The nature paper published today by Sylvie Diochot, from the Institut de Pharmacologie Mole´culaire et Cellulaire in France, and colleagues describes two black mamba venom toxin components (mambalgins) that block acid-sensing ion channels (ASICs) in peripheral, pain-sensing nerves and central pain pathways.
These toxins exert profound analgesic effects in mouse models of pain by blocking ASIC in these two pathways via both an opioid-dependent and opioid-independent pathway. Even the opioid-independent mechanism has the same strong effect as that of
opioids such as morphine.
The new opioid-independent pain-killing mechanism is very interesting, because it may reduce the risk from overdoses that cause respiratory depression – the most dangerous form of opioid overdose. It may also reduce the risk of addiction associated with opioid drugs.
Pain responses in animals can be due to drowsiness or muscle relaxation caused by the agent being tested. According to the authors, the experiments described in the paper show no signs of these confounding effects that could give a false impression of pain-killing action.
From this paper, it looks like the black mamba toxin may contain a new component, mambalgin, that can be used to develop new pain therapies.
What happens now?
It’s possible, but unlikely, that one of the mambalgin proteins identified will be used as medicine without any more changes being made to it.
But pharmaceutical companies and publicly funded research groups will probably look for small molecules that can mimic the actions of mambalgins to produce potent, orally available drugs to treat pain. Unfortunately, this process could take up to ten years to complete.
Pain is poorly treated currently and there is a dire need for new and more effective drugs to improve the quality of life of people with pain.
So, we should wish these research groups the best of luck!