Cytotoxicity and in vitro activity of chard (Beta vulgaris L. var cicla) extracts on porcine pancreatic islets

Background: reports from traditional medicine suggest that chard (Beta vulgaris L. var Cicla) can have remarkable effects in diabetes therapy. Objective: to evaluate the cytotoxic activity of chard extracts in cell lines and determine the viability of cultured porcine pancreatic islets added with or without chard extracts. Methods: cytotoxic activity of chard extracts was assessed in non-tumor and tumor cell lines using the MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] technique, and the ability of extracts to maintain porcine pancreatic islets viability and regeneration in vitro was tested. Results: the 50% cytotoxic concentration (CC50) of extracts for non-tumor cell lines was above 1,000 µg/mL, while it was 825 µg/mL, 283 µg/mL, 136 µg/mL and 380 µg/mL, for hexane, ethyl acetate, ethanol and water extracts in the tumor cell line, respectively. The CC50 ratio between cell lines indicates that ethanol extract is 7.5 times more toxic to tumor than non-tumor cell lines. There was an increase in viability of porcine pancreatic islets cultured with aqueous, ethyl acetate, and ethanol extracts compared with standard media (CMRL1066) and Cyclosporine A (CsA) control groups. Furthermore, a greater than one regeneration index of islets cultured with ethanol extract at 1,000 µg/mL and 500 µg/mL concentrations during 15 days was observed, which remained constant and was significantly higher than CsA group. Conclusions: these results suggest that chard metabolites should be researched to develop antitumor therapies and human pancreatic islets recovery in diabetes treatment.