Cardioprotective Effect of Rhapontigenin in Isoproterenol-Induced Myocardial Infarction in a Rat Model

<b><i>Background/Aims:</i></b> Rhapontigenin (RPG) is a stilben derivative and is known to bear several effects such as antiallergic, anticoagulative, hypoglycemic, antiangiogenic, and purgative. The investigation was conducted to evaluate the cardioprotective efficacy of RPG in rats having acute myocardial infarction (MI) induced by isoproterenol (ISO). <b><i>Methods:</i></b> Animals were divided into 6 groups: group I (control group), group II (ISO-treated), group III (1.0 mg/kg/day RPG and ISO-treated), group IV (2.5 mg/kg/day RPG and ISO-treated), group V (5.0 mg/kg/day RPG and ISO-treated), and group VI (treated with RPG 5.0 mg/kg/day). Various cardiac stress markers, including infarct size and heart/body weight index, were investigated in animals with ISO-induced MI, such as inducible nitric oxide synthase (iNOS), creatinine kinase (CK), lactate dehydrogenase (LD), cardiac troponin-T (CTT), superoxide dismutase (SOD), and malondialdehyde. INOS, p38, caspase-3, and connexin 43 expressions were analyzed in animals. Inflammatory mediators, tissue necrosis factor-α (TNF-α) and interleukin-6 (IL-6), were detected in serum of experimental animals. <b><i>Results:</i></b> Group I animals indicated normal levels of biochemical parameters, whereas group II animals indicated high levels of these parameters and successful induction of MI. Pretreatment of animal groups III, IV, and V with RPG revealed amelioration of infarct size, heart/body weight index, CK, LD, CTT in rats, whereas group VI animals were treated only with RPG (5.0 mg/kg/day) and not with ISO. Levels of TNF-α, IL-6, MD, SOD, p38, and iNOS expressions were significantly downregulated by RPG administration (5.0 mg/kg/day). <b><i>Conclusion:</i></b> RPG ameliorates MI caused by ISO in rats and provides cardioprotective effect, via anti-inflammatory, antioxidant, and antiapoptotic effect.