Ethanol Extract of Purple Sweet Potato Tubers (Ipomoea batatas L) Decreases Blood Glucose and Increase Total Antioxidant Level in Rats with High Glucose Intake

High blood glucose level can increase the production of free radicals and the AGEs. Flavonoids from fruits and vegetables can prevent that events because they have antioxidant and hypoglycemic effects. The aim of this study was to examine possible hypoglycemic and antioxidant effect of the ethanol extract of purple sweet potato tubers. Subject of this study were 20 male adult rats divided into 4 groups with randomized pre-test and post-test control group design. Before treatment, blood samples were collected from retro-orbital sinus of all rats for blood glucose, MDA and total antioxidant measurement as pre-test data. After pre-test, group 1 (control group) rats were given normal diet without ethanol extract of purple sweet potato tubers. Group 2, 3, and 4 rats were given normal diet and ethanol extract of purple sweet potato tubers 1 cc/day, 2 cc/day, 4 cc/day, respectively, for one week. After one week of treatment, treatment groups were given single dose of high glucose intake. Over 1, 2, and 3 hours of treatment with high glucose, the blood samples were collected for post-test examination. The data were then analysed by one way anova and paired-t test, and the result showed a significant increase of blood glucose and MDA in group 1 (p < 0,01), significant decrease of total antioxidant in group 1 (p < 0.01). In group 3, all of the parameters were different with group 1 and group 2 (p < 0.01). In group 4, MDA decreased significantly after treatment and the total antioxidant was increased significantly (p < 0.01). From these findings, it can be concluded that ethanol extract of purple sweet potato tubers can maintain the blood glucose level within normal limit, prevent the increase of MDA, and increase total antioxidant of the blood after high glucose intake in rats. The effective dose of the extract in this research was medium dose.