The Ameliorative Effect of L-theanine Combined with γ-aminobutyric Acid on CUMS-induced Depression in Rats

Objective:To observe the relaxation effect of combined intervention of L-theanine and γ-aminobutyric acid(GABA)on chronic unpredictable mild stress(CUMS)rats. Methods:The rat model of depression was established by CUMS. A mixture of L-theanine and GABA or citalopram with different dose was administered orally for 45 days during continuous CUMS stimulation.A control group was set up and fed routinely. The changes of body weight,sugar preference,horizontal and vertical movement were monitored. The levels of serotonin(5-HT),dopamine(DA),interleukin-6(IL-6),brain-derived neurotrophic factor(BDNF)and β-endorphin(β-EP)in serum and brain tissue were measured. Results:Compared with the control group,the body weight,percentage of sugar consumption,horizontal and vertical movement of CUMS rats decreased significantly(P<0.05). Compared with the model group,L-theanine combined with GABA could significantly increase body weight,sugar consumption percentage,horizontal movement distance and vertical movement frequency(P<0.05),enhance the contents of 5-HT,DA,BDNF and β-EP and decrease the level of IL-6 in brain tissue and serum of depressive rats(P<0.05). Conclusion:The combined intervention of L-theanine and GABA can improve the depression induced by CUMS,and the effect of high dose is more significant.