α-Viniferin (AVF), a trimer of resveratrol, is known to have an anti-inflammatory effect via inhibition of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS). It has been reported that up-regulated COX-2 and iNOS are expressed in colon cancer tissues of humans and rodents as well as pre-neoplastic aberrant crypt foci (ACF) of rodents. In this study, chemopreventive effects of AVF were assessed in Caco-2 cells as well as azoxymethane (AOM)-induced colorectal tumorigenesis in mice. Anti-tumor effect of AVF with regards to apoptotic induction was assessed by TUNEL and caspase-3 expression in human colon cancer Caco-2 cells. For development of ACF, AOM was administered with to mice intraperitoneally at a dose of 10 mg/kg once a week for 3 weeks. To induce colitis-related colon cancer, mice were administered a single dose of AOM (10 mg/kg) and 2% dextran sodium sulfate in drinking water. Mice treated with 0.05 and/or 0.1 mg of AVF by gavage showed significantly reduced development of ACF and colorectal tumors. Immunofluorescence detection in Caco-2 cells showed reduced COX-2 and iNOS expression, whereas cleavage of caspase-3 and apoptotic cell numbers increased upon AVF treatment. Immunostaining showed reduced expression levels of COX-2 and iNOS expression along with increased cleaved caspase-3 expression increased upon AVF treatment. These results suggest that AVF has chemopreventive effects on colorectal cancer via anti-inflammatory potential and pro-apoptotic activity.

Introduction
 Materials and Methods
  Animals and Chemicals
  Cell culture
  Western immunoblot analysis
  Immunofluorescence staining of COX-2, iNOS, and caspase-3 in Caco-2 cells
  TUNEL (TdT-mediated dUTP Nick-End Labeling assay)
  Effects of AVF during AOM-induced ACF development in mice
  Effects of AVF on colitis-related colon carcinogenesis model
  Immunohistochemistry of COX-2, iNOS, and caspase-3
  Statistical analysis
 Results
  Expression of COX-2, iNOS, and caspase-3 in Caco-2 cells
  Immunofluorescence staining of COX-2, caspase-3, and iNOS expression in Caco-2 cells
  Analysis of apoptosis in Caco-2 cells and colonic tumor tissues
  Inhibitory effect of ACF and immunohistochemistry of COX-2 and iNOS
  Tumor incidence and immunohistochemistry of COX-2, iNOS, and caspase-3
 Discussion
 Acknowledgements
 ORCID
 References

• Dong Hoon Kwak(College of Veterinary Medicine, Chungbuk National University)
• Sang-Kyung Shin(College of Veterinary Medicine, Chungbuk National University)
• So-Young Youm(College of Veterinary Medicine, Chungbuk National University)
• Tae-Wang Kim(College of Veterinary Medicine, Chungbuk National University)
• Youngsoo Kim(College of Pharmacy, Chungbuk National University)
• Byeongwoo Ahn(College of Veterinary Medicine, Chungbuk National University) Corresponding author