nicotiana alata
© Wikimedia CommonsNicotiana alata
A molecule found in the tobacco plant could be useful in killing cancerous cells in humans, Australian research has found.

The molecule, found in the pink and white flowers of the ornamental tobacco plant Nicotiana alata, is a key part of the plant's natural defence mechanism, allowing it to fight off fungal and bacterial infections.

After isolating the molecule, known as NaD1, La Trobe University biologists found that it also had the ability to identify and destroy cancer cells while leaving healthy cells unscathed.

"This is the holy grail - to develop specific agents which will only target cancer and not the normal healthy cells," cancer biologist Mark Hulett said.

Using the Australian Synchrotron in Clayton to see the molecule's structure in atomic detail the researchers, including structural biologist Marc Kvansakul, were also able to establish how the molecule tackled infection.

They found that the molecule used a complex mechanism, which first formed a pincer-like structure that gripped onto lipids in the outer layer of invasive cells. It then ripped them apart, making the cell explode and killing it.

"The mechanism is totally novel for any molecule," Dr Hulett said of the findings, which are outlined in the journal eLife published on Wednesday.

The ornamental tobacco plant is different to the tobacco plant grown for commercial use, although the two hail from the same genus.

The NaD1 molecule is found not only in the tobacco plant but in other living organisms including other plants and humans. Dr Hulett said it has never been clear how it worked or that it had the potential to treat cancer.

The research group will carry out pre-clinical trials to investigate whether the mechanism can be applied to treating cancer in humans. This could involve designing drugs to mimic the actions of the molecule or somehow prompting the naturally occurring molecule to target cancerous cells. However, Dr Hulett said the latter would likely prove more complex and there was the risk of interfering with the normal function of the molecule in the body.

Dr Hulett said it would be up to 10 years before a treatment could reach the market. The research was financed in part by the Melbourne biotech company Hexima and the Australian Research Council.