Inhibitory Effect of Ulva fasciata and Desmarestia viridis on the Production of Nitric Oxide, Prostaglandin E2, and Pro-inflammatory Cytokines in RAW 264.7 Cells.

Nitric oxide (NO) and prostaglandin (PG)E2, known inflammatory mediators, are critically involved in the pathogenesis of a large number of human inflammatory diseases. Therefore, a search of inducible nitric oxide synthases (iNOS) and cyclooxygenase 2 (COX-2) selective inhibitors is a useful strategy to find functional substances to alleviate inflammatory disease. In our search for anti-inflammatory ingredients, we found that extracts of Ulva fasciata (UFE) and Desmarestia viridis (DVE) inhibit the generation of NO and PGE2 in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophage cells. U. fasciata and D. viridis were extracted with 80% ethanol and then partitioned successively with ethyl acetate. The ethyl acetate fractions are effective dose-dependent inhibitors of LPS-induced NO and PGE2 synthesis in RAW 264.7 cells. To test the inhibitory effects of UFE and DVE on pro-inflammatory cytokines, we performed ELISA assays for tumor necrosis factor (TNF)-α, IL (interleukin)-1β, and IL(interleukin)-6 in LPS-stimulated RAW 264.7 macrophage cells. In these assays, the UFE and DVE showed a dose-dependent decrease in the production of TNF-α, IL-1β, and IL-6. As a preliminary study of the anti-inflammatory mechanism, we determined, using the Western blot analysis, whether or not UFE and DVE inhibit the degradation of I-kappa-B-alpha (IκB-α). Our results indicate that UFE and DVE indeed prevent the degradation of IκB-α, in a dose-dependent manner. Based on these results, we suggest that extracts of U. fasciata and D. viridis be considered candidates for anti-inflammatory agents for human use.

Down-regulation of tyrosinase, TRP-1, TRP-2 and MITF expressions by citrus press-cakes in murine B16 F10 melanoma

Objective: To investigate the suitability of citrus-press cakes, by-products of the juice industry as a source for the whitening agents for cosmetic industry. Methods:Ethylacetate extracts of citrus-press cakes (CCE) were examined for their anti-melanogenic potentials in terms of the inhibition of melanin production and mechanisim of melanogenesis by using Western Blot analysis with tyrosinese, tyrosinase-related protein-1 (TRP-1), TRP2, and microphthalmia-associated transcription factor (MITF) proteins. To apply the topical agents, citrus-press cakes was investigated the safety in human skin cell line. Finally flavonoid analysis of CCE was also determined by HPLC analysis. Results: Results indicated that CCE were shown to down-regulate melanin content in a dose-dependent pattern. The CCE inhibited tyrosinase, TRP-2, and MITF expressions in a dose-dependent manner. To test the applicability of CCE to human skin, we used MTT assay to assess the cytotoxic effects of CCE on human keratinocyte HaCaT cells. The CCE exhibited low cytotoxicity at 50 μg/mL. Characterization of the citrus-press cakes for flavonoid contents using HPLC showed varied quantity of rutin, narirutin, and hesperidin. Conclusions:Considering the anti-melanogenic activity and human safety, CCE is considered as a potential anti-melanogenic agent and may be effective for topical application for treating hyperpigmentation disorders.