| dc.description.abstract | Resumo: A melanina e um pigmento presente na pele com funcao de protecao contra a exposicao a radiacao ultravioleta, controle de temperatura e producao de coloracao adaptativa. Quando a pele humana se expoe a radiacao ultravioleta, cosmeticos inadequados, medicamentos, variacoes hormonais pode haver um acumulo desigual de melanina, originando manchas de hiperpigmentacao. O objetivo deste trabalho foi testar a atividade sobre a melanogenese do extrato hidroalcoolico das folhas da Garcinia gardneriana (EHGG) na linhagem celular de melanoma murino B16F10, pois a planta Garcinia gardneriana (Planchon & Triana) Zappi apresenta perfil fitoquimico de xantonas, triterpenos lupeol e betulina, esteroide ƒÀ-sitosterol, biflavonoides como volkensiflavona, I3-naringenin-II8-eriodictiol(GB-2a), GB-1a, fukugetina. Atraves dos ensaios de viabilidade celular MTT e vermelho neutro foram determinados que as concentracoes de 300 e 1000 ƒÊg/mL diminuiram a viabilidade das celulas B16F10. Por meio de ensaios de conteudo de melanina foram estudadas as taxas de inibicao com o tratamento do EHGG comparando com o acido kojico 500 ƒÊM: por melanogenese espontanea foi obtido uma inibicao nas concentracoes de 3, 10, 30, 100 ƒÊg/mL, respectivamente, 27,92 } 3,46%, 26,63 } 3,92%, 32,41 } 4,05%, 34,13 } 10,99%; por melanogenese induzida por UVB foi conseguido nas concentracoes de extrato utilizadas 10, 30 e 100 ƒÊg/mL uma diminuicao significativa, com uma inibicao de 23,84 } 4,03%, 23,27 } 3,68% e 21,16 } 1,71%, respectivamente; por melanogenese induzida por ƒ¿ . MSH as concentracoes de 100, 30, 10, 3, 1 ƒÊg/mL produziram uma inibicao de 27,47 } 1,61%, 18,48 } 3,51%, 54,31 } 2,50, 65,75 } 4,67%, 60,55 } 3,50%, respectivamente e, em todos os ensaios de conteudo de melanina com o EHGG nao houve reducao da viabilidade celular e o EHGG se mostrou como inibidor da melanogenese. No ensaio da tirosinase celular, a enzima teve sua atividade diminuida em aproximadamente 19% nas concentracoes de 10, 3, 1, 0,3, 0,1 ƒÊg/mL, respectivamente. No ensaio com a tirosinase purificada observou-se uma inibicao de: 34,34 } 2,51%, 32,13 } 4,15%, 11,15 } 2,11%, 18,07 } 1,81%, 22,89 } 1,59%, 19,28 } 1,20%, 18,27 } 3,72% nas concentracoes de 1000, 300, 100, 30, 10, 3, 1 ƒÊg/mL, respectivamente, portanto sua atividade inibitoria esta relacionada com a enzima tirosinase. Quando o biflavonoide GB . 2a foi submetido ao ensaio de conteudo de melanina por melanogenese espontanea, as concentracoes de: 0,1, 1, 10, 100 nM, induziram inibicoes de 44,35 } 5,2%, 48,97 } 5,47%, 52,93 } 1,77%, 58,60 } 3,91%, respectivamente, sem diminuicao da viabilidade das celulas B16F10 e no ensaio da tirosinase purificada nas concentracoes de 1, 10, 100 nM foram demonstradas inibicoes de: 26,82 } 0,81%, 29,93 } 0,65%, 26,62 } 0,55%, respectivamente. A fim de verificar a natureza de inibicao enzimatica sobre a tirosinase, foi realizada a cinetica enzimatica do composto isolado GB . 2a com os substratos L . tirosina e L . DOPA, que inibe a atividade da tirosinase exercendo uma inibicao mista, que para o substrato L . tirosina e tipo nao competitiva e para L . DOPA e tipo acompetitiva. Com esta pesquisa, foi possivel determinar a atividade inibitoria do extrato da planta e do biflavonoide GB . 2a, consequentemente menor biossintese de melanina, portanto com grande potencial de uso em tratamentos dermatologicos e cosmeticos de manchas hipercromicas da pele. | pt_BR |
