title: Effect of Phellodendron amurense in protecting human osteoarthritic cartilage and chondrocytes.
abstract: BACKGROUND
  Traditional medicine has been widely using Phellodendron amurense Rupr. (Rutaceae) to treat various inflammatory diseases including arthritis.
  
  
  OBJECTIVE
  This study investigated the effects of Phellodendron amurense in protecting cartilage, including regulating the levels of aggrecanases, matrix metalloproteinases (MMPs)/tissue inhibitor of metalloproteinase (TIMP), proinflammatory cytokines and signaling of the mitogen activated protein kinase (MAPK) pathway in human osteoarticular cartilage and chondrocytes.
  
  
  METHODS
  Explants from human osteoarthritis cartilage were cultured alone or in IL-1α for 7 days with or without Phellodendron amurense ethanol extract or celecoxib (40, 100, 200μg/ml). The effect of Phellodendron amurense on matrix degradation induced by IL-1α in human articular cartilage was assessed by staining, and the quantities of sulfated glycosaminoglycan (GAG) and type II collagen were calculated from the culture media. The levels of aggrecanases, MMPs, TIMP, and PGE(2) in the culture media were investigated using an enzyme-linked immunosorbent assay (ELISA). In addition, reverse transcription polymerase chain reaction (RT-PCR) evaluated the mRNA expression of aggrecanases, MMPs and TIMP. Furthermore, Western blot analysis was performed to identify the roles that Phellodendron amurense played in the ERK, JNK and p38 signaling pathways.
  
  
  RESULTS
  Phellodendron amurense showed no evident cytotoxicity on human articular cartilage. Phellodendron amurense significantly inhibited the IL-1α-induced degradation of GAG and type II collagen from human osteoarticular cartilage in a concentration-dependent manner. Celecoxib did not significantly inhibit IL-1α-induced release of GAG and only slightly reduced type II collagen. Phellodendron amurense also dose-dependently decreased the levels of aggrecanase-1 and -2, MMP-1, -3, and -13, whereas it increased TIMP-1 expression in human osteoarticular cartilage. Celecoxib only decreased MMP-1 and MMP-13 levels in human osteoarticular cartilage. In addition, Phellodendron amurense reduced the phosphorylation of extracellular signal regulated kinase (ERK)1/2, Jun NH2-terminal kinase (JNK) and activated phospho-p38 MAPK in a dose-dependent manner in human osteoarthritic chondrocytes.
  
  
  CONCLUSIONS
  Phellodendron amurense inhibited osteoarticular cartilage and chondrocyte destruction by inhibiting proteoglycan release and type II collagen degradation, down-regulating aggrecanases, MMP activities and phospho-ERK1/2, JNK and p38 MAP kinase signaling, and up-regulating TIMP-1 activity. Therefore, our results suggest that Phellodendron amurense is a potential therapeutic agent to protect cartilage against OA progression.
authors.affiliation: Department of Acupuncture & Moxibustion, College of Oriental Medicine, Kyung Hee University, 1 Hoegi-dong, Dongdaemun-gu, Seoul 130-702, Republic of Korea. jhkim714v@naver.com
authors.forename: Joo-Hee
authors.initials: JH
authors.lastname: Kim
authors.forename: Jeong-Eun
authors.initials: JE
authors.lastname: Huh
authors.forename: Yong-Hyeon
authors.initials: YH
authors.lastname: Baek
authors.forename: Jae-Dong
authors.initials: JD
authors.lastname: Lee
authors.forename: Do-Young
authors.initials: DY
authors.lastname: Choi
authors.forename: Dong-Suk
authors.initials: DS
authors.lastname: Park
mesh_terms: D051722:ADAM Proteins / Q000235:genetics / Q000378:metabolism; D000071121:ADAMTS4 Protein; D002358:Cartilage, Articular / Q000187:drug effects* / Q000378:metabolism; D000068579:Celecoxib; D002478:Cells, Cultured; D019902:Chondrocytes / Q000187:drug effects* / Q000378:metabolism; D024043:Collagen Type II / Q000187:drug effects* / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D010450:Endopeptidases / Q000378:metabolism; D006025:Glycosaminoglycans / Q000378:metabolism*; D006801:Humans; D053582:Interleukin-1alpha; D020782:Matrix Metalloproteinases / Q000235:genetics / Q000378:metabolism; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D010003:Osteoarthritis / Q000188:drug therapy* / Q000378:metabolism; D032102:Phellodendron; D010766:Phosphorylation; D008517:Phytotherapy; D024301:Plant Bark; D010936:Plant Extracts / Q000494:pharmacology* / Q000627:therapeutic use; D018547:Plant Stems; D011348:Procollagen N-Endopeptidase / Q000235:genetics / Q000378:metabolism; D011720:Pyrazoles / Q000494:pharmacology; D012333:RNA, Messenger / Q000378:metabolism; D013449:Sulfonamides / Q000494:pharmacology; D019715:Tissue Inhibitor of Metalloproteinase-1 / Q000235:genetics / Q000378:metabolism
chemical_list: D024043:Collagen Type II; D006025:Glycosaminoglycans; D053582:Interleukin-1alpha; D010936:Plant Extracts; D011720:Pyrazoles; D012333:RNA, Messenger; D013449:Sulfonamides; D019715:Tissue Inhibitor of Metalloproteinase-1; C020341:glucosaminoglycans; D020928:Mitogen-Activated Protein Kinases; D010450:Endopeptidases; D051722:ADAM Proteins; D020782:Matrix Metalloproteinases; D011348:Procollagen N-Endopeptidase; D000071121:ADAMTS4 Protein; C083641:aggrecanase; D000068579:Celecoxib