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.
ABSTRACT
Objective:To establish a method for the determination of solvent residues in faeces bombycis extract by GC .Meth-ods: A GC-headspace injection method was adopted to detect the residual organic solvents in the extract of faeces bombycis .A DB-5MS (30 m ×0.25 mm ×0.25 μm) quartz capillary column was used as the chromatographic column;nitrogen was used as the carrier gas at a flow rate of 0.6 ml· min-1;the injector temperature was 200℃;the detector was a flame ionization detector( FID) with the temperature of 250℃;the temperature program included two phases:the initial temperature was set at 40℃for 10 min, and then risen to 200℃at a rate of 5℃· min-1 and maintained for 5 min;the equilibrium temperature of headspace was 95℃;the equilibrium time was 30 min;the capillary temperature was 110℃;the injection ring temperature was 125℃.Results:The linear range of acetone , 2, 3-dimethylpentane, 3-methylhexane, heptane, 2,2-dimethylhexane, p-xylene, m-xylene, O-xylene and 2,4,6-collidine was 101-3 034μg· ml-1 , 100-2 995 μg· ml-1 , 107-3 197 μg· ml-1 , 101-3 019 μg· ml-1 , 99-2 962 μg· ml-1 , 45-1 358 μg· ml-1 , 44-1 325μg· ml-1, 47-1 411 μg· ml-1 and 104-3 130 μg· ml-1, respectively, and the average r was all above 0.992.The recovery of the method met the requirement , and the blank solvent showed no interference .Eight samples were all accordance with the requirements after the examination .Conclusion:The headspace injection method for the determination of residual organic solvents in the extract of faeces bombycis is simple and reliable .