人参皂苷Rg1对抑郁症模型大鼠行为学及海马氨基酸的影响

目的:观察人参皂苷Rg1对长期慢性应激所致抑郁模型大鼠行为学及海马氨基酸含量的影响。方法:将SD大鼠随机分为5组:正常对照组、模型组、人参皂苷Rg1低、高剂量组(20,40 mg·kg-1)和阳性药组(氟西汀10 mg·kg-1)。采用慢性不可预见性温和应激方法造成大鼠抑郁模型,治疗组灌胃连续给药21 d,正常组及模型组每日等剂量生理盐水灌胃。造模前后测定各组大鼠糖水消耗量,造模后旷场试验测定大鼠水平活动和垂直活动变化,以高效液相法测定海马氨基酸含量。结果:与正常组相比,模型组大鼠糖水消耗及偏爱率均下降;旷场试验测定水平活动和垂直活动次数均下降;海马谷氨酸、天冬氨酸含量明显增高,氨基丁酸和牛磺酸含量则明显下降。人参皂苷Rg1干预后,大鼠糖水消耗量和偏爱率增加;水平活动和垂直活动次数明显增加;海马谷氨酸、天冬氨酸含量下降,氨基丁酸和牛磺酸含量上升。结论:人参皂苷Rg1对抑郁症状有明显改善作用,其机制可能与调节长期慢性应激反应海马氨基酸水平,防止兴奋性氨基酸的神经毒性作用有关。

Effect of ginsenoside Rg1 on behaviors and hippocampal amino acids in depressive-like rats

Objective: To observe the effect of ginsenoside Rg₁ on behavior and hippocampal amino acids in depressive-like rats. Method: SD rats were randomly divided into 5 groups: control, model, fluxetine, low dose ginsenoside Rg₁ and high dose of ginsenoside Rg₁. The chronic unpredictable mild stress (CUMS) was performed to induce depressive-like animal model. Fluxetine group was orally given fluxetine in dose of 10 mg·kg^-1 for 21 days, low dose ginsenoside Rg₁ group was orally given ginsenoside Rg₁ in dose of 20 mg·kg^-1 for 21 days, high dose ginsenoside Rg₁ group was orally given ginsenoside Rg₁ in dose of 40 mg·kg^-1 for 21 days. The control and model group was orally given saline for 21 days. The sucrose consumption was detected before and after the CUMS procedure. The horizontal and vertical activities of rats were determined by open-field test. HPLC was adopted to detect the contents of amino acids in hippocampus. Result: The sucrose consumption, horizontal and vertical activities in CUMS rats were decreased compared with those in control group. Compared with control group, the contents of glutamate (Glu) and aspartate (Asp) in hippocampus of CUMS group were increased, while the gamma amino butyric acid (GABA) and taurine (Tau) were decreased. Ginsenoside Rg₁ treatment significantly increased the CUMS-induced decrease in sucrose consumption, horizontal and vertical activities. Administrated with ginsenoside Rg₁ also decreased Glu and Asp and increased the GABA and Tau in hippocampus in a dose dependent manner. Conclusion: Ginsenoside Rg₁ could alleviate the behavior changes of depressive-like rats, which might be related to regulate the levels of amino acids in hippocampus during CUMS and prevent the neuro-toxicity of excitatory amino acids.