矮垂头菊正丁醇提取物改善高原缺氧小鼠脑组织损伤的作用

n-Butanol Extract of Cremanthodium Humile Ameliorates Brain Tissue Damage Induced by Hypobaric Hypoxia in Mice

目的研究矮垂头菊正丁醇提取物对高原缺氧小鼠脑组织的保护作用。方法将50只小鼠分为缺氧模型组、阳性对照组(乙酰唑胺)和矮垂头菊正丁醇提取物低、中、高剂量组(125、250、500 mg·kg^(-1)),进行常压密闭缺氧实验选择最佳给药剂量。另将40只小鼠分为正常对照组、低压低氧组、阳性对照组(乙酰唑胺)和矮垂头菊正丁醇提取物给药组(500 mg·kg^(-1)),连续灌胃5 d,最后一次给药后,除正常对照组外,其余小鼠在模拟8000米海拔的低氧舱中暴露24 h,随后处死小鼠,取脑组织,测定丙二醛、乳酸、过氧化物酶、乳酸脱氢酶、谷胱甘肽过氧化物酶、超氧化物歧化酶和总抗氧化能力的水平,酶联免疫法测定脑组织中白细胞介素-1β、白细胞介素-6和肿瘤坏死因子-α含量,蛋白印迹法检测脑组织中核因子E2相关因子2、血红素加氧酶1、核转录因子-κB和肿瘤坏死因子-α蛋白的表达水平。结果与正常对照组比较,低压低氧组小鼠脑组织中丙二醛、乳酸、乳酸脱氢酶的含量显著升高(P<0.01),炎性因子白细胞介素-1β、白细胞介素-6和肿瘤坏死因子-α的水平增加(P<0.05),超氧化物歧化酶、过氧化氢酶、谷胱甘肽过氧化氢酶和总抗氧化能力的水平显著降低(P<0.01),核因子E2相关因子2、血红素加氧酶1、核转录因子-κB、肿瘤坏死因子-α的蛋白表达增加(P<0.05),各指标数据均有显著性差异,因此低压低氧模型建立成功。与低压低氧组比较,矮垂头菊正丁醇给药组小鼠脑组织中丙二醛、乳酸、乳酸脱氢酶的含量显著降低(P<0.01),炎性因子白细胞介素-1β、白细胞介素-6和肿瘤坏死因子-α的水平降低(P<0.05),超氧化物歧化酶、过氧化氢酶、谷胱甘肽过氧化氢酶和总抗氧化能力的水平显著升高(P<0.01),核转录因子-κB、肿瘤坏死因子-α的蛋白表达降低(P<0.05),而核因子E2相关因子2和血红素加氧酶1的蛋白水平表达进一步升高(P<0.05)。结论矮垂头菊正丁醇提取物能够激活Nrf-2/HO-1通路,抑制炎性因子的释放,从而降低高原缺氧诱发的氧化应激和炎性反应,缓解脑组织损伤。

Objective To study the protective effect of n-butanol extract of Cremanthodium humile(BECH)against brain tissue damage induced by hypobaric hypoxia in mice.Methods As normobaric hypoxia experiments,fifty mice were divided into the hypoxia model group,positive control group(acetazolamide)and BECH low,medium and high dose(125,250 and 500 mg·kg^(-1))groups to select the best dose for administration.Another forty mice were divided into the normal control(NC)group,hypobaric hypoxia(HH)group,positive control(acetazolamide)group and BECH(500 mg·kg^(-1))administration group.Drugs were given intragastrically for five days.After the last administration,the mice except those in the NC group were exposed to a simulated altitude of 8000 m for 24 h in a hypobaric hypoxia chamber.Subsequently,the mice were sacrificed and brain tissues were taken.The levels of malondialdehyde(MDA),lactate(LD),catalase(CAT),lactate dehydrogenase(LDH),glutathione peroxidase(GSHPx),superoxide dismutase(SOD),and total antioxidant capacity(T-AOC)in brain tissues were determined using commercial assays.The contents of interleukin-1β(IL-1β),interleukin-6(IL-6)and tumor necrosis factor-α(TNF-α)were determined via enzyme-linked immunosorbent assay(ELISA).Western blot was used to determine the expressions of nuclear factor E2-related factor 2(Nrf-2),heme oxygenase 1(HO-1),nuclear transcription factor-κB(NF-κB),and TNF-α.Results Compared with the NC group,the levels of MDA,LD,and LDH in brain tissues of mice in the HH group were significantly increased(P<0.01),so were the levels of inflammatory factors IL-1β,IL-6,and TNF-α(P<0.05),but the levels of SOD,CAT,GSH-Px,and T-AOC were significantly decreased(P<0.01),and the protein expressions of Nrf-2,HO-1,NF-κB and TNF-αwere elevated(P<0.05).There were significant differences in indexes between the two groups,so a hypobaric hypoxia model was established.Compared with the HH group,the levels of MDA,LD and LDH in brain tissues of mice in the BECH administration group were significantly decreased(P<0.01),those of inflammatory factors IL-1β,IL-6 and TNF-αwere decreased(P<0.05),those of SOD,CAT,GSH-Px and T-AOC were significantly increased(P<0.01),protein expressions of NF-κB and TNF-αwere decreased(P<0.05),while those of Nrf-2 and HO-1 kept increasing(P<0.05).Conclusion BECH can inhibit oxidative stress by activating the Nrf-2/HO-1 pathway and mitigate inflammatory response by reducing the release of inflammatory factors,thus ameliorating brain tissue damage induced by hypobaric hypoxia.