Potential roles of longan flower and seed extracts for anti-cancer

Figure 1 The inhibitory effect of longan seed extract on the growth of cancer cells. The longan seed extract (LSE)-inhibited growth assessed herein consists of cancer cell proliferation by (A) trypan blue assay and (B) colony forming activity. For the cell proliferation assay, 100 000 cancer cells as indicated were seeded in 60-mm sterile plastic dishes and treated with different concentrations of LSE. After incubation at 37 °C for 48 h, cells were detached by treatment with trypsin, and the suspended cells were stained with trypan blue. The viable cells were then counted under a phase contrast microscope. Colony formation activity was assessed by seeding 200 cells into 60-mm dishes then treating these cells with different concentrations of LSE. After incubation for 14 d, the formed colonies that contained more than 50 cells were regarded as one colony, and the numbers of colonies in the dishes were counted. The data represent the average of three independent experiments and are expressed as the mean ± SD.