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During our on-going screening program designed to isolate natural compounds from marine environments, we isolated isoketochabrolic acid (IKCA) from Sargassum micracanthum, an important brown algae distributed in Jeju Island, Korea. Furthermore, we evaluated the inhibitory effects of IKCA on nitric oxide (NO) production in lipopolysaccharide (LPS)-triggered macrophages. IKCA strongly inhibited NO production, with an IC50 value of 58.31 µM. Subsequent studies demonstrated that IKCA potently and concentration-dependently reduced prostaglandin E2 (PGE2), tumor necrosis factor-alpha (TNF-α), interleukin (IL)-1ß, and IL-6 cytokine production. In conclusion, to the best of our knowledge, this is the first study to show that IKCA isolated from S. micracanthum has a potent anti-inflammatory activity. Therefore, IKCA might be useful as an anti-inflammatory health supplement or functional cosmetics. [ABSTRACT FROM AUTHOR]

Despite its beneficial role in host defense mechanisms, excessive nitric oxide (NO) production by activated macrophages has been implicated in several inflammatory diseases. To clarify the mechanisms of the anti-inflammatory activities of Sargassum micracanthum, we evaluated whether extracts of S. micracanthum could modulate the production of NO by activated macrophages. S. micracanthum were extracted with 80% EtOH. The extract was then successively partitioned with hexane, CH2Cl2, EtOAc, BuOH, and water. The results indicate that the hexane and CH2Cl2 fractions of S. micracanthum extract were effective inhibitors of LPS-induced NO and prostaglandin E2 (PGE2) production in RAW 264.7 cells. The inhibitory effects of the hexane and CH2Cl2 fractions of S. micracanthum were accompanied by dosedependent decreases in the production of iNOS and COX-2 proteins and iNOS and COX-2mRNA expression. To test the inhibitory effects of S. micracanthum fractions on other cytokines, we also performed ELISA and RT-PCR assays for TNF-α, IL-1β, and IL-6 in LPSstimulated RAW 264.7 macrophage cells. In these assays, the hexane and CH2Cl2 fractions of S. micracanthum produced dose-dependent decreases in the production and mRNA expression of TNF-α, IL-1β, and IL-6. To test the potential application of S. micracanthum extract as a cosmetic material, we also performed MTT assays on human dermal fibroblast cells, as well asprimary skin irritation tests. In these assays, S. micracanthum extracts did not induce any adverse reactions. Based on these results, we suggest that S. micracanthum extracts may be considered potential anti-inflammatory candidates for topical application. [ABSTRACT FROM AUTHOR]

Nitric oxide (NO) is a crucial molecule in inflammatory diseases and is synthesized from L-arginine by a specific enzyme, NO synthase (NOS). The expression of inducible NOS (iNOS) is activated in macrophages by various stimuli, such as lipopolysaccharide (LPS), a wall component of gram-negative bacteria. LPS binds to toll-like receptor 4 (TLR4) on the macrophage surface and activates several downstream signaling pathways, including mitogen-activated protein kinase (MAPK) and nuclear factor (NF)-κB pathways. This study investigated whether sargaquinoic acid isolated from Sargassum siliquastrum might have anti-inflammatory activity and interfere with NO production in macrophages by disrupting LPS-induced signaling. This study was conducted in vitro using RAW264.7 murine macrophages. LPS-stimulated cells were treated with sargaquinoic acid, and the effects on NO production, iNOS expression, and involvement of the NF-κB signaling pathway were investigated by Griess assay, western blotting, and confocal microscopy. The results demonstrated that sargaquinoic acid inhibited the production of NO and the expression of the iNOS protein in LPS-stimulated RAW264.7 macrophages. Moreover, sargaquinoic acid inhibited the degradation of inhibitory-κB protein (IκB)-α and the nuclear translocation of NF-κB, a key transcription factor for the regulation of iNOS expression. Also, sargaquinoic acid influenced the phosphorylation of JNK1/2 MAPK, except ERK1/2 and p38 MAPKs, stimulated by LPS. These results suggest that sargaquinoic acid specifically prevents NO production in macrophages via the blockade of NF-κB activation and may thus have therapeutic applications in various inflammatory diseases. [ABSTRACT FROM AUTHOR]

Since acne vulgaris is the combined result of a bacterial infection and the inflammatory response to that infection, we examined whether Abies koreana essential oil (AKE) possessed anti-inflammatory and antibacterial activities against skin pathogens. In this study, AKE showed excellent antibacterial activities against drug-susceptible and -resistant Propionibacterium acnes and Staphylococcus epidermidis, which are acne-causing bacteria. In addition, AKE reduced the LPS-induced secretion of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), IL-6, NO and PGE2 in RAW 264.7 cells, indicating that it has anti-inflammatory effects. Therefore, we suggest that AKE may be an attractive candidate for promoting skin health. [ABSTRACT FROM AUTHOR]

Periodontal disease, a chronic disease caused by bacterial infection, eventually progresses to severe inflammation and bone loss. Regulating excessive inflammation of inflamed periodontal tissues is critical in treating periodontal diseases. The periodontal ligament (PDL) is primarily a connective tissue attachment between the root and alveolar bone. PDL fibroblasts (PDLFs) produce pro-inflammatory cytokines in response to bacterial infection, which could further adversely affect the tissue and cause bone loss. In this study, we determined the ability of Litsea japonica leaf extract (LJLE) to inhibit pro-inflammatory cytokine production in PDLFs in response to various stimulants. First, we found that LJLE treatment reduced lipopolysaccharide (LPS)-induced pro-inflammatory cytokine (interleukin-6 and interleukin-8) mRNA and protein expression in PDLFs without cytotoxicity. Next, we observed the anti-inflammatory effect of LJLE in PDLFs after infection with various oral bacteria, including Fusobacterium nucleatum, Porphyromonas gingivalis, Treponema denticola, and Tannerella forsythia. These anti-inflammatory effects of LJLE were dose-dependent, and the extract was effective following both pretreatment and posttreatment. Moreover, we found that LJLE suppressed the effect of interleukin-1 beta-induced pro-inflammatory cytokine production in PDLFs. Taken together, these results indicate that LJLE has anti-inflammatory activity that could be exploited to prevent and treat human periodontitis by controlling inflammation. [ABSTRACT FROM AUTHOR]