In vivo anti-tumor effect of hirsutanol A on human colon cancer cells SW620 xenografts. Cells were injected subcutaneously in BALB/C nude mice. After 6 days of implantment, BALB/C nude mice were treated with 5% DMSO, NS, hirsutanol A (10 mg/kg) or HPTC (4 mg/kg) for four weeks. Tumor sizes were measured twice weekly until the termination of the experiment (A). Mice were sacrificed on day 21.