Baicalein attenuates angiotensin II-induced cardiac remodeling via inhibition of AKT/mTOR, ERK1/2, NF-κB, and calcineurin signaling pathways in mice

Am J Hypertens. 2015 Apr;28(4):518-26. doi: 10.1093/ajh/hpu194. Epub 2014 Oct 31.

Abstract

Background: Baicalein, a specific lipoxygenase (LOX) inhibitor, has anti-inflammatory and antioxidant effects. However, the functional role of baicalein in angiotensin II (Ang II)-induced hypertension and cardiac remodeling remains unclear. Here we investigated the effect of baicalein on cardiac hypertrophy and fibrosis and the underlying mechanism.

Methods: Wild-type (WT) mice were injected with Ang II (1,200ng/kg/min) alone or together with 12/15-LOX inhibitor baicalein (25mg/kg) for 14 days. Histological examinations were performed on heart sections with hematoxylin and eosin, Masson's trichrome, wheat germ agglutinin staining, and immunohistochemistry. The messenger RNA (mRNA) expression of cytokines and protein levels were detected by real-time polymerase chain reaction (PCR) and western blot analysis respectively.

Results: Ang II infusion significantly increased blood pressure but decreased cardiac contractile function reflected by fractional shortening% and ejection fraction% compared with saline-treated mice. Moreover, Ang II infusion resulted in marked cardiac hypertrophy and fibrosis, promoted accumulation of macrophages and T cells, the expression of proinflammatory cytokines and malondialdehyde (MDA) production. However, these actions were markedly reversed by administration of baicalein in mice. Mechanistically, the protective effects of baicalein were associated with the inhibition of inflammation, oxidative stress, and multiple signaling pathways (AKT/mTOR, ERK1/2, nuclear factor-κB (NF-κB), and calcineurin) in the Ang II-treated mice.

Conclusions: This study demonstrates that baicalein can significantly ameliorate Ang II-induced hypertension and cardiac remodeling, and may be a novel therapeutic drug for prevention of hypertensive heart diseases.

Keywords: 12/15-lipoxygenase; angiotensin II; baicalein; blood pressure; cardiac remodeling; hypertension; signaling pathways..

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Angiotensin II*
  • Animals
  • Calcineurin Inhibitors / pharmacology*
  • Cytokines / genetics
  • Cytokines / metabolism
  • Disease Models, Animal
  • Enzyme Activation
  • Fibrosis
  • Flavanones / pharmacology*
  • Gene Expression Regulation
  • Hypertension / chemically induced
  • Hypertension / enzymology
  • Hypertension / physiopathology
  • Hypertension / prevention & control
  • Hypertrophy, Left Ventricular / chemically induced
  • Hypertrophy, Left Ventricular / enzymology
  • Hypertrophy, Left Ventricular / genetics
  • Hypertrophy, Left Ventricular / physiopathology
  • Hypertrophy, Left Ventricular / prevention & control*
  • Inflammation Mediators / metabolism
  • Lipoxygenase Inhibitors / pharmacology*
  • Male
  • Mice, Inbred C57BL
  • Mitogen-Activated Protein Kinase 1 / metabolism*
  • Mitogen-Activated Protein Kinase 3 / metabolism*
  • Myocardium / enzymology*
  • Myocardium / pathology
  • NF-kappa B / metabolism*
  • Oxidative Stress / drug effects
  • Phosphorylation
  • Proto-Oncogene Proteins c-akt / metabolism*
  • Signal Transduction / drug effects
  • TOR Serine-Threonine Kinases / metabolism*
  • Time Factors
  • Ventricular Function, Left / drug effects*
  • Ventricular Remodeling / drug effects*

Substances

  • Calcineurin Inhibitors
  • Cytokines
  • Flavanones
  • Inflammation Mediators
  • Lipoxygenase Inhibitors
  • NF-kappa B
  • Angiotensin II
  • baicalein
  • mTOR protein, mouse
  • Proto-Oncogene Proteins c-akt
  • TOR Serine-Threonine Kinases
  • Mapk1 protein, mouse
  • Mitogen-Activated Protein Kinase 1
  • Mitogen-Activated Protein Kinase 3