Anti-inflammatory activity of the dietary supplement Houttuynia cordata fermentation product in RAW264.7 cells and Wistar rats

PLoS One. 2020 Mar 25;15(3):e0230645. doi: 10.1371/journal.pone.0230645. eCollection 2020.

Abstract

Houttuynia cordata Thunb. has been used as a traditional medicine to treat a variety of ailments in Asian countries such as China, Japan, South Korea, and Thailand. In Thailand, H. cordata fermentation products (HCFPs) are commercially produced and popularly consumed throughout the country without experimental validation. Anti-inflammatory activity of H. cordata fresh leaves or aerial parts has previously been reported, however, the anti-inflammatory activity of the commercially available HCFPs produced by the industrialized process has not yet been investigated. The aim of this study was to evaluate in vitro and in vivo anti-inflammatory potential of the selected industrialized HCFP. LPS-induced RAW264.7 and carrageenan-induced paw edema models were used to evaluate the anti-inflammatory activity of HCFP. The phenolic acid components of HCFP aqueous and methanolic extracts were investigated using HPLC analysis. In RAW264.7 cells, the HCFP aqueous and methanolic extracts reduced NO production and suppressed LPS-stimulated expression of PGE2, iNOS, IL-1β, TNF-α and IL-6 levels in a concentration-dependent manner, however, less effect on COX-2 level was observed. In Wistar rats, 3.08 and 6.16 mL/kg HCFP reduced paw edema after 2 h carrageenan stimulation, suggesting the second phase anti-edematous effect similar to diclofenac (150 mg/kg). Whereas, 6.16 mL/kg HCFP also reduced paw edema after 1 h carrageenan stimulation, suggesting the first phase anti-edematous effect. Quantitative HPLC revealed the active phenolic compounds including syringic, vanillic, p-hydroxybenzoic and ferulic acids, which possess anti-inflammatory activity. Our results demonstrated for the first time the anti-inflammatory activity of the industrialized HCFP both in vitro and in vivo, thus validating its promising anti-inflammation potential.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Anti-Inflammatory Agents / chemistry
  • Anti-Inflammatory Agents / pharmacology*
  • Anti-Inflammatory Agents / therapeutic use
  • Cell Survival / drug effects
  • Dietary Supplements / analysis*
  • Edema / chemically induced
  • Edema / drug therapy
  • Houttuynia / chemistry
  • Houttuynia / metabolism*
  • Interleukin-1beta / genetics
  • Interleukin-1beta / metabolism
  • Lipopolysaccharides / toxicity
  • Macrophages / cytology
  • Macrophages / drug effects
  • Macrophages / metabolism
  • Male
  • Mice
  • Nitric Oxide / metabolism
  • Nitric Oxide Synthase Type II / genetics
  • Nitric Oxide Synthase Type II / metabolism
  • Phenols / analysis
  • Plant Components, Aerial / chemistry
  • Plant Components, Aerial / metabolism
  • Plant Extracts / chemistry
  • Plant Leaves / chemistry
  • Plant Leaves / metabolism
  • RAW 264.7 Cells
  • Rats
  • Rats, Wistar

Substances

  • Anti-Inflammatory Agents
  • Interleukin-1beta
  • Lipopolysaccharides
  • Phenols
  • Plant Extracts
  • Nitric Oxide
  • Nitric Oxide Synthase Type II

Grants and funding

This study was supported by the Research and Researcher for Industry (RRi) project, Thailand Research Fund (TRF), which was cooperated with the Prolac (Thailand) Co., Ltd., Lamphun Province, Thailand. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. However, the funders have been informed and agreed on publishing a manuscript, sharing data and materials.