Antimutagenic effect of Agaricus blazei Murrill mushroom on the genotoxicity induced by cyclophosphamide

Agaricus blazei Murrill extracts have previously been shown to have anticarcinogenic and antimutagenic proper-ties. These results suggest that antimutagenic activity, besides the modulation of the immune system, might be involved in the anticarcinogenic action of A. blazei. To investigate the possible antimutagenic effect of A. blazei in vivo, we evaluated its effect on clastogenicity induced by cyclophosphamide (CP) in mice, using the micronucleus test in bone marrow (MNPCE) and in peripheral blood (MNRET). Male Swiss mice were treated with CP (25 or 50 mg/kg i.p.) or with CP plus mushroom solution at three different temperatures: 4, 21, and 60 degreesC. Aqueous solution of a mixture from various lineages of the mushroom inhibited induction of micronuclei by CP in bone marrow and in peripheral blood of mice. In contrast to the mixture of lineages, a single isolated lineage did not lead to a reduction of CP-induced MN frequencies in either bone marrow or blood cells of mice. The results suggest that under certain circumstances these mushrooms exhibit antimutagenic activities that might contribute to an anticarcinogenic effect. (C) 2001 Elsevier B.V. B.V. All rights reserved.

Diuron exposure induces systemic and organ-specific toxicity following acute and sub-chronic exposure in male Wistar rats

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

NF-kappa B signaling modulation by EBV and KSHV

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

HIV, EBV and KSHV: Viral cooperation in the pathogenesis of human malignancies

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

Sarcopenia da caquexia reumatoide: conceituação, mecanismos, consequências clínicas e tratamentos possíveis

A caquexia relacionada à artrite reumatoide é conceituada como perda involuntária de massa magra, predominantemente de músculo esquelético, que também ocorre em vísceras e sistema imune, com massa gorda estável ou um pouco elevada e com pequena ou nenhuma perda de peso. A causa é multifatorial, incluindo a produção acentuada de citocinas, principalmente TNF± e IL-1², diminuição da ação periférica da insulina e pouca atividade física. A caquexia se faz presente em doentes com AR ativa ou mesmo inativa. Neste artigo discutem-se aspectos relacionados à patogenia, implicações clínicas e possíveis opções terapêuticas.

Sequencing and expression analysis of hepcidin mRNA in donkey (Equus asinus) liver

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

Identification, characterization and expression analysis of hepcidin gene in sheep

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Uso de imunomoduladores nas enfermidades infecciosas dos animais domésticos

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Imunidade inata da glândula mamária bovina: resposta à infecção

A imunidade na glândula mamária pode ser classificada, assim como em outros sistemas, em inata ou inespecífica e adaptativa ou específica. A imunidade inata é a defesa predominante durante os estágios iniciais da infecção. As respostas inespecíficas estão presentes no local da infecção ou são ativadas rapidamente por numerosos estímulos e não aumentam pela exposição repetida ao mesmo agente etiológico. O primeiro obstáculo enfrentado por um patógeno para adentrar o úbere é composto pela barreira formada pelo esfíncter do teto e pelo tampão de queratina formado pelo epitélio queratinizado. Uma vez que o microrganismo tenha atravessado o canal do teto e alcançado a cisterna mamária, passam a atuar diversos fatores solúveis e celulares. Dentre os fatores solúveis, estão presentes: lactoperoxidase, sistema complemento, citocinas, lactoferrina, lisozima e NAGase. As defesas celulares inespecíficas na glândula mamária são representadas pelos neutrófilos, pelos macrófagos e pelas células natural killer. Na medida em que esses mecanismos funcionam adequadamente, a maioria dos patógenos será rapidamente eliminada antes que o sistema imune específico seja ativado, sem resultar em alterações na quantidade ou qualidade do leite produzido. Uma melhor compreensão sobre os mecanismos de defesa da glândula mamária e suas alterações durante os períodos críticos da infecção é imprescindível para o desenvolvimento de métodos mais eficazes de profilaxia e controle da mastite, a principal doença dos ruminantes leiteiros. O presente estudo revisou os principais aspectos responsáveis pelo desenvolvimento da imunidade inata na glândula mamária bovina.

