Anti-inflammatory glycosides from plants: Identification of cellular targets and examination of structure–function relationships

植物抗炎糖苷：细胞靶标的鉴定和结构与功能关系的检查

• 批准号: 407666933
• 负责人: Professor Dr. Hendrik Fuchs
• 金额: --
• 依托单位: Institut für Laboratoriumsmedizin, Klinische Chemie und Pathobiochemie (CVK)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2018
• 资助国家: 德国
• 起止时间: 2017-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/407666933?language=en
• 关键词: Anti; inflammatory; glycosides; plants; Identification

The unique diversity of plant glycosides harbors a considerable potential to derive a natural drug. In the past, we focused on the identification of glycosylated triterpenoids as endosomal escape enhancers in targeted tumor therapies. We identified a particular saponin, SO1861, from Saponaria officinalis L. and demonstrated in cell culture that tumor-targeted toxins can become enhanced in their cell killing efficacy up to 2,500,000-fold, which resulted in a broadening of the therapeutic window in mice between 10-fold to 500-fold. The tumor regression across all mouse studies was about 90% and the required dose was only 2% of the dose used for a treatment without SO1861. The lower dose resulted in decreased side effects and reduced immunogenicity. We demonstrated that the augmentative effect relies on an enhanced transfer of the toxin moiety across the membrane of the endocytic vesicle into the cytosol. It is important to emphasize that this specific outcome of SO1861 occurs at concentrations that are far below the concentration required to trigger general saponin effects (such as hemolysis) and is based on the particular and unique chemical structure of the aglycone and sugar chains.Investigations of anti-inflammatory saponins are of increasing interest. More than 25% of scientific papers on this topic are published within the last 4 years. There is no doubt that certain saponins have an anti-inflammatory potential, however, most investigations applied semi-purified saponin mixtures or total saponins, the results are descriptive and detailed knowledge on structure–function relationships is missing. It has not been shown to date, which molecules inside the cell are the targets of the saponins. It is hypothesized that the various anti-inflammatory effects of saponins are based on specific interactions that can be attributed to only a defined subgroup of saponins with particular chemical functionalities. We will first select commercially available saponins with known structure and described anti-inflammatory effects to identify primary cellular targets and to reveal structure–function relationships. In particular, we want to demonstrate how interactions between saponins and targets result in changes in the cytokine equipment. After confirming the anti-inflammatory effects of single saponins in cell culture, we will continue with labeling studies, binding assays, localization studies, inhibitor experiments, membrane assays and tracking of biological pathways. Identification and structural elucidation of new saponins with similar behavior will then be used to refine and generalize the observed molecular mechanisms. We will determine important structural characteristics (aglycone, composition of sugar residues, sugar linkage, stereoisomer configurations) by MALDI and NMR techniques. If successful, it is planned in a following period to investigate the molecular mechanism of the anti-inflammatory effects in vivo.

植物糖苷的独特多样性蕴藏着相当大的潜力，以获得天然药物。在过去，我们专注于鉴定糖基化三萜类化合物作为靶向肿瘤治疗中的内体逃逸增强剂。我们从肥皂草Saponaria officinalis L.中鉴定出一种特殊的皂甙SO 1861。并在细胞培养中证明，肿瘤靶向毒素的细胞杀伤效力可增强高达2，500，000倍，这导致小鼠的治疗窗口扩大10倍至500倍。所有小鼠研究中的肿瘤消退约为90%，所需剂量仅为不含SO 1861治疗所用剂量的2%。较低的剂量导致副作用减少和免疫原性降低。我们证明，增强效应依赖于增强的转移的毒素部分跨膜的内吞囊泡进入胞质溶胶。重要的是要强调，SO 1861的这种特定结果发生在远低于触发一般皂苷效应（如溶血）所需浓度的浓度下，并且基于糖苷配基和糖链的特殊和独特的化学结构。超过25%的关于这个主题的科学论文是在过去4年内发表的。毫无疑问，某些皂苷具有抗炎潜力，然而，大多数研究采用半纯化皂苷混合物或总皂苷，结果是描述性的，缺乏详细的结构-功能关系知识。到目前为止，还没有显示细胞内的哪些分子是皂苷的靶点。据推测，皂苷的各种抗炎作用是基于特定的相互作用，可以归因于只有一个特定的子组皂苷与特定的化学功能。我们将首先选择具有已知结构和描述的抗炎作用的市售皂苷，以鉴定主要细胞靶点并揭示结构-功能关系。特别是，我们想证明皂苷和目标之间的相互作用如何导致细胞因子设备的变化。在证实了单一皂苷在细胞培养中的抗炎作用后，我们将继续进行标记研究、结合测定、定位研究、抑制剂实验、膜测定和生物学途径的跟踪。具有类似行为的新皂苷的鉴定和结构阐明将用于精炼和概括所观察到的分子机制。我们将通过MALDI和NMR技术确定重要的结构特征（糖苷配基，糖残基的组成，糖键，立体异构体构型）。如果成功，计划在接下来的时间内研究体内抗炎作用的分子机制。