Linoleic acid ameliorates inflammation in rheumatoid arthritis rats via regulation of TLR4/NF-κB signaling pathway / 中国药理学通报

ABSTRACT

Aim To explore the effects of linoleic acid on the joint swelling in rats caused by rheumatoid arthritis (RA), and to reveal possible mechanism underlying the inhibitory effect of linoleic acid on TLR4/NF-κB signaling pathway in RA. Methods The RA rat model was constructed and divided into control group, model group, linoleic acid (0. 1 mL) group, linoleic acid (0.2 mL) group, linoleic acid (0.4 mL) group and methotrexate (MTX) group. After the model was successfully established, the corresponding drugs were given by gavage for seven days. The control group and the model group were given normal saline. The changes of rat joint swelling were measured; joint pathological damage was assessed by HE staining; the protein expression levels and the mRNA expression levels of TNF-α, IL-1β, IL-6 and IL-10 were determined by ELISA and qRT -PCR; the protein expression levels of TLR4 and p-p65 were determined by immunohisto-chemistry and Western blot. Results Compared with model group, linoleic acid significantly alleviated the joint swelling of RA rats; linoleic acid significantly inhibited the joint pathological damage, and markedly reduced the protein expression levels and mRNA expression levels of TNF-α, IL-1β, IL-6 and IL-10; linoleic acid inhibited the protein expression levels of TLR4 and p-p65 in the TLR4/NF-κB signaling pathway. Conclusions Linoleic acid inhibits the protein expression levels of TLR4 and p-p65 in the TLR4/NF-κB signaling pathway, thereby inhibiting the expression of inflammatory factors TNF-α, IL-1β, IL-6 and IL-10.