Efficiency of the Enzymatic Conversion of Flavone Glycosides Isolated from Carrot Leaves and Anti-Inflammatory Effects of Enzyme-Treated Carrot Leaves

In traditional oriental medicine, carrots (Daucus carota L.) are considered effective medicinal herbs; however, the use of D. carota leaves (DCL) as therapeutic agents has not been explored in depth. Therefore, we aimed to demonstrate the value of DCL, generally treated as waste while developing plants for wide industrial availability. Six flavone glycosides were isolated and identified from DCL, and their constituents were identified and quantitated using an NMR and HPLC/UV method, which was optimized and validated. The structure of chrysoeriol-7-rutinoside from DCL was elucidated for the first time. The method exhibited adequate relative standard deviation (<1.89%) and recovery (94.89-105.97%). The deglycosylation of DCL flavone glycosides by Viscozyme L and Pectinex was assessed. Upon converting the reaction contents to percentages, the luteolin, apigenin, and chrysoeriol groups showed values of 85.8, 33.1, and 88.7%, respectively. The enzyme-treated DCL had a higher inhibitory effect on TNF-a and IL-2 expression than that of the carrot roots or carrot leaves without enzyme treatments. These results highlight the importance of carrot leaves and could be used as baseline standardization data for commercial development.

Automated summary

This study explored the medicinal value of carrot leaves and isolated six flavone glycosides from them. A method using NMR and HPLC/UV was developed for their quantitation. Enzymatic deglycosylation of the flavone glycosides was assessed, and the enzyme-treated carrot leaves showed higher inhibitory effects on TNF-a and IL-2 expression. These findings highlight the importance of carrot leaves and provide baseline data for commercial development.