黄酮类化合物大多具有很强的抗氧化应激作用，研究表明这种作用与其调控不同的细胞信号通路分子及抗氧化酶的表达有关。槲皮素和儿茶素是食品中广泛存在且含量丰富的黄酮类成分。我们前期研究发现，两者在抵御过氧化氢诱导的HepG2细胞氧化应激中存在显著的协同效应，随后通过RNA-seq技术筛选出7个转录因子可能与协同作用有关，但具体的信号通路和作用靶点尚不清楚。本项目拟从筛选的转录因子入手，采用基因沉默、RT-PCR、Western Blot等技术，明确槲皮素与儿茶素协同保护细胞抗氧化应激的信号通路和靶基因；通过生物信息学分析，结合免疫共沉淀和双分子荧光互补等技术，揭示槲皮素与儿茶素协同调控的信号通路之间的交互作用关系。研究结果将为阐明槲皮素和儿茶素协同抗氧化的分子机制提供理论依据，也为探明黄酮类化合物之间的交互作用关系提供理论参考。

Many flavonoids can protect cells against oxidative stress, which is linked to their regulation on different signaling pathway molecules and antioxidant enzymes. Quercetin and (+)-catechin, two well-known flavonoids, are rich and distributed widely in dietary. Our previous study showed that both are able to protect synergistically HepG2 cell against H2O2-induced oxidative stress. Furthermore, seven potential transcription factors were identified by RNA-seq technology. However, the signal pathway and target genes involved remain unclear. The objective of this study is to further identify the signal pathway(s) and target genes involved in protective effects of quercetin and (+)-catechin on HepG2 cells against H2O2-induced oxidative stress by multiple experimental methods (such as gene silencing, Real-time PCR, Western Blot and fluorescence staining). The influence of quercetin and catechin on possible interactive actions between different signal pathways will be investigated based on bioinformatics analysis, Co-immunoprecipitation (CO-IP) and bimolecular fluorescence complementation (BIFC). These results will contribute a theoretical basis for understanding the molecular mechanism of antioxidant synergy of quercetin and catechin, and for elucidating the interactive effects among various flavonoids.