Objective
To evaluate the histopathological and biochemical effects of green tea extract on the liver tissues of high-fat diet and streptozotocin diabetic female rats.
Methods
Eighty adult female rats weighing 150–200 g were taken for the study and divided into four groups: group I (control nondiabetic group), group II (high-fat diet and nondiabetic), group III (high-fat diet and diabetic), and group IV (high-fat diet and diabetic, treated with green tea extract with a concentration of 1.5% in drinking water for 4 weeks), with each group comprising 20 rats (n = 20). Non-insulin-dependent diabetes was induced by a combination of high-fat diet and single intraperitoneal injection of streptozotocin (25 mg/kg body weight). Biochemical estimation of
fasting blood glucose, fasting insulin (FINS), homeostasis model assessment of insulin resistance (HOMA-IR) index, and plasma alanine transaminase was carried out. The livers of the rats were collected for examination of clinical biochemistry,
which includes measuring levels of tissue malondialdehyde (MDA) and reduced gluthione (GSH), and were studied histopathologically by light and electron microscopy.
Results
Body weight, FINS, and the HOMA-IR index were increased in the high-fat diet and nondiabetic group. Body weight, fasting blood glucose, FINS, and the HOMA-IR index were increased in the high-fat diet and diabetic group, but were significantly reduced in the high-fat diet and diabetic group treated with green tea extract. The level of MDA was significantly increased, whereas the level of GSH was significantly decreased in the liver of high-fat diet and diabetic rats; however, the level of MDA was significantly decreased, whereas the level of GSH was significantly increased in the liver of the high-fat diet and diabetic rats treated with green tea extract. Liver histopathology of non-insulin-dependent diabetes rats showed pathological changes. However, treatment with green tea extract attenuated the histopathological changes and corrected the biochemical parameters mentioned above.
Conclusion
Green tea extract could potentially attenuate the hepatic injury induced by high-fat diet and streptozotocin as it has the capacity to scavenge free radicals, protect against oxidative stress, improve antioxidant enzyme activities, and exert an antidiabetic effect.
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