WOAD, once used as war paint by ancient Britons to strike fear into the hearts of their enemies, could now be used in the battle against cancer.
Scientists have discovered that the plant Isatis tinctoria, is a rich source of an anti-tumour compound glucobrassicin (GBS), which is also found in broccoli and Brussels sprouts, and is believed to be especially active against breast cancer.
A recent paper from Dr Stefania Galletti's research team at the University of Bologna, Italy, found that woad contains 20 times more of the cancer- fighting compound glucobrassicin (GBS) than broccoli. Like its relatives, the woad plant uses the compound as a defence mechanism to ward off insect pests, releasing extra levels of GBS when damaged by chemicals or after physical injury.
Researchers have boosted the plant's output dramatically by puncturing its leaves to mimic wounds left by insects and hope the quantities obtained will be high enough to use in clinical trials.
A recent study found a significant correlation between increased brassica consumption and reduced levels of lung cancer chemicals in smokers.
Other research indicates GBS may act against breast cancer by flushing out derivatives of the hormone oestrogen. However, levels of the compound are quite low in vegetables such as broccoli and it is mixed with other substances, making GBS difficult to extract and purify for patients' use in clinical trials.
Woad might provide scientists with the first cheap, rich source of the compound, the research suggests.
Woad was used by tribes living in ancient Britain to colour their faces and bodies. Among them were the Iceni, led by Queen Boudicca, who went into battle against the Romans naked but painted blue.
The plant dye was highly prized in the Middle Ages but was largely replaced by cheaper, imported indigo in the 16th century.