Extraction and enrichment of anthocyanins from Cerasus humilis and the inhibition on low density lipoprotein oxidation by cyanidin-3-O-glucoside

Abstract

The extraction technologies and functional activities of anthocyanins have received increasing attention recently. Cerasus humilis (Bge.) Sok. anthocyanins (CHA) were extracted using natural deep eutectic solvents (NADES) combined with a probe-type ultrasound-assisted technique. Choline chloride-citric acid deep eutectic solvent was identified as the most suitable NADES for extracting CHA. Under optimal extraction conditions, the yield of CHA reached 66.1 ± 0.2 mg/100 g dry weight (p < 0.05). To enhance the purity of CHA, XDA-7 resin was used for enrichment due to its favorable adsorption/desorption capacity and recovery efficiency (92.0 %, 75.4 %, and 69.4 %, respectively). The adsorption behavior of XDA-7 resin on CHA was well described by the Langmuir model, indicating a potential monolayer adsorption mechanism. Cyanidin-3-O-glucoside (C3G) was identified as the most abundant component in enriched CHA by LC/MS². The inhibition of C3G on low-density lipoprotein (LDL) oxidation was further investigated. The lag times of conjugated diene formation during LDL lipid peroxidation were evaluated using the four-parameter logistic regression model, which showed an extension of 9.09 %, 28.9 %, and 52.9 % in a concentration-dependent manner (R² ≥ 0.985). Moreover, C3G also reduced the oxidative modification of apolipoprotein B100 (apoB100), the only protein component in LDL. Protein-ligand interaction studies between C3G and apoB100 indicated the formation of a ground-state complex primarily maintained by electrostatic interactions, suggesting that C3G may be transported by LDL to atherosclerotic plaques, potentially serving anti-atherogenic purposes. In conclusion, this study presents an efficient method for CHA extraction and highlights the potential of CHA in anti-atherogenic functions.