山奈酚通过抑制 NF-κB、阻断 TLR4 通路和减少 ROS 生成来减轻脂多糖诱导的 BV2 小胶质细胞炎症反应。
Isorhamnetin alleviates lipopolysaccharide-induced inflammatory responses in BV2 microglia by inactivating NF-κB, blocking the TLR4 pathway and reducing ROS generation.
机构信息
Department of Acupuncture and Moxibustion, Dongeui University College of Korean Medicine, Busan 47227, Republic of Korea.
School of Pharmaceutical Sciences, Institute of Drug Discovery and Development, Zhengzhou University, Zhengzhou, Henan 450001, P.R. China.
出版信息
Int J Mol Med. 2019 Feb;43(2):682-692. doi: 10.3892/ijmm.2018.3993. Epub 2018 Nov 20.
Isorhamnetin, which is a flavonoid predominantly found in fruits and leaves of various plants, including Hippophae rhamnoides L. and Oenanthe javanica (Blume) DC, is known to possess various pharmacological effects. However, the anti‑inflammatory potential of isorhamnetin remains poorly studied. Therefore, the present study aimed to investigate the inhibitory potential of isorhamnetin against inflammatory responses in lipopolysaccharide (LPS)‑stimulated BV2 microglia. To measure the effects of isorhamnetin on inflammatory mediators and cytokines, and reactive oxygen species (ROS) generation, the following methods were used: cell viability assay, griess assay, ELISA, reverse transcriptase‑polymerase chain reaction, flow cytometry, western blotting and immunofluorescence staining. The results revealed that isorhamnetin significantly suppressed LPS‑induced secretion of pro‑inflammatory mediators, including nitric oxide (NO) and prostaglandin E2, without exhibiting significant cytotoxicity. Consistent with these results, isorhamnetin inhibited LPS‑stimulated expression of regulatory enzymes, including inducible NO synthase and cyclooxygenase‑2 in BV2 cells. Isorhamnetin also downregulated LPS‑induced production and expression of pro‑inflammatory cytokines, such as tumor necrosis factor‑α and interleukin‑1β. The mechanism underlying the anti‑inflammatory effects of isorhamnetin was subsequently evaluated; this flavonoid inhibited the nuclear factor (NF)‑κB signaling pathway by disrupting degradation and phosphorylation of inhibitor κB‑α in the cytoplasm and blocking translocation of NF‑κB p65 into the nucleus. In addition, isorhamnetin effectively suppressed LPS‑induced expression of Toll‑like receptor 4 (TLR4) and myeloid differentiation factor 88. It also suppressed the binding of LPS with TLR4 in BV2 cells. Furthermore, isorhamnetin markedly reduced LPS‑induced generation of ROS in BV2 cells, thus indicating a strong antioxidative effect. Collectively, these results suggested that isorhamnetin may suppress LPS‑mediated inflammatory action in BV2 microglia through inactivating the NF‑κB signaling pathway, antagonizing TLR4 and eliminating ROS accumulation. Further studies are required to fully understand the anti‑inflammatory effects associated with the antioxidant capacity of isorhamnetin; however, the findings of the present study suggested that isorhamnetin may have potential benefits in inhibiting the onset and treatment of neuroinflammatory diseases.
山柰酚是一种主要存在于各种植物的果实和叶子中的类黄酮,包括沙棘和獐牙菜(Blume)DC,已知具有多种药理作用。然而,山柰酚的抗炎潜力仍研究甚少。因此,本研究旨在探讨山柰酚对脂多糖(LPS)刺激的 BV2 小胶质细胞炎症反应的抑制潜力。为了测量山柰酚对炎症介质和细胞因子以及活性氧(ROS)生成的影响,采用了以下方法:细胞活力测定、格里斯测定、ELISA、逆转录-聚合酶链反应、流式细胞术、Western blot 和免疫荧光染色。结果显示,山柰酚显著抑制 LPS 诱导的促炎介质一氧化氮(NO)和前列腺素 E2 的分泌,同时没有表现出明显的细胞毒性。与这些结果一致,山柰酚抑制了 LPS 刺激的 BV2 细胞中诱导型一氧化氮合酶和环氧化酶-2 等调节酶的表达。山柰酚还下调了 LPS 诱导的促炎细胞因子如肿瘤坏死因子-α和白细胞介素-1β的产生和表达。随后评估了山柰酚抗炎作用的机制;这种类黄酮通过破坏细胞质中抑制剂 κB-α的降解和磷酸化以及阻止 NF-κB p65 向核内转位来抑制核因子(NF)-κB 信号通路。此外,山柰酚有效抑制 LPS 诱导的 Toll 样受体 4(TLR4)和髓样分化因子 88 的表达。它还抑制了 LPS 与 BV2 细胞中 TLR4 的结合。此外,山柰酚显著减少 LPS 诱导的 BV2 细胞中 ROS 的产生,从而表明其具有很强的抗氧化作用。总之,这些结果表明,山柰酚可能通过使 NF-κB 信号通路失活、拮抗 TLR4 和消除 ROS 积累来抑制 LPS 介导的 BV2 小胶质细胞中的炎症反应。需要进一步的研究来充分了解山柰酚的抗炎作用与其抗氧化能力之间的关系;然而,本研究的结果表明,山柰酚可能在抑制神经炎症性疾病的发病和治疗方面具有潜在的益处。