Lycopene had apoptotic effects on all cell lines studied here, and after 96 h, the results showed that dose (5 or 10 μM) did not affect its action. MDA-MB231 cells showed an increase of 300% of the apoptosis rate (96 h) but at a shorter time (48 h) no effect was detected. The cancer-preventive ability of lycopene by inducing apoptosis was already reported in breast, colon and prostate cell lines (22, 27, 42). Malignant T-lymphoblast cells were treated with distinct types of carotenoids to compare their effects on cell behavior and it was concluded that both lycopene and betacarotene positively regulated apoptosis (43). It is important to note that apoptotic effects of lycopene are limited to some types of cancer. For instance, lymphocytic leukemia cell line (EHEB) was indifferent to treatment with lycopene in vitro (40). Moreover, gastric cancer cells presented increased apoptosis after treatment with beta-carotene at supra-physiological concentration (100 μM), modulating the expression of p53 (proapoptotic protein) and B-cell lymphoma-2 (Bcl-2 antiapoptotic protein) (44). Based on these observations, a study with breast cancer cells (MCF-7) confirmed that beta-carotene was able to change the expression of 21 genes related to cell apoptosis (45). As well as lycopene, we observed that beta-carotene acts on all cell lines studied here by increasing apoptosis, but under longer incubation (96 h). These data suggest that lycopene and beta-carotene represent potential anticancer compounds depending on the type of tumor, time and frequency of treatment or consumption, concentration and bioavailability during conventional cancer therapies.