, vol. 9, issue 11, pp. 488-493, 2015.
Background: Many investigations have been performed on the cytotoxic activity of different Euphorbia species and proved to possess moderate to strong cytotoxic effect on different human cancer cell lines. Objective: Current study aim is to determine the cytotoxic activity of the chloroform fraction derived from Euphorbia cooperi N. E. Br. latex methanolic extract on three human cancer cell lines, namely, breast cancer (MCF7), hepatocellular carcinoma (HepG2), and cervix cancer (HELA) cells in comparison to normal human melanocyte (HFB4) using Sulforhodamine B (SRB) assay. In addition, isolation and identification of the chemical constituents that might be responsible for the cytotoxic effect will be carried out. Results: The chloroform fraction showed potent cytotoxic activity against MCF7 cell line (IC50 = 4.23 ± 0.08 μg/ml), moderate activity against HepG2 (IC50 = 10.8 ± 0.74 μg/ml) and weak activity against HELA (IC50 = 26.6 ± 2.1 μg/ml) compared to standard doxorubicin (IC50 = 3.3 ± 0.1, 4.8 ± 0.14, 4.2 ± 0.3 μg/ml, respectively). The chloroform fraction indicated its possible selectivity against cancer cells rather than normal cells (IC50 = 15.6 ± 1.15 μg/ml on HFB4) compared to doxorubicin (IC50 = 4.0 ± 0.21 μg/ml on HFB4). A triterpene, euphol (1), one steroid, obtusifoliol (2) together with one diterpenoid with tigliane skeleton, 12-deoxyphorbol-13-isobutyrate-16-angelate-20-acetate (3) were isolated for the first time from the chloroform fraction of the latex of the plant under investigation. The structures of the isolated compounds were established on the basis of physical and spectroscopic analysis, including 1D and 2D NMR experiments and by comparison with the literature data. Conclusion: The present study demonstrated that the chloroform fraction of the latex of E. cooperi N. E. Br. showed promising cytotoxic activity especially against breast cancer.
