Using computer modeling, researchers have designed a new compound that may help to treat neuropathic pain. In animal trials, it produced immediate, long-lasting therapeutic effects.
Neuropathic pain is a chronic condition wherein people have a heightened sensibility to pain, or hyperalgesia, and feel pain following stimuli that would not usually cause pain, or allodynia. For some individuals, the pain can come and go, seemingly at random. For others, however, it can be continuous. The condition affects up to 10% of the population of the United States, and there are currently no specific treatments that significantly relieve the discomfort and pain.
As it stands, anti-depressants and anti-epileptics are most commonly used to treat neuropathic pain, but less than 50% of people report a significant reduction to their pain. There is a range of conditions and situations that could lead to neuropathic pain. These include diabetes, spinal cord injury, herpes zoster infection, toxins, trauma, and chemotherapy. But although certain risk factors are known, there are still many gaps in our knowledge.
It is thought that peripheral neuropathic pain is caused by lesions in nerves. These lesions disrupt the blood-nerve barrier, allowing blood and the immune cells that it carries to contact the nerves. However, exactly how and why this produces neuropathic pain is not understood. The molecular interactions and chemical pathways involved are still being investigated.
Researchers from the Institute for Neurosciences of Montpellier found that immune cells, which flood the damaged nerves at the site of the lesion, produce a cytokine called FL which binds to activate FLT3 receptors. FLT3 receptors are produced by hematopoietic stem cells, the cell type that gives rise to blood cells.
Once the two molecules lock together, a chain reaction is activated that impacts the sensory system, producing pain and allowing it to persist. This is known as chronification. The findings are published this week in the journal Nature Communications.
Once the team understood the role of FLT3 in generating neuropathic pain, they analyzed 3 million potential molecular configurations eventually finding an anti-FTL3 molecule – which they dubbed BDT001.
When tested on mice, within 3 hours, the new drug reduced symptoms such as hyperalgesia and allodynia. This relief lasted 48 hours following a single dose.
A drug is not considered efficacious unless it is works at least 50% of the time. Of note, the anti-depressants of used for neuropathic pain only relieve depression about a third of the time as well.
On occasion, I use St. John’s Wort, also used as a natural antidepressant, for neuropathic pain. However, my first choice is inositol. Inositol works by opening that blood-nerve barrier noted above, allowing nutrients to heal the nerve. Unlike St. John’s Wort, inositol does not have the drug-herb interactions that limit its’ use. Most patients with neuropathic pain are already on medication that prohibits the use of St. John’s Wort.
The Bottom Line:
This research on the nerve-blood barrier is enlightening, reinforcing my clinical experience with inositol. If you enter “inositol” in the search button at the top of my blog page, you can read previous blogs I have written on this former B vitamin.
Source: National Institutes of Health March 13, 2018