‘Grape seed’ fight against bowel cancer

Published in the journal PLOS ONE, the researchers say combining grape seed extracts with chemotherapy has potential as a new approach for bowel cancer treatment – to both reduce intestinal damage commonly caused by cancer chemotherapy and to enhance its effect.

Bowel cancer is diagnosed in more than 12,500 Australians every year. It mostly affects people 50 years of age and over, but can also occur in younger people.

Lead author, Dr Amy Cheah, says there is a growing body of evidence about the antioxidant health benefits of grape seed tannins or polyphenols as anti-inflammatory agents and, more recently, for their anti-cancer properties.

Dr Cheah, researcher in the School of Agriculture, Food and Wine, said: “Our research also shows that in laboratory studies grape seed taken orally significantly reduced inflammation and tissue damage caused by chemotherapy in the small intestine, and had no harmful effects on non-cancerous cells. Unlike chemotherapy, grape seed appears to selectively act on cancer cells and leave healthy cells almost unaffected.”

The researchers used commercially available grape seed extract, a by-product of winemaking.

Tannins extracted from the grape seed were freeze dried and powdered. The extract was tested in laboratory studies using colon cancer cells grown in culture.

The research showed grape seed extract:

• had no side effects on the healthy intestine at concentrations of up to 1000mg/kg;
• significantly decreased intestinal damage compared to the chemotherapy control;
• decreased chemotherapy-induced inflammation by up to 55%; and
• increased growth-inhibitory effects of chemotherapy on colon cancer cells in culture by 26%.

“Our experimental studies have shown that grape seed extract reduced chemotherapy-induced inflammation and damage and helped protect healthy cells in the gastrointestinal tract,” Dr Cheah says. “While this effect is very promising, we were initially concerned that grape seed could reduce the effectiveness of the chemotherapy.”

“In contrast, we found that grape seed extract not only aided the ability of chemotherapy to kill cancer cells, but was also more potent than the chemotherapy we tested at one concentration.”

Co-author and project leader Professor Gordon Howarth says: “Grape seed is showing great potential as an anti-inflammatory treatment for a range of bowel diseases and now as a possible anti-cancer treatment. These first anti-cancer results are from cell culture and the next step will be to investigate more widely.”