Effect of moxibustion at “Feishu” （BL13） and “Xinshu”（BL15） on myocardial fibrosis in chronic heart failure rats based on ferroptosis

ObjectiveTo observe the effect of moxibustion at “Feishu” （BL13） and “Xinshu” （BL15） on cardiac nuclear receptor co activator 4 （NCOA4）， divalent metal transporter 1 （DMT1） and type Ⅲ collagen cardiac collagen fibers （Collagen Ⅲ） in rats with chronic heart failure （CHF）， so as to explore its underlying mechanisms in improvement of CHF.MethodsMale SD rats were randomly divided into the normal （n=10）， model （n=5）， moxibustion （n=7）， rapamycin （n=4）， and moxibustion + rapamycin （n=5） groups. The CHF model was established by permanent ligation of the anterior descending branch of the left coronary artery. In the moxibustion and moxibustion + rapamycin group， mild moxibustion was applied to bilateral BL13 and BL15 for 15 min once daily for 4 weeks. In the rapamycin and moxibustion + rapamycin group， rapamycin solution （1 mg/kg） was intraperitoneally injected once a day for 4 weeks. Behavioral observations were conducted on rats in each group. The ejection fraction （EF） and left ventricular fractional shortening rate （FS） were examined by echocardiography. Masson staining and transmission electron microscopy were used to observe the structural morphology of the rats’ heart. Immunofluorescence colocalization was used to observe the colocalization of NCOA4 and autophagy microtubule-associated protein light chain 3B （LC3B）. Real-time fluorescent quantitative PCR was used to detect the mRNA expressions of NCOA4， DMT1， and Collagen Ⅲ in the myocardial tissues of rats in each group， and Western blot was used to detect the protein levels of DMT1 and Collagen Ⅲ.Results（1） After modeling， the mitochondrial cristae of cardiomyocytes were disrupted or even disappeared， the EF and FS values were decreased （PPPPPPPConclusionMoxibustion can reduce the expression of NCOA4 and DMT1， inhibit the combination of NCOA4 and LC3B， thereby antagonizing ferritin autophagy， improving iron metabolism disorders， inhibiting ferroptosis and down-regulating Collagen Ⅲ expression， ultimately slowing the process of CHF myocardial fibrosis.