Atividade antibacteriana do extrato hidroalcoólico de Punica granatum Linn. sobre Staphylococcus spp. isolados de leite bovino / Antibacterial activity of the hydroalcoholic extract of Punica granatum Linn. on Staphylococcus spp. isolated from bovine milk

Mastite bovina é caraterizada por inflamação da glândula mamária, geralmente em resposta à infecção bacteriana, compromete quali-quantitativamente a produção leiteira. Este estudo objetivou verificar a atividade antibacteriana in vitro do extrato hidroalcoólico da casca da romã sobre bactérias isoladas de leite bovino. As colônias de Staphylococcus spp. foram ressuspendidas a escala 6 de MacFarland e ajustada a sua concentração por espectrofotometria UV visível na concentração de 10 mL-1. Os extratos foram avaliados em quintuplicata, em sete concentrações: de 4mg mL-1 até 0,0625 mg.mL-1. A sensibilidade dos isolados microbianos foi determinada utilizando o teste de difusão em disco e os resultados que apresentaram zonas de inibição correspondentes a valores a partir de 15 mm, foram considerados sensíveis. Os resultados foram avaliados pelo método ANOVA, teste de Tukey 5 por cento, utilizando o SISVAR 5.3 -DEX/UFLA. Adicionalmente o extrato foi avaliado quanto à atividade antioxidante, teores de fenóis e flavonoides totais. Para tanto o extrato foi diluído em sete concentrações: de 25 a 1000µg.mL-1, e avaliado em triplicata. O crescimento bacteriano foi inibido a partir da concentração de 4mg.mL-1 e a ação antioxidante foi verificada a partir de 50µg.mL-1, com valores correspondentes a 4.62 por cento, atingindo platô de 64,90 por cento na concentração de 500µg.mL-1. Na avaliação da atividade captadora de radicais, empregando o radical livre DPPH, o extrato demonstrou atividade antioxidante (IC50 por cento= 378,80µg/mL). Porém, não foi possível correlacionar a atividade antioxidante aos teores de fenóis e flavonoides. Talvez a presença de outras substâncias alcaloides e taninos presentes no extrato, possam ter sido as responsáveis pela atividade antioxidante encontrada. Conclui-se que o extrato hidroalcoólico de Punica granatum Linn. apresenta atividade antimicrobiana contra Staphylococcus spp., demonstrando potencial benefício para o controle da mastite bovina.

Bovine mastitis is characterized by inflammation of the mammary gland, usually in response to bacterial infection, affecting qualitatively and quantitatively milk production. This study aimed to determine the antibacterial activity in vitro of the hydroalcoholic extract of the bark of the pomegranate on bacteria isolated from bovine milk. The colonies of Staphylococcus spp. were resuspended in 6 MacFarland scale and adjusted its concentration by UV visible spectrophotometry at a concentration of 10(6)ml-1. The extracts were evaluated in quintuplicate in seven concentrations: from 4 up to 0.0625mg.mL-1. The sensitivity of microbial isolates was determined using the disk diffusion and the results that showed inhibition halos corresponding to values from 15mm were considered susceptible. The results were evaluated by ANOVA, Tukey test 5 percent using the SISVAR 5.3-DEX/UFLA. Additionally the extract was assessed as for the antioxidant activity, content of phenols and total flavonoids. The extract was diluted into seven concentrations: 25-1.000µg.mL-1, and evaluated in triplicate. The bacterial growth was inhibited starting from the concentration of 4 mg.mL-1 and antioxidant activity was observed from 50µg.mL-1, with values corresponding to 4.62 percent reaching the plateau of 64.90 percent at a concentration of 500µg.mL-1. In evaluating the radical scavenging activity, using the free radical DPPH, the extract demonstrated antioxidant activity (IC50 percent= 378.80µg/mL). However it has not been possible to correlate the antioxidant activity with the levels of phenols and flavonoids. Perhaps the presence of other substances alkaloids and tannins present in the extracts may have been responsible for the antioxidant activity found. It was concluded that the hydroalcoholic extract of Punica granatum Linn. has antimicrobial activity against Staphylococcus spp., demonstrating potential benefit for the control of bovine mastitis.

