Cytotoxic activity of mammea type coumarins from Mammea siamensis flowers

Abstract

Mammea siamensis (Miq.) T. Anderson (local name: sarapi) is a Thai medicinal plant in the family Clusiaceae and used in indigenous medicine as a heart tonic. The n-hexane fraction from M. siamensis flowers CH2Cl2-CH3OH (1:1) crude extract yielded coumarins of the mammea type: mammea A/AA, mammea A/AA cyclo D, mammea A/AB cyclo D, mammea A/AC cyclo D, deacetylmammea E/BA, and deacetylmammea E/BB. The isolated compounds were examined in an in-vitro XTT assay against the human MDA-MB-231 (breast adenocarcinoma), U-251 (central nervous system), HCT-116 (colon cancer), as well as the CCRF-CEM (leukemia) cancer cell lines. Only mammea A/AA and the mixture of deacetylmammea E/BA and deacetylmammea E/BB were found to possess significant cytotoxic activities, at 10µg/mL in CCRF-CEM with values of 78.1±0.8% and 95.9±1.1%; in MDA-MB-231 with values of 58.9±0.8% and 82.4±0.9%; in U-251 with values of 27.7±3.2% and 78.8±1.6%; and in HCT-116 with inhibition values of 73.5±4.9% and 97.6±0.6% in the four human cancer cell lines, respectively, comparable to vinblastine at 0.01µg/mL, with values of 44.2±8.5%, 51.5±12.9%, 71.0±2.5%, and 54.8±9.4%, respectively. Mammea A/AA and the mixture of deacetylmammea E/BA and deacetylmammea E/BB showed significant cytotoxic activities against the human MDA-MB-231, U-251, and HCT-116 as well as the CCRF-CEM cancer cell lines with IC50 values of 7.2±1.0, 5.2±1.0; nd, 19.1±1.0; 16.6±1.1, 6.5±1.0; and 20.9±1.4, 4.9±1.0µM, respectively.