Ocellatin peptides from the skin secretion of the South American frog Leptodactylus labyrinthicus (Leptodactylidae): characterization, antimicrobial activities and membrane interactions

Background The availability of antimicrobial peptides from several different natural sources has opened an avenue for the discovery of new biologically active molecules. To the best of our knowledge, only two peptides isolated from the frog Leptodactylus labyrinthicus, namely pentadactylin and ocellatin-F1, have shown antimicrobial activities. Therefore, in order to explore the antimicrobial potential of this species, we have investigated the biological activities and membrane interactions of three peptides isolated from the anuran skin secretion. Methods Three peptide primary structures were determined by automated Edman degradation. These sequences were prepared by solid-phase synthesis and submitted to activity assays against gram-positive and gram-negative bacteria and against two fungal strains. The hemolytic properties of the peptides were also investigated in assays with rabbit blood erythrocytes. The conformational preferences of the peptides and their membrane interactions have been investigated by circular dichroism spectroscopy and liposome dye release assays. Results The amino acid compositions of three ocellatins were determined and the sequences exhibit 100% homology for the first 22 residues (ocellatin-LB1 sequence). Ocellatin-LB2 carries an extra Asn residue and ocellatin-F1 extra Asn-Lys-Leu residues at C-terminus. Ocellatin-F1 presents a stronger antibiotic potential and a broader spectrum of activities compared to the other peptides. The membrane interactions and pore formation capacities of the peptides correlate directly with their antimicrobial activities, i.e., ocellatin-F1 > ocellatin-LB1 > ocellatin-LB2. All peptides acquire high helical contents in membrane environments. However, ocellatin-F1 shows in average stronger helical propensities. Conclusions The obtained results indicate that the three extra amino acid residues at the ocellatin-F1 C-terminus play an important role in promoting stronger peptide-membrane interactions and antimicrobial properties. The extra Asn-23 residue present in ocellatin-LB2 sequence seems to decrease its antimicrobial potential and the strength of the peptide-membrane interactions.(AU)

Ocellatin peptides from the skin secretion of the South American frog Leptodactylus labyrinthicus (Leptodactylidae): characterization, antimicrobial activities and membrane interactions

Abstract Background The availability of antimicrobial peptides from several different natural sources has opened an avenue for the discovery of new biologically active molecules. To the best of our knowledge, only two peptides isolated from the frog Leptodactylus labyrinthicus, namely pentadactylin and ocellatin-F1, have shown antimicrobial activities. Therefore, in order to explore the antimicrobial potential of this species, we have investigated the biological activities and membrane interactions of three peptides isolated from the anuran skin secretion. Methods Three peptide primary structures were determined by automated Edman degradation. These sequences were prepared by solid-phase synthesis and submitted to activity assays against gram-positive and gram-negative bacteria and against two fungal strains. The hemolytic properties of the peptides were also investigated in assays with rabbit blood erythrocytes. The conformational preferences of the peptides and their membrane interactions have been investigated by circular dichroism spectroscopy and liposome dye release assays. Results The amino acid compositions of three ocellatins were determined and the sequences exhibit 100% homology for the first 22 residues (ocellatin-LB1 sequence). Ocellatin-LB2 carries an extra Asn residue and ocellatin-F1 extra Asn-Lys-Leu residues at C-terminus. Ocellatin-F1 presents a stronger antibiotic potential and a broader spectrum of activities compared to the other peptides. The membrane interactions and pore formation capacities of the peptides correlate directly with their antimicrobial activities, i.e., ocellatin-F1 > ocellatin-LB1 > ocellatin-LB2. All peptides acquire high helical contents in membrane environments. However, ocellatin-F1 shows in average stronger helical propensities. Conclusions The obtained results indicate that the three extra amino acid residues at the ocellatin-F1 C-terminus play an important role in promoting stronger peptide-membrane interactions and antimicrobial properties. The extra Asn-23 residue present in ocellatin-LB2 sequence seems to decrease its antimicrobial potential and the strength of the peptide-membrane interactions.

