Scientists Target New Painkillers from Spider Venom

Scientists in Australia have made an important discovery about spider venom that eventually could lead to a new class of painkillers. Australia is a natural fit for this research - plethora of venomous animals.

Spiders use their venom to immobilize or kill their prey. Researchers from the University of Queensland isolated seven peptides (the building blocks of proteins) in spider venom that blocked the molecular pathway responsible for sending pain signals from the nerves to the brain. 

One peptide in particular, from a Borneo orange-fringed tarantula, had the right structure, stability and potency to potentially become a painkilling drug. The study was recently published in the British Journal of Pharmacology.

Traditional painkillers such as morphine and hydrocodone can be addictive. Abuse of these drugs has soared in recent years, prompting stricter regulations from the U.S. Drug Enforcement Administration. Researchers say pain killers made from spider venom won’t be abusive/addictive

“Spider venom acts in a different way to standard painkillers,” said Jennifer Smith, a research officer at the University of Queensland’s Institute for Molecular Bioscience.

Researchers don’t expect a painkiller derived from the venom will be addictive because it blocks a specific channel that transmits pain to the brain. Opiate painkillers, by contrast, block widespread opioid receptors on cells in the brain, spinal cord and other organs.

Venom Could Go a Long Way in Medicine

Spiders aren’t the only venomous creatures with medicinal potential. Researchers in France have found that ingredients in the venom from Africa’s black mamba snake, one of the world’s deadliest, had painkilling properties as potent as morphine. 

A drug derived from the venom of the sun anemone, which lives on reefs in the Caribbean, is currently being tested in the U.S. on people with psoriasis and could also be used to treat other autoimmune disorders such as multiple sclerosis and rheumatoid arthritis.

Scientific interest in venom’s painkilling properties stems from an earlier discovery by geneticists of a rare mutation in some people—in a gene known as SCN9A—that eliminates their ability to feel pain. While they can experience touch, warmth and other tactile functions, their sense of smell and pain are inhibited

Some venoms from spiders and other animals and plants have been found to mimic the effects of the gene mutation.

The Data from the Study:

• Analyzed spider venom from 205 species found locally and in other countries (there are currently about 45,000 known species of spiders in the world).
• Isolated various active peptides from the venom. 
• Each peptide was studied to see how it would affect specific pain targets known as ion channels, which transmit pain signals through the body.

Results

• About 40% of the tested spider species contained at least one peptide that blocked pain channels. 
• Researchers plan to conduct animal studies to test the peptides’ clinical potential, looking for any unforeseen side effects, whether the substances break down in the body and other outcomes.
• Researchers have a large library of different venoms from different spider species and we’re branching out into other arachnids: scorpions, centipedes and even assassin bugs

Samadi's Take

Research is scientifically promising, but it is too early to say when this might be in the clinic or a product would be available. Medical community is eager to identify new medications to treat chronic pain, which affects about 15% of all adults.

Experts estimate that as many as 1 in 5 people worldwide suffer from chronic pain and existing pain treatments often fail to give sufficient or long-term relief. 

Pain's economic burden is also huge, with chronic pain estimated to cost $600 billion a year in the U.S. alone. Of the seven promising compounds they identified, they said one was particularly potent and also had a chemical structure that suggested it would have the kind of chemical, thermal and biological stability needed for making a drug. Untapping this natural source of new medicines brings a distinct hope of accelerating the development of a new class of painkillers.