Ensaios biológicos para avaliação de segurança de produtos cosméticos

Despite efforts to the contrary, some cosmetic products can cause undesirable side effects in the users. These may often be due to individual factors or inappropriate use of the product. Thus, biological assays to assess the safety of a new cosmetic must precede its being placed on the market. Historically, these tests have always been carried out in vivo, in animals, since such tests can be used to evaluate many of the potential risks, such as irritation, allergy or systemic effects; but, recently, some research centers have been adopting in vitro alternatives, in order to replace the animal tests. This review emphasizes the need to employ biological assays to test the safety of cosmetic products, and reviews the main in vivo and in vitro tests used, focusing on the need to develop and use alternatives to the in vivo assays of product safety, so as to offer the consumers the maximum safety with the least possible risk, while ensuring the best conditions of use of the product.

Interaction of Bacillus thuringiensis Cry1 and Vip3A proteins with Spodoptera frugiperda midgut binding sites

Vip3Aa, Vip3Af, Cry1Ab, and Cry1Fa were tested for their toxicities and binding interactions. Vip3A proteins were more toxic than Cry1 proteins. Binding assays showed independent specific binding sites for Cry1 and Vip3A proteins. Cry1Ab and Cry1Fa competed for the same binding sites, whereas Vip3Aa competed for those of Vip3Af. Copyright © 2009, American Society for Microbiology. All Rights Reserved.

Isolation of toxoplasma gondii from goats from Brazil

Goats are economically important in many countries, and little is known of caprine toxoplasmosis in Brazil. Antibodies to Toxoplasma gondii were assayed in the sera of 143 goats from 3 Brazilian states, using modified agglutination test (MAT titer ≥1:25); 46 (32.2%) tested positive. Samples of brain, heart, diaphragm, and masseter of seropositive animals were pooled, digested in pepsin, and bioassayed in mice. Viable T. gondii specimens were isolated from tissue homogenates of 12 goats; the isolates were designated TgGtBr1-12. Ten of the 12 isolates killed 100 of infected mice, indicating that goats can harbor mouse-virulent T. gondii and, hence, can serve as a source of infection for humans. © 2009 American Society of Parasitologists.

Produção de agaricus blazei ss. Heinemann (A. brasiliensis) em função de diferentes camadas de cobertura e substratos de cultivo

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Resposta plasmática de glicose e insulina em eqüinos alimentados com diferentes fontes de amido

This study was aimed to measure the plasmatic response of glucose and insulin of horses fed diets containing different starch sources, like corn, oat, sorghum and a mix of corn and oat in equal parts. Four standarbred gelding 36 month old an weighing average of 350 kg were used in a Latin Square 4 x 4 (four animals, four treatments and four period) trial design. No statistical differences were observed in plasmatic glucose levels either before or after ingestion between treatments. Maximum plasmatic level of glucose was observed in all diets two and a half hours post ingestion. Insulin plasmatic level was significantly lower before ingestion in horses treated with the mixed corn and oat diet, when compared with the other treatments. In the other hand, the insulin plasmatic level in horses fed corn-formulated diet was statistically higher than the others treatments at three hours and a half after ingestion. Diets containing different sources of starch had no effect in time neither quantity of glucose absorbed in small intestine. Variation observed in insulin plasmatic levels indicate that a proper feeding can have a regulatory effect of this hormone, avoiding undesirable's behaviors.

Estudo fitoquímico preliminar e bioensaio toxicológico frente a larvas de Artemia salina Leach. de extrato obtido de frutos de Solanum lycocarpum A. St.-Hill (Solanaceae)

The phytochemical profile of ethanolic extract of Solanum lycocarpum fruits was analyzed and preliminary toxicity tests were performed against brine shrimp larvae. The extract was subjected to preliminary phytochemical analysis to identify the main classes of secondary metabolites and tested against the larvae of A. salina to obtain the median lethal concentrations (LC50%). The phytochemical tests showed the presence of phenols, tannins, saponins, alkaloids and free steroids. The extract was fractionated with various solvents for toxicity testing against the larvae and the hydroalcoholic fraction showed considerable cytotoxicity (CL50% = 285.546 g/mL).

