传感器类型
其他(光学生物传感器)
检测对象
脂质A结合活性成分(lipid A-binding components;样品基质:中药水提物 aqueous extract 及 HPLC 分离组分 TCR1/TCR2/TCR3)
检测原理
该传感方法以脂质A为固定识别元件,将其按厂家说明固定于疏水比色皿表面。中药水提物或 HPLC 分离组分 TCR1、TCR2、TCR3 加入含 PBS 的比色皿中,其中能与脂质A结合的活性成分与表面脂质A发生结合。结合事件改变比色皿表面的界面质量与局部折射率;光学检测系统对单角折射率变化高度敏感,折射率 n1 的微小变化会引起导波角 θguide 的较大变化。随后用 PBS、0.1 M HCl 和 10 mM NaOH 交替洗涤去除未结合物质,FASTplot 软件分析结合曲线。被测物结合能力越强,θguide 变化越大,从而比较不同草药或组分对脂质A的结合活性。
检测灵敏度
原文未报告
效应效果
选择性方面,作者以脂质A为靶标从78味中药中筛出12味高结合活性草药,诃子(Terminalia chebula Retz)结合能力最高;经阳离子交换树脂和 HPLC 分离得到 TCR1、TCR2、TCR3,其中 TCR3 结合脂质A能力最强。体外鲎试验中,TCR3 10、20、40、80 μg/ml 与 10 ng/ml LPS 孵育后,可剂量依赖抑制 LAL 凝集,与 LPS 组比较 P<0.01;ELISA 显示 TCR3 剂量依赖抑制 LPS 诱导 RAW264.7 细胞释放 TNFα,P<0.05 或 P<0.01。体内 50 mg/kg TCR3 可保护小鼠免受 20 mg/kg LPS 或 1.2×10^10 CFU/kg 热灭活大肠杆菌致死攻击,单独给药无死亡,提示无明显毒性。原文未报告 RSD、稳定性、回收率及与 ELISA/HPLC 的定量对比。
传感器的构成
- 基底/换能器:疏水比色皿(hydrophobic cuvette,Thermo Labsystems),提供脂质A固定表面并作为光学检测界面。
- 识别元件:脂质A(lipid A),按厂家说明固定于比色皿表面,用于捕获能结合脂质A的草药活性成分。
- 孵育介质:PBS,用于加入中药水提物或 TCR 组分并维持结合反应环境。
- 洗涤介质:0.1 M HCl、PBS、10 mM NaOH,交替洗涤以去除未结合或非特异结合物质。
- 信号读出:光学检测(optic principle),监测结合引起的界面折射率变化及导波角 θguide 变化,FASTplot 软件分析。
中文摘要
许多临床实验和研究表明,传统中药具有抗脓毒症的潜力。本文以脂多糖(LPS)毒性核心脂质A(lipid A)为靶标,利用生物传感器技术筛选78味中药,发现诃子(Terminalia chebula Retz)结合脂质A的能力最高。随后采用阳离子交换树脂(CER)和高效液相色谱(HPLC)从诃子中分离得到三种活性组分,分别命名为 TCR1、TCR2 和 TCR3,并用生物传感器评价其结合脂质A的能力,结果显示 TCR3 的结合能力最强。体外实验表明,TCR3 可显著抑制 LPS 诱导的鲎变形细胞裂解物(LAL)凝集,并剂量依赖地降低 LPS 诱导 RAW264.7 细胞释放肿瘤坏死因子α(TNFα)。体内实验显示,TCR3 可剂量依赖地保护小鼠免受致死剂量 LPS 和热灭活大肠杆菌35218的攻击。结果表明,诃子是一种重要的中和 LPS 的中药,具有作为脓毒症治疗药物的潜力。
英文摘要
Many clinical experiments and studies have demonstrated that traditional Chinese medicines possess the capacity for being used in anti-sepsis. In this paper, we screened 78 herbs based on biosensor technology by targeting of lipid A. Terminaliachebula Retz was found to possess the highest capability of binding lipid A. With CER (cation-exchange resin) and HPLC, we obtained three active components extracted from Terminaliachebula Retz, and named them TCR1, TCR2 and TCR3 respectively. These three components were evaluated with the biosensor, and it was found that the TCR3 was the most capable candidate to bind lipid A. We also studied the biological activities of TCR3 against sepsis in vitro and in vivo. in vitro, TCR3 could significantly inhibit LPS (lipopolysaccharide)-induced LAL (Limulus amoebocyte lysate)) from agglutination and decrease TNFalpha (tumour necrosis factor alpha) release from RAW264.7 cells induced by LPS in a dose-dependent manner. in vivo, TCR3 could significantly protect mice against a lethal challenge with LPS and heat-killed Escherichia coli 35218 in a dose-dependent manner. These results demonstrate that Terminaliachebula Retz is an important herb to neutralize LPS and it has the potential to serve as a treatment for sepsis.