Effect of orange juice and tryptamine on the behavior and c-fos expression of Wistar rats

Recent reports have shown that commercial orange juice is rich in biogenic amines. Consumption of foods containing large amounts of biogenic amines increase hypertensive crisis and high levels of histamine and tyramine, which have been implicated as causative agents in a number of food poisoning episodes. In addition, accumulation of tryptamine in plasma may be associated with mood disorders. The aim of this study was to determine whether chronic administration of orange juice extract and tryptamine affects the behavior and c-fos expression in the rat. For this purpose, Wistar male rats were injected with saline solution, tryptamine or orange juice extract. Sucrose preference test and elevated plus maze were evaluated to determine hedonic and anxiety behavior, respectively. Rats treated with orange juice extract showed increased anxiety behavior and sucrose consumption, similar to those treated with tryptamine. In addition, dorsal raphe nucleus, accumbens nucleus, and hippocampus showed an increase of c-fos positive cells in rats treated with orange juice extract. In conclusion, the chronic and lengthy consumption of orange juice or their derivatives in the diet could be a factor responsible to induce mood disorders and may promote excess caloric consumption.