Bioactive Compounds of Kimchi Inhibit Apoptosis by Attenuating Endoplasmic Reticulum Stress in the Brain of Amyloid β-Injected Mice

This study investigated the inhibitory effects of kimchi bioactive compounds against endoplasmic reticulum (ER) stress-induced apoptosis in amyloid beta (A beta)-injected mice. Mice received a single intracerebroventricular injection of A beta(25-35), except for the normal group. Mice were subjected to oral administration of 10 mg of capsaicin, 50 mg of 3-(4'-hydroxyl-3',5'-dimethoxyphenyl)propionic acid (HDMPPA), 50 mg of quercetin, 50 mg of ascorbic acid, or 200 mg of kimchi methanol extract (KME) per kilogram of body weight for 2 weeks (n = 7 per group). In the in vitro blood-brain barrier (BBB) permeability test, all bioactive compounds penetrated the BBB except ascorbic acid. The protein expression level of APP, BACE, and p-Tau elevated by A beta injection was decreased by kimchi bioactive compounds (P < 0.05). Quercetin, HDMPPA, and KME decreased oxidative stress, as indicated by ROS and TBARS levels (P < 0.05). The protein expression level of ER stress markers GRP78, p-PERK, p-eIF2 alpha, XBP1, and CHOP and the proapoptotic molecules Bax, p-JNK, and cleaved caspases-3 and -9 decreased (P < 0.05). In contrast, the protem expression level of antiapoptotic molecules Bcl2 and cIAP increased (P < 0.05). These results were supported by histological analysis.