treated with glyphosate alone except the lymphocyte which was relatively low in the glyphosate treated groups compared to the control group. These changes were suggestive of haematological toxicity induced by oxidative stress caused by glyphosate exposure. In conclusion, the alterations in the haematological parameters such as packed cell volume, hemoglobin concentration, total white blood cell count, neutrophils and lymphocyte counts induced by subchronic glyphosate exposure were found to be differentially ameliorated by pre-treatment with zinc.
Ameliorate, Glyphosate, Haematology, Subchronic, Wistar rat, Zinc.