phytochemical screening and antinociceptive activity of the hydroalcoholic extract of potentilla reptans l.

Background: potentilla species have traditionally been used as anti-inflammatory and analgesic agents in iran and other countries. objectives: this study aimed to investigate the antinociceptive effect of potentilla reptans l., which has a wide distribution in the north of iran. methods: the biological activities of the hydroalcoholic extract of p. reptans aerial parts have been investigated using the acetic acid-induced writhing, hot plate, and rotarod tests in the male mice. in addition, the phytochemical profile of the extract has been evaluated. results: the phytochemical investigation detected secondary metabolites such as flavonoids, saponins, triterpenoids, and tannins in the extract. moreover, the mean±sd total phenolic and tannin contents of the extract were 251±2.08 and 111.5±1.3 mg gallic acid equivalents per gram of dried extract, respectively. also, the mean±sd total flavonoid content was 29.42±3.31 mg quercetin equivalents per gram of dried extract. oral administration of the extract (100, 300, and 500 mg/kg) dose-dependently reduced the number of writhing responses induced by acetic acid and increased the reaction time in the hot-plate test. the antinociceptive effect of the extract, similar to morphine, was significantly antagonized by naloxone (4 mg/kg; ip) in the writhing test. in the rotarod test, none of the extract doses used in the experiment caused a loss of locomotor activity. conclusion: in this study, the hydroalcoholic extract of p. reptans showed a practical antinociceptive effect in hot plate and writhing tests. it seems that opioid receptors mediate the observed effect.