Antioxidant and Anti-Inflammatory Activities of Essential Oils: A Short Review

Miguel, Maria Graça

The fruit essential oils of Cinnamomum insularimontanum Hayata and citral were revealed to possess significant inhibitory effects on NO production in LPS-stimulated RAW 264.7 cells. Citral exhibited an inhibitory activity in LPS-induced iNOS protein expression, not found for COX-2. The authors studied the effect of citral on NF-κB pathway for enlightening the mechanism of the citralmediated inhibition of iNOS transcription. The authors concluded that citral could prevent the degradation of IκBα in LPS-induced inflammation and reduce the p50 NF-κB levels in nuclear fractions [121] . In another study, it was reported that in human macrophage-like U937 cells, citral suppressed both LPS-induced COX-2 mRNA and protein expression, dose-dependently. Moreover, citral induced the mRNA expression of the PPARα and the PPARγ, suggesting that citral activates PPARα andγ, and regulates COX-2 expression [147] . A same behaviour was observed for carvacrol.