Ni Yung-Lun, Shen Huan-Ting, Lee Min-Wei, Yeh Kun-Lin, Chiang Chen-Yu, Kuan Yu-Hsiang
Department of Pulmonary Medicine, Taichung Tzu Chi Hospital, Buddhist Tzu Chi Medical Hospital, Taichung, Taiwan.
Institute of Biochemistry, Microbiology, and Immunology, Chung Shan Medical University, Taichung, Taiwan.
Tzu Chi Med J. 2020 Aug 6;32(4):344-350. doi: 10.4103/tcmj.tcmj_78_20. eCollection 2020 Oct-Dec.
Safrole, also called shikimol and Sassafras, is the carcinogenic and phenylpropanoid compound extracted from Sassafras tree and anise, betel, and camphor. Moreover, a high concentration of safrole can be occur in the saliva because of betel nut or areca quid chewing which a common habit observed in Southern and Southeastern Asia. Notably, macrophages are crucial phagocytic cells of the immune system. Nonetheless, to date, no evidence has been reported regarding safrole-induced proinflammatory response and the corresponding mechanism in macrophages.
In the present study, the cytokines expression, NO generation, protein phosphorylation, and expression were assessed by enzyme-linked immunosorbent assay, Griess reagent, and Western blot assay, respectively.
In this study, we determined that safrole induces the generation of nitric oxide and proinflammatory cytokines, including tumor necrosis factor-α, interleukin-1β, and IL-6 in RAW264.7 macrophages in a concentration-dependent manner. Furthermore, inhibitor of κB (IκB) degradation was caused by safrole in a concentration-dependent manner. In addition, the phosphorylation of nuclear factor (NF)-κB and mitogen-activated protein kinase (MAPK) family, including p38 MAPK, extracellular signal-regulated kinase (ERK), and c-Jun N-terminal kinase, was induced by safrole began to increase at 10 μM and attained a plateau at 100 μM.
These results indicated that safrole induces the expression of proinflammatory responses in macrophages through the NF-κB/IκB pathway and its upstream factor, MAPK family phosphorylation.
黄樟素，又称莽草酸和洋擦木素，是从洋擦木、茴芹、槟榔和樟脑中提取的具有致癌性的苯丙素类化合物。此外，由于咀嚼槟榔或蒌叶（南亚和东南亚地区的常见习惯），唾液中可能会出现高浓度的黄樟素。值得注意的是，巨噬细胞是免疫系统中至关重要的吞噬细胞。然而，迄今为止，尚未有关于黄樟素诱导巨噬细胞促炎反应及其相应机制的报道。
在本研究中，分别通过酶联免疫吸附测定、格里斯试剂和蛋白质印迹法评估细胞因子表达、一氧化氮生成、蛋白质磷酸化和表达情况。
在本研究中，我们确定黄樟素以浓度依赖性方式诱导RAW264.7巨噬细胞中一氧化氮和促炎细胞因子的生成，包括肿瘤坏死因子-α、白细胞介素-1β和白细胞介素-6。此外，黄樟素以浓度依赖性方式导致κB抑制蛋白（IκB）降解。此外，黄樟素诱导核因子（NF）-κB和丝裂原活化蛋白激酶（MAPK）家族（包括p38 MAPK、细胞外信号调节激酶（ERK）和c-Jun氨基末端激酶）的磷酸化，在10 μM时开始增加，在100 μM时达到平台期。
这些结果表明，黄樟素通过NF-κB/IκB途径及其上游因子MAPK家族磷酸化诱导巨噬细胞中促炎反应的表达。
