Behavioural sensitisation following repeated intermittent oral administration of Catha edulis in rats

A prolonged use of psychostimulants has been suggested to induce long-lasting behavioural sensitisation which plays a role in the acquisition and maintenance of addictive behaviour. A study was conducted to evaluate the effect of repeated oral administration of Catha edulis in rats. Male Sprague-Dawley rats divided into five groups received: saline, S-(-)-cathinone (1.5 mg/kg), D-(+)-amphetamine, (1.5 mg/kg) and standardized C. edulis extract (50 or 200 mg/kg) once daily for nine consecutive days and later challenged with the same psychostimulants after five abstinence days. Then, 2 weeks later, rats were decapitated and the level of neurotransmitters were assessed. Behavioural activities were monitored using activity and sniffing boxes. The results demonstrated that the three psychostimulants induced strong behavioural sensitisation in rats. Whereas, neurotransmitters analyses showed no significant changes in the basal level of dopamine in most of the regions except that C. edulis extract (200 mg/kg) significantly reduced the level of DA, DOPAC and HVA in the anterior caudate putamen (P < 0.05). The capacity of C. edulis to elicit a long-lasting behavioural sensitisation support the anecdotal literatures about psychiatric problems associated with C. edulis chewing. (C) 2004 Elsevier B.V. All rights reserved.