Comparison of biological activities of ethanol extracts of unripe fruit of bitter melon (Momordica charantia L.) cultivated in Hamyang, Korea

Abstract

To develop health-functional food ingredients for improvement of diabetes, we examined biological activities, including total contents of polyphenols and flavonoids, antioxidant activity, and inhibition of α-glucosidase and pancreatic lipase activities of ethanol extracts from unripe fruit of Momordica charantia L. cultivated in Hamyang, Korea. Ethanol extracts were tested using different ethanol concentrations (0%, 30%, 50%, and 70%) and temperatures (50°C and 70°C). Experimental results showed that total polyphenol and flavonoid contents were achieved concentrations of 7.77 mg/g (tannic acid), 7.66 mg/g (gallic acid), and 10.66 mg/g (rutin). The hydroxyl radical scavenging, ABTS cation radical scavenging, and FRAP activities were 82.19%, 42.82%, and 0.19 under the same conditions, respectively. The highest inhibitory activities of α-glucosidase and pancreatic lipase were achieved in the 70% ethanol extract at 70°C. These results will be useful for development of health functional foods for anti-diabetes using 70% ethanol extract from unripe fruit of bitter melon ? 2015, Korean Society of Food Science and Nutrition. All rights reserved.