Comparação dos efeitos das folhas de Cestrum axillare Vell. com as saponinas isoladas em caprinos

ABSTRACT: Cestrum axillare Vell. (formerly Cestrum laevigatum Schltd.), family Solanaceae, is the most important hepatotoxic plant in Brazil that causes acute poisoning. It occurs in the Southeast and Center-West regions and in coastal areas of the Northeast Brazil. Spontaneous poisoning was described in cattle, goats and sheep, with clinical signs evidenced within 24 hours after ingestion of the leaves and death within 48 hours after signs onset. The clinical signs observed in acute poisoning are apathy, anorexia, ruminal arrest, arched back, constipation with feces in small spheres, sometimes covered with mucus and blood streaks, muscle tremors, staggering gait and sometimes sialorrhoea. Neurological signs may be observed, due to interference in the urea cycle due to hepatic insufficiency resulting in hyperammonemia (hepatic encephalopathy). The main pathological finding is centrilobular hepatic necrosis. The toxic principle present in C. axillare was not yet definitively proven, but some authors attribute the toxicity of the plant to the presence of saponins gitogenin and digitogenin. However, it has not been determined whether the saponins present in C. axillare are responsible for the hepatotoxic effect of the plant. Thus, the objective of this work is to determine if the saponins are the compounds responsible for the hepatotoxic effects produced by the ingestion of the leaves of C axillare, using goats as experimental model. For this, the effects of the administration of the leaves were compared with those produced by the saponins isolated from the leaves in goats. Six goats were randomly assigned to three experimental groups that received [1] dry leaves of C. axillare (animals A1 and A2), [2] saponins extract from leaves (animals S1 and S2) or [3] control group (animals C1 and C2). For goats receiving the dry leaves the administered dose of plant was 10g/kg for one animal (A1) and 5g/kg for the other one (A2). For animals receiving the saponins extract, administration was done at a dose equivalent to 20g/kg repeated after 24 hours. The dry leaves administered at a dose of 10g/kg to a goat produced toxic effects, with alterations in biochemistry (indicating hepatic lesion) and histopathology showing centrilobular hepatic necrosis. At the dose of 5 g/kg of dry leaves, clinical signs of poisoning were not observed, but hepatic necrosis was found; after 15 days after the last administration, the hepatic parenchyma of this animal was already normal, with only hemorrhagic areas, demonstrating full regeneration. The administration of extracts of saponins containing gitogenin and digitogenin to goats did not produce significant toxic effects, proving that these compounds are not responsible for intoxication. In addition, goats are a good experimental model for studies of this intoxication

Immunomodulatory effects and improved prognosis of experimental autoimmune encephalomyelitis after O-tetradecanoyl-genistein treatment

AbstractExperimental autoimmune encephalomyelitis (EAE) is a murine autoimmune disease used to study multiple sclerosis (MS), a human inflammatory demyelinating disease of the central nervous system. Genistein, an isoflavonoid phytoestrogenic compound found in soy, is known to reverse clinical signs of EAE. Although genistein has some potential in clinical application, it has some disadvantages related to its chemical structure, such as rapid in vivo metabolism and a fast decline in serum after oral administration. The present work investigates the treatment of EAE by using 7-O-tetradecanoyl-genistein (TDG), a more lipophilic analog of genistein obtained by esterification. The clinical course of EAE was investigated in C57Bl/6 mice immunized with myelin oligodendrocyte glycoprotein peptide (MOG)35–55 in complete Freund's adjuvant supplemented with Mycobacterium tuberculosis H37RA. After 14days of MOG immunization, mice were treated with TDG for seven days. Numbers of IL-17-producing cells and Foxp3 by CD4+ T cells and CTLA-4 expression by CD3+ T cells from brain were determined by flow cytometry. Levels of IL-6, IFN-γ and IL-10 were evaluated by ELISA. Brain sections were stained by hematoxylin and eosin method. The data obtained indicate that TDG treatment ameliorates the clinical signs of EAE, which correlates with a decrease of IL-17-producing cells and an increase in Foxp3+CD4+ cells in the brain. TDG is also shown to enhance IL-10 production and CTLA-4 expression and to reduce IFN-γ and IL-6. Altogether, these findings suggest an immunomodulatory therapeutic role for TDG in EAE and multiple sclerosis

Phosphate fertilization on production and quality of cauliflower seeds

ABSTRACT: Due to the scarcity of information related to the effect of fertilizers on production and quality of vegetable seeds, mainly on species which present an increase in the cycle, like cauliflower, more studies are necessary about the influence of nutrients rates which provide high production of high-quality seeds. This research aimed to evaluate the influence of rates of phosphorus (P) on the production and quality of cauliflower seeds. Five rates of phosphorus were studied (0, 300, 600, 900 and 1200kg ha-1 of P2O5), in a randomized complete block design, with four replications. Production and quality (weight of a thousand seeds, germination test, first count of germination test and emergence in substrate) of the seeds and soil chemical characteristics were evaluated. The higher the rate of phosphorus, the higher P content in the soil and values of sum of bases, cation exchange capacity and saturation of bases were observed at the end of the cycle. Seed quality was not affected by P fertilization, with the exception of the weight of a thousand seeds which was adjusted to a linear model. For seed production quadratic effect was obtained. The highest weight of seeds per plant was estimated for the rate of 862kg ha-1 of P2O5