Characterization of a New Glucose-Tolerant GH1 ß-Glycosidase from Aspergillus fumigatus with Transglycosylation Activity.

Concern over environmental impacts has spurred many efforts to replace fossil fuels with biofuels such as ethanol. However, for this to be possible, it is necessary to invest in other production technologies, such as second generation (2G) ethanol, in order to raise the levels of this product and meet the growing demand. Currently, this type of production is not yet economically feasible, due to the high costs of the enzyme cocktails used in saccharification stage of lignocellulosic biomass. In order to optimize these cocktails, the search for enzymes with superior activities has been the goal of several research groups. For this end, we have characterized the new ß-glycosidase AfBgl1.3 from A. fumigatus after expression and purification in Pichia pastoris X-33. Structural analysis by circular dichroism revealed that increasing temperature destructured the enzyme; the apparent Tm value was 48.5 °C. The percentages of α-helix (36.3%) and ß-sheet (12.4%) secondary structures at 25 °C were predicted. Biochemical characterization suggested that the optimal conditions for AfBgl1.3 were pH 6.0 and temperature of 40 °C. At 30 and 40 °C, the enzyme was stable and retained about 90% and 50% of its activity, respectively, after pre-incubation for 24 h. In addition, the enzyme was highly stable at pH between 5 and 8, retaining over 65% of its activity after pre-incubation for 48 h. AfBgl1.3 co-stimulation with 50-250 mM glucose enhanced its specific activity by 1.4-fold and revealed its high tolerance to glucose (IC50 = 2042 mM). The enzyme was active toward the substrates salicin (495.0 ± 49.0 U mg-1), pNPG (340.5 ± 18.6 U mg-1), cellobiose (89.3 ± 5.1 U mg-1), and lactose (45.1 ± 0.5 U mg-1), so it had broad specificity. The Vmax values were 656.0 ± 17.5, 706.5 ± 23.8, and 132.6 ± 7.1 U mg-1 toward p-nitrophenyl-ß-D-glucopyranoside (pNPG), D-(-)-salicin, and cellobiose, respectively. AfBgl1.3 displayed transglycosylation activity, forming cellotriose from cellobiose. The addition of AfBgl1.3 as a supplement at 0.9 FPU/g of cocktail Celluclast® 1.5L increased carboxymethyl cellulose (CMC) conversion to reducing sugars (g L-1) by about 26% after 12 h. Moreover, AfBgl1.3 acted synergistically with other Aspergillus fumigatus cellulases already characterized by our research group-CMC and sugarcane delignified bagasse were degraded, releasing more reducing sugars compared to the control. These results are important in the search for new cellulases and in the optimization of enzyme cocktails for saccharification.

Styrax camporum, a typical species of the Brazilian cerrado, attenuates DNA damage, preneoplastic lesions and oxidative stress in experimental rat colon carcinogenesis.

Styrax camporum Pohl, a typical species from the Brazilian cerrado, commonly known as "benjoeiro", is used to treat gastroduodenal diseases. In previous studies carried out by our research group, hydroalcoholic extract of S. camporum stems (SCHE) exhibited antigenotoxic and antiproliferative effects. For a comparative analysis of the chemopreventive effect of SCHE, the aim of this study was to investigate the influence of SCHE against carcinogen 1,2-dimethylhydrazine (DMH)-induced DNA damage and pre-neoplastic lesions in Wistar rat colon. Animals were treated orally with SCHE at 250, 500 or 1000 mg/kg body weight in conjunction with a subcutaneous injection of DMH. DNA damage was assessed using the comet assay while tpre-neoplastic lesions by aberrant crypt foci (ACF) assay. The following hepatic oxidative stress markers were determined including activities of catalase (CAT) and glutathione S-transferase (GST) as well as levels of reduced glutathione (GSH) and malondialdehyde (MDA). Treatment with SCHE was not genotoxic or carcinogenic at the highest dose tested (1000 mg/kg b.w.). The extract effectively inhibited DNA damage and pre-neoplastic lesions induced by DMH administration at all concentrations tested. Measurement of CAT, and GST activities and levels of GSH showed that SCHE did not reduce oxidative processes. In contrast, treatment with SCHE (1000 mg/kg b.w.) decreased liver MDA levels. Taken together, these findings suggested the chemopreventive effect attributed to SCHE in colon carcinogenesis, may be related to its capacity to inhibit DNA damage as well as an antioxidant action associated with its chemical constituents egonol and homoegonol.

