Effects of Jitai tablet, a traditional Chinese medicine, on spontaneous withdrawal symptoms and modulation of dopaminergic functions in morphine-dependent rats.

Chronic opioid abuse can cause damage to dopamine neurons. However, there are currently no effective pharmacotherapies to reverse this damage, even though progress has been made in the development of therapeutic strategies for opioid dependence. The Jitai tablet (JTT) is a traditional Chinese medicine formulation most commonly used for opioid addiction treatment in China. In a morphine spontaneous withdrawal rat model we investigated the effects of JTT, either given before (pre-treatment) or after (post-treatment) morphine administration, on the dopamine system. Our study has shown the following: (1) pre- and post-treatment with JTT were effective at alleviating the wet dog shakes and episodes of writhing; (2) pre-treatment with JTT inhibited the morphine-induced decreases in dopamine transporter (DAT), dopamine D2 receptor (D2 R) and tyrosine hydroxylase (TH) levels in the striatum (p < 0.01, compared with morphine group) and maintained them at normal levels; and (3) post-treatment with JTT restored the densities of DAT, D2 R and TH in the striatum to normal levels (p < 0.01, compared with morphine group). These results support the notion that modulation of the dopamine system in the striatum may play a role for JTT's therapeutic effect on the alleviation of opioid withdrawal symptoms.