Ageratina glabrata (Kunth) R.M. King & H. Rob., Asteraceae (syn. Eupatorium glabratum Kunth) is widely distributed throughout Mexico and popularly known as "chamizo blanco" and "hierba del golpe" for its traditional use as external analgesic remedy. Though glabrata species has been chemically studied, there are no experimentally asserted reports about possible analgesic effects which can be inferred from its genus Ageratina. To fill the gap, we evaluated A. glabrata extracts in an animal model of nociception exploiting thermal stimuli. NMR and mass analyses identified a new thymol derivative, 10-benzoiloxy-6,8,9-trihydroxy-thymol isobutyrate (1), which was computationally converted into a ring-closed structure to explain interaction with the COX-2 enzyme in a ligand-receptor docking study. The resulting docked pose is in line with reported crystal complexes of COX-2 with chromene ligands. Based on the present results of dichloromethane extracts from its dried leaves, it is safe to utter that the plant possesses analgesic effects in animal tests which are mediated through inhibition of COX-2 enzyme.

Ageratina glabrata is widely distributed in Mexico and it is popularly known for its analgesic activity. Though this specie has been chemically studied, there are no reports about any analgesic effects. In this phytopharmaceutical study, the analgesic effect of A. glabrata was evaluated in two thermal models of acute pain in rat, namely: hot plate and tail flick tests. Doses of 100mg/Kg and 150 mg/Kg of extract were used for the hot plate test, and 100mg/kg for the tail flick test. Preliminary results showed an analgesic effect 5 hours after the administration of the leaf extract of A. glabrata, in the hot plate test.

Ageratina glabrata está ampliamente distribuida en México y es conocida popularmente por sus efectos analgésicos. Aunque esta especie ha sido estudiada químicamente, no hay estudios acerca de su efecto analgésico. En este trabajo fitofarmacéutico se evaluó el efecto analgésico del extracto de A.glabrata en dos modelos térmicos de dolor agudo en rata: la prueba del plato caliente y en la prueba de retirada de la cola. Se probaron dosis de extracto de 100mg/Kg y 150 mg/Kg para la prueba de plato caliente, y 100mg/Kg para la prueba de retirada de la cola. Los resultados preliminares obtenidos muestran que el extracto de hoja de A. glabrata posee efecto analgésico 5 horas posteriores a la administración en la prueba de plato caliente.