Yao Jie, Chen Yiguo, Wang Ning, Jiang Dongneng, Zheng Jiang
*Medical Research Center, Southwest Hospital, Third Military Medical University, Chongqing 400038, People's Republic of China.
Biosci Rep. 2014 May 23;34(3):e00109. doi: 10.1042/BSR20130103.
LPS (lipopolysaccharide), an outer membrane component of Gram-negative bacteria, plays an important role in the pathogenesis of sepsis and lipid A is known to be essential for its toxicity. Therefore it could be an effective measure to prevent sepsis by neutralizing or destroying LPS. Numerous studies have indicated that many traditional Chinese medicines are natural antagonists of LPS in vitro and in vivo. The goal of this study is to develop a rapid method to screen anti-sepsis components from Chinese herbs by use of a direct lipid A-based affinity biosensor technology based on a resonant mirror. The detergent OG (n-octyl β-D-glucopyranoside) was immobilized on a planar non-derivatized cuvette which provided an alternative surface to bind the terminal hydrophilic group of lipid A. A total of 78 herbs were screened based on the affinity biosensor with a target of lipid A. The aqueous extract of PSA (Paeonia suffruticosa Andr) was found to possess the highest capability of binding lipid A. Therefore an aqueous extraction from this plant was investigated further by our affinity biosensor, polyamide chromatography and IEC-HPLC. Finally, we obtained a component (PSA-I-3) from Paeonia suffruticosa Andr that was evaluated with the affinity biosensor. We also studied the biological activities of PSA-I-3 against sepsis in vitro and in vivo to further confirm the component we screened with the biosensor. In vitro, we found that PSA-I-3 could decrease TNFα (tumour necrosis factor α) release from RAW264.7 cells induced by LPS in a dose-dependent manner. In vivo, it increased remarkably the survival of KM (KunMing) mice by challenging both lethal-dose LPS and heat-killed Escherichia coli compared with control groups. Our results suggest that the constructed affinity biosensor can successfully screen the anti-sepsis component from Chinese herbs.
脂多糖（LPS）是革兰氏阴性菌外膜的一种成分，在脓毒症发病机制中起重要作用，且已知脂质A对其毒性至关重要。因此，中和或破坏LPS可能是预防脓毒症的有效措施。众多研究表明，许多传统中药在体外和体内都是LPS的天然拮抗剂。本研究的目的是利用基于共振镜的直接脂质A亲和生物传感器技术，开发一种从中药中筛选抗脓毒症成分的快速方法。去污剂OG（正辛基β-D-葡萄糖苷）固定在平面未衍生化的比色皿上，该比色皿提供了一个替代表面来结合脂质A的末端亲水基团。基于脂质A靶点的亲和生物传感器共筛选了78种草药。发现牡丹皮水提取物具有最高的结合脂质A的能力。因此，我们通过亲和生物传感器、聚酰胺色谱和离子交换高效液相色谱对该植物的水提取物进行了进一步研究。最后，我们从牡丹皮中获得了一种成分（PSA-I-3），并用亲和生物传感器对其进行了评估。我们还研究了PSA-I-3在体外和体内对脓毒症的生物活性，以进一步确认我们用生物传感器筛选出的成分。在体外，我们发现PSA-I-3能以剂量依赖的方式降低LPS诱导的RAW264.7细胞中肿瘤坏死因子α（TNFα）的释放。在体内，与对照组相比，通过挑战致死剂量的LPS和热灭活的大肠杆菌，它显著提高了昆明小鼠的存活率。我们的结果表明，构建的亲和生物传感器能够成功地从中药中筛选出抗脓毒症成分。
