Acacetin Suppresses IL-1β-Induced Expression of Matrix Metalloproteinases in Chondrocytes and Protects against Osteoarthritis in a Mouse Model by Inhibiting NF-κB Signaling Pathways

Figure 5

Acacetin inhibited IL-1β-induced MMP expression by targeting NF-κB pathways. (a) Chondrocytes were pretreated with acacetin (6.25 μM) for 4 h and then stimulated with IL-1β (10 ng/mL) for the indicated time periods (0, 10, and 30 min). Protein levels of p-IκB kinase (IKK)α/β, IKKα and IKKβ, were evaluated by western blotting. (b) The relative intensity of protein bands. (c) IKKβ-overexpressing chondrocytes were treated for 4 h with or without acacetin (6.25 μM) and then with IL-1β (10 ng/mL) for 30 min. Western blotting was then used to quantify IKKβ, phospho-IKKα/β, and phospho-IκB-α. (d) IKKβ-overexpressing chondrocytes were treated for 4 h with or without acacetin (6.25 μM) and then with IL-1β (10 ng/mL) for 48 h. Western blotting was then used to quantify MMP-1, MMP-3, and MMP-13. (e) Schematic of the proposed mechanism showing that acacetin inhibits MMP expression in chondrocytes by blocking P38 and NF-κB pathways. , , and .

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