Essential oil composition and bioactivity variation in wild-growing populations of Curcuma phaeocaulis Valeton collected from China

The chemical compositions and bioactivities of essential oils from Curcuma. phaeocaulis Valeton rhizomes collected from twelve various locations in China are comparatively investigated. A total of 53 components are identified from essential oils by GC-MS, and the major compounds are 8,9-dehydro-9-formyl-cycloisolongifolene (15.55-46.24%), germacrone (8.88-21.21%), curlone (0.75-20.18%), α-caryophyllene (0.08-11.04%), curzerene (0.63-9.77%) and β-elemene (0.59-5.40%). Most of these essential oils have effective anti-fungus activities (IC50, 153.33-580.09 μg/ml), and they also can inhibit the growth of bacteria (IC50, 485.00-778.33 μg/ml) to some extent. They also exhibit different DPPH radical-scavenging activities (IC50, 2.17-22.36 μg/ml), and the antioxidative activities of some oils are even better than Trolox C. The essential oils reveal good anti-inflammatory activity by markedly down-regulating the expression of COX-2 and TNF-α. The anti-tumor activities of essential oils against LNCaP and B16 cell lines are also studied, and some of them are excellent according to their IC50 values (20.36-245.30 μg/ml). These results indicate some essential oils from wild C. phaeocaulis grown in different areas have outstanding bioactivities, which makes them ideal candidates for natural functional nutrition, pharmaceutical, culinary and cosmetic additives.