tectoridin and Arthritis--Rheumatoid

Tectoridin, isolated from the dry rhizome of iris, is a compound with multiple biological activities. However, its biological roles in rheumatoid arthritis (RA) have still not been clearly elucidated. The aim of this study was to focus on the effects of tectoridin on tumor necrosis factor (TNF)-α-induced human fibroblast‑like synoviocyte rheumatoid arthritis (HFLS‑RA) cells, and its associated mechanisms. After TNF-α stimulation, CCK8 and MTT assays, TUNEL assay and flow cytometry, Western blotting and immunohistochemistry analysis were performed to check the cell proliferation, cell apoptosis and cycle analysis, and the expression of related proteins, respectively. Our results showed that tectoridin significantly hindered cell proliferation, S-to-G2/M phase transition and down-regulated Cyclind 1 and PCNA protein levels. Additionally, tectoridin markedly promoted apoptosis rates of HFSL-RA cells and elevated the expression levels of Cleaved Caspase-3 and Bax, while reduced the expression level of Bcl-2. Moreover, tectoridin reversed TNF-α-induced overexpression of MMPs and factors associated with the TLR4/NLRP3/NF-κB pathway. We conclude that tectoridin ameliorated TNF-α-induced proliferation and inflammation by inhibiting TLR4/NLRP3/NF-κB pathway. It might provide a new insight for the clinical application of RA.

Topics: Apoptosis; Arthritis, Rheumatoid; Cell Proliferation; Cells, Cultured; Humans; Inflammation; Isoflavones; NF-kappa B; NLR Family, Pyrin Domain-Containing 3 Protein; Signal Transduction; Toll-Like Receptor 4; Tumor Necrosis Factor-alpha

Rheumatoid arthritis (RA) is a chronic inflammatory disease characterized by inflammation infiltration of the synovial tissues and the fibroblast-like synoviocytes. Tectoridin is a botanical active ingredient with anti-inflammatory properties. In this study, the anti-arthritic effects of tectoridin and its mechanism of action are examined in TNF-α-induced human fibroblast-like synovial cells (HFLSs cells) and complete Freund's adjuvant (CFA)-stimulated arthritic mice. Arthritis progression was evaluated via bodyweight, hind paw swelling, organ index, and synovial pathology. IL-1β, IL-6 and other pro-inflammatory factors concentrations, and the expression of MAPK pathway proteins in HFLSs cells and arthritic mice were measured using ELISA and western blotting. Results showed that tectoridin significantly decreased the swelling of the paws and joints as well as the increased immune organ index within CFA-induced arthritic mice. Histopathological analysis showed that tectoridin alleviated the lesions of ankle joints and synovial tissues induced by CFA. Secretion of pro-inflammatory cytokines in TNF-α-induced HFLSs cells and CFA-stimulated arthritic mice were also abated by tectoridin. Similarly, the presence of tectoridin significantly inhibited the abnormal phosphorylation levels of ERK, JNK, and p38 in vivo and in vitro. All those results highlighted that tectoridin exhibits anti-arthritis effects by inhibiting MAPK-mediated inflammatory responses.

Topics: Animals; Arthritis, Experimental; Arthritis, Rheumatoid; Cytokines; Edema; Freund's Adjuvant; Humans; Isoflavones; Mice; Tumor Necrosis Factor-alpha