Combined network pharmacology and metabolomics reveal that Rubia cordifolia L. ameliorates exhaustive exercise-induced myocardial injury in rats via the BCAA degradation pathway

Rubia cordifolia L. (RCL) is a widely used medicinal with a long history. It exhibits anti-inflammatory and antioxidant properties and prevents apoptosis. While there is growing evidence that exhausted exercise (EE) might cause cardiac damage, RCL has been shown to provide cardioprotective effects. The effects and mechanisms of RCL on exercise-induced myocardial injury remain unclear. In this study, we tested the RCL extract using a rat model of exhausted swimming. We evaluated the therapeutic effect of RCL on exercise-induced myocardial damage using PCR, ELISA, hematoxylin-eosin (H&E) staining, DHE staining, and other methods. UPLC-Q-TOF-MS was employed to identify the components of the RCL extract and its blood-entry components, and network pharmacology was constructed. LC-MS was utilized to investigate left ventricular metabolomics. These two approaches were combined to predict the possible metabolic pathways regulated by RCL. Finally, the targets of the metabolic pathway were verified using molecular docking and western blot analysis. The findings suggest that rubioncolin B, 4-hydroxy-2-carbexyanthraquinone, and 9-Oxo-9H-xanthene-4-carboxylic acid may be the primary active compounds of RCL. RCL promotes the degradation pathway of branched-chain amino acids (BCAA), including valine, leucine, and isoleucine, regulates the proteins BCAT2 and BCKDK, reduces pathological injuries, inflammation, oxidative stress, and collagen deposition, and mitigates the effects of exhaustion-induced myocardial injuries by influencing the key target AKR1C1 and the metabolite L-Valine. This study provides a foundation for the development of RCL as a sports supplement to alleviate EE-induced myocardial injury.