New light-activated drugs for the treatment of neuropathic pain

Light can be used to activate drugs in specific areas of the body using photopharmacology. This innovative approach involves changing the chemical structure of a drug by adding light-activated molecular switchsuch as azobenzene. Thus, the compound can only be activated when exposed to light of a certain color, and not in the dark.

Based on these principles, a research group led by the Institute of Bioengineering of Catalonia (IBEC) has developed photoswitchable derivatives of carbamazepine. an antiepileptic drug widely used in medicineto treat certain types of neuropathic pain, such as trigeminal neuralgia.

These drugs, which produce pain-relieving effects when activated by light, are able to suppress nerve signals. on site and on demandThe derivatives synthesized by the researchers are activated at wavelengths corresponding to the color amber, which allows them to pass through tissue and bone using ordinary halogen lamps.

Two synthesized compounds, carbazopine-1 and carbadiazocinexhibit photopharmacological activity, allowing reversible control of hippocampal neuron activity and locomotion using light. danio larvae. These experiments in natural conditions They allow us to observe anxiety-related behavior, which is reflected in sudden swimming movements.

pain-relieving properties

As explained Louise Camerina research fellow at the IBES and the first author of the study: “When we illuminate the larvae that have absorbed these compounds with a certain wavelength, the drug is activated and the larvae move faster. “When the wavelength is changed, its movement slows down again, demonstrating the reversible effect of the compound on the nervous system.”

In addition, carbadiazocin has also demonstrated analgesic properties: “We observed in rat models developed in the laboratory Esther Berrocoso at the University of Cadiz, we have found that carbadiazocin has an analgesic effect in neuropathic pain without any signs of anesthesia, sedation or toxicity. These results allow us to demonstrate a simple and convincing treatment using non-invasive illumination,” he details. Pau GorostizaChief Researcher of IBEC.

Neuropathic pain is caused by injuries or diseases of the somatosensory system, such as lumbar radiculopathy (radiculitis), diabetic neuropathy And chronic postoperative painTreating this type of pain often requires opioids, painkillers that are more effective than common nonsteroidal anti-inflammatory drugs such as paracetamol and ibuprofen.

Reducing side effects

However, its use is controversial due to its inconsistent effectiveness, the need for high doses that can cause tolerance and dependenceand side effects such as constipation, nausea, dizziness and drowsiness. In this context, light therapy is gaining increasing importance in medicine due to its ability to act on certain areas of the bodybecause they increase the effectiveness of treatment and reduce side effects.

The team is already working on the next step planned for this project: activating drugs using infrared light, which penetrates deeper into tissue, and using portable infrared light sources such as lasers or diodes electroluminescent (LEDs).