Cytotoxicity of latex and pharmacobotanical study of leaves and stem of Euphorbia umbellata (Janaúba)

AbstractIn southern Brazil, the bottled latex of Synadenium grantii Hook f., Euphorbiaceae, is popularly used as a treatment of all types of cancer. Similarly, Synadenium umbellatum Pax. is used in the central western region of Brazil for the same purpose and in the same manner of use. Both plants are popularly known as janaúba or leitosinha. The objectives of this study were to use pharmacobotanical analysis to verify whether these two species, which are considered to be distinct, are actually the same to determine anatomical markers; to assist in the identification and differentiation of other Euphorbia; and to evaluate the cytotoxic activity of the latex in relation to HeLa and HRT-18 cells. Leaves and stems of the species were collected in Goiânia and Ponta Grossa and were investigated using scanning electron microscopy and optical microscopy techniques. The latex was also collected and analyzed in relation to its cytotoxic effect by employing MTT and NR techniques. The pharmacobotanical study of the specimens in both localities showed that they were the same species, namely Euphorbia umbellata (Pax) Bruyns, which is the scientific nomenclature accepted and confirmed by an expert taxonomist who specializes in Euphorbia. The pharmacobotanical characteristics highlighted in this study can assist in the identification of the taxon and contribute to the control of the quality of this plant drug. The evaluation of the latex in relation to HRT-18 cells demonstrated action after 48 h of experiment. In contrast, in relation to HeLa cells its induced cytotoxicity in all times and a dose-dependent manner. The IC50 values (72 h) observed were 252.58 ± 18.51 µg/ml and 263.42 ± 15.92 µg/ml to MTT experiment and 250.18 ± 19.48 µg/ml and 430.56 ± 19.71 µg/ml to NR experiment for the HeLa and HRT-18 cells, respectively.

Anatomical investigations of Piper amalago (jaborandi-manso) for the quality control

Abstract Piper amalago L., Piperaceae, popularly known as jaborandi-manso, is a shrub that spans a height of 2–7 m. It can be found in the regions of Southern America downward up to the south of Brazil. Traditionally it is used to treat digestive problems, heart problems, and burns. This study aims to conduct an anatomical investigation and analysis of the leaves and stems of P. amalago through electron scanning and optical micro techniques. The analysis showed that P. amalago has a hypostomatic leaf, with a subepidermal layer on its surface. There are grandular trichomes that resemble sacs, conic non-glandular trichomes, dorsiventral mesophyll, and a plano-convex midrib having a single vascular bundle in the center. The petiole is short with irregularly shaped and adaxially grooved. The stem is circular in shape and contains two circles of vascular bundles and a sclerenchymatic sheath in the perimedular region. These anatomical features of the Piper amalago's leaves and stems make it easy to pick it out among other species of the Piper genus. This is helpful when conducting quality control process.

Epidemiological analysis of serological markers of hepatitis B in HIV+ patients from Curitiba and metropolitan region / Análise epidemiológica de marcadores sorológicos de hepatite B em pacientes HIV+ de Curitiba e região metropolitana

Introduction: The presence of hepatitis B virus (HBV) in patients infected by the human immunodeficiency virus (HIV) leads to a higher incidence of liver disorders due to persistence and recurrence of HBV infection in addition to increased morbidity and mortality. Objective: To determine the prevalence of serological markers for hepatitis B in patients infected by HIV followed at Hospital de Clínicas da Universidade Federal do Paraná (HC-UFPR). Methods: The clinical and epidemiological data were collected through a questionnaire applied to the patients, as well as a retrospective analysis of medical records. Serum levels of total hepatitis B core antibody (anti-HBc) and surface antigen of the hepatitis B virus (HBsAg) were evaluated through chemiluminescent microparticle immunoassay. Among the 297 HIV+ patients, 49.8% were seropositive only for anti-HBc, and 2.6 % were positive for both markers. Results and discussion: The prevalence of hepatitis B markers was significantly associated with HIV infection when compared with the prevalence observed in the general population from the same geographical area (anti-HBc+ HBsAg+: 0.14% vs. 2.6%, OR: 18.82, 95% CI 2.34-151.19, p = 0.00052). Concerning the associated risks to acquire HIV/HBV infection, 44.87% of the patients reported having been infected through sexual contact. A total of 16.66% HIV/HBV positive patients were in the age group 18-30 years, 62.82% were between 31-50 years and 16.66% were over 60 years old. Conclusion: The findings of the present study corroborate the need to investigate systematically the presence of markers for HBV in HIV+ patients from different regions of the country. .

