Berberine hydrochloride attenuates voluntary methamphetamine consumption and anxiety-like behaviors via modulation of oxytocin receptors in methamphetamine addicted rats.
OBJECTIVE
Methamphetamine (METH) addiction is recognized as one of the major public health concerns, with no approved pharmacological agents for treatment. Berberine hydrochloride, an isoquinoline alkaloid in plants, induces antipsychotic and anxiolytic effects. Hence, we hypothesized that berberine may modulate the METH-induced rewarding effects.


MATERIALS AND METHODS
In this study, three groups of rat including control (N = 10), METH + vehicle (N = 10), and METH + berberine (N = 10) were kept in separate cages one day before expriments. METH (20 mg/L) was dissolved in tap water inside a bottle, while there was only tap water in the control bottle. Two groups received free METH solutions for two weeks (up to 12 mg/kg). Afterwards, they were abstianced for three weeks. Only one group received 100 mg/kg/day of berberine. After three weeks, locomotor activity and anxiety (elevated plus maze test) were evaluated, then the two-bottles choice model was used for one week to evaluate drug preferences. Finally, the brain of rats was removed for evaluation of oxytocin receptor expression via immunofluorescence staining method.


RESULTS
The results showed that METH preference was lower in the berberine + METH group during drug intake compared to the METH group (P < .05). During withdrawal, berberine reduced anxiety-like behaviors (P < .05) and decreased locomotor activity versus the METH group (P < .001). Also, berberine increased numbers of oxytocin receptors in comparison with the METH group (P < .01).


CONCLUSION
Considering the modulation of oxytocin receptors, berberine may be considered as a potential therapeutic agent for METH addiction.
['Alavijeh|Mahnaz Mesripour|MM|', 'Vaezi|Gholamhassan|G|', 'Khaksari|Mehdi|M|', 'Hojati|Vida|V|']
D019969:Amphetamine-Related Disorders D000818:Animals D014151:Anti-Anxiety Agents D001007:Anxiety D001522:Behavior, Animal D001599:Berberine D000697:Central Nervous System Stimulants D058999:Drug-Seeking Behavior D006624:Hippocampus D008124:Locomotion D008694:Methamphetamine D009714:Nucleus Accumbens D051381:Rats D018045:Receptors, Oxytocin D012646:Self Administration
Oxytocin receptor Methamphetamine addiction Anxiety Drug preference Berberine hydrocholoride