Watsonianone A from Rhodomyrtus tomentosa Fruit Attenuates Respiratory-Syncytial-Virus-Induced Inflammation In Vitro

J Agric Food Chem. 2017 May 3;65(17):3481-3489. doi: 10.1021/acs.jafc.7b00537. Epub 2017 Apr 24.

Abstract

Respiratory syncytial virus (RSV) is one of the most common respiratory pathogens. Immoderate inflammation plays a great role in causing RSV-induced diseases. In the present study, watsonianone A, isolated from the fruit of Rhodomyrtus tomentosa (Ait.) Hassk, was found to show a good inhibitory effect on RSV-induced NO production, with a half-maximal inhibitory concentration of 37.2 ± 1.6 μM. Enzyme-linked immunosorbent assay and fluorescence quantitative polymerase chain reaction analyses indicated that watsonianone A markedly reduced both mRNA and protein levels of tumor necrosis factor α, interleukin 6, and monocyte chemoattractant protein 1 in RSV-infected RAW264.7 cells. Mechanistically, watsonianone A inhibited nuclear factor κB (NF-κB) activation by suppressing IκBα phosphorylation. Further analysis revealed that watsonianone A activated the thioredoxin system and decreased intracellular reactive oxygen species (ROS) levels, which are closely associated with NF-κB activation in RSV-infected cells. These results reveal that watsonianone A can attenuate RSV-induced inflammation via the suppression of ROS-sensitive inflammatory signaling.

Keywords: ROS; Rhodomyrtus tomentosa; inflammation; respiratory syncytial virus; watsonianone A.

MeSH terms

  • Cyclohexanones / pharmacology*
  • Fruit / chemistry*
  • Humans
  • I-kappa B Proteins / genetics
  • I-kappa B Proteins / immunology
  • Interleukin-6 / genetics
  • Interleukin-6 / immunology
  • Myrtaceae / chemistry*
  • NF-kappa B / genetics
  • NF-kappa B / immunology
  • Plant Extracts / pharmacology*
  • Reactive Oxygen Species / immunology
  • Respiratory Syncytial Virus Infections / drug therapy
  • Respiratory Syncytial Virus Infections / immunology*
  • Respiratory Syncytial Virus Infections / virology
  • Respiratory Syncytial Viruses / drug effects*
  • Respiratory Syncytial Viruses / physiology
  • Tumor Necrosis Factor-alpha / genetics
  • Tumor Necrosis Factor-alpha / immunology

Substances

  • Cyclohexanones
  • I-kappa B Proteins
  • IL6 protein, human
  • Interleukin-6
  • NF-kappa B
  • Plant Extracts
  • Reactive Oxygen Species
  • Tumor Necrosis Factor-alpha
  • watsonianone A