Aim: To determine the effects of glycyrrhetinic acid (GA), methotrexate(MTX) and GA+MTX on the expressions of tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) in fibroblast-like synovial (FLS) cells from collagen induced arthritis (CIA) rats.
Methods: CIA-FLS cells were isolated and purified from the synovium of CIA rats by tissue block culture method, and then treated with MTX, GA, GA+MTX or nothing (control group), respectively. Each group was cultured for 3 different time periods (1, 3, 5 d). Real-time qPCR was used to detect the expressions of TNF-α and IL-1β mRNA in CIA-FLS cells and ELISA to determine the levels of TNF-α and IL-1β in the supernatant.
Results: Day 1: No significant down-regulation of TNF-α and IL-1β mRNA was identified in intervention groups compared with the control group (P>0.05); Day 3: Intervention groups significantly down-regulated TNF-α and IL-1β mRNA (P<0.05 vs control), but without intergroup difference(P>0.05); Day 5: the three intervention groups all suppressed the expressions of TNF-α and IL-1β mRNA(P<0.05 vs control), with GA+MTX>MTX>GA in inhibiting effect (P<0.05). All intervention groups were found to inhibit the expressions of TNF-α and IL-1β in a time-dependent manner (P<0.05). Similar outcomes were observed in the change of the levels of TNF-α and IL-1β in cell culture supernatant by ELISA.
Conclusion: GA, MTX, GA+MTX suppress the expression of TNF-α and IL-1β in CIA-FLS cells in a time-dependent manner, and the suppressing effect is GA+MTX>MTX>GA.