Problemas associados ao uso de plantas medicinais comercializadas no Mercadão de Madureira, município do Rio de Janeiro, Brasil / Problems associated with the use of medicinal plants commercialized in "Mercadão de Madureira", Rio de Janeiro City, Brazil

O uso de plantas medicinais pela população brasileira é prática tradicional, sendo muitas vezes o único recurso utilizado na atenção básica de saúde. O uso terapêutico dessas plantas envolve várias etapas da cadeia produtiva, sendo a procedência, coleta, secagem, armazenamento, comércio, modo de preparo pelo usuário e uso. O objetivo desse trabalho documental, de caráter exploratório, foi levantar a produção científica existente sobre os problemas associados a cada uma dessas etapas e discutir as questões relacionadas à carência de estudos para comprovar a eficácia farmacológica e a ausência de riscos toxicológicos, bem como a prática de autodiagnóstico. As vinte plantas mais comercializadas em grande mercado do município do Rio de Janeiro em agosto de 2007 serviram de base para o levantamento documental do presente estudo. Dessas, seis apresentaram propriedades tóxicas comprovadas dependendo do preparo e uso, a arnica (Solidago chilensis Meyen), aroeira (Shinus terebinthifolius Raddi.), arruda (Ruta graveolens L.), babosa (Aloe vera L.), confrei (Symphytum officinale L.) e poejo (Mentha pulegium Lam. & DC.). A Agência Nacional de Vigilância Sanitária aponta contra indicações para boldo-do-Chile (Peumus boldus Molina), chapéu-de-couro (Echinodorus macrophyllus Micheli), erva-cidreira (Lippia alba N.E.Br.), erva-de-bicho (Polygonum spp.), espinheira-santa (Maytenus spp.), picão (Bidens pilosa L.), poejo (Mentha pulegium Lam.) e tanchagem (Plantago major L.). O abajerú, arnica, boldo-do-Chile, confrei, erva-de-bicho e espinheira-santa tiveram relato de problemas de identificação na coleta e comercialização frente a outras morfologicamente semelhantes. Plantas cultivadas e silvestres apresentam variabilidade de princípios ativos influenciados por fatores ambientais e genéticos, como chapéu-de-couro (Echinodorus macrophyllus Micheli), erva-cidreira (Lippia alba N.E.Br.) e erva-de-bicho (Polygonum spp.). A contaminação e o comprometimento da preservação dos princípios ativos pela secagem e armazenamento inadequados foram relatados para o guaco (Mikania glomerata Sprengel), camomila (Chamomilla recutita L.), erva-cidreira, chapéu-de-couro e boldo-do-Chile (Peumus boldus Molina). Pode-se constatar que todas as etapas da cadeia produtiva das plantas medicinais apresentam desafios para que se possa garantir identificação da espécie, disponibilidade, qualidade, segurança e eficácia de uso.

The use of medicinal plants by the Brazilian population is a traditional practice and is often the main resource used in primary healthcare. The therapeutic use of these plants involves several steps in the supply chain: origin, harvest, drying, storage, form of preparation by the user and use. The aim of this documental study of exploratory nature was to survey the scientific literature about the problems associated with each of those steps and discuss the issues related to the lack of studies to prove the pharmacological efficacy and the absence of toxicological risks, as well as the autodiagnosis practice. The 20 plants most commercialized in a large market of Rio de Janeiro City in August 2007 were the basis for the documental survey of the present study. Of these, six had proven toxic properties depending on their preparation and use: arnica (Solidago chilensis Meyen), aroeira (Shinus terebinthifolius Raddi.), rue (Ruta graveolens L.), "babosa" (Aloe vera L.), comfrey (Symphytum officinale L.) and pennyroyal (Mentha pulegium Lam. & DC.). The National Agency for Sanitary Surveillance shows contraindications for: "boldo-do-Chile" (Peumus boldus Molina), "chapéu-de-couro" (Echinodorus macrophyllus Micheli), lemon balm (Lippia alba N.E.Br.), "erva-de-bicho" (Polygonum spp.), "espinheira-santa" (Maytenus spp.), "picão" (Bidens pilosa L.), pennyroyal (Mentha pulegium Lam.) and plantain (Plantago major L.). "Abajerú", arnica, "boldo-do-Chile", comfrey, "erva-de-bicho" and "espinheira-santa" were reported to show identification problems in the harvest and in the commercialization compared to morphologically similar plants. Cultivated and wild plants showed variability in active principles influenced by environmental and genetic factors: "chapéu-de-couro" (Echinodorus macrophyllus Micheli), lemon balm (Lippia alba N.E.Br.) and "erva-de-bicho" (Polygonum spp.). Contamination and compromising of the preservation of active principles due to inadequate drying and storage was reported for guaco (Mikania glomerata Sprengel), camomile (Chamomilla recutita L.), lemon balm, "chapéu-de-couro" and "boldo-do-Chile" (Peumus boldus Molina). All stages of the supply chain of medicinal plants constitute challenges to ensure the proper species identification, availability, quality, safety, and efficacy of their use.

