Cytotoxic effect of a tepary bean (Phaseolus acutifolius) lectin on human cancer cell lines

Abstract

Lectins can specifically recognize carbohydrates of cell membranes and some of them exhibit anticancer properties. In a previous work, we identified a cytotoxic lectin from tepary bean with differential antiproliferative effect on normal and transformed fibroblasts. The goal of the present work was to evaluate the effect of a concentrated tepary bean lectin fraction (TBLF) on human cancer cell lines growth. TBLF was obtained by molecular weight exclusion and ion exchange chromatography and it was tested on breast cancer cells (MCF‐7 and ZR‐75), cervix cancer cells (HeLa, SiHa and C33A) and colon cancer cells (CaCo2). All cell lines showed a cytotoxic effect, after 72 h of treatment. Inhibitory (IC50) and lethal (LC50) concentrations were calculated for each cell line. The most sensible cells were colon cancer cells with IC50 of 0.119 and LC50 of 3.0 μg protein/mL. CaCo2 and normal intestinal cells from rat illeon (IEC‐18), included as normal counterpart, were also tested at 24 h, LC50 did not change for CaCo2 but IC50 was of 0.563 μg protein/mL; for IEC‐18, IC50 and LC50 were of 0.993 and 7.95 μg protein/mL, respectively. Our results show that TBLF is able to recognize selectively different types of cancer cells, more over between normal and cancer cells. Current studies are focusing on TBLF mechanism action and on in vivo studies against colon cancer.

Effect of Induced Mechanical Leaf Damage on the Yield and Content of Bioactive Molecules in Leaves and Seeds of Tepary Beans (Phaseolus acutifolius)

“…Specifically, the findings show that the colon cancer cell lines (CaCo 2 ) were the most sensitive, requiring less quantity to reach lethal concentration 50 (LC 50 ) and inhibitory concentration 50 (IC 50 ), followed by breast cancer cell lines (ZR-75 and MCF-7) [4,9]. In another study, a differential effect was observed between CaCo-2 cells and nontransformed ileum cells (IEC-18) [10]. An inhibitory effect on the proliferation of colon cancer cells (SW-480) has also been reported after 48 h of exposure to Tepary bean lectins [11].…”