Scientists ID sunburn 'pain molecule'

London - Researchers at King’s College here say they have identified the exact molecule that causes the stinging pain of sunburn - a finding, Time.com reports, that could lead to improved treatments for more serious conditions, such as arthritis.

The culprit is a protein called CXCL5 that attracts inflammatory immune cells to damaged tissue, which in turn triggers sunburn sting.

To identify the protein, investigators asked healthy participants to expose small areas of their skin to UVB radiation. The exposed patches began to exhibit tenderness after a few hours and hit their pain peak one to two days later. At that point, the research team biopsied the affected skin to look for proteins associated with the pain.

Several of these pain mediators, including CXCL5, were overexpressed. Scientists then used rats to confirm their theory that CXCL5 was the sunburn-pain culprit and found that CXCL5 was overexpressed in sunburned skin in rats as well. They found that when rats were given an antibody that targeted and neutralized CXCL5, the sensitivity to pain was greatly reduced.

Time.com quotes study leader professor Stephen McMahon as saying, “We hope that we have identified a potential target which can be utilized to understand more about pain in other inflammatory conditions like arthritis and cystitis. I’m excited about where these findings could take us in terms of eventually developing a new type of analgesic for people who suffer from chronic pain.”