title: Caesalpinia sappan extract inhibits IL1β-mediated overexpression of matrix metalloproteinases in human chondrocytes.
abstract: Exacerbated production of matrix metalloproteinases (MMPs) is a key event in the progression of osteoarthritis (OA) and represents a promising target for the management of OA with nutraceuticals. In this study, we sought to determine the MMP-inhibitory activity of an ethanolic Caesalpinia sappan extract (CSE) in human OA chondrocytes. Thus, human articular chondrocytes isolated from OA cartilage and SW1353 chondrocytes were stimulated with Interleukin-1beta (IL1β), without or with pretreatment with CSE. Following viability assays, the production of MMP-2 and MMP-13 was assessed using ELISA, whereas mRNA levels of MMP-1, MMP-2, MMP-3, MMP-7, MMP-8, MMP-9, MMP-13 and TIMP-1, TIMP-2, TIMP-3 were quantified using RT-qPCR assays. Chondrocytes were co-transfected with a MMP-13 luciferase reporter construct and NF-kB p50 and p65 expression vectors in the presence or absence of CSE. In addition, the direct effect of CSE on the proteolytic activities of MMP-2 was evaluated using gelatin zymography. We found that CSE significantly suppressed IL1β-mediated upregulation of MMP-13 mRNA and protein levels via abrogation of the NF-kB(p65/p50)-driven MMP-13 promoter activation. We further observed that the levels of IL1β-induced MMP-1, MMP-3, MMP-7, and MMP-9 mRNA, but not TIMP mRNA levels, were down-regulated in chondrocytes in response to CSE. Zymographic results suggested that CSE did not directly interfere with the proteolytic activity of MMP-2. In summary, this study provides evidence for the MMP-inhibitory potential of CSE or CSE-derived compounds in human OA chondrocytes. The data indicate that the mechanism of this inhibition might, at least in part, involve targeting of NF-kB-mediated promoter activation.
authors.affiliation: Department of Orthopaedics, Medical University Vienna, Waehringer Guertel 18-20, 1090, Vienna, Austria, stefan.toegel@meduniwien.ac.at.
authors.forename: Stefan
authors.initials: S
authors.lastname: Toegel
authors.forename: Shengqian Q
authors.initials: SQ
authors.lastname: Wu
authors.forename: Miguel
authors.initials: M
authors.lastname: Otero
authors.forename: Mary B
authors.initials: MB
authors.lastname: Goldring
authors.forename: Pimporn
authors.initials: P
authors.lastname: Leelapornpisid
authors.forename: Catharina
authors.initials: C
authors.lastname: Chiari
authors.forename: Alexander
authors.initials: A
authors.lastname: Kolb
authors.forename: Frank M
authors.initials: FM
authors.lastname: Unger
authors.forename: Reinhard
authors.initials: R
authors.lastname: Windhager
authors.forename: Helmut
authors.initials: H
authors.lastname: Viernstein