ABSTRACT
A leishmaniose continua sendo um problema de saúde pública mundial. As opções terapêuticas limitadas, a toxicidade dos fármacos disponíveis e os relatos de resistência reforçam a necessidade do desenvolvimento de novas opções terapêuticas. Neste contexto, nós demonstramos previamente que o dietilditiocarbamato (DETC), um inibidor da enzima superóxido dismutase1 (SOD1), pode diminuir a infecção por L. braziliensis, in vivo. Neste trabalho, nós testamos o DETC numa formulação tópica empregando membranas de celulose bacteriana (BC-DETC). O tratamento de macrófagos murinos infectados por Leishmania com BC-DETC resultou na morte dos parasitas intracelulares de forma direta e dose-dependente, sem evidência de efeito tóxico para as células hospedeiras. A morte parasitária, in vitro, foi associada com a diminuição da atividade da SOD1, em paralelo com o aumento da produção de superóxido e decitocinas pró-inflamatórias. A eficácia de BC-DETC, in vivo, foi demonstrada em camundongos BALB/c infectados com L. braziliensis. A aplicação tópica de BC-DETC à lesão cutânea diminuiu significativamente a úlcera na orelha e a carga parasitária no sítio de infecção. Adicionalmente, a resposta inflamatória, avaliada pela expressão de IFN-γ e TNF-α, foi suprimida in situ, bem como na resposta de memória (recall) usando células do linfonodo drenante. Finalmente, BC-DETC foi capaz de reduzir a carga parasitária em macrófagos humanos, um efeito que foi revertido na presença de antioxidante. Conjuntamente, estes resultados apontam para a viabilidade do uso de BC-DETC como uma nova formulação para a quimioterapia da leishmaniose cutânea causada por L. braziliensis.
Leishmaniasis remains a worldwide public health problem. The limited therapeutic options, drug toxicity and reports of resistance reinforce the need for the development of new treatment options. Among these options, we previously showed that diethyldithiocarbamate (DETC), a superoxide dismutase 1 inhibitor (SOD1), can decrease L. braziliensis infection, in vivo. Herein, we tested DETC in a topical formulation employing bacterial cellulose membranes (BC-DETC). Treatment of leishmania-infected murine macrophages with BC-DETC resulted in a direct and dose-dependent killing of intracellular parasites, without pronounced toxic effects to host cells. In vitro parasite killing was associated with decreased SOD1 activity paralleled by increased superoxide and pro inflammatory cytokine production. In vivo efficacy of BC-DETC was then demonstrated in L. braziliensis-infected BALB/c mice. Topical application of BC-DETC to dermal lesions significantly decreased ear thickness and parasite load at the infection site. Additionally, the inflammatory response, namely expression of IFN-γ and TNF-α, was down modulated in situ as well as in recall responses employing draining lymph node cells. Finally, BC-DETC was also capable of decreasing parasite load within human macrophages, an effect that was reversed in the presence of anti-oxidants. Collectively, these results point to the feasibility of using BC-DETC as a new topical formulation for the chemoprophylaxis of cutaneous leishmaniasis caused by L. braziliensis.
