目的人参皂苷Rg1可增强神经元对缺氧缺血应激的耐受能力,在缺氧缺血性脑损伤(hypoxia ischemia brain damage,HIBD)中发挥一定的抗凋亡作用。观察人参皂苷Rg1对新生鼠HIBD后神经元凋亡及神经功能恢复的影响,并探讨其可能机制。方法 10天龄SPF级SD大鼠54只,体重16～22g,随机分为假手术对照组(假手术组,n=6)、HIBD模型组(模型组,n=24)和人参皂苷Rg1组(Rg1组,n=24)。模型组及Rg1组大鼠采用结扎右侧颈总动脉并低氧通气制备HIBD模型;假手术组仅分离右侧颈总动脉,不结扎,不进行低氧通气。Rg1组于术后即刻腹腔内注射0.1mL含人参皂苷Rg1(40mg/kg)的生理盐水,此后每隔24h按相同剂量注射人参皂苷Rg1;模型组和假手术组相同时间点腹腔内注射0.1mL生理盐水。术后观察大鼠一般情况,于术后4、8、24、72h采用Longa评分法行神经行为学评价后,处死大鼠取右侧脑组织,采用Western blot及免疫组织化学染色检测缺氧诱导因子1α(hypoxia inducible factor1α,HIF-1α)和活化的半胱天冬氨酸酶3(cleaved caspase3,CC3)蛋白表达;TUNEL法检测原位神经元凋亡情况。结果术后大鼠均存活至实验完成。与假手术组比较,模型组和Rg1组大鼠均出现不同程度的神经行为学异常;两组Longa评分与假手术组比较,差异均有统计学意义(P<0.05);术后72h时Rg1组与模型组比较,差异有统计学意义(P<0.05)。Western blot检测显示,各组各时间点均有HIF-1α、CC3蛋白表达;模型组及Rg1组各时间点HIF-1α蛋白表达均较假手术组有明显增加(P<0.05),Rg1组均较同一时间点模型组有明显上调(P<0.05)。模型组各时间点CC3蛋白表达均较假手术组明显增加(P<0.05),Rg1组仅术后4h与假手术组比较,差异有统计学意义(P<0.05);Rg1组各时间点均较模型组明显下调(P<0.05)。免疫组织化学染色可见HIF-1α蛋白、CC3蛋白定位主要集中在胞核及胞浆,各组各时间点蛋白表达强度与Western blot观察结果一致。TUNEL染色各组术后各时间点均见阳性细胞;模型组各时间点凋亡细胞数均较假手术组明显增加(P<0.05),Rg1组术后4、8h与假手术组比较,差异有统计学意义(P<0.05);Rg1组在8、24及72h凋亡细胞数目较模型组明显减少(P<0.05)。结论 Rg1通过增强并稳定HIF-1α信号途径,从而抑制半胱天冬氨酸酶3的活化,在新生鼠HIBD中发挥抗凋亡作用。 Objective The ginsenoside Rg1 can enhance the tolerance of neurons to hypoxia-ischemia stress and exert some anti-apoptosis effects in hypoxia ischemia brain damage (HIBD). Observe the effect of ginsenoside Rg1 on neuronal apoptosis and neurological recovery after neonatal rat HIBD, and explore its possible mechanism. Methods A total of 54 SPF SD rats of 10 days of age weighing 16-22 g were randomly divided into sham-operated control group (sham-operated group, n=6), HIBD model group (model group, n=24) and ginsenoside Rg1 group. (Rg1 group, n=24). Rats in the model group and Rg1 group were ligated to the right common carotid artery and subjected to hypoxic ventilation to prepare the HIBD model. In the sham operation group, only the right common carotid artery was isolated, no ligation was performed, and no hypoxic ventilation was performed. In the Rg1 group, 0.1 mL of normal saline containing ginsenoside Rg1 (40 mg/kg) was intraperitoneally injected immediately thereafter, and ginsenoside Rg1 was injected at the same dose every 24 hours; 0.1 mL was intraperitoneally injected at the same time point in the model group and the sham operation group. Normal saline. The general condition of the rats was observed after operation. The neurobehavioral assessment was performed using the Longa score at 4, 8, 24, and 72 hours after the operation. The right brain was removed from the rats and detected by Western blot and immunohistochemical staining. Expression of hypoxia inducible factor 1α (HIF-1α) and activated caspase 3 (CC3) protein; and TUNEL assay for in situ neuronal apoptosis. Results Postoperative rats survived until the completion of the experiment. Compared with the sham-operated group, both the model group and the Rg1 group exhibited neurobehavioural abnormalities of different degrees; the Longa scores of the two groups were statistically significant compared with the sham-operated group (P<0.05); Rg1 was 72 hours after surgery. Compared with the model group, the difference was statistically significant (P<0.05). Western blot analysis showed that HIF-1α and CC3 protein expression was observed in each group at each time point; HIF-1α protein expression in the model group and Rg1 group at each time point was significantly higher than that in the sham group (P<0.05). Compared with the same time point, the model group was significantly upregulated (P<0.05). The expression of CC3 protein in the model group was significantly higher than that in the sham group at each time point (P<0.05). The difference between the Rg1 group and the sham group was only 4 hours after operation (P<0.05). The Rg1 group was at each time point. Compared with the model group, it was significantly down-regulated (P<0.05). Immunohistochemical staining showed that the localization of HIF-1α protein and CC3 protein mainly concentrated in nucleus and cytoplasm, and the protein expression intensity of each group at each time point was consistent with that of Western blot. Positive cells were observed at each time point in each group after TUNEL staining; the number of apoptotic cells at each time point in the model group was significantly higher than that in the sham group (P<0.05), and the difference between the sham group and the 4th and 8th hours in the Rg1 group was different. There was statistical significance (P<0.05); the number of apoptotic cells in the Rg1 group at 8, 24, and 72 hours was significantly lower than that in the model group (P<0.05). Conclusion Rg1 inhibits the activation of caspase 3 by enhancing and stabilizing the HIF-1α signaling pathway and exerts an anti-apoptotic effect in neonatal rats with HIBD.