Blockade of nicotine sensitization by methanol extracts of Glycyrrhizae radix mediated via antagonism of accumbal oxidative stress

Abstract

BackgroundWe previously reported that a methanol extract of Glycyrrhizae radix (MEGR) blocked methamphetamine-induced locomotor sensitization and conditioned place preference in rats. In the present study, the effects of MEGR on repeated nicotine-induced locomotor sensitization and enhanced extracellular dopamine (DA) release in the nucleus accumbens (Nacc) were evaluated.MethodsMale Sprague–Dawley rats received repeated administrations of nicotine (0.4 mg/kg, subcutaneous) or saline twice a day for 7 d and were challenged with nicotine 4 d after the last daily dosing. During the 4-d withdrawal period, the rats were treated once a day with MEGR (60 or 180 mg/kg/d). Extracellular DA levels were measured by in vivo microdialysis, the malondialdehyde levels and the activities of superoxide dismutase and catalase in the Nacc were biochemically evaluated, and the expression of antioxidant proteins was confirmed by Western blot assays. All data were assessed with analysis of variance tests followed by post-hoc comparison tests and p values <0.05 were considered statistically significant.ResultsThe expression of repeated nicotine-induced locomotor sensitization was dose-dependently attenuated by MEGR, and 180 mg/kg/d MEGR significantly inhibited augmented accumbal DA release induced by a direct local challenge of nicotine. Moreover, 180 mg/kg/d MEGR reversed increases in malondialdehyde production, decreases in superoxide dismutase and catalase activities, and the reduced expression of nuclear factor erythroid 2–related factor 2 and heme oxygenase 1 in the nicotine-sensitized Nacc.ConclusionsThese results suggest that MEGR inhibited nicotine-induced locomotion and dopaminergic sensitization via antioxidant action.

Effect of Lycopene on Pharmacokinetic and Pharmacodynamics of Gliclazide in Diabetic Animal Models

“…It can be identified with the arrangement and furthermore usage of unnecessary pharmaceuticals at estimations or frequencies higher than medicinally essential. These helpful mixes may be noxious [1] or perfect [2] at the given therapeutic measurement. Diabetes mellitus (DM) is a metabolic issue implies with glucose level is unusually high because of insulin deficiency and work or both [3].…”

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

“…Western blots for the proteins of interest were analyzed as described previously [ 26 ]. Briefly, BNST tissues were homogenized, while harvested PC12 cells were lysed in a radioimmunoprecipitation assay lysis buffer containing protease inhibitors.…”

“…Evidence from clinical and animal studies indicates that besides the ones typically used to treat neurological disorders, some herbs historically used in nonneurological diseases show potential for treating addiction-related symptoms. For example, the radix of Glycyrrhiza uralensis , an herb widely used in the detoxification and treatment of various injuries, has been reported to improve the behavioral and neurochemical disturbances caused by nicotine and methamphetamine dependence [ 26 , 27 ]. Saururus chinensis , similar to G .…”