Distribution of Cyclooxygenase-2 (COX- 2) in the Liver of Adult Male Albino Rats after Supplementation of Sodium Arsenite with or without Allium Sativum (Garlic)

Introduction: Arsenic is a toxic carcinogenic metalloid. Environmental exposure mainly occurs from arseniccontaminated drinking water. COX-2 is involved in chronic inflammatory pathologies. Aim of the Work: Investigation of light microscopical, immunohistochemical distribution of (COX-2) in the liver of adult male albino rats and biochemical changes after oral administration of sodium arsenite and effect of garlic supplementation. Materials and Methods: Forty adult male rats were divided into: group I negative control rats. Group II positive control animals received daily garlic orally. Group III Received daily sodium arsenite orally. Group IV received daily sodium arsenite and garlic. Animals were sacrificed after12 weeks. Sera and liver were prepared for light microscopical, immunohistochemical and biochemical studies. Results: In group I, II control rats, the immune-reaction of Cox-2 was negative in hepatocytes. Group-III animals showed structural changes in the form of disruption of the liver cytoarchitecture, inflammatory cells infiltration, small dense nuclei and vacuolated cytoplasm of hepatocytes, excess collagen and reticular fibers in the portal tract and between hepatocytes and strong PAS reaction in hepatocytes. Strong immune-reaction of Cox-2 was detected in inflammatory cells and in cytoplasm of most of hepatocytes even in the vacuolated hepatocytes. In addition to a significant increase in blood glucose and catalase enzyme (natural defence mechanisms against reactive oxygen species induced damage) In group IV rats, garlic partially prevented the structural, immunohistochemical expression of Cox-2 and biochemical changes. Conclusion: Arsenic induced structural, biochemical changes and enhanced Cox-2 expression in the liver of adult male rats. Garlic partially prevented these changes and down-regulated Cox-2 expression, suggesting a beneficial role of garlic supplementation in reducing arsenic toxicity.