Few studies have explored the effects of the combined use of alcohol and cigarette in humans, despite its prevalence. Here we evaluated the effect of isolated and combined use on behaviors and neuronal parameters in rats. Male adult rats were divided into alcohol (AL, 2 g/kg, by oral gavage), cigarette smoke (TB, six cigarettes, by inhalation), combined use (ALTB), or control (CT, water by oral gavage and environmental air) groups, treated twice a day (09.00 and 14.00 h). After 4 weeks, the rats were tested in the open field for behavioral analysis and euthanized for brain volume estimation and counting of neurons in the hippocampus. All treatments increased locomotion, and this behavior was higher in the ALTB than TB group. Latency to exit from the central area was lower in the ALTB than in the AL or CT groups. Rearing behavior increased in TB and decreased in AL and ALTB rats. Combined ALTB rats significantly increased their grooming behavior. Only the AL group showed decreased neuron counts and increased brain volume. Our results show that the isolated and combined uses of alcohol and cigarette smoke have diverse effects on behavioral and neuronal parameters in rats after long-term treatment.

Copaiba oleoresin, extracted from the Copaifera reticulata tree, has been used as a remedy in popular medicine in the Brazilian Amazon for various purposes, including reducing drug abuse. Yet no studies evaluated the effect of repeated administration of copaiba oil on alcohol consumption in animals. To evaluate this effect, we divided adult male Wistar rats into a) an alcohol group in which the animals had free access to choose between two bottles: one containing alcohol solution (20%) and another containing vehicle solution (0.2% saccharin); and b) a control group with access to two bottles containing vehicle solution. Rats were free to drink 24 h per day, for 35 days. Daily alcohol consumption and weekly body weight gain and food intake were monitored. From day 22, half of the rats in each group received 600 mg kg-1 copaiba oleoresin and the other received vehicle, subcutaneously, once a day, for three days. On day 35, rats were evaluated in an open-field test. The results showed that copaiba oil decreased voluntary alcohol intake and preference between days 2 and 6 after the last administration. Copaiba treatment also decreased the food intake and body weight gain in both alcohol and control groups without changing behaviors in the open-field test. Therefore, copaiba oil was able to reduce voluntary alcohol consumption in rats and could be tested in humans as an adjuvant to treat alcohol use disorder.