Department of Medical Science, Catholic Kwandong University College of Medicine, Gangneung, Gangwon-do, Korea.
Department of Medical Science, Catholic Kwandong University College of Medicine, Gangneung, Gangwon-do, Korea; The Convergence Institute of Healthcare and Medical Science, Catholic Kwandong University, International St. Mary's Hospital, Incheon, Korea.
Phytomedicine. 2023 Jan;108:154486. doi: 10.1016/j.phymed.2022.154486. Epub 2022 Oct 3.
Microglia are innate immune cells in the central nervous system that play a crucial role in neuroprotection by releasing neurotrophic factors, removing pathogens through phagocytosis, and regulating brain homeostasis. The constituents extracted from the roots and stems of the Daphne genkwa plant have shown neuroprotective effects in an animal model of Parkinson's disease. However, the effect of Daphne genkwa plant extract on microglia has yet to be demonstrated.
To study the anti-inflammatory and neuroprotective effects of Daphne genkwa flower extract (GFE) in microglia and explore the underlying mechanisms.
In-vitro mRNA expression levels of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), inducible nitric oxide synthase, Arginase1, and brain derived neurotropic factor (BDNF) were analyzed by reverse transcription polymerase chain reaction in microglia cells. Nitric oxide (NO) and TNF-α protein were respectively analyzed by Griess reagent and Enzyme Linked Immunosorbent Assay. Immunoreactivity of Iba-1, Neu-N, and BDNF in mouse brain were analyzed by immunofluorescence staining. Phagocytosis capacity of microglia was examined using fluorescent zymosan-red particles.
GFE significantly inhibited lipopolysaccharide (LPS)-induced neuroinflammation and promoted neuroprotection both in vitro and in vivo. First, GFE inhibited the LPS-induced inflammatory factors NO, iNOS, and TNF-α in microglial cell lines and primary glial cells, thus demonstrating anti-inflammatory effects. Arginase1 and BDNF mRNA levels were increased in primary glial cells treated with GFE. Phagocytosis was also increased in microglia treated with GFE, suggesting a neuroprotective effect of GFE. In vivo, neuroprotective and anti-neuroinflammatory effects of GFE were also found in the mouse brain, as oral administration of GFE significantly inhibited LPS-induced neuronal loss and inflammatory activation of microglia.
GFE has anti-inflammatory effects and promotes microglial neuroprotective effects. GFE inhibited the pro-inflammatory mediators and enhanced neuroprotective microglia activity by increasing BDNF expression and phagocytosis. These novel findings of the GFE effect on microglia show an innovative approach that can potentially promote neuroprotection for the prevention of neurodegenerative diseases.
小胶质细胞是中枢神经系统中的固有免疫细胞，通过释放神经营养因子、通过吞噬作用清除病原体以及调节脑内平衡，在神经保护中发挥着关键作用。从瑞香科芫花属植物的根和茎中提取的成分在帕金森病动物模型中显示出神经保护作用。然而，芫花植物提取物对小胶质细胞的影响尚未得到证实。
研究芫花（GFE）提取物对小胶质细胞的抗炎和神经保护作用，并探讨其潜在机制。
采用逆转录聚合酶链反应（RT-PCR）分析体外小胶质细胞肿瘤坏死因子-α（TNF-α）、白细胞介素-1β（IL-1β）、诱导型一氧化氮合酶（iNOS）、精氨酸酶 1 和脑源性神经营养因子（BDNF）的 mRNA 表达水平。用 Griess 试剂和酶联免疫吸附试验（ELISA）分别分析一氧化氮（NO）和 TNF-α 蛋白。通过免疫荧光染色分析小鼠脑内 Iba-1、Neu-N 和 BDNF 的免疫反应性。用荧光酵母聚糖红颗粒检测小胶质细胞的吞噬能力。
GFE 显著抑制脂多糖（LPS）诱导的神经炎症，并在体内和体外均具有神经保护作用。首先，GFE 抑制 LPS 诱导的小胶质细胞系和原代神经胶质细胞中的炎症因子 NO、iNOS 和 TNF-α，从而发挥抗炎作用。GFE 处理的原代神经胶质细胞中 Arginase1 和 BDNF 的 mRNA 水平增加。用 GFE 处理的小胶质细胞的吞噬作用也增加，表明 GFE 具有神经保护作用。在体内，GFE 也在小鼠脑中表现出神经保护和抗炎作用，因为口服 GFE 可显著抑制 LPS 诱导的神经元丢失和小胶质细胞的炎症激活。
GFE 具有抗炎作用，并促进小胶质细胞的神经保护作用。GFE 通过增加 BDNF 表达和吞噬作用抑制促炎介质并增强神经保护小胶质细胞活性。这些关于 GFE 对小胶质细胞作用的新发现表明，这是一种潜在的创新方法，可促进神经保护以预防神经退行性疾病。
