Studies On The Anxiolytic Effect Of Succinic Acid

The anxiolytic effect and the mechanism of succinic acid (SA) were preliminarily investigated by means of behavioral methods for the first time. Toxicity and the properties of SA were also investigated in the work. The differences of central depressant properties were clarified between SA and DZ.In the elevated plus-maze test, SA (3, 6 mg/kg) induced significant increases in the percentage of entries into open arms and of time spent on open arms. In the open field test, SA (4.2 mg/kg) significantly increased number of entries into the central arena and time spent in the central sector of the open field, produced the antithigmotactic effect. In the hole-board test, SA (2.1 mg/kg) increased the number and duration of head-dips, and decreased the latency to head-dipping. In the novel food consumption test, SA (3-12 mg/kg) casued significant increases in food intake when compared with the vehicle. In the light-dark transition test, SA (3-12 mg/kg) increased the number of transitions and the time spent in the light box. In the stress-induced hyperthermia test, SA (1.5 mg/kg) inhibited stress-induced hyperthermia. In the social interaction test, SA (2.1, 4.2 mg/kg) increased total interaction time under high and low light unfamiliar condition and its following components: grooming, following, crawling over, fighting, sniffing. Thus, these findings indicated that SA exhibitsanxiolytic-like effects because of the increases of the exploratory and social behavior.SA did not change the motor activity, the traction performance, the roto-rod performance, and the angle of inclined plane. SA did not produce the influence on amobarbital sodium or ethanol-induced sleeping. These results suggest that SA hasn't central depressant effect at the dose of anxiolitic-effect, and doesn't influence the muscle and motor coordination.In the elevated plus-maze and light-dark tests, the interaction effects of SA and mCPP or SA and PTX were studied. These study demonstrated that: (1) mCPP did not decrease the increases of the percentage of entries into open arms, the percentage of time spent on open arms and the number of transitions induced by SA; and (2) PTX selectively antagonized the anxiolytic-like effects of SA, and significantly altered the aforementioned indices.In conclusion, the presented study indicated that SA possesses anxiolytic-like effects, and the GABA ergic-benzodiazeping system may play a role in the SA induced anxiolytic effect.