藁本内酯由亲电反应活性介导的Xenohormesis效应解析

Xenohormesis explains how secondary metabolites produced by environmentally stressed plants can confer survival benefits to animals that consume them. This principle holds that animals retain the ability to sense these stress-induced signaling molecules under nature selective pressure, which will activate the evolutionarily conserved cellular stress response and subsequently enhance their adaptation to adversity. Previously, we have discovered that there is a correlation between the feeding stress of Spodoptera litura (Fabricius) lavae and the accumulation of Z-ligustilide in Ligusticum chuanxiong Hort. In this study, we will dissect the Xenohormetic effect of Z-ligustilide via the activation of Nrf2-Keap1 pathway found in rat neuronal cells from an evolutionary and ecological perspective: Firstly, we will further clarify the influence of the feeding stress of Spodoptera litura (Fabricius) lavae on the accumulation Z-ligustilide; then, we will verify Z-ligustilide will exert disturbance and toxicity against Spodoptera litura (Fabricius) lavae and activate the TGA-SCL14 defensive pathway of Ligusticum chuanxiong Hort., which will constitute the inducing resistance of Ligusticum chuanxiong Hort.; Z-Ligustilide will be sensed by Spodoptera litura (Fabricius) lavae via stress sensitive protein Keap1, subsequently induce the defensive response regulated by Nrf2-Keap1 pathway, which will enhance the adaptation of Spodoptera litura (Fabricius) lavae to adversity; Finally, we will prove the activity of electrophilic reaction of Z-ligustilide is the key mediating factor among the whole process. After the tracing dissection, this study will enhance our understanding of the action mode and biological effect of Z-ligustilide and also offer a train of thought for exploring the essence of action of traditional Chinese medicine.

Xenohormesis效应解释了为何植物受逆境胁迫产生的次生代谢产物能提高取食动物的生存机会，认为在自然选择压力下动物保留着识别这些胁迫信号分子的能力，激活进化保守性细胞应激响应机制，提高逆境适应力。在发现斜纹夜蛾幼虫取食胁迫与川芎藁本内酯累积存在关联的基础上，本项目将从进化与生态角度考虑，解析藁本内酯经激活大鼠神经细胞Nrf2-Keap1通路发挥的Xenhormesis效应：首先，进一步阐明斜纹夜蛾幼虫取食胁迫对藁本内酯累积的影响；再明确藁本内酯可干扰及毒杀斜纹夜蛾幼虫与激活川芎TGA-SCL14防御性通路，构成川芎诱导抗性；而斜纹夜蛾幼虫可经应激敏感蛋白Keap1识别藁本内酯，诱导Nrf2-Keap1通路调控的防御反应，提高逆境适应力；最后阐明藁本内酯亲电反应活性为介导此过程的关键因素。本项目经溯源解析，将提升对藁本内酯作用模式及生物效应的理解，亦为探究植物中药作用本质提了思路。

Xenohormesis效应解释了为何植物受逆境胁迫产生的次生代谢产物能提高取食动物的生存机会，认为在自然选择压力下动物保留着对这些胁迫信号分子作出反应的能力，激活进化保守性细胞应激响应机制，提高逆境适应力。本研究旨在以阐明植物中药成分是否在发挥生物活性时是否也遵循Xenohormesis 效应。本研究一方面探究藁本内酯在与斜纹夜蛾幼虫互作时是否遵循Xenohormesis效应，另一方面，在疾病相关细胞与动物模型上，藁本内酯是否可由激活细胞应激响应机制发挥Xenohormesis效应,提高机体对疾病的耐受性。重要结果：明确了斜纹夜蛾幼虫取食与川芎内藁本内酯的积累具相关性；发现藁本内酯对斜纹夜蛾幼虫的毒杀、拒食和抑制生长发育作用具有双相性，构效关系研究发现α, β, γ, δ-不饱和双键与羰基形成亲电子共轭结构是藁本内酯发挥作用的关键基础。同时，发现藁本内酯可调控斜纹夜蛾幼虫中肠的解毒代谢酶活性与表达，亦具双相性。发现藁本内酯可抑制卵巢SL细胞，且经氧化损伤诱导凋亡与周期阻滞有关。进一步发现藁本内酯低剂量预处理可提高斜纹夜蛾幼虫和卵巢SL细胞胁迫耐受性，符合Xenohormesis效应特征。在疾病相关细胞或动物模型上，发现藁本内酯可经激活细胞应激响应机制Nrf2通路与HSP70通路而发挥对脑缺血损伤的保护作用。发现藁本内酯通过表观遗传机制重新激活雌激素受体表达而恢复ER-乳腺癌细胞对他莫昔芬的敏感性，亦发现藁本内酯可经抑制自噬干扰DNA损伤修复机制恢复耐他莫昔芬乳腺癌细胞的敏感性。而且，还解析了含藁本内酯的中药复方桃红四物汤对脑缺血的保护作用亦是基于对抗氧化应激响应机制Nrf2信号通路的调控作用。此外，还发现人参皂苷Rh2、莪术醇、石菖蒲挥发油成分在抗肿瘤方面的作用均与细胞应激响应相关机制有关。已经发表学术论文13篇（SCI收录11篇，JCR一区论文4篇,申请发明专利两项，参加学术会议交流9次。意义：本项目将提升对藁本内酯作用模式及生物效应的理解，证实了中药Xenohormesis效应可为探究植物中药作用本质提了思路。