RESUMO
Gut dysbiosis is considered a risk factor for Parkinson's disease (PD), and chronic treatment with probiotics could prevent it. Here we report the assessment of a probiotic mixture [Lacticaseibacillus rhamnosus GG (LGG), and Bifidobacterium animalis lactis BB-12 (BB-12)] administered to male rats 2 weeks before and 3 weeks after injecting 6-hydroxydopamine (6-OHDA) into the right striatum, a model that mimics the early stages of PD. Before and after lesion, animals were subjected to behavioral tests: narrow beam, cylinder test, and apomorphine (APO)-induced rotations. Dopaminergic (DA) denervation and microglia recruitment were assessed with tyrosine hydroxylase (TH+) and ionized calcium-binding protein-1 adapter (Iba1+) immunostaining, respectively. Post 6-OHDA injury, rats treated with sunflower oil (probiotics vehicle) developed significant decrease in crossing speed and increases in contralateral paw slips (narrow beam), forepaw use asymmetry (cylinder), and APO-induced rotations. In striatum, 6-OHDA eliminated ≈2/3 of TH+ area and caused significant increase of Iba1+ microglia population. Retrograde axonal degeneration suppressed ≈2/5 of TH+ neurons in the substantia nigra pars compacta (SNpc). In hemiparkinsonian rats, probiotics treatment significantly improved the crossing speed, and also reduced paw slips (postlesion days 14 and 21), the loss of TH+ neurons in SNpc, and the loss of TH+ area and of Iba1+ microglia count in striatum, without affecting the proportion of microglia morphological phenotypes. Probiotics treatment did not attenuate forepaw use asymmetry nor APO-induced rotations. These results indicate that the mixture of probiotics LGG and BB-12 protects nigrostriatal DA neurons against 6-OHDA-induced damage, supporting their potential as preventive treatment of PD.
Assuntos
Bifidobacterium animalis , Lacticaseibacillus rhamnosus , Transtornos Motores , Doença de Parkinson , Probióticos , Ratos , Masculino , Animais , Oxidopamina , Bifidobacterium animalis/metabolismo , Doença de Parkinson/patologia , Microglia/metabolismo , Lacticaseibacillus , Substância Negra/metabolismo , Transtornos Motores/patologia , Corpo Estriado/metabolismo , Neurônios Dopaminérgicos/metabolismo , Dopamina , Apomorfina/farmacologia , Tirosina 3-Mono-Oxigenase/metabolismo , Probióticos/farmacologiaRESUMO
Blueberries (BB) are rich in antioxidant polyphenols, and their intake could prevent Parkinson's disease (PD). Here we assessed whether rats chronically fed dried raw BB develop resistance to dopaminergic denervation and motor disorders caused by unilateral intrastriatal injection of 6-hydroxydopamine (6-OHDA), a dopaminergic neurotoxin acting mainly by inducing oxidative stress. Male rats were fed either with LabDiet® alone or supplemented with 3% lyophilized raw BB for 2 weeks before and 3 weeks after injecting 6-OHDA (day 0) or vehicle (mock lesion) into the right striatum. The cylinder test was performed on days -14, -7, -1, +7, +14, and +21; the percentage of ipsilateral forepaw (IF) use asymmetry was determined by counting the wall contacts made with either forepaw or with both. Apomorphine (0.25 mg/kg, s.c.)-induced rotation was performed on days -1, +7, +14, and +21. Full contralateral rotations were counted in 3-min periods, every 15 min, up to 90 min. Striatal slices were immunostained for tyrosine hydroxylase (TH) and the ionized calcium-binding protein-1 adapter (Iba1) [immunoreactive area or microglia count in right striatum expressed as % of the left striatum]. Antioxidants in BB methanolic extracts neutralized the free radical 2,2-diphenyl-1-picrylhydrazyl in a concentration-dependent manner. Anthocyanins have been reported as the most abundant polyphenols in BB. Using the pH differential method, the total anthocyanin content (malvidin-3-glucoside equivalents) in raw BB averaged 21.04 mg/g dry weight. The range of anthocyanin intake by rats throughout the study varied from 37.7 to 72.2 mg/kg body weight. The time and food type factors, as well as their interaction were significant according to two-way RM-ANOVA in both the apomorphine-induced rotations and the cylinder test. Compared with LabDiet® alone, chronic supplementation with 3% dried raw BB decreased apomorphine-induced rotations on days +14 and +21 (p < 0.001) and produced a 46% reduction in total rotations post-surgery (p < 0.05), but only caused a partial, non-significant, decrease of IF asymmetry. BB supplementation reduced TH loss in the striatum (p < 0.05) but did not attenuate the increase of Iba1+ microglia. The consumption of 3% dried raw blueberries attenuates dopaminergic denervation and partially reverses motor disorders in the 6-OHDA-induced PD model in rats. The phytochemicals of raw blueberries that contribute to the observed neuroprotective effect are yet to be identified.