LPMO AfAA9_B and Cellobiohydrolase AfCel6A from A. fumigatus Boost Enzymatic Saccharification Activity of Cellulase Cocktail.

Cellulose is the most abundant polysaccharide in lignocellulosic biomass, where it is interlinked with lignin and hemicellulose. Bioethanol can be produced from biomass. Since breaking down biomass is difficult, cellulose-active enzymes secreted by filamentous fungi play an important role in degrading recalcitrant lignocellulosic biomass. We characterized a cellobiohydrolase (AfCel6A) and lytic polysaccharide monooxygenase LPMO (AfAA9_B) from Aspergillus fumigatus after they were expressed in Pichia pastoris and purified. The biochemical parameters suggested that the enzymes were stable; the optimal temperature was ~60 °C. Further characterization revealed high turnover numbers (kcat of 147.9 s-1 and 0.64 s-1, respectively). Surprisingly, when combined, AfCel6A and AfAA9_B did not act synergistically. AfCel6A and AfAA9_B association inhibited AfCel6A activity, an outcome that needs to be further investigated. However, AfCel6A or AfAA9_B addition boosted the enzymatic saccharification activity of a cellulase cocktail and the activity of cellulase Af-EGL7. Enzymatic cocktail supplementation with AfCel6A or AfAA9_B boosted the yield of fermentable sugars from complex substrates, especially sugarcane exploded bagasse, by up to 95%. The synergism between the cellulase cocktail and AfAA9_B was enzyme- and substrate-specific, which suggests a specific enzymatic cocktail for each biomass by up to 95%. The synergism between the cellulase cocktail and AfAA9_B was enzyme- and substrate-specific, which suggests a specific enzymatic cocktail for each biomass.

Transcriptome and secretome analysis of Aspergillus fumigatus in the presence of sugarcane bagasse.

BACKGROUND: Sugarcane bagasse has been proposed as a lignocellulosic residue for second-generation ethanol (2G) produced by breaking down biomass into fermentable sugars. The enzymatic cocktails for biomass degradation are mostly produced by fungi, but low cost and high efficiency can consolidate 2G technologies. A. fumigatus plays an important role in plant biomass degradation capabilities and recycling. To gain more insight into the divergence in gene expression during steam-exploded bagasse (SEB) breakdown, this study profiled the transcriptome of A. fumigatus by RNA sequencing to compare transcriptional profiles of A. fumigatus grown on media containing SEB or fructose as the sole carbon source. Secretome analysis was also performed using SDS-PAGE and LC-MS/MS. RESULTS: The maximum activities of cellulases (0.032 U mL-1), endo-1,4-ß--xylanase (10.82 U mL-1) and endo-1,3-ß glucanases (0.77 U mL-1) showed that functional CAZymes (carbohydrate-active enzymes) were secreted in the SEB culture conditions. Correlations between transcriptome and secretome data identified several CAZymes in A. fumigatus. Particular attention was given to CAZymes related to lignocellulose degradation and sugar transporters. Genes encoding glycoside hydrolase classes commonly expressed during the breakdown of cellulose, such as GH-5, 6, 7, 43, 45, and hemicellulose, such as GH-2, 10, 11, 30, 43, were found to be highly expressed in SEB conditions. Lytic polysaccharide monooxygenases (LPMO) classified as auxiliary activity families AA9 (GH61), CE (1, 4, 8, 15, 16), PL (1, 3, 4, 20) and GT (1, 2, 4, 8, 20, 35, 48) were also differentially expressed in this condition. Similarly, the most important enzymes related to biomass degradation, including endoxylanases, xyloglucanases, ß-xylosidases, LPMOs, α-arabinofuranosidases, cellobiohydrolases, endoglucanases and ß-glucosidases, were also identified in the secretome. CONCLUSIONS: This is the first report of a transcriptome and secretome experiment of Aspergillus fumigatus in the degradation of pretreated sugarcane bagasse. The results suggest that this strain employs important strategies for this complex degradation process. It was possible to identify a set of genes and proteins that might be applied in several biotechnology fields. This knowledge can be exploited for the improvement of 2G ethanol production by the rational design of enzymatic cocktails.

