Inhibitory effect of the extract of Phellodendron amurense ruprecht root on collagen-induced arthritis in mice / 中国结合医学杂志

ABSTRACT

<p><b>OBJECTIVE</b>To investigate whether the dried root of Phellodendron amurense Ruprecht (Phellodendri cortex; PC) extract improves arthritic symptoms through anti-inflammatory and immune-modulatory effects in collagen-induced arthritis in mice.</p><p><b>METHODS</b>Rheumatoid arthritis (RA) was induced in male DBA/1 mice by immunization with type II collagen (ColII). CIA mice were divided into 5 groups (n=10 per a group) with normal, CIA control, PC extract (50 mg/kg and 100 mg/kg)-treated, and meloxicam (50 mg/kg)-treated as the reference drug. The PC extract or meloxicam were administered orally in CIA mice once a day for 14 days after arthritis induction. Arthritic score, levels of anti-ColII IgGantibody, prostaglandin E(PGE), tumor necrosis factor (TNF)-α, and interleukin (IL)-17 in the sera of CIA mice were measured. Histopathological changes in the ankle joints of CIA mice were also analyzed by staining with hematoxylin and eosin (H and E), safranin-O and immunohistochemistry using anti-TNF-α and anti-IL-17 antibodies.</p><p><b>RESULTS</b>The arthritic score was increased in CIA mice in a time-dependent manner, as were the serum levels of anti-ColII IgGantibody, PGE, TNF-α, and IL-17. However, the oral administration of PC extract at 50 and 100 mg/kg in CIA mice significantly decreased the arthritic scores, and the serum levels of anti-ColII IgG, PGE, TNF-α, and IL-17 compared with those in the CIA group (P<0.05 or P<0.01). Furthermore, histopathological improvement of the joint architecture in CIA mice was observed after administration of PC extract. PC extract also significantly inhibited the expression of TNF-α and IL-17 in the joints of CIA mice by suppressing the expression of their mRNA and proteins.</p><p><b>CONCLUSION</b>PC extract may improve the pathological progression of RA through the inhibition of joint destruction by synovial inflammation and immune-stimulation, therefore, it would be a potential anti-arthritic agent in RA.</p>