Effect of extracted malva nut gum on reducing high glucose levels by Caco-2 cells

Mucilage of malva nut seeds has been commercially produced as a functional beverage in many South East Asian countries. The purposes of this research were, first, to analyze chemical compositions of different layers of malva nut seeds. Second objective was to investigate the efficacy and dose response of malva nut gum (MNG) for the reduction of glucose uptake in Caco-2 cells. Third objective was to determine the effect of 30 min pre-incubation of Caco-2 cells with various MNG preparations on the uptake of glucose. Caco-2 cells were incubated in Dulbecco's Modified Eagle's Medium (DMEM) containing (i) different concentrations of glucose (i.e. 5.5, 25 mM), (ii) different sources of glucose (i.e. sucrose, starch), (iii) different types of dietary fiber contained in different preparations of gum extracted from malva nut seeds and guar nuts. The cells were incubated in glucose containing DMEM under two different conditions: simultaneous and 30 min pre-incubation conditions. Scanning electron microscopy showed porous surface of extracted MNG compared to malva nut seed. In 25 mM glucose concentrate containing DMEM, the optimal level of dietary fiber to significantly reduce glucose uptake was 0.25% for malva nut seed, extracted MNG and mixed gum, but 0.5% for guar gum. FT-IR showed additional bands in the mixture of each gum and glucose. The contents of glucose uptake for the cells pre-incubated for 30 min, were 50-85% lower than that of the control. These results demonstrate that MNG is effective in lowering glucose uptake by Caco-2 cells in both low and high carbohydrate concentrations.