Otonecine型吡咯里西啶生物碱clivorine的代谢规律及致毒机制的多样性与川紫菀用药安全的再评价

Pyrrolizidine alkaloids (PAs) are one of the most common naturally-occurring phytotoxins. The toxic PAs usually include retronecine and otonecine types. Both types have been successively found in many traditional Chinese medicinal herbs (CMHs), which structures, metabolism and toxic mechanism have been studied. However, most studies focused on the retronecine-type PAs, studies on the otonecine-type PAs and related CMHs are largely underappreciated. Clivorine is a representative otonecine-type PA found in many CMHs. In our previous studies, clivorine could be metabolized by various enzymes in microsomes and induce liver cell damage through diverse molecular pathways, such as necrosis, apoptosis and autophagy, which may be attributed to the complexity and diversity of the metabolism and toxicity of otonecine-type PAs in vivo. As for the otonecine-type PA-containing CMHs, it may be the more likely case. In this project, both metabolic and the molecular toxicological mechanisms of the otonecine-type PAs will be further studied using clivorine as an example. Furthermore, Chuan Zi Wan (Ligulariae Radix et Rhizoma), which contain the otonecine-type PAs, will be used as the paradigm and studied by chemical and metabolic fingerprints of PAs, analyses of metabolomics and integrated TD/TK characteristics, so as to uncover the real substances and mechanism responsible for its potential toxicity and provide the scientific bases for further comprehensive and systematic evaluation and better understanding of the safety of this herb in Chinese medical practices.

吡咯里西啶生物碱（PAs）是中草药中一类较常见的肝毒性成分，其主要结构类型包括retronecine型和otonecine型。目前，对otonecine型PAs及其相关中草药的代谢规律、致（解）毒机制的研究仍较少或未能深入。Clivorine是一具有代表性的otonecine型PA。我们前期研究发现，该碱受微粒体中多种代谢酶的作用，并可能通过多种途径（如：坏死、凋亡和自噬）导致肝细胞损伤，提示了otonecine型PAs体内代谢与毒性的复杂性和多样性。本项目拟对此现象进一步展开研究，力图深入地认识其代谢规律及分子毒理机制的多样性；并在此基础之上，以含该类成分的川紫菀药材为范例，通过PAs化学指纹、体内外代谢指纹、代谢组学分析和基于中药整体论多组分整合毒效/毒代动力学特征的解析，以了解该药材潜在毒性的物质基础及可能的作用机制，为进一步系统评价该药材的用药风险和指导临床安全用药提供科学依据。

吡咯里西啶生物碱是中草药中一类较常见的肝毒性成分，但迄今对其致（解）毒机制的了解仍较少。本项目对川紫菀及所含otonecine型肝毒吡咯里西啶生物碱成分clivorine的体内外代谢与致毒机制的多样性进行了深入研究，其主要内容为：川紫菀及clivorine的代谢规律解析及其毒理学意义；clivorine对肝细胞毒性及其作用机制的考察；非吡咯里西啶生物碱成分对clivorine代谢与毒性的干预及内源性拮抗物质的研究；不同含吡咯里西啶生物碱中草药肝毒性作用机制的比较研究。经过研究和探索，本项目发现了一些新颖且独特的实验现象，揭示了otonecine型吡咯里西啶生物碱clivorine受体内多种代谢酶的活化或失活作用，并通过多种细胞机制（坏死、凋亡和自噬）导致肝细胞损伤。同时，研究还发现川紫菀多糖等成分对川紫菀吡咯里西啶生物碱具有潜在的干预及解毒作用。本项目研究不仅加深了对otonecine型吡咯里西啶生物碱的代谢规律与致毒机制多样性的了解，而且为含该类生物碱中草药的安全性评价提供了理论基础。本项目已发表研究论文7篇，其中5篇论文为SCI期刊收录，2篇为中文核心期刊收录。培养硕士研究生6名，已获得学位4名。