Avaliação de atividade mutagênica de Astronium fraxinifolium, Astronium urundeuva e Serjania marginata Casar

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

In vitro antibacterial and chemical properties of essential oils including native plants from Brazil against pathogenic and resistant bacteria

The antimicrobials products from plants have increased in importance due to the therapeutic potential in the treatment of infectious diseases. Therefore, we aimed to examine the chemical characterisation (GC-MS) of essential oils (EO) from seven plants and measure antibacterial activities against bacterial strains isolated from clinical human specimens (methicillin-resistant Staphylococcus aureus (MRSA) and sensitive (MSSA), Escherichia coli, Pseudomonas aeruginosa, Salmonella Typhimurium) and foods (Salmonella Enteritidis). Assays were performed using the minimal inhibitory concentration (MIC and MIC90%) (mg/mL) by agar dilution and time kill curve methods (log CFU/mL) to aiming synergism between EO. EO chemical analysis showed a predominance of terpenes and its derivatives. The highest antibacterial activities were with Cinnamomun zeylanicum (0.25 mg/mL on almost bacteria tested) and Caryophyllus aronzaticus EO (2.40 mg/mL on Salmonella Enteritidis), and the lowest activity was with Eugenia uniflora (from 50.80 mg/mL against MSSA to 92.40 mg/mL against both Salmonella sources and P aeruginosa) EO. The time kill curve assays revealed the occurrence of bactericide synergism in combinations of C. aromaticus and C. zeylanicum with Rosmarinus. officinalis. Thus, the antibacterial activities of the EO were large and this can also be explained by complex chemical composition of the oils tested in this study and the synergistic effect of these EO, yet requires further investigation because these interactions between the various chemical compounds can increase or reduce (antagonism effect) the inhibitory effect of essential oils against bacterial strains.

Evaluation of mutagenicity and metabolism-mediated cytotoxicity of the naphthoquinone 5-methoxy-3,4-dehydroxanthomegnin from Paepalanthus latipes

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Mutagenicity and chemopreventive activities of Astronium species assessed by Ames test

In the neotropical savannah, Astronium species are used in popular medicine to treat allergies, inflammation, diarrhea and ulcers. Given that natural products are promising starting points for the discovery of novel potentially therapeutic agents, the aim of the present study was to investigate the mutagenic and antimutagenic activities of hydroalcoholic extracts of Astronium spp. The mutagenicity was determined by the Ames test on Salmonella typhimurium strains TA98, TA97a, TA100 and TA102. The antimutagenicity was tested against the direct-acting and indirect-acting mutagens. The results showed that none of the extracts induce any increase in the number of revertants, demonstrating the absence of mutagenic activity. On the other hand, the results on the antimutagenic potential showed a moderate inhibitory effect against NPD and a strong protective effect against B[a]P and AFB1. This study highlights the importance of screening species of Astronium for new medicinal compounds. The promising results obtained open up new avenues for further study and provide a better understanding the mechanisms by which these species act in protecting DNA from damage. However, further pharmacological and toxicological investigations of crude extracts of Astronium spp., as well as of its secondary metabolites, are necessary to determine the mechanism(s) of action to guarantee their safer and more effective application to human health.

Effect of biotransformation by liver S9 enzymes on the mutagenicity and cytotoxicity of melanin extracted from Aspergillus nidulans

A mutant that exhibited increased melanin pigment production was isolated from Aspergillus nidulans fungus. This pigment has aroused biotechnological interest due to its photoprotector and antioxidant properties. In a recent study, we showed that melanin from A. nidulans also inhibits NO and TNF-α production. The present study evaluates the mutagenicity and cytotoxicity of melanin extracted from A. nidulans after its exposure to liver S9 enzymes. The cytotoxicity of multiple concentrations of melanin (31.2-500 μg/mL) against the McCoy cell line was evaluated using the Neutral Red assay, after incubation for 24 h. Mutagenicity was assessed using the Ames test with the Salmonella typhimurium strains TA98, TA97a, TA100, and TA102 at concentrations ranging from 125 μg/plate to 1 mg/plate after incubation for 48 h. The cytotoxicity of A. nidulans melanin after incubation with S9 enzymes was less than (CI50 value= 413.4 ± 3.1 μg/mL) that of other toxins, such as cyclophosphamide (CI50 value = 15 ± 1.2 μg/mL), suggesting that even the metabolised pigment does not cause significant damage to cellular components at concentrations up to 100 μg/mL. In addition, melanin did not exhibit mutagenic properties against the TA 97a, TA 98, TA 100, or TA 102 strains of S. typhimurium, as shown by a mutagenic index (MI)  <2 in all assays. The significance of these results supports the use of melanin as a therapeutic reagent because it possesses low cytotoxicity and mutagenic potential, even when processed through an external metabolising system.

