Magnolia compound may have anti-cancer properties

In collaboration with the Press Association

A natural substance found in the fruit or 'cone' of the magnolia tree blocks a key process that cancer cells use to grow, US research suggests.

The compound could form the basis for a new generation of anti-cancer drugs.

Scientists at Emory University School of Medicine found that the compound honokiol, which has long been used in Japanese and Chinese herbal medicine, appears to block the 'Ras' pathway - one of the cellular 'communications pathways' which many tumours use to survive and grow.

Honokiol was first shown to inhibit tumour growth in mice in 2003 and the new research sheds light on exactly how it does so.

The researchers studied the effect of honokiol on human breast cancer cells in the laboratory and found that it is "particularly potent" against tumours which were heavily reliant on the 'Ras' pathway for their growth signals. Faults in the Ras genes - a family of three related genes which form a key part of the pathway - have been found in around a third of human cancers. Despite intensive research over the 25 years since their discovery, scientists have so far failed to develop any treatments that target Ras genes.

But the latest finding suggests that honokiol prevents Ras from turning on an enzyme called phospholipase D, the next 'step' in the Ras signalling pathway.

Phospholipase D helps cancer cells to survive the natural process of cell suicide (apoptosis) so blocking its action could help to destroy cancer cells and allow chemotherapy drugs to have their intended effect.

Emory researcher Dr Jack Arbiser, who is an associate professor of dermatology, commented: "Knowing more about how honokiol works will tell us what kinds of cancer to go after. Honokiol could be effective as a way to make tumours more sensitive to traditional chemotherapy."

The findings are published in the journal Clinical Cancer Research and the team hope to start clinical trials involving the compound in the near future.