Department of Pharmacology and Toxicology, Faculty of Pharmaceutical Sciences and Drug Manufacturing, Misr University for Science and Technology (MUST), 6th of October City, Giza, Egypt.
Department of Biochemistry, Faculty of Pharmaceutical Sciences and Drug Manufacturing, Misr University for Science and Technology (MUST), 6th of October City, Giza, Egypt.
Life Sci. 2021 Jun 15;275:119370. doi: 10.1016/j.lfs.2021.119370. Epub 2021 Mar 17.
This study aimed to investigate the gastroprotective effect of chlorogenic acid (CGA) against Indomethacin (IND)-induced gastric ulcer (GU) in rats and its underlying mechanism, especially through autophagic and apoptotic pathways.
Seventy-five rats were divided into five groups; control, IND (50 mg/kg, p.o.), CGA (100 mg/kg, p.o., 14 days), IND pretreated with CGA (50 mg/kg or 100 mg/kg, p.o., 14 days). The stomach tissues were examined to calculate the ulcer index and analyze markers of autophagy (beclin-1, LC3-II/LC3-I and p62), lysosomal function (cathepsin-D) and apoptosis (Bcl-2, Bax and caspase-3), along with expression of Akt/mTOR pathway using western blot or ELISA techniques. In addition, viability of gastric mucosal cells was detected by flowcytometry. Structural changes were assessed histologically, while autophagic and apoptotic changes of gastric mucosa were observed by transmission electron microscopy.
CGA exhibited a dose-dependent gastroprotective effect by reversing IND-induced accumulation of autophagic vacuoles, significant reduction in beclin-1, LC3-II/LC3-I, and p62 levels, and down-regulation of p-Akt/p-mTOR expression. CGA100 also restored normal autolysosomal function by modulation of cathepsin-D levels. Furthermore, pretreatment with CGA100 was significantly associated with an increase in antiapoptotic protein Bcl-2 along with a decrease in proapoptotic Bax and caspase-3 proteins in such a way that impairs IND-induced apoptosis. This was confirmed by CGA-induced significant decrease in annexin V cells.
The natural compound CGA offers a novel gastroprotective intervention against IND-induced GU through restoration of normal autophagic flux, impairment of apoptosis in a crosstalk mechanism mediated by Akt/mTOR pathway reactivation, and alleviation of IND-induced lysosomal dysfunction.
本研究旨在探讨绿原酸（CGA）对吲哚美辛（IND）诱导的大鼠胃溃疡（GU）的胃保护作用及其潜在机制，特别是通过自噬和凋亡途径。
75 只大鼠分为 5 组；对照组、IND（50mg/kg，po）、CGA（100mg/kg，po，14 天）、IND 预处理 CGA（50mg/kg 或 100mg/kg，po，14 天）。检查胃组织计算溃疡指数，并分析自噬标志物（beclin-1、LC3-II/LC3-I 和 p62）、溶酶体功能（组织蛋白酶-D）和凋亡标志物（Bcl-2、Bax 和 caspase-3），以及使用 Western blot 或 ELISA 技术检测 Akt/mTOR 通路的表达。此外，通过流式细胞术检测胃黏膜细胞活力。组织学评估结构变化，透射电镜观察胃黏膜的自噬和凋亡变化。
CGA 通过逆转 IND 诱导的自噬小体积累、显著降低 beclin-1、LC3-II/LC3-I 和 p62 水平以及下调 p-Akt/p-mTOR 表达，表现出剂量依赖性胃保护作用。CGA100 还通过调节组织蛋白酶-D 水平恢复正常自溶酶体功能。此外，CGA100 的预处理与抗凋亡蛋白 Bcl-2 的增加以及促凋亡 Bax 和 caspase-3 蛋白的减少显著相关，以损害 IND 诱导的细胞凋亡。CGA 诱导的 annexin V 细胞显著减少证实了这一点。
天然化合物 CGA 通过恢复正常自噬流、通过 Akt/mTOR 通路再激活介导的细胞凋亡损伤以及减轻 IND 诱导的溶酶体功能障碍，为 IND 诱导的 GU 提供了一种新的胃保护干预措施。
