Abstract
Epidermal growth factor receptor (EGFR) related reactive oxygen species (ROS) generation results in myocardial damage. We aimed to investigate the role of gefitinib (EGFR-tyrosine kinase inhibitor) in diabetic cardiomyopathy (DbCM).
DbCM was induced by injecting streptozotocin (55 mg/kg for 5 consecutive days) to C57/BL6 mice intraperitoneally. Diabetic C57/BL6 mice (fasting blood glucose level ≥ 250 mg/dl) were allocated into four study groups and treated with two doses of gefitinib (30 mg/kg and 350 mg/kg per day) as well as ramipril (3 mg/kg/day) for four weeks.
We observed a significant correlation between persistent hyperglycaemia with cardiac remodeling and alterations in myocardial architecture. Gefitinib significantly prevented lipid peroxidation (MDA), damage of antioxidant enzymes like superoxide dismutase (SOD), Catalase, glutathione (GSH) and thioredoxin reductase (TrxR). Gefitinib also prevented hypertrophy of myocardium evidenced by reduced heart weight to body weight ratio and TGF‑β related collagen deposition. Gefitinib maintained cardiac biomarkers like lactate dehydrogenase (LDH), Creatine Kinase‑MB, brain natriuretic peptide (BNP) and cardiac Troponin‑I (cTroponinI) indicating reduced myocardial damage. Decreased sarcoplasmic endoplasmic reticulum Ca2 + ATPase2a (SERCA2a) and sodium‑calcium exchanger-1 (NCX1) protein depletion after gefitinib administration indicated improved Ca2+ homeostasis during myocardial contractility. Histopathology and transmission electron microscopy clearly showed almost normal myofibrils and mitochondrial arrangements in gefitinib treated mice.
Our findings suggest that gefitinib protects myocardial damage in DbCM via balancing oxidant-antioxidant system, decreased collagen deposition as well as improved CKMB, BNP, cTroponinI and SERCA2a/NCX-1. Thereby, it indicated that gefitinib may be a potential therapeutic drug for treating DbCM.