Therapeutic effects of Chinese medicine Di-Long (Pheretima vulgaris) on rheumatoid arthritis through inhibiting NF-κB activation and regulating Th1/Th2 balance

Chinese medicine Di-Long, the dried body of Pheretima vulgaris (Chen) has been used for the treatment of joint inflammation, arthralgia and numbness of limbs for many years. This study was to investigate the anti-rheumatoid arthritis (RA) effects of Di-Long and to explore its possible mechanisms. The identification and quantification of representative components in Di-Long extracts (DL) were carried out by HPLC analysis. The anti-RA effects and mechanisms of DL were studied in CIA mice, RAW 264.7 macrophages and spleen T lymphocytes. The Th1/Th2 cell ratio in CIA mice spleens were determined by Flow cytometry. The cytokine levels were determined by ELISA method. The expressions of p-NF-kappa B p65 in ankle joints of CIA mice were detected by Immunohistochemistry analysis. The phosphorylation of NF-kappa B signaling pathway in RAW 264.7 macrophages and expressions of T-bet and GATA-3 in CIA mice spleens were determined by Western blots. The treatment with DL significantly decreased the paw thickness, arthritis scores and inflammatory cells infiltration in CIA mice. The TNF-alpha, IL-6 concentrations in both mice serum and macrophages secretion were markedly reduced with the treatment of DL, as well as the phosphorylation of NF-kappa B pathway. DL inhibited the expressions of T-bet and GATA-3 and decreased Th1/Th2 cells ratio in CIA mice spleens. DL reduced IFN-gamma, IL-2 levels in mice serum and spleen T lymphocytes, and increased IL-4 levels in CIA mice serum. Chinese medicine Di-Long have significant anti-RA effects. The mechanisms might be inhibiting the activation of NF-kappa B signaling pathway and regulating the balance of Th1/Th2 cells.