BRUNO LUIZ SOARES CAMPOS
Projetos de Pesquisa
Unidades Organizacionais
LIM/50 - Laboratório de Patologia das Moléstias Infecciosas, Hospital das Clínicas, Faculdade de Medicina
4 resultados
Resultados de Busca
Agora exibindo 1 - 4 de 4
- The Effect of Ursolic Acid on Leishmania (Leishmania) amazonensis Is Related to Programed Cell Death and Presents Therapeutic Potential in Experimental Cutaneous Leishmaniasis(2015) YAMAMOTO, Eduardo S.; CAMPOS, Bruno L. S.; JESUS, Jessica A.; LAURENTI, Marcia D.; RIBEIRO, Susan P.; KALLAS, Esper G.; RAFAEL-FERNANDES, Mariana; SANTOS-GOMES, Gabriela; SILVA, Marcelo S.; SESSA, Deborah P.; LAGO, Joao H. G.; LEVY, Debora; PASSERO, Luiz F. D.Among neglected tropical diseases, leishmaniasis is one of the most important ones, affecting more than 12 million people worldwide. The available treatments are not well tolerated, and present diverse side effects, justifying the search for new therapeutic compounds. In the present study, the activity of ursolic acid (UA) and oleanolic acid (OA) were assayed in experimental cutaneous leishmaniasis (in vitro and in vivo). Promastigote forms of L. amazonensis were incubated with OA and UA for 24h, and effective concentration 50% (EC50) was estimated. Ultraestructural alterations in Leishmania amazonensis promastigotes after UA treatment were evaluated by transmission electron microscopy, and the possible mode of action was assayed through Annexin V and propidium iodide staining, caspase 3/7 activity, DNA fragmentation and transmembrane mitochondrial potential. The UA potential was evaluated in intracellular amastigotes, and its therapeutic potential was evaluated in L. amazonensis infected BALB/c mice. UA eliminated L. amazonensis promastigotes with an EC50 of 6.4 mu g/mL, comparable with miltefosine, while OA presented only a marginal effect on promastigote forms at 100 mu g/mL. The possible mechanism by which promastigotes were eliminated by UA was programmed cell death, independent of caspase 3/7, but it was highly dependent on mitochondria activity. UA was not toxic for peritoneal macrophages from BALB/c mice, and it was able to eliminate intracellular amastigotes, associated with nitric oxide (NO) production. OA did not eliminate amastigotes nor trigger NO. L. amazonensis infected BALB/c mice submitted to UA treatment presented lesser lesion size and parasitism compared to control. This study showed, for the first time, that UA eliminate promastigote forms through a mechanism associated with programed cell death, and importantly, was effective in vivo. Therefore, UA can be considered an interesting candidate for future tests as a prototype drug for the treatment of cutaneous leishmaniasis.
- Analysis of iron superoxide dismutase-encoding DNA vaccine on the evolution of the Leishmania amazonensis experimental infection(2015) CAMPOS, B. L. S.; SILVA, T. N.; RIBEIRO, S. P.; CARVALHO, K. I. L.; KALLAS, E. G.; LAURENTI, M. D.; PASSERO, L. F. D.The present work aimed to evaluate the immunogenicity of Leishmania amazonensis iron superoxide dismutase (SOD) -encoding DNA experimental vaccine and the protective properties of this DNA vaccine during infection. The SOD gene was subcloned into the pVAX1 plasmid, and it was used to immunize BALB/c mice. Twenty-one days after the last immunization, mice were sacrificed (immunogenicity studies) or subcutaneously challenged with L. amazonensis (studies of protection), and alterations in cellular and humoral immune responses were evaluated, as well as the course of infection. Mice only immunized with pVAX1-SOD presented increased frequencies of CD4(+) IFN-gamma(+), CD8(+) IFN- gamma(+) and CD8(+) IL-4(+) lymphocytes; moreover, high levels of IgG2a were detected. After challenge, mice that were immunized with pVAX1-SOD had increased frequencies of the CD4(+) IL- 4(+), CD8(+) IFN-gamma(+) and CD8(+) IL-4(+) T lymphocytes. In addition, the lymph node cells produced high amounts of IFN-gamma and IL-4 cytokines. Increased IgG2a was also detected. The pattern of immunity induced by pVAX1-SOD partially protected the BALB/c mice from a challenge with L. amazonensis, as the animals presented reduced parasitism and lesion size when compared to controls. Taken together, these results indicate that leishmanial SOD modulates the lymphocyte response, and that the elevation in IFN-gamma possibly accounted for the decreased skin parasitism observed in immunized animals.
- In Vivo Antileishmanial Activity of Plant-Based Secondary Metabolites(2013) PASSERO, Luiz Felipe Domingues; LAURENTI, Marcia D.; SANTOS-GOMES, Gabriela; CAMPOS, Bruno Luiz Soares; SARTORELLI, Patricia; LAGO, Joao Henrique G.
- Treatment with triterpenic fraction purified from Baccharis uncinella leaves inhibits Leishmania (Leishmania) amazonensis spreading and improves Th1 immune response in infected mice(2014) YAMAMOTO, Eduardo Seiji; CAMPOS, Bruno Luiz S.; LAURENTI, Marcia Dalastra; LAGO, Joao H. G.; GRECCO, Simone dos Santos; CORBETT, Carlos E. P.; PASSERO, Luiz Felipe D.The current medications used to treat leishmaniasis have many side effects for patients; in addition, some cases of the disease are refractory to treatment. Therefore, the search for new leishmanicidal compounds is indispensable. Recently, it was demonstrated that oleanolic- and ursolic-containing fraction from Baccharis uncinella leaves eliminated the promastigote and amastigote forms of Leishmania (Leishmania) amazonensis and L. (Viannia) braziliensis without causing toxic effects for J774 macrophages. Thus, the aim of the present work was to characterize the therapeutic effect of the triterpenic fraction in L. (L.) amazonensis-infected BALB/c mice. Oleanolic- and ursolic acid-containing fraction was extracted from B. uncinella leaves using organic solvents and chromatographic procedures. L. (L.) amazonensis-infected BALB/c mice were treated intraperitoneally with triterpenic fraction during five consecutive days with 1.0 and 5.0 mg/kg of triterpenic fraction, or with 10.0 mg/kg of amphotericin B drug. Groups of mice treated with the triterpenic fraction, presented with decreased lesion size and low parasitism of the skin-both of which were associated with high amounts of interleukin-12 and interferon gamma. The curative effect of this fraction was similar to amphotericin B-treated mice; however, the final dose, required to eliminate amastigotes, was lesser than amphotericin B. Moreover, triterpenic fraction did not cause microscopic alterations in liver, spleen, heart, lung, and kidney of experimental groups. This work suggests that this fraction possesses compounds that are characterized by leishmanicidal and immunomodulatory activities. From this perspective, the triterpenic fraction can be explored as a new therapeutic agent for use against American Tegumentar Leishmaniasis.