The relationship between anxiety-related behaviors and voluntary ethanol intake was examined in two pairs of rat lines by the oral ethanol self-administration procedure. Floripa high (H) and low (L) rats selectively bred for contrasting anxiety responses in the open-field test, and two inbred strains, spontaneously hypertensive rats (SHR) and Lewis rats which are known to differ significantly when submitted to several behavioral tests of anxiety/emotionality, were used (9-10 animals/line/sex). No differences in the choice of ethanol solutions (2%, days 1-4, and 4%, days 5-8, respectively) in a 2-bottle paradigm were detected between Floripa H and L rats (1.94 ± 0.37 vs 1.61 ± 0.37 g/kg for ethanol intake on day 8 by the Floripa H and L rat lines, respectively). Contrary to expectations, the less anxious SHR rats consumed significantly more ethanol than Lewis rats (respective intake of 2.30 ± 0.45 and 0.72 ± 0.33 g/kg on day 8) which are known to be both addiction-prone and highly anxious. Regardless of strain, female rats consumed more ethanol than males (approximately 46%). The results showed no relationship between high anxiety and voluntary intake of ethanol for Floripa H and L rats. A negative association between these two variables, however, was found for SHR and Lewis rat strains. Data from the literature regarding the association between anxiety and alcohol intake in animal models are not conclusive, but the present results indicate that factors other than increased inborn anxiety probably lead to the individual differences in ethanol drinking behavior.

RESUMO:A investigação de plantas medicinais como recurso terapêutico para combater o alcoolismo ainda é muito insipiente com poucas espécies investigadas. No presente trabalho avaliamos o efeito do extrato hidroalcoólico das folhas da planta Piper caldense C. DC. com relação ao consumo de álcool e também a sua potencialidade ansiolítica. Foram utilizados ratos Wistar machos, os quais foram divididos em grupos controle (solução fisiológica) e tratado (extrato da planta nas doses de 25, 50 e 150 mg/kg, e diazepam 2 mg/kg). Os animais foram tratados através da via intraperitoneal 1 h antes dos experimentos. Os modelos animais utilizados foram: Labirinto em Cruz Elevado (LCE) e auto-administração de álcool (AA). No LCE o extrato não apresentou efeito ansiolítico do tipo benzodiazepínico. Por outro lado, no comportamento relacionado a auto-administração de solução de álcool, o extrato apresentou efeito significativo reduzindo o consumo de álcool em relação ao grupo controle. Apesar do extrato não ter apresentado efeito ansiolítico, o mesmo parece apresentar potencialidades para combater o abuso e a dependência de álcool. PALAVRAS-CHAVE:Piper caldense C. DC., labirinto em cruz elevado, auto-administração de álcool.ABSTRACT: The hydroalcoholic extract of leaves of Piper caldense C. DC. decreases alcohol consumption in rats. The investigation of medicinal plants as therapeutic resources in the combat of alcoholism is still very incipient with few species being investigated. The purpose of the present study was to examine the effects of the hydroalcoholic extract of leaves of Piper caldense C. DC. in relation to alcohol consumption and also its anxiolytic potentiality. Male Wistar rats, which had been separated into control group (saline) and treated group (Plant extract doses of 25, 50 and 150 mg/kg and 2 mg/kg of diazepam), were used. Animals were injected intraperitoneally 1 h before the tests. The following models were used: Elevated plus maze (EPM) and alcohol self-administration (ASA). In the EPM, the extract did not show benzodiazepine anxiolytic effect. On the other hand, in the behavior related to alcohol self-administration, the extract showed a significant effect, reducing alcohol consumption compared to the control group. Although the extract has not shown any anxiolytic effect, the results suggest that the plant has potential to combat alcohol abuse and addiction.Key words: Piper caldense C. DC., elevated plus maze, alcohol self-administration.10.1590/1983-084X/12_145 INTRODUÇÃOA busca por novos fármacos que possam combater o alcoolismo é um desafio constante tendo rendido até o momento três fármacos clinicamente bem estabelecidos, dissulfiram (Suh et al., 2006), naltrexona (Johnson B.A., 2008) e acamprosato (Mason & Heyser, 2010). Mesmo assim, a eficácia destes medicamentos é relativa (Popova et al., 2011), portanto a busca por outros fármacos é fundamental. Um campo a ser explorado é o das plantas medicinais, como este é muito amplo, uma maneira de delimitá-lo é estudar plantas que apresentam alguma ação s...