Atrazine levels in the Jaboticabal water stream (Sao Paulo State, Brazil) and its toxicological effects on the pacu fish Piaractus mesopotamicus

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Toxicological and histopathological effects of hydramethylnon on Atta sexdens rubropilosa (Hymenoptera: Formicidae) workers

The leaf-cut ants are important agricultural pest, because they can cause intense defoliation in plants and destroy large areas cultivated. Although there are several works for the control of these insects by examining the toxicity of natural chemical compounds on various species of ants, few are focused on analyses of morphological changes caused in the affected organs. The aim of this study was to evaluate the effects of hydramethylnon on Atta sexdens rubropilosa workers through toxicological bioassays and morphological analysis of the post-pharyngeal glands, midgut, and Malpighian tubules of these ants. Hydramethylnon dissolved either in acetone (HA) or in a mixture of acetone and soy oil (HAO) was added to the artificial diet at a concentration of 200 μg/mL. The workers fed daily with the diet containing hydramethylnon showed higher mortality than the controls, especially when HAO was used. Moreover, light and electron microscopy revealed morphological alterations in the midgut and Malpighian tubules of workers treated with HA, whereas alterations of the post-pharyngeal glands were observed in the HAO-treated group. These results indicated that the presence of soy oil provided an alternate route for the ingestion of the formicide's active ingredient and corroborated previous studies that suggested a role for the post-pharyngeal glands in lipid metabolism. Our findings suggest that the oil may carry hydramethylnon to the gland lumen, resulting in lower quantity of the active ingredient in the intestinal lumen and Malpighian tubules that explains the lower degree of morphological alterations in these structures in the workers treated with HAO. These results may provide insight into the toxicological effects of hydramethylnon on leaf-cutting ants and the use of vegetable oil as an adjuvant in baits to control ants. © 2012 Elsevier Ltd.

Interações medicamentosas de fitoterápicos e fármacos: Hypericum perforatum e Piper methysticum

A utilização de produtos naturais na medicina popular é milenar e persiste até os dias atuais. Entretanto, a idéia de que estes produtos são isentos de toxicidade torna o uso de medicamentos fitoterápicos cada vez maior e indiscriminado. Este trabalho trata de uma revisão sobre as interações que podem ocorrer com a utilização concomitante de Hypericum perforatum L. (erva de são joão) e Piper methysticum F. (kava-kava) com fármacos, podendo levar a sérios efeitos tóxicos, incluindo a fatalidade.

Estudo clínico e laboratorial da intoxicação experimental por amitraz em gatos e comparação entre ioimbina e atipamezole como tratamento

Pós-graduação em Medicina Veterinária - FMVZ

2 '-Deoxyguanosine, 2 '-deoxycytidine, and 2 '-deoxyadenosine adducts resulting from the reaction of tetrahydrofuran with DNA bases

A recent study showed that tetrahydrofuran (THF), a widely used solvent, is carcinogenic in experimental animals. Despite its carcinogenic activity, there is a paucity of information regarding cellular toxicity, biomolecular damage, and genotoxicity induced by THF. We describe here the structural characterization of adducts produced by the reaction of oxidized THF with 2'-deoxyguanosine (dGuo-THF 1 and dGuo-THF 2), 2'-deoxyadenosine (dAdo-THF), and 2'-deoxycytidine (dCyd-THF). Adducts were isolated from in vitro reactions by reverse-phase HPLC and fully characterized on the basis of spectroscopic measurements. The stable derivatives obtained by the reduction of adducts with NaBH4 ( the case of dGuo-THF 1, dCyd-THF, and dAdo-THF) and the stable adduct dGuo-THF 2 were used as standards for optimization of chromatographic separations for adduct detection in DNA through HPLC/ESI/MSMS. Using this methodology, we successfully detected the four adducts in calf thymus DNA reacted with oxidized THF. The present study also provides evidence that rat liver microsomal monooxigenases oxidize THF to the reactive electrophilic compounds that are able to damage the DNA molecule, as indicated by a significant increase in adduct dGuo-THF 1 level when NADPH was added to the THF/ microsomes/dGuo incubation mixtures. Our data point to DNA-THF adducts as possible contributing factors to the toxicological effects of THF exposure.

