Silibinin protects GLUTag cells from PA-induced injury via suppressing endoplasmic reticulum stress

Silibinin is a natural flavonoid with anti-diabetic activity. Glucagon-like peptide-1 (GLP-1), an intestinal hormone mainly secreted from L cells, which regulates insulin production and sensitivity, appears to be a potential therapeutic strategy for T2DM. The current study aims to determine the protective effect of silibinin against palmitic acid (PA)-induced damage in GLUTag cells. The results revealed that PA triggered endoplasmic reticulum (ER) stress and apoptosis in GLUTag cells, while silibinin attenuated PA-induced lipotoxicity. Based on the estrogen-like effects of silibinin and the role of estrogen receptors in regulating glycolipid metabolism, the involvement of estrogen receptors in the protective effects of silibinin in GLUTag cells was further investigated. The results showed that estrogen receptor alpha- and beta-specific inhibitors reversed the inhibitory impact of silibinin on ER stress. Our study demonstrated that silibinin protects GLUTag cells from PA-induced injury by decreasing ER stress under the regulation of estrogen receptors alpha and beta.