Anti- hyperglycemic effect of aqueous extract of Kappaphycus alvarezii (Doty) Doty ex. P. Silva in alloxan-induced diabetic rats

The intake of food and control of blood glucose levels are very important in diabetic patients. α-Glucosidase inhibitors are a cost-effective means to prevent the progression of diabetes. To find a natural inhibitor from seaweed with anti-hyperglycemic effects, methanolic extract of a red seaweed, Kappaphycus alvarezii (Doty) Doty ex P. Silva, which contains complex mixtures of various types of bioactive compounds which have a hypoglycaemic effect was evaluated in alloxan-induced diabetic rats by using two different doses (200 and 400 mg kg−1 body weight). Blood glucose, glycosylated haemoglobin, haemoglobin, serum lipids of total cholesterol, triglyceride, high-density lipoprotein cholesterol (HDL-C), phospholipids, low density lipoprotein (LDL) and plasma insulin were examined in control and seaweed extract-treated experimental rats. The aqueous extract was orally administered for 28 days. The results showed that the aqueous extract of K. alvarezii significantly (p < 0.05) reduced blood glucose level and restored glycosylated haemoglobin and plasma insulin. These results demonstrate that K. alvarezii can be used as a health food and has strong anti-diabetic effects in vivo; thus, it may have beneficial properties in the prevention of diabetes and could be useful in the development of anti-diabetic drugs.