Evaluation of the Effects of Green Tea (Camellia sinensis) on Markers of Liver Function and Liver Histology in Wistar Rats

Background: Green tea is rich in flavonoids and catechins, compounds reported to have antioxidant, anti-inflammatory, and anticancer properties. However, there is a need to evaluate the effects of green tea on vital organs like the liver. This study aimed to investigate the effects of Camellia sinensis on markers of liver function, and liver histology in Wistar rats. Methods: Forty-eight adult male Wistar rats were divided into four equal groups and orally administered 250mg/kg, 500mg/kg and 1000mg/kg of Camellia sinensis extract or 1ml of distilled water for up to 28 days. AST, ALT, ALP, TP, ALB, TB, and CB levels were measured at various time points. Effect on liver histology was also assessed using haematoxylin and eosin staining. Results: Camellia sinensis had varying effects on biomarkers of liver injury in a dose-dependent manner. Higher doses (500mg/kg and 1000mg/kg) of Camellia sinensis led to significant increases in AST, ALT, and ALP levels when consumed for up to 21 days. TP and ALB levels were not significantly altered. TB levels significantly increased in the highest dose group while CB levels did not significantly change at any time point studied. Also, higher doses of Camellia sinensis were associated with the development of fatty liver and mild inflammation from the histology. Conclusion: Camellia sinensis extract at low dose may not be harmful to the liver, however, the potential toxicity of green tea on the liver (at higher doses) should be further studied. Moderate use of green tea is therefore, recommended to ensure its safe and beneficial effects on liver health.