**Author details**

1 ml *Allum cepa* solution (0.4 g A. cepa/rat) has been shown to increase the fasting serum highdensity lipoprotein levels and caused reduction of hyperglycaemia in streptozotocin (STZ) diabetic rats [71]. The hypoglycaemic and hypolipidaemic activities of A. cepa were associated with antioxidant activity via decrease superoxide dismutase (SOD) activity while no increased lipid hydroperoxide and lipoperoxide concentrations in diabetic rats treated with A. cepa [71]. In another experiment, onion juices exerted antioxidant and antihyperglycemic effects on alloxan-induced diabetes and consequently ameliorated liver and renal damage associated

Flavonoids from *Ipomoea batatas* leaf (FIBL) was reported to have anti-diabetic activity on alloxan-induced diabetic mice [73]. FIBL treatment (50, 100, and 150 mg/ kg body weight) for 28 days resulted in a significant decrease in the concentration of fasting blood glucose (FBG), total cholesterol (TC) and triglyceride (TG) in diabetes mellitus mice [73]. Also, FIBL signifi‐ cantly increased body weight (bw) and serum high-density lipoprotein cholesterol (HDL-c) level [73]. Stress and inflammation-related p38 mitogen-activated protein kinase activity and tumour necrosis factor-α production of diabetic rats were significantly depressed by *Ipomoea batatas* administration [74]. Similarly, histological examination also revealed improvement of pancreatic β-cells mass after treatments with *Ipomoea batatas* [74]. *Blighia sapida* has also been reported to have several ethnomedicinal uses of which various preparations and extracts have been made for the treatment of diseases such as dysentery, epilepsy, yellow fever and diabetes [75]. Saidu *et al*. [76] recently reported that *Anacardium occidentale* leaves at 300mg/kg body weight showed significant hypoglycaemic activity in alloxan-induced diabetic rats comparable

Diabetes mellitus is a metabolic disorder in the endocrine system. It is known to be a dreadful disease that is found in all parts of the world with a serious threat to the health of mankind. Diabetes mellitus affect most of the people of both developed and developing countries. There are lots of synthetic drugs that have been used to control and to treat diabetic patients with partial recovery from this dreaded disease. Alternative to these synthetic agents, plants provide a potential source of hypoglycemic drugs and are widely used in several traditional systems of medicine to prevent diabetes. Several medicinal plants have been investigated for their beneficial use in different types of diabetes. Several phytonutrients have been identified from medicinal plants and this presents an exciting opportunity for the development of new types of therapeutics for diabetes mellitus. Most abundant phytonutrients present in medicinal plants are the alkaloids, terpenes, and phenolics. Phytomedicine has been used since ancient time in many parts of the world where access to modern medicine is limited. Despite consid‐ erable progress in the treatment of diabetes by oral hypoglycemic agents, search for newer drugs continues because the existing synthetic drugs have several limitations as shown in table 1. The treatment of diabetes with synthetic drugs in the developing countries is expensive due to poverty and lack of access to Medicare. Hence, phytotherapy has significant role to play in

with alloxan toxicity [72].

106 Antioxidant-Antidiabetic Agents and Human Health

to the standard drug-metformin.

**13. Conclusion**

A.A. Oyagbemi1,2, M. Salihu3 , O.O. Oguntibeju4 , A.J. Esterhuyse4 and E.O. Farombi1\*

\*Address all correspondence to: olatunde\_farombi@yahoo.com

1 Drug Metabolism and Toxicology Unit, Department of Biochemistry, College of Medicine, Nigeria

2 Department of Veterinary Physiology, Biochemistry & Pharmacology, University of Iba‐ dan, Nigeria

3 Biochemistry Unit, Department of Biological Sciences, College of Natural Sciences, Al-Hik‐ mah University, Ilorin, Nigeria

4 Oxidative Stress Research Centre, Department of Biomedical Sciences, Faculty of Health & Wellness Sciences, Cape Peninsula University of Technology, Bellville Campus, South Africa
