Polyopes affinis Suppressed IFN-γ- and TNF-α-Induced Inflammation in Human Keratinocytes via Down-Regulation of the NF-κB and STAT1 Pathways.

Polyopes affinis is a red algal species commonly found on the South coast and near Jeju Island, Korea. This study aimed to determine whether P. affinis extracts can inhibit the pathogenesis of T-helper-2 (Th2)-mediated inflammation in a human keratinocyte cell line of atopic dermatitis (AD). Cells were incubated with 10 ng/mL of interferon gamma (IFN-γ) and 10 ng/mL of tumor necrosis factor-alpha (TNF-α) at various concentrations of PAB (10, 30, and 60 µg/mL) and PAA (100, 500, and 1000 µg/mL) extracts. A gene-ontology (GO)-enrichment analysis revealed that PAB significantly enriched the genes associated with biological processes such as cell adhesion, immune response, inflammation, and chemokine-mediated pathways. PAB suppressed the expression of the secretory proteins and mRNAs that are associated with the thymus and the production of activation-regulated chemokines (TARC/CCL17) and macrophage-derived chemokines (MDC/CCL22). The effect of the extract on mitogen-activated protein kinases (MAPKs) was related to its inhibition of TARC/CCL17 and MDC/CCL22 production by blocking NF-κB and STAT1 activation. These results suggest that seaweed extract may improve AD by regulating pro-inflammatory chemokines. In conclusion, we first confirmed the existence of phloroglucinol, a polyphenol formed from a precursor called phlorotannin, which is present in PAB, and this result proved the possibility of PAB being used as a treatment for AD.

Pyropia yezoensis Extract Suppresses IFN-Gamma- and TNF-Alpha-Induced Proinflammatory Chemokine Production in HaCaT Cells via the Down-Regulation of NF-κB.

Pyropia yezoensis, a red alga, is popular and harvested a lot in East Asia and is famous for its medicinal properties attributable to its bioactive compounds including amino acids (porphyra-334 and shinorine, etc.), polysaccharides, phytosterols, and pigments, but its anti-inflammatory effect and mechanism of anti-atopic dermatitis (AD) have not been elucidated. In this study, we investigate the anti-AD effect of P. yezoensis extract (PYE) on mRNA and protein levels of the pro-inflammatory chemokines, thymus, and activation-regulated chemokine (TARC/CCL17) and macrophage-derived chemokine (MDC/CCL22), in human HaCaT keratinocyte cells treated to interferon (IFN)-γ or tumor necrosis factor (TNF)-α (10 ng/mL each). The effect of the PYE on extracellular signal-regulated kinase (ERK) and other mitogen-activated protein kinases (MAPKs) was related to its suppression of TARC and MDC production by blocking NF-κB activation in HaCaT cells. Furthermore, astaxanthin and xanthophyll from P. yezoensis were identified as anti-AD candidate compounds. These results suggest that the PYE may improve AD and contained two carotenoids by regulating pro-inflammatory chemokines.