Human interferon B1 ser17: Coding DNA synthesis, expression, purification and characterization of bioactive recombinant protein

A protocol to produce large amounts of bioactive homogeneous human interferon β1 expressed in Escherichia coli was developed. Human interferon β1 ser17 gene was constructed, cloned and subcloned, and the recombinant protein expressed in E. coli cells. Solubilization of recombinant human interferon β1 ser17 (rhIFN-β1 ser17) was accomplished by employing a brief shift to high alkaline pH in the presence of non-ionic detergent. The recombinant protein was purifi ed by three chromatographic steps. N-terminal amino acid sequencing and mass spectrometry analysis provided experimental evidence for the identity of the recombinant protein. Reverse phase liquid chromatography demonstrated that the content of deamidates and sulphoxides was similar to a commercial standard. Size exclusion chromatography demonstrated the absence of high molecular mass aggregates and dimers. The protocol represents an effi cient and high-yield method to obtain bioactive homogeneous monomeric rhIFN-β1 ser17 protein. It may thus represent an important step towards scaling up for rhIFN-β1 ser17 large-scale production. © 2010 Villela AD, et al.

Determination of the quality index of a Paleudult under sunflower culture and different management systems

Soil is an essential resource for life and its properties are susceptible to be modified by tillage systems. The impact of management practices on soil functions can be assessed through a soil quality index. It is interesting to assess soil quality in different soil types. Therefore, the aim of this study was to determine the soil quality index of a Paleudult under different management conditions and sunflower culture. The experiment was carried out in Botucatu (SP, Brazil), in an 11-year non-tilled area used for growing soybean and maize during summer and black oat or triticale in winter. Four management systems were considered: no-tillage with a hoe planter (NTh), no-tillage with a double-disk planter (NTd), reduced tillage (RT) and conventional tillage (CT). Soil samples were taken from the planting lines at harvest time. To determine the soil quality indices, following the methodology proposed by Karlen and Stott (1994), three main soil functions were assessed: soil capacity for root development, water storage capacity of the soil and nutrient supply capacity of the soil. The studied Paleudult was considered a soil with good quality under all the observed management systems. However, the soil quality indices varied between treatments being 0.64, 0.68, 0.86 and 0.79 under NTh, NTd, RT and CT, respectively. Physical attributes such as resistance to penetration and macroporosity increased the soil quality index in RT and CT compared to NTh and NTd. The soil quality indices obtained suggested that the evaluated soil is adequate for sunflower production under our study conditions. In view of the SQI values, RT is the most suitable management for this site since it preserves soil quality and provides an acceptable sunflower yield. © 2011 Elsevier B.V.

Carbono orgânico e carbono residual do solo em sistema de plantio direto, submetido a diferentes manejos

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Development and validation of a microbiological agar assay for determination of orbifloxacin in pharmaceutical preparations

Orbifloxacin is a fluoroquinolone with broad-spectrum antimicrobial activity, and belongs to the third generation of quinolones. Regarding the quality control of medicines, a validated microbiological assay for determination of orbifloxacin in pharmaceutical formulations has not as yet been reported. For this purpose, this paper reports the development and validation of a simple, sensitive, accurate and reproducible agar diffusion method to quantify orbifloxacin in tablet formulations. The assay is based on the inhibitory effect of orbifloxacin upon the strain of Staphylococcus aureus ATCC 25923 used as test microorganism. The results were treated statistically by analysis of variance and were found to be linear (r = 0.9992) in the selected range of 16.0-64.0 μg/mL, precise with relative standard deviation (RSD) of repeatability intraday = 2.88%, intermediate precision RSD = 3.33%, and accurate (100.31%). The results demonstrated the validity of the proposed bioassay, which allows reliable orbifloxacin quantitation in pharmaceutical samples and therefore can be used as a useful alternative methodology for the routine quality control of this medicine. © 2011 by the authors; licensee MDPI, Basel, Switzerland.

