Assessment the role of opioidergic neurons on antinociception of hydroalchoholic extract of propolis on acute and visceral pain in mice

Introduction: Our previous study showed that hydroalchoholic extract of propolis has antinociception effects. The mechanism(s) that mediate this effects are not clear. The present study was designed to test the peripheral and visceral antinoceceptive effects and role of opiate system in the antinociceptive effects of hydroalchoholic extract of propolis on acute, and visceral pain in mice by using Hot Plate (HP), Tail Flick (TF), and Writhing (WR) tests.Methods: In this experimental study 144 young adult male albino mice (25-30 g) in 18 groups (n = 8 in each group) were used. Propolis (100, 200, and 500 mg/Kg IP),and vehicle (VEH) were used 30 min before the pain evaluation tests. Acute pain was assessed by HP and TF models and Visceral pain was assessed by writhing test. In addition, Naloxone (NAL, 2 mg/Kg, IP) was injected 15 min before the most effective of propolis extract administration in order to assess the role of opiate neurons in the antinociception effects of propolis.Results: Results indicated that propolis, have analgesic effects (p < 0.05) in comparison with the control group and higher dose of propolis was more effective (p < 0.001). Besides, pretreatment of NAL modulates the antinociceptive effects of propolis in all models.Conclusion: The above findings showed that propolis, have modulator effects on pain. These findings further indicate that the existence of an interaction between antinociceptive effects of propolis and opiate neurons.

Keywords:

propolis , Acute Pain , Visceral pain , Opiate neurons , Mice.