Context: Gongronema latifolium Benth (Asclepiadaceae) has been highly utilized in controlling diabetes mellitus traditionally in the eastern part of Nigeria. Objectives: Antihyperglycaemic and related gene expressions of aqueous extract of Gongronema latifolium leaf in alloxan-induced diabetic rats. Materials and methods: Forty-eight female Wistar rats were induced intraperitoneally using alloxan (150 mg/kg body weight). The rats were separated into six groups (n = 8) as follows: non-diabetic control, diabetic control, diabetic rats administered 5 mg/kg body weight of metformin, and diabetic rats administered 6.36, 12.72 and 25.44 mg/kg body weight (ethnobotanical doses) of G. latifolium orally daily. On the 14th day, the animals were sacrificed and different antihyperglycaemic parameters were evaluated as well as its related gene expressions. Results: Diabetic rats administered three doses of aqueous extract of G. latifolium significantly (p < 0.05) lowered the fasting blood glucose, glycated haemoglobin, serum lipid profiles, lipid peroxidation (5.62-1.2 μ/mg protein) levels, as well as gene expression of glucose-6-phosphatase in alloxan-induced diabetic rats. There was a significant (p < 0.05) increase in the liver glycogen content (16.23-112.5 mg glucose/2 g), antioxidant enzymes activities, glucose transporter (GLUT-2 and GLUT-4) levels and relative gene expression of hexokinase in diabetic rats administered different doses of aqueous extract of G. latifolium. Discussion and conclusions: It can be deduced that the aqueous extract of G. latifolium leaf at these doses may be useful in managing diabetes mellitus and its associated complications. Therefore, this extract may be a potent antidiabetic agent in clinical therapy in the future.
Keywords: Diabetes mellitus; GLUT-4; ethnobotanical doses; hexokinase GLUT-2; intraperitoneal; lipid peroxidation.