Abstract:In this study, anti-aging effects of green tea crude water extract were studied using human epidermal keratinocyte as model which induced by ultraviolet B (UVB). The green tea extract of 0~20 μg/mL was added to DMEM cell culture medium, then cells were induced by radiation of 60 mJ/cm2 UVB. The anti-aging effects were studied by cellular morphology, apoptosis level, cell viability, intracellular antioxidant enzyme activity, intracellular active oxygen cluster (ROS) content, malonaldehyde(MDA)content, cell mitochondrial membrane potential and Na+,K+-ATP enzyme activities. The results showed that the crude extract of green tea could obviously improve cell volume, cell shape, and nuclear volume of induced cells. Apoptosis of cells was inhibited, and the survival rate was increased by (30.52±8.69)%. The activity of antioxidant enzyme in cells was obviously improved. ROS content was decreased by 17.16%. The content of MDA was reduced by (50.69±6.81)%. The average light density of red green fluorescence in JC-1 dyeing was increased by 13.75%. Besides, the activity of Na+,K+-ATP enzyme was increased by (103.95±3.64)%. The experimental results show that green tea extracts have anti-UVB induced aging effect on human epidermal cell, and this study may provide scientific basis to develop anti-aging products of green tea.