Phenolic profiles, antioxidant activity and inhibition of digestive enzymes of water caltrop pericarps.

BACKGROUND Water caltrop (Trapa natans L.) is widely cultivated as a popular vegetable or fruit in Asian countries. In China, water caltrop pericarp is also used as a functional food to treat metabolic syndrome. However, the profiling of bioactive substances or their pharmacological activities of different water caltrop varieties remain to be investigated. In this work, three varieties of water caltrop pericarps collected from thirteen origins in China were analyzed for their phenolic substances. To investigate the pharmacological activities, samples were tested for their free radical scavenging capacity and inhibitory potency against α-glucosidase and pancreatic lipase. RESULTS In total, 46 phenolic compounds were identified in the ethanol extract of water caltrop pericarp using a LC-QTOF-MS/MS method, most of which were hydrolyzable tannins. Two cultivated varieties samples exhibited relatively higher phenolic content, stronger antioxidant and inhibitory activities against α-glucosidase and pancreatic lipase in comparison with those from the wild variety. Correlation analysis between phenolic contents and biological activities suggested that phenolic compounds exhibited potential free radical scavenging capacity, α-glucosidase and pancreatic lipase inhibitory activities. CONCLUSIONS It is concluded that phenolic compounds of water caltrop pericarp are promising sources of natural antioxidants, α-glucosidase and pancreatic lipase inhibitors. This article is protected by copyright. All rights reserved.