Antiproliferative and photoprotective activities of the extracts and compounds from Calea fruticosa

In this paper, we complement our previous study on the antiproliferative activity of Calea fruticosa (Asteraceae) by isolating the compounds apigenin-4',7-dimethyl ether (1), budlein A (2), quercetin (3), and cichoriin (4) from the plant's aerial parts. The antiproliferative activity of these compounds was evaluated by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method against human tumor cell lines. Compound 3 displayed moderate antiproliferative activity in three cell lines (HCT-116, PC-3, and SF-295, with cell growth inhibition values of 72.97, 74.55, and 68.94%) and high antiproliferative activity (90.86%) in the HL-60 cell line. The in vitro sun protection factor (SPF) of the extracts and compound 4, with and without sunscreen, was determined by a spectrophotometric method. The ethanol extract exhibited the highest SPF (9.67) at a concentration of 0.100 mg/mL, while compound 4, isolated from this extract, showed a SPF of 13.79 at the same concentration. A relative increased efficacy of SPF was observed for the extracts and compound 4 when sunscreen was also used. Compound 4 has not been reported previously from any species within the genus Calea. Compounds 1-4 were obtained from this species for the first time.

Molecular identification of Lactobacillus spp. associated with puba, a Brazilian fermented cassava food

Puba or carimã is a Brazilian staple food obtained by spontaneous submerged fermentation of cassava roots. A total of 116 lactobacilli and three cocci isolates from 20 commercial puba samples were recovered on de Man, Rogosa and Sharpe agar (MRS); they were characterized for their antagonistic activity against foodborne pathogens and identified taxonomically by classical and molecular methods. In all samples, lactic acid bacteria were recovered as the dominant microbiota (7.86 ± 0.41 log10 CFU/g). 16S-23S rRNA ARDRA pattern assigned 116 isolates to the Lactobacillus genus, represented by the species Lactobacillus fermentum (59 isolates), Lactobacillus delbrueckii (18 isolates), Lactobacillus casei (9 isolates), Lactobacillus reuteri (6 isolates), Lactobacillus brevis (3 isolates), Lactobacillus gasseri (2 isolates), Lactobacillus nagelii (1 isolate), and Lactobacillus plantarum group (18 isolates). recA gene-multiplex PCR analysis revealed that L. plantarum group isolates belonged to Lactobacillus plantarum (15 isolates) and Lactobacillus paraplantarum (3 isolates). Genomic diversity was investigated by molecular typing with rep (repetitive sequence)-based PCR using the primer ERIC2 (enterobacterial repetitive intergenic consensus). The Lactobacillus isolates exhibited genetic heterogeneity and species-specific fingerprint patterns. All the isolates showed antagonistic activity against the foodborne pathogenic bacteria tested. This antibacterial effect was attributed to acid production, except in the cases of three isolates that apparently produced bacteriocin-like inhibitory substances. This study provides the first insight into the genetic diversity of Lactobacillus spp. of puba.

Efeito da administração do Allium sativum sobre as alterações cardiovasculares de ratos Wistar com infarto do miocárdio. / Effects of consumption of Allium sativum on the cardiovascular abnormalities observed in Wistar rats following cardiac infarction.

O alho (Allium sativum) apresenta várias ações benéficas ao sistema circulatório, tais como diminuição dos níveis de colesterol total, LDL-colesterol e da pressão arterial, além de efeito antioxidante. O objetivo deste estudo foi avaliar o efeito da administração do Allium sativum sobre as alterações da hemodinâmica cardiovascular e estruturais macroscópicas do coração de animais com infarto induzido experimentalmente. Ratos Wistar foram tratados, previamente e após indução do infarto, com homogeneizado de alho na dose de 125mg/Kg/dia durante 21 dias, por via oral (uma semana antes e duas depois do procedimento de infarto). Os grupos controle passaram por cirurgia fictícia (SHAM). Os animais foram divididos em grupos controles e infartados com (SHAMT, INFT; respectivamente) ou sem (SHAM, INF; respectivamente) tratamento com alho. Houve redução da hipertrofia do ventrículo direito (INF=0,75±0,05 vs. INFT=0,61±0,03 mg/Kg; p<0,01), da área de infarto (INF=29,7±4,8% vs. INFT=20,4±1,4%; p<0,05) e regularização dos níveis de pressão arterial sistólica (PAS; INF=100±8 vs. INFT=127±7 mmHg; p<0,05) e média (PAM; INF=94±4 vs. INFT=110±6 mmHg; p<0,01) dos animais INFT comparados com os INF. Houve um menor número de animais mortos após o procedimento de infarto no grupo INFT em relação ao grupo INF (20%, n=2; 45,5%, n=5; respectivamente). Esses achados indicam que o alho tem um importante papel na prevenção e no controle de alterações cardiovasculares, uma vez que houve redução do número de mortes pós-infarto e melhor perfil cardiovascular dos animais INFT.

