Anthocyanins from Chinese Bayberry Extract Activate Transcription Factor Nrf2 in β Cells and Negatively Regulate Oxidative Stress-Induced Autophagy

• Published in: Journal of agricultural and food chemistry Vol. 61; no. 37; pp. 8765 - 8772
• Main Authors: Zhang, Bo, Buya, Miranbieke, Qin, Wenjie, Sun, Chongde, Cai, Haolei, Xie, Qiuping, Xu, Bing, Wu, Yulian
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 18.09.2013
• Subjects: Animals; anthocyanins; Anthocyanins - pharmacology; apoptosis; Apoptosis - drug effects; autophagy; Autophagy - drug effects; Biological and medical sciences; Cell Line; Cell Survival - drug effects; cell viability; Diabetes Mellitus, Type 1 - genetics; Diabetes Mellitus, Type 1 - metabolism; Diabetes Mellitus, Type 1 - physiopathology; Diabetes Mellitus, Type 1 - therapy; Drugs, Chinese Herbal - pharmacology; Food industries; Fundamental and applied biological sciences. Psychology; heme oxygenase (decyclizing); Humans; hydrogen peroxide; Insulin-Secreting Cells - cytology; Insulin-Secreting Cells - drug effects; Insulin-Secreting Cells - metabolism; Insulin-Secreting Cells - transplantation; Mice; Mice, Inbred ICR; Morella rubra; Myrica - chemistry; NF-E2-Related Factor 2 - genetics; NF-E2-Related Factor 2 - metabolism; Oxidative Stress - drug effects; Rats; transcription factors; Up-Regulation - drug effects; islet transplantation; autophagy; heme oxygenase-1; anthocyanins; Nrf2; oxidative stress; Anthocyanin; Oxidative stress; Langerhans islet; Extract; Transplantation; Autophagy; Flavonoid; Polyphenol; Regulation(control); Heme; Pigments; β Cell; Transcription factor; Endocrine pancreas
• ISSN: 0021-8561; 1520-5118
• DOI: 10.1021/jf4012399

Islet replacement is a promising cure for insulin-dependent diabetes but is limited by a massive early cell death following transplantation. Overburden oxidative stress is one of the major factors causing cell damage. We have shown previously that anthocyanins in Chinese bayberry extract protected β cells (INS-1) from hydrogen peroxide (H2O2)-induced apoptosis and decreased grafts’ apoptosis after transplantation partially through heme oxygenase-1 (HO-1) up-regulation. In the present study, we observed that H2O2 stimulation induced autophagy in β cells. Inhibition of autophagy increased cell viability and decreased cell death. Anthocyanin pretreatment attenuated oxidative stress-mediated autophagic cell death. Anthocyanins activated antioxidant transcription factor Nrf2 in INS-1 cells, and Nrf2/HO-1 negatively regulated autophagy process. Furthermore, we here demonstrate that autophagy also took place in β cell grafts during the early post-transplantation phase. β Cells pretreated with anthocyanins displayed decreased extent of autophagy after transplantation. Taken together, these findings further supported the conclusion that anthocyanins could serve as a protective agent of β cells and suggested that autophagy might play a role in β cells during transplantation.