Microscopic Evaluation of the Use of a Combination of Vitamin C and Activated Charcoal as Ameliorating Agent against Paraquat-induced Hepatotoxicity

Abstract

Background: Paraquat is a highly toxic, non-selective herbicide that induces severe oxidative stress and multiorgan damage, particularly affecting the liver, lungs, and kidneys, with high mortality in cases of acute poisoning. Owing to the lack of a specific antidote, antioxidant therapy such as Vitamin C and toxin adsorption with activated charcoal have been explored as potential protective strategies against paraquat-induced hepatotoxicity. Aims: The study aims to evaluate the ameliorative effect and the safety of Vitamin C/ Activated Charcoal combination on Paraquat-induced hepatotoxicity. It is also to evaluate the safety of this combination at this dosage and duration, on hepatocytes. To investigate the relationship between the level of tissue damage with the duration of paraquat exposure. To investigate the synergistic effect of the combination of Vitamin C and activated charcoal, on clinical manifestations associated with oral paraquat toxicity in Wistar rats. Study Design: This is an experimental study. Place and Duration of Study: National Veterinary Research Institute, Vom, Nigeria, 2025. Methodology: A total of 40 female Wistar rats, aged eight weeks and weighing between 150 and 200 g, were utilised in the present study. The animals were randomly allocated into four experimental groups, each comprising ten rats. Group I (normal control) received 1 ml of normal saline orally once daily for 28 consecutive days. Group II was administered paraquat at a dose of 50 mg/kg body weight, dissolved in 1 ml of distilled water, once daily for 28 days. Group III received paraquat at 50 mg/kg body weight daily, followed after a 5-minute interval by 1 ml of a combination consisting of vitamin C (250 mg/kg body weight) and activated charcoal (0.175 g/kg body weight) suspended in distilled water, administered once daily for 28 days. Group IV was treated with 1 ml of the combination of vitamin C (250 mg/kg body weight) and activated charcoal (0.175 g/kg body weight) in distilled water once daily for the same duration. All animals were monitored weekly for clinical signs and any observable changes in general condition. Liver tissues were harvested at weekly intervals from randomly selected animals within each group for histopathological processing and microscopic evaluation. Histopathological assessment was conducted through detailed examination of tissue morphology, with particular emphasis on both intracellular and extracellular alterations and the manifestation of pathological changes. 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, Liver sections of groups 1 and 4 remain histologically normal throughout the experiment. Group 2 liver shows massive degeneration and hepatic haemorrhage. Group 3 shows microscopically normal tissue, with mild hypertrophy and mild central vein congestion on days 21 and 28. This has shown that this combination is effective in ameliorating paraquat-induced hepatotoxicity. It has also shown that that at this dosage, Vitamin C and activated charcoal is safe on the hepatocytes.