Zhu Pengyan, Wang Xinting, Liu XinLan, Shen Xiaojing, Li Ai, Zheng Xiaohong, Sheng Jun, Yuan Wenjuan
College of Science, Yunnan Agricultural University, Kunming 650201, China.
Key Laboratory of Puer Tea Science, Ministry of Education, Yunnan Agricultural University, Kunming 650201, China.
Foods. 2024 Sep 29;13(19):3116. doi: 10.3390/foods13193116.
flowers (DOF) have previously been established as a promising source of natural antioxidants, and it is ideally suited for processing to prepare functional foods and food additives. The precise extraction processes employed, however, can alter the composition and antioxidant properties of the resultant products, and the characteristic compounds associated with the active fractions prepared from DOF or their mechanisms of action have yet to be reported. To clarify the molecular mechanisms through which these active fractions function for the first time, chromatography was used to separate DOF extracts, yielding five fractions (Fr. (a-e)). Analyses of the antioxidant activity for these different fractions revealed that Fr. (d) presented with the most robust bioactivity. Levels of total flavonoids were then measured, revealing that antioxidant activity levels were positively correlated with total flavonoid content. Fr. (d) was found to contain 20 flavonoids in HPLC-Triple-TOF-MS/MS analyses. At the cellular level, Fr. (d) was found to induce increases in the levels of protective antioxidant factors (SOD and GSH-Px) while reducing the levels of reactive oxygen species (ROS), damage-associated factors (MDA, NO, TNF-α, IL-1β, and IL-6), and inducible nitric oxide synthase (iNOS) expression in C2C12 cells that had been stimulated with HO. These data thus provided support for Fr. (d) prevention of oxidative stress and inflammation. Network pharmacology analyses further suggested that Fr. (d) can help protect against oxidative stress through its effects on PI3K/Akt-related signaling activity. Fr. (d) was subsequently found to upregulate PI3K/Akt pathway-related proteins, nuclear transcription factor 2 (Nrf2), and heme oxygenase 1 (HO-1) in addition to suppressing Kelch-like epoxide-related protein 1 (Keap1) expression. In summary, Fr. (d) was found to suppress PI3K/Akt/Nrf2 pathway activation, ultimately alleviating inflammation and oxidative stress as predicted with a network pharmacology approach. Future studies aimed at clarifying the composition and mechanistic activity of DOF Fr. (d) will likely help establish it as a functional food capable of promoting health and longevity.
花（DOF）此前已被确立为天然抗氧化剂的一个有前景的来源，并且它非常适合加工以制备功能性食品和食品添加剂。然而，所采用的精确提取工艺会改变所得产品的成分和抗氧化性能，与从DOF制备的活性组分相关的特征化合物或其作用机制尚未见报道。为了首次阐明这些活性组分发挥作用的分子机制，采用色谱法分离DOF提取物，得到五个组分（组分（a - e））。对这些不同组分的抗氧化活性分析表明，组分（d）具有最强的生物活性。随后测量了总黄酮水平，结果表明抗氧化活性水平与总黄酮含量呈正相关。在HPLC - 三重四极杆飞行时间串联质谱分析中发现组分（d）含有20种黄酮类化合物。在细胞水平上，发现组分（d）能诱导保护性抗氧化因子（超氧化物歧化酶和谷胱甘肽过氧化物酶）水平升高，同时降低活性氧（ROS）、损伤相关因子（丙二醛、一氧化氮、肿瘤坏死因子 - α、白细胞介素 - 1β和白细胞介素 - 6）的水平以及经HO刺激的C2C12细胞中诱导型一氧化氮合酶（iNOS）的表达。这些数据因此为组分（d）预防氧化应激和炎症提供了支持。网络药理学分析进一步表明，组分（d）可通过其对PI3K/Akt相关信号活性的影响来帮助抵御氧化应激。随后发现组分（d）除了抑制类kelch环氧相关蛋白1（Keap1）的表达外，还上调PI3K/Akt途径相关蛋白、核转录因子2（Nrf2）和血红素加氧酶1（HO - 1）。总之，发现组分（d）抑制PI3K/Akt/Nrf2途径的激活，最终如网络药理学方法所预测的那样减轻炎症和氧化应激。旨在阐明DOF组分（d）的组成和作用机制活性的未来研究可能有助于将其确立为一种能够促进健康和长寿的功能性食品。
