Spasmolytic and anti-inflammatory effects of Aloysia triphylla and citral, in vitro and in vivo studies

Aloysia triphylla is traditionally utilized for the treatment of menstrual colic (primary dysmenorrhea) in Mexico. Citral is the main chemical component found in Aloysia triphylla leaves extract. Primary dysmenorrhea is a very frequent gynecological disorder in menstruating women, affecting 30-60% of them. It is usually treated with non-stereidal anti-inflammatory drugs (NSAIDs); although their effect is rapid, they possess many side effects. Due to the shortcomings, Mexican folk therapy is considered as a feasible alternative. The effects of the hexane extract of Aloysia tripylla and citral on uterine contractions were evalueted in vitro as well as their anti-inflammatory properties and gastric wound capabilites were assessed in vivo. The inhibitory effects on the contractions were analysed using isolated uterus strips from estrogen primed rats. Contractions were induced by KC1 60 mM, oxytocin 10 mIU/mL, charbacol 10 mM and PGF2a 5 mM. The anti-inflammatory effect was assessed on carrageenan-induced rat hind paw edema model. The extract of Aloysia triphylla produced a significant inhibitory effect on PGF2a-induced contraction compared to its inhibitory actions on the others. Citral exhibited the same inhibitory effect on the contraction induced by PGF2a. The oral administration of the extract (100-800 mg/kg) and citral (100-800 mg/kg) showed anti-inflammatory activity; furthermore, the maximal dose utilized did not produce gastric injury. Thes results were compared with anti-inflammatory effects and gastric damage produced by 30 mg/kg of indomethacin p.o. The spasmolytic and anti-inflammatory effects support the traditional use of Aloysia triphylla leaves in the tratment of the primary dysmenorrhea in Mexican communities.