For maintaining in the exponential growth phase, the cells were passaged at 70%-80% confluence once a week by trypsin-EDTA (Gibco, USA) (14). EEP were dissolved in DMSO as solvent and were prepared as 100 mg/ml stock solution and were kept at 100 ml volumes at -20°C. Different concentrations of EEP were prepared with DMEM containing FBS 10% just prior
to AGS cells treatment.