Therapeutic Targeting of Viral Myocarditis with Natural Products and Herbal Medicines: From Immune-Inflammatory Mechanisms to Clinical Translation

Viral myocarditis (VMC) is a heterogeneous inflammatory myocardial disease initiated by viral infection and sustained by dysregulated innate and adaptive immunity. Its progression can be viewed as a stage-dependent continuum: virus-triggered macrophage and T-cell dysregulation initiates immune-inflammatory amplification; oxidative stress and autophagy-lysosomal dysfunction further intensify myocardial injury; and these processes ultimately converge on cardiomyocyte death and fibrotic remodeling. We conducted a structured narrative review of relevant clinical and preclinical studies identified through major English- and Chinese-language databases and reference-list screening. Distinct from previous reviews that mainly catalogued individual pathways or interventions, this review integrates disease-stage-specific pathobiology, evidence hierarchy, and translational readiness within a unified framework. Among clinically evaluated interventions, Huangqi-based preparations and Qidong Yixin Oral Liquid have comparatively broader—although still low-certainty—human evidence for adjunctive improvements in symptoms, myocardial injury markers, inflammatory indices, and selected functional outcomes. By contrast, oxymatrine and berberine are supported mainly by repeated preclinical studies. Across these interventions, the most consistently implicated targets include NF-κB, NLRP3, JAK/STAT, PI3K/Akt, and TGF-β/Smad signaling. Major knowledge gaps include small and heterogeneous clinical studies, variable formulations and quality control, incomplete pharmacokinetic characterization, limited disease-stage and biomarker stratification, and scarce long-term efficacy and safety data. Future translation should prioritize standardized products, exposure-response evaluation, biomarker-guided patient selection, and rigorous multicenter randomized trials. Overall, natural products and herbal medicines should currently be regarded as promising adjunctive candidates whose clinical value depends on stronger, stage-specific, and methodologically robust evidence.