银杏叶提取物对辐射损伤小鼠脾脏细胞凋亡和NF-κB信号通路的影响

Effect of ginkgo biloba L.extract on apoptosis and NF-κB signaling pathways in the spleen tissue of mice with radiation damage

目的探讨银杏叶提取物对辐射损伤小鼠脾脏细胞凋亡相关蛋白表达和NF-κB信号通路的影响。方法将小鼠按随机数字表法分为空白对照组、辐射对照组,银杏叶提取物低、中、高剂量组,每组12只。低、中、高剂量组小鼠分别腹腔注射银杏叶提取物5、10、20 mg/kg,空白对照组和辐射对照组腹腔注射生理盐水,1次/d,连续给药14 d,第15天除空白对照组外均接受总剂量为4.0 Gy的γ射线全身均匀照射1次。于照射后24 h,采用免疫组化检测各组小鼠脾脏组织Bcl-2、Bax和caspase-3的蛋白表达,采用qRT-PCR法检测脾脏组织核因子κB抑制物激酶β(inhibitor kappa B kinaseβ, IKKβ)表达,采用ELISA法检测血清中NF-κB p65和IKKα水平。结果与辐射对照组比较,银杏叶提取物低、中、高剂量组小鼠脾脏Bax[(54.31±1.59)、(42.04±1.56)、(32.08±2.43)比(68.68±3.12)]、caspase-3[(55.73±2.61)、(45.81±2.59)、(36.78±2.23)比(72.18±1.84)]蛋白水平降低,Bcl-2[(30.33±1.28)、(39.80±2.86)、(44.42±3.64)比(22.80±2.01)]蛋白水平升高(P<0.05),IKKβ mRNA[(1.43±0.06)、(1.31±0.06)、(1.17±0.09)比(1.64±0.10)]表达和血清中NF-κB p65[(129.38±8.41)pg/ml、(111.28±9.09)pg/ml、(95.407±6.88)pg/ml比(145.64±6.29)pg/ml]、IKKα[(160.10±8.94)pg/ml、(144.00±8.36)pg/ml、(108.84±13.74)pg/ml比(176.38±8.54)pg/ml]含量降低(P<0.05)。结论银杏叶提取物可降低辐射所致小鼠脾脏细胞中凋亡蛋白Bax和caspase-3表达,升高抗凋亡蛋白Bcl-2表达水平,通过调控NF-κB信号通路拮抗辐射造成的机体损伤。

Objective To investigate the influence of Ginkgo biloba L. extract (EGB) on the expression of apoptosis-related protein and NF-κB signaling pathway in the spleen tissue of mice with radiation damage. Methods The mice were divided randomly into normal control group (NC), irradiation control group (IC), low dose EGB group (IC+EGBL), medium dose EGB group (IC+EGBM) and high dose EGB group (IC+EGBH) according to the random number table, with 12 rats in each group. The mice in the low, middle and high dose EGB groups were given EGB respectively by 5, 10, 20 mg/kg, and the normal and irradiation control group were given saline by intraperitoneal injection once daily for 14 days. On the 15th day, the mice in all groups were uniformly irradiated with 4.0 Gy γ-rays for one time except normal control group. After 24 hours, Bcl-2, Bax and caspase-3 protein expression were measured by immunohistochemical method. The IKKβ expression was detected by qRT-PCR method, and the content of NF-κB p65 and IKKα in serum was detected by Elisa method in spleen tissue. Results Comparing with IC group, the expression of Bax (54.31 ± 1.59, 42.04 ± 1.56, 32.08 ± 2.43 vs. 68.68 ± 3.12) and caspase-3 protein (55.73 ± 2.61, 45.81 ± 2.59, 36.78 ± 2.23 vs. 72.18 ± 1.84) in IC+EGBL, IC+EGBM and IC+EGBH group were significantly decreased (P<0.05), the expression of Bcl-2 protein (30.33 ± 1.28, 39.80 ± 2.86, 44.42 ± 3.64 vs. 22.80 ± 2.01) in IC+EGBL, IC+EGBM and IC+EGBH group significantly increased (P<0.05), the expression of IKKβ mRNA (1.43 ± 0.06, 1.31 ± 0.06, 1.17 ± 0.09 vs. 1.64 ± 0.10) and the level of NF-κB p65 (129.38 ± 8.41 pg/ml, 111.28 ± 9.09 pg/ml, 95.41 ± 6.88 pg/ml vs. 145.64 ± 6.29 pg/ml) and IKKα(160.10 ± 8.94 pg/ml, 144.00 ± 8.36 pg/ml, 108.84 ± 13.74 pg/ml vs. 176.38 ± 8.54 pg/ml) in IC+EGBL, IC+EGBM and IC+EGBH group significantly decreased (P<0.05). Conclusions The EGB can reduce the expression of apoptotic protein Bax and caspase-3 in spleen cells induced by radiation, elevate the expression level of apoptotic protein Bcl-2, and inhibit the damage caused by radiation by regulating NF-κB signaling pathway.