From bush to bedside: cool things in nature that become medicines to treat disease

Brendan Shaw

"When it comes to discovering medicinal products found in nature, we’ve barely scratched the surface."

- Piper, R. et al, 2018 "Nature is a rich source of medicine – if we can protect it", The Conversation

Amid all the arguments that go on in health care, the science that goes on behind it all sometimes really blows my mind.

I’ve been working in the pharmaceuticals and healthcare policy and business space for decades now, but it still never ceases to amaze me when I hear of some new medicine or vaccine being developed after some unassuming compound has been discovered in nature.

It’s that great space where science and technology meet environment and nature to benefit everybody.

Medicines from nature

Of course, there are numerous examples in the history of medical science where obscure or unknown compounds in nature have been discovered to have medical properties and turn out to be groundbreaking treatments for disease. These can come from plants and animals.

In many cases, people have known about these treatments for thousands of years. Traditional medicine from indigenous peoples around the world have helped inspire many modern medicines, and there's evidence that Neanderthals in Europe 40,000 years ago self-medicated through chewing willow bark for aspirin and potentially mould for penicillin.

A few of my favourite examples in this space include:

Aspirin – one of the most widely used medicines in the world, forms of aspirin originally came from the bark of the willow tree. Around 2,500 years ago in Ancient Greece, Hippocrates recommended the juice of willow leaves to relieve the pain of childbirth. Used for headaches and pain relief for millennia and refined over years since the 19th century, today there are many uses for aspirin including as an anti-inflammatory treatment, as protection from heart attacks and strokes and, potentially, as a cancer treatment.

Scorpion venom – out of something that usually strikes fear into human beings, the poisonous venom from spiders and scorpions has been adapted and used to treat tumours in the brain. For example, scientists are developing a CAR-T cell therapy based on chlorotoxin, a compound derived from scorpion toxin that binds preferentially to unique targets on brain cancer cells. A company has been launched to commercialise this treatment. The technology allows therapies to target brain cancer cells but leave healthy brain cells unaffected.

Yew tree – paclitaxel, a compound extensively used in cancer treatment, was originally derived from the bark of the yew tree from the Pacific Northwest of the United States. First Peoples living in North America drank tea brewed with yew tree leaves to treat rheumatism and complications from childbirth. Today paclitaxel is on the WHO’s Essential Medicines List and is used as a chemotherapy for a variety of cancers. Since its discovery as a modern cancer treatment in the 1960s, millions of patients have benefited from its use.

Lizard spit – a well-known example to many, the saliva of the Gila Monster – a lizard found in the deserts of south-western United States and north-western Mexico, was found to have compounds that help to treat diabetes in humans by helping patients with diabetes secrete insulin. Today, the medicine, exenatide, is widely prescribed to patients living with diabetes and has led to more recent diabetes treatments.

Dubosia tree – compounds from the dubosia tree native to Australia help relieve stomach disorders, motion sickness and are used in eye surgery. Known and used by indigenous First Australian peoples for thousands of years, modern medicine has developed it into a commercial treatment. Used by Allied soldiers in World War II to avoid sea sickness in the D-Day landings, today it is grown in plantations in Australia to provide global supplies.

Blushwood tree - a new antibiotic is being developed to potentially prevent infections in wounds. The compound, EBC-1013, acts against bacteria, prevents infection and helps stimulate skin repair. At a time of rising global antimicrobial resistance (AMR) from evolving superbugs, this could be a welcome development. The compound comes from the sap of the blushwood tree, which is native to Australia and only grows in the rainforests in the Atherton Tablelands in tropical Far North Queensland.

Cone snail venom - a major painkiller for humans, ziconotide, which is many times more powerful than morphine, has been derived from the venom of the cone snail which is widely dispersed across the Indian and Pacific Oceans. The medicine is a specialised, very strong painkiller only given in hospital to patients in extreme pain. It's been synthetically isolated and manufactured to replicate the compound which is found in the snail's venom.

