ABSTRACT
Artemisia annua L., known for antimalarial activity, has demonstrated evidence of anti-inflammatory potential. Previously our research group reported the anti-inflammatory and antinociceptive effect of a sesquiterpene lactone-enriched fraction (Lac-FR) obtained from plant, containing artemisinin and deoxyartemisinin. Both the isolated compounds and Lac-FR evaluated on experimental animal models, in the formalin test showed that deoxyartemisinin reduced both neurogenic pain (56.55â¯%) and inflammatory pain (45.43â¯%). These findings were superior to the effect of artemisinin (reduction of 28.66â¯% and 33.35â¯%, respectively). In the tail flick test, the antinociceptive effect reported as a percentage of the maximum possible effect (%MPE), deoxyartemisinin showed a lower antinociceptive effect (41.57â¯%) compared to morphine (75.94â¯%) in 0.5â¯h. After 1.5â¯h, the MPE of deoxyartemisinin (87.99â¯%) exceeded the effect of morphine (47.55â¯%), without reversal with naloxone. The MPE of artemisinin (23.3â¯%) observed after 2â¯h was lower than deoxiartemisinin, without reversal with the opioid antagonist. Lac-FR and artemisinin demonstrated reductions in ear edema of 43.37â¯% and 48.19â¯%, respectively, higher than the effect of deoxyartemisinin (33.64â¯%). Artemisinin reduced tumor necrosis factor alpha (TNF-α) (76.96â¯%) more selectively when compared to interleukin-1beta (IL-1ß) (48.23â¯%) and interleukin-6 (IL-6) (44.49â¯%). Lac-FR showed greater selectivity in IL-6 reduction (56.49â¯%) in relationship to TNF-α (46.71â¯%) and IL-1ß (45.12â¯%), whereas deoxyartemisinin selectively reduced TNF-α (37.37â¯%). The results of our study indicate that the lactones isolated did not have relationship with the opioid system. Deoxyartemisinin showed a higher antinociceptive potential than artemisinin. Whereas, artemisinin showed a higher reduction of inflammation and mediators, with a better anti-inflammatory activity outcome.