Garlic (Allium sativum) has several beneficial effects on the cardiovascular system, such as reductions of the levels of total cholesterol, LDL-cholesterol and blood pressure, besides acting as an antioxidant. The aim of this study was to assess the effects of administering Allium sativum on changes in the cardiovascular hemodynamics and macroscopic structure that occur in the hearts of animals with experimentally induced cardiac infarction. Male Wistar rats were treated with homogenized garlic at a dose of 125mg/kg b.w./day for 21 days, given orally for one week before and two weeks after the procedure to induce myocardial infarction. The control group was subjected to a fictitious surgery (SHAM). The animals were divided into control and infarcted groups, treated (SHAMT, INFT) or untreated (SHAM, INF) with garlic. There were reductions in right ventricular hypertrophy (INF=0.75±0.05 vs. INFT=0.61±0.03 mg.kg-1; p<0.01) and infarcted area (INF=29.7±4.8 % vs. INFT=20.4±1.4 %; p<0.05) and regularization of the levels of systolic (SAP; INF=100±8 vs. INFT=127±7 mm Hg; p<0.05) and mean arterial pressure (MAP; INF=94±4 vs. INFT=110±6 mm Hg; p<0.01) in the INFT animals, compared to the INF group. Fewer animals died after the cardiac infarction procedure in the group INFT than in INF (20%, n=2; 45.5%, n=5; respectively). These findings suggest that garlic can have an important role in the prevention and control of cardiovascular abnormalities, since there was a reduction in the number of post-infarction deaths and an improvement of the cardiovascular profile in the INFT animals.

Multiple antimicrobial resistance in Enterobacteriaceae isolates from pristine freshwater

A freshwater enterobacterial population (N = 111) was studied for antimicrobial and mercury resistance patterns, and for its possible association with biotic and abiotic factors in that environment. Conventional biochemical tests identified Klebsiella sp, Morganella sp, Serratia sp, Escherichia sp, Enterobacter sp, Edwarsiella sp, Proteus sp, Citrobacter sp, Providencia sp, and Kluyvera sp. There was no correlation between antimicrobial resistance patterns of isolates and bacterial genera, but resistance patterns varied among water samples and between seasons. Resistance to multiple antimicrobials was common (61%). The percentage of bacteria resistant to at least one antimicrobial differed between the rainy (100%) and dry seasons (89%). Resistance to â-lactams and chloramphenicol was the most frequent and resistance to amikacin, gentamicin and kanamycin was less frequent. The main water variables examined (abiotic factors pH and temperature; biotic factor chlorophyll a concentration) did not influence antimicrobial resistance. Significant impact on freshwater enterobacteria, as evidenced by antimicrobial-multiple resistance and by the presence of blaTEM gene, may point to the fact that it has an important role in horizontal spread of resistance.

A comparative analysis of highly conserved sex-determining genes between Apis mellifera and Drosophila melanogaster

A comparison of the most conserved sex-determining genes between the fruit fly, Drosophila melanogaster, and the honey bee, Apis mellifera, was performed with bioinformatics tools developed for computational molecular biology. An initial set of protein sequences already described in the fruit fly as participants of the sex-determining cascade was retrieved from the Gene Ontology database (http://www.geneontology.org/) and aligned against a database of protein sequences predicted from the honey bee genome. The doublesex (dsx) gene is considered one of the most conserved sex-determining genes among metazoans, and a male-specific partial cDNA of putative A. mellifera dsx gene (Amdsx) was identified experimentally. The theoretical predictions were developed in the context of sequence similarity. Experimental evidence indicates that dsx is present in embryos and larvae, and that it encodes a transcription factor widely conserved in metazoans, containing a DM DNA-binding domain implicated in the regulation of the expression of genes involved in sexual phenotype formation.

Operon mer: bacterial resistance to mercury and potential for bioremediation of contaminated environments

Mercury is present in the environment as a result of natural processes and from anthropogenic sources. The amount of mercury mobilized and released into the biosphere has increased since the beginning of the industrial age. Generally, mercury accumulates upwards through aquatic food chains, so that organisms at higher trophic levels have higher mercury concentrations. Some bacteria are able to resist heavy metal contamination through chemical transformation by reduction, oxidation, methylation and demethylation. One of the best understood biological systems for detoxifying organometallic or inorganic compounds involves the mer operon. The mer determinants, RTPCDAB, in these bacteria are often located in plasmids or transposons and can also be found in chromosomes. There are two classes of mercury resistance: narrow-spectrum specifies resistance to inorganic mercury, while broad-spectrum includes resistance to organomercurials, encoded by the gene merB. The regulatory gene merR is transcribed from a promoter that is divergently oriented from the promoter for the other mer genes. MerR regulates the expression of the structural genes of the operon in both a positive and a negative fashion. Resistance is due to Hg2+ being taken up into the cell and delivered to the NADPH-dependent flavoenzyme mercuric reductase, which catalyzes the two-electron reduction of Hg2+ to volatile, low-toxicity Hg0. The potential for bioremediation applications of the microbial mer operon has been long recognized; consequently, Escherichia coli and other wild and genetically engineered organisms for the bioremediation of Hg2+-contaminated environments have been assayed by several laboratories

Molecular characterization of ABC transporter-encoding genes in Aspergillus nidulans

As a preliminary step towards characterizing genes encoding ATP-binding cassette (ABC) transporters that confer pleiotropic drug resistance in Aspergillus, we used a PCR-based approach to isolate four DNA fragments corresponding to different ABC type transporter genes. DNA sequencing and Southern blot analysis confirmed that they were distinct genes, which were designated abcA-D. One of these genes, abcD, was cloned and characterized. It was found to have a predicted 1,452-amino acid translation product with a calculated molecular mass of 147,467 kDa. The abcD gene specifies a single transcript of approximately 5.0 kb; there was a two- to six-fold enhancement of mRNA levels following exposure to miconazole, camptothecin, methotrexate, and ethidium bromide