Antinociceptive Effects of Paeonia daurica subsp. macrophylla Root Extracts in Mice

Abstract

This study aimed to assess the antinociceptive activity of extracts and fractions of Paeonia daurica subsp. macrophylla in BALB/c mice. Various doses of hydro-alcoholic extract (HE), hexane fraction (F-hexane), methanol (F-MeOH), and chloroform (F-CHCl₃), as well as aqueous extracts (AE), were evaluated by a well-known model, a formalin-induced pain test in mice. All extracts, piroxicam 0.1 mg/kg, and negative control groups were administered 30 minutes before formalin injection. Flinching, licking, and biting reflexes were measured as painful factors compared with controls at intervals of 0 to 5 minutes, 0 to 15, and 0 to 60 minutes after formalin injection. The acute oral toxicity test of total ethanolic and aqueous extracts showed no signs of toxic effect up to a dose of 5000 mg/kg. In the formalin test at a time interval of 0 to 5 minutes, there was no significant difference between the results of the study groups. In the range of 0 to 15 minutes, the effect of AE (1 g/kg), HE (2, 3 g/kg), and F-hexane (1 g/kg) was significantly higher than the positive control group (p<0.01). In the time interval of 0 to 60 minutes as the total time of the experiment, the effect of AE (0.25 g/kg), AE (0.5, 1 g/kg), HE (2, 3 g/kg), F-hexane (1 g/kg) were significantly different than the positive control group. It can be concluded that extract of P. daurica subsp. macrophylla might be helpful in the treatment of pain in humans.