Abstract
Accumulating evidence demonstrates that Macleaya cordata extract exerts antiviral and anti-inflammatory effects in various diseases. The present study aimed to investigate the potential effects of M. cordata on rotavirus SA11-induced diarrhea in mice. Diarrhea severity, levels of inflammatory cytokines, histological changes in the small intestine and the underlying mechanisms were evaluated in rotavirus-stimulated mice treated with 1, 2 and 4 mg/kg/day M. cordata or 4 mg/kg/day ribavirin (positive control). M. cordata treatment effectively ameliorated rotavirus-induced diarrhea in a dose-dependent manner by decreasing viral RNA levels. In addition, M. cordata reduced the release of pro-inflammatory cytokines including migration inhibitory factor, interleukin (IL)-8, IL-β, interferon-γ and tumor necrosis factor-α, and elevated the secretion of the anti-inflammatory cytokine IL-10 following rotavirus infection. M. cordata inhibited intestinal epithelial cell apoptosis and improved intestinal inflammation after rotavirus infection. The study also revealed that M. cordata exerted antiviral and anti-inflammatory effects on rotavirus-induced diarrhea by suppressing the Janus kinase 2 (JAK2)/STAT3 pathway, as reflected by decreased protein expression of phosphorylated (p)-JAK2 and p-STAT3. Overall, M. cordata effectively inhibited the inflammation caused by rotavirus, which was closely associated with the suppression of JAK2/STAT3 phosphorylation. These data suggested that M. cordata may be applied as a treatment for rotavirus-induced diarrhea.