Anti-arthritic and anti-inflammatory activity of linalool against formaldehyde and complete Freund's adjuvant induced arthritis in rats

Arthritis, characterized by persistent joint inflammation, poses a significant challenge due to its detrimental effects on cartilage function and subchondral bone health. This study investigates the potential pharmacological effects of linalool, a monoterpene alcohol commonly found in essential oils, as a promising treatment for arthritis. In vitro assays, including red blood cell membrane stability and protein denaturation tests, were conducted to preliminarily assess the anti-arthritic potential of linalool. Preclinical evaluations were performed on rats with arthritis induced by formaldehyde and complete Freund's adjuvant, focusing on the therapeutic effects of orally administered linalool over a 28-day period. Linalool treatment resulted in significant improvements in body weight, reduced paw inflammation, and decreased arthritis symptoms. Hematological and biochemical analyses revealed that linalool reduced lipid peroxidation and elevated antioxidant levels in arthritic rats. Reverse transcription-polymerase chain reaction analysis demonstrated a notable downregulation of pro-inflammatory markers such as IL-1β, IRAK, NF-κB, TNF-α, and IL-17, alongside an upregulation of the anti-inflammatory cytokine IL-10, in linalool-treated rats compared to controls. These results suggest that linalool is promising as an alternative therapeutic intervention for inflammatory joint diseases.