Chemical in fruit helps fight cancer: HKU
An antioxidant in fruit can increase 40-fold the effectiveness of a chemotherapy drug for cancers of the head and neck, a University of Hong Kong study has found.
The antioxidant, lupeol, is particularly rich in mangoes, olive seeds, grapes and strawberries.
The researchers discovered for the first time that lupeol can significantly suppress the activation of a protein which helps cancer cells grow. It is particularly effective against cancers in the nose, mouth and nasopharynx.
People cannot treat cancers by eating fruit, although the scientists believe it can help prevent cancers.
Using mice, they compared lupeol with the conventional chemotherapy drug cisplatin in the treatment of tongue cancer.
Results showed that lupeol was three times more effective than cisplatin in suppressing the growth of cancer cells. When lupeol was added to cisplatin, the drug worked 40 times better.
Professor of surgery Anthony Yuen Po-wing said: 'This is very encouraging news because lupeol, as a natural antioxidant, has very few side effects and it is much cheaper.'
The side effects of chemotherapy drugs include vomiting, hair loss and anaemia.
Dr Yuen said since most head and neck cancers, such as tongue cancer, belonged to the group known as squamous carcinoma cancers, the researchers believed lupeol could also effectively fight other head and neck cancers.
However, he said the research only showed lupeol extracted from fresh fruit and vegetables had anti-cancer effects. It was not known if dried or cooked fruit and vegetables could perform the same function.
The researchers' next step is to see if they can modify the chemical structure of lupeol to increase its solubility in water and formulate it into a drug which can be used on people.
According to the Hospital Authority, there were 2,087 new cases of head and neck cancer in 2004 and 665 people died of the diseases that year.
Fruit and vegetables rich in lupeol (with amounts in micrograms per milligram of dry weight)
Saw palmetto 45
Olive seed 32
SOURCE: UNIVERSITY OF HONG KONG