Biotechnology Journal International

Aims: To investigate the Synergistic ameliorative effect and the safety of Vitamin C/ Activated Charcoal on Paraquat-induced lung histotoxicity and normal lungs of Wistar rats respectively. To investigate the relationship between the level of tissue damage and clinical manifestations with the duration of paraquat exposure.

Place and Duration of Study: National Veterinary Research Institute, Vom, Nigeria, for 28 days.

Methodology: A total of 40 female 8-week-old Wistar rats, weighing between 150 to 200 grams were used, the rats were randomly assigned into 4 groups, of 10 rats each. Group 1 rats, normal control, received   orally, 1ml of normal saline solution daily for 28 days. Group 2 animals received paraquat solution at 50mg/kg body weight dissolved in 1ml of distilled water once daily, for 28 days. Group 3 animals received paraquat solution at 50mg/kg body weight daily, followed after 5 minutes by 1ml of a combination of a solution of Vitamin C at 250mg/ kg body weight and a suspension of activated charcoal in distilled water at 0.175g/kg body weight, once daily for 28 days. Group 4 animals were administered 1ml of a combination of a solution of Vitamin C at 250mg/ kg body weight and a suspension of activated charcoal in distilled water at 0.175g/kg body weight once daily for 28 days. They were observed weekly. Lung tissue was harvested weekly for histopathology processing and microscopic examination from the groups randomly. The histopathological method applied is tissue morphology assessment and intra as well as extra cellular substances manifestation

Results: Group 1 and 4 animals present with normal physical behavior, water/ feed consumption. Group 2 animals present with severe reduction in feed/ water intake, respiratory distress and other physical abnormalities, which worsened with duration of the experiment. A mortality was recorded on each of days 8, 17 and 25. Group 3 animals present with milder signs of what was observed in group 2, with a mortality on day 23. Microscopically, Lung sections of groups 1 and 4 remain histologically normal throughout the experiment. Group 2 lung sections show massive diffuse eodema and vacuolations in alveolar spaces, indistinct alveolar epithelium, interalveolar septal haemorrhages and profuse infiltration of inflammatory cells in alveolar spaces, with complete loss of tissue architecture, which worsened with duration. Group 3 sections shows mild alveoli septa enlargement from day 7 to day 14, with mild interseptal haemorahes and edema from day 21 to day 28.

Conclusion: Histopathologically, group 2 shows established histotoxicity while group 3 shows amelioration and recovery from toxicity. As the duration of the experiment increases, the ameliorative effect of the dosage of this combination begins to decrease. There is hence, a need, to use graded doses of the combination of vitamin C and activated charcoal, to establish the optimum dose that can withstand long term exposure to paraquat toxicity. The normal morphology seen in both group 1 and group 4 has shown that at this dose, the combination of vitamin C and activated charcoal is safe for the animal.