Subject(s)
Leishmaniasis, Cutaneous/complications , Leishmaniasis, Cutaneous/diagnosis , Leishmaniasis, Cutaneous/immunology , Leishmaniasis, Cutaneous/parasitology , Leishmaniasis, Cutaneous/pathology , Leishmaniasis, Cutaneous/prevention & control , Leishmaniasis, Cutaneous/therapy , Leishmaniasis, Cutaneous/transmissionABSTRACT
Objective To examine the effects of propofol, midazolam and pyrrolidine dithiocarbamate (PDTC) on acute lung injury (ALI) induced by normothermic cardiopulmonary bypass (CPB) .Methods Twenty-six adult SD rats of both sexes weighing 350-450 g were randomly divided into 4 groups: group I midazolam (MZ, n = 7); group 11 MZ + PDTC ( n = 7); group III propofol (PROP, n = 7) and group IV sham operation ( n = 5). The animals were premedicated with intraperitoneal (i.p.) atropine 1 mg?kg-1 and anesthetized with i.p. midazolam 4 mg?kg-1 and fentanyl 150?g?kg-1 in group I , II and IV or with i.p. propofol 30mg?kg-1 and fentanyl 150 ?g?kg-1 in group III . CPB was performed at a flow rate of 100 ml?kg-1? min-1 for 60 min. In group II PDTC 100 mg?kg-1 was given i.p. 30 min before CPB. In sham operation group the animals were anesthetized, intubated and mechanically ventilated but underwent no CPB. Arterial blood samples were taken before initiation of CPB (T1 ) , at the end of CPB (T2) and 60 min after CPB (T3) for blood gas analysis and determination of the expression of CD11b on neutrophils by flow cytometry. Respiratory index (RI) was calculated at T1 and T3 . The animals were killed at 60 min after CPB and the lungs were removed for broncho-alveolar lavage. PMN count, protein and IL-8 concentration of broncho-alveolar lavage fluid (BALF) and lung MDA content were determined. The lung histology was also examined. Results RI was significantly increased at T3 as compared to T1 in group MZ ( P
ABSTRACT
Objective To investigate the effects of pyrrolidine dithiocarbamate (PDTC) on plasma concentrations of proinflammatory cytokines and myocardial energy metabolism induced by cardiopulmonary bypass (CPB) .Methods Twelve healthy mongrel dogs of both sexes weighing 13.5-17.5 kg were randomly divided into 2 groups (n = 6 in each group) : PDTC group and control group. The animals were anesthetized with intraperitoneal 2.5% pentobarbital sodium 25 mg?kg-1, intubated and mechanically ventilated. In PDTC group PDTC 30 mg?kg-1 was given i.v. after tracheal intubation while in control group normal saline was given instead of PDTC. Aorta was clamped for 60 min and then undamped for 60 min reperfusion during CPB. Blood samples were taken before (baseline), 30 and 60 min after aortic clamping and 30 and 60 min after aortic unclamping for determination of plasma concentrations of TNF-? and IL-1?. Myocardial tissue was obtained before and 60 min after aortic clamping and 60 min after aortic unclamping for determination of myocardial content of adenine nucleotide (ATP, ADP, AMP, TAN, EC) and expression of ICAM-1 protein.Results Plasma TNF-? concentration was increased after aortic cross-clamping as compared to the baseline value before clamping in both groups but the TNF-? concentration was significantly lower in PDTC group than in control group (P
ABSTRACT
Objective To evaluate the myocardial protective effects of pinacidil combined with pyrrolidine dithiocarbamate (PDTC) against ischemia-reperfusion (I/R) injury to the isolated rabbit hearts and investigate its mechanisms. Methods One-hundred and twelve Japanese long-ear white rabbits of both sexes weighing 1.8-8.2 kg were killed by a knock to the head after heparinization. Their hearts were immediately removed and mounted on Langendorff apparatus and perfused with oxygenated K-H solution at 371 . Of the 112 isolated hearts 96 were randomized into 6 groups with 16 hearts in each group of which 8 hearts underwent 60 min reperfusion and another 8 hearts 120min reperfusion after 40min global myocardial ischemia: the hearts were perfused with K-H solution in group Ⅰ(K); with St Thomas Ⅱ solution in group Ⅱ(S); with pinacidil in group Ⅲ(P); with PDTC + K-H solution in group Ⅳ(PK); with PDTC + St Thomas Ⅱ solution in group Ⅴ(PS) and with PDTC + pinacidil in group Ⅵ(PP) . The rest of the 112 hearts (16 hearts) were perfused with K-H solution for 10 min. Then myocardial tissue was obtained for immuno-histochemical examination (SABC staining) used as normal control value.(1) Time of resumption of heart beat (from the beginning of reperfusion to the resumption of heart beat) was recorded; (2) left ventricular systolic and end-diastolic pressure (LVSP, LVEDP) and + dp/dtmax were monitored; (3) effluent from coronary sinus was collected at 60 min of reperfusion for determination of TNF-? concentration and (4) myocardial tissue was obtained at the end of reperfusion for determination of expression of NF-?B p65 and ICAM-1 in myocardium. Results (1) The heart beat resumption time was significantly shorter in group PP, PS and P than in the other 3 groups (P