Technical improvement to prevent DNA degradation of Leptospira spp. in pulsed field gel electrophoresis.

Leptospirosis is a public health problem. Infection with pathogenic Leptospira occurs by exposure to many environments and is traditionally associated with occupational risk activities. Pulsed-field gel electrophoresis was used to investigate the epidemiological relatedness among Leptospira isolates. However, analysis by PFGE yielded inconclusive data as a result of extensive DNA degradation. This degradation can be significantly reduced by the inclusion of thiourea in the electrophoresis buffer, improving the analysis of DNA banding patterns.

Genetic diversity and antibiotic resistance of clinical and environmental Vibrio Cholerae suggests that many serogroups are reservoirs of resistance.

Vibrio cholerae is an important human pathogen and the cause of cholera. Since genetic variation and antibiotic resistance of strains have implications for effective treatment of the disease, we examined the genetic diversity and antibiotic resistance profile in 92 clinical strains (serogroup O1) and 56 environmental strains (O1 antigen, 42 strains; non-O1 antigen, 14 strains) isolated in Brazil between 1991 and 1999. Clinical and environmental O1 strains showed greater drug resistance compared to environmental non-O1 strains. Nearly all clinical O1 strains were resistant to one or more antibiotics while half of the environmental O1 and non-O1 strains were resistant to one or more antibiotics. No plasmids or class 1 integrons were detected in the strains by PCR analysis. Multilocus enzyme electrophoresis analysis (MLEE) suggests most of the O1 strains belong to a single (South American) clone that is related but different to seventh-pandemic strains isolated from other parts of the world. Our results show that there is a close genetic relationship between clinical and environmental O1 strains and that many serogroups and the environment can be a reservoir for antibiotic resistance.

Determinants of resistance in Bacteroides fragilis strains according to recent Brazilian profiles of antimicrobial susceptibility.

Susceptibility profiles of 99 Bacteroides fragilis strains for 9 antimicrobial agents were defined by using an agar dilution method. The isolates were uniformly susceptible to imipenen and metronidazole. All isolates were resistant to ampicillin. The resistance rates to amoxicillin/clavulanate, cefoxitin, cefotaxime, chloramphenicol, clindamycin and tetracycline were 3.0, 12.1, 15.1, 1.0, 18.2 and 75.7%, respectively. Sixteen strains showed reduced susceptibility to metronidazole (MIC 2-4 mg/L) but none had nim genes using PCR. All strains were also investigated for the presence of cepA, cfiA, cfxA, ermF and tetQ genes by PCR methodology and 92.9, 4.9, 24.2, 2 and 64.6% of the strains were respectively found positive. These results reflect the importance of surveys of susceptibility profiles and the relevance of detecting major genetic determinants to monitor the dissemination of these genes.

Antimicrobial resistance of strains of the Bacteroides fragilis group isolated from the intestinal tract of children and adults in Brazil.

The results of this study show that there is a high frequency of resistant species in the Bacteroides fragilis group in the intestinal tract of children and adults in Brazil. B. fragilis was not studied. Of the 73 strains examined, B. distasonis was the most resistant species to penicillin, cefoxitin, cefotaxime and clindamycin. High rates of multiresistance were found, most commonly to penicillin and clindamycin (18 of 36 strains). High levels of beta-lactamase production were detected in isolates showing high resistance to penicillin and multiresistance to the cephamycins, suggesting a widespread dissemination of such resistance.

Resistance profile of Bacteroides fragilis isolated in Brazil. Do they shelter the cfiA gene?

The epidemiology of antimicrobial resistance of clinical isolates and human intestinal strains of Bacteroides fragilis has assumed great importance in the last few years since this microorganism, like other members of the B. fragilis group, can be responsible for the spread of resistance determinants. It is possible that the presence of B. fragilis in polluted aquatic environments might contribute to the spread of resistance. The antimicrobial resistance profile of 44 clinical B. fragilis strains isolated from 1981-1988 and 1991-1998 from the University hospital of Rio de Janeiro, and of 17 faecal and 17 polluted aquatic environmental B. fragilis strains isolated between 1991 and 1998 was determined. The susceptibility tests against penicillin, cefoxitin, imipenem, meropenem, clindamycin, chloramphenicol and metronidazole were performed by Etest in Wilkins-Chalgren agar enriched with 5% sheep blood. Motivated by some high MIC values for cefoxitin and meropenem, the cfiA gene, which codes for a metallo-beta-lactamase, was investigated among all strains, using PCR amplification. The resistance to penicillin was high in the samples from 1981 to 1988 (92.9%) and also in those from 1991 to 1998 (100%), although the MIC90 decreased from 256 mg/L to 24 mg/L. An increase in the resistance level to clindamycin and cefoxitin was seen from one decade to the other, the MIC90 values changing from 4 mg/L to 12 mg/L and from 8 mg/L to 32 mg/L, respectively. The susceptibility profile for metronidazole, chloramphenicol, imipenem and meropenem remained stable, although two clinical strains showed MICs of 6 mg/L and 8 mg/L against meropenem. Almost all human intestinal strains were resistant to penicillin and all of them were susceptible to imipenem, meropenem, chloramphenicol and metronidazole. The MICs of meropenem against two strains isolated from a polluted aquatic environment were 6 mg/L and 32 mg/L. The cfiA gene was detected in five strains, two of which were isolated from clinical specimens against which the MIC values of cefoxitin were high and three from an aquatic environment, whose susceptibility to both cefoxitin and meropenem ranged from sensitive to resistant.

