October 4, 2012
Venom From Lethal Black Mamba As Strong As Morphine, But Without Side Effects
redOrbit Staff & Wire Reports - Your Universe Online
The venom from one of the world´s most dangerous snakes contains a potent painkiller that works as well as morphine, but without the toxic side effects, French researchers reported on Wednesday.
The deadly black mamba, which uses neurotoxins to paralyze and kill its prey, is one of the fastest and most lethal snakes in Africa. Its venom is among the fastest acting of any snake species, and a bite is lethal if not treated with antivenom. The poison works by attacking the victim´s central nervous system and causing respiratory paralysis.
The French researchers evaluated the venom from 50 snake species before they identified the black mamba's pain-killing proteins - called mambalgins.
The study, which used mice, found that these peptides bypass the brain receptors targeted by morphine and other opioid compounds that can cause side-effects such as headaches, difficulty thinking, vomiting, muscle twitching and risk of addiction.
Since the mambalgins target pain through a completely different way, they should produce very few side effects, the researchers said.
"We have identified new natural peptides, mambalgins, from the venom of the snake Black Mamba that are able to significantly reduce pain in mice without toxic effect," said study co-author Anne Baron of France's Centre National De La RecherchÃ© Scientifique, in an interview with the AFP news agency.
"It is remarkable that this was made possible from the deadly venom of one of the most venomous snakes," she said, adding that researchers are unsure why the mamba would produce mambalgins.
"(It) is surprising that mambalgins, which represent less than 0.5 percent of the total venom protein content, has analgesic (pain-relief) properties without neurotoxicity in mice, whereas the total venom of black mamba is lethal and among the most neurotoxic ones."
"It is remarkable that this was made possible from the deadly venom of one of the most venomous snakes.”
Lead researcher Dr. Eric Lingueglia from the Institute of Molecular and Cellular Pharmacology said the pain-relieving effects of mambalgins were equivalent to those of morphine.
"When it was tested in mice, the analgesia was as strong as morphine, but you don't have most of the side-effects,” he told BBC News.
Since pain works similar in mice and humans, Dr. Lingueglia hopes to develop painkillers that could be used in his clinic. Indeed, tests on human cells in the laboratory have already demonstrated that mambalgins have similar chemical effects in people.
However, "it is the very first stage, of course, and it is difficult to tell if it will be a painkiller in humans or not. A lot more work still needs to be done in animals,” he said.
Dr. Nicholas Casewell, an expert in snake venom at the Liverpool School of Tropical Medicine, speculated that the analgesic effect of mambalgins may work in combination "with other toxins that prevent the prey from getting away" or may just affect other animals differently than mice.
Baron said a patent has been issued, and a pharmaceutical company is evaluating potential opportunities.
The study was reported online October 3 in the journal Nature.