Pharmacological activities investigation of crude extracts and fractions from Qualea grandiflora Mart.

This study investigates pharmacological activities of crude hydroalcoholic extract and fractions of Qualea grandiflora Mart. leaves employing different experimental models using mice. The treatment with crude hydroalcoholic extract (EH) in a dose of 500 mg/kg, i.p. caused: signs of central nervous system depressant action in the Hippocratic screening test, confirmed by the potentiation of sodium pentobarbital sleeping time. Increasing in the latency time of hot plate assay that indicate an analgesic effect; significantly delaying of the onset of clonic PTZ convulsions, increasing in the time for death, suppressing of the tonic PTZ convulsion, and decreasing of severity and number of convulsions. The median lethal dose of EH was 1.321 mg/kg. The convulsions induced by PTZ, ethyl ether fraction (300 mg/kg, i.p.) was more active in increasing the latency time for first convulsion, moreover, the hexane fraction, at the same dose, was more active in increasing the time for death and/or avoiding the death. Both did not cause disturbance in motor coordination at the dose of 500 mg/kg, assessed by rotarod test. These results suggest that the crude extract of leaves of Qualea grandiflora Mart. has a central nervous system depressant action, an analgesic effect and behave as a potential anticonvulsant.