title: Withaferin-A Inhibits Colon Cancer Cell Growth by Blocking STAT3 Transcriptional Activity.
abstract: BACKGROUND
  Withania somnifera (known as Ashwagandha) is a medicinal plant used in the ayurvedic medicines in India. Withaferin-A, a withanolide derived from the leaf extract of W. somnifera, has been reported to exhibit anti-tumor activity against various cancer cells, such as leukemia, breast cancer and colon cancer cells.
  
  
  METHODS
  We investigated the anti-cancer effects of withaferin-A on the proliferation and migration of human colorectal cancer (HCT116) cells. And we evaluated the effects of withaferin-A on the transcriptional activity of STAT3 and the growth of HCT116 cells in xenograft mouse tumor model.
  
  
  RESULTS
  In the present study, we found that withaferin-A inhibited the proliferation and migration of HCT116 cells in a concentration-dependent manner. Treatment of HCT116 cells with withaferin-A attenuated interleukin-6-induced activation of STAT3, which has been implicated in the development and progression of colon cancer. To examine the effect of withaferin-A on HCT116 cells proliferation in vivo, we generated HCT116 cells xenograft tumors in Balb/c nude mice and treated the tumor bearing mice with or without withaferin-A intraperitoneally. Treatment with withaferin-A exhibited significant decrease in the volume and weight of tumors as compared to untreated controls.
  
  
  CONCLUSIONS
  The present study suggests that withaferin-A holds the potential to be developed as a small molecule inhibitor of STAT3 for the treatment of HCT116.
authors.affiliation: Department of Pharmaceutical Science and Engineering, Seowon University, Cheongju, Korea.
authors.forename: Bu Young
authors.initials: BY
authors.lastname: Choi
authors.affiliation: Department of Cosmetic Science and Technology, Seowon University, Cheongju, Korea.
authors.forename: Bong-Woo
authors.initials: BW
authors.lastname: Kim
keywords: Colorectal neoplasms; Heterografts; STAT3 transcription factor; Withaferin-A