Anti-inflammatory effect of a fraction from leaves of Pyrus pyrifolia Nakai on LPS-induced THP-1 cells

다국어 초록 (Multilingual Abstract)

Pyrus pyrifolia Nakai (P. pyrifolia) has been used traditionally for diseases such as phlegm, cough, hangover, and fever. The biological activities of leaves of Pyrus pyrifolia were not studied. The purpose of this study was to investigate the anti-inflammatory effect of a fraction from leaves of Pyrus pyrifolia (PP) in lipopolysaccharide (LPS)-induced THP-1 cells. Initially, I examined the Cyto X cell viability assay, which result is that PP was not cytotoxic at the range from 1.25μg/ml to 40μg/ml. Also, the enzyme-linked immunosorbent assay (ELISA) results demonstrate that PP decreased tumor necrosis factor-α (TNF-α), monocyte chemoattractant protein 1 (MCP-1), interleukin-8 (IL-8), and interleukin-6 (IL-6) in protein level. In addition, the result of reverse transcription-polymerase chain reaction (RT-PCR) was that PP reduce TNF-α, IL-8, and MCP-1 in the RNA level. I also confirmed that PP restrains the phosphorylation of p38, c-Jun N-terminal kinase (JNK) and extracellular signal-regulated kinase (ERK). In addition, after stimulation with LPS, it was confirmed that the degradation of IκB-α was suppressed by PP, and the phosphorylation of IκB-α and p65 was suppressed by PP in a concentration-dependent manner. Also, PP increased heme oxygenase 1 (HO-1), which controls the production of inflammatory molecules, by activating nuclear factor erythroid 2-related factor 2 (Nrf2). These results show that PP could be used as an anti-inflammatory drug.

목차 (Table of Contents)

• 1. Abstract 1
• 2. Introduction 3
• 3. Materials and methods 5
• 3.1 Preparation of the plant extract 5
• 3.2 Cell culture 5
• 3.3 Cell viability 6
• 3.4 Enzyme-linked immunosorbent assay (ELISA) 6
• 3.5 Reverse transcription-polymerase chain reaction (RT-PCR) 6
• 3.6 Western blot analysis 7
• 3.7 Statistical analysis 8
• 4. Results 9
• 4.1 Effect of PP on cell viability 9
• 4.2 Effect of PP on the production of pro-inflammatory factors in LPS-stimulated THP-1 cells 11
• 4.3 Effect of PP on the production of pro-inflammatory factors in LPS-stimulated THP-1 cells at the RNA level 13
• 4.4 Effect of PP on the activation of MAPK in LPS-stimulated THP-1 cells 15
• 4.5 Effects of PP on NF-κB transcriptional activity in LPS-stimulated THP-1 cells. 17
• 4.6 Effect of PP on the expression of HO-1 in THP-1 cells. 19
• 5. Discussion 22
• 6. References 24
• Abstract in Korean 27
• Acknowledgement 29