Cytotoxic effect of wild carrot oil fractions on human epidermal keratinocytes

Wild carrot has been used in traditional medicine in Lebanon to treat several diseases. Recently, Daucus carota oil extract and its fractions, F1 (pentane; 100%), F2 (pentane-diethyl ether; 50:50), F3 (diethyl ether; 100%) and F4 (chloroform-methanol; 93:7), were shown to possess anticancer and antioxidant activities [1,2]. The present study aims to complete spectrum of the anticancer activity of the 4 fractions against three types of human epidermal keratinocytes (HaCaT cells) cell lines HaCaT-II4 (non-invasive), HaCatT-A5 (invasive) and HaCaT (immortalized). Cells were treated with 10, 25, 50 and 100 µg/mL of the fractions for 48h and cell survival was determined using WST-1 assay. The 4 fractions exhibited a dose-dependent inhibition of cell viability, with F1 and F2 being more potent (p < 0.05) than F3 and F4. The immortalized HaCat cell line was more resistant to cytotoxicity compared with the two malignant counterparts (p < 0.05). The IC50 values of F1, F2, F3, and F4 fractions in the immortalized HaCat cells were respectively 34, 37, 50 and 45 µg/mL, which were significantly (p < 0.05) higher than that of HaCat-A5 cells with IC50 values of 26, 32, 38 and 36 µg/mL respectively and of HaCat-II4 cells with IC50 values of 26, 24, 39 and 34 µg/mL. In conclusion, the results show that F1 and F2 are more toxic to invasive and non-invasive HaCaT than the immortalized cells. Further studies are needed to isolate and characterize the biologically active compounds in F1 and F2.