A little-known native rainforest tree could be about to become big news. The Macleay laurel, Anopterus macleayanus, is a small rainforest tree endemic to South East Queensland and Northern New South Wales. So far it has not attracted the attention of the horticulture industry, although it is an easy to grow native that works well in container culture and as an indoor plant. It is however attracting the attention of medical researchers.
Researchers at NatureBank have screened a multitude of samples from Queensland native plants looking for new compounds that are active against prostate cancer. Phytochemicals extracted from the Macleay laurel and another little-known native tree, the orange bark tree, Maytenus bilocularis, have shown very promising results against a particularly difficult to treat form of prostate cancer. Further investigations by the team showed that compounds extracted from the Macleay laurel have very significant potential as broad-spectrum cancer treatments.
What makes them so exciting is that they work very differently compared with existing cancer treatments. Drug resistance is an ongoing issue in many fields of medicine, including cancer treatment, so the search for new treatments is ongoing. The journey from plant to modern medicine is one that is mostly unseen. Active compounds need to be isolated from plants, tested, researched extensively, and usually artificially synthesised to ensure consistent and reliable supply.
While these medicines may end up being mass produced by chemical synthesis, without the plant in the first step, they would not have been developed at all. Plants are the forgotten heroes of so much of our modern medicine. The majority of cancer drugs in use today are directly derived from natural products, mostly found in plants. Finding a new plant compound that leads to the development of a new drug is a bit of a needle in a haystack scenario. Where do researchers start looking? When it comes to the unique and often under studied flora of Australia, the journey starts at NatureBank.
NatureBank is a research facility located at Griffith University’s Institute for Drug Discovery in Brisbane. NatureBank is a huge library of plants, mushrooms and marine invertebrates. This library contains specimens of approximately 80 per cent of Queensland’s flora, held as powdered samples, as whole plant extracts and as fractionated samples.
A fractionated sample results from chemical separation in which certain plant chemicals (phytochemicals) are purified from the rest of the complex plant extract, allowing those chemicals to be researched as individual chemical compounds. The purpose of the library is to provide research scientists access to plant compounds as they look for what may be the next wonder drug, new food additives, agrochemical products, nutraceuticals or even cosmeceuticals.
Scientists at NatureBank, work to isolate compounds from the plant samples, and then screen these compounds against various disease conditions. A huge number of plant compounds need to be screened to find one with strong medical potential. When one compound is identified, very significant and focussed research is needed to find out if this compound is likely to be safe and viable as a new treatment or medicine. Without financial input from large pharmaceutical companies this scale of work is almost impossible to fund.
The Macleay laurel is just one of many Queensland plants that have showed promise over the years. In another project, a local farmer is growing a crop of another plant for NatureBank, to assist with ongoing research for a treatment of Barber’s pole worm, a serious livestock parasite. The small team at NatureBank is working to try and conduct as much preliminary screening of the samples they have as possible. This then allows them to provide prequalified samples to researchers worldwide who are keen to investigate further.
It has taken many years to build up the current library of more than 30,000 flora and fauna samples. This unique facility also contains more than 21,000 extract samples and over 105,000 fractions for testing against a variety of diseases.
The NatureBank library of samples is available to scientists worldwide to access samples for all sorts of research projects. A South Korean cosmetics company is currently working with samples to find additives for skin creams. A Danish company is screening samples looking for anti-inflammatory properties, which may improve treatments for eczema and psoriasis. Yet another international company is accessing NatureBank samples looking for compounds effective in treating the virus that causes COVID 19. Wouldn’t it be exciting if the next big thing in all these areas came from one of our indigenous plants?
While it would be wonderful to see greater appreciation and conservation of our natural biodiversity for its own sake, it certainly wouldn’t hurt to have the whole world looking at our native plants in a new and promising light. In the meantime, this preliminary work in screening plant compounds adds hugely to our knowledge and understanding of our unique flora. Find out more about this very Australian library here.