Icariin inhibits MMP­1, MMP­3 and MMP­13 expression through MAPK pathways in IL­1ß­stimulated SW1353 chondrosarcoma cells.

Osteoarthritis (OA) is the most common type of arthritis and is a leading cause of disability worldwide, resulting in pain, reduced quality of life and socioeconomic burden. Current therapies for OA focus on mitigating the symptoms of advanced disease, but novel therapeutic agents are needed to inhibit the processes leading to OA. The present study aimed to investigate the effects of Icariin on matrix metalloproteinase (MMP)­1, MMP­3 and MMP­13 expression in interleukin (IL)­1ß­stimulated human SW1353 chondrosarcoma cells, and to investigate the possible mechanism underlying the chondroprotective effects of Icariin. In the present study, IL­1ß was applied on SW1353 chondrosarcoma cells to mimic the microenvironment of osteoarthritis. The cells were treated with Icariin and mitogen­activated protein kinase (MAPK) signaling pathway activators or inhibitors. MMP­1, MMP­3, MMP­13, phosphorylated (P)­p38, P­c­Jun N­terminal kinase (JNK) and P­extracellular signal­regulated kinase (ERK) expression was assessed using reverse transcription­quantitative polymerase chain reaction, ELISA and western blot analysis. The results of the present study demonstrated that Icariin inhibited the expression of MMP­1, MMP­3, MMP­13, P­p38, P­ERK and P­JNK. Furthermore, it was revealed that the inhibition of p38 and ERK contributed to the inhibition of MMP­1 and MMP­3 by Icariin, whereas the inhibition of p38 and JNK contributed to the inhibition of MMP­13. The present results suggested that Icariin may have a chondroprotective effect, exerted through the inhibition of MMP­1, MMP­3 and MMP­13 via MAPK pathways. Therefore, Icariin may have potential as a novel therapeutic strategy for the treatment of osteoarthritis.

Xitong Wan attenuates inflammation development through inhibiting the activation of nuclear factor-κB in rats with adjuvant-induced arthritis.

ETHNOPHARMACOLOGICAL RELEVANCE: Xitong Wan (XTW), a traditional Chinese herbs formula, has been used to treat "Bi Zheng" in the clinical practice of traditional Chinese medicine (TCM) for hundreds of years. However, no scientific validation is available on the anti-rheumatic effect of XTW. AIM OF STUDY: This study was carried out to investigate the effects of XTW on joints swelling, joints destruction, production of inflammatory mediators and nuclear factor-κB (NF-κB) activation in rats with adjuvant-induced arthritis (AIA). MATERIALS AND METHODS: AIA was induced by intradermal injection of Complete Freund's adjuvant in the footpad of Wistar rats. Paw volume was measured every 7 days during XTW treatment. Histological score was calculated by hematoxylin and eosin staining. Osteoclast number in articular tissues was counted by tartrate-resistant acid phosphatase staining. Levels of tumor necrosis factor (TNF)-α, interleukin (IL)-1ß and IL-6 in serum were detected by enzyme-linked immunosorbent assay. Levels of NF-κBp65 and inhibitor of NF-κB (IκB)α in synovium were analyzed by Western blot assay. RESULTS: Compared with AIA group rats, XTW significantly decreased the paw volume of AIA rats. Meanwhile, XTW significantly reduced the histological score and osteoclast number in articular tissues of AIA rats. In addition, XTW markedly abated the levels of TNF-α, IL-1ß and IL-6 in serum, as well as enhanced the level of IκBα in synovium of AIA rats. However, XTW did not show significant effect on the level of p65 in synovium of AIA rats. CONCLUSIONS: These results suggest that XTW attenuates the inflammation development through inhibiting the NF-κB-mediated proinflammatory cytokines production in AIA rats. Our study provides the scientific evidence of XTW on treatment of rheumatoid arthritis in the clinical practice of TCM.

Ginsenoside Rb1 inhibits matrix metalloproteinase 13 through down-regulating Notch signaling pathway in osteoarthritis.

Mounting evidence suggests that an excess of matrix metalloproteinase-13 (MMP-13) plays an important role in the breakdown of extracellular matrix in osteoarthritis (OA). Here, the effects of ginsenoside Rb1 (GRb1) on the expression of MMP-13 in IL-1ß-induced SW 1353 chondrosarcoma cells and an experimental rat model of OA induced by anterior cruciate ligament transection (ACLT) were investigated. SW1353 chondrosarcoma cells were pretreated with or without GRb1 and Notch signaling pathway inhibitor, DAPT, then were stimulated with IL-1ß. In rats, experimental OA was induced by ACLT. These rats then received intra-articular injections of vehicle, an inhibitor of γ-secretase, DAPT, and/or GRb1. Expression of MMP-13, collagen type II (CII), Notch1, and jagged 1 (JAG1) were verified by western blotting and immunohistochemistry. In addition, levels of MMP-13 mRNA were detected using quantitative real-time PCR. In histological analyses, treatment with DAPT reduced the number of cartilage lesions present and the expressions of MMP-13, CII, Notch1, and JAG1. In addition, treatment with GRb1 was associated with lower levels of Notch1 and JAG1 in both IL-1ß-induced SW1353 chondrosarcoma cells and in the rat OA model. Furthermore, the suppressive effect of GRb1 on MMP-13 was greater than that exhibited by the signaling pathway inhibitor. In conclusion, GRb1 inhibits MMP-13 through down-regulating Notch signaling pathway in OA.

Chondroprotective effects and multi-target mechanisms of Icariin in IL-1 beta-induced human SW 1353 chondrosarcoma cells and a rat osteoarthritis model.

Cartilage degradation is the most predominant pathological change during osteoarthritis (OA). Furthermore, accumulating evidence suggests that an excess of matrix metalloproteinase-13 (MMP-13) plays a critical role in the breakdown of cartilage. Here, the effects of Icariin on the expression of MMP-13 in IL-1ß-induced SW 1353 chondrosarcoma cells were investigated. In addition, the in vivo effects of Icariin on an experimental rat model of OA induced by anterior cruciate ligament transection (ACLT) was examined. SW1353 chondrosarcoma cells were pretreated with or without Icariin and MAPK and Wnt/ß-catenin signaling pathway inhibitors, then were stimulated with IL-1ß. In rats, experimental OA was induced by ACLT. These rats then received intra-articular injections of vehicle, signaling pathway inhibitors, and/or Icariin. Expression of MMP-13, phosphorylated p38, phosphorylated JNK, and ß-catenin were verified by western blotting. In addition, levels of MMP-13 mRNA were detected using quantitative real-time PCR. In histological analyses, treatment with Icariin reduced the number of cartilage lesions present. In addition, treatment with Icariin was associated with lower levels of phosphorylated p38, phosphorylated JNK, and ß-catenin in both IL-1ß-induced SW1353 chondrosarcoma cells and in the rat OA model. Furthermore, the suppressive effect of Icariin on MMP-13 was greater than that exhibited by other signaling pathway inhibitors. Overall, these data suggest that Icariin has therapeutic potential for the treatment of OA.