Rani N, Bharti S, Bhatia J, Tomar A, Nag TC, Ray R, Arya DS. Inhibition of TGF-β by a novel PPAR-γ agonist, chrysin, salvages β-receptor stimulated myocardial injury in rats through MAPKs-dependent mechanism.
Nutr Metab (Lond) 2015;
12:11. [PMID:
25774203 PMCID:
PMC4359541 DOI:
10.1186/s12986-015-0004-7]
[Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2014] [Accepted: 02/06/2015] [Indexed: 12/19/2022] Open
Abstract
Background
Pharmacological stimulation of peroxisome proliferator-activated receptor-gamma (PPAR-γ) has been recognized as a molecular switch in alleviating myocardial injury through modulating oxidative, inflammatory and apoptotic signaling pathways. This study was designed to elucidate the effect of chrysin, a novel PPAR-γ agonist and its functional interaction with TGF-β/MAPKs in isoproterenol-challenged myocardial injury in rats.
Methods
Male Wistar Albino rats were either subjected to vehicle (1.5 mL/kg, p.o.) or chrysin (15–60 mg/kg, p.o.) for 28 days. Isoproterenol (85 mg/kg, s.c.) was administered to rats on 27th and 28th day to induce myocardial injury.
Results
Chrysin dose dependently improved ventricular (±LVdP/dtmax and LVEDP) and hemodynamic (SAP, MAP and DAP) dysfunction in isoproterenol-insulted rats. This beneficial effect of chrysin was well supported with increased expression of PPAR-γ and decreased expression of TGF-β as evidenced by western blotting and immunohistochemistry analysis. Moreover, downstream signaling pathway of TGF-β viz. P-ERK½/ERK½ activation and P-JNK/JNK, P-p38/p38 and MMP-2 inhibition were also observed. Chrysin also attenuated NF-κBp65 and IKK-β expressions, TNF-α level and TUNEL positivity thereby validating its anti-inflammatory and anti-apoptotic properties. Additionally, chrysin in a dose dependent fashion improved NO level, redox status of the myocardium (GSH and MDA levels and SOD, GSHPx and CAT activities), cardiac injury markers (CK-MB and LDH levels) and oxidative DNA damage marker (8-OHdG level) and displayed preservation of subcellular and ultrastructural components.
Conclusion
We established that activation of PPAR-γ and inhibition of TGF-β via MAPKs dependent mechanism is critical for cardioprotective effect of chrysin.
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