Drugs targeting the metabotropic glutamate (mGlu) receptors, which are involved in pain transmission, are thought to be promising treatments for pain. However, their systemic use may be limited by significant side effects such as cognitive impairment and hepatotoxicity.
In a paper published in eLife
(online, 11 April 2017), researchers explored the use of a light-activated form of a candidate mGlu5 receptor modulator in mice.
Study results showed that the administration of the inactive form of the drug resulted in significant analgesia when activated by light either at the site of pain or in the thalamus, a key region of the brain involved in pain response.
The researchers say their results show that light activation of systemically inactive drugs could be a powerful strategy for pain control, but there are still several obstacles that must be overcome to transfer it to the clinical setting, such as assessment of the stability and toxicity of photoactive compounds.