A combination of alkaloids and saponins attenuates coxsackievirus B3‑induced acute myocarditis in mice via NF‑κB signaling.

Timely treatment of viral myocarditis (VMC), a form of cardiac inflammation caused by viral infections, can reduce the occurrence of dilated cardiomyopathy and sudden death. Our previous study demonstrated the anti-inflammatory and anti-fibrotic effects of KX, a combination of alkaloids and saponins, on an autoimmune myocarditis model . The present study explored the effects of KX on coxsackievirus B3 (CVB3)-induced acute VMC in mice. Mice were randomly divided into four groups: Control, VMC, KX-high (275 mg/kg) and KX-low (138 mg/kg). Mice in the VMC, KX-high and KX-low groups received injections of CVB3 to establish the VMC model, and those in the KX-high and KX-low groups also received KX by gavage (10 ml/kg) 2 h after virus injection until euthanasia was performed on day 7 or 21. Mice in the control group received an equal KX volume of purified water. The levels of lactate dehydrogenase (LDH), creatine kinase-myocardial band (CK-MB), cardiac troponin I (cTn-I), IL-1β, IL-6, TNF-α and high-sensitive C-reactive protein (hs-CRP) in mouse serum was measured using ELISA. Myocardial tissue structure and degree of injury were observed using hematoxylin and eosin staining. Western blotting and reverse transcription-quantitative PCR were performed to detect the expression levels of NF-κB pathway-related mRNA and protein in myocardial tissue. The results showed that the inflammation and myocardial damage levels of the mice in the VMC group were higher at 7 days than those at 21 days. At both 7 and 21 days, KX decreased the serum CK-MB, LDH, cTn-I, IL-6, TNF-α and hs-CRP levels, and inhibited NF-κB pathway-related mRNA and protein expression in the myocardium of mice. These findings indicated that KX may reduce the inflammatory response and attenuate the pathological damage in the acute and subacute phases of CVB3-induced VMC through the NF-κB pathway.