The cytotoxic effect of α-tomatine in MCF-7 human adenocarcinoma breast cancer cells depends on its interaction with cholesterol in incubation media and does not involve apoptosis induction

In recent years, -tomatine has been studied for its anticancer activity. In the present study, we focused on the cytotoxic effect of -tomatine in the MCF-7 human breast adenocarcinoma cell line, its mechanism of action, biotransformation and stability in the culture medium. We observed an inhibition of cell proliferation and viability at concentrations of 6 and 9 M but then a recovery of cells occurred. The recovery was not caused by the biotransformation of -tomatine in MCF-7 cells, but by a substantial decrease in the concentration of -tomatine in the culture medium due to its binding with cholesterol. Regarding the mechanism of action of -tomatine, we observed no DNA damage, no changes in the levels of the proteins p53 and p21(WAF1/Cip1), and no apoptosis (neither activated caspase-8 and -9, nor sub-G1 peak, or morphological signs). We found a loss of ATP in -tomatine-treated cells. These results support the conclusion that -tomatine does not induce apoptosis in the MCF-7 cell line.