ABSTRACT
Leishmaniasis is a group of diseases caused by protozoan parasites of the Leishmania genus. Previous studies have shown that a DNA vaccine encoding Leishmania donovani antigen nucleoside hydrolase 36 and L. mexicana glycoprotein 63 is protective in mice. We investigated here the efficacy of this DNA vaccine to induce protection in golden hamsters. Male hamsters were more susceptible to infection by Leishmania mexicana than females. Following immunization with two doses of the DNA vaccine, only females resulted protected while males developed normal lesions.
Subject(s)
Cricetinae/parasitology , Glycoproteins/immunology , Leishmania mexicana/drug effects , Leishmaniasis, Cutaneous/immunology , Leishmaniasis, Cutaneous/veterinary , N-Glycosyl Hydrolases/immunology , Protozoan Proteins/immunology , Vaccines, DNA/therapeutic use , Animals , Cricetinae/immunology , Female , Immunization/methods , Immunization/veterinary , Leishmania mexicana/enzymology , Male , Mice , Sex CharacteristicsABSTRACT
Leishmania mexicana is the main causal agent of cutaneous leishmaniasis in the Yucatán peninsula in Mexico. Control of this disease is associated with a Th1-type immune response and garlic extract has been reported as a Th1 immunomodulator in BALB/c mice infected with Leishmania major. In this study, we investigated the effect of garlic extracts on L. mexicana infection in vivo and in vitro. Garlic extract reduced footpad lesions in L. mexicana-infected BALB/c mice by inducing IFN-gamma production from T cells. In vitro, garlic extract reduced macrophage infection through induction of nitric oxide (NO) production. Garlic extract may thus act on both T cells and macrophages to stimulate IFN-gamma production and NO synthesis for parasite killing. A 10- to 14-kDa fraction was identified as responsible for the in vitro effect of the whole extract and may lead to the identification of novel immunomodulating drugs and therapeutic alternatives for the treatment of leishmaniasis.
Subject(s)
Garlic/immunology , Leishmaniasis, Cutaneous/drug therapy , Macrophages/drug effects , Nitric Oxide/biosynthesis , Phytotherapy , Animals , Female , Flow Cytometry , Garlic/chemistry , Interferon-gamma/drug effects , Interferon-gamma/immunology , Interferon-gamma/metabolism , Leishmania mexicana , Leishmaniasis, Cutaneous/immunology , Macrophages/metabolism , Macrophages/microbiology , Mice , Mice, Inbred BALB C , Nitric Oxide/immunology , Plant Extracts/immunology , Plant Extracts/therapeutic use , T-Lymphocytes/drug effects , T-Lymphocytes/immunologyABSTRACT
Methanol extracts were prepared from different parts of 18 plants collected in the Yucatan peninsula and evaluated in an in vitro bioassay for leishmanicidal activity against Leishmania mexicana promastigotes. The ten most potent plant extracts (IC(50)<50 microg/ml) were Aphelandra scabra leaves, Byrsonima bucidaefolia bark, Byrsonima crassifolia bark, Clusia flava leaves, Cupania dentata bark, Diphysa carthagenensis leaves, Dorstenia contrajerva whole plant, Milleria quinqueflora roots, Tridax procumbens whole plant, and Vitex gaumeri bark.
Subject(s)
Antiprotozoal Agents/pharmacology , Leishmania mexicana/drug effects , Phytotherapy , Plant Extracts/pharmacology , Plants, Medicinal , Animals , Antiprotozoal Agents/administration & dosage , Antiprotozoal Agents/therapeutic use , Inhibitory Concentration 50 , Leishmaniasis, Cutaneous/drug therapy , Medicine, Traditional , Mexico , Parasitic Sensitivity Tests , Plant Bark , Plant Extracts/administration & dosage , Plant Extracts/therapeutic use , Plant LeavesABSTRACT
We investigated whether the infection with Trypanosoma cruzi in rats could produce functional alterations of the central nervous system. The experimental group received an injection of 150,000 trypomastigotes / rat, whereas the control group received a saline injection. Spontaneous alternation behavior (SAB) tests and sleep-wake cycle recordings were obtained at the end of the parasitaemia. Results showed that the infected animals had significant sleep impairments, as denoted by an increase in the number of wake periods and a reduction of rapid eye movement sleep amount. SAB performance was also found to be impaired in these animals, as compared to the control group. Our results suggest that the rat is a suitable model for brain dysfunction studies in Chagas' disease.
