沙棘果提取物对血糖调节受损人群血糖调控的影响及细胞糖代谢机制研究

Recent years, the rapid increasing prevalence of diabetes mellitus in China has brought a heavy disease burden to the country and the people. The diet is an important factor for blood glucose control. Sea buckthorn (Hippophae rhamnoides L) fruit contains many phytochemicals, such as quebrachitol and polyphenols, which have the effects of lowering the plasma glucose and total cholesterol as well as the effects of antioxidation and anti-inflammatory in animal experiments. The previous studies on cholesterol also demonstrated that the sea buckthorn fruits could improve the fasting plasma glucose. However, most of the existing researches were performed for healthy people or type 1 diabetes mellitus, the intervention studies for type 2 diabetes mellitus and impaired glucose regulation (prediabetes) were rare. Moreover, the studies on the absorption, distribution or excretion of the active ingredients of sea buckthorn in human were limited. To explore the effects and mechanism of sea buckthorn and its active ingredients on blood glucose metabolism, this study intends to recruit 120 prediabetes people, who will be randomly divided into 2 groups and given the sea buckthorn extract and placebo for 90 days. The metabolic outcome of sea buckthorn fruit extract in blood, urine and fecal as well as the changes of glucose and insulin will be analyzed. At the same time, the effects of sea buckthorn fruits extract on inflammatory factors such as IL-6、TNF-α、MCP-1 and antioxidant indices such as SOD、GSH、MDA in human will be observed. Furthermore, the effects of the important ingredients of sea buckthorn, isorhamnetin, on glucose metabolism will be studied in vitro to explore its molecular mechanism of lowering plasma glucose. The study is aimed at providing the evidence for the clinical prevention of type 2 diabetes mellitus using sea buckthorn fruit.

近年来中国糖尿病患病率的快速上升给国家和个人带来沉重医疗负担。膳食因素对于血糖调控非常重要。沙棘是药食同源的浆果类植物，其果汁含有丰富的白雀木醇、多酚等活性成分，动物实验证实其降血糖、降血脂、抗氧化、抗炎等作用，前期的沙棘果对胆固醇干预研究发现其可改善空腹血糖。但已有研究多针对健康人和1型糖尿病，缺乏对2型糖尿病及糖调节受损人群的干预及沙棘活性成分在人体内吸收、分布、代谢研究。为探究沙棘及其活性成分的血糖调控作用及机制，本研究拟招募糖调节受损者120人，随机分为2组，给予沙棘果提取物及安慰剂90天，分析血、尿、粪便中沙棘活性成分的代谢转归及血糖和胰岛素变化，同时研究沙棘提取物对人体内炎症因子如IL-6、TNF-α、MCP-1及抗氧化指标如SOD、GSH、MDA的影响；此外，通过体外实验探索沙棘中活性成分异鼠李素对糖代谢的影响，探讨其降血糖的分子机制，为沙棘果用于预防2型糖尿病提供科学依据。

糖调节受损（Impaired Glucose Regulation，IGR）是2型糖尿病发生前的必经阶段，具有隐匿性和可逆性，膳食因素具有重要的调控作用。本课题采用两阶段随机交叉对照设计，探究沙棘及其活性成分对IGR人群血糖代谢及其他健康作用的影响。. 研究共纳入符合标准的志愿者38位，随机分为AB组（16人）和BA组（22人）。AB组饮用沙棘全果浆35天（90mL/d），洗脱28天，再饮用安慰剂35天（90mL/d）；BA组干预顺序相反。在两阶段干预前后进行随访（共4次），问卷调查膳食及体力活动等情况；采集空腹及餐后血液样本，进行生化检测及非靶向代谢组学分析；测量体格指标及体成分等。采用意向性分析和优效性检验进行统计分析。. 沙棘全果浆具有良好的安全性和耐受性。沙棘干预35天后，IGR人群的空腹血糖（Fasting Plasma Glucose，FPG）降低，干预效应优于安慰剂且有统计学差异。沙棘组餐后胰岛素曲线下面积有优于安慰剂的倾向。两组餐后血糖曲线下面积、糖化血红蛋白、糖化血清蛋白、空腹胰岛素（Fasting Insulin，FINS）及相关指数、空腹C肽（C-peptide，CP）、超敏C反应蛋白、白细胞介素-6和肿瘤坏死因子-α、身体测量指标和体成分之间的差异均无统计学意义。. 洗脱期间，沙棘组FPG降低，安慰剂组升高，差异具有统计学显著性。此外，沙棘组FINS、空腹CP有优于安慰剂的倾向，女性体重、身体质量指数有所降低，干预效应显著。. 选取干预前后的空腹、餐后血清样本共计304个，基于LC-QTOF平台，进行代谢组定性和定量分析。正离子模式下共检测到代谢物3,838个，负离子模式下检测到代谢物2,312个。采取将差异倍数、t检验的P值和OPLS-DA模型的VIP值相结合的方法对差异代谢物进行筛选，结果干预后沙棘组、安慰剂组的差异代谢物主要包括黄酮类、糖苷类、氨基酸、有机酸等。将这些代谢物映射到KEGG（Kyoto Encyclopedia of Genes and Genomes）数据库，发现主要集中在氨基酸代谢、氨基糖和核苷酸糖代谢、乙醛酸和二羧酸代谢、花生四烯酸代谢、酮体的合成与降解等途径。. 本研究提示沙棘对IGR人群的血糖相关代谢具有一定的改善作用，为沙棘的开发、利用提供了一定的理论依据。