Avaliação do potencial genotóxico do extrato bruto de Pyrostegia venusta (Ker Gawl. ) Miers, Bignoneaceae, em medula óssea de camundongos / The Evaluation of the genotoxic potency of the Pyrostegia venusta (Ker Gawl. ) Miers, Bignoneaceae, crude extract on bone marrow of mice

Pyrostegia venusta (Ker Gawl.) Miers, Bignoneaceae, é utilizada no tratamento de vitiligo e de outras doenças, mas seus efeitos genotóxicos não são conhecidos. Neste sentido, o presente estudo teve por objetivo avaliar o efeito genotóxico de extratos de P. venusta em camundongos utilizando os Testes de Micronúcleo (MN) e o de Aberração Cromossômica (AC). O vegetal foi coletado, selecionado, seco, triturado e extraído com etanol. Camundongos de 40 g foram divididos em grupos experimentais e controles. Os grupos experimentais receberam concentrações crescentes do extrato (50, 100 e 200 mg/kg por peso corporal), por v.o. O grupo controle negativo (CN) recebeu água. O grupo controle positivo (CP) recebeu Ciclofosfamida® por v.i. Realizou-se o sacrifício, retirada da medula óssea, homogeneização e preparação das lâminas. As freqüências de eritrócitos policromáticos micronucleados (EPCMN) foram: CN = 0,35±0,09; CP = 2,87±1,78; 50 = 0,09±0,04; 100 = 0,16±0,08 e 200 = 0,10±0,03. O teste de AC apresentou as seguintes freqüências: CN = 0,12±1,87; CP = 0,62±5,61; 50 = 0,12±1,58; 100 = 0,072±0,54 e 200 = 0,124±1,64. As freqüências de EPCMN dos grupos experimentais foram significantemente inferiores quando comparadas com as dos controles. A freqüência de cromossomos aberrantes não teve diferença significativa se comparada com o CN, mas foi estatisticamente menor que a do CP. P.venusta não apresentou atividade genotóxica.

Pyrostegia venusta (Ker Gawl.) Miers, Bignoneaceae, is used in the treatment of vitiligo and other diseases, but its genotoxic effects are unknown. In this way, this study aimed to evaluate the genotoxic effect of extracts of P. venusta in mice using the micronucleus (MN) and chromosome aberration tests (CA). The plant was collected, selected, dried, pounded and extracted with ethanol. Mice weighing 40 g were divided in experimental and control groups. The experimental groups received different concentrations (50, 100, and 200 mg/kg body weight), by oral gavage. The negative control group (NC) received water. The positive control group (PC) received Ciclophosphamide® by v.i. It was performed the sacrifice, removal of bone marrow, homogenization and slides preparation. Frequency of micronucleated polychromatic erythrocytes (MNPCE) was: NC = 0.35±1.87; PC = 2.87±9.02; 50 = 0.09±0.83; 100 = 0.16±0.10 e 200 = 0.10±0.71. The CA test showed the frequency: NC = 0.12±1.87; PC = 0.62±5.61; 50 = 0.12±1.58; 100 = 0.072±0.54 e 200 = 0.124±1.64. The frequency of MNPCE of experimental controls was significantly lower when compared with NC, but it was statistically lower than PC's frequency. P.venusta didn't show genotoxicity activity.

Modulatory effects of Tabebuia impetiginosa (Lamiales, Bignoniaceae) on doxorubicin-induced somatic mutation and recombination in Drosophila melanogaster

The wing Somatic Mutation and Recombination Test (SMART) in D. melanogaster was used to study genotoxicity of the medicinal plant Tabebuia impetiginosa. Lapachol (naphthoquinone) and β-lapachone (quinone) are the two main chemical constituents of T. impetiginosa. These compounds have several biological properties. They induce apoptosis by generating oxygen-reactive species, thereby inhibiting topoisomerases (I and II) or inducing other enzymes dependent on NAD(P)H:quinone oxidoreductase 1, thus affecting cell cycle checkpoints. The SMART was used in the standard (ST) version, which has normal levels of cytochrome P450 (CYP) enzymes, to check the direct action of this compound, and in the high bioactivation (HB) version, which has a high constitutive level of CYP enzymes, to check for indirect action in three different T. impetiginosa concentrations (10 percent, 20 percent or 40 percent w/w). It was observed that T. impetiginosa alone did not modify the spontaneous frequencies of mutant spots in either cross. The negative results observed prompted us to study this phytotherapeuticum in association with the reference mutagen doxorubicin (DXR). In co-treated series, T. impetiginosa was toxic in both crosses at higher concentration, whereas in the HB cross, it induced a considerable potentiating effect (from ~24.0 to ~95.0 percent) on DXR genotoxity. Therefore, further research is needed to determine the possible risks associated with the exposure of living organisms to this complex mixture.