Origanum vulgare induces apoptosis in human colon cancer caco2 cells.

Oregano spice is widely used in the Mediterranean diet, which is associated with a low risk for colon cancer. Although the medicinal benefits of oregano, such as the anti-inflammatory and antimicrobial activities, are well known; nonetheless, only few data are available on its effect in cancer prevention, especially concerning the mechanism of action. Here, we investigated the effect of Origanum vulgare ethanolic extracts on redox balance, cell proliferation, and cell death in colon adenocarcinoma Caco2 cells. Oregano extract leads to growth arrest and cell death in a dose- and time-dependent manner. Changes in glutathione content, as well as the increase in its oxidized form, may be involved in oregano-triggered death. Both extrinsic and intrinsic apoptotic pathways appear to be activated by spice extract. Our findings suggest that oregano amounts found in the Mediterranean diet can exert proapoptotic effects, which are selective for cancer cells. Moreover, whole extract, instead of a specific component, can be responsible for the observed cytotoxic effects.