PA inhibits tumor xenograft growth in vivo. a Anti-tumor activity of PA in nude mice bearing NCI-H23 tumors. Vehicle control and PA (10, 30 and 60 mg/kg) were administered for 3 weeks (5 days/week) by ip injection. Tumor volume was monitored. b Body weight of the mice. c H&E staining of the paraffin-embedded sections of various tissues (lung, liver, kidney and spleen) obtained from mice were performed to assess whether there were any abnormalities caused by the treatment. Scale bars are 100 μm. Data in the graphs represent the mean ± SD (n = 6). **p < 0.01 versus vehicle control.