Croton lobatus fruits aqueous extract exhibited anti-type 2 diabetic activity in high-fat diet and low-dose streptozotocin-induced type 2 diabetic male Wistar rats
摘要
The prevalence of type 2 diabetes mellitus (T2DM), a long-term medical, arising from partial or complete loss of pancreatic islet β cell function, has been on steady increase globally. This high prevalence has therefore necessitated the need to screen for alternative and complementary management options in medicinal plants. This study was, therefore, designed to screen aqueous extract of Croton lobatus fruits (AECLF) for anti-type 2 diabetic mellitus activity using a high-fat diet (HFD) and low-dose streptozotocin (STZ). Secondary metabolite constituents of Croton lobatus fruits were determined using standard methods. Thirty-six male rats weighing 164.70 ± 10.10 g were randomly assigned into six groups: A-F. Animals in group A (non-diabetic) received 0.5 mL of distilled water (DW) orally, once daily for 14 days, while those in groups B, C, D, E, and F which were made diabetic (by intraperitoneal injection of 30 mg/kg body weight of STZ, twice after being placed on HFD for 14 days) also received 0.5 mL of DW, 100 mg/kg body weight of metformin, 6.5, 13, and 26 mg/kg body weight of AECLF, respectively. The results revealed that Croton lobatus fruits contained phenolics (595.33 mg/100 g), flavonoids (183.36 mg/100 g) and cardiac glycosides (0.05 µg/100 g). The combination of the HFD and STZ significantly (p < 0.05) increased total body weight, blood glucose level, oral glucose tolerance, serum urea, creatinine, uric acid, total cholesterol, triglycerides, low-density lipoprotein-cholesterol, atherogenic index, white blood cells, and hepatic hexokinase activity, whereas the pancreas/body weight ratio, levels of liver glycogen, high-density lipoprotein-cholesterol, K+, Na+, packed cell volume, platelets, red blood cells, haemoglobin, and serum insulin reduced significantly (p < 0.05). In contrast, the 6.5 and 13 mg/kg body weight of AECLF significantly reversed and/or ameliorated the HFD and STZ treatment-related changes in the levels of these parameters in a manner similar to that of metformin-treated diabetic rats. The study concluded that aqueous extract of Croton lobatus fruit has anti-type 2 diabetic activity and could be explored against T2DM after necessary toxicological evaluations and clinical trials.