Dissertações em Neurociências e Biologia Celular (Mestrado) - PPGNBC/ICB
URI Permanente para esta coleçãohttps://repositorio.ufpa.br/handle/2011/2375
O Mestrado Acadêmico pertence ao Programa de Pós-Graduação em Neurociências e Biologia Celular (PPGNBC) do Instituto de Ciências Biológicas (ICB) da Universidade Federal do Pará (UFPA).
Navegar
Navegando Dissertações em Neurociências e Biologia Celular (Mestrado) - PPGNBC/ICB por Assunto "Ácido kójico"
Agora exibindo 1 - 2 de 2
- Resultados por página
- Opções de Ordenação
Item Acesso aberto (Open Access) Estudo da ação imunomodulatória do ácido kójico sobre as células mononucleares da medula óssea de camundongos(Universidade Federal do Pará, 2015-11-03) ALMEIDA, Caroline Martins; SILVA, Edilene Oliveira da; http://lattes.cnpq.br/7410116802190343Bone marrow is soft and sponge-like material found inside bones that contains hematopoietic cells responsible for development and proliferation of peripheral blood cells. The monocytes proliferation generated in the bone marrow and the differentiation of this cells in macrophages plays a key role in the immune response. In this context, the research for drugs that enhance the innate immune response is needed to restore the homeostasis and the immune response. Kojic Acid (KA) is a secondary metabolite synthesized by some species of fungi from Aspergillus genera and has several applications (food additive, cosmetics, antitumor agent and macrophage activator). Thus, the aim of this study is to evaluate the immunomodulatory effects of kojic acid (KA) in the bone marrow cells of mice. These cells were obtained by flushing femurs, and maintained in cultures treated with KA at the concentration of 100 μg/mL for 24-96 hours of culture. It was observed by optical microscopy that KA promoted increased cell adhesion, spreading ability and high number of cytoplasmatic projections and vacuoles in cytoplasm in the mononuclear cells from bone marrow treated with AK. To confirm these results, Akt signaling pathway was analyzed by western blot. KA seems to be able to activate the Akt signaling pathway that have a critical regulatory role in cellular development and differentiation. In addition, we detected by cytometer analysis, increase in the F4/80 and in the CD11b expression, and decrease in CD11c when cells were treated for 96 hours, showing that KA induce the differentiation of bone marrow cells in macrophages, but not in dendritic cells. The Analysis of the microbicidal response revealed that KA also potentiated phagocytosis and increased the production superoxide anion, But not promoted increases of nitric oxide production. Furthermore, no cytotoxic effects were observed in cells treated with KA when compared to the untreated bone marrow cells. Thus, KA acts as an immunomodulatory and is able to induce bone marrow monocyte-macrophage differentiation process.Item Acesso aberto (Open Access) Inibição da atividade da Tirosinase por análogos do ácido Kójico(Universidade Federal do Pará, 2014-11-14) CARDOSO, Erica de Tássia Carvalho; MAUÉS, Luis Antônio Loureiro; http://lattes.cnpq.br/4851018582496177; NASCIMENTO, José Luiz Martins do; http://lattes.cnpq.br/7216249286784978Tyrosinase is an enzyme’s key for melanin biosynthesis. It is a "copper-dependent" enzyme which exhibits three intermediate states: deoxy (Cu1+ -Cu1+), oxi (Cu 2+ - O2 -Cu2+) e met (Cu2+) - Cu2+). This enzyme has bifunctional activity since it can oxidize phenol or catechols in their corresponding o-diphenols. In addition, oxidation of phenols can be described by Michaelis-Menten kinetics. Hyperpigmentation disorders and enzymatic browning of fruit and fungi is associated with tyrosinase.Therefore the research for substances of natural or synthetic origin that could have an effective regulation on the behavior of this enzyme is a key factor of the treatment of such disorders. In this perspective, the present study consisted in analyze the biochemically anti-tyrosinase activity of kojic acid and its analogues derivatives from 4H-pyrones (S-01, S-02, S-03 and S-04) and derivatives from diidropirano [3, 2-b] cromenodionas (S-05, S-06, S-07 and S-08) chemically designed by molecular modeling in LPDF from ICEN UFPa. The kinetics of substances S-02, S-04, S-06, S-07 and S-08 showed competitive inhibition, similar to the pattern of inhibition of kojic acid with Ki values = 145,0 ± 20,0 μM; 64,0 ± 10,0 μM; 4,0 ± 0,0 μM; 6,0 ± 0,0 μM; 9,0 ± 0,0 μM, respectively, and 5,0 ± 0.0 μM for kojic acid, while S-01 had mixed type of inhibition (Ki = 999,0 ± 150,0 μM). Since the S-03 and S-05 substances showed no inhibitory activity. The substances tested demonstrated a high degree of safety both in the integrity of the erythrocyte membrane in the hemolysis test as in the test with MTT viability in cultures of MRC5 fibroblasts, culture of nerve cells from chicken embryo retina and B16F10 melanoma. Thus, it was demonstrated that S-02, S-04, S-06, S-07 and S-08 substances have potent activity as inhibitors of tyrosinase and may be candidates for the treatment of pigmentation disorders.