Structure of Rhizobium sp. 4-9 histamine dehydrogenase and analysis of the electron transfer pathway to an abiological electron acceptor.

Histamine dehydrogenase from the gram-negative bacterium Rhizobium sp. 4-9 (HaDHR) is a member of a small family of dehydrogenases containing a covalently attached FMN, and the only member so far identified to date that does not exhibit substrate inhibition. In this study, we present the 2.1 Å resolution crystal structure of HaDHR. This new structure allowed for the identification of the internal electron transfer pathway to abiological ferrocene-based mediators. Alanine 437 was identified as the exit point of electrons from the Fe4S4 cluster. The enzyme was modified with a Ser436Cys mutation to facilitate covalent attachment of a ferrocene moiety. When modified with Fc-maleimide, this new construct demonstrated direct electron transfer from the enzyme to a gold electrode in a histamine concentration-dependent manner without the need for any additional electron mediators.

Polycystic ovary syndrome: clinical and laboratory variables related to new phenotypes using machine-learning models.

PURPOSE: Polycystic Ovary Syndrome (PCOS) is the most frequent endocrinopathy in women of reproductive age. Machine learning (ML) is the area of artificial intelligence with a focus on predictive computing algorithms. We aimed to define the most relevant clinical and laboratory variables related to PCOS diagnosis, and to stratify patients into different phenotypic groups (clusters) using ML algorithms. METHODS: Variables from a database comparing 72 patients with PCOS and 73 healthy women were included. The BorutaShap method, followed by the Random Forest algorithm, was applied to prediction and clustering of PCOS. RESULTS: Among the 58 variables investigated, the algorithm selected in decreasing order of importance: lipid accumulation product (LAP); abdominal circumference; thrombin activatable fibrinolysis inhibitor (TAFI) levels; body mass index (BMI); C-reactive protein (CRP), high-density lipoprotein cholesterol (HDL-c), follicle-stimulating hormone (FSH) and insulin levels; HOMA-IR value; age; prolactin, 17-OH progesterone and triglycerides levels; and family history of diabetes mellitus in first-degree relative as the variables associated to PCOS diagnosis. The combined use of these variables by the algorithm showed an accuracy of 86% and area under the ROC curve of 97%. Next, PCOS patients were gathered into two clusters in the first, the patients had higher BMI, abdominal circumference, LAP and HOMA-IR index, as well as CRP and insulin levels compared to the other cluster. CONCLUSION: The developed algorithm could be applied to select more important clinical and biochemical variables related to PCOS and to classify into phenotypically different clusters. These results could guide more personalized and effective approaches to the treatment of PCOS.

Low validity of predictive equations for calculating resting energy expenditure in overweight and obese women with polycystic ovary syndrome.

BACKGROUND: Predictive equations are the main clinical tools for determining resting energy expenditure (REE). However, their adequate use in overweight and obese individuals is unclear. Thus, we investigated the best predictive equations for estimating REE in overweight and obese women with polycystic ovary syndrome (PCOS). METHODS: Eleven analyses were performed with prediction equations (pREE) based on anthropometric parameters in 30 overweight or obese women with PCOS without other chronic diseases. The measured REE (mREE) was calculated by indirect calorimetry. The validity of the equations was investigated by comparison, accuracy and agreement tests between pREE and mREE at both the individual and group level. RESULTS: Four analyses were similar to those of mREE, and smallest mean differences were observed for the World Health Organization/Food and Agriculture Organization of the United Nations/United Nations University (WHO/FAO/UNU) considering weight (W) [0.07 (1.13) MJ (16 [270] kcal)]. Individual accuracy was greater than 50% for Harris and Benedict, Müller and Lazzer equations. The percentage of REE underestimation ranged between 16.7% and 73.3%, whereas higher rates of overestimation were observed in the De Luis (66.7%) and Ireton-Jones (43.3%) equations. Mean bias at the group level was lowest in the WHO/FAO/UNU W and WHO/FAO/UNU considering weight and height (WH), Müller and Lazzer equations (-2.8 to 0.5). The WHO/FAO/UNU W and WHO/FAO/UNU WH formulas were optimal in individual agreement (33.3%). CONCLUSIONS: FAO/WHO/UNU W equations may estimate the REE in overweight and obese women with PCOS. However, the low individual accuracy and agreement in relation to mREE suggest caution regarding when to use the formula to perform an individual nutritional plan.

