Terminalia catappa aqueous extract reduces hyperglycaemia and oxidative stress in diabetic-hypercholesterolemic rats.

Background: Terminalia catappa is an important medicinal plant. Plants from the genus Terminalia have been reported for antidiabetic effects.

Objective: To study effect of Terminalia catappa leaves aqueous extract in type 2 diabetic rats.

Materials and methods: High-fat diet (HFD) and a low dose of streptozotocin (35 mg/kg, i.p.) were used for inducing type 2 diabetes in rats; streptozotocin was injected after two weeks of dietary modification with HFD. HFD was continued throughout the study. Doses of 500 and 1000 mg/kg of aqueous extract of Terminalia catappa were used as a treatment for six weeks. At the end of the study, biochemical and oxidative stress parameters were estimated. Histopathology and immunohistochemistry of pancreatic tissue were performed.

Results: Significant decrease (p < 0.01, p < 0.001) was observed in glucose levels of diabetic animals treated with T. catappa extract at both dose levels when compared with diabetic control group. Treatment with aqueous extract reduced cholesterol levels significantly (p < 0.05). After receiving 1000 mg/kg of extract, the triglyceride level was significantly lowered (p < 0.01) in the diabetic rats. Extract treatment enhanced the insulin sensitivity index (ISI), while insulin levels and HOMA-IR were markedly reduced. Treatment with 1000 mg/kg of extract significantly enhanced the levels of GSH and catalase. Histopathological analysis of the pancreas showed that damage caused by hyperglycemia was prevented in the extract-treated groups. Pancreatic tissue showed an increased expression of SIRT1 in extract-treated animals.

Conclusion: The current study's findings prove that the extract has remarkable antidiabetic effects.