[The experimental evaluation regarding analgesic activity of some extracts isolated from Achillea collina J. Becker...

In the present investigation we have evaluated the potential existence of analgesic activity of the residue of tincture and of the crude lipophilic (AC 2, AC 4) and hydrophilic portions (AC 1, AC 3) of infusion and decoction obtained from flower heads of Achillea collina J. Becker ex Reichenb. Acid acetic induced writhing and vascular permeability test was performed by the method of Whittle. Comparison was made with indomethacin, morphine and rutin, as references drugs. The mice were dosed orally with samples. AC 2 induced a potent inhibition (47.23%; p < 0.05) of the nociceptive response after oral administration of 250 mg/kg--a dose ten folds higher than the dose of indomethacin. AC 3, at a dose of 5000 mg/kg (p.o.) inhibited with 47.6% (p < 0.001) and 19.8% (p < 0.05) the increase in peritoneal vascular permeability caused by 0.5% acetic acid. Relative unexpected, morphine (1.14 mg/kg, p.o.), an opioid analgesic, also produced a significant reduction of the leakage (41.2%, p < 0.01). This finding is consistent with the reports in which the role of the endogenous opiate system in the physiological response to injury/inflammation, mainly controlling fluid leakage into the interstitial space, is sustained.