Biochemical Studies of Averrhoa carambola Ethanol Leaf and Fruit Extracts on Alloxan-induced Diabetic Rats

Abstract

The use of herbal medicines has always been an option to treat diseases such as diabetes cancer and other ailments. This study aimed to evaluate the effect of Averrhoa carambola leaf and its fruit ethanol extracts on biochemical parameters and histopathology features. Forty five albino rats were assigned into 9 groups of 5 rats each. Except for the normal control group, others were induced to be diabetic by a single intraperitoneal injection of alloxan. Group 1 (normal control) and Group 2 (diabetic untreated) received water. Group 3 received 2.5mg/kg glibenclamide, Groups 4-9 received graded doses (250mg/kg, 500mg/kg and 750mg/kg) of leaf and fruit extracts of Averrhoa carambola. Treatment lasted 14days. At the end of the treatment, blood samples and organ (pancreas) were collected from the animals for biochemical and histopathological evaluation. Treatment of alloxan-induced diabetic rats significantly (p<0.05) reduced the glucose concentration across all treated groups. Following induction of diabetic mellitus, the serum activities of liver enzymes (Alanine amino transferase, Aspartate aminotransferase and Alkaline phosphatase), low-density lipoprotein cholesterol (LDL-C) and triglyceride were significantly (p<0.05) elevated in diabetic untreated group with corresponding reduction in serum protein, albumin and high-density lipoprotein cholesterol (HDL-C) compared to the normal control and treated groups. However, the fruit extracts exhibited a high increase in urea and creatinine levels especially at dose of 750mg/kg body weight when compared with the leaf though not significantly higher than the diabetic untreated group. From histopathology studies, the groups treated with the leaf extract of Averrhoa carambola showed greater structural improvement and an increase in pancreatic islet cells. Therefore this study showed that although ethanol extracts of Averrhoa carambola leaf and fruit have antidiabetic properties, the leaf extract possesses more antidiabetic effect.