Introdução: A presença do vírus da hepatite B (HBV) em indivíduos infectados pelo vírus da imunodeficiência humana (HIV) está associada ao significante aumento da morbimortalidade nos pacientes afetados. Objetivo: Estabelecer a prevalência de marcadores sorológicos de HBV e dos fatores epidemiológicos associados em pacientes HIV+ acompanhados pelo Hospital de Clínicas da Universidade Federal do Paraná (HC-UFPR). Métodos: Os dados clinicoepidemiológicos foram coletados por meio de análise retrospectiva dos prontuários e de aplicação de um questionário. Os marcadores anti-HBc total e o antígeno HbsAg foram avaliados pela quimioluminescência por micropartículas. Resultados e discussão: Dos 297 pacientes HIV+, 49,8% apresentaram sorologia positiva somente para anti-HBc e 2,6%, para anti-HBc e HbsAg. A prevalência de marcadores de hepatite B foi significantemente associada à infecção pelo HIV quando comparada com a prevalência observada na população geral da mesma área geográfica (anti-HBc+/HbsAg+: 0,14% vs. 2,6%, odds ratio (OR): 18,82, intervalo de confiança (IC) 95%: 2,34-151,19, p = 0,00052). Em relação aos grupos de risco para infecção pelo HIV, 44,87% dos pacientes com sorologia positiva para HBV informaram terem sido infectados por transmissão sexual. Quanto à faixa etária dos pacientes HIV+/HBV+, 16,66% tinham entre 18-30 anos, 62,82%, entre 31-50 anos e 16,66%, acima dos 50 anos de idade (p = ns). Conclusão: Esses achados corroboram a necessidade de se investigar sistematicamente a presença de marcadores para HBV em pacientes HIV+ das diferentes regiões do país. .

Qualidade de vida de crianças ostomizadas na ótica das crianças e das mães / Quality of live of children with stomas: the children and mothers' point of view

Objetivos: analisar a qualidade de vida de crianças ostomizadas em sua ótica e na de suas mães; comparar os escores de qualidade de vida (QV) obtidos em ambos grupos (crianças e mães), e verificar as associações entre os escores de qualidade de vida e as característicassociodemográficas e clínicas das crianças. Métodos: após o cumprimento das exigências éticas, os dados sobre a qualidade de vida foram obtidos através do Autoquestionnaire Qualité de Vie Enfant Imagé (AUQEI), em sua versão traduzida para a língua portuguesa, adaptada por Assumpção et al. e validada para este estudo. O questionário foi respondido por 20 crianças ostomizadas, oriundas de um serviço público infantil de referência do Município de São Paulo e por suas respectivas mães. Os dados obtidos foram submetidos ao teste de normalidade de Kolmogorov-Smimov, coeficientes de correlação ordinal de Spearman e de correlação linear de Pearson, e o teste t de student. Resultados: dez meninos e 10 meninas, com idades entre 4 e 12 anos, apresentaram idade média de 8,7 anos (DP=2,64), com predomínio da raça branca (55 por cento) e da escolaridade fundamental (65 por cento). Clinicamente, predominaram os estomas urinários (55 por cento), proveni-entes, principalmente, das mal formações congênitas (60 por cento). Com relação à qualidade de vida, obtiveram-se escores médios totais de 51,95 (DP = 7,90) e 49,60 (DP = 5,60), apontados, respectivamente, pelas crianças e mães. Quanto aos fatores, os escores obtidos pelas crianças foram 8,14; 8,29; 10,27 e II, 41, respectivamente, paraautonomia, lazer, funções e família. Correlações...