ABSTRACT
Calendula Officinalis [Asteraceae] is widely used in traditional medicine as an anti-inflammatory agent and has also been reported to have anti-bacterial, anti-fungal and anti-viral activities. Sesquiterpene glycosides, saponins, triol, triterpenes and flavonoids are observed in its composition. The present study was designed to evaluate the antinociceptive effect of hydro-alcoholic extract of Calendula Officinalis in male rats. The animals were treated intraperitoneally with different doses of the Calendula Officinalis flower extract [100, 150 and 250 mg/kg body weight]. On the basis of the previous report the dose of 150 mg/kg is most effective. The analgesic activity was tested by tail flick and acetic acid-induced writhing tests. Data between experimental groups were compared by one way analysis of variance [ANOVA] followed by tukey's as post hoc test. All doses of the extract and also naloxone + extract [150mg/kg] significantly increased the tail flick latency compared to the control group. The extract of Calendula Officinalis significantly reduced the number of abdominal constrictions and stretching of hind limbs induced by the injection of acetic acid. Naloxone + extract [150mg/kg] significantly increased the number of writhing. From the results it could be concluded that the Calendula Officinalis extract exhibits anti-nociceptive activity. Analgesic effects of Calendula Officinalis have the same pathway as opioids, but just in the peripheral test [acetic acid-induced writhing test]