THE INHIBITORY EFFECTS OF PURE BLACK TEA THEAFLAVINS ON THE GROWTH OF FOUR SELECTED HUMAN CANCER CELLS

Abstract

The growth inhibition and cytotoxic effects of theaflavins mixture and pure theaflavins [theaflavin, theaflavins-3-gallate, theaflavins-3′-gallate and theaflavin-3, 3′-digallate] from black tea on human liver cancer HepG2 cells, gastric cancer SGC-7901 cells, lung cancer A549 cells and acute promyelocytic leukemia K562 cells were investigated. The four major theaflavins were obtained from enzymatically oxidized catechins mixture using preparative high-performance liquid chromatography (HPLC). The purity and the structures of the isolated compounds were confirmed by 1H nuclear magnetic resonance, Liquid chromatography-mass spectrometry (LC/MS), Fourier-transform infrared, HPLC with diode array detection and thin-layer chromatography analyses. Theaflavin monomers and mixture exhibited strong inhibitory effects on SGC-7901 and A549 cells. The obtained TF2A exhibited high inhibition activity against the growth of all four cancer cells examined. It is concluded that individual theaflavins have differential inhibitory activity in cancer cell lines and that TF2A have promising activity to be considered in anticancer treatment research as a drug or a template for drug synthesis. PRACTICAL APPLICATIONS Theaflavins have received much attention because of their potential benefits for human health. In this study, we used a modified method for the preparation and isolation of theaflavins and examined the cytotoxic activity of the individual theaflavins against human liver cancer (HepG2) cells, gastric cancer (SGC-7901) cells, lung cancer (A549) cells and acute promyelocytic leukemia (K562) cells. Our results demonstrates that individual theaflavins have differential inhibitory activity in cancer cell lines and has the potential to be used individually for functional food applications and for therapy targeting specific cancer treatments. The most active theaflavin (TF2A) is a promising compound that can be used as a drug or a template for drug synthesis for anticancer research.