Figure 4: Effect of intraperitoneal administration of chloroformic
(CHCl3) olive leaves extract on acetic acid-induced writhing in
mice. Values are mean ± SEM. ∗∗P < .01, ∗∗∗P < .001 versus
control group, (n = 6).
mechanism action. In fact, various mediators are released by
carrageenan in the rat paw. Thus, while the initial phase is
mainly mediated by the release of histamine and serotonin,
the second phase is due to the release of prostaglandins,
protease, and lysosome [13–15]. Our results indicate that
the olive leaves extracts significantly inhibit the development
of carrageenan-induced rat paw edema. Similar results
were noted in the presence of aqueous extract of citrillus
colocynthis [16]. In addition, the mechanism of action
may involve inhibition of production of proinflammatory
cytokine (IL-6; IL-1β) and of the expression of COX-2 and
at stimulation of the anti-inflammatory cytokine (IL-4) [17].
Interestingly, the anti-inflammatory effect of both tested
extracts appears to be similar to that of dexamethasone, a
steroidal anti-inflammatory drug, since in both cases the
effect becomes more marked with time. In our experiment,
we were limited to five hours after the injection of the
phlogistic agent. It would be interesting to extend the time
of our experimentation (24 h) to observe the effects of the
extracts.