Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, 730000 Gansu, China.
Second Hospital of Lanzhou University Dingxi Hospital (Dingxi City People's Hospital) Clinical Laboratory, Dingxi, 743000 Gansu, China.
Oxid Med Cell Longev. 2021 Nov 10;2021:9877170. doi: 10.1155/2021/9877170. eCollection 2021.
Reactive oxygen species (ROS) are either toxic in excess or essential for redox signalling at the physiological level, which is closely related to the site of generation. Xanthohumol (XN) is an important natural product of hops ( L.) and was reported to induce ROS in mitochondria. While in the present study, our data indicate that NADPH oxidase (NOX) is another site. In human acute myeloid leukemia HL-60 cells, we first identified that cell proliferation was inhibited by XN without affecting viability, and this could be alleviated by the antioxidant N-acetyl-L-cysteine (NAC); cell cycles were blocked at G1 phase, apoptosis was induced in a dose-dependent manner, and malondialdehyde (MDA) content was upregulated. XN-induced ROS generation was detected by flow cytometry, which can be inhibited by diphenyleneiodonium chloride (DPI, a NOX inhibitor), while not by N-methyl-L-arginine acetate (L-NMMA, a nitric oxide synthase inhibitor). The involvement of NOX in XN-induced ROS generation was further evaluated: immunofluorescence assay indicated subunits assembled in the membrane, and gp91 knockdown with siRNA decreased XN-induced ROS. Human red blood cells (with NOX, without mitochondria) were further selected as a cell model, and the XN-induced ROS and DPI inhibiting effects were found again. In conclusion, our results indicate that XN exhibits antiproliferation effects through ROS-related mechanisms, and NOX is a source of XN-induced ROS. As NOX-sourced ROS are critical for phagocytosis, our findings may contribute to the anti-infection and anti-inflammatory effect of XN.
活性氧（ROS）在生理水平上要么过多有毒，要么对氧化还原信号至关重要，这与产生的部位密切相关。黄腐酚（XN）是啤酒花（ L.）的一种重要天然产物，据报道它能诱导线粒体中的 ROS。然而，在本研究中，我们的数据表明 NADPH 氧化酶（NOX）是另一个产生 ROS 的部位。在人急性髓系白血病 HL-60 细胞中，我们首先确定 XN 抑制细胞增殖而不影响细胞活力，而抗氧化剂 N-乙酰-L-半胱氨酸（NAC）可以缓解这种情况；细胞周期被阻滞在 G1 期，细胞凋亡呈剂量依赖性诱导，丙二醛（MDA）含量上调。通过流式细胞术检测到 XN 诱导的 ROS 产生，这种产生可以被二苯乙烯碘（DPI，一种 NOX 抑制剂）抑制，但不能被 N-甲基-L-精氨酸乙酸盐（L-NMMA，一种一氧化氮合酶抑制剂）抑制。进一步评估了 NOX 在 XN 诱导的 ROS 产生中的作用：免疫荧光分析表明亚基在膜上组装，并用 siRNA 敲低 gp91 可减少 XN 诱导的 ROS。进一步选择具有 NOX（无线粒体）的人红细胞作为细胞模型，再次发现 XN 诱导的 ROS 和 DPI 抑制作用。总之，我们的结果表明，XN 通过 ROS 相关机制表现出抗增殖作用，而 NOX 是 XN 诱导的 ROS 的来源。由于 NOX 来源的 ROS 对吞噬作用至关重要，我们的发现可能有助于 XN 的抗感染和抗炎作用。
