Qing-Luo-Yin Alleviated Experimental Arthritis in Rats by Disrupting Immune Feedback Between Inflammatory T Cells and Monocytes: Key Evidences from Its Effects on Immune Cell Phenotypes.

backgroundQing-Luo-Yin (QLY) is an anti-rheumatic herbal formula. Despite the well-investigated therapeutic efficacy of QLY, its immune regulatory properties are largely unknown. CD4 MATERIALS AND

methodsRA models were induced in male SD rats and were orally treated with QLY. Dynamic metabolic changes in collagen-induced arthritis (CIA) rats were monitored by

resultsThe results indicated that QLY decreased Th17 cells frequency and T cells-released IL-6, IL-17 and GM-CSF in CIA rats, which was attributed to the impaired lymphocyte maturation and altered differentiation. QLY inhibited lactic acid production and inflammatory polarization in the monocytes during the peak period of AIA and CIA. AIA monocytes elicited significant increase in Th17 cells counts, IL-6 and IL-1β secretion in co-cultured splenocytes, which was abrogated by QLY. QLY-containing serum suppressed the phosphorylation of JNK and p65 in AIA lymphocyte-stimulated normal monocytes and consequently inhibited iNOS and IL-1β expression as well as IL-6 and IL-1β production. Matrine, sinomenine and sophocarpine were identified as major bioactive compounds in QLY. These identified compounds effectively inhibited the development of inflammatory T cells using concentrations detected in QLY-treated rats. At higher concentrations (20-fold increase), the chemical stimuli significantly suppressed the production of IL-1β in AIA monocytes by inhibiting JNK and p65 pathways.

conclusionBy targeting inflammatory T cells and monocytes as well as disrupting their interplay, QLY improved immune environment in RA models especially during the active stages of disease.