Preliminary exploration on anti-inflammatory mechanism of Corilagin (beta-1-O-galloyl-3,6-(R)-hexahydroxydiphenoyl-d-glucose) in vitro

Corilagin (beta-1-O-galloyl-3,6-(R)-hexahydroxydiphenoyl-d-glucose) is a novel member of the tannin family which has been discovered from many medicinal plants and has been confirmed in many pharmacological activities. However, the purified Corilagin that was used in experiment is rare, and the anti-inflammatory mechanism of Corilagin has not been investigated clearly. This study is to explore the inner anti-inflammatory mechanism of Corilagin. Inflammatory cellular model was established by lipopolysaccharide (LPS) interfering on RAW264.7 cell line. Levels of TNF-α, IL-1β, IL-6, NO and IL-10 in supernatant, mRNA expression of TNF-α, COX-2, iNOS and HO-1, protein expression of COX-2 and HO-1, translocation of NF-κB were assayed by ELISA or Griess method, real-time quantitative PCR, western blot and immunocytochemistry method, respectively. As a result, Corilagin could significantly reduce production of pro-inflammatory cytokines and mediators TNF-α, IL-1β, IL-6, NO (iNOS) and COX-2 on both protein and gene level by blocking NF-κB nuclear translocation. Meanwhile Corilagin could notably promote release of anti-inflammatory factor HO-1 on both protein and gene level, but suppress the release of IL-10. In conclusion, the anti-inflammatory effects of Corilagin are attributed to the suppression of pro-inflammatory cytokines and mediators by blocking NF-κB activation. Corilagin also can promote HO-1 production to induce regression of inflammation but can inhibit IL-10 production like Dexamethasone. Corilagin possesses a potential anti-inflammatory effect by not only abating inflammatory impairment but also promoting regression of inflammation and has a good prospect to be used in many inflammation-related diseases.