| Objective:To study Xinwei Granule’s influence on PI3K/Akt signaling pathway and regulation of downstream P-gp expression on the regulation platform of PI3K/Akt for P-gp,reveal its preventive effects and mechanism for precancerous lesions of gastric cancer(PLGC),and provide a theoretical basis for traditional Chinese medicine’s participation in the comprehensive prevention and treatment of PLGC and reversal of multidrug resistance of gastric cancer.Methods:The study numbered 210 healthy male Wistar rats by weight,and divided them randomly via random number table method into 7 groups,respectively:normal control group(N,n=30),model control group(M,n=30),Weifuchun control group(W,n=30),Vitacoenzyme control group(V,n=30),Xinwei Granule high-dose group(HX,n=30),Xinwei Granule middle-dose group(MX,n=30),Xinwei Granule low-dose group(LX,n=30).The study adopted free drinking of N-Methyl-N-Nitro-N-Nitrosoguanidine(MNNG),Leinitiding standard feeding and intragastric administration of high salt hot water,and meanwhile established a model by means of compound modeling method in collaboration with irregular diet.Each treated group received medical intervention during rat modeling.Groups HX,MX,LX:received 8.60g/kg,4.30g/kg,2.15g/kg of lyophilized powder of Xinwei Granule via intragastric administration respectively,once a day;Group V:received 0.32g/Kg Vitacoenzyme via intragastric administration,once a day;Group W:received Weifuchun 0.39g/Kg via intragastric administration,once a day;Group N,M:received distilled water of the same volume via intragastric administration,once a day.At the end of 16 weeks,4 rats from Group M were randomly chosen for gastric mucosa pathological histology examination and modeling and drug intervention were stopped immediately after confirming the successful modeling.All the rats were killed immediately after the successful model preparation.Their abdomens were cut open for stomachs,and the gastric mucosa was examined with naked eye and observed with a light microscope from the perspective of pathologic histology;meanwhile,immunehistochemical method,Real Time PCR and Western Blot methods were applied in detecting the expressions of P-Akt,Bax,Bcl-2,P-gp genes and proteins in gastric mucosa tissues.Results:(1)Rats’ general conditions:the macroscopic characteristics(fur luster,reaction sensitivity,excrement)and weight increase of Group M were all significantly worse than those of Group N.Compared with Group M,the macroscopic characteristics and weight increase of the rats in all the treated groups showed a significant improvement and the difference is of statistical significance(P<0.05,P<0.01);among the treated groups,Group MX showed the most significant improvement(P<0.05,P<0.01).(2)Gastric mucosa’s pathologic histology showed that:compared with that of Group N,Group M’s PLGC occurrence rate was significantly higher(P<0.01);compared with that of Group M,PLGC occurrence rates of all treated groups were all significantly lower and the difference was of statistical significance(P<0.01).A comparison among the treated groups showed that PLGC occurrence rates had no significant difference(P>0.05).(3)Results of immunohistochemical method showed that:compared with those of Group N,the expression levels of P-Akt,Bcl-2,P-gp proteins of Group M increased significantly and the expression level of Bax protein dropped significantly;the difference was of statistical significance(P<0.05).Compared with those of Group M,the expression levels of P-Akt,Bcl-2,P-gp protein of all the treated groups dropped significantly,notably Groups MX and HX;the two groups had no significant difference(P>0.05).Compared with those of Group M,the expression levels of Bax protein of all treated groups increased significantly,notably Groups MX and HX;the two groups had no significant difference(P>0.05).(4)Results of RT-PCR method showed that:compared with those of Group N,the transcription levels of P-Akt,Bcl-2,P-gpmRNA improved significantly and the transcription level of BaxmRNA dropped significantly;the difference was of statistical significance(P<0.05).Compared with those of Group M,the transcription levels of P-Akt,Bcl-2,P-gpmRNA of all the treated groups dropped significantly and the transcription levels of BaxmRNA increased significantly;the difference was of statistical significance(P<0.05).Among the treated groups,the transcription levels of P-Akt and Bcl-2mRNA of Group MX dropped most significantly;the transcription levels of P-gpmRNA in Groups MX and HX dropped most significantly,but there was no significant difference between the two groups;the transcription level of BaxmRNA in Group MX increased most significantly and the difference was of statistical significance(P<0.05).(5)Results of Western Blot methods showed that:compared with those of Group N,the expression levels of P-Akt,Bcl-25 P-gp protein in Group M increased significantly and the expression level of Bax protein dropped significantly;the difference was of statistical significance(P<0.05).Compared with those of Group M,the expression levels of P-Akt,Bcl-2,P-gp proteins of all treated groups dropped significantly,notably Group MX;the difference was of statistical significance(P<0.05).Compared with that of M,the Bax proteins of all treated groups increased significantly,notably Group MX;the difference was of statistical significance(P<0.05).Conclusion:(1)Xinwei Granule can effectively improve the general conditions and macroscopic characteristics of PLGC rat models,partly reverse the pathological state of rat’s gastric mucosa and lower PLGC occurrence rate.(2)Xinwei Granule can promote gastric epithelial apoptosis and cell proliferation suppression by suppressing the expressions of P-Akt and Bcl-2 genes and proteins,and promoting expressions of Bax genes and proteins in PLGC rat model’s gastric tissue.(3)Xinwei Granule can suppress the expressions of P-gp gene and protein in PLGC rat model’s gastric tissue.(4)Xinwei Granule can further mediate P-gp’s low expression by suppressing the activation of PI3/Akt signaling pathway. |
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