Plant derivatives in the treatment of alcohol dependency

The present review summarizes the findings of the effects of extracts of purified compounds from several plants on alcohol intake in alcohol-preferring rats. These include St. John's wort ( Hypericum perforatum, HPE), kudzu ( Pueraria lobata) and ibogaine ( Tabernanthe iboga). Alcohol-preferring (P), Marchigian Sardinian (msP), high-alcohol-drinking (HAD), Fawn-Hooded (FH) rats were allowed to drink alcohol or water voluntarily to establish baseline levels. Pure compounds (puerarin, daidzin, daidzein or analogs) isolated from kudzu, extracts from HPE or ibogaine and its analog were given by either intraperitoneal or oral administration. After acute administration, all agents dose-dependently reduced alcohol intake with minimal effects on food intake. Puerarin and HPE were also effective following chronic treatment. Overall, it is clear that pure compounds (daidzin, puerarin), extracts from St. John's wort, ibogaine and an ibogaine analog suppress alcohol intake in animal models of excessive drinking with minimal effects on other appetitive behaviors. Although the true mechanisms of action of these compounds on alcohol intake are not fully understood, with the current information, it appears that these compounds exert their effects by modulating several neuronal systems implicated in drinking behavior. However, their role in the future of pharmacotherapy for alcoholism will depend upon the outcome of carefully conducted clinical trials.