Antitumour and anti-inflammatory effects of Palladium (II) complexes on Ehrlich Tumour

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Atividade toxicogenética de corantes usados na formulação da tintura capilar preta, individuais e em associação, por meio de diferentes ensaios biológicos

Pós-graduação em Ciências Biológicas (Biologia Celular e Molecular) - IBRC

The effect of a Lactobacillus-based probiotic for the control of necrotic enteritis in broilers

Necrotic Enteritis (NE) caused by Clostridium perfringens (CP) in poultry is probably the most important bacterial disease in terms of economic implications. The disease is multi-factorial and is invariably associated with predisposing factors. The present study investigated the effect of a commercially available Lactobacillus-based probiotic (FM-B11) for the control of necrotic enteritis in broiler chickens. In experiment 1, one-day-of-hatch broiler chicks were randomly allocated to the following treatment groups: 1) Non-challenged (NC); 2) Challenged (C); 3) Challenged + probiotic (C+ FM-B11). Prior to placement, chicks in groups 2 and 3 received 0.25 mL of Salmonella typhimurium (ST) containing 105 cfu of viable cells by oral gavage. At 14, 15 and 16 days of age, all chicks in group 3 were treated with FM-B11 in the drinking water at a concentration of 106 cfu/ml. At 21d of age, all chicks in groups 2 and 3, were individually challenged with 5 × 104 sporulated oocysts of E. maxima by oral gavage. At 26d of age, all chicks in groups 2 and 3, were individually challenged with 108 cfu CP; body weight (BW) was recorded prior to challenge. The experiment was terminated at 29 days of age and the following parameters were evaluated: NE-associated mortality, CP lesion scores, CP concentrations in ileum, BW, and body weight gain (BWG). Chicks treated with FM-B11 had significantly (P < 0.05) higher body weight gain after challenge when compared to control challenge chickens. Total mortality was higher in the C group (48.8%) when compared to the C + FM-B11 (12.7%). Even though there was no significant (P > 0.05) difference in lesion score between C and C + FM-B11, group C + FM-B11 had significantly (P < 0.05) lower total number of cfu of CP recovered from the ileal mucosa and content samples when compared to group C. Experiment 2 was a unique and remarkable case report of a field outbreak of NE in a commercial broiler farm in Argentina. A reduction and control of the mortality associated with NE following 3 days of administration of FM-B11 was observed as compared with the control non treated house. These results imply that the commercially available Lactobacillus-based probiotic FM-B11 was able to reduce the severities of NE, as a secondary bacterial infection, in an experimental NE challenge model; as well as, in a commercial field outbreak of NE.

Avaliação toxicogenética e atividade antitumoral in vitro de complexos heterolépticos de Rutênio(II): Atividades citotóxicas, genotóxicas e interação com biomoléculas

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Avaliação da atividade mutagênica de complexos heterolépticos de Rutênio(II) com atividade anti - Mycobacterium tuberculosis

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

Utilização de métodos não invasivos para avaliação da segurança de fitocosmético contendo extrato de goiaba para aplicação tópica

É bem conhecido que uma das consequências causada pela radiação ultravioleta gerada pela luz solar é o fotoenvelhecimento e o desenvolvimento de cânceres cutâneos por meio da ação dos radicais livres gerados sobre a pele. A utilização de uma formulação de uso tópico pela população que auxilie na prevenção do envelhecimento precoce e de doenças causadas pelos radicais livres à pele humana seria de grande valia, trazendo benefícios estéticos, que influenciariam diretamente a saúde psicológica do usuário e preveniriam a fotocarcinogênese. Este fato se torna ainda mais importante em um país tropical como o Brasil, onde a incidência de radiação UV é bastante elevada, assim como o desenvolvimento de cânceres de pele na população. Devido às evidências encontradas em estudos prévios que indicam o potencial antioxidante da goiaba, esta pesquisa teve por objetivo desenvolver estudos para avaliação da segurança in vitro e in vivo de fitocosmético antioxidante através da avaliação do potencial mutagênico em cepas de Salmonella typhimurium, além de avaliar seu potencial irritativo e alergênico na pele de voluntários saudáveis. Para isto foi utilizado o método de Ames, amplamente utilizado para esta finalidade, em que o extrato de Psidium guajava L. foi considerado não mutagênico para todas as cepas avaliadas e foi possível constatar que o extrato promoveu efeito antimutagênico moderado apenas na cepa TA 100. No ensaio para avaliação do potencial irritativo e alergênico realizado in vivo, foi comprovada a ausência de potencial irritante e alergênico de fitocosmético. Desta forma, os estudos realizados indicam a segurança em utilizar o extrato de Psidium guajava L. como antioxidante de uso tópico.

Requirement for cobalamin by Salmonella enterica serovars Typhimurium, Pullorum, Gallinarum and Enteritidis during infection in chickens

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

Comparação de Meios de Enriquecimento e de Plaqueamento Utilizados na Pesquisa de Salmonella em Carcaças de Frango e Fezes de Aves

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

Avaliação in vitro da atividade inibitória de Lactobacillus spp., isolados do inglúvio e cecos de aves sobre Salmonella

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

STUDIES ON THE USE OF A FORMIC-ACID PROPIONIC-ACID MIXTURE (BIO-ADD(TM)) TO CONTROL EXPERIMENTAL SALMONELLA INFECTION IN BROILER-CHICKENS

Experiments were carried out on the antibacterial effects of a commercial formic acid-propionic acid mixture (Bio-add(TM)) against different Salmonella serptj pes. The preparation exerted a strong antibacterial effect on S. typhimurium strain F98 in artificially contaminated feed. After 28 days storage, the bactericidal effect was still considerable. When chickens were reared on feed that had been treated with Bio-add(TM) and artificially contaminated with different serotypes, S. enteritidis, S. typhimurium and S. agona were not isolated from the caecal contents, but S. infantis was. No organisms of this strain were isolated when a lower feed-contamination rate of bacteria was used.