POOR ANTEDOTAL EFFECTS OF COPPER AND MANGANESE ON RATS EXPOSSED TO ACUTE DOSE OF DICHLORVOS

Brown Holy*, Oruambo F and Kenanagha B

ABSTRACT

Aim: This study examined the antidotal effect of copper and manganese as an alternative to atropine sulphate in dichlorvos toxicity. Background: Acute pesticide poisoning is a major public health concern today in developing countries. Studies have shown the importance of antioxidants in health and disease that they could help prevent a host of chronic and degenerative disorders that might occur due to adverse effects of chemicals and other toxic agents in the system. Hence the need to assess the antidotal effects of some metals. Methods: Lethal and sublethal doses of dichlorvos was determined in a pilot study to be 18.5mg/kg and 14.5mg/kg respectively. Twenty rats divided into five groups of four albino rats per group were used for the study. Group 1 was given 14.8mg/kg of dichlorvos alone. Group 2 was given 1 ml of atropine sulphate (1.5mg/kg) after injection of dichlorvos (14.8mg/kg). Group 3 was given 1 ml of copper (0.025mg/kg) after the injection of dichlorvos (14.8mg/kg). Group 4 was given 1ml of manganese (0.01mg/kg) after the injection of dichlorvos (14.8mg/kg). Group 5 was given 1ml of manganese (0.025mg/kg) and 1 ml of copper (0.01mg/kg) after the injection of dichlorvos (14.8mg/kg). The symptoms of acute dichlorvos poisoning observed in the rats were straub tail, muscle fasciculation, piloerection, lacrimation, defecation, excessive salivation, whole body tremor, micturition, restlessness, pupil constriction, respiratory distress, gasping, convulsion and death. Results: The haematological result in acute toxicity study showed a statistically significant decrease (p<0.05) in the mean values of the circulating red blood cells (RBC), white blood cells (WBC), haemoglobin (HB), packed cell volume (PCV), and platelet that was dose dependent. Also obtained was a significant dose dependent increase (p<0.05) in the biochemical parameters; aspartate aminotransferase (AST), alanine aminotransferase (ALT), gamma glutamyl transferase (GGT), alkaline phosphatase (ALP), urea and creatinine in the copper, manganese and copper and manganese combined treated rats when compared with the atropine treated and control rats (p<0.05). There was however a significant decrease (p<0.05) in the mean value of serum cholinesterase in all treated groups. These effects were observed to gradually and significantly increase (P<0.05) in the copper, manganese, copper and manganese treated groups and least in atropine treated and control groups. Conclusion: The use of trace elements copper, manganese, and copper and manganese when compared with atropine were not able to reduce the impact of dichlorvos-induced toxicity in the rats.

Keywords: Dichlorvos toxicity, respiratory distress, gasping, convulsion and death