Non-alcoholic fatty liver disease in women with polycystic ovary syndrome: systematic review and meta-analysis.

PURPOSE: Non-alcoholic fatty liver disease (NAFLD) is an insidious pathologic condition that can manifest from simple steatosis to steatohepatitis (NASH) with potential progression to cirrhosis. Like the polycystic ovary syndrome (PCOS), NAFLD is associated with obesity, diabetes mellitus, insulin resistance and metabolic syndrome. PCOS women have an increased risk of NAFLD, but it is debatable which features of PCOS, either specific (androgen excess) or unspecific (metabolic derangements) affect the NAFLD risk. METHODS: We performed a systematic review and meta-analysis of studies that addressed the association of PCOS and NAFLD. We selected 17 studies published between 2007 and 2017 that included 2734 PCOS patients and 2561 controls of similar age and body mass index (BMI). RESULTS: PCOS patients have increased prevalence of NAFLD (odds ratio 2.54, 95% confidence interval 2.19-2.95). PCOS women with hyperandrogenism (classic phenotype) have a higher prevalence of NAFLD compared to women with PCOS without hyperandrogenism, even after correction for confounding variables. Among women with PCOS, those with NAFLD have higher serum total testosterone (mean difference 0.40 nmol/L, 95% CI 0.29-0.50 nmol/L) and free androgen index (mean difference 4.46, 95% CI 3.53-5.39) than those without NAFLD. The studies that used multivariate analysis controlling for age, BMI, triglycerides, and insulin resistance index confirmed that serum androgens are independent predictors of NAFLD in women with PCOS. CONCLUSION: The prevalence of NAFLD is increased in women with PCOS and the presence of NAFLD is associated with high serum androgen levels, in addition to obesity and insulin resistance.

Poor quality diet is associated with overweight status and obesity in patients with polycystic ovary syndrome.

BACKGROUND: The high rates of overweight status observed in women with polycystic ovary syndrome (PCOS) may reflect dietary intake, and so it is important to investigate diet quality and its relationship with the rates of overweight status and obesity among these patients. METHODS: A cross-sectional study was conducted in which 100 women with PCOS (Rotterdam criteria) were evaluated considering anthropometric and dietary data. The anthropometric evaluation included the measurement of weight, height, body mass index (BMI), waist circumference (WC), hip circumference and waist-hip ratio. Food intake data were collected from two 24-h dietary recalls to assess dietary patterns using the Brazilian Healthy Eating Index - Revised (BHEI-R). RESULTS: The anthropometric analysis indicated a high prevalence of overweight status, obesity and increased visceral fat (30.0%, 60.0% and 90.0%, respectively). The mean BHEI-R score was 56.1 ± 12.0 points (range 34.5-77.5 points). Diet quality was negatively correlated with obesity, which was evaluated by BMI (r = -0.248; P = 0.013) and WC (r = -0.278; P = 0.005). CONCLUSIONS: Dietary interventions focused on improvement of diet quality should be targeted to treat patients with PCOS because obesity in these women is associated with worsening endocrine, metabolic and reproductive functions.

Molecular typing of Salmonella from Sergipe, Northeastern Brazil, showing the epidemiological relationship between poultry and human infection.

Randomly amplified polymorphic DNA (RAPD) has been widely used for epidemiological and phylogenetic purposes ow-ing to its rapidity and efficiency. The aim of this study was to perform genome typing of Salmonella samples isolated from different sources by RAPD profiling. Thirty-three Salmonella samples from the bacterial collection of the Laboratório de Virologia Comparada, Departamento de Morfologia, Universidade Federal de Sergipe, Brazil, and two standard samples were used. RAPD profiling was conducted using six primers of the Ready-To-Go RAPD system. The amplified products were electro-phoresed on 5% polyacrylamide gel and silver-stained. RAPD analysis resulted in reproducible and stable banding patterns and showed high genetic diversity among the isolated strains. The Primer P1-generated dendrogram showed an epidemiologic relationship between the human and poultry isolated samples, highlighting the usefulness of RAPD for molecular typing and epidemiological studies.

