Anti-proliferative activity of aqueous Yerba Mate (Ilex Paraguariensis) extracts and its bioactive compounds on different adenocarcinoma cell lines

Abstract

Yerba Mate (Ilex Paraguariensis) is a naturally growing plant that is consumed as a tea mainly in South American countries due to its nutritional and healing properties. Its health benefits are attributed to some active molecules that were found to exhibit various biological activities. In the context of cancer, mate tea has not been examined extensively in contrast to other herbal teas. Previous studies highlighted the anti-proliferative effect of methanolic mate extracts on different human cancer cell lines. In this study, we aimed to explore the activity of aqueous mate extract on three distinct human adenocarcinoma cell lines (CaCo-2, HT-29 and HCT116) and one human immortalized epithelial cell line (NCM460). Trypan blue assay showed a gradual decrease in viability of all assessed cell lines with increasing mate concentration at 24h and 48h that was significant mainly at the highest tested mate concentration of 4.5 mg/ml. WST-1 assay revealed that mate extract displayed an anti-proliferative effect on all four cell lines with Caco-2 and HCT-116 showing the strongest effects with a half maximal inhibitory concentration (IC50) of 0.220, 0.138, and 0.24 mg/mL for CaCo-2 cells and 0.295, 0.183, and 0.181 mg/mL for HCT-116 cells at 24, 48, and 72 h, respectively. AnnexinV/Propidium Iodide staining after treatment with 2.3 mg/ml of Yerba Mate extract showed a significant decrease in the viability of CaCo-2 cells from 81% to 26% at 24h and from 81% to 31% at 48h and a significant increase in the percentage of total apoptotic cells from 10% to 44% at 24h and from 12% to 30% at 48h. Cell cycle analysis by flow cytometry demonstrated an increase in the percentage of cells in the SubG0 phase (43.47%) at 2.3 mg/ml of aqueous YME as compared to the untreated (21.05%). Different experiments are currently undergoing to identify the underlying molecular mechanisms of aqueous YME in the colon. In conclusion, Yerba Mate could possibly be targeted for future drug development research.