To investigate the anti-arthritic activity of the water extract of Rhizoma Arisaematis
using a collagen II -induced arthritis (CIA) rat model.
CIA was induced in male Sprague-Dawley rats by intradermal injection of bovine collagen II
in Complete Freund’s Adjuvant. The rats were treated with daily oral doses of WERA (100, 200, and
400 mg/kg) for 21 consecutive days. Methotrexate (MTX, 3 mg/kg), used as a positive control, was
administered orally 2 times/week for 3 weeks. The severity of arthritis was evaluated using indices of
paw swelling, arthritic score, body weight, thymus index, and spleen index. In addition, the serum levels
of IL-1β, IL-6, IL-10, and TNF-α were measured.
All doses of WERA significantly inhibited paw edema (p < 0.01), decreased arthritis scores (p
< 0.01) and spleen index (p < 0.05), and alleviated the weight loss associated with CIA in rats.
Furthermore, TNF-α, IL-1β, and IL-6 serum levels were significantly decreased (p < 0.05) by all doses of
WERA. By contrast, IL-10 serum levels were markedly increased (p < 0.05).
WERA exerts therapeutic effects in CIA in rats by decreasing the serum levels of TNF-α,
IL-1β, IL-6 and IL-10, suggesting WERA may be an effective candidate drug for treating human