Penicillin - in probably one of the most famous examples, penicillin was sort of accidentally discovered by Alexander Fleming in 1928 when he returned from holidays to find mould growing in his petri dishes and no bacteria living near the mould. First used in World War II to stop soldiers dying from infections when wounded, it become the first major antibiotic that went on to save millions of lives.

Funnel web spider venom - clinical trials are about to get underway to test a compound from the venom from the world's deadliest spider to see if it can prevent cell damage caused by heart attack and strokes. The venom of the funnel web spider found on K'gari (Fraser Island) in Australia, is about to start clinical trials after earlier research found it potentially prevents brain damage from strokes.

Science, discovery and nature

It is a credit to human scientific endeavour that we can identify such compounds and develop them into medicines that treat human disease. The world is a better place because of this.

Of course, as you might expect, this activity is not without its controversy.

For a start, there’s the issue of whether companies developing such compounds should be able to derive commercial benefit from such treatments. Debates sometimes arise over whether scientists, universities, companies and governments should be able to patent compounds derived from nature in the first place.

However, while there needs to be some level of caution here, at the same there's a basic fundamental question that needs to be asked: 'Would that medicine derived from a compound in nature be a medicine today if it weren't for the work of scientists and companies developing that medicine?' I would suggest that the answer is almost certainly 'no'.

I'm not going to debate all of this at length here (that’s for another blog). Suffice to say that the dividing line should be where something changes from being a ‘discovery’ in science to a ‘technological development’ in medicine, coupled with the fair sharing of benefits from the technology for those with rights to it where traditional medicine might be involved.

There is a whole international convention on this governing how the benefits of biodiversity are shared among different members of society. The aptly named ‘Convention on Biodiversity’ has an extensive system of agreements and supporting infrastructure around the 'Nagoya Protocol'. The Protocol has been negotiated over many years to help reach international agreement on who ‘owns’ things in nature – if at all. It aims to support benefit sharing arising from the utilisation of genetic resources in a fair and equitable way. This includes natural substances occurring in nature that end up as the basis for new medicines to treat disease.

The CBD covers everything from traditional knowledge sharing for first nations indigenous people, through to pathogen sharing in the event of pandemics and outbreaks. There are all sorts of complex issues that come out of this that you can read more about here.

More broadly, the great thing is that we are finding ways to develop new medicines.

In the long view, what's happened is that humanity has turned things that existed in nature in the bark of a tree or the saliva of a lizard into cheap and effective treatments that now exist in perpetuity and save thousands of lives every year.

Environmental issues

There’s also the environmental issue of the impact of the exploitation of such compounds for human benefit. We need to ensure that, in expanding on something in nature to benefit humanity, we don’t also compromise or destroy the environment that gave us the compound in the first place.

In the example of the Pacific yew tree used to make paclitaxel, in the past there have been major environmental sustainability problems in its production. Up until 1994 when scientists worked out how to synthesise the compound, the production of paclitaxel by stripping the bark off the slow-growing yew tree threatened its very survival.

Equally, the amazing scientific discoveries of new things in nature that treat disease remind us that we need to preserve biodiversity and ecosystems in the environment and ensure that animal rights are protected as much as possible.

Ongoing environmental destruction and species extinction carries with it the real risk that a future cure for cancer or breakthrough new antibiotic to treat superbugs is destroyed and lost before it’s even been discovered. One estimate is that we are losing one important drug every two years due to environmental destruction.

While a fictional Hollywood move, the film ‘Medicine Man’ starring Sean Connery does a reasonable job of highlighting these issues. Connery’s character races against time to identify a compound in the Amazon jungle that cures cancer he's learned about from the traditional medicine of the local indigenous tribes as the bulldozers threaten to demolish everything.

While the issues are complex and ongoing, the fundamental reality that these treatments for disease come from nature is amazing.

It’s a testament to our science, our ingenuity and our ability to successfully manage our interaction with the natural environment. Something we’re really only just beginning to understand.

#science #medicine #history #CBD #biodiversity