Phytochemical profiles and bioactivities of essential oils extracted from seven Curcuma herbs

The phytochemical profiles, antioxidant, antimicrobial, anti-inflammatory and anticancer capacities of essential oils extracted from seven Curcuma herbs collected in China were investigated. A total of 71 compounds have been identified by means of gas chromatography-mass spectrometer (GC–MS), and the major components are 8,9-dehydro-9-formyl-cycloisolongifolene (10.68 ∼ 52.19%), curdione (0.57 ∼ 50.59%), germacrone (4.54 ∼ 28.05%), zerumbone (1.08 ∼ 15.45%), ar-turmerone (1.64 ∼ 13.80%) and β-elemenone (0.72 ∼ 10.69%). In addition, DPPH free radical-scavenging assay demonstrates the seven essential oils have different antioxidative activities (IC₅₀, 4.52 ∼ 22.32 μg/ml), but most of them are superior to Trolox (IC₅₀, 9.15 μg/ml). These essential oils also exhibit excellent but different inhibitory effects on gram-negative, gram-positive bacteria and fungus. According to IC₅₀ values of MTT assay, they reveal better anticarcinogenic actions against LNCaP cells (1.14 ∼ 18.40 μg/ml) than HepG2 cells (153.06 ∼ 198.18 μg/ml). Besides, the anti-inflammatory activities of some essential oils even overmatch ibuprofen via markedly down-regulating expression of cytokines including COX-2, TNF-α, NF-kB, IKK, Akt and PKC. It is concluded that essential oils of Curcuma herbs with versatile pharmacological activities might be a potential primer to develop new additives for food, cosmetics and pharmaceuticals.