ABSTRACT
Research has demonstrated that Camellia sinensis (Green Tea) exhibits various healthpromoting properties, including anticarcinogenic, anti-inflammatory, antimicrobial, and antioxidant effects. It has shown potential benefits in conditions such as cardiovascular disease, diabetes, weight management, and neurological health. While some studies have suggested a possible association between green tea consumption and liver damage, these claims have been contested by several articles, contributing to a rising trend in green tea consumption. The present study aims to investigate potential alterations in serum liver function indices following the ingestion of Camellia sinensis (Green Tea) aqueous extract in Wistar rats using a chronic exposure model. The study involved 5 experimental groups (A, B, C, D, and E) and a control group, with four rats per group. Rats in the experimental groups (A-E) received daily oral doses of green tea aqueous extract at doses of 250, 500, 1000, 2000, and 4000 mg/kg body weight, respectively, for a duration of 28 days. The findings revealed a significant decrease in body weight among Wistar rats in groups B (500 mg/kg), C (1000 mg/kg), D (2000 mg/kg), and E (4000 mg/kg) by the fourth week compared to the control group. Furthermore, there was a notable decrease in total protein and serum albumin levels in groups B, C, and D compared to the control. Group C (1000 mg/kg) exhibited statistically significant elevations in liver function indicators including ALT, AST, ALP, and GGT levels compared to the control group. Total and direct bilirubin levels were significantly increased in groups B (500mg/kg), C (1000ng/kg), and D (2000mg/kg)’ compared to the control group. Additionally, significant alterations, including inflammatory cell infiltration, steatosis, coagulative necrosis, nuclear degeneration, oedema, and mild distortion of hepatic lobular architecture, were observed in the liver histology slides of groups C (1000mg/kg), D (2000mg/kg) and E (4000mg/kg) compared to the control. The hepatotoxic effects observed may be linked to the elevated levels of catechins present in green tea, as these compounds have been associated with oxidative stress that can lead to damage to liver cells. According to the results of the present study, the no-observed-adverseeffect level (NOAEL) for the green tea extract was established at 250 mg/kg body weight per day. Subsequent studies should investigate the mechanisms driving the observed hepatotoxic effects of green tea and explore their clinical implications.
