Objective: To observe the effect of warm needle moxibustion (WNM) on knee-joint swelling and expression of sirtuin 1 (SIRT 1, a class Ⅲ histone/protein deacetylase) and nuclear factor κB (NF-κB) in synovial tissue in rats with rheumatoid arthritis (RA).
Methods: Fifty SD rats were randomly divided into five groups:normal control, model, SIRT 1-inhibitor, WNM, and SIRT 1-inhibitor plus WNM (inhibitor+WNM), n=10 rats in each group. The RA model was established by subcutaneous injection of bovine type Ⅱ collagen at the sole, once daily for 21 days. The WNM was applied to bilateral "Zusanli" (ST 36), "Shenshu" (BL 23) and "Xuanzhong" (GB 39) for 15 min, once daily for 21 days, beginning on the 1st day of modeling. For rats of SIRT 1-inhibitor group and inhibitor+WNM group, nicotinamide solution (10 mmol·kg-1·d-1) was injected intraperitoneally on the 1st, 7th, 14th and 21th days of modeling. The swelling volume of the affected knee-joint was measured by water drainage method. The contents of IL-1 β, IL-6 and IL-8 in the serum were measured by radioimmunoassay. The expression of SIRT 1 and NF-κB p 65 proteins in the synovial tissue of knee-joint were detected by immunoblotting.
Results: After modeling, the knee-joint volume, serum IL-1 β, IL-6 and IL-8 contents, and the expression of NF-κB p 65 protein in synovial tissue of knee-joint were considerably increased relevant to the normal control group (P<0.01), while the expression of synovial SIRT 1 protein was significantly down-regulated (P<0.01). Following WNM intervention, the volume of the knee-joint, serum IL-1 β, IL-6 and IL-8 contents and synovial NF-κB p 65 expression were significantly decreased relevant to the model group (P<0.05), and the down-regulated expression of SIRT 1 protein was notably suppressed (P<0.05). No significant difference was found between the WNM and inhibitor+WNM groups in the knee-joint swelling degree (P<0.05). The contents of serum IL-1 β, IL-6 and IL-8, and the expression of synovial NF-κB p 65 protein of the WNM group were significantly lower than those in the inhibitor+WNM group (P<0.05), while the expression level of SIRT 1 protein was evidently higher than that in the inhibitor+WNM group (P<0.05), suggesting the effects of WNM in down-regulating serum inflammatory cytokines and NF-κB p 65 expression, and in up-regulating SIRT 1 expression after administration of SIRT 1 inhibitor.
Conclusions: Warm needle moxibustion can relieve inflammatory reactions of RA rats, which may be associated to its effect in modulating SIRT 1/NF-κB p 65 signaling in the synovial tissue.