Patterns of Gene Expression in the Bovine Corpus Luteum Following Repeated Intrauterine Infusions of Low Doses of Prostaglandin F2alpha

Natural luteolysis involves multiple pulses of prostaglandin F2alpha (PGF) released by the nonpregnant uterus. This study investigated expression of 18 genes from five distinct pathways, following multiple low-dose pulses of PGF. Cows on Day 9 of the estrous cycle received four intrauterine infusions of 0.25 ml of phosphate-buffered saline (PBS) or PGF (0.5 mg of PGF in 0.25 ml of PBS) at 6-h intervals. A luteal biopsy sample was collected 30 min after each PBS or PGF infusion. There were four treatment groups: Control (n = 5; 4 PBS infusions), 4XPGF (4 PGF infusions; n = 5), 2XPGF-non-regressed (2 PGF infusions; n = 5; PGF-PBS-PGF-PBS; no regression after treatments), and 2XPGF-regressed (PGF-PBS-PGF-PBS; regression after treatments; n = 5). As expected, the first PGF pulse increased mRNA for the immediate early genes JUN, FOS, NR4A1, and EGR1 but unexpectedly also increased mRNA for steroidogenic (STAR) and angiogenic (VEGFA) pathways. The second PGF pulse induced immediate early genes and genes related to immune system activation (IL1B, FAS, FASLG, IL8). However, mRNA for VEGFA and STAR were decreased by the second PGF infusion. After the third and fourth PGF pulses, a distinctly luteolytic pattern of gene expression was evident, with inhibition of steroidogenic and angiogenic pathways, whereas, there was induction of pathways for immune system activation and production of PGF. The pattern of PGF-induced gene expression was similar in corpus luteum not destined for luteolysis (2X-non-regressed) after the first PGF pulse but was very distinct after the second PGF pulse. Thus, although the initial PGF pulse induced mRNA for many pathways, the second and later pulses of PGF appear to have set the distinct pattern of gene expression that result in luteolysis.

Effect of cyclosporin A on alveolar bone homeostasis in a rat periodontitis model

Objectives: the administration of cyclosporin A has been associated with significant bone loss and increased bone remodeling. The present investigation was designed to evaluate the effects of cyclosporin A on alveolar bone of rats subjected to experimental periodontitis, using serum, stereometric and radiographic analysis.Methods: Twenty-four rats were divided into one of the following groups with six animals each: group I, control rats; group II, in which the animals received a cotton ligature around the lower first molars; group III, in which the rats received a cotton ligature around the lower first molars and were treated with 10 mg/(kg body weight day) of cyclosporin A; group IV, in which the rats were treated with 10 mg/(kg body weight day) of cyclosporin A. At the end of experimental period, at 30 days, animals were killed and the serum calcium and alkaline phosphatase levels were measured in all groups. The distance from the alveolar bone crest to the cemento-enamel junction was measured radiographically for each mesial surface of the lower first molars of each rat. After histological processing, the stereological parameters: volume densities of multinucleated osteoclasts (V-o), alveolar bone (V-b), marrow (V-m), and relation of eroded surface/bone surface (Es/Bs) were assessed at the mesial region of the alveolar bone.Results: Significant decreases in serum calcium were observed in those groups that received cyclosporin A therapy. No significant changes in serum alkaline phosphatase were observed. The therapy with cyclosporin A combined with the ligature placement decreased the V-b and increased the V-o, V-m and Es/Bs at the mesial surface of lower first molars. on the other hand, the radiographic data showed that cyclosporin A therapy diminished the alveolar bone loss at the mesial surface of the lower first molars.Conclusions: Therefore, within the limits of this study, we suggest that cyclosporin A at immunosuppressive levels can bring about an imbalance in the alveolar bone homeostasis in rats. However, in the presence of inflammatory stimulation, the inhibition of the immune system by cyclosporin A may decrease the initial periodontal breakdown.

Signaling pathways associated with the expression of inflammatory mediators activated during the course of two models of experimental periodontitis

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

Stimulation of IL-6 Cytokines in Fibroblasts by Toll-like Receptors 2

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Dietary intervention with narrow-leaved cattail rhizome flour (Typha angustifolia L.) prevents intestinal inflammation in the trinitrobenzenesulphonic acid model of rat colitis

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

Dietary Polydextrose Prevents Inflammatory Bowel Disease in Trinitrobenzenesulfonic Acid Model of Rat Colitis

Inflammatory bowel disease (IBD) is a multifactorial intestinal disorder that involves interactions among the immune system, genetic susceptibility, and environmental factors, especially the bacterial flora. Polydextrose, a polysaccharide constituted by 90% nondigestible and nonabsorbable soluble fibers, has several physiological effects consistent with those of dietary fibers, including proliferation of colon microflora. Because sulfasalazine presents serious side effects through long-term use at high doses, the aim of the present study was to evaluate the preventative effect of polydextrose on trinitrobenzenesulfonic acid-induced intestinal inflammation and its effects on the intestinal anti-inflammatory activity of sulfasalazine. Results indicated that polydextrose and its association with sulfasalazine present an anti-inflammatory effect that reduces myeloperoxidase activity, counteracts glutathione content, and promotes reductions in lesion extension and colonic weight/length ratio.