Effects of shokyo (Zingiberis Rhizoma) and kankyo (Zingiberis Processum Rhizoma) on prostaglandin E2 production in lipopolysaccharide-treated mouse macrophage RAW264.7 cells

Toshiaki Ara; Masanori Koide; Hiroyuki Kitamura; Norio Sogawa

doi:10.7717/peerj.7725

Effects of shokyo (Zingiberis Rhizoma) and kankyo (Zingiberis Processum Rhizoma) on prostaglandin E₂ production in lipopolysaccharide-treated mouse macrophage RAW264.7 cells

PeerJ. 2019 Sep 17:7:e7725. doi: 10.7717/peerj.7725. eCollection 2019.

Authors

Toshiaki Ara¹, Masanori Koide², Hiroyuki Kitamura³, Norio Sogawa¹

Affiliations

¹ Department of Pharmacology, Matsumoto Dental University, Shiojiri, Nagano, Japan.
² Institute for Oral Science, Matsumoto Dental University, Shiojiri, Nagano, Japan.
³ Matsumoto Dental University Hospital, Shiojiri, Nagano, Japan.

Abstract

We previously reported that shokyo and kankyo, which are water-extracted fractions of ginger, reduced LPS-induced PGE₂ production in human gingival fibroblasts. In this study, we examined the effects of these herbs on LPS-treated mouse macrophage RAW264.7 cells. Both shokyo and kankyo reduced LPS-induced PGE₂ production in a concentration-dependent manner. Shokyo and kankyo did not inhibit cyclooxygenase (COX) activity, nor did they alter the expression of molecules in the arachidonic acid cascade. In addition, these herbs did not alter NF-κB p65 translocation into nucleus, or phosphorylation of p65 or ERK. These results suggest that shokyo and kankyo inhibit cPLA₂ activity. Although 6-shogaol produced similar results to those of shokyo and kankyo, the concentration of 6-shogaol required for the reduction of PGE₂ production were higher than those of 6-shogaol in shokyo and kankyo. Therefore, several gingerols and shogaols other than 6-shogaol may play a role in the reduction of LPS-induced PGE₂ production. Thus, 6-shogaol, and other gingerols and shogaols inhibit cPLA₂ activity and reduce LPS-induced PGE₂ production via a different mechanism from traditional anti-inflammatory drugs. Moreover, kampo medicines that contain shokyo or kankyo are considered to be effective for inflammatory diseases.

Keywords: 6-shogaol; Antiinflammatory effect; Arachidonic acid cascade; Herb; Kampo medicine; Kankyo; Macrophage; Prostaglandin E2; Shokyo.

Grants and funding

The study was supported by funding from JSPS KAKENHI Grant Number JP16H05144, the Nagano Society for the Promotion of Science, and a Scientific Research Special Grant from Matsumoto Dental University. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.