The final phase of the experiment consisted of studying the influence of Carum carvi extract on stress induced changes in the same groups of animals after a recovery period of one week.
The nootropic activity of Carum carvi was evaluated by using the conditioned avoidance response (CAR) in rats as described by Cook & Weidley (1957).
The antioxidant activity of Carum carvi was determined based on its ability to inhibit lipid peroxidation in homogenates of the liver and brain of rats (Okhawa 1979).
Daily treatment of Carum carvi to the animals under normal condition produced no change in the excretion of VMA and ascorbic acid compared with normal basal levels indicating that Carum carvi did not alter excretion of VMA and ascorbic acid in normal condition.
The CAR of rats administered with the extract of Carum carvi or vehicle increased gradually to 95% over seven to eleven days.
However continued treatment of Carum carvi produced better retention and recovery in a dose dependent manner than the vehicle treated animals.
The quantity of the Carum carvi extract needed for 50% inhibition of lipid peroxidation in rat liver homogenate was found to be 2350 [micro]g (Fig 4A).
In the present study the increase in the urinary VMA excretion during stress was used as a non invasive biochemical marker to study the antistress activity of Carum carvi.