<i>Portulaca oleracea L</i>. Extract Ameliorates Intestinal Inflammation by Regulating Endoplasmic Reticulum Stress and Autophagy
Ziwei Zhang, Dan Qiao, Yali Zhang, Qian Chen, Yu-Jung Chen, Yingjue Tang, Renye Que, Ying Chen, Lie Zheng, Yan-Cheng Dai, Zhipeng Tang
Abstract
SCOPE: To investigate the role of endoplasmic reticulum stress (ERS)-induced autophagy in inflammatory bowel disease (IBD) and the intervention mechanism of Portulaca oleracea L. (POL) extract, a medicinal herb with anti-inflammatory, antioxidant, immune-regulating, and antitumor properties, in vitro and in vivo. METHODS AND RESULTS: An IL-10-deficient mouse model is used for in vivo experiments; a thapsigargin (Tg)-stimulated ERS model of human colonic mucosal epithelial cells (HIECs) is used for in vitro experiments. The levels of ERS-autophagy-related proteins are examined by immunofluorescence and Western blot. Cellular ultrastructure is assessed with transmission electron microscopy. POL extract promotes a healing effect on colitis by regulating ERS-autophagy through the protein kinase R-like endoplasmic reticulum kinase (PERK)-eukaryotic initiation factor 2α (eIF2α)/Beclin1-microtubule-associated protein light chain 3II (LC3II) pathway. CONCLUSION: Overall, the results of this study further confirm the anti-inflammatory mechanism and protective effect of POL extract and provide a new research avenue for the clinical treatment of IBD.