Citrus flavonoids particularly quercetin which is abundant in grapefruit, onion, green tea, berries etc. are known to have a protective effect on oxidative stress. Pancreatic β cells which synthesize and secrete insulin are prone to oxidative stress induced damage because of low cellular antioxidant enzymes. To delineate the effects of quercetin on pancreatic β cells we evaluated the protective effect of quercetin on TC6 insulinoma cells subjected to oxidative stress induced by tert-butyl-hydrogen-peroxide (TBHP). Quercetin was found to reduce TBHP induced apoptosis and trigger insulin secretion in response to glucose, in a dose-dependent manner. Quercetin treatment increased mitochondrial biogenesis, caused hypertrophy in pancreatic β cells and activated mTOR signaling with a transient change in mitochondrial membrane potential and AMP/ATP. Activation of mTOR signaling resulted in enhanced insulin secretion in TC6 cells.

已知柑橘类黄酮，尤其是柚子、洋葱、绿茶、浆果等中富含的槲皮素对氧化应激具有保护作用。由于细胞抗氧化酶含量低，合成和分泌胰岛素的胰腺β细胞容易受到氧化应激诱导的损伤。为了描述槲皮素对胰腺 β 细胞的影响，我们评估了槲皮素对叔丁基过氧化氢 (TBHP) 诱导的氧化应激的 TC6 胰岛素瘤细胞的保护作用。发现槲皮素以剂量依赖性方式减少 TBHP 诱导的细胞凋亡并触发胰岛素分泌以响应葡萄糖。槲皮素治疗增加了线粒体的生物合成，导致胰腺 β 细胞肥大并激活 mTOR 信号传导，线粒体膜电位和 AMP/ATP 发生短暂变化。