January 30, 2012. Researchers at the University of Colorado report online on January 19, 2012 in the journal Carcinogenesis that grape seed extract shows an ability to reduce the growth of head and neck squamous cell carcinoma when administered to cell cultures and mice.
“It’s a rather dramatic effect,” commented lead researcher Rajesh Agarwal, PhD, who is a professor at the University of Colorado Skaggs School of Pharmacy and Pharmaceutical Sciences. “Cancer cells are fast-growing cells. Not only that, but they are necessarily fast growing. When conditions exist in which they can’t grow, they die.”
Dr Agarwal and his associates tested the effects of grape seed extract in cultures of human head and neck squamous cell carcinoma as well as normal human epidermal cells. The researchers observed a reduction in growth, along with cell cycle arrest and programmed cell death in the cancerous cells. Grape seed was found to damage the DNA of the cancer cells while inhibiting its repair. The authors attribute grape seed’s growth inhibitory, DNA-damaging and apoptotic effects to the accumulation of intracellular reactive oxygen species, a phenomenon that was reversed by the administration of the antioxidant N-acetylcysteine. Similarly, in an experiment involving mice that received transplanted head and neck squamous cell carcinoma tumors, animals that received grape seed extract had a reduction in cancer cell growth compared with those who did not receive the extract. In both experiments, healthy tissue remained unharmed.
“We saw absolutely no toxicity to the mice, themselves,” Dr Agarwal emphasized. “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.”
The researchers hope to test grape seed in human patients who have failed first line therapies.