HBV whole-genome mutation profile in HIV-1/HBV coinfected patients in a long-term follow-up study.

PURPOSE: Human immunodeficiency virus (HIV-1)-infected patients frequently harbour hepatitis B and C viruses (HBV and HCV, respectively). Possible modifications of the natural history of hepatitis B may occur. The aim of this study was to characterise HBV diversity and evolutionary and mutational viral genome profiles in HIV-1/HBV coinfections. METHODS: HIV-1 and HBV markers determinations (Roche, FRG; Abbott, USA) and HBV genome-length retrospective analysis were performed in follow-up isolates from patients who were either stably HBsAg-negative with a low level of HBV DNA (occult hepatitis B infection, OBI) or HBsAg-positive with a high level of HBV DNA. Phylogenetic analysis (maximum likelihood method, MEGA5), statistical analysis and evolutionary rates calculation (d S/d N) were applied. RESULTS: Positive selection pressures in the PreS/S region and a significantly higher number of mutations in this region including the major hydrophilic region (MHR) and the "a" determinant were shown in HBsAg-negative (possibly OBI) compared to stably HBsAg-positive HIV-1/HBV subgenotypes D3/A2 coinfected patients. Mutants previously described in HIV-1/HBV coinfected patients were found. Known mutants Y100C, P127T and P120A associated to Y134H and S143T and new S mutants, which may potentially affect HBsAg expression and secretion and anti-HBs binding, were detected in baseline sera persisting up to the end of 9 years follow-up. Known mutations of BCP, Pre-C, C and X regions were also characterised. Natural mutants strictly known as being involved in diagnostic failure were not detected; however, numerous corresponding sites showed amino acid variations. CONCLUSIONS: Evolutionary and genotypic differences observed, particularly in the PreS/S region, between HBsAg-negative (OBI) and HBsAg-positive HIV-1/HBV coinfected patients, may contribute, in association with mutations of other genomic regions, to the HBsAg-negative phenotype.

Hepatitis E virus and hepatitis A virus exposures in an apparently healthy high-risk population in Italy.

PURPOSE: The prevalence of anti-hepatitis E virus (HEV) and anti-hepatitis A virus (HAV), as well as the possible links with socio-demographic and other viral risks factors, were evaluated in an inmates population. METHODS: The study population consisted of 973 consecutively recruited inmates of eight Italian prisons. RESULTS: The anti-HEV prevalence was 11.6 % (113/973). It increased significantly by age (χ(2) for linear trend: p = 0.001) and was significantly higher among non-Italian compared to Italian inmates (15.3 vs. 10.7 %, respectively). Age >40 years [odds ratio (OR) 2.1; 95 % confidence interval (CI) 1.4-3.1], non-Italian citizenship (OR 1.8; 95 % CI 1.1-2.9) and anti-HIV seropositivity (OR 2.2; 95 % CI 1.2-4.2) were the only factors independently associated to anti-HEV positivity by logistic regression analysis. The overall anti-HAV prevalence was 86.4 %, and was significantly higher in non-Italian compared to Italian prisoners (92.6 vs. 84.9 %, respectively; p = 0.02). Age older than 40 years (OR 3.6; 95 % CI 2.2-5.9), <5 years formal education (OR 2.1; 95 % CI 1.3-3.2) and non-Italian nationality (OR 2.7; 95 % CI 1.5-4.8) were factors independently associated to anti-HAV positivity by the logistic regression analysis. CONCLUSIONS: Compared to the general population, significantly higher anti-HEV and anti-HAV prevalences were observed in an inmates population in Italy. Old age and non-Italian nationality were factors independently related to both HEV and HAV exposures. This data suggest the important role of low socio-economic factors in the transmission of both infections in high-risk populations. The possible epidemiological and/or pathogenetic links between HEV and HIV exposures need to be studied further.

Correlation between plasminogen activator inhibitor-1 (PAI-1) promoter 4G/5G polymorphism and metabolic/proinflammatory factors in polycystic ovary syndrome.

