Fig. 7: Indole-3-propionic acid (IPA) supplementation alleviates doxorubicin (DOX)-induced cardiac dysfunction, atrophy, and fibrosis in C57BL/6 mice.

a Schematic representation of treatment with doxorubicin (DOX) and low IPA (20 mg/kg) or high IPA (40 mg/kg) (n = 6 per group). b Anatomic M-mode echocardiography and corresponding electrocardiographic images of hearts from the indicated groups (n = 6). Changes of echocardiographic c left ventricular ejection fraction (LVEF) and d left ventricular fraction shortening (LVFS) in the indicated groups (n = 6). e, f Changes of serum lactate dehydrogenase (LDH) and creatine kinase-MB (CK-MB) levels in the four groups (n = 6). g Upper panel: representative H&E staining images of the heart tissue section from mice in the indicated groups. Bar = 100 μm. Bottom panel: wheat germ agglutinin (WGA) staining of myocardial tissue sections to evaluate cardiac atrophy. Bar = 50 μm. Right panel: quantitation of myocardial cell size of DIC mice in the indicated groups (n = 6). h Representative ×200 images of myocardial tissue sections stained with Masson’s trichrome (from top to bottom, the images are a panoramic view of the heart, a transverse section, and a longitudinal section). Right panel: quantification of the fractional area of cardiac fibrosis based on 6 randomly selected fields of stained myocardial tissue sections (n = 6). i–l Western blot analysis and quantification of extracellular matrix-related proteins, smooth muscle actin (SMA), collagen III, and collagen III in DOX-treated mice with IPA (n = 3). Data presented as mean ± SD. For statistical analysis, two-way ANOVA with Tukey’s test for multiple comparisons was used. *P < 0.05, **P < 0.01, ***P < 0.001.