Functional characterization of GH7 endo-1,4-ß-glucanase from Aspergillus fumigatus and its potential industrial application.

A gene encoding an endo-1,4-ß-glucanase (Afu6g01800) from A. fumigatus was cloned into the vector pET-28a(+) and expressed in the E. coli strain RosettaTM (DE3) pLysS. Sequence analysis indicated that the enzyme Af-EGL7 belonged to the GH7 family. The gene Af-egl7 encoded a protein comprising 460 amino acids, with a CBM1 domain at residues 424-460 and molecular mass of 52 kDa, as estimated by SDS-PAGE. This enzyme was optimally active at pH and temperatures ranging from 4.5 to 5.5 and from 40 to 60 °C, respectively. Mn2+ addition significantly enhanced the Af-EGL7 cellulase activity by 233%, whereas SDS addition fully inhibited this activity. Higher activity was observed toward ß-glucan than toward xyloglucan and CM-Cellulose, suggesting that the enzyme corresponds to a ß-1,3-1,4-glucanase. qRT-PCR in different culture media helped to establish the time-course expression profile. Different polysaccharides induced the gene Af-egl7 in a time-dependent manner; in the particular case of the substrate sugarcane exploded bagasse (SEB), Af-egl7 was induced 2500-fold. Upon addition to a commercial cellulase cocktail, Af-EGL7 significantly improved SEB saccharification, which suggested that the enzyme Af-EGL7 had great potential to hydrolyze complex biomass. From a biotechnological point of view, A. fumigatus Af-EGL7 is a promising candidate to enhance enzyme cocktails used in biorefineries such as consolidated bioprocessing.

Heterologous expression of mitochondrial nicotinamide adenine dinucleotide transporter (Ndt1) from Aspergillus fumigatus rescues impaired growth in Δndt1Δndt2 Saccharomyces cerevisiae strain.

Our understanding of nicotinamide adenine dinucleotide mitochondrial transporter 1 (Ndt1A) in Aspergillus fumigatus remains poor. Thus, we investigated whether Ndt1A could alter fungi survival. To this end, we engineered the expression of an Ndt1A-encoding region in a Δndt1Δndt2 yeast strain. The resulting cloned Ndt1A protein promoted the mitochondrial uptake of nicotinamide adenine dinucleotide (NAD+), generating a large mitochondrial membrane potential. The NAD+ carrier utilized the electrochemical proton gradient to drive NAD+ entrance into mitochondria when the mitochondrial membrane potential was sustained by succinate. Its uptake has no impact on oxidative stress, and Ndt1A expression improved growth and survival of the Δndt1Δndt2 Saccharomyces cerevisiae strain.

Novel Insights into the Molecular Mechanisms Involved in the Neuroprotective Effects of C-Phycocyanin against Brain Ischemia in Rats.

BACKGROUND: Ischemic stroke produces a large health impact worldwide, with scarce therapeutic options. OBJECTIVE: This study aimed to reveal the role of NADPH oxidase and neuroinflammatory genes in the cerebral anti-ischemic effects of C-Phycocyanin (C-PC), the chief biliprotein of Spirulina platensis. METHODS: Rats with either focal cerebral ischemia/reperfusion (I/R) or acute brain hypoperfusion, received C-PC at different doses, or a vehicle, for up to 6 h post-stroke. Neurological, behavioral and histochemical parameters were assessed in I/R rats at 24 h. Cerebral gene expression and hippocampal neuron viability were evaluated in hypoperfused rats at acute (24 h) or chronic phases (30 days), respectively. A molecular docking analysis of NOX2 and C-PC-derived Phycocyanobilin (PCB) was also performed. RESULTS: C-PC, obtained with a purity of 4.342, significantly reduced the infarct volume and neurological deficit in a dose-dependent manner, and improved the exploratory activity of I/R rats. This biliprotein inhibited NOX2 expression, a crucial NADPH oxidase isoform in the brain, and the superoxide increase produced by the ischemic event. Moreover, C-PC-derived PCB showed a high binding affinity in silico with NOX2. C-PC downregulated the expression of pro-inflammatory genes (IFN-γ, IL-6, IL-17A, CD74, CCL12) and upregulated immune suppressive genes (Foxp3, IL-4, TGF-ß) in hypoperfused brain areas. This compound also decreased chronic neuronal death in the hippocampus of hypoperfused rats. CONCLUSION: These results suggest that the inhibition of cerebral NADPH oxidase and the improvement of neuroinflammation are key mechanisms mediating the neuroprotective actions of C-PC against brain ischemia.

