The Effect of Propolis on Th1/Th2 Cytokine Expression and Production by Melanoma-bearing Mice Submitted to Stress

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Propolis Immunomodulatory Action In Vivo on Toll-Like Receptors 2 and 4 Expression and on Pro-Inflammatory Cytokines Production in Mice

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Propolis immunomodulatory activity on TLR-2 and TLR-4 expression by chronically stressed mice

Our group has been investigating the immunomodulatory activity of propolis in stressed mice. In this work, we wish to report the action of propolis in chronically stressed mice, assessing the Toll-like receptor (TLR2 and TLR-4) expression by spleen cells and corticosterone levels as a stress indicator. Male C57BL/6 mice were divided into four groups: G1 was considered the control; G2 was treated with propolis (200mg kg(-1)); G3 was submitted to restraint stress for 14 days; and G4 was treated with propolis and immediately submitted to stress. After sacrifice, spleens were removed and TLR-2 and TLR-4 gene expression was analysed. TLR-2 and TLR-4 expression was increased in propolis-treated mice, and propolis administration to stressed mice prevented the inhibition of TLR-2 and TLR-4 expression. No differences were seen in the corticosterone levels among the groups. Propolis exerted an immunomodulatory action in chronically stressed mice, upregulating TLR-2 and TLR-4 mRNA expression, contributing to the recognition of microorganisms and favouring the initial steps of the immune response during stress.

Green Brazilian propolis action on macrophages and lymphoid organs of chronically stressed mice

Stress is a generic term that summarizes how psychosocial and environmental factors influence physical and mental well-being. The interaction between stress and immunity has been widely investigated, involving the neuroendocrine system and several organs. Assays using natural products in stress models deserve further investigation. Propolis immunomodulatory action has been mentioned and it has been the subject of scientific investigation in our laboratory. The aim of this study was to evaluate if and how propolis activated macrophages in BALB/c mice submitted to immobilization stress, as well as the histopathological analysis of the thymus, bone marrow, spleen and adrenal glands. Stressed mice showed a higher hydrogen peroxide (H2O2) generation by peritoneal macrophages, and propolis treatment potentiated H2O2 generation and inhibited nitric oxide (NO) production by these cells. Histopathological analysis showed no alterations in the thymus, bone marrow and adrenal glands, but increased germinal centers in the spleen. Propolis treatment counteracted the alterations found in the spleen of stressed mice. New research is being carried out in order to elucidate propolis immunomodulatory action during stress.

Fetotoxicity caused by the interaction between zinc and arsenic in mice

Arsenic is an environmental pollutant that induces congenital malformations in experimental models and can contribute to human birth defects. The environmental exposure to arsenic is relatively small when compared with the doses required to cause teratogenicity in mice and other laboratory animals. In order to study the action of zinc in the arsenic-induced teratogenicity, in the present work mice were either pretreated with zinc and later with arsenic or were treated simultaneously with zinc and arsenic in vivo and in vitro. Following administration of arsenate on gestation day 8, pregnant females were killed on the 17th day of gestation; maternal and fetal data were collected by laparotomy and used to calculate reproductive parameters. Fetuses were analyzed for the presence of external malformation and, after the appropriate processing, visceral and skeletal analyses were accomplished. Conceptuses were exposed in whole embryo culture to arsenicals on gestation day 8 (3-6 somite stage). After a 26 h culture period, morphological development was assessed. Neither pretreatment with zinc nor simultaneous administration of zinc prevented arsenic teratogenicity in these experimental models. (C) 2002 Wiley-Liss, Inc.

