Chronic Effect of Thunbergia laurifolia Extract and Cocaine in Rats Using Behavior Model of Addiction
Watchareewan Thongsaard PhD*, Ratirat Sangpayap BSc*, Charles Marsden PhD**
Affiliation : * Department of Physiology, Faculty of Medicine, Srinakharinwirot University, Bangkok, Thailand ** School of Biomedical Sciences, Faculty of Medicine and Health Sciences, University of Nottingham, Nottingham, UK
Background : Thunbergia laurifolia Linn. (TL) is a herbal medicine which has been used as a component of a mixture of crude
extracts to treat drug addicted patients. TL extract was reported to increase dopamine levels significantly in the rat brain both
in vitro and in vivo studies similar to that seen with cocaine and TL stimulated in the same brain area that amphetamine
stimulated.
Objective : The study aims to investigate whether long term treatment with TL can cause addiction or not by comparing with
known addicted drug, cocaine, using the conditioned place preference test.
Material and Method: Chronic oral administration (30 days) of crude water extract of TL (1 and 10 g/kg, orally) and cocaine
(1 mg/kg, orally) were performed to determine the alteration of addiction behavior using a conditioned place preference
(CPP) test.
Results : Rats received chronic treatment of cocaine became addicted. While, both doses of TL (1 and 10 g/kg, orally) did not
cause significantly in the time spent in both compartment between pre- and post-drug treatment.
Conclusion : When treated long-term and tested with CPP test of addiction, rats received chronic treatment of cocaine became
addicted. On the other hand, both doses of crude water extract of TL (1 and 10 g/kg, orally) did not cause significant changed
in the time spent in both compartment between pre- and post- drug treatment indicating that TL did not cause addiction.
Keywords : Addiction, Cocaine, Conditioned place preference (CPP) test, Thunbergia laurifolia
