Rajappa Rashmi, Sireesh Dornadula, Salai Magesh B, Ramkumar Kunka M, Sarvajayakesavulu Suryanarayanan, Madhunapantula SubbaRao V
Department of Water & Health, Faculty of Life Sciences, JSS Academy of Higher Education and Research, Mysuru, India.
SRM Institute of Science and Technology, Chennai, India.
Front Pharmacol. 2019 Jan 28;9:1562. doi: 10.3389/fphar.2018.01562. eCollection 2018.
Chronic hyperglycemia and unusually high oxidative stress are the key contributors for diabetes in humans. Since nuclear factor E2-related factor 2 (Nrf2) controls the expression of antioxidant- and detoxification genes, it is hypothesized that targeted activation of Nrf2 using phytochemicals is likely to protect pancreatic β-cells, from oxidative damage, thereby mitigates the complications of diabetes. Naringenin is one such activator of Nrf2. However, it is currently not known whether the protective effect of naringenin against streptozotocin (STZ) induced damage is mediated by Nrf2 activation. Hence, the potential of naringenin to activate Nrf2 and protect pancreatic β-cells from STZ-induced damage in MIN6 cells is studied. In MIN6 cells, naringenin could activate Nrf2 and its target genes GST and NQO1, thereby inhibit cellular apoptosis. In animals, administration of 50 mg/kg body weight naringenin, for 45 days, significantly decreased STZ-induced blood glucose levels, normalized the lipid profile, and augmented the levels of antioxidants in pancreatic tissues. Immunohistochemical analysis measuring the number of insulin-positive cells in pancreas showed restoration of insulin expression similar to control animals. Furthermore, naringenin promoted glycolysis while inhibiting gluconeogenesis. In conclusion, naringenin could be a good anti-diabetic agent, which works by promoting Nrf2 levels and by decreasing cellular oxidative stress.
慢性高血糖和异常高的氧化应激是人类患糖尿病的关键因素。由于核因子E2相关因子2(Nrf2)控制抗氧化和解毒基因的表达,因此推测使用植物化学物质靶向激活Nrf2可能保护胰腺β细胞免受氧化损伤,从而减轻糖尿病的并发症。柚皮素就是这样一种Nrf2激活剂。然而,目前尚不清楚柚皮素对链脲佐菌素(STZ)诱导损伤的保护作用是否由Nrf2激活介导。因此,研究了柚皮素在MIN6细胞中激活Nrf2并保护胰腺β细胞免受STZ诱导损伤的潜力。在MIN6细胞中,柚皮素可以激活Nrf2及其靶基因GST和NQO1,从而抑制细胞凋亡。在动物中,给予50mg/kg体重的柚皮素,持续45天,可显著降低STZ诱导的血糖水平,使血脂谱正常化,并提高胰腺组织中抗氧化剂的水平。免疫组织化学分析测量胰腺中胰岛素阳性细胞的数量,结果显示胰岛素表达恢复到与对照动物相似的水平。此外,柚皮素促进糖酵解,同时抑制糖异生。总之,柚皮素可能是一种良好的抗糖尿病药物,其作用机制是提高Nrf2水平并降低细胞氧化应激。