Effect of solvent fractions of kombucha tea on viability and invasiveness of cancer cells—Characterization of dimethyl 2-(2-hydroxy-2-methoxypropylidine) malonate and vitexin

In the present study, cytotoxic and anti-invasive properties of solvent fractions of kombucha tea were studied. Kombucha tea was fractionated with chloroform, ethyl acetate and butanol. Three solvent extracts and the final aqueous phase were concentrated and used for anti-cancer study at 25, 50, 75 and 100 µg/mL concentrations. Results revealed that ethyl acetate fraction at a concentration of 100 µg/mL caused cytotoxic effect on 786-O and U2OS cells; reduced the activities of matrix metalloproteinase-2 (MMP-2) and -9 in 786-O cells and MMP-2 activity in A549 cells; and significantly reduced the cell invasion and cell motility in A549, U2OS and 786-O cells. Thus, ethyl acetate fraction was further purified by chromatographic studies and presence of dimethyl 2-(2-hydroxy-2-methoxypropylidene) malonate and vitexin were confirmed through IR, NMR and mass spectroscopic studies, which might be responsible for the observed anticancer property of kombucha tea.