Classical and alternative components of the mitochondrial respiratory chain in pathogenic fungi as potential therapeutic targets.

The frequency of opportunistic fungal infection has increased drastically, mainly in patients who are immunocompromised due to organ transplant, leukemia or HIV infection. In spite of this, only a few classes of drugs with a limited array of targets, are available for antifungal therapy. Therefore, more specific and less toxic drugs with new molecular targets is desirable for the treatment of fungal infections. In this context, searching for differences between mitochondrial mammalian hosts and fungi in the classical and alternative components of the mitochondrial respiratory chain may provide new potential therapeutic targets for this purpose.

Characterization of Rubus fruticosus mitochondria and salicylic acid inhibition of reactive oxygen species generation at Complex III/Q cycle: potential implications for hypersensitive response in plants.

In addition to adenosine triphosphate (ATP) production, mitochondria have been implicated in the regulation of several physiological responses in plants, such as programmed cell death (PCD) activation. Salicylic acid (SA) and reactive oxygen species (ROS) are essential signaling molecules involved in such physiological responses; however, the mechanisms by which they act remain unknown. In non-photosynthesizing tissues, mitochondria appear to serve as the main source of ROS generation. Evidence suggests that SA and ROS could regulate plant PCD through a synergistic mechanism that involves mitochondria. Herein, we isolate and characterize the mitochondria from non-photosynthesizing cell suspension cultures of Rubus fruticosus. Furthermore, we assess the primary site of ROS generation and the effects of SA on isolated organelles. Mitochondrial Complex III was found to be the major source of ROS generation in this model. In addition, we discovered that SA inhibits the electron transport chain by inactivating the semiquinone radical during the Q cycle. Computational analyses confirmed the experimental data, and a mechanism for this action is proposed.

Age-Related and Gender-Related Increases in Colorectal Cancer Mortality Rates in Brazil Between 1979 and 2015: Projections for Continuing Rises in Disease.

PURPOSE: Brazil is the largest country in South America. Although a developing nation, birth rates have been decreasing in the last few decades, while its overall population is undergoing lifestyle changes and ageing significantly. Moreover, Brazil has had increasingly high mortality rates related to colorectal cancer (CRC). Herein, we investigated whether the Brazilian population is exhibiting increasing mortality rates related to colon cancer (CC) or rectal cancer (RC) in recent years. METHODS: We examined data from the Brazilian Federal Government from 1979 to 2015 to determine whether CRC mortality and the population ageing process may be associated. RESULTS: Our mathematical modelling suggests that mortality rates related to CC and RC events in the Brazilian population may increase by 79% and 66% in the next 24 years, respectively. This finding led us to explore the mortality rates for both diseases in the country, and we observed that the highest levels were in the south and southeast regions from the year 2000 onwards. CC events appear to decrease life expectancy among people during their second decade of life in recent years, whereas RC events induced decreases in life expectancy in those aged >30 years. Additionally, both CC and RC events seem to promote significant mortality rates in the male population aged > 60 years and living in the southern states. CONCLUSION: Our dataset suggests that both CC and RC events may lead to a significantly increasing number of deaths in the Brazilian male population in coming years.

Effects of liquid extract from Plinia cauliflora fruits residues on Chinese hamsters biochemical parameters.