Polycystic Ovary Syndrome (PCOS) is the most common cause of subfertility associated to metabolic disorders. The aim of this study was to correlate metabolic and proinflammatory factors in women with PCOS. The frequency of Plasminogen Activator Inhibitor-1 (PAI-1) promoter 4 G/5 G polymorphism was also compared to healthy controls. We evaluated 79 PCOS and 79 healthy women. PAI-1 levels are positively correlated with proinflammatory factors in PCOS group. 4 G allele in PAI-1 gene was more frequent in PCOS and the 4G/4 G genotype was associated with increased PAI-1 levels. A correlation between insulin resistance and proinflammatory and overweight was also observed. C-reactive protein, serum levels of vascular cell adhesion molecule-1 (sVCAM-1), Lipid Accumulation Product (LAP) and vitamin D are good tools to evaluated factors associated to cardiovascular risk in women with PCOS.

Genetic composition of a Brazilian population: the footprint of the Gold Cycle.

Ancestry-informative markers (AIMs) are powerful tools for inferring the genetic composition of admixed populations. In this study, we determined the genetic ancestry of the Ouro Preto (Brazil) population and evaluated the association between ancestry and self-reported skin color. The genetic ancestry of 189 children and adolescents was estimated by genotyping 15 AIMs. The estimate of population admixture was determined using the Bayesian Markov Chain Monte Carlo (MCMC) method implemented in two different programs (STRUCTURE and ADMIXMAP). Volunteers self-reported their skin colors. The European ancestry contribution ranged from 0.503 to 0.539, the African contribution ranged from 0.333 to 0.425, and the Amerindian component ranged from 0.04 to 0.164. The relative contributions of African (P < 0.016) and European (P < 0.011) ancestry differed significantly among skin color groups, except between black and dark-brown groups. The population of Ouro Preto has a higher contribution of African ancestry compared to the mean for the southeast region of Brazil. Therefore, extrapolating the African ancestry contribution for southeastern Brazil to the Ouro Preto population would underestimate the actual value for this city. We also showed that self-reported skin color could be appropriate for describing the genetic structure of this particular population.

Differences between risk perception and risk-taking are related to impulsivity levels.

Background: Although there is broad agreement that perceived risks determine risk-taking behavior, previous research has shown that this association may not be as straightforward as expected. The main objective of this study was to investigate if the levels of impulsivity can explain part of these controversial findings. Method: A total of 1579 participants (Mage = 23.06, from 18 to 60 years; 69.4% women) were assessed for levels of risk perception, risk-taking avoidance, and impulsivity. Results: The results showed that while impulsivity was significantly and negatively related to both risk perception and risk-taking avoidance, the relationship with risk-taking avoidance was significantly stronger than with risk perception. The levels of impulsivity predicted risk-taking avoidance even when controlling for risk perception. Conclusions: These findings indicate that impulsivity can differentially affect risk perception and risk-taking. We propose that the stronger influence of impulsivity on risk-taking is due to the greater reliance of risk-taking, compared with risk perception, on automatic processes guided by impulses and emotions.

Chemical composition, in vitro larvicidal and antileishmanial activities of the essential oil from Citrus reticulata Blanco fruit peel.

Numerous studies have investigated the chemical composition and biological activities of essential oils from different Citrus species fruit peel, leaves and flowers. This paper aims to investigate the chemical composition, larvicidal and antileishmanial activities of essential oil from Citrus reticulata fruit peel (CR-EO). CR-EO was obtained by hydrodistillation in a Clevenger-type apparatus and its chemical composition was analyzed by GC-MS and GC-FID. Limonene (85.7%), É£-terpinene (6.7%) and myrcene (2.1%) were identified as its major components. CR-EO showed high activity against promastigote forms of Leishmania amazonensis (IC50 = 8.23 µg/mL). CR-EO also exhibited high larvicidal activity against third instar Aedes aegypti larvae at a lethal concentration (LC50 = 58.35 µg/mL) and 100% mortality at 150 µg/mL. This study suggests, for the first time, the potential use of CR-EO against this important mosquito-borne viral disease caused by the genus Aedes.

