The transient potential vanilloid 1 receptor (TRPV1) is a calcium-permeable channel responsible for the transduction and modulation of acute and chronic pain signaling. As such, this receptor is a potential target for the treatment of a number of pain disorders. However, AMG517, a TRPV1 antagonist, presents several clinical limitations that include the induction of severe hyperthermia. The aim of this study was to investigate the possible interaction of the flavonoid eriodictyol with the TRPV1 receptor and to determine its putative antinociceptive and hyperthermic effects. Eriodictyol was able to displace [(3)H]-resiniferatoxin binding (IC(50)=47; 21-119nM) and to inhibit calcium influx mediated by capsaicin (IC(50)=44; 16-125nM), suggesting that eriodictyol acts as a TRPV1 antagonist. Moreover, eriodictyol induced antinociception in the intraplantar capsaicin test, with maximal inhibition of 49±10 and 64±4% for oral (ID(50)=2.3; 1.1-5.7mg/kg) and intrathecal (ID(50)=2.2; 1.7-2.9nmol/site) administration, respectively. Eriodictyol did not induce any change in body temperature or locomotor activity. Orally administered eriodictyol (4.5mg/kg) prevented the nociception induced by intrathecal injections of capsaicin, as well as the non-protein thiol loss and 3-nitrotyrosine (3-NT) formation induced by capsaicin in spinal cord. Eriodictyol also reduced the thermal hyperalgesia and mechanical allodynia elicited by complete Freund's adjuvant (CFA) paw injection. In conclusion, eriodictyol acts as an antagonist of the TRPV1 receptor and as an antioxidant; it induces antinociception without some of the side effects and limitations such as hyperthermia that are expected for TRPV1 antagonists.

Florestas estacionais semideciduais (FES) possuem alta heterogeneidade e diversos são os fatores contribuintes na variação estrutural e florística destas florestas. Assim, foi realizado o estudo da composição florística e da estrutura, horizontal e vertical, de uma comunidade arbórea de uma FES. A área se localiza nas coordenadas 18º29'28"S e 48º23'45"W. Demarcou-se um hectare de área, foram amostradas árvores com circunferência a 1,30 m > 15 cm e estimada a altura dos indivíduos. Calcularam-se os parâmetros fitossociológicos (densidade, dominância e freqüência relativas). As parcelas foram categorizadas quanto a porcentagem total de clareiras e as espécies foram classificadas quanto ao estratro vertical ocupado. As análises permitiram a classificação das espécies em grupos sucessionais. Amostraram-se 839 indivíduos e ocorreu predomínio de espécies secundárias tardias principalmente no sub-bosque, com pouca presença de pioneiras. Com base nas análises a floresta da Fazenda da Mata pode ser classificada como uma floresta em estágio primário de conservação.

The results of this study show that the extract of M. vulgare and marrubiin displays antiulcer activity and that this effect can be partly attributed to the isolated diterpene.

Palavras-chave: cerrado, murundu, vegetação, lençol freáticoABSTRACT -(Plant community and abiotic characteristics of a murundu field in Uberlândia, MG). Murundus are small usually round mounds, that often present soil and vegetation different from the surrounding level area. All micro-elevations incountered in a 1.08ha murundu field had their length, width and height measured. The depth of the water table was measured and soil characteristics were obtained within and outside the murundus. All woody plants (lianas, trees, and shrubs) with a diameter of ≥ 5 mm at ground level were identified. A total 434 elevations (31.4% of the total area) were encontered, of which 48 (24.3%) contained woody plants. The mound vegetation comprised 116 species belonging to 72 genera, and 42 families. The depth of the water table for those murunduns with woody plants varied between 99.2 and 206.8cm. The studied soil showed a low content of exchangeable bases, but only slight differences were observed between murundus and level soils. Matayba guianensis Aubl. and Erythroxylum suberosum A. St.-Hil. had the highest densities, while Copaifera langsdorffii Desf. and Blepharocalyx salicifolius (Kunth) O. Berg. showed the highest basal areas. The heigher diversity encountered here in comparison to other published reports may be due to cattle grazing and trampling as well as burning.