Shenxiang Suhe pill improves cardiac function through modulating gut microbiota and serum metabolites in rats after acute myocardial infarction

Abstract

Context: Shenxiang Suhe pill (SXSH), a traditional Chinese medicine, is clinically effective against coronary heart disease, but the mechanism of cardiac-protective function is unclear.

Objective: We investigated the cardiac-protective mechanism of SXSH via modulating gut microbiota and metabolite profiles.

Materials and methods: Sprague-Dawley (SD) male rats were randomly divided into 6 groups (n = 8): Sham, Model, SXSH (Low, 0.063 g/kg; Medium, 0.126 g/kg; High, 0.252 g/kg), and Ato (atorvastatin, 20 mg/kg). Besides the Sham group, rats were modelled with acute myocardial infarction (AMI) by ligating the anterior descending branch of the left coronary artery (LAD). After 3, 7, 14 days' administration, ultrasound, H&E staining, serum enzymic assay, 16S rRNA sequencing were conducted to investigate the SXSH efficacy. Afterwards, five groups of rats: Sham, Model, Model-ABX (AMI with antibiotics-feeding), SXSH (0.126 g/kg), SXSH-ABX were administrated for 14 days to evaluate the gut microbiota-dependent SXSH efficacy, and serum untargeted metabolomics test was performed.

Results: 0.126 g/kg of SXSH intervention for 14 days increased ejection fraction (EF, 78.22%), fractional shortening (FS, 109.07%), and aortic valve flow velocities (AV, 21.62%), reduced lesion area, and decreased serum LDH (8.49%) and CK-MB (10.79%). Meanwhile, SXSH upregulated the abundance of Muribaculaceae (199.71%), Allobaculum (1744.09%), and downregulated Lactobacillus (65.51%). The cardiac-protective effect of SXSH was disrupted by antibiotics administration. SXSH altered serum metabolites levels, such as downregulation of 2-n-tetrahydrothiophenecarboxylic acid (THTC, 1.73%), and lysophosphatidylcholine (lysoPC, 4.61%).

Discussion and conclusion: The cardiac-protective effect and suggested mechanism of SXSH could provide a theoretical basis for expanding its application in clinic.

Keywords: 2-n-tetrahydrothiophenecarboxylic acid (THTC); Allobaculum; Lactobacillus; Traditional Chinese medicine (TCM); lysophosphatidylcholine (lysoPC); muribaculaceae; serum metabolic biomarker.

Figure 1.

SXSH protects cardiac function after AMI. (A) The schematic diagram for SXSH administration in rats after AMI. (B) Representative parasternal long-axis views and M-mode images. (C) Representative color Doppler imaging of the cardiac outflow tract and blood flow velocity. (D-F) The quantization charts corresponding to EF, FS, and AV. (G) Representative heart pictures of H&E staining (scale bar equals 100 µm). serum activities of (H) LDH, and (I) CK-MB. ^#p < 0.05, ^##p < 0.01 vs. Sham and *p < 0.05, **p < 0.01 vs. Model.

Figure 2.

SXSH modulates gut microbiota post AMI. (A) Alpha diversity of Shannon index in each group. (B) Beta diversity of Bray Curtis-based PCoA of medium dose SXSH groups for 3 days, 7 days, and 14 days administration. (C) Statistical analysis of representative OTUs among different groups after 14 days administration.

Figure 3.

Antibiotics induced dysbacteriosis interferes cardiac protective effect of SXSH. (A) The schematic diagram for SXSH and ABX administration in AMI rats. (B) Representative parasternal long-axis views and M-mode images, and color Doppler imaging of the cardiac outflow tract and blood flow velocity. (C-E) The quantization charts corresponding to EF, FS, and AV. (F) Representative heart pictures of H&E staining [scale bar equals 3000 µm (top), 650 µm and 75 µm (bottom)]. serum activities of (G) SOD, (H) MDA, (I) LDH, and (J) CK-MB. ^#p < 0.05, ^##p < 0.01, ^###p < 0.001 vs. Sham, **p < 0.01, ***p < 0.001 vs. Model, and ^{^^}p < 0.01, ^{^^^}p < 0.001 vs. SXSH.

Figure 4.

Circulating metabolomics for the quantification of metabolites among different groups. (A) The PCA score plots between Sham and Model in positive ion mode [R²Xp1 = 0.336, R²Xp2 = 0.224] and negative ion mode [R²Xp1 = 0.327, R²Xp2 = 0.267]. (B) The OPLS-DA score plots between Sham and Model in positive ion mode [R²X = 0.422, R²Y = 0.973, Q² = 0.859] and negative ion mode [R²X = 0.346, R²Y = 0.912, Q² = 0.695]. (C) Volcano plot showing the differentially accumulated and significantly changed metabolites in Model group compared to Sham. (D) The PCA score plots between Sham, Model, and SXSH in positive ion mode [R²Xp1 = 0.21, R²Xp2 = 0.149, R²Xp3 = 0.116, R²Xp4 = 0.112] and negative ion mode [R²Xp1 = 0.229, R²Xp2 = 0.182, R²Xp3 = 0.119]. (E) Pathway enrichment based on altered metabolites.

Figure 5.

Biomarker analysis and heatmap of identified marker metabolites. (A) Spearman correlation analysis among key efficacy indicators and marker metabolites. (B) Heatmap of selected marker metabolites among SXSH and SXSH-ABX group based on VIP > 1.