| dc.description.abstract | Abstract: Melanin is a pigment present in the skin with function of protectingt against exposure to ultraviolet radiation, temperature control and production of adaptive coloration. When human skin is exposed to ultraviolet radiation, inappropriate cosmetics, medicines, hormonal changes can have an uneven accumulation of melanin, resulting in patches of hyperpigmentation. The aim of this study was to test the activity on melanogenesis of hydroalcoholic extract from the leaves of Garcinia gardneriana (EHGG) in B16F10 murine melanoma cell line, as the plant Garcinia gardneriana (Planchon & Triana) Zappi has phytochemistry profile of xanthones, triterpenes lupeol and betulin, steroid â-sitosterol, biflavonoids volkensiflavona, I3- naringenin-II8-eriodictyol (GB-2a), GB-1a, fukugetina. Through the testing of cell viability: MTT and neutral red was determined that concentrations of 300 and 1000 ìg / mL decreased the cell viability of B16F10 cells. Through testing of melanin content were studied rates of inhibition after the treatment of EHGG compared with kojic acid 500 ìM: by spontaneous melanogenesis was obtained inhibition at concentrations of 3, 10, 30, 100 ìg / mL, respectively, 27.92 ± 3.46%, 26.63 ± 3.92%, 32.41 ± 4.05%, 34.13 ± 10.99%; the melanogenesis induced by UVB radiation was achieved at concentrations of extract used 10, 30 and 100 ìg / mL significantly reduction, with an inhibition of 23.84 ± 4.03%, 23.27 ± 3.68% and 21.16 ± 1.71%, respectively; for melanogenesis induced by á - MSH concentrations of 1, 3, 10, 30, 100 ìg / mL induced an inhibition of 60.55 ± 3.50%, 65.75 ± 4.67%, 54.31 ± 2.50%, 18.48 ± 3.51%, 27.41 ± 1.61%, respectively, in all trials of melanin content no reduction cell viability and EHGG proved to inhibit melanogenesis. In the tyrosinase cellular assay, the enzyme reduced its activity about 19% at concentrations of 0.1, 0.3, 1, 3, 10 ìg/mL, respectively. In the purified tyrosinase assay was observed an occurrence of inhibition: 18.27 ± 3.72%, 19.28 ± 1.20%, 22.89 ± 1.59%, 18.07 ± 1.81%, 11.15 ± 2.11%, 32.13% ± 4.15, 34.34 ± 2.51% at concentrations of 1, 3,10, 30, 100, 300, 1000 ìg/mL, respectively, so their activity inhibition is related to the tyrosinase enzyme. When the GB-2a biflavonoid was tested on melanin content by spontaneous melanogenesis, the concentrations of 0.1, 1, 10, 100 nM, induced inhibition of 44.35 ± 5.2%, 48.97 ± 5 47%, 52.93 ± 1.77%, 58.60 ± 3.91%, respectively, without reduction of cell viability and purified tyrosinase assay at concentrations of 1, 10, 100 nM were demonstrated inhibitions: 26.82 ± 0.81%, 29.93 ± 0.65%, 26.62 ± 0.55%, respectively. In order to ascertain the nature of enzyme inhibition on tyrosinase, it performed kinetics analysis of the GB – 2a with L - tyrosine and L – DOPA substrates, which inhibits tyrosinase activity exerting a mixed inhibition, which for the L – tyrosine substrate is a non-competitive type and L - DOPA is uncompetitive type. With this research, we determined the inhibitory activity of plant extract and GB – 2a biflavonoid, hence less melanin biosynthesis therefore with great potential for use in dermatologic and cosmetic skin hyperchromic spots. | pt_BR |
