Black mamba venom may be a super painkiller!

French scientists have recently identified that the toxic venom of the black mamba, one of Africa's most dangerous and feared snakes, has a huge potential for its use in medicine. The research, carried out by Dr. Eric Lingueglia from the Institute of Molecular and Cellular Pharmacology near Nice, has identified that the snake's poison contains a unique class of chemicals called mambalgins, which act as painkillers in mice that are as strong as morphine but have none of its associated side effects.

The black mamba, Dendroaspis polylepis, is named after the dark skin inside its mouth rather than after the colour of its scales. As well as being among the most poisonous snakes in the world, the 3 metre long mamba is also the fastest and can even outrun humans. These attributes, along with its highly aggressive nature, have made the snake highly feared among all the African peoples that live alongside it.

These properties of black mamba venom are of huge interest to the healthcare sector because, despite its heavy use, morphine is highly addictive and has many severe side effects for those taking the drug, which include headaches, a reduction in their thinking capacity, nausea and muscle spasms. A new painkiller then, which is effective enough to remove the same agonising pains as morphine but with none of its side effects would be like a 'magic bullet' in pharmacology, being hugely popular among both doctors and their patients.

Research has identified that these useful mambalgins may work in such a beneficial way because they operate via a previously unseen neural pathway that is not targeted by any other studied venom or by the palliative drugs currently in production. Dr. Nicholas Casewell, a world-leading expert in snake venom from the Liverpool School of Tropical Medicine, is avid over the potential implications of black mamba toxins to medicine and has said that mambalgins are "a really great example of drugs from venom, we're talking about an entirely new class of analgesics".

Dr. Lingueglia believes that this rather surprising property of black mamba venom may be as an intentional effect of the poison, which helps to incapacitate the snake's prey so that it is less likely to escape; or may be due to a chance, but useful, fluke in mice, resulting from the differences in brain chemistry between the rodents and the snake's usual prey.

Whatever the reason for the venom's remarkable analgesic properties in mice however, scientists are excited about the discovery and are hopeful that the toxins will have the same effects in humans as our brain chemistry is very similar to that of the rodents (which is why mice are often used in scientific studies). It is likely that there will be extensive research into mambalgins in the near future, which will hopefully lead to a new drug that acts as a safer alternative to morphine.

Paralysed rats walk again!

An interesting new study has revealed that it has been successful in enabling artificially paralysed rats to regain motor function and walk again! These findings have exciting implications for helping humans to recover from spinal damage and Dr. Vissel from the Garvan Institute of Medical Research in Sidney has said that: "we are on the edge of a truly profound advance in modern medicine - the prospect of repairing the spinal cord after injury".

Much of the physiology of the common rat (Rattus norvegicus) is very similar to that of humans, which makes the animal extremely useful for scientific study.

The study, carried out by researchers at the Swiss Federal Institute of Technology (EPFL), involved severing the spinal cord of rats in two separate places at their 7th and 10th thoracic vertebrae (which form the section of your spine behind your ribs). This was sufficient to completely disrupt their voluntary muscle control; leaving the rats paralysed and unable to move. The researchers then injected their spinal cords with a solution of various electrolytes such as serotonin and dopamine receptor agonists, which increased the activity levels of the nerves and stimulated the rats' nerves even further using electricity (at 40Hz if anyone's interested...) by attaching diodes to various segments of their spines near their base.

By supporting the movement of the rats in a robotic harness, researchers found that they were eventually able to walk, run and even climb stairs when their spine was being stimulated! This behaviour was gradually 'built up' however, as the rats appeared to have had to relearn how to move so the research doesn't suggest that there is an 'instant fix' to spinal damage; rather that it is possible with extensive physiotherapy in conjunction with modern medical techniques, such as those used in this experiment.

"It is completely unexpected to see this level of recovery." Professor Courtine (EPFL)

Thus, this exciting experiment suggests that recovery after spinal damage is perfectly possible for humans and that such individuals will eventually be able to live normal and independent lives. Experts point out however that although this technique has worked well in rats, it may not work in humans. 'Real life' injuries to the spine are much more complicated than those that were artificially introduced in this experiment and humans are much larger, more complicated organisms than rats. The study does provide hope however, and, as stated by Dr. Bacon (the director of research at Spinal Research): "this is a robust demonstration that medical research is moving in the right direction and restoring function after paralysis can no longer be dismissed as a pipedream".

Reference

van den Brand R., Heutschi J., Barraud Q., DiGiovanna J., Bartholdi K., Huerlimann M., Friedli L., Vollenweider I., Moraud E. M., Duis S., Dominici N., Micera S., Musienko P. & Courtine G. (2012). Restoring Voluntary Control of Locomotion after Paralyzing Spinal Cord Injury. Science 336, 1182-1185.