ABSTRACT
Isoproterenol (ISO), a chemically synthesized catecholamine, belongs to ß-adrenoceptor agonist used to treat bradycardia. The ß-adrenergic agonist is an essential regulator of myocardial metabolism and contractility; however, excessive exposure to ISO can initiate oxidative stress and inflammation. This study aims to investigate the molecular mechanisms underlying ISO-induced cardiac remodeling, the protective efficacy of resveratrol (RSVR), and its liposomal formulation (L-RSVR) against such cardiac change. Wistar albino rats were evenly divided into 4 groups. Control group, ISO group received ISO (50 mg/kg, s.c.) twice a week for 2 weeks, and RSVR- and L-RSVR-treated groups in which rats received either RSVR or L-RSVR (20 mg/kg/day, p.o.) along with ISO for 2 weeks. ISO caused a significant elevation of the expression levels of BAX and MEF2 mRNA, S100A1 and cytochrome C proteins, as well as DNA fragmentation in cardiac tissue compared to the control group. Treatment with either RSVR or L-RSVR for 14 days significantly ameliorated the damage induced by ISO, as evidenced by the improvement of all measured parameters. The present study shows that L-RSVR provides better cardio-protection against ISO-induced cardiac injury in rats, most likely through modulation of cardiac S100A1 protein expression and inhibition of inflammation and apoptosis.
ABSTRACT
Background and Objective: Isoproterenol (ISO) is a non-selective ß-adrenergic receptor agonist. It can be used to treat bradycardia and cardiogenic shock. Despite its usefulness, the overstimulation of ß-receptors by ISO can cause "cardiorenal syndrome," a term used to describe heart and kidney damage. Resveratrol (RES), a natural polyphenol, has marked anti-inflammatory and antioxidant activities. The present work was designed to study the protective efficacy of liposomal resveratrol (L-RES) against ISO-induced kidney injury. Materials and Methods: The kidney injury was induced in rats by administering ISO (50 mg/kg, s.c.) twice a week for 2 weeks. RES and L-RES were administered at a dose (20 mg/kg/ day, p.o.) along with ISO for 2 weeks. Inflammatory and apoptotic biomarkers were analyzed, which were validated using histochemical analysis. Results: ISO caused renal dysfunction, which manifested as elevated urea, creatinine and uric acid, besides cystatin c and MAPK protein overexpression. In addition, ISO induced gene expression of Fas and lipocalin-2 and provoked genomic DNA fragmentation in renal tissues as compared with the control group. Histological examination confirmed morphological alterations of the kidney tissues obtained from the ISO group. Concurrent treatment of either RES or L-RES with ISO significantly ameliorated kidney damage as demonstrated by the improvement of all measured parameters with the best results for L-RES. The histopathological findings were correlated with the above biochemical parameters. Conclusion: L-RES could be a promising approach for the prevention of kidney injury induced by ISO, most likely via the downregulation of MAPK, cystatin c, Fas, and lipocalin-2.
