Effect of Faeces Bombycis Extract on Cajal Interstitial Cells in Diabetic Gastroparesis Rats Based on PI3K/Akt/mTOR Signaling Pathway / 中国实验方剂学杂志

ABSTRACT

ObjectiveTo explore the therapeutic mechanism of Faeces Bombycis on diabetic gastroparesis （DGP） rats based on phosphatidylinositol 3-kinase/protein kinase B/mammalian rapamycin target protein （PI3K/Akt/mTOR） signaling pathway. MethodDGP rat model was prepared by random selection of 15 out of 105 rats as blank group. The rats successfully constructed were randomly divided into model group， high-，medium- and low- dose groups （3.2， 1.6， 0.8 g·kg-1） and moxapride group （1.5 mg·kg-1）， with 12 rats in each group， and were given gavage for 4 weeks. The gastric emptying rate and random blood glucose were measured. The morphological changes of gastric antrum were observed by hematoxylin-eosin （HE） staining， and the expression of the c-Kit gene was analyzed by immunohistochemistry. The apoptosis of Cajal interstitial cells was observed by in situ end labeling （TUNEL） staining， and the protein expressions of PI3K， phosphorylation（p）-PI3K， Akt， p-Akt， mTOR， and p-mTOR were detected by Western blot. ResultCompared with the blank group， the gastric emptying rate of the model group decreased significantly （P<0.01）， and the glandular structure of the gastric antrum was destroyed. The expression of c-Kit decreased （P<0.01）， and the apoptosis of Cajal interstitial cells （ICC） increased. Compared with the model group， the gastric emptying rate in the high， middle， and low-dose groups of Faeces Bombycis extract and mosapride group increased significantly （P<0.01）. The glandular structure of the gastric antrum became closer， and the apoptosis of ICC decreased. The expression of c-Kit in the high dose group of Faeces Bombycis extract increased significantly. After Western blot testing， compared with the blank group， the protein expression of p-Akt/Akt， p-PI3K/PI3K， and p-mTOR/mTOR in the model group increased. Compared with the model group， the protein expression of p-Akt/Akt in the high dose group of Faeces Bombycis extract decreased （P<0.01）， and the protein expression of p-PI3K/PI3K decreased in the middle and low dose groups of Faeces Bombycis extract and mosapride group decreased （P<0.05， P<0.01）. The protein expression of p-mTOR/mTOR decreased in the low dose group of Faeces Bombycis extract （P<0.05）. In terms of random blood glucose， compared with the blank group， the random blood glucose in the model group increased significantly （P<0.01）， and compared with the model group， the random blood glucose in the high and middle dose groups of Faeces Bombycis extract decreased significantly （P<0.05）. Compared with mosapride group， the protein expression of p-Akt/Akt decreased in the high dose group of Faeces Bombycis extract （P<0.05）， and the protein expression of p-PI3K/PI3K increased in the high， middle， and low dose groups of Faeces Bombycis extract （P<0.05， P<0.01）. ConclusionFaeces Bombycis extract can increase gastric emptying rate， reduce ICC apoptosis， and lower random blood glucose in DGP rats. The high dose group of Faeces Bombycis extract has a significant effect on inhibiting ICC apoptosis， and its mechanism may be related to the regulation of the PI3K/Akt/mTOR signaling pathway.