Optimization of aqueous extraction of antioxidants from Chrysanthemum (C. morifolium Ramat and C. indicum L.) flowers and evaluation of their protection from glycoxidation damage on human αA-crystallin

Chrysanthemum tea is commonly consumed by Chinese consumers mainly due to the Chrysanthemum flower being a potential source of antioxidants. The current study investigates the effects of extraction time and temperature on Chrysanthemum flower aqueous extract (CFAE) antioxidant capacity, including Trolox equivalent antioxidant capacity (TEAC), ferrous iron-chelating activity, and superoxide radical scavenging capacity (SRSC) using a two-factor, three-level factorial design of the response surface method (RSM). The TEAC and SRSC of CFAE are higher at higher temperatures and longer times up to a certain point, and the highest TEAC and SRSC are achieved at a 100 °C extraction temperature for 45 min. The fructose induced-αA-crystallin (Cry) glycation model system was used to evaluate the effects of the CFAE on anti-glycoxidation activities. The antioxidant ingredients obtained from CFAE significantly impede the production of advanced glycation end products from protein glycoxidation products (dityrosine, kynurenine, and N'-methylkynurenine) in the glycation process of αA-Cry and exhibit strong anti-glycating activity. The glycation inhibitory effects of CFAE are concentration-dependent. C. indicum L. exhibits greater potential for preventing cataracts compared to C. morifolium Ramat CFAE's antioxidant and anti-glycation properties suggest its potential application as a natural ingredient in the development of agents to combat glycation.