目的 探讨人参皂苷Rg1对大鼠胸腺组织结构与功能的影响及相关机制。 方法 SD大鼠随机分为2组，每组10只。Rg1注射组，腹腔注射Rg1 20mg/kg，qd×28d；对照组，等时注射等量生理盐水。药物注射完成后第2天，取胸腺称重测定胸腺指数，石蜡切片与HE染色观察胸腺组织结构；衰老相关β-半乳糖苷酶（SA-β-Gal）染色检测胸腺细胞衰老，细胞计数试剂盒（CCK-8）检测胸腺细胞对刀豆蛋白A（ConA）刺激的增殖能力，ELISA检测胸腺细胞分泌肿瘤坏死因子-α（TNF-α）、粒细胞巨噬细胞集落刺激因子（GM-CSF）、白细胞介素（IL)-2与IL-6的能力，流式细胞术检测胸腺细胞周期、细胞凋亡率与活性氧（ROS）含量，酶学检测丙二醛（MDA）、超氧化物歧化酶（SOD）含量与还原性谷胱甘肽（GSH）与氧化性谷胱甘肽（GSSH）的比值，Western blotting 检测细胞衰老相关蛋白P21、P53、Rb表达。 结果 与对照组相比，注射Rg1能提升大鼠胸腺指数，增加胸腺皮质面积比例，提高胸腺细胞增殖能力和S期比例，降低G₁期与G₂/M期细胞比例，减少胸腺细胞凋亡和SA-β-Gal阳性细胞百分率，促进胸腺细胞分泌GM-CSF，TNF-α、IL-2、IL-6，提升胸腺细胞SOD活性和GSH/GSSG比例，降低ROS、MDA含量，下调P53、P21、RB蛋白表达。 结论 人参皂苷Rg1对大鼠胸腺结构与功能有明确的保护作用，其机制可能与抑制氧化损伤和下调p53/p21/Rb信号通路有关。

Objective To investigate the effect of ginsenoside Rg1 on the thymus structure and function and its relative mechanism. Methods Twenty male SD rats were randomly divided into two groups. Rg1 group rats were injected with Rg1 20mg/kg qd×28days by intraperitoneal way; the control group rats were treated with saline at the same dose and time. After 2 days of the treatment, the weight and index of thymus were measured, paraffin section and HE staining were used to observe the thymus’s microscopic structure and calculate the proportion of the cortex of thymus. SA-β-Gal staining was applied to detect aging thymocytes. The proliferative capacity of thymocyte stimulated by Con A was measured by CCK-8. The cell cycles, apoptosis and reactive oxygen species(ROS) of thymocytes were assayed with flow cytometry. The amounts of tumor necrosis factor-α(TNF-α), granulooyte-macrophage colony stimulating factor(GM-CSF), IL-2, IL-6, advanced glycosylation end products (AGEs)produced by thymocytes were assayed with ELISA. Malondialdehyde (MDA), superoxide dismutase (SOD), proportion of GSH and GSSH were detected by enzymatic assay. The expression of senescence-accosiated protein P53, P21, Rb were detected by Western blotting analysis. Results The injection of ginsenoside Rg1 significantly enhanced the thymic index, the proportion of the cortex of thymus, the proliferative capacity of thymocytes, the ratio of the thymocytes in S stage, the secretory capability of TNF-α, GM-CSF, IL-2 and IL-6, the active content of SOD, and proportion of GSH/GSSG,and decreased the ratio of apoptosis,G1 and G2/M stage, the production of ROS and MDA of the thymocytes. Ginsenoside Rg1 down regulated the expression of P53, P21, Rb. Conclusion Ginsenoside Rg1 can protect the structure of thymus and activate the function of thymocytes. Its mechanism may be that ginsenoside Rg1 can inhibit oxidative stress and down regulate p53/p21/Rb signal pathway.