Reactivation and infection with cytomegalovirus (CMV) are frequently observed in recipients of solid organ transplants, bone marrow transplants, and individuals with HIV infection. This presents an increasing risk of allograft rejection, opportunistic infection, graft failure, and patient mortality. Among immunocompromised hosts, interstitial pneumonia is the most critical clinical manifestation of CMV infection. Recent studies have demonstrated the potential therapeutic benefits of exosomes derived from mesenchymal stem cells (MSC-exos) in preclinical models of acute lung injury, including pneumonia, ARDS, and sepsis. However, the role of MSC-exos in the pathogenesis of infectious viral diseases, such as CMV pneumonia, remains unclear. In a mouse model of murine CMV-induced pneumonia, we observed that intravenous administration of mouse MSC (mMSC)-exos reduced lung damage, decreased the hyperinflammatory response, and shifted macrophage polarization from the M1 to the M2 phenotype. Treatment with mMSC-exos also significantly reduced the infiltration of inflammatory cells and pulmonary fibrosis. Furthermore, in vitro studies revealed that mMSC-exos reversed the hyperinflammatory phenotype of bone marrow-derived macrophages infected with murine CMV. Mechanistically, mMSC-exos treatment decreased activation of the NF-κB/NLRP3 signaling pathway both in vivo and in vitro. In summary, our findings indicate that mMSC-exo treatment is effective in severe CMV pneumonia by reducing lung inflammation and fibrosis through the NF-κB/NLRP3 signaling pathway, thus providing promising therapeutic potential for clinical CMV infection.

Alpinetin, a distinctive plant-derived dihydroflavonoid from cardamom seeds, represents an under-explored chemical scaffold compared to common flavonoids like quercetin or kaempferol. While many flavonoids have shown general cardioprotective potential, the structural specificity of alpinetin may confer unique pharmacological advantages. Inspired by its historical use in traditional Chinese medicine for cardiac discomfort, this study systematically investigated its efficacy against acute myocardial infarction (AMI). In a rat AMI model, alpinetin demonstrated superior infarct size reduction and functional recovery relative to other tested flavonoids. It significantly attenuated key AMI pathologies—including inflammatory infiltration, CD68+ macrophage activation, IL-6/TNF-α release, collagen deposition, and cardiomyocyte apoptosis—more effectively than common flavonoid benchmarks. Mechanistically, alpinetin selectively targeted the TLR4/MyD88/NF-κB signaling axis with notable potency, a pathway not robustly modulated by other flavonoids in the screening. These findings not only validate the traditional wisdom of cardamom but also establish alpinetin as a structurally and mechanistically distinct flavonoid with high translational promise, offering a new candidate for the targeted treatment of ischemic heart disease.