Grape seed extract contains powerful antioxidants called proanthocyanidins. The antioxidant power of proanthocyanidins is many times stronger than vitamin C and vitamin E. Antioxidants neutralize harmful radicals (toxic byproducts of metabolic functions) and protect against inflammation, cancer, and age-related diseases. Now research reports that grape seed extract has antitumor effects against colorectal cancer cells.
The study, published in Clinical Cancer Research, investigated the in vitro effects of grapeseed extract on human colorectal cancer cell cultures and the in vivo effects of grapeseed extract on mice with implanted human colorectal cancer cells. For the in vitro experiment, researchers at the University of Colorado Health Sciences Center in Denver, Colorado, treated two cultured human colorectal cancer cell lines with three different doses of grape seed extract in DMSO or DMSO alone. For the in vitro experiment, the scientists administered a treatment with grapeseed extract or no treatment to mice with implanted human colorectal cancer cells.
The in vitro findings revealed that grapeseed extract caused a dose- and time-dependent inhibition of tumor cell growth and an increase in programmed cell death. There was a 92 percent reduction in live cells in the cell line that received the highest dose of grapeseed extract. The researchers found that grapeseed extract increased Cip1/p21 protein (stops cell growth) and decreased cyclin proteins and cyclin-dependent kinases (promote cell division)
The in vivo findings showed a 44 percent reduction in tumor cells in the mice treated with grapeseed extract, compared to the untreated mice. Findings also revealed a significant increase of Cip1/p21 protein levels in the tumor cells. This suggests a similar effect to that found in the cultured cells.
"Grapeseed extract may be an effective chemopreventive agent against colorectal cancer, and that growth inhibitory and apoptotic effects of grapeseed extract against colorectal cancer could be mediated via an up-regulation of Cip1/p21," the study authors conclude.
REFERENCES:
1. Kaur M et al. Grape seed extract inhibits in vitro and in vivo growth of human colorectal carcinoma cells. Clin Cancer Res 2006 Oct 15;12(20 Pt 1):6194-202.
Posted by Elaine Gavalas on November 15, 2006 12:43 PM
