Acetylated pelargonidin-3-O-glucoside exhibits promising thermostability, lipophilicity, and protectivity against oxidative damage by activating the Nrf2/ARE pathway

Abstract

Anthocyanins are natural products that display diverse bioactivities but are limited in their applications by low stability and bioavailability. Acylated anthocyanins are found to possess higher stability, while their bioactivities are still obscure. In this study, acetylation of pelargonidin-3-O-glucoside (Pg3G) was catalyzed by Candida antarctica lipase B (CALB) for the first time, with a conversion rate up to 88.77% over 48 h. The acetylated product was identified as pelargonidin-3-O-(6′′-acetyl)-glucoside and its properties were detected. Notably, acetylated Pg3G (Ace Pg3G) possessed better thermostability and lipophilicity than Pg3G, indicating a longer retention time at physiological pH and facilitating penetration into the lipophilic medium as well as the cell membrane. Most importantly, Ace Pg3G exerted better alleviation effects against H₂O₂-induced oxidative hepatic damage than parent Pg3G via activating the Nrf2/ARE signaling pathway and upregulating the expressions of the downstream phase II detoxification enzymes GCLC and HO-1, thereby reversing redox imbalance and enhancing cell survival. Overall, our research unveiled the better health benefits of Ace Pg3G and also provided new insights about the applications of acetylated anthocyanins in food, cosmetic, and pharmaceutical products.