Modulation of Chelidonii herba on glycine-activated and glutamate-activated ion currents in rat periaqueductal gray neurons

Background: Chelidonii herba is classified as Papaver somniferum L. Aqueous extract from C. herba is traditionally used for disorders with symptoms like pain, bloating, abdominal cramp after meals. Methods: Modulation of C. herba on glycine-activated and glutamate-activated ion currents in the acutely dissociated periaqueductal gray (PAG) neurons was investigated by the nystatin-perforated patch-clamp technique. Results: C. herba inhibited glycine-activated ion current and increased glutamate-activated ion current. C. herba-induced inhibition on glycine-activated ion current is implicated in opioid receptors and GTP-binding proteins (G-proteins). Increased glutamate-activated ion current induced by C. herba is linked neither by opioid receptors nor GTP-binding proteins. Conclusions: Suppressed glycine-induced response and elevated glutamate-induced response by C. herba may increase neuronal excitability in PAG, results in activation of descending pain control system, and this mechanism can be suggested as one of the analgesic actions of C. herba.