Chronic Aerobic Training at Different Volumes in the Modulation of Macrophage Function and in vivo Infection of BALB/c Mice by Leishmania major.

Physical inactivity is one of the main causes of chronic diseases; however, strenuous exercise can induce immunosuppression. Several studies suggest that moderate amounts of exercise lead to a Th1 response, favoring the resolution of infections caused by intracellular microorganisms, while high volumes of exercise tend to direct the response to Th2, favoring infection by them. Leishmaniasis is a parasitic disease promoted by parasites of the Leishmania genus, with clinical manifestations that vary according to the species of the parasite and the immune response of the host. The experimental Leishmania major-BALB/C mouse model provides a good model for the resistance (Th1 response) or susceptibility (Th2 response) that determines the progression of this infection. The aim of this study was to evaluate the effect of aerobic training at different volumes on modulation of in vitro macrophage infection by L. major, as well as to assess the effect of high volume (HV) aerobic training on the development of L. major in vivo in BALB/c mice. Uninfected animals were submitted to various exercise volumes: none (SED), light (LV), moderate (MV), high (HV), very high (VHV), and tapering (TAP). The macrophages of these animals were infected by L. major and the LV and MV groups showed a decrease in the infection factor, while the VHV showed an increase in the infection factor, when treated with LPS. The cytokine concentration pattern measured in the supernatants of these macrophages suggested a predominant Th1 response profile in the LV and MV groups, while the Th2 profile predominated in the VHV and TAP groups. Groups of BALB/C mice infected with L. major were subjected to high volume (iHV) or non-periodized high volume (iNPHV) exercise or kept sedentary (iSED). The exercised animals suffered a significant increase in injuries caused by the parasites. The animals in the group submitted to high volume exercise (iHV) showed visceralization of the infection. These data strongly suggest that a very high volume of aerobic training increased the susceptibility of BALB/C mice to L. major infection, while moderate distribution of training loads promoted immunological balance, better controlling the infection by this parasite.

Novel antiplatelet role for a protein disulfide isomerase-targeted peptide: evidence of covalent binding to the C-terminal CGHC redox motif.

Essentials Inhibitors of protein disulfide isomerase (PDI) have been considered a new antithrombotic class. CxxC is a PDI-targeted peptide that has been previously shown to inhibit its reductase activity. CxxC binds to surface PDI and inhibits ADP- and thrombin-evoked platelet activation and aggregation. CxxC binds to Cys400 on CGHC redox motif of PDI a' domain, a site for PDI prothrombotic activity. SUMMARY: Background Protein disulfide isomerase (PDI) plays a major role in platelet aggregation, and its inhibitors have emerged as novel antithrombotic drugs. In previous work, we designed a peptide based on a PDI redox motif (CGHC) that inhibited both PDI reductase activity and PDI-modulated superoxide generation by neutrophil Nox2. Thus, we hypothesized that this peptide would also inhibit platelet aggregation by association with surface PDI. Methods Three peptides were used: CxxC, containing the PDI redox motif; Scr, presenting a scrambled sequence of the same residues and AxxA, with cysteines replaced by alanine. These peptides were tested under platelet aggregation and flow cytometry protocols to identify their possible antiplatelet activity. We labeled membrane free thiol and electrospray ionization liquid chromatography tandem mass spectrometry to test for an interaction. Results CxxC decreased platelet aggregation in a dose-dependent manner, being more potent at lower agonist concentrations, whereas neither AxxA nor Scr peptides exerted any effect. CxxC decreased aIIbb3 activation, but had no effect on the other markers. CxxC also decreased cell surface PDI pulldown without interfering with the total thiol protein content. Finally, we detected the addition of one CxxC molecule to reduced PDI through binding to Cys400 through mass spectrometry. Interestingly, CxxC did not react with oxidized PDI. Discussion CxxC has consistently shown its antiplatelet effects, both in PRP and washed platelets, corroborated by decreased aIIbb3 activation. The probable mechanism of action is through a mixed dissulphide bond with Cys400 of PDI, which has been shown to be essential for PDI's actions. Conclusion In summary, our data support antiplatelet activity for CxxC through binding to Cys400 in the PDI a0 domain, which can be further exploited as a model for sitedriven antithrombotic agent development.

Exercise improves the Th1 response by modulating cytokine and NO production in BALB/c mice.

Physical exercise can improve health and may lead to changes in the functionality of the immune system. Moderate intensity exercise can reduce the risk of infection by shifting the overall immune response towards a T helper type 1 pattern. This study investigates the effect of 12 weeks of swimming on the cytokine profile of lymph node cells and macrophages and of the nitric oxide production by these cells. BALB/c mice were divided into 2 groups. The exercise group was subjected to swimming exercise. Lymph node cells culture showed that concentrations of interferon-γ and tumour necrosis factor-α were higher in the exercised group, while levels of interleukine-4 and interleukine-10 were significantly decreased in this group. The interleukine-10/interferon-γ ratio tended towards a T helper type 1 profile. Moreover, macrophages isolated from exercised mice produced more interleukine-12 and tumour necrosis factor-α following lipopolysaccharide stimulus. Challenging these macrophages with Leishmania major resulted in higher interleukine-12 production than was observed with macrophages from the control group. Nitric oxide production was increased in macrophages isolated from exercised group following lipopolysaccharide stimulus but not following infection with Leishmania major. These data suggest that exercise biases the immune system towards a T helper type 1 response profile.

