Anti-inflammatory effect of Pyrrosia lingua extract on Raw 264.7 macrophages

To test the potential use of the fern Pyrrosia lingua as an anti-inflammatory functional material, we examined the effects of P. lingua ethanol extract (PLE) on RAW 264.7 macrophages treated with the pro-inflammatory molecule lipopolysaccharide (LPS). Notably, up to 100 μg/mL PLE did not result in any discernable inhibition of cellular metabolic activity or cytotoxicity in the macrophages. However, supplementing LPS-treated RAW 264.7 macrophages with PLE significantly suppressed various pro-inflammatory responses in a dose-dependent manner, including i) phosphorylation of nuclear factor-kappa B (NF-κB) subunit p65; ii) accumulation of inducible nitric oxide synthase and cyclooxygenase-2; iii) expression of pro-inflammatory mediators, including prostaglandin E synthase 2 and nitrite; and iv) expression of pro-inflammatory biomarker genes, including interleukin 1 beta, interleukin 6, tumor necrosis factor-alpha, and monocyte chemoattractant protein-1. Taken together, our results indicate that PLE regulates NF-κB signaling and inhibits cytokine production. Therefore, the use of domestic biological resources like could be increased P. lingua as a novel functional material.