Plinia cauliflora (Mart.) Kausel, popularly known as jabuticaba, is rich in polyphenols. Phenolic compounds exhibit several biological properties, which reflect on biomarkers such as biochemical parameters. In the present study, we evaluated the plasmatic levels of glucose, total cholesterol, HDL-cholesterol, triglycerides, and uric acid of Chinese hamsters fed for 45 days with a regular diet or cholesterol-enriched diet supplemented with a liquid extract obtained from P. cauliflora fruits residues standardized in ellagic acid and total phenolic compounds. The results showed that the concentrated extract obtained from jabuticaba residues increased the glycemia of animals fed with a regular diet and reduced the plasmatic uric acid levels of animals fed with a cholesterol-enriched diet. Since hyperuricemia is considered to be a significant risk factor of metabolic disorders and the principal pathological basis of gout, the liquid extract from P. cauliflora fruits residues would be a promising candidate as a novel hypouricaemic agent for further investigation.

The roles played by Aspergillus nidulans apoptosis-inducing factor (AIF)-like mitochondrial oxidoreductase (AifA) and NADH-ubiquinone oxidoreductases (NdeA-B and NdiA) in farnesol resistance.

Farnesol (FOH) is a nonsterol isoprenoid produced by dephosphorylation of farnesyl pyrophosphate, a catabolite of the cholesterol biosynthetic pathway. These isoprenoids inhibit proliferation and induce apoptosis. Here, we show that Aspergillus nidulans AifA encoding the apoptosis-inducing factor (AIF)-like mitochondrial oxidoreductase plays a role in the function of the mitochondrial Complex I. Additionally, we demonstrated that ndeA-B and ndiA encode external and internal alternative NADH dehydrogenases, respectively, that have a function in FOH resistance. When exposed to FOH, the ΔaifA and ΔndeA strains have increased ROS production while ΔndeB, ΔndeA ΔndeB, and ΔndiA mutant strains showed the same ROS accumulation than in the absence of FOH. We observed several compensatory mechanisms affecting the differential survival of these mutants to FOH.

Chemical features of the photosensitizers new methylene blue N and S137 influence their subcellular localization and photoinactivation efficiency in Candida albicans.

Antimicrobial photodynamic treatment (APDT) has emerged as an effective therapy against pathogenic fungi with both acquired and intrinsic resistance to commonly used antifungal agents. Success of APDT depends on the availability of effective photosensitizers capable of acting on different fungal structures and species. Among the phenothiazinium dyes tested as photoantifungals, new methylene blue N (NMBN) and the novel pentacyclic compound S137 are the most efficient. In the present study we compared the effects of APDT with NMBN and S137 on the survival of Candida albicans and employed a set of fluorescent probes (propidium iodide, FUN-1, JC-1, DHR-123 and DHE) together with confocal microscopy and flow cytometry to evaluate the effects of these two chemically diverse photosensitizers on cell membrane permeability, metabolism and redox status, and mitochondrial activity. Taken together, our results indicate that, due to chemical features resulting in different lipophilicity, NMBN and S137 localize to distinct subcellular structures and hence inactivate C. albicans cells via different mechanisms. S137 localizes mostly to the cell membrane and, upon light exposure, photo-oxidizes membrane lipids. NMBN readily localizes to mitochondria and exerts its photodynamic effects there, which was observed to be a less effective way to achieve cell death at lower light fluences.

Phenotypic analysis of genes whose mRNA accumulation is dependent on calcineurin in Aspergillus fumigatus.

Calcineurin plays an important role in the control of cell morphology and virulence in fungi. Calcineurin is a serine/threonine-specific protein phosphatase heterodimer consisting of a catalytic subunit A and a regulatory subunit B. A mutant of Aspergillus fumigatus lacking the calcineurin A (calA) catalytic subunit exhibited defective hyphal morphology related to apical extension and branching growth, which resulted in drastically decreased filamentation. Here, we investigated which pathways are influenced by A. fumigatus calcineurin during proliferation by comparatively determining the transcriptional profile of A. fumigatus wild type and DeltacalA mutant strains. Our results showed that the mitochondrial copy number is reduced in the DeltacalA mutant strain, and the mutant has increased alternative oxidase (aoxA) mRNA accumulation and activity. Furthermore, we identified four genes that encode transcription factors that have increased mRNA expression in the DeltacalA mutant. Deletion mutants for these transcription factors had reduced susceptibility to itraconazole, caspofungin, and sodium dodecyl sulfate (SDS).

