Effect of Flavonoids in Scutellariae Radix on Depression-Like Behavior and Brain Rewards： Possible in Dopamine System

A series of animal models are used to investigate the anti-depression mechanism of flavonoids in scutellariae radix （SR） in vivo. Depression-like behavior in mice was studied after intraperitoneal administra- tion of SR. The results showed that SR administered to mice by the intraperitoneal route obviously short- ened the duration in the tail suspension test and the forced swimming test, aggravated the symptoms of eyelid ptosis, akinesia, and mortality caused by reserpine, prolonged climbing times, affected the condi- tioned place preference, and increased sugar consumption in mice. However the SR did not affect the head twitches induced by 5-HTP, locomotor activity in mice, the toxicity of yohimbine, and the body temperature decrease caused by high dosage of apomorphine. The tests show that SR has some anti-depression effect related to the dopamine system. Furthermore another anti-depression mechanism was possible that could affect the mechanism of brain reward, bring positive reinforcement, and increase the sensitivity to euphoria in mice.