Protective effect of Shenfu Injection on rats with chronic heart failure based on HMGB1/TLR4/NF-κB signaling pathway

Abstract

The study aimed to explore the mechanism and targets of Shenfu Injection in the regulation of inflammatory injury in chronic heart failure rats based on the high mobility group box-1/Toll like receptor 4/nuclear factor kappa-B(HMGB1/TLR4/NF-κB) signaling pathway. The rat model of chronic heart failure was established using isoproterenol. The modeled rats were divided into three groups by random number table: the model group, Shenfu group and glycopyrrolate group, and the normal group was also set. The rats were administrated for 15 consecutive days, and on the following day after the last administration, they were sacrificed for sample collection. The cardiac mass index and left ventricular mass index of the rats in each group were measured, and the echocardiogram was used to analyze the cardiac function indices, and ELISA to test the inflammatory indices in rat serum. The pathological morphology and fibrosis status of rat heart tissues were observed by HE staining and Masson staining, respectively. The content of HMGB1 was determined by immunofluorescence staining. The protein and mRNA expression of HMGB1/TLR4/TLR4 signaling pathway was detected by Western blot and RT-qPCR, respectively. The results showed that the chronic heart failure rat model was successfully prepared. The rats in the model group had reduced cardiac function, increased levels of HMGB1 and inflammatory factors(P<0.05), and elevated protein and mRNA expression of HMGB1, TLR4, MyD88, and NF-κB P65 in myocardial tissue(P<0.05), with fibrous connective tissue hyperplasia, inflammatory cell infiltration and severe fibrosis. Shenfu Injection improved cardiac function, decreased the levels of HMGB1 and inflammatory factors(P<0.05) and the protein and mRNA expression of HMGB1, TLR4, MyD88, and NF-κB P65 in myocardial tissue(P<0.05), ameliorated interstitial fibrous connective tissue hyperplasia and inflammatory cell infiltration, and reduced fibrosis. In conclusion, Shenfu Injection can reduce inflammatory damage and improve cardiac function in chronic heart failure rats by regulating the HMGB1/TLR4/NF-κB signaling pathway.