Atividade biológica de extratos acetato de etila, etanólico e aquoso de timbó (Lonchocarpus floribundus) sobre carrapato bovino

Os extratos acetato de etila, etanólico e aquoso de raízes de Lonchocarpus floribundus foram utilizados, a fim de avaliar a atividade biológica sobre carrapato bovino. Carrapatos adultos foram coletados em bovinos infestados artificialmente, separados em grupos de dez indivíduos, pesados e imersos, separadamente, nos extratos de raízes de L. Floribundus, nas concentrações de 5, 25, 50, 75 e 100 mg mL-1. Para a avaliação em larvas, foram utilizados indivíduos de 14 a 21 dias, os quais foram imersos nos extratos nas concentrações de 1, 5, 10, 15 e 20 mg mL-1. Após o tratamento, cada grupo foi colocado em placa de Petri e incubado a 27 ± 1 ºC e umidade relativa de 80 ± 5%. Os extratos avaliados não foram eficazes para induzir, acima de 50%, a mortalidade de fêmeas ingurgitadas. Os extratos acetato de etila e etanólico induziram 100% de mortalidade de larvas. Entretanto, quanto aos valores de concentração letal mediana (CL50), o extrato etanólico (CL50 = 2,1 mg mL-1) foi mais tóxico que o extrato acetato de etila (CL50 = 4,1 mg mL-1). O extrato etanólico estimou concentração inibitória mediana (CI50) de 3,0 mg mL-1 e foi mais tóxico que os demais extratos quanto a este parâmetro de avaliação. Entre os três extratos avaliados, os extratos acetato de etila e etanólico apresentaram os melhores resultados quanto ao controle de reprodução de R. (B.) microplus, atingindo 100% na concentração de 5 mg mL-1. Os extratos de raízes de L. Floribundus apresentaram atividade biológica sobre carrapato bovino

Óleo de citronela no controle do carrapato de bovinos Citronella oil on the control of catle ticks

O objetivo deste estudo foi avaliar o efeito in vivo e in vitro do óleo de citronela (Cymbopogon nardus (L.) Rendle) no carrapato de bovinos (Boophilus microplus). O óleo foi obtido de folhas frescas pelo processo de destilação e o rendimento foi de 0,7%. Para as experimentações in vitro foram usadas sete (0; 0,5; 1,0; 10,0; 25,0; 50,0; 100,0%) e nove (0,1; 0,25; 0,5; 1,0; 2,0; 10,0; 25,0; 50,0; 100%) concentrações de óleo de citronela, sendo testadas em fêmeas ingurgitadas. A eficácia observada foi de 0; 44,2; 92,1; 85,6; 87,8; 87,0; 88,9 e de 0,7; 2,8; 51,6; 79,3; 81,0; 87,1; 86,7; 89,5%, respectivamente. Os resultados sugerem que o óleo de citronela pode ser usado no controle do carrapato bovino.<br>This research was aimed at evaluating in vitro and in vivo effects of citronella (Cymbopogon nardus (L.) Rendle) oil on catle ticks. The volatile oil was obtained from de fresh leaves of citronella grass by steam destilation and the yelds was 0.7%. Seven (0; 0.5; 1.0; 10.0; 25.0; 50.0; 100.0%) and nine (0.1; 0.25; 0.5; 1.0; 2.0; 10.0; 25.0; 50.0; 100.0%) concentrations of citonella oil were used on in vitro trials with engorged female ticks. The efficacy control ticks was 0; 44.2; 92.1; 85.6; 87.8; 87.0; 88.9 and 0; 0.7; 2.8; 51.6; 79.3; 81.0; 87.1; 86.7 89.5 %, respectively. These sugest that the citronella oil can be practical used for controlling of catle ticks

Vitamin D3 Induces Ido+ Tolerogenic Dcs And Enhances Treg, Reducing The Severity Of Eae