Atividade in vivo de parasporina extraída de B. thuringiensis sobre o câncer colorretal murino (CT‐26)

Bacillus thuringiensis (Bt), is an environmental Gram-positive spore-forming bacterium that produces crystalline parasporal protein (Cry) during sporulation. The inclusions often exhibit strong and specific insecticidal activity, making Bt an agent for agricultural controlling insects pest, mites, protozoa and nematodes. Recent studies reported that some of these Crys do not show cytotoxicity against insects but they are capable to kill some human and animal cancer cells. These proteins were denominated parasporins (PS). However, antitumor activity of Bt parasporin on the development of murine colorectal cancer (CT-26), are not well studies and these are no reports on the in vivo effect of these proteins. Thus, the present study evaluated the in vitro and in vivo anti-tumoral activity of Bt parasporin against the murine colorectal cancer line CT-26. Therefore, Balb/c mice were s.c. inoculated with CT-26 cells and weekly treated with parasporin (i.p.) pre-activated by enzymatic digestion with trypsin or proteinase K. Our results have shown, for the first time, that despite the anti-tumor activity in vitro, parasporin crystals couldn’t combat tumor growth in vivo. Instead, this protein was highly toxic, affecting the liver and spleen, with possible effect on other organs, decreasing the survival of treated animals. The results indicate the need for studies to better detoxification or manipulation of parasporin for therapeutic use and new studies for analysis of toxicological effects of repetitive exposure of farmers to this toxin

Nanopartículas lipídicas como sistemas carreadores para ivermectina e metopreno visando aplicações em veterinária

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

Subacute toxicity assessment of diflubenzuron, an insect growth regulator, in adult male rats

Difubenzuron (DFB), an insecticide and acaricide insect growth regulator, can be used in agriculture against insect predators and in public health programs, to control insects and vectors, mainly Aedes aegypti larvae. Due to the lack of toxicological assessments of this compound, the objective of the present study was to evaluate the toxicological effects of subacute exposure to the DFB insecticide in adult male rats. Adult male rats were exposed (gavage) to 0, 2, 4, or 8 mg/kg of DFB for 28 days. No clinical signs of toxicity were observed in the DFB-treated animals of the experimental groups. However, there was an increase in serum levels of alanine aminotransferase in the group that received 8 mg/Kg/DFB/day and urea at doses of 4 and 8 mg/Kg/DFB/day, without altering other biochemical or hematological parameters. The subacute exposure to the lowest dose of DFB caused significant decrease in testis weight, daily sperm production, and in number of sperm in the epididymis in relation to the control group. However, no alterations were observed in the sperm morphology, testicular, epididymis, liver and kindney histology, or testosterone levels. These findings unveiled the hazardous effects of DFB on male reproduction after the subacute exposure and special attention should be addressed to the effects of low doses of this pesticide.

Toxicological and histopathological effects of boric acid on atta sexdens rubropilosa (Hymenoptera: Formicidae) workers

The current study compared the toxicity of different concentrations of boric acid in adult workers of Atta sexdens rubropilosa Forel (Hymenoptera: Formicidae), with toxicological bioassays, and examining the dose-dependent and time-dependent histopathological changes, of the midgut, Malpighian tubules, and postpharyngeal glands. Our results revealed the importance of conducting toxicological bioassays combined with morphological analyses of the organs of ants chronically exposed to insecticides used in commercial ant baits. In vitro bioassays showed that boric acid significantly decreases the survivorship of workers regardless of concentration, whereas the morphological data suggested progressive dose-dependent and time-dependent changes in the organs examined, which were evident in the midgut. The midgut is the first organ to be affected, followed by the postpharyngeal gland and Malpighian tubules. This sequence is in agreement with the absorption pathway of this chemical compound in the midgut, its transference to the hemolymph, possibly reaching the postpharyngeal glands, and excretion by the Malpighian tubules. These progressive changes might be due to the cumulative and delayed effect of boric acid. Our findings provide important information for the understanding of the action of boric acid in ant baits in direct and indirect target organs. © 2010 Entomological Society of America.

Effects of diuron on toxicological and hematological parameters and lymphohematopoietic organs in a rat chemical hepatocarcinogenesis model

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Anxiolytic and sedative effects of extracts and essential oil from Citrus aurantium L.