Immunomodulatory pretreatment with Kalanchoe pinnata extract and its quercitrin flavonoid effectively protects mice against fatal anaphylactic shock.

Previously, we reported the immunosuppressive action of the aqueous extract of Kalanchoe pinnata (Kp) in mice. In the present study, we report on the protective effect of Kp in fatal anaphylactic shock, likewise a Th2-driven immunopathology, and the identification of its active component. Mice daily treated with oral Kp during hypersensitization with ovalbumin were all protected against death when challenged with the allergen, as compared with the 100% mortality in the untreated group. A single intraperitoneal dose 3 h prior to challenge was partially effective. Oral protection was accompanied by a reduced production of OVA-specific IgE antibodies, reduced eosinophilia, and impaired production of the IL-5, IL-10 and TNF-alpha cytokines. In vitro, Kp prevented antigen-induced mast cell degranulation and histamine release. Oral treatment with the quercitrin flavonoid isolated from Kp prevented fatal anaphylaxis in 75% of the animals. These findings indicate that oral treatment with Kp effectively downmodulates pro-anaphylactic inducing immune responses. Protection achieved with quercitrin, although not maximal, suggests that this flavonoid is a critical component of Kp extract against this extreme allergic reaction.

Toxicological analysis and effectiveness of oral Kalanchoe pinnata on a human case of cutaneous leishmaniasis.

Leishmaniasis is an extremely difficult disease to treat. Previously, it was shown that oral Kalanchoe pinnata (Kp) leaf extract is strongly effective against murine leishmaniasis. Here, it is shown that the serum levels of alanine-aminotransferase (ALT), aspartate-aminotransferase (AST), urea and alkaline phosphatase were unchanged in mice orally treated with supraoptimal Kp doses for 30 days, indicating the absence of chronic toxicity to the liver, heart or kidney. Additionally, evidence is presented that human leishmaniasis may also be controlled with oral Kp. A 36-year-old man with an active cutaneous leishmaniasis was orally treated with 30 g wet weight of Kp leaves/day for 14 days. During the Kp treatment, the lesion stopped growing and slightly decreased. No adverse reactions or toxicity was observed. This study reports for the first time that Kalanchoe pinnata contains substances potentially active and safe for the oral treatment of human cutaneous leishmaniasis.

Isolation and chemical analysis of a fatty acid fraction of Kalanchoe pinnata with a potent lymphocyte suppressive activity.

Previously we demonstrated that Kalanchoe pinnata (KP) leaf extracts inhibited in vitro lymphocyte proliferation and showed in vivo immunosuppressive activity. Here we attempt to identify the immunosuppressive substances present in KP guided by the lymphoproliferative assays. From the ethanolic extract was purified a fraction (KP12SA) twenty-fold more potent to block murine lymphocyte proliferation than the crude extract. Chemical analysis by 1H- and 13C-NMR, IR and GC-MS of KP12SA (methylated sample) showed 89.3% of palmitic acid (C16), 10.7% of stearic acid (C18) and traces of arachidic (C20) and behenic acids (C22). This study provides evidence that fatty acids present in Kalanchoe pinnata may be responsible, at least in part, for its immunosuppressive effect in vivo.

The anti-leishmanial effect of Kalanchoe is mediated by nitric oxide intermediates.

We have previously shown that oral treatment with the leaf extract of the plant Kalanchoe pinnata (Kp) significantly decreases the lesion size and the parasite load in BALB/c mice infected with Leishmania amazonensis. Here we report on the mode of action of Kp, particularly on the induction of nitric oxide (NO) production by macrophages. We observed that Kp has no direct inhibitory activity on extracellular promastigotes, but effectively decreases the intracellular amastigote growth in a dose-related fashion. A 58% reduction in amastigote growth induced by 500 micrograms/ml Kp was associated with a 6-fold increase in the production of NO by the macrophages. IFN-gamma synergistically enhanced the NO-stimulating effect of Kp in culture. Co-treatment with the inducible NO synthase enzyme inhibitor L-NG-monomethyl-arginine abolished the antileishmanial effect of Kp in vitro and in L. amazonensis-infected BALB/c mice. These results indicate that the protective effect of Kp in leishmaniasis may not be due to a direct effect on the parasite itself but rather to activation of the reactive nitrogen intermediates pathway of macrophages.

Therapeutic effect of oral Kalanchoe pinnata leaf extract in murine leishmaniasis.

The effect of a leaf extract from Kalanchoe pinnata (Kp) was investigated in BALB/c mice infected with Leishmania amazonensis. Oral treatment with Kp significantly delayed onset of disease as compared to untreated mice or mice receiving Kp by the intravenous or topical routes. When initiated at early stages of infection, daily oral doses of 8 mg prevented lesion growth and the effect was long-lasting, comparable to the reference antileishmanial drug Glucantime. The decreased lesion growth using the oral route was accompanied by a significant decrease in the number of viable parasites. Protection was accompanied by a diminished capacity of animals to develop delayed-type hypersensitivity and to produce specific antibodies.

[An oral health program for preschool children in Araraquara, SP-results during 1988]. / O programa de saúde bucal para crianças pré-escolares em Araraquara-SP-O desempenho em 1988.

This paper reports the composition change of the dmf-teeth index, outcome from dental health program for the 3 to 6 year old pre-school children population, enrolled in kindergartens in Araraquara-SP, in 1988. The program performance promotes a major contribution of the "f" component to the dmf-teeth index.