Investigation of the Inhibitory Mechanisms of N-hydroxycinnamoylphenalkylamides Analogues and Cinnamophilin on the Activation in Human Neutrophils and THP-1 Cells

• Main Authors: Yu-Hen Yeh, 葉宇涵
• Other Authors: 蕭哲志
• Format: Others
• Language: zh-TW
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/21541385443924832600

碩士 === 臺北醫學大學 === 醫學科學研究所 === 96 === In the human innate immune system, the neutrophils and monocytes are the key cellular elements and serve as a critical line of defense. There are many evidences indicate that neutrophils can degranulate and release many kinds of pro-inflammatory cytokines, proteinases and express chemotaxis toward invading microorganisms like bacteria, fungus, and virus, whereupon they engulf them through the process of phagocytosis. On the other hand, the monocytes also can differentiate to macrophages and provide a more powerful, long-term immunoreaction. These mediators which are released from leukocytes by tumor necrosis factor-alpha (TNF-??) and interleukin (IL). They activate a variety of gene expression, such as matrix metalloproteinases (MMPs) involved in tissue degradation. Nevertheless, when the normal regulatory mechanisms was failed, the reaction will get out of control and cause many inflammatory, autoimmune diseases, such as acute lung injury, rheumatoid arthritis and reperfusion injury. However, the neutrophils and monocytes in the circulatory system will be activated rapidly and excessively when the pathological changes happened, then cause tissue injury. The results here indicate that cinnamophilin extracted from herbal medicines and N-hydroxycinnamoylphenalkylamides analogues (EK8) showed obviously inhibitory effect on respiratory burst and MMPs activation in neutrophils and THP-1 cells. In this study, we found that cinnamophilin and EK8 was shown to inhibit the fMLP-induced superoxide production in neutrophils by chemiluminescence assay, but EK8 not cinnamophilin also inhibited the PMA-induced phenomenon. We also found that there are weak inhibitory effects in cinnamophilin on intracellular calcium rising, adhesion molecular-CD11b expression, but no effect on ERK1/2 signaling activation by intracellular calcium analysis, flow cytometry analysis and western blot. In addition, EK8 inhibited the activation of MMPs activation and expression induced by TNF-??, LPS, IL-1?? and TGF-??1 in THP-1 cells by gelatin zymography and western blot, and these inhibitions which not resulted from the effect of cytotoxicity could be proved by MTT assay. In the transcription level, EK8 could suppressed the TNF-??-induced MMP-9 mRNA expression by using RT-PCR. It also inhibit the TNF-??-induced I?羠?? degradation, and furthermore it might affect the JNK signaling pathway. However, the detailed inhibitory mechanisms of cinnamophilin and EK8 are still need to be investigated further. It will be worth studing the related experiments of animal models and clinical trials in the future.