Antinociceptive and anti-inflammatory effects of Sambucus ebulus rhizome extract in rats

Abstract

In this study we used the chronic (formalin test) and acute (tail flick) pain models of rats for evaluation of probable analgesic and anti-inflammatory effect of Sambucus ebulus (Se) rhizome extract. Sodium salicylate (SS) was used as a positive control. A total of 300 mg/kg of SS (i.p.) had no effect on tail flick latency, while 100 and 200 mg/kg i.p. of extract increased this latency ( P<0.01 and P<0.001, respectively). In formalin test, SS (300 mg/kg i.p.) and extract (100 mg/kg i.p.) alleviated the animals’ nociception in the second phases, while in the first phase, only the extract caused an anti nociceptive effect ( P<0.05). A total of 200 mg/kg of the extract showed a significant effect on both phases ( P<0.001), which was not reversed by naloxone (2 mg/kg i.p.). On the other hand in the acute anti-inflammatory test, the plant extract (200 mg/kg i.p.) showed a significant effect, (e.g. SS P<0.01) and was not reversed by naloxone (2 mg/kg i.p.).Therefore, it seems that the mechanism of the antinociceptive and anti-inflammatory actions of extract are not related to the opioid system, of course the comparison of chronic administration of SS and Se showed a rapid onset of action for Se rather than SS, and because of its effect on tail flick latency and both phases of formalin test, the site of its analgesic action is probably central. Our phytochemical studies indicate that methanol extract of plant rhizome contains flavonoids, steroids, glycosides and tannins. The LD 50 of the extract was 600 mg/kg.