条斑紫菜提取物对1型糖尿病小鼠肝脏炎症因子及氧化应激的影响

Effects of Porphyra yezoensis extract on hepatic inflammatory factors and oxidative stress in type 1 diabetic mice

目的 研究条斑紫菜提取物对1型糖尿病小鼠的肝脏炎症及氧化应激的影响。方法 91只C57BL/6J雄性小鼠适应性喂养2周,随机预留12只纳入空白对照组,其余小鼠隔夜禁食不禁水12 h后,一次性腹腔注射170.00 mg/kg链脲佐菌素,7 d后小鼠空腹血糖值≥16.7 mmol/L,且出现多饮、多食、多尿、体重下降判定为1型糖尿病造模成功。剔除模型失败鼠后,选取48只造模成功的小鼠按空腹血糖及体重随机分为4组:模型对照组,100、200和400 mg/kg条斑紫菜提取物组,每天灌胃1次,连续6周,空白对照组和模型对照组灌胃等量生理盐水。记录小鼠体重、体长变化。采用葡萄糖氧化酶法测定小鼠空腹血糖,采用酶联免疫法检测小鼠血清胰岛素含量、肝脏炎症因子水平及氧化应激指标,苏木精-伊红染色法观察肝脏、胰腺石蜡切片组织病理变化。结果 模型对照组和不同剂量条斑紫菜提取物干预组小鼠的体重均显著低于空白对照组(P<0.05),空腹血糖显著高于空白对照组(P<0.05);各条斑紫菜提取物干预组与模型组差异均无统计学意义。在炎症因子方面,与模型对照组相比,100 mg/kg条斑紫菜提取物能够提高1型糖尿病小鼠血清胰岛素水平、降低肝脏肿瘤坏死因子-α(tumor necrosis factor-α,TNF-α)水平(P<0.05),200 mg/kg条斑紫菜提取物可降低肝脏中TNF-α水平(P<0.05),400 mg/kg条斑紫菜提取物可降低白细胞介素(interleukin-1β,IL-1β)水平(P<0.05);不同干预组的胰腺组织病理结果较模型对照组有所改善,β细胞数量增多。在氧化应激方面,与模型对照组相比,100 mg/kg条斑紫菜提取物能够显著降低肝脏丙氨酸氨基转移酶和丙二醛(malondialdehyde, MDA)水平(P<0.05),400 mg/kg条斑紫菜提取物可以显著增加谷胱甘肽过氧化物酶(glutathione peroxidase, GSH-Px)和过氧化氢酶(catalase, CAT)水平(P<0.05)。结论 条斑紫菜提取物对1型糖尿病小鼠的肝脏氧化性损伤的保护作用,可通过调节CAT和GSH-Px活性、降低MDA含量实现的。条斑紫菜提取物还可通过降低肝脏TNF-α和IL-1β水平,从而改善肝脏炎症反应。

OBJECTIVE To study the effect of Porphyra yezoensis extract on liver inflammation and oxidative stress in type 1 diabetics mice.METHODS A total of ninety-one C57BL/6J male mice were adaptively fed for two weeks,and twelve C57BL/6J male mice were randomly reserved to be included in the blank control group.The rest of the mice were fasted overnight for twelve hours(except water),and they were given 170.00 mg/kg streptozotocin by intraperitoneal injection.Fasting blood glucose in type 1 diabetics mice were greater than or equal to 16.7 mmol/L after seven days,and polydipsia,polyphagia,polyuria and weight loss appeared,which were judged to be the successful model of type 1 diabetes.Forty-eight successfully modeled mice were divided into the model control group,the low dose of Porphyra yezoensis extract group,the medium dose of Porphyra yezoensis extract and high dose of Porphyra yezoensis extract group according to the fasting blood glucose and body weight.The mice in the blank control group and the model group were given the same amount of normal saline.The low-dose,medium-dose,and high-dose intervention groups were separately given the corresponding dose of Porphyra yezoensis extract by intragastric administration for six weeks.The body weight of type 1 diabetic mice,changes in body length,fasting blood glucose,insulin,liver inflammatory factors and oxidative stress indicators and pathological sections of liver and pancreas after the intervention of Porphyra yezoensis extract were observed.The glucose oxidase method was used to determine the fasting blood glucose level of type 1 diabetic mice.The serum insulin content,liver inflammatory factor levels and oxidative stress indicators were detected by the enzyme-linked immunosorbent assay(ELISA).The hematoxylin-eosin staining method was used to observe histopathology of liver and pancreas paraffin sections.RESULTS The weight of the model control group was significantly lower than that of the blank control group(P<0.05),and the fasting blood glucose value was significantly higher than that of the blank control group(P<0.05).There was no statistical difference.In terms of inflammatory factors,compared with the model control group,low-dose Porphyra yezoensis extract can increase serum insulin levels and reduce liver tumor necrosis factor-α(TNF-α)levels(P<0.05)in T1DM mice,and medium-dose Porphyra yezoensis extract can reduce liver TNF-αlevel(P<0.05),high-dose Porphyra yezoensis extract can reduce the level of interleukin-1β(IL-1β)(P<0.05).The histopathological conditions of pancreas in different intervention groups were improved compared with the model control group,and the number of β cells increased compared with the model group.In terms of oxidative stress,compared with the model control group,low-dose Porphyra yezoensis extract can significantly reduce the levels of liver alanine aminotransferase(ALT)and malondialdehyde(MDA)(P<0.05),and high-dose Porphyra yezoensis extract can significantly increase the levels of glutathione peroxidase(GSH-Px)and catalase(CAT)(P<0.05).CONCLUSION The protective effect of Porphyra yezoensis extract on liver oxidative damage in T1 DM mice may be achieved by regulating the activity of CAT and GSH-Px and reducing the content of MDA.In addition,Porphyra yezoensis extract can reduce liver TNF-α and IL-1β levels to improve liver inflammation.