Background: A growing body of evidence supports the hypothesis that vitamin D is an important environmental factor in the etiology of T-cell-mediated autoimmune diseases such as multiple sclerosis (MS). Aim: The purpose of this study was exploring the mechanisms underlying the beneficial effect of vitamin D3 in encephalomyelitis (EAE). Methods: We treated monophasic experimental autoimmune EAE, induced in Lewis rat, with vitamin D3 and adoptively transfer tolerogenic bone marrow-derived DCs generated in the presence of vitamin D3. Results: This study provides evidence that the in vivo administration of vitamin D3, as well as the adoptive transfer of vitamin D3-induced IDO+ immature/tolerogenic dendritic cells, leads to a significant increase in the percentage of CD4+CD25+Foxp3+ regulatory T cells in the lymph nodes in a rat model of MS, experimental autoimmune EAE. Concomitant with the increase in this cell population, there is a significant decrease in the number of autoreactive T cells in the central nervous system. Bone marrow-derived DCs cultivated in the presence of vitamin D3 present a tolerogenic profile with high IL-10, TNFα, and IDO expression and decreased MHC-II and CD80 expression. The adoptive transfer of IDO + DCs induces a significant increase in the percentage of CD4+CD25+Foxp3+ T cells in the lymph nodes, comparable with vitamin D3 treatment. Conclusion: These mechanisms contribute actively to the generation of a microenvironment in the lymph nodes that suppresses the activation of encephalitogenic T cells, resulting in the downregulation of the inflammatory response in the central nervous system. © 2013 Blackwell Publishing Ltd.194269277Hafler, D.A., Slavik, J.M., Anderson, D.E., O'Connor, K.C., De Jager, P., Baecher-Allan, C., Multiple sclerosis (2005) Immunol Rev, 204, pp. 208-231van der Mei, I.A., Ponsonby, A.L., Blizzard, L., Dwyer, T., Regional variation in multiple sclerosis prevalence in Australia and its association with ambient ultraviolet radiation (2001) Neuroepidemiology, 20, pp. 168-174Wallin, M.T., Page, W.F., Kurtzke, J.F., Multiple sclerosis in US veterans of the Vietnam era and later military service: Race, sex, and geography (2004) Ann Neurol, 55, pp. 65-71Cantorna, M.T., Hayes, C.E., DeLuca, H.F., 1,25-Dihydroxyvitamin D3 reversibly blocks the progression of relapsing encephalomyelitis, a model of multiple sclerosis (1996) Proc Natl Acad Sci U S A, 93, pp. 7861-7864Spach, K.M., Hayes, C.E., Vitamin D3 confers protection from autoimmune encephalomyelitis only in female mice (2005) J Immunol, 175, pp. 4119-4126Becklund, B.R., Hansen Jr, D.W., Deluca, H.F., Enhancement of 1,25-dihydroxyvitamin D3-mediated suppression of experimental autoimmune encephalomyelitis by calcitonin (2009) Proc Natl Acad Sci U S A, 106, pp. 5276-5281Santos, L.M., al-Sabbagh, A., Londono, A., Weiner, H.L., Oral tolerance to myelin basic protein induces regulatory TGF-beta-secreting T cells in Peyer's patches of SJL mice (1994) Cell Immunol, 157, pp. 439-447Hou, S.W., Liu, C.Y., Li, Y.H., Fasudil ameliorates disease progression in experimental autoimmune encephalomyelitis, acting possibly through antiinflammatory effect (2012) CNS Neurosci Ther, 18, pp. 909-917Spach, K.M., Nashold, F.E., Dittel, B.N., Hayes, C.E., IL-10 signaling is essential for 1,25-dihydroxyvitamin D3-mediated inhibition of experimental autoimmune encephalomyelitis (2006) J Immunol, 177, pp. 6030-6037Bettelli, E., Carrier, Y., Gao, W., Reciprocal developmental pathways for the generation of pathogenic effector TH17 and regulatory T cells (2006) Nature, 441, pp. 235-238Langrish, C.L., Chen, Y., Blumenschein, W.M., IL-23 drives a pathogenic T cell population that induces autoimmune inflammation (2005) J Exp Med, 201, pp. 233-240Park, H., Li, Z., Yang, X.O., A distinct lineage of CD4 T cells regulates tissue inflammation by producing interleukin 17 (2005) Nat Immunol, 6, pp. 1133-1141O'Connor, R.A., Prendergast, C.T., Sabatos, C.A., Cutting edge: Th1 cells facilitate the entry of Th17 cells to the central nervous system during experimental autoimmune encephalomyelitis (2008) J Immunol, 181, pp. 3750-3754Muthian, G., Raikwar, H.P., Rajasingh, J., Bright, J.J., 1,25 Dihydroxyvitamin-D3 modulates JAK-STAT pathway in IL-12/IFNgamma axis leading to Th1 response in experimental allergic encephalomyelitis (2006) J Neurosci Res, 83, pp. 1299-1309Tang, J., Zhou, R., Luger, D., Calcitriol suppresses antiretinal autoimmunity through inhibitory effects on the Th17 effector response (2009) J Immunol, 182, pp. 4624-4632Adorini, L., Penna, G., Dendritic cell tolerogenicity: