Simulated gastrointestinal digestion and colonic fermentation of blue honeysuckle: Phenolic profile and protectivity on ethyl carbamate-induced oxidative damage

Abstract

Blue honeysuckle (Lonicera caerulea L.) is well-known fruit that belongs to the berries family, and is widely cultivated in China, Russia, and Japan. This study aimed to evaluate the impact of in vitro gastrointestinal digestion followed by gut microbiota fermentation on the phenolic profile of blue honeysuckle as well as the protective effect of digested-blue honeysuckle against ethyl carbamate (EC)-induced oxidative damage. Results of phenolic profile showed that cyanidin-3-O-glucoside was identified as the predominant anthocyanin in blue honeysuckle and was significantly decreased after in vitro digestion. The generation of some metabolites (gallic acid, ferulic acid, and 3,4-dihydroxybenzoic acid) could be attributed to the degradation of chlorogenic acid and anthocyanins. Cellular studies indicated that digested-blue honeysuckle (0.5 and 1 mg/mL) exhibited significant protection against EC-induced cytotoxicity. Digested-blue honeysuckle at a concentration 1.0 mg/mL exhibited significant (p < 0.05) protective effect against EC-induced cytotoxicity in Caco-2 cells via inhibiting ROS and superoxide anion accumulation, attenuating GSH depletion, and inhibiting mitochondrial membrane potential collapse compared to EC-treated group. Blue honeysuckle could be a promising resource for ameliorating EC-induced cellular oxidative damage, which could be an ingredient for functional foods. However, further in vivo studies are recommended to prove the functionality of blue honeysuckle.