Chronic treatment with curcumin enhances methamphetamine locomotor sensitization and cue-induced reinstatement of methamphetamine self-administration.
Zhao C, Lou Z, Zimmer B, Yu Z, Li P, Ma B, Sun Y, Huang K, Zhou W, Liu Y.
Source
Ningbo University School of Medicine, 818 Fenghua Road, Ningbo, Zhejiang 315211, PR China.
Abstract
OBJECTIVES:
Curcumin, a major active component of Curcuma longa, possesses antidepressant effects that are mediated by the 5-HT system. However, little is known about the effect of curcumin on the behavioral consequences of methamphetamine (METH).
METHODS:
The subjects were male, adult Sprague-Dawley rats. In Experiment 1, the effects of 20 and 40 mg/kg curcumin (i.p.) on response rates and breakpoints of 0.06 mg/kg/infusion METH were evaluated. In Experiment 2, rats were self-administering METH for 10 days followed by a 14-day abstinence period. During the abstinence period, the animals were treated with DMSO, 20 or 40 mg/kg curcumin. All rats were then tested for extinction responding and cue-induced reinstatement. In Experiment 3, rats were treated with DMSO, 20, or 40 mg/kg curcumin 15 min before a METH-induced locomotor activity test for 14 consecutive days. In Experiment 4, rats were pretreated with DMSO or curcumin (20 mg/kg or 40 mg/kg) for 13 days and were subsequently tested for METH-induced locomotor activity on the 14th day. In Experiment 5, three groups were tested for locomotor activity after an injection of DMSO, 20, or 40 mg/kg curcumin. The test was repeated for 14 days.
RESULTS:
Curcumin produced little effect on response rates and breakpoints maintained by METH. Chronic treatment of only 40 mg/kg curcumin during the abstinence phase enhanced cue-induced reinstatement of METH self-administration. Chronic administration of curcumin increased METH-induced sensitization of locomotor activity at the lower (20 mg/kg) but not higher (40 mg/kg) dose. However pretreatment of curcumin alone showed no significant effect on acute locomotor responses to METH and locomotor responses per se.
CONCLUSIONS:
Curcumin enhanced, rather than inhibited the behavioral effects of METH.
Copyright © 2012 Elsevier Inc. All rights reserved.
PMID: 22750063 [PubMed - indexed for MEDLINE]
http://www.ncbi.nlm.nih.gov/pubmed/22750063