Scientists in France say they're hoping to develop new anti-cancer drugs, based on the ingredients of a herbal medicine used to treat leukaemia in China for thousands of years.

A report in the journal "Nature Cell Biology" says researchers have isolated the active ingredient of the Chinese herbal medicine, Danggui Longhui Wan .

The scientist say tests appear to show that the chemical stops tumour cells from growing out of control by blocking cells' ability to divide.

The BBC Science Correspondent says that although the use of traditional Chinese herbal medicines is based on age-old practical experience, few remedies have been tested in the laboratory under strict scientific conditions.