Effects of ginseng saponin on acute cocaine-induced alterations in evoked dopamine release and uptake in rat brain nucleus accumbens

Abstract

In traditional medicine, Panax ginseng has been used to treat various behavioral effects of psychostimulants (e.g., cocaine) and other drugs of abuse and to ameliorate withdrawal symptoms. The neurochemical bases for this efficacy, however, remain to be elucidated. We previously used the real-time fast-scan cyclic voltammetry in rat nucleus accumbens slices to demonstrate that cocaine not only enhances DA release evoked by single-pulse electrical stimulation and inhibits DA uptake during application but also further increases the release upon washout (termed a “rebound” release enhancement). In the present study, we determined whether co-application and washout of ginseng total saponin (GTS), the active ingredient of Panax ginseng, with cocaine attenuate cocaine-induced enhancement of evoked DA release, DA uptake inhibition and/or withdrawal-associated rebound enhancement. Cocaine rapidly potentiated the DA release within the first 10 min of application, and acute cocaine withdrawal caused a rebound increase. Co-application of GTS with cocaine inhibited the release enhancement and subsequently prevented the rebound increase during acute withdrawal. The effect of GTS was concentration-dependent. In contrast, GTS had no significant effects on the cocaine-mediated DA uptake inhibition. These results suggest that the attenuation of the cocaine-induced enhancement of impulse-dependent DA release, rather than uptake inhibition, might be one of the pharmacological bases for attenuation of behavioral effects of cocaine and amelioration of acute withdrawal symptoms by ginseng.

Effects of Ginsenoside Rg₃ on α9α10 Nicotinic Acetylcholine Receptor-Mediated Ion Currents

“…1A). Ginsenosides exhibits diverse biological activities in nervous systems, 18) with neuropharmacological actions such as analgesia, neuroprotection against neurotoxins or excitatory amino acids.…”

“…16) It is known that blockage of α9α10 nicotinic acetylcholine receptor reduces inflammation-related nerve injury. 17) Ginsenosides, one of ginseng components, is a substance of low molecular weight uniquely found in ginseng 18) (Fig. 1A).…”

“…1A). Ginsenosides exhibits diverse biological activities in nervous systems, 18) with neuropharmacological actions such as analgesia, neuroprotection against neurotoxins or excitatory amino acids. 19) However, the cellular mechanisms of ginsenoside activity are relatively unknown, especially with regards to possible regulation of receptors or ion channels involved in synaptic transmission in nervous system.…”

“…1A). Ginsenosides exhibits diverse biological activities in nervous systems, 18) with neuropharmacological actions such as analgesia, neuroprotection against neurotoxins or excitatory amino acids.19) However, the cellular mechanisms of ginsenoside activity are relatively unknown, especially with regards to possible regulation of receptors or ion channels involved in synaptic transmission in nervous system.In previous reports, we have shown that ginsenosides or ginsenoside metabolites regulates the Cys-loop family of ligand-gated ion channels, such as 5-hydroxytryptamine 3A, human glycine α1 and nicotinic acetylcholine receptors. For example, the application of ginsenoside Rg 2 inhibits 5-hydroxytryptamine-and glycine-induced peak inward currents (I 5-HT and I Gly ) of mouse 5-hydroxytryptamine 3A and human glycine α1 receptor channels expressed in Xenopus laevis oocytes.…”

Análise farmacognóstica de amostras de drogas vegetais psicoativas comercializadas em Diadema

“…As atividades têm sido atribuídas às substâncias glicosiladas, de núcleo esteroidal, que exercem os diversos efeitos na região central e periférica do sistema nervoso (DANG et al, 2009;NAH et al, 2009 Figura 6. Metilxantinas presentes em Paullinia cupana.…”