Production of bacteriocin by Bacteriodes fragilis and partial characterization.

The ability of Bacteroides fragilis strains, isolated from various sources, to produce bacteriocin was evaluated. All strains isolated from intestinal infections were producers in high levels and less susceptible to the others. Strains from other origins were found to produce bacteriocin at a medium level and they were variably susceptible. Some properties of one bacteriocin produced by the Bact. fragilis 079298-3 strain were analysed, providing evidence of its protein nature, with stability over a wide range of pH and retained inhibitory activity after heating. This variability seems to suggest that bacteriocin typing is a good method for this species.

Electrophoretic characterization of exposed outer membrane proteins in environmental and human Bacteroides fragilis strains.

Bacteriodes fragilis isolated from aquatic environment, from infectious process and from human feces were compared as to their outer membrane protein electrophoretic profiles after staining with Coomassie blue and reacting with antibodies prepared against whole-cell antigens of a reference strain from a clinical source. A marked homogeneity was found among the strains with these methodologies. The profiles of all strains obtained after radio-iodination of the intact cell showed qualitative similarity when compared with the profiles obtained by the other methods. Thus, these data allow us to suggest the designation of the peptides observed in the autoradiograms as surface-exposed proteins. Differences observed in the autoradiograms in the expression of bands mainly detected at a molecular weight of 28 in the commensal strain 118,310 defined previously as avirulent, in addition to a distinction in the titres of agglutination with the sera tested and lower reactivity in the immunoblotting assays, suggest a relationship of the B. fragilis surface architecture with the virulence potential as well as with the origin of the strain.

Influence of stress conditions on Bacteroides fragilis survival and protein profiles.

Bacteroides fragilis strains isolated from different sources, i.e. 1 strain (AA1) from an aquatic environment, 1 strain from normal flora (118310) and the type strain (ATCC 25285) originally isolated from clinical material, were analysed for both cell envelope proteins composition and surviving under oxidative stress starvation. All strains examined showed a similar survival response when cultured in drinking water with a ten-fold decrease in viable counts per day during the 7 days of analysis. The outer membrane protein (OMP) profiles of all strains were quite similar during the stress period as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). However, the periplasmic proteins of the strain 118310 showed two protein bands at 48 and 58 kDa, respectively, that were absent in the strains AA1 and ATCC 25285 during the incubation period in potable water. Whole cells and periplasmic 35S-labelled proteins from bacteria cultured in drinking water showed a significant increase in proteins at 16, 18, 24, 26, 35, 48, and 58 kDa and 18, 22, 24, 48, 58, and 70 kDa, respectively, in all strains when compared to cells grown in BHI-PRAS media as detected by autoradiography following SDS-PAGE. These data suggest that B. fragilis may have a synthesis mechanism that allows them to adapt to adverse environments.

Whole-cell and periplasmic protein banding patterns of environmental and human Bacteroides fragilis strains.

In order to investigate the relationship among virulent and avirulent Bacteroides fragilis strains, SDS-PAGE of whole-cell proteins (WP) and periplasmic proteins (PP) were used to establish a protein profile of strains isolated from human infections, fecal flora and environmental water. Despite different sources of the strains, no significant differences were observed as determined by the WP SDS-PAGE analysis. In contrast, the proteins obtained from the bacterial periplasm showed differences in the electrophoretic protein profile. Two distinct PP profile patterns were obtained. Pattern A included 6 out of the 8 virulent strains and pattern B, 6 out of 8 avirulent strains. Interestingly, an environmental strain that was capable of inducing abscesses in mice, had a PP profile highly similar to that of the virulent strains from human infections. These data indicate that PP from B. fragilis may be useful to characterize differences among virulent and avirulent strains. Moreover, strains isolated from environmental water may also be a source of exogenous infections by B. fragilis.

Surface vesicles: a possible function in commensal relations of Bacteroides fragilis.

Surface vesicles (SV) defined by electron microscopy as outer membrane (OM) extrusions were detected in Bacteroides fragilis strains from distinct sources. A partial identity between SV and OM electrophoretic protein profiles, in addition to the microscopic analysis, may suggest the designation of OMSV. Sialidase activity, a virulence determinant, was associated with these sub-cellular structures in all the strains, but in an inverse relation to the vesicle quantity per cell. A commensal strain, previously defined as avirulent in an animal model, presented the lowest vesicle-associated sialidase activity and the greatest SV expression as opposed to what happened with clinical and environmental strains. These results seem to suggest that these surface components have a function in commensal stages of B. fragilis.