BackgroundNecroptosis, a novel form of programmed cell death wherein the necrotic morphology is characterized by swelling of the cells, rupture of the plasma membrane, and dysfunction of the organelle, has been always observed in cardiovascular diseases. Sugarcane leaf polysaccharide (SLP) are primary components present in sugarcane leaves that exert cardiovascular protective effects. However, the positive effect of SLP and underlying mechanisms in myocardial ischemia-reperfusion (MI/R) remain unexplored. AimIn this study, the protective effects of SLP on MI/R injury were investigated under in vitro and in vivo conditions. MethodsThe protective effects of SLP on MI/R injury were assessed using tertiary butyl hydrogen peroxide (TBHP)–stimulated-H9c2 cells in the in vitro assay and using Sprague Dawley rats in the in vivo assay. ResultsIn vitro, SLP significantly reversed TBHP-induced H9c2 cell death by inhibiting necroptosis and oxidative stress. SLP exerted antioxidant activity through the Nrf2/HO-1 pathway. SLP suppressed necroptosis by decreasing phosphorylation of RIP1, RIP3, and MLKL in TBHP-stimulated H9c2 cells. In vivo, SLP attenuated MI/R injury by decreasing the myocardial infarct area; increasing myeloperoxidase and superoxide dismutase levels; and reducing malondialdehyde, interleukin-6, and tumor necrosis factor-α levels.