Chemical composition and phytotoxicity of essential oils of Croton doctoris S. Moore (Euphorbiaceae).

Essential oils from the stems and leaves of Croton doctoris were analyzed by gas chromatography and mass spectrometry, resulting in 22 identified compounds. The effects of these essential oils on the germination, root and shoot growth, total chlorophyll content, potential root respiration, peroxidase activity, catalase, superoxide dismutase, and mitotic index in lettuce and onion were determined. Antioxidant, antimicrobial, and cytotoxic activity were also investigated. The results revealed that the stem oil consisted of 15 compounds, of which caryophyllene oxide (24.5%) and E-caryophyllene (13.3%) were the major constituents. The leaf oil contained E-caryophyllene (39.6%) and α-humulene (13.2%) as major compounds. The oils inhibited the germination and growth of lettuce and onion seedlings and reduced chlorophyll content, root respiration, and cell division. They also caused oxidative stress, indicated by the increased activity of the evaluated antioxidant enzymes. These abnormal physiological processes contributed to the inhibition of plant growth. The most pronounced phytotoxic effects were observed in the stem oil. The cytotoxicity tests indicated that leaf oil was more active than stem oil, resulting from the presence of biologically active sesquiterpenes that inhibit the growth of cancer cells.

Adiponectin, HOMA-Adiponectin, HOMA-IR in Children and Adolescents: Ouro Preto Study.

OBJECTIVES: To examine the association and predictive capacity of adiponectin levels, HOMA-AD and HOMA-IR indexes with metabolic risk markers in children and adolescents. METHODS: A cross-sectional study was conducted with 691 children and adolescents (7-14 y), of both sexes. Demographic (sex, age), anthropometric (weight, height, body mass index, waist circumference, body fat), biochemical [total cholesterol, high density lipoprotein (HDL), low density lipoprotein (LDL), triglycerides, fasting glycemia, insulin and adiponectin] and clinical parameters (arterial blood pressure) were analyzed. RESULTS: In multiple linear regression models, metabolic risk were analyzed in relation to adiponectin levels, HOMA-AD and HOMA-IR. ROC curve analysis was used to define the cut-off for metabolic syndrome for each method studied. Adiponectin level was inversely correlated with weight (r = -0.12; p = 0.01), waist circumference (WC) (r = -0.12; p = 0.01), and triglycerides (r = -0.11; p = 0.02); it was directly correlated with HDL (r = 0.10; p = 0.03) only in the adolescents. In the final linear regression model, after adjustment, only triglycerides (p = 0.03) and HDL (p = 0.04) remained significant. However, HOMA-AD and HOMA-IR were associated with metabolic risk and were the most suitable methods for metabolic syndrome screening in both age groups. For children, independent variables explained 16.0% and 14.5% of HOMA-AD and HOMA-IR, respectively. For adolescents, R2 was higher in HOMA-AD and HOMA-IR models (R2adjusted = 31.9% and R2adjusted = 29.6%, respectively). CONCLUSIONS: HOMA-AD and HOMA-IR are better explained by metabolic markers than adiponectin levels.

High levels of chemerin associated with variants in the NOS3 and APOB genes in rural populations of Ouro Preto, Minas Gerais, Brazil.

Chemerin is an adipokine that has been associated with components of metabolic syndrome. It has been described to affect adipocyte metabolism and inflammatory responses in adipose tissue, as well as the systemic metabolism of lipids and glucose. Few epidemiological studies have evaluated classical and genetics cardiovascular risk factors (CVRFs) in the mixed adult rural population in Brazil. Therefore, the present study explored possible associations between CVRFs and chemerin. This cross-sectional study included 508 adults from the rural localities of Lavras Novas, Chapada, and Santo Antônio do Salto in Ouro Preto, Minas Gerais, Southeast Brazil. Demographic, behavioral, clinical, biochemical, anthropometric variables, and 12 single nucleotide polymorphisms (SNPs) linked with metabolic syndrome phenotypes were evaluated for associations with chemerin level. There was a significant association of high triglyceride levels [odds ratio (OR)=1.91, 95%CI: 1.23-2.98], insulin resistance (OR=1.82, 95%CI: 1.03-3.22), age (OR=1.64, 95%CI: 1.08-2.49), and sex (OR=1.99, 95%CI: 1.35-2.95) with high levels of chemerin. High chemerin levels were significantly associated with the genetic polymorphisms rs693 in the APOB gene (OR=1.50, 95%CI: 1.03-2.19) and rs1799983 in the NOS3 gene (OR=1.46, 95%CI: 1.01-2.12) for the AA and GT+TT genotypes, respectively. In the concomitant presence of genotypes AA of rs693 and GT+TT of rs1799983, the chance of presenting high levels of chemerin showed a 2.21-fold increase (95%CI: 1.25-3.88) compared to the reference genotype. The development of classical CVRFs in this population may be influenced by chemerin and by two risk genotypes characteristic of variants in well-studied genes for hypertension and dyslipidemia.

