山苍子果多酚对HepG2细胞氧化应激的缓解作用

Alleviating Effects of Polyphenols from Litsea cubeba Fruits against Oxidative Stress in HepG2 Cells

摘要:

为探究山苍子果多酚对细胞氧化应激的缓解作用，该文以山苍子鲜果及干果为原料，采用福林酚法分析两者多酚含量；采用ORAC、PSC法评估其体外抗氧化活性；通过H?O?诱导的HepG2细胞氧化应激模型探究了山苍子果多酚对细胞氧化应激损伤的缓解作用及机制。结果表明，鲜果总多酚（2053.29 mg GAE/100 g）含量为干果（411.47 mg GAE/100 g）的4.99倍，且约90%为游离态。鲜果多酚的抗氧化活性比干果更强，其ORAC、PSC值均高于干果多酚。高质量浓度山苍子果多酚将氧化损伤的HepG2细胞存活率提高2~3倍，同时显著提升SOD、CAT、GSH含量，降低LDH和ROS水平。分子机制表明，山苍子果多酚激活调节Nrf2/NQO1信号通路及上调其下游抗氧化酶SOD1、CAT、GSS的基因表达来发挥抗氧化应激作用。上述结果为山苍子果多酚在功能性食品中的应用提供了理论基础。

Abstract:

To investigate the alleviative effect of polyphenols from Litsea cubeba fruits on cellular oxidative stress, fresh and dried fruits were used as raw materials in this study. The polyphenol content was analyzed by the Folin-Ciocalteu method, while the in vitro antioxidant activity was evaluated using ORAC and PSC assays. An oxidative stress model of HepG2 cells induced by H2O2 was established to explore the protective mechanism of Litsea cubeba fruit polyphenols against oxidative damage. The results indicated that the total polyphenol content of fresh fruits (2053.29 mg GAE/100 g) was 4.99 times higher than that of dried fruits (411.47 mg GAE/100 g), with approximately 90% existing in free form. The antioxidant activity of fresh fruit polyphenols was significantly stronger than that of dried fruits, with higher ORAC/PSC values. High mass concentrations of Litsea cubeba fruit polyphenols increased the viability of oxidatively damaged HepG2 cells by 2~3 times, while significantly enhancing SOD, CAT, and GSH levels and reducing LDH and ROS levels. At the molecular level, it was demonstrated that the polyphenols activated the Nrf2/NQO1 signaling pathway and upregulated the gene expression of downstream antioxidant enzymes (SOD1, CAT, and GSS), thereby exerting antioxidative effects. These findings provide a theoretical foundation for the application of Litsea cubeba fruit polyphenols in functional foods.