Analgesic effect of aqueous extract of Olea europaea L. in experimental models of pain in male rat

The medicinal plant Olea europaea L. is a valuable one whose fruit and its oil are considered as food. There are some reports in ancient medical literature that aqueous extract of its leaves has analgesic effects. This prompted us to investigate the analgesic effect of aqueous extract of its leaves using formalin and tail-flick tests. For this purpose, male NMRI rats weighting 220-260 g were used in all experiments. The aqueous extract of this plant was intraperitoneally injected at doses of 200, 400, and 600 mg/kg. In this study, sodium salicylate (300 mg/kg) and distilled water were used as positive and negative controls respectively. The results obtained were analyzed using one-way ANOVA and Tukey-Kramer tests. Our data showed that intraperitoneal injection of aqueous extract of the leaves of this plant (200, 400, and 600 mg/kg) produces a significant analgesia in both phases of the formalin test (P