Analysis of the pentane fraction obtained from Daucus carota oil extract and its activity against colon cancer cell lines

Phytotherapy has been widely used throughout the years for the treatment of a variety of diseases such as colon and colorectal cancers. Recent studies in our laboratories have shown that Daucus carota (Linnaeus) ssp. carota possesses potential anti-tumor activity. Oil extract (1:1 methanol/acetone) of Daucus carota grown in Lebanon was subjected to a chromatographic separation using a pentane based mobile phase to yield four fractions. GCMS analysis of the first fraction, F1, reveals 11 components present in excess of 1%, such as α-longipinene (2.97%), humulene (13.2%), (10S,11S)-himachala-3(12)-4-diene (2.56%), caryophyllene (7.41%), β-selinene (32.6%), β-himachalene (3.96%) and caryophyllene oxide (2.33%). The anticancer effect of the F1 fraction was tested against colon cancer cell lines, HT-29 and Caco-2, and the results demonstrated that the F1 fraction had an anti-proliferative effect against both cell lines. The F1 fraction also exhibited dose dependent cytotoxicity against all tested cell lines with IC₅₀ values of 25µg/mL for HT-29 cells and 15µg/mL for Caco-2 cells. A comparitive study of Daucus carota from various geographic locations including Lebanon and Europe revelead significant differences regarding the major components present in the methanol/acetone oil extract. In conclusion, the composition of the Daucus carota oil extract is dependant on geographical location and that the F1 fraction of the oil extract obtained from Daucus carota grown in Lebanon posseses anticancer activity.