Size distributions of cadmium sulfide nanoparticles obtained from templating methods.

Cadmium sulfide (CdS) nanoparticles were obtained by soft templating methods using either an already established revered micelle route or a new procedure based on gel electrophoresis. The UV-Vis absorption or the photoluminescence excitation spectra were fitted using the CdS electronic structure available in the literature together with a size distribution. The obtained results indicate that the amount of sodium dodecyl sulphate as a component of the agarose gel formulation has a profound effect on the resulting nanoparticle population.

Neural correlates of risk perception as a function of risk level: An approach to the study of risk through a daily life task.

We are often required to make decisions that can have safe or risky consequences. Evaluating the risk of each possible alternative is an important step before making our final decision. The main goal of the present research was to explore the neural basis of risk perception in a naturalistic context (driving). Twenty-two drivers evaluated the perceived risk in 72 traffic situations (previously categorized by driving instructors) while brain activity was recorded using fMRI. A neural network involving attentional factors, emotional processing, stimulus-response associations, and risk aversion was related to the perception of risks. Given the nature of our task, a more prominent role was played by emotional factors (evaluation of the consequences) than cognitive factors (e.g. probabilistic calculations). Moreover, activation in the insula, inferior frontal gyrus, precentral/postcentral gyrus, inferior parietal gyrus, and temporal and occipital regions linearly increased as a function of risk level. Our findings provide a new step towards understanding the neural processing underlying risk behavior in daily life tasks, which is particularly relevant given the study context and its important practical implications for our society.

Neuroanatomical variations as a function of experience in a complex daily task: A VBM and DTI study on driving experience.

Complex tasks require the learning and integration of multiple cognitive, sensory, and psychomotor skills for correct execution. Driving-related skills are developed step by step through the increase of mileage driven and the accumulation of practice in different traffic situations. The acquisition of these skills should be reflected in the brain structure. However, no previous studies have explored brain structural variations associated with driving experience. The aim of the present study was to investigate whether driving frequency, defined as average annual driving mileage, is related to neuroanatomical variations in gray matter (GM) volume and white matter (WM) integrity using voxel-based morphometry (VBM) and DTI-based fractional anisotropy (FA), respectively. We recruited 83 drivers with variable range of annual driving mileage and controlled for age, sex, handedness, IQ, time since the acquisition of driving license, use of motorcycles/mopeds and bicycles, perceived driving skills, and subjective probability of having an accident. Our results showed variations in white matter FA as a function of mileage driven. Driving experience was related to a significant increase of FA in parts of the right hemisphere superior and inferior longitudinal fasciculus, anterior thalamic radiation, forceps majors, inferior fronto-occipital fasciculus, and corticospinal tract. No significant differences were observed in gray matter volumes. FA variations were found in brain regions that have been associated with cognitive, visual, and motor processes necessary for skilled performance in driving. These results suggest that variations in white matter diffusivity can underlie the development of driving skills and safer driving.

