Chronic effect of thunbergia laurifolia extract and cocaine in rats using behavior model of addiction

Abstract

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. © 2015, Medical Association of Thailand. All rights reserved.