Inhibitory Effect of the Ethanol Extract of a Rice Bran Mixture Comprising Angelica gigas, Cnidium officinale, Artemisia princeps, and Camellia sinensis on Brucella abortus Uptake by Professional and Nonprofessional Phagocytes

J Microbiol Biotechnol. 2017 Oct 28;27(10):1885-1891. doi: 10.4014/jmb.1704.04064.

Abstract

In this study, we evaluated the inhibitory effect of a rice bran mixture extract (RBE) on Brucella abortus pathogenesis in professional (RAW 264.7) and nonprofessional (HeLa) phagocytes. We fermented the rice bran mixture and then extracted it with 50% ethanol followed by gas chromatography-mass spectrometry to identify the components in RBE. Our results clearly showed that RBE caused a significant reduction in the adherence of B. abortus in both cell lines. Furthermore, analysis of phagocytic signaling proteins by western blot assay revealed that RBE pretreatment resulted in inhibition of phosphorylation of JNK, ERK, and p38, leading to decline of internalization compared with the controls. Additionally, the intensity of F-actin observed by fluorescence microscopy and FACS was remarkably reduced in RBE-pretreated cells compared with control cells. However, the intracellular replication of B. abortus within phagocytes was not affected by RBE. Taken together, these findings suggest that the phagocytic receptor blocking and suppressive effects of RBE on the MAPK-linked phagocytic signaling pathway could negatively affect the invasion of B. abortus into phagocytes.

Keywords: B. abortus; pathogenesis; phagocyte; phagocytic signaling; rice bran mixture extract.

MeSH terms

  • Actins / metabolism
  • Adhesins, Bacterial / drug effects
  • Angelica / chemistry*
  • Animals
  • Anti-Bacterial Agents / pharmacology
  • Artemisia / chemistry*
  • Brucella abortus / drug effects*
  • Brucella abortus / growth & development
  • Brucella abortus / pathogenicity
  • Brucellosis
  • Camellia sinensis / chemistry*
  • Cnidium / chemistry*
  • Ethanol / chemistry
  • Gas Chromatography-Mass Spectrometry
  • HeLa Cells / drug effects
  • Humans
  • MAP Kinase Signaling System / drug effects
  • Mice
  • Oryza / chemistry*
  • Phagocytes / microbiology
  • Phagocytosis / drug effects*
  • Phosphorylation / drug effects
  • Plant Extracts / antagonists & inhibitors*
  • RAW 264.7 Cells / drug effects
  • Signal Transduction / drug effects

Substances

  • Actins
  • Adhesins, Bacterial
  • Anti-Bacterial Agents
  • Plant Extracts
  • Ethanol