Analgesic Activity and Chemical Constituents of Extracts of two Medicinal Species of Urtica

MARRASSINI, CARLA; GORZALCZANY, SUSANA; ACEVEDO, CRISTINA; LÓPEZ, PAULA; FERRARO, GRACIELA

Montpellier, Francia

Conferencia; XXV International Conference on Polyphenols; 2010

Two South American species were studied, one native, Urtica circularis, and other naturalized, Urtica urens, with similar morphological characteristics, which are locally used in popular medicine for the relief of rheumatic and muscular pain. The U. urens and U. circularis' extracts display a similar behaviour showing significant antinociceptive effect in chemically induced mouse pain models. Considering the mechanisms implied in the algesic action produced by acetic acid and formalin in the Writhing and Formalin Tests, respectively, the effect of the extracts might be mediated by the reduction of prostaglandins´ synthesis. Since their activity is significant in the second phase in the Formalin test and as naloxone could not antagonize the effect, it can be concluded that the extracts don't have central activity. In brief, these extracts would act in a similar way to indomethacine, their effect would be unrelated to the activation of the opioid system and the presence of chlorogenic acid or other flavonoid compounds could be responsible for this activity.