Carvacrol, a component of thyme oil, activates PPARα and γ and suppresses COX-2 expression[S]

• Main Authors: Mariko Hotta, Rieko Nakata, Michiko Katsukawa, Kazuyuki Hori, Saori Takahashi, Hiroyasu Inoue
• Format: Article
• Language: English
• Published: Elsevier 2010-01-01
• Series: Journal of Lipid Research
• Subjects: cyclooxygenase; peroxisome proliferator-activated receptor; thymol; essential oil
• Online Access: http://www.sciencedirect.com/science/article/pii/S0022227520313833

Cyclooxygenase-2 (COX-2), the rate-limiting enzyme in prostaglandin biosynthesis, plays a key role in inflammation and circulatory homeostasis. Peroxisome proliferator-activated receptors (PPARs) are ligand-dependent transcription factors belonging to the nuclear receptor superfamily and are involved in the control of COX-2 expression, and vice versa. Here, we show that COX-2 promoter activity was suppressed by essential oils derived from thyme, clove, rose, eucalyptus, fennel, and bergamot in cell-based transfection assays using bovine arterial endothelial cells. Moreover, from thyme oil, we identified carvacrol as a major component of the suppressor of COX-2 expression and an activator of PPARα and γ. PPARγ-dependent suppression of COX-2 promoter activity was observed in response to carvacrol treatment. In human macrophage-like U937 cells, carvacrol suppressed lipopolysaccharide-induced COX-2 mRNA and protein expression, suggesting that carvacrol regulates COX-2 expression through its agonistic effect on PPARγ. These results may be important in understanding the antiinflammatory and antilifestyle-related disease properties of carvacrol.