Citrus aurantium L. is commonly used as an alternative treatment for insomnia, anxiety and epilepsy. Essential oil from peel (EOP) and hydroethanolic (70% w/v) extract (HE) from leaves were obtained. Hexanic (HF), dichloromethanic (DF) and final aqueous (AF) fractions were obtained from HE by successive partitions. Swiss male mice (35-45 g) were treated orally with 0.5 or 1.0 g/kg of these preparations 30 min before the experiments for the evaluation of the sedative/hypnotic activity (sleeping time induced by sodium pentobarbital-SPB: 40 mg/kg, i.p.), anxiolytic activity (elevated plus maze-EPM) and anticonvulsant activity (induced by pentylenetetrazole-PTZ: 85 mg/kg, se or by maximal electroshock-MES: 50 mA, 0.11s, corneal). The results showed that EOP (0.5 g/kg) increased the latency period of tonic seizures in both convulsing experimental models. This effect was not dose-dependent. Treatment with 1.0 g/kg increased the sleeping time induced by barbiturates and the time spent in the open arms of the EPM. Specific tests indicated that the preparation, in both doses used, did not promote deficits in general activity or motor coordination. HF and DF fractions (1.0 g/kg) did not interfere in the epileptic seizures, but were able to enhance the sleeping time induced by barbiturates. The results obtained with EOP in the anxiety model, and with EOP, HF and DF in the sedation model, are in accord with the ethnopharmacological use of Citrus aurantium L., which could be useful in primary medical care, after toxicological investigation.

Antiulcerogenic and analgesic effects of Maytenus aquifolium, Sorocea bomplandii and Zolernia ilicifolia

Maytenus aquifolium (Celastraceae), Sorocea bomplandii (Moraceae) and Zolernia ilicifolia (Fabaceae) are native plants from the Tropical Atlantic Forest (Mata Atlantica, Brazil) known a 'espinheira-santa'. These plants are traditionally used as analgesic and antiulcerogenic medicine, with the same traditional uses of the true 'espinheira-santa' (Maytenus ilicifolia, Celastraceae), an efficient antiulcerogenic agent. Pharmacological and toxicological studies with these plants have not been carried out. The purpose in this study was to evaluate the efficacy (analgesic and antiulcerogenic activities), safety (acute toxicity) and quality (phytochemical profile) of these three plants. The analgesic effect was analyzed by writhing and tail flick tests, while anti Ulcerogenic effect was performed through ulcer induction by ethanol and indomethacin/bethanecol assays. LD., and acute toxic effects, as well as phytochemical profiles of all plants also were carried. Surprisingly, the three plants showed analgesic and antiulcerogenic effects at dose of 1000 mg/kg, v.o. Maytenus aquifolium lowering all ulcerogenic parameters (ethanol test), but increased the ulcerogenic effects in the indoniethacin/bethanecol test. Sorocea bomplandii produced antiulcerogenic effects in both experimental models used, while Zolernia ilicifolia showed significant effects only in indomethacin/bethanecol-induced gastric lesions. Pre-treatment with Zolernia ilicifolia induced someone toxic effects, A phytochemical profile for each plant species was determined and its main chemical classes of compounds were described. (C) 2001 Elsevier B.V. Ireland Ltd. All rights reserved.

Mouriri elliptica: Validation of gastroprotective, healing and anti-Helicobacter pylori effects

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

Maternal exposure to aqueous extract of Jacaranda decurrens: Effects on reproductive system in male rats

Context: Jacaranda decurrens subsp. symmetrifoliolata Farias & Proenca (Bignoniaceae) is a species widely used for their medicinal properties. At least to our known, no study has been conducted concerning its toxicological profile after gestational and lactational exposure.Objective: The present study was carried out to evaluate the effects of J. decurrens on development of the reproductive system in male rats.Materials and methods: Pregnant rats were treated daily (gavage) with 250 or 500 mg/kg/day of aqueous extract of J. decurrens or vehicle, from day 12 of pregnancy to day 21 of lactation.Results and Discussion: Both doses of J. decurrens significantly anticipated (p < 0.05) the age of testicular descent to the scrotum, a parameter indicative of puberty initiation. Furthermore, at puberty, there was a significant reduction (p < 0.05) in testicular and epididymis weights in the offspring exposed to the higher dose of extract, without effect on sperm production and the histology of reproductive organs. on the other hand, at adulthood, the reproductive parameters analyzed did not differ among groups.Conclusions: J. decurrens, in this experimental model, interfered with the initial development of the reproductive system, but without lasting effects on sperm production in adulthood.