Anti-inflammatory activity of lignin fraction from Sasa senanensis Rehder

Objectives: Sasa senanensis Rehder extract (SE) has been reported to show anti-septic, membrane stabilizing, anti-inflammatory and radical scavenging activity. We have recently reported that SE showed a bacteriostatic effect on Fusobacterium nucleatum and Prevotella intermedia, but almost completely eliminated the volatile sulfur compounds produced by these bacteria. We investigated here whether SE inhibits the production of nitric oxide (NO) and prostaglandin E₂ (PGE₂) by lipopolysaccharide (LPS)-activated mouse macrophage-like cells RAW264.7. Methods: Lignin carbohydrate complex was prepared by acid precipitation of SE by lowering the pH to 5 with acetic acid, followed by dialysis against water and lyophilization. NO was determined by Griess method, and PGE2 by EIA. iNOS and COX-2 expression at protein and mRNA levels were determined by Western blot analysis and RT-PCR method, respectively. NO, produced by NOC-7 was determined by ESR spectroscopy. Results: SE dose-dependently inhibited the NO and PGE₂ production by activated macrophages, and this was due to both the inhibition of iNOS and COX-2 expression and the scavenging of NO radical. Lignin fraction inhibited the NO production more efficiently than SE. Solvent fractionation revealed that chlorophyllin in SE was mostly concentrated into water layer, but not in organic solvent layers. Exogenous chlorophyllin inhibited the NO production to the greatest extent. Conclusion: Lignin fraction possible conjugated with chrolophyllin may be the active principle for the anti-inflammatory activity of SE. The possible anti-inflammatory activity of SE and its lignin fraction against gingivitis should be pursued.