KEFIRAN in vitro biological activity on enterocytes and mesodermal origin cell lines: Focus on adenocarcinoma cells HT29

Abstract

Kefiran, the exopolysaccharide found in the fermented milk named “kefir” has been receiving attention over the last years due to its interesting biological and functional properties. It is a non-digestible branched glucogalactan with a molecular weight higher than 1 10⁶ Da. Kefiran was isolated from kefir grains and its biological activity was assessed on different cell lines. Proliferation (trypan blue exclusion assay), mitochondrial activity (MTT assay), viability (Alive-Vulnerable-Dead model, AVD) and cell death were studied. It was found that proliferation was not inhibited in mesodermal cell line MC3 (osteoblast cell line) or in not-invasive colonocytes (Caco-2/TC7 cell line); on the contrary, the high invasive HT29 cell line and the UMR106 osteosarcoma cell line were sensitive to kefiran 0.5 mg/mL, and a significant diminishment on cell proliferation was found by trypan blue dye exclusion assay. Kefiran maintained mitochondrial activity while increased cell death processes in a dose-dependent way in HT29 cell line. When viability was assessed by AVD model, it was found that kefiran increased vulnerability status of neoplasic cell line HT29. In summary, in the present work, we shown that kefiran has a different effect on tumor and non-tumor cell lines. Our results contribute to the understanding of kefiran effect on the empirical antitumoral effect attributed to kefir consumption.