Effects of the Medicago scutellata trypsin inhibitor (MsTI) on cisplatin-induced cytotoxicity in human breast and cervical cancer cells.

BACKGROUND

Snail medic (Medicago scutellata L.) seeds exhibit a significantly higher content of a trypsin inhibitor than other Medicago species. This inhibitor belongs to the Bowman-Birk family of serine protease inhibitors (BBI) and exhibits a good sequence homology with the BBI from soybean, while presenting some differences. It has been suggested that BBIs have antitumoral and radio-protective activity.

METHODS

In order to assess whether the inhibitor from Medicago scutellata (MsTI) seeds show similar properties to those of BBI from soybean with respect to potentiation of cisplatin-induced cytotoxicity, we evaluated the effects of MsTI on cisplatin-induced cell killing in MCF7 human breast carcinoma cells and HeLa human cervical carcinoma cells.

RESULTS

The 24-hour treatment of MsTI in the cell culture medium decreased the clonogenic survival of MCF7 and HeLa cells in a dose-dependent manner and enhanced cisplatin-induced cytotoxicity. The presence of MsTI during the entire incubation period reduced the D37 of cisplatin by 40% in both the cell lines.

CONCLUSIONS

MsTI could be an useful agent for the potentiation of cisplatin-mediated cancer treatment.