Inflammatory reaction to the human bot-fly, Dermatobia hominis, in infested and reinfested mice

Two groups of mice were infested with first stage larvae of the human bot-fly, Dermatobia hominis (Linnaeus Jr) (Diptera: Oestridae). In the first group, skin biopsies were carried out 1, 3, 5, 7, 10 and 18 days after infestation. The second group was also infested but had all the larvae removed 5 days after infestation. The mice in the latter group were reinfested 4 weeks later and skin biopsies were carried out 1, 3, 5, 7, 10 and 18 days after reinfestation. In the first group, an inflammatory reaction began slowly, the neutrophils being the main inflammatory cells, eosinophils being scarce. The reaction progressed with time, developing a necrotic halo around the larvae containing inflammatory cells surrounded by fibroblasts. The inflammation invaded the adjacent tissue. In the second group, the inflammatory reaction was intense on the day immediately after reinfestation, the pattern being changed by the presence of a large number of eosinophils. Activated fibroblasts surrounding the necrotic area around the larvae appeared 3 days after reinfestation in the second group and 7 days after infestation in the first group. The results demonstrated that the previous contact with the antigens elicited the early arrival of eosinophils, probably through the chemotactic factors liberated by mast cells in the anaphylactic reaction.

Orchidopexy restores morphometric-stereologic changes in the caput epididymis and daily sperm production in cryptorchidic mice, although sperm transit time and fertility parameters remain impaired

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Effects of the polysaccharide beta-glucan on clastogenicity and teratogenicity caused by acute exposure to cyclophosphamide in mice

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Evaluation of chemopreventive activity of glutamine by the comet and the micronucleus assay in mice's peripheral blood

This research has evaluated the effects of enteral supplementation of glutamine in clastogens and genotoxic damages caused by the acute administration of cisplatin. For this. it was utilized Swiss mice distributed in eight experimental groups: control, cisplatin, glutamine, in three different doses and the combination of these with cisplatin. The results show that the glutamine was present in neither genotoxic nor mutagenic activity. When in association with glutamine and cisplatin, in simultaneous treatment, it was verified the frequency decreased of micronuclei and comets. The damage reduction percentages to the micronucleus ranged from 95.4 to 91.8% after 24 h of administration of these compounds and 76.7 to 56.8% after 48 h. In the same time the damage reduction percentages to the comet test ranged from 117.0 to 115.0%. The results suggest that glutamine is capable of preventing genotoxic and mutagenic damage according to the experimental design proposed. (C) 2009 Elsevier B.V. All rights reserved.

Differential coronary resistance microvessel remodeling between type 1 and type 2 diabetic mice: Impact of exercise training

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Role of PKC and CaV1.2 in Detrusor Overactivity in a Model of Obesity Associated with Insulin Resistance in Mice

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Toxin jararhagin in low doses induces interstitial edema and increases the metabolic rate and red blood cells in mice

Jararhagin is a metalloproteinase from Bothrops jararaca responsible for hemorrhage, inflammation, necrosis and edema. Effects of low doses of the toxin were analyzed on the energy metabolism of mice as well as its physiological implications. Measures of O-2 consumption (VO2) were quantified after 4 and 24 h of the jarathagin administration during four weeks. Hematocrit and histology of the lungs were also analyzed after the end of the treatment. Results showed that animals that received subcutaneous doses of jararhagin had significant increase in VO2 from second (120 ng) and third weeks (60 ng) after 4 and 24 h, comparing to control, as well as in the number of erythrocytes after four weeks. Histology of the lungs showed interstitial edema within the alveolar septum. Results suggest that the jararhagin toxin caused an increase in VO2 and edema of intra-alveolar septum. The increase of the erythrocytes could be a physiological response to adjust the higher necessity of oxygen, due to diffusional abnormalities caused by the edema. Thus, low doses of jararhagin promote endothelial edema which lead to changes in several physiological conditions. (c) 2006 Elsevier Ltd. All rights reserved.

Effect of erythrosine- and LED-mediated photodynamic therapy on buccal candidiasis infection of immunosuppressed mice and Candida albicans adherence to buccal epithelial cells

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Ethanolic extract of Casearia sylvestris and its clerodane diterpen (caseargrewiin F) protect against DNA damage at low concentrations and cause DNA damage at high concentrations in mice's blood cells

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)