As many as 6 million Americans experience the pain and irritation of the skin condition psoriasis, who could now find comfort in the unlikeliest of places.
Scientists have discovered that compounds derived from fire ant venom could take the sting out of this incurable autoimmune disease, leading to hopes of new treatments for the condition.
New research, led by a team from Emory University, has found that solenopsin – the alkaloid that constitutes the chief toxic component in the venom of fire ants (aka the genus Solenopsis) – bears a strong chemical resemblance to lipid molecules called ceramides, which help to protect the skin.
Ceramides maintain the barrier function of our skin by helping the epidermis to retain moisture and repel microorganisms, which is why they're used in a variety of topical skin medications, including ones to treat eczema.
But there's a problem with ceramides – in some circumstances, the molecule can degrade into what's called sphingosine–1-phosphate (S1P), a compound that promotes cell growth but which can also lead to inflammation.
This is where the fire ant venom comes in.
Having observed the molecular similarities between solenopsins and ceramides, dermatologist Jack Arbiser and his team developed two analogues of the venom ingredient that looked like ceramides, but which didn't have the ability to convert into S1P.
To test the analogues, they mixed them into skin creams (with the active molecule making up 1 percent of the cream) and applied them to mice bred to have psoriasis-like skin called KC-Tie2 mice.
After 28 days of treatment, the treated mice showed decreases in skin thickness (about 30 percent) when compared with control animals, and also exhibited around 50 percent less immune cells infiltrating the skin – hallmarks of psoriasis that contribute to the condition's build-up of scaly, itchy skin patches.
"We believe that solenopsin analogues are contributing to full restoration of the barrier function in the skin," says Arbiser. "Emollients can soothe the skin in psoriasis, but they are not sufficient for restoration of the barrier."
Mice immune cells in culture also showed promising results after the compound was introduced, seeing decreases in production of an inflammatory signal called IL–22, along with increased production of an anti-inflammatory, IL–12.
The compounds also decreased the activity of some genes that become over-activated by some of the current treatments for psoriasis, such as steroids and ultraviolet light.
"This may be compensatory and a mechanism of resistance to anti-psoriasis therapy," Arbiser says, "and it suggests that the solenopsin compounds could be used in combination with existing approaches."
Of course, there's no guarantee that these kinds of restorative effects would be replicated in trials with human skin, but the researchers are hopeful they might be, and say that future research is warranted.
We're a long way from a cure yet, but it looks like we're getting closer all the time, and for a condition that's thought to affect as many as one in 25 people, that's great news.
Just don't take these findings as a reason to go out and make your own home-fashioned fire ant venom remedy. If you find a stinging horror raft of fire ants floating through your neighbourhood, steer well clear.
Trust us, that's not what a soothing, skin-restoring treatment looks like.
The findings are reported in Scientific Reports.