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 50μg/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.

Jeju seaweeds suppress lipopolysaccharide-stimulated proinflammatory response in RAW 264.7 murine macrophages

Objective:To investigate the anti-inflammatory effects of Jeju seaweeds on macrophage RAW264.7 cells under lipopolysaccharide(LPS)stimulation.Methods:Ethyl acetate fractions were prepared from five different types of Jeju seaweeds,Dictyopteris divaricata(D.divaricata),Dictyopteris prolifera(D.prolifefa),Prioutis cornea(P.comea,Grateloupia laceolata(G,lanceolate,and Cralcloupia filicina(G.filicina)They were screened for inhibitory effects on proinflammatory mediators and cytokines such as nitric oxide(NO),prostaglandin E,,tumor necrosis factor-a(TNF-a),and interleukin-6(11.-6).Results:Our results revealed that D.divaricata,D.prolifera,P.cornea,G.lanceolata,and G.filicina potently inhibited I.PS-stimulaled NO production(IC_(50),values were 18.0,38.36,38.43,32.81 and 37.14μg/mL,respectively).Consistent with these findings,D.divtricata,D.prolifera,P.cornea,and G.fdicina also reduced the IPS-induced and prostaglandin E,production in a concentration-dependent manner.Expectedly,they suppressed the expression of inducible NO synthase and cyclooxygenase-2 at the protein level in a dose-dependent manner in the RAW264.7 cells,as detennined by western blotting.In addition,the levels of TNF-a and IL-6,released into the medium,were also reduced by D.divaricata,D.prolifera,P.cornea,G,lanceolata,and G.fdicina in a dose-dependent manner(IC_(50)values for TNF-a were 16.11,28.21,84.27,45.52 and74.75μg/mL,respectively;IC_(50),values for IL-6 were 37.35,80.08,103.28,62.53 and 84.28μg/mL,respectively).The total phlorotannin content was measured by the Folin-Ciocalteu method and expressed as phloroglucinol equivalents.The content was 92.0μg/mg for D.divaricata,151.8μg/mg for D.prolifera,57.2μg/mg for P.cornea,53.0 pg/mg for G.lanceolata,and 40.2μg/mg for G.fdicina.Conclusions:Thus,these findings suggest that Jeju seaweed extracts have potential therapeutic applications for inflammatory responses.