A janaúba (Himatanthus spp.), ocorre em populações naturais em ecossistemas florestais e apresenta amplo espectro de usos na medicina popular que vai desde o tratamento de inflamações uterinas, gastrite, uso veterinário, complemento alimentar, até tratamento de câncer. O extrativismo de látex de janaúba em Alcântara vem adquirindo importância crescente como alternativa de renda. Sendo assim, o estabelecimento de estudos que viabilizem o manejo sustentado em seu ambiente natural é necessário. O objetivo deste trabalho foi de caracterizar os ambientes de ocorrência de Himatanthus no município de Alcântara, Maranhão, Brasil, e identificar a flora acompanhante. As amostragens foram definidas por indicação de informantes, e aparente frequência na comunidade vegetal; os ambientes foram descritos considerando as unidades de paisagem e histórico de uso. Como resultados, a maior área de ocorrência foi a terra firme seguida por várzeas de restinga; a principal tipologia vegetacional foi a mata secundária. O bacuri (Platonia insignis Mart.), tucum (Astrocaryum vulgare Mart.) e a murta verdadeira (Myrcia selloi (Spreng.) N. Silveira, foram às principais espécies associadas.

The Frangipani (Himatanthus spp.) occur in natural populations in forest ecosystems and present a wide spectrum of uses. in folk medicine ranging from the treatment of uterine inflammation, gastritis, veterinary, food supplement to medicinal treatment of cancer. The extraction of latex Janaúba Alcantara has been gaining increasing importance as an alternative income. Therefore, the establishment of studies that enable sustainable management in their natural environment is necessary. The overall objective of this study was to characterize the occurrence of Himatanthus environments in the municipality of Alcântara, Maranhão, Brazil, and identify the accompanying vegetation. The samples were defined by word of informants, and apparent frequency in the plant community, the environments were described considering the landscape units and usage history. As a result, the largest area of occurrence was followed by the mainland salt marsh wetlands, the main vegetation type was the secondary forest. Bacuri (Platonia insignis Mart.), tucum (Astrocaryum vulgare Mart.) e murta verdadeira (Myrcia selloi (Spreng.) N. Silveira, were the main species associated.

Identificaram-se e caracterizaram-se a resistência e a multirresistência aos principais antimicrobianos usados no tratamento de mastite bovina causada por Escherichia coli. A concentração inibitória mínima (MIC) e o sistema de efluxo foram detectados pelas curvas de crescimento, com base na densidade óptica, em diferentes concentrações da droga e na presença e na ausência do desacoplador da força próton-motora (PMF). E. coli 1 foi resistente à neomicina e à gentamicina; E. coli 3 e 4, à tetraciclina e à estreptomicina; e E. coli 2 e 6 à gentamicina. E. coli 5 apresentou modelo de sensibilidade. Observou-se que MICs de todos os antimicrobianos dos multirresistentes (E. coli 1, 3 e 4) diminuíram na presença do desacoplador, o que sugere sistema de efluxo multidrogas. Após cura, apenas E. coli 1 apresentou modelo de sensibilidade, porém não houve alterações das MICs, antes e após adição do desacoplador. Os resultados indicam possível presença de mecanismo de resistência dependente da PMF codificado, ou parte dele, em plasmídeo.

Resistance and multiresistance to main antimicrobials used for treating bovine mastitis caused by Escherichia coli were identified and characterized. The minimal inhibitory concentration (MIC) and efflux systems were detected by the use of growth curves based on optical density at different drug concentrations and both presence and absence of uncoupler of the proton-motive force (PMF). E. coli 1 was resistant to neomycin and gentamycin, E. coli 3 and 4 were resistant to tetracycline and streptomycin, whereas E. coli 2 and 6 were resistant to gentamycin. E. coli 5 showed sensibility model. MICs of all antimicrobials of the multiresistant samples (E. coli 1, 3, and 4) were decreased in presence of the uncoupler, therefore suggesting the presence of the multidrug efflux system. After healing, only E. coli 1 showed sensibility model, however no alteration occurred in MIC(s) before and after adding the uncoupler. Those data inform the possible presence of a PMF dependent resistance mechanism that is totally or partly codified in plasmid.

Cytochrome P450 (CYP) 2A enzymes are involved in the metabolism of numerous drugs and hormones and activate different carcinogens. Human CYP2A6, mouse CYP2A5 and rat CYP2A3 are orthologous enzymes that present high similarity in their amino acid sequence and share substrate specificities. However, different from the human and mouse enzyme, CYP2A3 is not expressed in the rat liver. There are limited data about expression of CYP2A3 in extrahepatic tissues and its regulation by typical CYP inducers. Therefore, the objective of the present study was to analyze CYP2A3 mRNA expression in different rat tissues by RT-PCR, and to study the influence of 3-methylcholanthrene, pyrazole and ß-ionone treatment on its expression. Male Wistar rats were divided into four groups of 5 rats each, and were treated ip for 4 days with 3-methylcholanthrene (25 mg/kg body weight), pyrazole (150 mg/kg body weight), ß-ionone (1 g/kg body weight), or vehicle. Total RNA was extracted from tissues and CYP2A3 mRNA levels were analyzed by semiquantitative RT-PCR. CYP2A3 mRNA was constitutively expressed in the esophagus, lung and nasal epithelium, but not along the intestine, liver, or kidney. CYP2A3 mRNA levels were increased in the esophagus by treatment with 3-methylcholanthrene and pyrazole (17- and 7-fold, respectively), in lung by pyrazole and ß-ionone (3- and 4-fold, respectively, although not statistically significant), in the distal part of the intestine and kidney by 3-methylcholanthrene and pyrazole, and in the proximal part of the intestine by pyrazole. CYP2A3 mRNA was not induced in nasal epithelium, liver or in the middle part of the intestine. These data show that, in the rat, CYP2A3 is constitutively expressed in several extrahepatic tissues and its regulation occurs through a complex mechanism that is essentially tissue specific.