Assuntos
Apomorfina , Mirtilos Azuis (Planta) , Animais , Apomorfina/farmacologia , Corpo Estriado , Masculino , Oxidopamina , Ratos , Substância NegraRESUMO
In order to test the influence of the sympathetic nervous system on Leishmania mexicana infection, groups of female BALB/c mice were treated (i.p.) with the non-selective ß-adrenergic receptor (ß-AR) antagonist (S)-propranolol (5mg/kg thrice a day), the ß2-AR agonist clenbuterol (1mg/kg once a day) or the α2-AR antagonist yohimbine (2mg/kg twice a day) during 5days. During the second day of treatments, mice were inoculated in the footpad with 1×10(6) or 1×10(3) metacyclic promastigotes of L. mexicana mexicana (LV4). The lesion size was measured weekly, and parasite burden on week 12. In mice treated with (S)-propranolol, the percentage of splenic T lymphocytes producing IFN-γ after antigen challenge was determined by flow cytometry. In mice infected with 1×10(6) parasites, only (S)-propranolol caused a reduction of footpad swelling (p<0.05, weeks 11-12), without effects on parasite burden, or in the percentage of IFN-γ-immunopositive CD4(+) or CD8(+) T lymphocytes. In mice infected with 1×10(3) parasites, the effects of treatments vs. control group were as follows: (a) inhibition of footpad swelling by (S)-propranolol (p<0.01, weeks 3-12), clenbuterol (p<0.05, weeks 7-10), and yohimbine (p<0.01, week 7); (b) a decrease of the parasite burden by (S)-propranolol (p<0.01) and yohimbine (p<0.05); (c) in control mice the percentage of CD4(+) T-cells producing IFN-γ was 6.2±0.5%, while in those treated with (S)-propranolol it increased to 8.7±0.6% (p<0.01); (d) in control mice the percentage of CD8(+) T-cells producing IFN-γ was 3.1±0.4%, while in those treated with (S)-propranolol it increased to 10.4±0.2% (p<0.01). These results indicate that the blockade of ß-ARs during infection of BALB/c mice with an inoculum of L. mexicana mexicana similar to that delivered by the bite of a sand fly produces a Th1 bias in the immune response, favoring an increment of T lymphocytes secreting IFN-γ, which correlated with a reduced parasite burden (p<0.05, Spearman's test). We suggest that ß-AR antagonists could be of therapeutic value, either as treatment or as adjuvant of vaccines for L. mexicana.
Assuntos
Antagonistas Adrenérgicos beta/administração & dosagem , Linfócitos T CD4-Positivos/efeitos dos fármacos , Linfócitos T CD8-Positivos/efeitos dos fármacos , Leishmania mexicana/imunologia , Leishmaniose Cutânea/tratamento farmacológico , Propranolol/administração & dosagem , Agonistas de Receptores Adrenérgicos alfa 2/administração & dosagem , Agonistas Adrenérgicos beta/administração & dosagem , Animais , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/parasitologia , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/parasitologia , Clembuterol/administração & dosagem , Feminino , Humanos , Interferon gama/metabolismo , Vacinas contra Leishmaniose/administração & dosagem , Leishmaniose Cutânea/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Carga Parasitária , Psychodidae/imunologia , Equilíbrio Th1-Th2/efeitos dos fármacos , Ioimbina/administração & dosagemRESUMO
DNA vaccines have been able to induce partial protection against infection with Leishmania in mice, but it is still necessary to increase their efficacy. In the present study we evaluated aluminium phosphate as an adjuvant of different formulations and doses of DNA vaccines against L. mexicana in BALB/c mice. Aluminium phosphate had no effect on the humoral response induced by a high dose (100 microg) DNA vaccine, but slightly increased the cellular response and the protection against infection. It also allowed a non-immunoprotective low dose (20 microg) DNA vaccine encoding L. mexicana GP63 and Leishmania donovani NH36 to become protective. Aluminium phosphate may thus be an effective, low cost and safe adjuvant for DNA vaccines, and the vaccine formulation described here may be an excellent candidate for further vaccine development against Leishmania.
Assuntos
Adjuvantes Imunológicos/farmacologia , Compostos de Alumínio/farmacologia , Leishmania mexicana/imunologia , Leishmaniose Cutânea/imunologia , Leishmaniose Cutânea/prevenção & controle , Fosfatos/farmacologia , Vacinas Protozoárias/imunologia , Adsorção , Animais , Anticorpos Antiprotozoários/imunologia , Relação CD4-CD8 , Proliferação de Células/efeitos dos fármacos , Química Farmacêutica , Feminino , Interferon gama/biossíntese , Cinética , Leishmania donovani/imunologia , Leishmania mexicana/genética , Linfócitos/efeitos dos fármacos , Linfócitos/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Plasmídeos/genética , Vacinas Protozoárias/genética , Vacinas de DNA/genética , Vacinas de DNA/imunologiaRESUMO
The fucose-mannose ligand (FML) complex of Leishmania donovani is a promising vaccine candidate against murine and canine visceral leishmaniasis, and its main component is a 36-kDa nucleoside hydrolase (NH36). In this study, we tested the immune response and protection induced by the purified FML, the recombinant NH36 (rNH36), and NH36 DNA vaccines against the agents of visceral (L. chagasi) and cutaneous (L. mexicana) leishmaniasis in BALB/c mice. Mice developed weak humoral response to the vaccines alone, except for those immunized with FML. However, all three vaccine groups presented elevated immunoglobulin G (IgG), IgG1, and IgG2a levels after infection with L. chagasi, whereas no differences were observed between vaccine and control groups after infection with L. mexicana. A strong intradermal reaction to L. donovani and L. mexicana antigens was observed in mice immunized with rNH36 or FML, whereas mice immunized with NH36 DNA only reacted against L. donovani antigens. Experimental infection of immunized mice demonstrated that FML and rNH36 induced significant protection against L. chagasi infection with reductions in parasite loads of 79%. FML also conferred partial protection against L. mexicana infection. The best protection was observed in mice immunized with the VR1012-NH36 DNA vaccine, which induced an 88% reduction in L. chagasi parasite load and a 65% reduction in L. mexicana lesion size. Fluorescence-activated cell sorting analysis indicated the DNA vaccine induced a two- to fivefold increase in gamma interferon-producing CD4(+) T cells, indicating a Th1-type immune response. Our results showed that the NH36 DNA vaccine induced a strong immunoprotection against visceral and cutaneous leishmaniasis, suggesting that this DNA vaccine represents a very good candidate for use against several Leishmania species.