Fennel oil treatment mimics the anti-depressive and anxiolytic effects of fluoxetine without altering the serum cholesterol levels in rats

Synthetic antidepressants are effective drugs for the treatment of psychiatric disorders. Along with the effectiveness these drugs are also associated with some side effects. Since ancient times herbs are used as medicinal purposes. One such herb is Fennel (Foeniculum vulgare). Fennel has many efficacious uses. It is a common herb and spice. It is used in many culinary purposes and also it has therapeutic purposes. In the present study antidepressant effects of fennel oil was monitored by comparing it with a synthetic antidepressant drug, fluoxetine. The rats were divided into three groups as control, drug and oil which were respectively treated with water, fluoxetine (0.3 mg/kg) and fennel oil (0.5 ml/day). The treatment was continued for three weeks. Struggling time in forced swim test (FST), number of square crossed in open field test (OFT) and time spent in open arm in elevated plus maze (EPM) was monitored weekly. Repeated administration of fennel oil for 3 weeks showed significant antidepressant- and anxiolytic-like effects in FST and EPM, respectively which were comparable to fluoxetine treated group. A significant increased cholesterol levels were observed in fluoxetine treated rats which was not observed in fennel oil treated rats. Therefore, repeated administration of fennel oil may exert antidepressive- and anxiolyticlike behaviors. These effects were found to be comparable to that of the clinically used synthetic drug, fluoxetine.