First evidence of the analgesic activity of govaniadine, an alkaloid isolated from Corydalis govaniana Wall.

In this work, govaniadine, an alkaloid isolated from Corydalis govaniana Wall. was evaluated for its analgesic activity by writhing and hot-plate tests. Govaniadine did not display any toxic effects in mice up to 20 mg/kg during 24 h assessment study. The acetic acid-induced writhing was significantly reduced by pretreatment with govaniadine in a dose-dependent manner (1.25-5.0 mg/kg, intraperitoneally (i.p.)). Furthermore, molecular docking study has shown that this alkaloid binds the COX-2 enzyme. In the hot-plate test, govaniadine at dose of 2.5 and 5 mg/kg, i.p. displayed analgesic effect at all time points (30, 60, 90 and 120 min). The analgesic effect of govaniadine was significantly antagonised by naloxone administration. Our results demonstrate for the first time that the peripheral and central analgesic effects of govaniadine could be in part related to the involvement of COX-2 activity and by its interaction with the opioid system.