San Francisco Frontiers - US study tests psilocybin to fight cancer side effects

The study published Thursday in the journal Science involved tests on rats and certain human tissues as researchers looked at using psilocybin to fight a condition called peripheral neuropathy, which affects millions of people around the world.

It is a nerve ailment that hits about three quarters of all people who undergo chemo and commonly causes numbness and tingling, Patrick Dougherty, a co-author of the study, said in a call with reporters.

But a third of that group will develop non-stop, burning pain, said Dougherty, a pain treatment specialist at the University of Texas MD Anderson Cancer Center.

The symptoms can lead to trouble walking and other debilitating complications that can last after a person finishes chemotherapy, and even remain with them for life.

And it is not just a quality-of-life issue. This complication also affects a cancer patient's chances of survival because sometimes the side effects are so bad they force doctors to cut back on chemo or stop it altogether.

- Protecting nerves -

It was almost by accident that these researchers found that psilocybin can help cancer patients.

The team was initially studying how the disease manages to hijack nerve cells in order to grow.

And the researchers were surprised to see the mushroom ingredient -- it was being used to study a brain pathway regeneration concept called neuroplasticity -- actually prevented the emergence of peripheral neuropathy.

Later experiments highlighted psilocybin's role in protecting nerve cells and stimulating inside them the transport of mitochondria, often referred to as a cell's powerhouse.

This is key because chemo destroys the microscopic railroads that allow mitochondria to send energy all the way to the tips of people's hands and feet, killing off nerve endings there.

Psilocybin also seems to act on the brain, preserving electrical activity that chemotherapy thwarts.

In rodents, taking two doses of psilocybin before chemo was enough to prevent the appearance of painful hypersensitivity during as many as six rounds of treatment. And it did this without affecting the animal's immune system or hindering the cancer-fighting action.

- Careful with self-medicating -

"This is a highly promising finding," said Kristy Townsend, a professor of neurobiology at The Ohio State University who was not involved in the study.

And psilocybin's nerve-protecting quality does not seem to be linked to its hallucinogenic effects because a non-hallucinogenic analogue had the same effect in a lab test, she added.

Before the treatment can be made standard for people, testing will be needed to see if it is safe and effective, said Townsend.

This will be a long, slow process though it should be eased by a boom in medical research on psychedelic substances and a Trump administration executive order in April to speed up research and regulatory reviews, these scientists say.

The MD Anderson Cancer Center plans to launch clinical tests with psilocybin on cancer patients later this year.

Meanwhile it is important for cancer patients to avoid using magic mushrooms on their own as treatment, the researchers warned.

Psilocybin is legal in a few US states.

The drug has an "amplifier" effect and cancer patients who take it without supervision could feel more stressed and anxious than they already are because of their cancer diagnosis, said Gregory Jones, a psychiatrist who took part in the study released Thursday.

"If you put somebody in adversity under these psychedelic substances, you can get much worse," Jones said.

Q.Nelson--SFF