Toxicological Effect of Green Tea (Camelia sinensis) on Haematological Parameters in Wistar Rats

Introduction: Green tea, derived from the leaves of Camellia sinensis, has gained significant attention due to its potential health benefits. It contains various bioactive compounds, such as polyphenols, flavonoids, and catechins, which have antioxidant, anti-inflammatory, and anticancer properties. Despite its widespread consumption and positive reputation, limited information is available regarding the potential toxicological effects of green tea. In this study, the toxicological impact of green tea extract on haematological parameters was investigated using Wistar rats as an animal model. Method:  Forty-eight adult male rats were randomly divided into four groups (n=12 per group). The control group received a vehicle solution, while the treatment groups were orally administered different doses of green tea extract (low dose: 100 mg/kg, moderate dose: 200 mg/kg, high dose: 400 mg/kg) once daily for 28 consecutive days. Haematological analysis was performed at baseline (day 0) and on days 7, 14, 21, and 28 of the study. Blood samples were collected from the retro-orbital plexus under light isoflurane anaesthesia, and various haematological parameters were assessed using automated Hematology analyzers. Results: The results of the haematological analysis showed that the administration of green tea extract did not significantly affect haemoglobin levels, packed cell volume, red blood cell count, eosinophil count, lymphocyte count, and neutrophil count compared to the control group throughout the study period. However, the white blood cell (WBC) count and its differential count exhibited some variations among the treatment groups. The low and moderate doses of green tea extract resulted in a slight increase in the WBC count compared to the control group, although the difference was not statistically significant. On the other hand, the high dose of green tea extract led to a slight decrease in the WBC count compared to the control group. Regarding platelet count, the low and moderate doses of green tea extract resulted in a significant increase compared to the control group. In contrast, the high dose of green tea extract caused a significant decrease in platelet count. Conclusions: Based on the findings of this study, it can be concluded that the administration of green tea extract did not have significant adverse effects on the assessed haematological parameters in Wistar rats, except for some minor variations in the WBC count and platelet count at higher doses. These results suggest that green tea consumption may not cause significant haematological toxicity in rats. However, further studies are warranted to evaluate the long-term effects and safety of green tea consumption in humans.