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-in...
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.