A key mechanism in immunomodulation by vitamin D receptor agonists (2009) Hum Immunol, 70, pp. 345-352Mora, J.R., Iwata, M., von Andrian, U.H., Vitamin effects on the immune system: Vitamins A and D take centre stage (2008) Nat Rev Immunol, 8, pp. 685-698Hewison, M., Freeman, L., Hughes, S.V., Differential regulation of vitamin D receptor and its ligand in human monocyte-derived dendritic cells (2003) J Immunol, 170, pp. 5382-5390Piemonti, L., Monti, P., Sironi, M., Vitamin D3 affects differentiation, maturation, and function of human monocyte-derived dendritic cells (2000) J Immunol, 164, pp. 4443-4451Szeles, L., Keresztes, G., Torocsik, D., 1,25-dihydroxyvitamin D3 is an autonomous regulator of the transcriptional changes leading to a tolerogenic dendritic cell phenotype (2009) J Immunol, 182, pp. 2074-2083Correale, J., Ysrraelit, M.C., Gaitan, M.I., Vitamin D-mediated immune regulation in multiple sclerosis (2011) J Neurol Sci, 311, pp. 23-31Tang, Q., Bluestone, J.A., The Foxp3 +  regulatory T cell: A jack of all trades, master of regulation (2008) Nat Immunol, 9, pp. 239-244Awasthi, A., Carrier, Y., Peron, J.P., A dominant function for interleukin 27 in generating interleukin 10-producing anti-inflammatory T cells (2007) Nat Immunol, 8, pp. 1380-1389Carrier, Y., Yuan, J., Kuchroo, V.K., Weiner, H.L., Th3 cells in peripheral tolerance. II. TGF-beta-transgenic Th3 cells rescue IL-2-deficient mice from autoimmunity (2007) J Immunol, 178, pp. 172-178Sakaguchi, S., Ono, M., Setoguchi, R., Foxp3 +  CD25 +  CD4 +  natural regulatory T cells in dominant self-tolerance and autoimmune disease (2006) Immunol Rev, 212, pp. 8-27Anderton, S.M., Liblau, R.S., Regulatory T cells in the control of inflammatory demyelinating diseases of the central nervous system (2008) Curr Opin Neurol, 21, pp. 248-254O'Connor, R.A., Anderton, S.M., Foxp3 +  regulatory T cells in the control of experimental CNS autoimmune disease (2008) J Neuroimmunol, 193, pp. 1-11Awasthi, A., Murugaiyan, G., Kuchroo, V.K., Interplay between effector Th17 and regulatory T cells (2008) J Clin Immunol, 28, pp. 660-670Barrat, F.J., Cua, D.J., Boonstra, A., In vitro generation of interleukin 10-producing regulatory CD4(+) T cells is induced by immunosuppressive drugs and inhibited by T helper type 1 (Th1)- and Th2-inducing cytokines (2002) J Exp Med, 195, pp. 603-616Ureta, G., Osorio, F., Morales, J., Rosemblatt, M., Bono, M.R., Fierro, J.A., Generation of dendritic cells with regulatory properties (2007) Transplant Proc, 39, pp. 633-637Penna, G., Roncari, A., Amuchastegui, S., Expression of the inhibitory receptor ILT3 on dendritic cells is dispensable for induction of CD4(+)Foxp3(+) regulatory T cells by 1,25-dihydroxyvitamin D-3 (2005) Blood, 106, pp. 3490-3497Farias, A.S., Martins-de-Souza, D., Guimaraes, L., Proteome analysis of spinal cord during the clinical course of monophasic experimental autoimmune encephalomyelitis (2012) Proteomics, 12, pp. 2656-2662Farias, A.S., Talaisys, R.L., Blanco, Y.C., Regulatory T cell induction during Plasmodium chabaudi infection modifies the clinical course of experimental autoimmune encephalomyelitis (2011) PLoS ONE, 6, pp. e17849Ramsdell, F., Foxp3 and natural regulatory T cells: Key to a cell lineage? (2003) Immunity, 19, pp. 165-168Sucher, R., Fischler, K., Oberhuber, R., IDO and regulatory T cell support are critical for cytotoxic T lymphocyte-associated Ag-4 Ig-mediated long-term solid organ allograft survival (2012) J Immunol, 188, pp. 37-46O'Sullivan, B.J., Pai, S., Street, S., Immunotherapy with costimulatory dendritic cells to control autoimmune inflammation (2011) J Immunol, 187, pp. 4018-4030Sun, Y., Chin, Y.E., Weisiger, E., Cutting edge: Negative regulation of dendritic cells through acetylation of the nonhistone protein STAT-3 (2009) J Immunol, 182, pp. 5899-5903Enioutina, E.Y., Bareyan, D., Daynes, R.A., Vitamin D3-mediated alterations to myeloid dendritic cell trafficking in vivo expand the scope of their antigen presenting properties (2007) Vaccine, 25, pp. 1236-1249Pallotta, M.T., Orabona, C., Volpi, C., Indoleamine 2,3-dioxygenase is a signaling protein in long-term tolerance by dendritic cells (2011) Nat Immunol, 12, pp. 870-878Steinbrink, K., Wolfl, M., Jonuleit, H., Knop, J., Enk, A.H., Induction of tolerance by IL-10-treated dendritic cells (1997) J Immunol, 159, pp. 4772-4780Chen, W., IDO: More than an enzyme (2011) Nat Immunol, 12, pp. 809-811Smolders, J., Peelen, E., Thewissen, M., The relevance of vitamin D receptor gene polymorphisms for vitamin D research in multiple sclerosis (2009) Autoimmun Rev, 8, pp. 621-62