Sauchinone blocks methamphetamine-induced hyperlocomotion and place preference in mice

Effects of the GluN2B-selective antagonist Ro 63-1908 on acquisition and expression of methamphetamine conditioned place preference in male and female rats

BACKGROUND

Methamphetamine abuse has increased significantly in recent years. Currently, there are no FDA-approved pharmacotherapies for the treatment of methamphetamine use disorder. The goal of the current study was to determine if the N-methyl-d-aspartate (NMDA) GluN2B-selective antagonist Ro 63-1908 can block the conditioned rewarding effects of methamphetamine as assessed in conditioned place preference (CPP).

METHODS

Two main experiments were conducted. In the first experiment, male (n = 24) and female (n = 24) rats received either vehicle or Ro 63-1908 (1.0-10.0 mg/kg) 30 min prior to the posttest to determine if blocking the GluN2B subunit attenuates expression of methamphetamine CPP. In the second experiment, male (n = 18) and female (n = 18) rats received either vehicle or Ro 63-1908 (1.0 or 3.0 mg/kg) 30 min prior to each conditioning session to determine if blocking the GluN2B subunit attenuates acquisition of methamphetamine CPP.

RESULTS

Ro 63-1908 (3.0 mg/kg) blocked acquisition of methamphetamine CPP in male rats, but only attenuated CPP in female rats. Ro 63-1908 did not alter expression of CPP in either sex. Increasing the dose of Ro 63-1908 (10.0 mg/kg) failed to block acquisition of CPP in an additional group of female rats (n = 6). A control experiment showed that Ro 63-1908 (3.0 mg/kg) did not produce CPP or conditioned place aversion in male rats (n = 6) or in female rats (n = 6).

CONCLUSIONS

The results of this study show that Ro 63-1908 is able to decrease the conditioned rewarding effects of methamphetamine.

The Role of Chinese Herbal Therapy in Methamphetamine Abuse and its Induced Psychiatric Symptoms

Repeated intake of methamphetamine (METH) leads to drug addiction, the inability to control intake, and strong drug cravings. It is also likely to cause psychiatric impairments, such as cognitive impairment, depression, and anxiety. Because the specific neurobiological mechanisms involved are complex and have not been fully and systematically elucidated, there is no established pharmacotherapy for METH abuse. Studies have found that a variety of Chinese herbal medicines have significant therapeutic effects on neuropsychiatric symptoms and have the advantage of multitarget comprehensive treatment. We conducted a systematic review, from neurobiological mechanisms to candidate Chinese herbal medicines, hoping to provide new perspectives and ideas for the prevention and treatment of METH abuse.

Sauchinone Blocks Ethanol Withdrawal-Induced Anxiety but Spares Locomotor Sensitization: Involvement of Nitric Oxide in the Bed Nucleus of the Stria Terminalis

Both the positive (manifested by locomotor sensitization) and negative (withdrawal symptoms) reinforcing effects of ethanol (EtOH) involve central nitric oxide (NO) signaling. Sauchinone (a bioactive lignan in Saururus chinensis) has been shown to improve methamphetamine-induced behavioral and neurochemical changes via the NO signaling pathway. Thus, this study evaluated the effects of sauchinone on locomotor sensitization and anxiety during EtOH withdrawal (EtOHW). Male adult Sprague-Dawley rats were treated with 1.5 g/kg/day of EtOH (20%, vol/vol) via intraperitoneal injection for 28 days, followed by a 3-day withdrawal. During withdrawal, the rats were given intragastric sauchinone (2.5, 7.5, or 25 mg/kg/day) once a day. EtOH locomotor sensitization was determined by challenging EtOHW rats with 0.75 g/kg EtOH, while EtOHW-induced anxiety was assessed using the elevated plus maze (EPM). None of the three doses of sauchinone affected EtOH locomotor sensitization. However, in the EPM, treatment of EtOHW rats with sauchinone at 7.5 or 25 mg/kg/day increased both the number of entries into and the time spent in the open arms. Moreover, the two doses of sauchinone inhibited the oversecretion of plasma corticosterone during EtOHW. In the bed nucleus of the stria terminalis (BNST), EtOHW increased NO production, enhanced gene and protein expression of both inducible nitric oxide synthase (iNOS) and neuronal NOS (nNOS), and also elevated protein levels of corticotropin-releasing factor, which were all inhibited by 25 mg/kg/day sauchinone. In an in vitro experiment, sauchinone (3, 10, and 30 μM) inhibited H₂O₂-stimulated nNOS protein expression in neuronal PC12 cells. Finally, intra-BNST infusion of sodium nitroprusside, a NO donor, after sauchinone (25 mg/kg/day) administration, abolished its expected anxiolytic effect. Taken together, these results indicate that sauchinone attenuates anxiety-like behavior in rats during EtOHW but spares EtOH locomotor sensitization, and the anxiolytic effect is mediated via the NO signaling pathway in the BNST.

Pharmacotherapeutic agents in the treatment of methamphetamine dependence

INTRODUCTION

Methamphetamine use is a serious public health concern in many countries and is second to cannabis as the most widely abused illicit drug in the world. Effective management for methamphetamine dependence remains elusive and the large majority of methamphetamine users relapse following treatment. Areas covered: Progression in the understanding of the pharmacological basis of methamphetamine use has provided us with innovative opportunities to develop agents to treat dependence. The current review summarizes relevant literature on the neurobiological and clinical correlates associated with methamphetamine use. We then outline agents that have been explored for potential treatments in preclinical studies, human laboratory phase I and phase II trials over the last ten years. Expert opinion: No agent has demonstrated a broad and strong effect in achieving MA abstinence in Phase II trials. Agents with novel therapeutic targets appear promising. Advancement in MA treatment, including translation into practice, faces several clinical challenges.