Essential Oils from Citrus latifolia and Citrus reticulata Reduce Anxiety and Prolong Ether Sleeping Time in Mice

Essential oils (EO) from Citrus reticulata and Citrus latifolia were submitted to classical experimental procedures, such as light-dark box and marble-burying tests with male Swiss mice, to evaluate anxiolytic activity. Sedative activity was also investigated with EO from C. aurantium using the sleeping time induced by ether inhalation. EOs were administered 30 min before the experiments in doses ranging from 0.5 to 2.0 g/kg (w/v). EO from C. latifolia showed a positive effect on light-dark box parameters, and those from both C. reticulata and C. latifolia were able to reduce the number of buried marbles. Positive results were obtained using experimental procedures related to generalized anxiety (light-dark box) and obsessive-compulsive disorders (marble-burying), suggesting some differences in the spectrum of anxiolytic activity. EO from all citrus species significantly increased the duration of sleep induced by ether inhalation, disregarding the potential interaction with hepatic enzymes, which is a limitation of barbiturate sleeping time. On the other hand, this effect was detected only with higher doses, emphasizing that specificity of this action should be investigated. Results obtained with EOs from C. reticulata and C. latifolia confirm the central nervous system activity previously described for C. aurantium. Further investigation is warranted to guarantee the safe use of EOs by the population.