PA inhibits tumor xenograft growth in vivo. (A) Vehicle control and PA (10, 30 and 60 mg/kg) were administered for 4 weeks by intraperitoneal injection. (B) Tumor volume and (C) weight of the mice were monitored, respectively. Scale bar, mm. Data in the graphs represent the mean ± standard deviation (n=6). *P<0.05, **P<0.01, #P<0.001 vs. the control group. PA, pachymic acid.