Xiao Zhiyong, Zhou Wenxia, Zhang Yongxiang
Beijing Institute of Pharmacology and Toxicology, Beijing, China; State Key Laboratory of Toxicology and Medical Countermeasures, Beijing, China.
Beijing Institute of Pharmacology and Toxicology, Beijing, China; State Key Laboratory of Toxicology and Medical Countermeasures, Beijing, China.
Adv Pharmacol. 2020;87:277-299. doi: 10.1016/bs.apha.2019.08.003. Epub 2019 Oct 18.
Fungal bioactive polysaccharides are well known and have been widely used in Asia as a part of the traditional diet and medicine. In fact, some biopolymers (mainly β-glucans or glycoconjugate) have already made their way to the market as antitumor or immunostimulating drugs. In the last decades, the relationship between structure and activity of polysaccharides and their detailed mode of action have been the core of intense research to understand and utilize their medicinal properties. Most of the antitumor polysaccharides belong to conserved β-glucans, with a linear β-(1→3)-glucan backbone and attached β-(1→6) branch. Structurally different β-glucans appear to have different affinities toward their receptors and thus generate markedly different host responses. However, their antitumor activities are mainly influenced by molecular mass, degree of branching, conformation, and structure modification of the polysaccharides. β-Glucans act on several immune receptors including Dectin-1, complement receptor (CR3) and TLR-2/6, then trigger both innate and adaptive response and enhance opsonic and nonopsonic phagocytosis. Various receptor interactions explain the possible mode of actions of polysaccharides.
真菌生物活性多糖广为人知，在亚洲已作为传统饮食和药物的一部分被广泛使用。事实上，一些生物聚合物（主要是β-葡聚糖或糖缀合物）已作为抗肿瘤或免疫刺激药物进入市场。在过去几十年中，多糖的结构与活性之间的关系及其详细作用方式一直是深入研究的核心内容，旨在了解和利用它们的药用特性。大多数抗肿瘤多糖属于保守的β-葡聚糖，具有线性β-(1→3)-葡聚糖主链和连接的β-(1→6)分支。结构不同的β-葡聚糖对其受体似乎具有不同的亲和力，因此会产生明显不同的宿主反应。然而，它们的抗肿瘤活性主要受多糖的分子量、分支度、构象和结构修饰的影响。β-葡聚糖作用于多种免疫受体，包括Dectin-1、补体受体（CR3）和TLR-2/6，然后触发先天性和适应性反应，并增强调理吞噬作用和非调理吞噬作用。各种受体相互作用解释了多糖可能的作用方式。
