Avaliação de atividades farmacológicas de diferentes espécies de Lychnophora utilizadas pela população.

The Lychnophora genus species are native plants from Brazil, popularly known as “arnica” and used in the folk medicine as analgesic and anti-inflammatory. The antinociceptive activity of the etanolic extracts of six species of Lychnophora were evaluated in the hot-plate test and in the acetic acid-induced writhing test and the antiinflammatory topical activity were evaluated in the carrageenan-induced paw oedema test. In the hot-plate test the etanolic extracts of L. pinaster (0.75 g/kg) and L. ericoides (1.50 g/kg), significantly increased the variation of the latency time for licking of the paws. The extracts of L. passerina, L. candelabrum and L. pinaster in the dose 0.75 g/kg and of L. ericoides and L. trichocarpha in both doses evaluated (0.75 and 1.50 g/kg) significantly decreased the number of writhes induced by acetic-acid. The topical administration of L. pinaster and L. trichocarpha in both concentrations evaluated (5 and 10%) and of L. passerina and L. candelabrum 10%, significantly reduced the paw oedema measured 3 h after the subplantar injection of carrageenan 0.1%, evidencing for the first time the anti-inflammatory activity of the topical administration of Lychnophora species. The method of measurement of the paw oedema using a pakimeter were validated and showed that the pakimeter is so effective how the plethysmometer to measure the paw oedema induced by carrageenan. The effects of the extracts of L. ericoides and L. trichocarpha were evaluated before, 1, 2, 4 and 24 h after the oral administration, in the open-field test, that evaluate the locomotor and exploratory activities and in the rota-rod and traction tests, wich evaluate the motor coordination and the muscular tone of the animals, respectively. In the open-field test, the extract of L. ericoides (1.50 g/kg) in 1 h and the extract of L. trichocarpha in the dose 0.75 g/kg in 2 h and in the dose 1.50 g/kg in the times 1, 2 and 4 h induced to significant inhibition of the spontaneous locomotor activity of the animals evidenced by the reduction of the number of squares crossed in 5 min. The extracts of L. ericoides (0.75 g/kg) in 24 h and of L. trichocarpha in the dose 0.75 g/kg in 2 h and in the dose 1.50 g/kg in the times 1, 2 and 4 h induced to the decrease of the exploratory behavior of the animals, evidenced by the significant decrease of the number of times that the animal raises in 5 min. The decrease of the spontaneous locomotion and the exploratory behavior induced by the administration of these extacts Abstract compared to the control group were indicative of sedative effect. The extracts of L. ericoides and L. trichocarpha in both doses (0.75 and 1.50 g/kg) and in all times evaluated did not induce significant modification of the motor coordination and the muscular tone of the animals. Beyond the evaluation of the activity on the SNC, in the present study to better establish the therapeutical security of the L. ericoides ethanolic extract, the specie most used by the population, its cardiovascular activity was evaluate from 90 to 120 min after its administration by oral route. The results demonstrated that the L. ericoides extract in the dose 1.50 g/kg increased the systolic and diastolic arterial pressure and the heart rate of the animals. The present work demonstred comparatively the antinociceptive and antiinflammatory activities of six species of Lychnophora, the sedative activity of L. ericoides and L. trichocarpha species and the hypertensive and cronotropic positive activities of L. ericoides in the higher dose evaluated, giving cientific knowledge for the rational and directed use of the species studied in the folk medicine.