Foeniculum vulgare Mill (Umbelliferae) Attenuates Stress and Improves Memory in Wister Rats

Purpose: To evaluate the anti-stress and memory-enhancing properties of F. vulgare extract in experimental rats. Methods: F. vulgare plant extract was obtained using Soxhlet extraction technique. The extract, at doses of 50, 100 and 200 mg/kg body weight, was administered orally with an orogastric tube. Urinary levels of vanillylmandelic acid (VMA) and ascorbic acid in rats were used to evaluate anti-stress activity. Conditioned avoidance response was measured in normal and scopolamine-induced amnesic rats to study the memory-enhancing effects. Lipid peroxidation inhibition assay in liver and brain homogenates of rats was used to evaluate antioxidant activity. Results: Daily administration of F. vulgare extract (50, 100 and 200 mg/kg body weight) 1 h prior to induction of stress significantly (p < 0.05) altered the stress-induced urinary biochemical levels of VMA from 395.79 +/- 11.23 to 347.12 +/- 12.28, 311.21 +/- 12.48 and 258.86 +/- 10.26 mu g/kg, respectively, in 24 h, as well as ascorbic acid excretion levels from 65.74 +/- 9.42 to 78.59 +/- 8.44, 108.41 +/- 15.62 and 125.82 +/- 16.94 mu g/kg also within the same period, respectively. These changes occurred in a dose-dependent fashion, and the levels in the control groups were unchanged within the same period. The memory deficits induced by scopolamine (1mg/kg, i.p.) in rats was reversed by F. vulgare dose-dependently. The extract also exhibited potent antioxidant effect by inhibition of lipid peroxidation in both rat liver and brain homogenates to a greater extent than the standard antioxidant, ascorbic acid. Conclusion: F. vulgare may be useful in the management of stress and stress-related disorders on account of its multiple actions such as anti-stress, memory-enhancing and antioxidant effects.