Cubebin and derivatives as inhibitors of mitochondrial complex I. Proposed interaction with subunit B8.

The effects on mitochondrial respiration and complex I NADH oxidase activity of cubebin and derivatives were evaluated. The compounds inhibited the state 3 glutamate/malate-supported respiration of hamster liver mitochondria with IC(50) values ranging from 12.16 to 83.96 microM. NADH oxidase reaction was evaluated in submitochondrial particles. The compounds also inhibited this activity, showing the same order of potency observed for effects on state 3 respiration, as well as a tendency towards a non-competitive type of inhibition (K(I) values ranging from 0.62 to 16.1 microM). A potential binding mode of these compounds with complex I subunit B8, assessed by docking calculations, is proposed.

Lytic Polysaccharide Monooxygenase from Aspergillus fumigatus can Improve Enzymatic Cocktail Activity During Sugarcane Bagasse Hydrolysis.

BACKGROUND: Lytic Polysaccharide Monooxygenases (LPMOs) are auxiliary accessory enzymes that act synergistically with cellulases and which are increasingly being used in secondgeneration bioethanol production from biomasses. Several LPMOs have been identified in various filamentous fungi, including Aspergillus fumigatus. However, many LPMOs have not been characterized yet. OBJECTIVE: To report the role of uncharacterized A. fumigatus AfAA9_B LPMO. METHODS: qRT-PCR analysis was employed to analyze the LPMO gene expression profile in different carbon sources. The gene encoding an AfAA9_B (Afu4g07850) was cloned into the vector pET- 28a(+), expressed in the E. coli strain RosettaTM (DE3) pLysS, and purified by a Ni2+-nitrilotriacetic (Ni-NTA) agarose resin. To evaluate the specific LPMO activity, the purified protein peroxidase activity was assessed. The auxiliary LPMO activity was investigated by the synergistic activity in Celluclast 1.5L enzymatic cocktail. RESULTS: LPMO was highly induced in complex biomass like sugarcane bagasse (SEB), Avicel® PH-101, and CM-cellulose. The LPMO gene encoded a protein comprising 250 amino acids, without a CBM domain. After protein purification, the AfAA9_B molecular mass estimated by SDSPAGE was 35 kDa. The purified protein specific peroxidase activity was 8.33 ± 1.9 U g-1. Upon addition to Celluclast 1.5L, Avicel® PH-101 and SEB hydrolysis increased by 18% and 22%, respectively. CONCLUSION: A. fumigatus LPMO is a promising candidate to enhance the currently available enzymatic cocktail and can therefore be used in second-generation ethanol production.

SET protein accumulation prevents cell death in head and neck squamous cell carcinoma through regulation of redox state and autophagy.

Molecular alterations in cell death pathways and imbalances in regulators of up- or downstream signaling pathways can lead to resistance to cell death, which is one of the hallmarks of cancer. These signaling modifications are strategies that tumor cells use to resist chemotherapy and that contribute to the high recurrence rate of head and neck squamous cell carcinoma (HNSCC). The SET oncoprotein is a PP2A inhibitor that accumulates in HNSCC and represents a promising therapeutic target. Here we report the role that SET protein plays in resistance to death of two HNSCC cell lines: Cal 27 and HN13. SET protein regulated intracellular redox balance by controlling cellular localization of APE 1 - an endonuclease that is part of the SET complex and regulates antioxidant gene transcription. SET protein knockdown (siSET) associated with tert-butyl hydroperoxide-induced oxidative stress sensitized Cal 27 and HN13 cells to apoptosis via the extrinsic and intrinsic pathways, respectively. SET protein upregulated autophagy in HNSCC cells in a PP2A-dependent manner and apparently regulated ULK1 expression. The fact that siSET lowered Bcl-2 phosphorylation levels indicated that SET protein interfered with an alternative pathway that modulated autophagy in HNSCC cells. Overall, SET protein regulated intracellular redox state and sustained autophagy in HNSCC cells, which may explain resistance to death of HNSCC cells. Altogether, the findings reported herein support SET protein as therapeutic target for HNSCC.

