Crocetin Exerts a Cardio-protective Effect on Mice with Coxsackievirus B3-induced Acute Viral Myocarditis

Previous research has proven that coxsackievirus B3 (CVB3) is broadly considered virus used in the experimental model of animals, which causes myocarditis in humans. To investigate whether there exists a cardio-protective effect of crocetin in an experimental murine model of acute viral myocarditis (AVM). Male BALB/c mice were randomly assigned to three groups: control, myocarditis treated with placebo and myocarditis treated with crocetin (n = 40 animals per group). Myocarditis was established by intraperitoneal injection with CVB3. Twenty-four hours after infection, crocetin was intraperitoneally administered for 14 consecutive days. Twenty mice were randomly selected from each group to monitor a 14-day survival rate. On day 7 and day 14, eight surviving mice from each group were sacrificed and their hearts and blood were obtained to perform serological and histological examinations. Expression of ROCKs, interleukin-17 (IL-17), interleukin-1 beta (IL-1 beta), tumor necrosis factor-alpha (TNF alpha), ROR gamma t, and Foxp3 was quantified by RT-PCR. Plasma levels of TNF alpha, IL-1 beta and IL-17 were measured by ELISA. In addition, protein levels of IL-17 and ROCK2 in cardiac tissues were analyzed by Western blot. Crocetin treatment significantly increased survival, attenuated myocardial necrotic lesions, reduced CVB3 replication and expression of ROCK2 and IL-17 in the infected hearts. ROCK pathway inhibition was cardio-protective in viral myocarditis with increased survival, decreased viral replication, and inflammatory response. These findings suggest that crocetin is a potential therapeutic agent for patients with viral myocarditis.