Sometimes, the unexpected leads to discoveries. A clinical observation has put researchers on the trail of a new treatment for Parkinson’s disease. Injecting bee venom seems to hold back the slow and progressive degeneration of dopaminergic neurons. A study presents the first results of that technique and brings new hope to the fight against this neurodegenerative disorder.
Parkinson’s disease affects over 100,000 people in France each year, according to the association France Parkinson. Today, the most effective medicine is a dopamine agonist called L-Dopa. Recent research offers new therapeutic perspectives. For instance, bee venom injections seem to be able to reduce the symptoms of the disease in mice. But could such a discovery actually help us to treat Parkinson’s disease in humans?
The degeneration of dopaminergic neurons
“In the 80’s, young heroin addicts contracted Parkinson’s disease for no apparent reason,” explains Andreas Hartmann, a neurologist at the Pitié-Salpêtrière Hospital in Paris. This disorder particularly affects dopaminergic neurons that innervate the striatum, a nervous structure responsible for motor function. That is why the recurrent symptom is akinesia, that is, rigidity and tremors while at rest. “In the end, it was shown that a molecule contaminating the heroin, MPTP, was causing the disease.” Today scientists use this molecule to induce the neurodegenerative disorder in laboratory animals.
Bee venom could protect dopaminergic neurons
The idea of using bee venom comes from a clinical observation. “A patient who was a beekeeper, and also affected by Parkinson’s disease, was treated with monthly bee venom injections to become desensitized. The symptoms related to his disease regressed with time. He took fewer medications and felt better. This has intrigued us, and we even started to film the patient to try to understand this phenomenon,” explains Andreas Hartmann. Following this astonishing observation, studies have focused on bee venom and more specifically, on apamin, one of its active components. It regulates certain functions that seem to have a significant impact on the survival of dopaminergic neurons.
Of mice and bees
In order to demonstrate this hypothesis, Andreas Hartmann and his team carried out MPTP injections in mice over a period of 5 weeks to induce Parkinson’s disease. 48 hours after the first injection, the mice were administered either bee venom or apamin. Immediately, a reduction in the degeneration of dopaminergic neurons was observed. However, in some mice, the scientists also observed secondary effects following administration of apamin. Andreas Hartmann explains that “a peptide incorporated in a macromolecule could actually have a different toxicity than this same macromolecule (alone).”
New hope for Parkinson’s patient?
According to Andreas Hartmann, it is important to remain cautious: “We’ve got a cocktail that seems to have satisfying effects, but there is a risk of potentially lethal allergic reactions. In France, more than a dozen people die each year from bee stings.” So, should we intensively study apamin, the active substance in the venom, in order to synthetize it later as a medicine? Or should we analyze the bee venom as a whole and suppress the allergenic substances? “It’s not an easy answer,” confesses Andreas Hartmann. “It’s possible that the allergenic elements contribute to the protection of dopaminergic neurons.”
This discovery is a glimmer of hope in the search for treatments against Parkinson’s disease. Even if many experiments still need to be carried out, the scientists are rather “optimistic”. Behind this unexpected case involving bees, there is real potential taking shape. And it doesn’t stop with Parkinson’s. Some data suggest that apitherapy, bee venom therapy, could have a positive impact on multiple sclerosis. If you thought that killing bees could lead to the end of the world, you might also say that saving them could mean treating, and, thus, saving, humans.
Paper: Plos One