Efeito da antecipação da adubação nitrogenada na cultura do milho em sistema plantio direto

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Evaluation of the toxicity of Virola sebifera crude extracts, fractions and isolated compounds on the nest of leaf-cutting ants

The phytochemical study of Virola sebifera leaves led to the isolation of three lignans: (+)-sesamin, (-)-hinokinin, and (-)-kusunokinin and three flavonoids: quercetin-3-O - L-rhamnoside, quercetin-3-O - D-glucoside, and quercetin-3-methoxy-7-O - D-glucoside by using techniques as high-speed counter-current chromatography and high-performance liquid chromatography. The crude extracts, fractions, and isolated compounds were evaluated for their insecticidal and fungicidal potential against Atta sexdens rubropilosa and its symbiotic fungus Leucoagaricus gongylophorus. The bioassay results showed a high insecticidal activity for the methanol crude extract of the leaves of V. sebifera and its n-hexane, dichloromethane and ethyl acetate fractions. The fungicidal bioassay revealed high toxicity of the lignans against L. gongylophorus. © 2012 Keylla Utherdyany Bicalho et al.

Plantas de cobertura e adubação nitrogenada na cultura do algodoeiro

The fiber quality, productivity and favorable climate are considered key points for the development of the cotton crop in the Brazilian Cerrado. This study aimed to evaluate the effect of cover crops and N application in presowing on the cotton crop growth and yield. The experimental design was randomized blocks, consisting of a - three cover crops (radish, white oat and black oat) implanted during the winter period, b - four nitrogen levels (0, 30, 60 and 90 kg ha-1 of N) applied to the millet residues and before cotton sowing. In April 2008, evaluations were realized of plant development and also harvesting was performed of experimental plots of cotton plants. The results showed that the radish provides increased length of branches and cotton bolls of cotton crop, without yield increase, and the use of increasing doses of N up to 90 kg ha-1 decreased the amount of carimã per plant, increasing the number of reproductive branches and cotton yield.

Validation of microbiological assay for determination of cefuroxime in injectable preparations

The validation of a microbiological assay, applying agar diffusion method for determination of the active of cefuroxime in power for injection, is described. Using a strain of Micrococcus luteus ATCC 9341 as the test organism, cefuroxime was measured in concentrations ranging from 30.0 to 120.0 μg/mL. The method validation showed that it is linear (r = 0.9999), precise (relative standard deviation = 0.37%) and accurate (it measured the added quantities). Microbiological assay is satisfactory for quantitation of cefuroxime in powder for injection and the validity of the proposed bioassay, which is a simple and a useful alternative methodology for cefuroxime determination in routine quality control.

Development and validation of a successful microbiological agar assay for determination of ceftriaxone sodium in powder for injectable solution

Ceftriaxone sodium is a cephalosporin with broad-spectrum antimicrobial activity and belongs to the third generation of cephalosporins. Regarding the quality control of medicines, a validated microbiological assay for the determination of ceftriaxone sodium in powder for injectable solution has not been reported yet. This paper reports the development and validation of a simple, accurate and reproducible agar diffusion method to quantify ceftriaxone sodium in powder for injectable solution. The assay is based on the inhibitory effect of ceftriaxone sodium on the strain of Bacillus subtilis ATCC 9371 IAL 1027 used as test microorganism. The results were treated statistically by analysis of variance and were found to be linear (r = 0.999) in the selected range of 15.0-60.0 μg/mL, precise with a relative standard deviation (RSD) of repeatability intraday = 1.40%, accurate (100.46%) and robust with a RSD lower than 1.28%. The results demonstrated the validity of the proposed bioassay, which allows reliable ceftriaxone sodium quantitation in pharmaceutical samples and therefore can be used as a useful alternative methodology for the routine quality control of this medicine. © 2012 by the authors; licensee MDPI, Basel, Switzerland.