Abstract:Osteoarthritis (arthritis) is biomechanical, biochemical and cellular phenomenon, and is not known as a degenerative disease. Arthritis is one of the common chronic diseases and the most important reason of physical disability in the world. According to its side effect such as peptic ulcers, gastrointestinal bleeding, liver toxicity and renal complications dueofprescribing current treatment contain corticosteroid and nonsteroidal, we decided to evaluate possible effect of anti-inflammatory Esential oil of Fraxinus excelsior (EOFE) on biomarkers involved in disease. EOFE were prepared of genetic resources center. Bovine articular cartilage derived from the metacarpophalangeal joints of 14-18-month-old animals (without any sign of inflammation and bleeding) sent to laboratory in sterile bags at 4ºC. Cells were cultured in appropriate condition and counted by hemocytometer, viability assessed by trypan blue. After LPS treatment, cytokine levels were assayed. Cells cultures again and were kept in 37C, 90% humidity in CO 2 incubator and after RNA extraction, RT-PCR and PCR done. Also by Real-time PCR, gene expression was evaluated. E.E.F.E level cause down regulation of COX-2, IL-1β, TNF-α in LPS-stimulated cells.