Silencing of mitochondrial alternative oxidase gene of Aspergillus fumigatus enhances reactive oxygen species production and killing of the fungus by macrophages.

We previously demonstrated that conidia from Aspergillus fumigatus incubated with menadione and paraquat increases activity and expression of cyanide-insensitive alternative oxidase (AOX). Here, we employed the RNA silencing technique in A. fumigatus using the vector pALB1/aoxAf in order to down-regulate the aox gene. Positive transformants for aox gene silencing of A. fumigatus were more susceptible both to an imposed in vitro oxidative stress condition and to macrophages killing, suggesting that AOX is required for the A. fumigatus pathogenicity, mainly for the survival of the fungus conidia during host infection and resistance to reactive oxygen species generated by macrophages.

Increased exposure to pesticides and colon cancer: Early evidence in Brazil.

Environmental factors may increase colon cancer (CC) risk. It has been suggested that pesticides could play a significant role in the etiology of this malignancy. As agriculture is one of the mainstays of the Brazilian economy, this country has become the largest pesticides consumer worldwide. The CC burden is also increasing in Brazil. Herein, we examined data from the Brazilian Federal Government to determine whether CC mortality and pesticide consumption may be associated. Database of the Ministry of Health provided CC mortality data in Brazil, while pesticide usage was accessed at the website of Brazilian Institute of Environment and Renewable Natural Resources. The CC mortality in the Brazilian states was calculated as standard mortality rates (SMR). All Bayesian analysis was performed using a Markov chain Monte Carlo method in WinBUGS software. We observed that CC mortality has exhibited a steady increase for more than a decade, which correlated with the amount of sold pesticides in the country. Both observations are concentrated in the Southern and the Southeast regions of Brazil. Although ecological studies like ours have methodological limitations, the current dataset suggests the possibility that pesticide exposure may be a risk factor for CC. It warrants further investigation.

Effects of liquid extract from Plinia cauliflora fruits residues on Chinese hamsters biochemical parameters / Efeitos do extrato líquido de resíduos de frutos de Plinia cauliflora sobre os parâmetros bioquímicos de hamsters chineses

Plinia cauliflora (Mart.) Kausel, popularly known as jabuticaba, is rich in polyphenols. Phenolic compounds exhibit several biological properties, which reflect on biomarkers such as biochemical parameters. In the present study, we evaluated the plasmatic levels of glucose, total cholesterol, HDL-cholesterol, triglycerides, and uric acid of Chinese hamsters fed for 45 days with a regular diet or cholesterol-enriched diet supplemented with a liquid extract obtained from P. cauliflora fruits residues standardized in ellagic acid and total phenolic compounds. The results showed that the concentrated extract obtained from jabuticaba residues increased the glycemia of animals fed with a regular diet and reduced the plasmatic uric acid levels of animals fed with a cholesterol-enriched diet. Since hyperuricemia is considered to be a significant risk factor of metabolic disorders and the principal pathological basis of gout, the liquid extract from P. cauliflora fruits residues would be a promising candidate as a novel hypouricaemic agent for further investigation.

Plinia cauliflora (Mart.) Kausel, popularmente conhecida como jabuticaba, é rica em polifenois. Os compostos fenólicos apresentam diversas propriedades biológicas, que refletem em biomarcadores, como os parâmetros bioquímicos. No presente estudo, avaliamos os níveis plasmáticos de glicose, colesterol total, HDL-colesterol, triglicerídeos e ácido úrico em hamsters chineses alimentados por 45 dias com dieta regular ou dieta enriquecida com colesterol suplementada com extrato líquido obtido de resíduos de frutos de P. cauliflora padronizado em ácido elágico e compostos fenólicos totais. Os resultados mostraram que o extrato concentrado obtido dos resíduos de jabuticaba aumentou a glicemia dos animais alimentados com dieta regular e reduziu os níveis plasmáticos de ácido úrico dos animais alimentados com dieta rica em colesterol. Uma vez que a hiperuricemia é considerada um fator de risco significativo de distúrbios metabólicos e a principal base patológica da gota, o extrato líquido dos resíduos de frutas de P. cauliflora seria um candidato promissor como um novo agente hipouricêmico para investigação posterior.