Vincristine attenuates isoprenaline-induced cardiac hypertrophy in male Wistar rats via suppression of ROS/NO/NF-κB signalling pathways

Vincristine (VCR), a vinca alkaloid with anti-tumor and anti-oxidant properties, is acclaimed to possess cardioprotective action. However, the molecular mechanism underlying this protective effect remains unknown. This study investigated the effects of VCR on isoprenaline (ISO), a beta-adrenergic receptor agonist, induced cardiac hypertrophy in male Wistar rats. Animals were pre-treated with ISO (1 mg/kg) intraperitoneally for 14 days before VCR (25 mu g/kg) intraperitoneal injection from days 1 to 28. Thereafter, mechanical, and electrical activities of the hearts of the rats were measured using a non-invasive blood pressure monitor and an electrocardiograph, respectively. After which, the heart was homogenized, and supernatants were assayed for contractile proteins: endothelin-1, cardiac troponin-1, angiotensin-II, and creatine kinase-MB, with markers of oxidative/nitrergic stress (SOD, CAT, MDA, GSH, and NO), inflammation (TNF-a and IL-6, NF-kB), and caspase-3 indicative of VCR reduced elevated blood pressure and reversed the abnormal electrocardiogram. ISO-induced increased endothelin-1, cardiac troponin-1, angiotensin-II, and creatine phosphokinase-MB, which were reversed by VCR. ISO also increased TNF-alpha, IL-6, NF-kB expression with increased caspase-3-mediated apoptosis in the heart. However, VCR reduced ISO-induced inflammation and apoptosis, with improved endogenous antioxidant agents (GSH, SOD, CAT) relative to ISO controls. Moreso, VCR, protected against ISO-induced histoarchitectural degeneration of cardiac myofibre. The result of this study revealed that VCR treatment significantly reverses ISO-induced cardiac hypertrophic phenotypes, via mechanisms connected to improved levels of proteins involved in excitation-contraction, and suppression of oxido-inflammatory and apoptotic pathways.