NOVEL ITACONATE DERIVATIVE ATTENUATES ISOPROTERENOL INDUCED CARDIOTOXICITY IN EXPERIMENTAL ANIMALS: A MOLECULAR PATHWAY INSIGHT

Abstract

Objective: 4-octyl itaconate (4-OI) is a potential drug for the treatment of myocardial infarction on account of its potent anti-inflammatory, antioxidant and anti-apoptotic properties. Thus, we hypothesise that 4-OI may attenuate isoproterenol(ISO) induced cardiotoxicity by modulating several molecular pathways in Wistar albino rats. Design and method: After getting approval from animal ethics committee(278/IAEC/2021), the experimental work was started. ISO 5mg/kg s.c., was administered daily for 15 days. Adult male rats were randomly divided into 5 groups (n=6): normal control group, ISO control group, treatment control groups. 4-OI was administered i.p. at 3 different doses (2.5,5,10 mg/kg) to rats from day 1 and continued for 15 days along with ISO. On the 16th day, surgery was performed, right carotid artery was cannulated for recording of hemodynamic parameters. Blood was drawn using cardiac puncture and rats were then sacrificed, one portion of the heart was immediately stored in 10% formalin for histopathological evaluation and second portion was kept in -80 degree C for further studies. Serum was stored for biochemical, pro-inflammatory cytokines estimation (TNF, IL-6, IL1 beta) and cardiac injury markers (CKMB, LDH). Results: 4-OI improved cardiac function and attenuated pathological changes as seen microscopically in the H&E stained heart tissue sections. On ultrastructural evaluation, 4-OI treatment (5, 10mg/kg) groups presented with lesser nuclear condensation and mitochondrial swelling, as compared to the ISO control group. A significant decline in the serum and tissue levels of cardiac injury markers (CK-MB, LDH) and inflammatory markers were observed in 4-OI (5,10mg/kg) treated rats, as compared to ISO control group. Additionally, 4-OI suppressed oxidative stress and apoptosis, along with an increased PPAR-gamma expression. Molecular pathway assessment revealed that at the dose of 10mg/kg, 4-OI reduced the expression of NFkappaB, IKK-beta and enhanced the expression of Nrf-2 and HO-1. On analysis of the inflammatory MAPK pathway, expression of the pro-survival kinase ERK was also increased while JNK and p38 protein expressions were reduced. Conclusions: 4-OI at a dose of 10mg/kg mitigates myocardial toxicity in ISO treated rats by maintaining morphological structure of heart tissue with oxidative stress profile and reduced inflammation