Viviane Cristina Sebben

Screening for in vivo (anti)estrogenic activity of ephedrine and p-synephrine and their natural sources Ephedra sinica Stapf. (Ephedraceae) and Citrus aurantium L. (Rutaceae) in rats

Formulations containing Ephedra sinica Stapf. (Ephedraceae) and Citrus aurantium L. (Rutaceae) are consumed worldwide for body weight control. Considering the related adverse effects and the risk potential, the aim of this study is to evaluate the effects of the thermogenic compounds ephedrine, p-sinephrine, E. sinica and C. aurantium in the female reproductive system through the uterotrophic assay in immature female rats. The animals (n = 6–7) received E. sinica 85.5 and 855.0 mg/kg/day, C. aurantium 25.0 and 50.0 mg/kg/day, ephedrine 5.0 mg/kg/day and p-synephrine 50.0 mg/kg/day for three consecutive days by oral gavage. For detection of antiestrogenicity, tamoxifen 20.0 mg/kg/day, E. sinica 855.0 mg/kg/day, C. aurantium 50.0 mg/kg/day, ephedrine 5.0 mg/kg/day and p-synephrine 50.0 mg/kg/day were administered to estrogen-treated females. Macroscopical alterations were evaluated in liver, kidneys, adrenals and uterus. All analyzed substances showed an antiestrogenic potential, but only ephedrine at 0.5 mg/kg/day presented a significative antiestrogenic effect (P < 0.01). Adrenals relative mass were reduced (P < 0.01) in all tested compounds when compared to the control, which seems to be related to the alfa-1-adrenoceptor agonist activity, which promote a vasoconstriction and reduction of the liquid in the organ. The endocrine system is highly complex and there are a number of ways in which a chemical may interfere with it, other in vivo and in vitro assays are being necessary to support this mechanism of action.

Validação de metodologia analítica e estudo de estabilidade para quantificação sérica de paracetamol

INTRODUCAO E OBJETIVO: Paracetamol ou acetaminofeno e atualmente um dos analgesicos-antipireticos mais utilizados, principalmente em criancas. Porem o facil acesso ao medicamento e o desconhecimento da populacao sobre seus efeitos nocivos tem aumentado muito o numero de intoxicacoes por esse medicamento. A analise da concentracao serica de paracetamol confirma o diagnostico. O resultado nao so tem valor de certeza diagnostica como tambem avalia o risco de hepatotoxicidade, indicando uso ou nao do antidoto especifico n-acetilcisteina. O objetivo deste trabalho foi propor um metodo analitico para quantificacao serica do paracetamol por espectrofotometria visivel em 430 nm. MATERIAIS E METODOS: Apos desproteinizacao da amostra, acetaminofeno (n-acetil-p-aminofenol) reage com nitrito de sodio, formando 2,4-nitro-4-acetaminofenol, que assume coloracao amarela em meio alcalino. As figuras de merito linearidade, precisao, exatidao, robustez, recuperacao, limites de deteccao e qualificacao foram avaliadas segundo criterios preconizados pelo International Conference on Harmonisation (ICH) e pela Agencia Nacional de Vigilância Sanitaria (ANVISA). O estudo de estabilidade foi realizado apos ciclos de congelamento/descongelamento, curta duracao, longa duracao sob refrigeracao e em freezer. RESULTADOS: O metodo se mostrou linear de 20 a 300 mg/l. Os limites de deteccao e quantificacao foram de respectivamente 3,6 mg/l e 20 mg/l. CONCLUSAO: O metodo se mostrou preciso, exato e robusto e apresentou boa recuperacao. As amostras-controle foram estaveis nas condicoes testadas. O metodo desenvolvido demonstrou possuir todos os parâmetros necessarios para ser aplicado na quantificacao de paracetamol em amostras de plasma ou soro humano para analise de emergencia. Alem disso, e uma tecnica simples, de rapida execucao e baixo custo.

Investigação da presença de efedrinas em Ephedra tweediana Fisch & C.A. Meyer e em E. triandra Tul. (Ephedraceae) coletadas em Porto Alegre/RS

Samples of Ephedra tweediana, collected from native populations occurring in the Reserva Biologica do Lami Jose Lutzenberger (Porto Alegre, RS, Brazil), and from cultivated plants of Ephedra triandra were submitted to extraction with acetone, derivatized with cyclohexanone and analyzed by GC/MS. In order to verify the efficiency of the methodology, besides Ephedra tweediana and E. triandra, samples of five commercial Ephedra extracts were analyzed, from distinct origins, get up from local drugstores. The results showed the absence of ephedrines in Ephedra tweediana and E. triandra, and the presence of ephedrine and/or pseudoephedrine in commercial samples.

Hearing loss in shoemakers exposed to noise and solvent in Porto Alegre, Brazil

Clinical and experimental studies indicate a possible harmful effect of chemicals, especially organic solvents, on the hearing system. In combined exposure to noise and solvents, very common in industry, it is most likely that a synergetic action of these factors enhances the traumatizing effect of exposure to noise. The aim of this study was to access the incidence and the risk of hearing impairment in 80 shoemakers. In this work we studied the effects of occupational exposure to solvent and noise in the hearing of workers of a factory in Porto Alegre, Brazil. In the studied group we analyzed solvents concentration in the air, biological marker for toluene in urine (hippuric acid), and levels of environmental noises. We analyze too the flow sheet of industrial production. The analysis of these results showed the bilateral hearing loss of 22.45%, and 18.37% in unilateral loss, in the workers of occupational exposure to toluene and noise, with levels allowed by the Brazilian legislation. The findings sugge...