l-Stepholidine, a Naturally Occurring Dopamine D1 Receptor Agonist and D2 Receptor Antagonist, Attenuates Methamphetamine Self-Administration in Rats

Given the problems associated with the escalation in methamphetamine (METH) use, the identification of more effective treatment strategies is essential. l-stepholidine (l-SPD) is an alkaloid extract of the Chinese herb Stephania intermedia with dopamine D1 receptor partial agonistic and D2 receptor antagonistic dual actions. The unique pharmacological profile of l-SPD suggests that l-SPD may be effective for the treatment of METH addiction. The aim of this study was to characterize the effect of l-SPD on METH self-administration on a fixed-ratio 1 schedule. We found that 5 and 10 mg/kg of l-SPD attenuated METH self-administration behavior. These results demonstrate that l-SPD which possesses dual actions on dopamine D1 and D2 receptors, attenuates METH self-administration on a fixed-ratio 1 schedule.