甘西鼠尾草总酚酸提取物对电离辐射诱导小鼠肠道炎症的保护作用及机制

Protective Effect and Mechanism of Total Phenolic Acid Extract from Salvia Przewalskii on Intestinal Inflammation Induced by Ionizing Radiation in Mice

目的研究甘西鼠尾草总酚酸提取物(SPE)对电离辐射诱导小鼠肠道炎症的保护作用,探讨其调节Toll样受体4(TLR4)/核因子κB(NF-κB)/核苷酸结合寡聚化结构域样受体蛋白3(NLRP3)炎症小体信号通路抑制电离辐射的作用机制。方法选取48只雄性KM小鼠,按照随机数字表法分为正常对照组、辐射模型组、SPE低剂量组、SPE中剂量组、SPE高剂量组和阳性药白藜芦醇组(白藜芦醇组),每组8只。除正常对照组不予以辐射外,其余各组小鼠均接受5.5 Gy^(60)Coγ射线一次性照射。辐射前2 d及辐射后7 d,SPE低、中、高剂量组小鼠分别以75 mg/kg、150 mg/kg、300 mg/kg剂量给予相应的SPE溶液灌胃;正常对照组、辐射模型组小鼠分别给予0.9%氯化钠溶液灌胃,白藜芦醇组小鼠给予剂量为30 mg/kg的白藜芦醇溶液灌胃。辐射7 d后,观察各组小鼠小肠肠道组织病理损伤、外周血常规指标(白细胞、红细胞、血小板、血红蛋白)、脾脏系数及小肠肠道组织中NLRP3、NF-κB、白细胞介素-1β(IL-1β)蛋白表达的变化。结果与辐射模型组相比,白藜芦醇组小鼠肠道组织浸润性炎症损伤程度显著降低,SPE各组小鼠肠道组织炎性症状均减轻。各组白细胞、红细胞、血小板、血红蛋白水平比较差异有统计学意义(均P<0.01)。与正常对照组相比,辐射模型组、SPE低、中、高剂量组和白藜芦醇组白细胞、红细胞、血小板、血红蛋白水平均降低(均P<0.01)。与辐射模型组相比,SPE低、中、高剂量组和白藜芦醇组白细胞、红细胞、血小板、血红蛋白水平均升高(P<0.05或P<0.01)。各组小鼠的脾脏系数比较差异有统计学意义(P<0.01)。与正常对照组相比,辐射模型组、SPE低、中和高剂量组的脾脏系数均降低(P<0.01)。与辐射模型组相比,SPE高剂量组、白藜芦醇组脾脏系数均升高(0.58±0.09、0.64±0.14比0.46±0.08)(P<0.05或P<0.01)。各组NLRP3、NF-κB、IL-1β蛋白表达比较差异有统计学意义(均P<0.01)。与正常对照组相比,辐射模型组、SPE低、中、高剂量组、白藜芦醇组NLRP3、NF-κB、IL-1β蛋白表达均升高(P<0.05);与辐射模型组相比,SPE低、中、高剂量组和白藜芦醇组NLRP3、NF-κB、IL-1β蛋白表达均降低(P<0.05)。结论SPE可以通过调节NLRP3炎症小体减轻电离辐射引起的肠道炎症。SPE通过抑制TLR4蛋白,降低NLRP3炎症小体的表达,有效抑制电离辐射诱导的肠道炎症产生。

Objective To study the protective effect of Salvia przewalskii total phenolic acid extract(SPE)on ionizing radiation-induced intestinal inflammation in mice,and explore its mechanism of regulating Toll-like receptor 4(TLR4)/nuclear factor-κB(NF-κB)/nucleotide-binding oligomerization domain-like receptor protein 3(NLRP3)inflammasome signaling pathway to suppress ionizing radiation.Methods A total of 48 male KM mice were selected and randomly divided into a normal control group,a radiation model group,a low-dose SPE group,a medium-dose SPE group,a high-dose SPE group,and a positive drug resveratrol group(resveratrol group)using a random number table method,with 8 mice in each group.Except for the normal control group not receiving radiation,all other groups of mice received 5.5 Gy^(60)Coγsingle dose radiation irradiation.Two days before radiation and seven days after radiation,mice in the low,medium,and high-dose groups of SPE were given corresponding SPE solutions by gavage at doses of 75 mg/kg,150 mg/kg,and 300 mg/kg,respectively;normal control group and radiation model group mice were given 0.9%sodium chloride solution by gavage,while mice in the resveratrol group were given a dose of 30 mg/kg of resveratrol solution by gavage.7 days after radiation,the pathological damage of the small intestinal tissue,peripheral blood routine indicators(white blood cells,red blood cells,platelets,hemoglobin),spleen coefficient,and NLRP3,NF-κB and interleukin-1β(IL-1β)changes in protein expression in the small intestinal tissue of each group of mice were observed.Results Compared with the radiation model group,the degree of invasive inflammatory damage in the intestinal tissue of mice in the resveratrol group was significantly reduced,and the inflammatory symptoms in the intestinal tissue of mice in each SPE group were alleviated.The levels of white blood cells,red blood cells,platelets,and hemoglobin in each group showed statistically significant differences(all P<0.01).Compared with the normal control group,the levels of white blood cells,red blood cells,platelets,and hemoglobin in the radiation model group,SPE low,medium,and high-dose groups,and resveratrol group were all reduced(all P<0.01).Compared with the radiation model group,the levels of white blood cells,red blood cells,platelets,and hemoglobin in the SPE low,medium,and high-dose groups and the resveratrol group were all increased(P<0.05 or P<0.01).The difference in spleen coefficient among different groups of mice was statistically significant(P<0.01).Compared with the normal control group,the spleen coefficients of the radiation model group,SPE low,medium,and high-dose groups were all reduced(P<0.01).Compared with the radiation model group,both the SPE high-dose group and the resveratrol group showed an increase in spleen coefficient(0.58±0.09,0.64±0.14 vs 0.46±0.08)(P<0.05 or P<0.01).The difference of NLRP3,NF-κB,IL-1βin protein expression of each group was statistically significant(all P<0.01).Compared with the normal control group,the protein expression of NLRP3 and NF-κB,IL-1βof the radiation model group,SPE low,medium,and high-dose groups,and resveratrol group were increased significantly(P<0.05);compared with the radiation model group,the protein expression of NLRP3 and NF-κB,IL-1βof the SPE low,medium,and high-dose groups and the resveratrol group were decreased significantly(P<0.05).Conclusion SPE can alleviate intestinal inflammation caused by ionizing radiation by regulating NLRP3 inflammasomes.SPE effectively inhibits intestinal inflammation induced by ionizing radiation by inhibiting TLR4 protein and reducing the expression of NLRP3 inflammasome.