Investigation of the effect of phlomisoside F on complete Freund's adjuvant-induced arthritis

Phlomis younghusbandii Mukerjee (Labiatae) has been reported to be effective in the treatment of rheumatoid arthritis (RA). In the present study, the anti‑inflammatory and anti‑arthritic effects of phlomisoside F (PF), isolated from P. younghusbandii Mukerjee (Labiatae), were investigated in male Wistar rats subjected to carrageen‑induced paw edema and complete Freund's adjuvant (CFA)‑induced arthritis. Arthritis scores were evaluated by a 5-point ordinal scale (scores 0-4). Expression levels of TNF-α, IL-1β, IL-6, IL-10, COX-2 and 5-LOX were determined via ELISA and western blot assays. Subsequent to establishing the edema and arthritis models, oral administration of PF (5, 10 and 20 mg/kg) significantly inhibited mean edema rate, compared with the control group in carrageenan‑induced paw edema assay. In addition, administration of PF (5, 10 and 20 mg/kg/day) for 28 days markedly exhibited an anti‑arthritic activity by offsetting the body weight loss, inhibiting the paw edema, reducing the arthritis scores and the indices of thymus and spleen, inhibiting the expression levels of TNF‑α, IL‑1β, IL‑6, COX‑2 and 5‑LOX, and increasing the expression of IL‑10, when compared with the respective control group in CFA‑induced arthritis assay. In conclusion, PF is a valuable anti‑arthritic constituent of P. younghusbandii, and the present study results suggest that this herb may be used in the treatment of RA.