Antiaging effect of Curcuma longa L. essential oil on ultraviolet-irradiated skin

Objective: Essential oil derived from the rhizome of Curcumin longa (CL-EO) has marked anti-inflammatory, antioxidant, antimicrobial, anticancer, and antiviral activities. However, its effect on photodamaged skin has not yet been evaluated. In this study, the anti-skin photoaging activity of CL-EO was determined by performing an ultraviolet B (UVB)-induced skin aging assay. Methods: CL-EO was extracted by hydrodistillation and characterized using gas chromatography-mass spectrometry. The anti-skin aging effect was determined by topically applying 150 mu l of CL-EO diluted to 1, 5, and 10% with ethanol to the dorsal area of UVB-irradiated nude mice every day except on Sunday for 8 weeks. Histological and immunohistochemical analyses were performed. Results: In total, 56 compounds, which accounted for 94.36% of the contents of CL-EO, were detected. The major compounds in CL-EO were ar-turmerone (36.04%), curlone (8.78%), beta-turmerone (7.05%), 8,9-dehydro-9-formyl-cycloisolongifolene (5.69%), beta-sesquiphellandrene (5.39%), germacrone (4.51%), ar-curcumene (2.19%), alpha-himachalene (2.14%), and ledane (2.13%). Hematoxylin and eosin staining of tissue sections revealed that CL-EO decreased epidermal skin thickness. Immunohistochemistry showed that CL-EO inhibited interleukin-1 beta and tumor necrosis factor-alpha expression. Conclusions: Thus, CL-EO can reduce cutaneous photoaging in a UVB-irradiated nude mouse model. Therefore, CL-EO could be used in the formulation of skin care and functional cosmetic products.