Purpose Chronic inflammation is a key contributor to the development of various metabolic and cardiovascular diseases, underscoring the importance of identifying effective anti-inflammatory agents. Natural products are gaining increasing attention as potential sources of bioactive compounds with therapeutic value. Gloiopeltis tenax (G. tenax) , an edible red alga widely consumed in East Asia, exhibits antioxidant and antimicrobial activities; however, its anti-inflammatory effects remain poorly understood. In this study, we investigated the anti-inflammatory potential of an ethanolic extract of G. tenax in lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages. Methods The effects of G. tenax extract on the production of inflammatory mediators and major signaling pathways were investigated in LPS-stimulated RAW264.7 macrophages. Results Exposure to G. tenax extract markedly attenuated LPS-stimulated nitric oxide production and the release of pro-inflammatory cytokines, such as tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6), accompanied by downregulation of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) expression, with no detectable cytotoxicity. Moreover, the extract attenuated nuclear factor-κB (NF-κB) pathway activation by suppressing inhibitor of κB (IκB) phosphorylation and attenuation of NF-κB pathway activation. In addition, phosphorylation of mitogen-activated protein kinase (MAPK) signaling components was markedly attenuated in the cells treated with extract. Conclusion Collectively, these results demonstrate that G. tenax extract exhibits anti-inflammatory activity in macrophages by suppressing inflammatory mediator production, including iNOS and COX-2 expression, and by regulating the NF-κB and MAPK signaling pathways, highlighting its promise as a functional food ingredient or a natural anti-inflammatory agent.
Lee et al. (Mon,) studied this question.