Abstract:

Objective To investigate the effect of loganin on intestinal mucosal barrier，endoplasmic retic⁃ ulum stress（ERS）pathway and epithelial cell apoptosis in rats with burn injuries. Method Healthy male SD rats aged 8 ~ 12 weeks were selected and randomly divided into control group，burn group and intervention group. The control group was given normal saline（50 mg/kg）by gavage for 7 consecutive days before sham burn treatment，while the burn group was given normal saline（50 mg/kg）for 7 consecutive days before burned. The intervention group was treated with loganin（50 mg/kg）by gastric gavage for 7 consecutive days before injury. Rats were euthanized at 24 hours after burn，and intestinal tissue samples were surgically excised. The pathological changes of small intestinal tissue were observed and scored by HE staining ，and the ultrastructure of small intestinal epithelial cells was observed by transmission electron microscope. Flow cytometry was used to detect the proliferation and apoptosis of small intestinal mucosal cells，and Western blot was used to detect the expression changes of ERS⁃related proteins and apoptosis⁃related proteins in small intestinal tissues. Results There were statistically significant differences in the scores of lesion，inflammation，lesion extent，and crypt destruction among the three groups. The scores in the intervention group were lower than those in the burn group and higher than those in the control group（P < 0.05）. The apoptosis of small intestinal epithelial cells in the burn group was more serious than that in the intervention group，and the apoptosis rate was significantly higher than that in the intervention group（P < 0.05）. The protein expressions of Caspase⁃3，Bax，PERK，GRP 78 and CHOP in the intervention group were significantly higher than those in the control group and lower than those in the injury group，while Bcl⁃2 was higher than that in the injurygroup and lower than that in the control group（P < 0.05）. Conclusion Loganin could reduce the pathological damage of intestinal epithelium in rats with burn injuries and protect the structure of intestinal mucosa，and its mechanism may be related to inhibiting the ERS pathway of intestinal epithelial cells and reducing apoptosis.

Key words:

loganin, endoplasmic reticulum stress, epithelial cells, apoptosis, intestinal mucosa, burns