Chemical composition, in vitro larvicidal and antileishmanial activities of the essential oil from Citrus reticulata Blanco fruit peel

Abstract Numerous studies have investigated the chemical composition and biological activities of essential oils from different Citrus species fruit peel, leaves and flowers. This paper aims to investigate the chemical composition, larvicidal and antileishmanial activities of essential oil from Citrus reticulata fruit peel (CR-EO). CR-EO was obtained by hydrodistillation in a Clevenger-type apparatus and its chemical composition was analyzed by GC-MS and GC-FID. Limonene (85.7%), -terpinene (6.7%) and myrcene (2.1%) were identified as its major components. CR-EO showed high activity against promastigote forms of Leishmania amazonensis (IC50 = 8.23 µg/mL). CR-EO also exhibited high larvicidal activity against third instar Aedes aegypti larvae at a lethal concentration (LC50 = 58.35 µg/mL) and 100% mortality at 150 µg/mL. This study suggests, for the first time, the potential use of CR-EO against this important mosquito-borne viral disease caused by the genus Aedes.

Resumo Numerosos estudos têm investigado a composição química e as atividades biológicas de óleos essenciais extraídos de cascas dos frutos, folhas e flores de diferentes espécies de Citrus. Este trabalho tem como objetivo investigar a composição química e as atividades larvicida e leishmanicida in vitro do óleo essencial das cascas dos frutos de Citrus reticulata (CR-EO). CR-EO foi obtido pela técnica de extração em aparelho Clevenger e sua composição química foi determinada por CG-EM e CG-DIC. Limoneno (85,7%), -terpineno (6,7%) and mirceno (2,1%) foram identificados como os constituintes majoritários. CR-EO mostrou alta atividade contra as formas promastigota de Leishmania amazonensis (CI50 = 8,23 µg/mL). CR-EO também exibiu alta atividade larvicida contra as larvas do terceiro estágio do Aedes aegypti com concentração letal (CL50 = 58,35 µg/mL) e mortalidade de 100% em 150 µg/mL. Este estudo sugere, pela primeira vez, o uso potencial de CR-EO contra esta importante doença viral transmitida por mosquitos do gênero Aedes.

Chemical composition, in vitro larvicidal and antileishmanial activities of the essential oil from Citrus reticulata Blanco fruit peel / Composição química, atividades larvicida e leishmanicida in vitro do óleo essencial da casca do fruto de Citrus reticulata Blanco

Abstract Numerous studies have investigated the chemical composition and biological activities of essential oils from different Citrus species fruit peel, leaves and flowers. This paper aims to investigate the chemical composition, larvicidal and antileishmanial activities of essential oil from Citrus reticulata fruit peel (CR-EO). CR-EO was obtained by hydrodistillation in a Clevenger-type apparatus and its chemical composition was analyzed by GC-MS and GC-FID. Limonene (85.7%), ɣ-terpinene (6.7%) and myrcene (2.1%) were identified as its major components. CR-EO showed high activity against promastigote forms of Leishmania amazonensis (IC50 = 8.23 µg/mL). CR-EO also exhibited high larvicidal activity against third instar Aedes aegypti larvae at a lethal concentration (LC50 = 58.35 µg/mL) and 100% mortality at 150 µg/mL. This study suggests, for the first time, the potential use of CR-EO against this important mosquito-borne viral disease caused by the genus Aedes.

Resumo Numerosos estudos têm investigado a composição química e as atividades biológicas de óleos essenciais extraídos de cascas dos frutos, folhas e flores de diferentes espécies de Citrus. Este trabalho tem como objetivo investigar a composição química e as atividades larvicida e leishmanicida in vitro do óleo essencial das cascas dos frutos de Citrus reticulata (CR-EO). CR-EO foi obtido pela técnica de extração em aparelho Clevenger e sua composição química foi determinada por CG-EM e CG-DIC. Limoneno (85,7%), ɣ-terpineno (6,7%) and mirceno (2,1%) foram identificados como os constituintes majoritários. CR-EO mostrou alta atividade contra as formas promastigota de Leishmania amazonensis (CI50 = 8,23 µg/mL). CR-EO também exibiu alta atividade larvicida contra as larvas do terceiro estágio do Aedes aegypti com concentração letal (CL50 = 58,35 µg/mL) e mortalidade de 100% em 150 µg/mL. Este estudo sugere, pela primeira vez, o uso potencial de CR-EO contra esta importante doença viral transmitida por mosquitos do gênero Aedes.