Dr. Weeks’ Comment: I have championed the opinion, over the past 20 years, that all healthy natural plants on earth have anti-cancer properties; they wouldn’t be able to survive without this adaptive advantage. Look carefully at the blackberry, the fig, the pine, the morning glory – in each plant you will find molecules which are anti-cancer. The essence of being a healthy plant is itself anti-cancer. This curious concept is becoming better accepted with each research into individual plants: here we look at the seed of the common grape. Grape seed extract, like vitamin C and like fermented soy, selectively targets cancer cells. The mechanisms have been worked out: pro-oxidation against the relatively vulnerable cancer cell. But what your oncologist needs to know is that cancer cells respond to oxidative stress differently than healthy cells do. Therefore, using anti-oxidant therapy is NOT contraindicated with chemotherapy and radiation since it benefits healthy cells and does not rescue cancer cells.
RX Organic grapes rich in grape seeds and grape skins
Grape seed extract kills head and neck cancer cells, leaves healthy cells unharmed
Nearly 12,000 people will die of head and neck cancer in the United States this year and worldwide cases will exceed half a million
“It’s a rather dramatic effect,” says Rajesh Agarwal, PhD, investigator at the University of Colorado Cancer Center and professor at the Skaggs School of Pharmaceutical Sciences. It depends in large part, says Agarwal, on a healthy cell’s ability to wait out damage.
“Cancer cells are fast-growing cells,” Agarwal says. “Not only that, but they are necessarily fast growing. When conditions exist in which they can’t grow, they die.” Grape seed extract creates these conditions that are unfavorable to growth. Specifically, the paper shows that grape seed extract both damages cancer cells’ DNA (via increased reactive oxygen species) and stops the pathways that allow repair (as seen by decreased levels of the DNA repair molecules Brca1 and Rad51 and DNA repair foci).
“Yet we saw absolutely no toxicity to the mice, themselves,” Agarwal says.
Again, the grape seed extract killed the cancer cells but not the healthy cells. “I think the whole point is that cancer cells have a lot of defective pathways and they are very vulnerable if you target those pathways. The same is not true of healthy cells,” Agarwal says.
The Agarwal Lab hopes to move in the direction of clinical trials of grape seed extract, potentially as an addition to second-line therapies that target head and neck squamous cell carcinoma that has failed a first treatment.
Mol Carcinog. 2011 Jul;50(7):553-62. doi: 10.1002/mc.20739. Epub 2011 Jan 25.
Grape seed extract upregulates p21 (Cip1) through redox-mediated activation of ERK1/2 and posttranscriptional regulation leading to cell cycle arrest in colon carcinoma HT29 cells.
Kaur M, Tyagi A, Singh RP, Sclafani RA, Agarwal R, Agarwal C.
Department of Pharmaceutical Sciences, School of Pharmacy, University of Colorado Denver, Aurora, USA.
Abnormalities in cell cycle progression provide unlimited replicative potential to cancer cells, and therefore targeting of key cell cycle regulators could be a sound cancer chemopreventive strategy. Earlier, we found that grape seed extract (GSE) increases Cip/p21 protein level and inhibits growth and induces apoptosis in human colon carcinoma HT29 cells both in vitro and in vivo. ……. GSE was found to increase the stability of p21 message with resultant increase in p21 protein level, but it did not alter the protein stability to a great extent. Importantly, knock-down of p21 abrogated GSE-induced G(1) arrest suggesting that p21 induction by GSE is essential for its G(1) arrest effect. Together, our results for the first time identify a central role of p21 induction and associated mechanism in GSE-induced cell cycle arrest in HT29 cells.
RX Organic Brocolli, Brussles Sprouts, Cabbage, Cauliflower – cruciferous vegetables rich in sulforaphanes
Cancer Chemother Pharmacol. 2006 Feb;57(3):317-27. Epub 2005 Sep 17.
p53-independent G1 cell cycle arrest of human colon carcinoma cells HT-29 by sulforaphane is associated with induction of p21CIP1 and inhibition of expression of cyclin D1.
Shen G, Xu C, Chen C, Hebbar V, Kong AN.
Department of Pharmaceutics, Ernest Mario School of Pharmacy, Rutgers, The State University of New Jersey, Piscataway, 08854, USA.
Isothiocyanate sulforaphane (SFN) is a potent cancer chemopreventive agent. We investigated the mechanisms underlying the anti-proliferative effects of SFN in the human colon carcinoma cell line, HT-29. We demonstrate that SFN inhibits the growth of HT-29 cells in a dose- and time-dependent manner. Treatment of serum-stimulated HT-29 cells with SFN suppressed the re-initiation of cell cycle by inducing a G(1) phase cell cycle arrest. At high doses (>25 microM), SFN dramatically induces the expression of p21(CIP1) while significantly inhibits the expression of the G(1) phase cell cycle regulatory genes such as cyclin D1, cyclin A, and c-myc. ….. Furthermore, the activation of the ERK and p38 pathways by SFN is involved in the upregulation of p21(CIP1) and cyclin D1, whereas the activation of the JNK pathway plays a contradictory role and may be partially involved in the downregulation of cyclin D1…..
Eat the rainbow!