Toxicity evaluation of pecan nutshell bioactives against CHO-K1 and MDA-MB 231 cell lines: cytotoxicity, cell cycle arrest and apoptosis

GASSER, FB; RIBAS, LE; RENNA, MS; MARELLI, B; ORTEGA, HH; HEIN, GJ; BARAVALLE, ME

Santa Fe

Congreso; IX SLATCC 2022 Simposio Latinoamericano de Tecnología de Cultivos Celulares; 2022

Centro Biotecnológico del Litoral

The pecan nutshells contain high amounts of phenolic compounds which are believed to be responsible for some bioactive properties such as antioxidant and antitumoral activities. We studied the cytoxicity activity against breast cancer and normal cell lines. After aqueous extraction of bioactives from pecan nutshells, the cytotoxic activity after exposure for 48 h on CHO-K1 (hamster ovary cells) and MDA-MB 231 (human breast cancer cells) was examined through the MTT assay. The IC50 and the selective index (SI) with respect to the normal cells were determined. Cell cycle arrest and induction of cell death were also analyzed by using Propidium Iodide and FITC-Annexin V kit and flow cytometry. Hydrogen peroxide and doxorubicin were used as cytotoxicity positive controls. A dose-dependent decreasing cell viability curve was obtained and the IC50 was 63.13mg/L and 26.47mg/L for the CHO-K1 and MDA-MB 231 cell lines, respectively, with a SI>1 (SI= 2.4) indicating less cytotoxic activity in non-cancerous cells. The main cytotoxicity mechanism of the bioactives (IC50) was the induction of apoptosis (33.4% for CHO-K1 and 54.7% for MDA-MB 231), being lower than the % obtained for doxorubicin (58.1% for CHO-K1 and 96.0% for MDA-MB) (p<0.05). Treatment with bioactives (IC50) resulted in cell cycle arrest at the G0/G1 and G2/M phase for CHO-K1 and MDA-MB 231 cells, respectively. Besides, treatment with doxorubicin (IC50) resulted in cell cycle arrest at the G2/M phase for both cell lines. These bioactives could be relevant as a complementary biotherapeutic to cancer treatments contributing to overall health.