Fire ants may be unwelcome guests at picnics, but their venom could prove useful in treating the common autoimmune disease psoriasis. Researchers at Emory and Case Western have developed two experimental compounds inspired by the fire ant that appear promising in treating the skin disorder, which causes painful thickening and rashes.
The main toxic ingredients in fire ant venom are called solenopsins. Structurally, these chemicals closely resemble ceramides, which are molecules that help maintain the skin’s barrier against foreign invaders. Ceramides are used in some skin products, but they’re not always beneficial, said Jack Arbiser, a professor at the Emory School of Medicine, in a press release. That’s because they sometimes transform into an inflammatory molecule called sphingosine-1-phosphate (S1P).
So the research team developed two analogs of solenopsin that can’t be converted into S1P. When they tested them in mouse models of psoriasis, they observed that the treated animals had 50% fewer immune cells invading their skin than did the untreated mice. The mice that received the compounds also experienced a 30% drop in skin thickness.
The scientists then examined immune cells and genes from the treated animals. They discovered that genes that normally become more active with conventional treatment like steroids and ultraviolet light actually quieted down when the analogs of solenopsin were administered. And when immune cells in culture were treated with the compounds, they produced more of an anti-inflammatory protein called interleukin 12 (IL-12).
Topical treatments “can soothe the skin in psoriasis, but they are not sufficient for restoration of the barrier. We believe that solenopsin analogs are contributing to full restoration of the barrier function in the skin," said Arbiser in the release. The researchers believe solenopsin analogs may be most useful in combination with existing treatments. The research was published in the journal Scientific Reports.
This is not the first time animal venom has given rise to new ideas in biotech. In June, researchers at National Taiwan University announced they used snake venom to create an antiplatelet drug that may sidestep the bleeding risk seen with aspirin and other blood thinners. Last year, Australian scientists announced they are looking at developing diabetes treatments from venom derived from the platypus and echidna. These animals produce a version of glucagon-like peptide-1 (GLP-1) that may be more stable than what humans naturally make, they believe. AstraZeneca’s Byetta (exenatide) is a GLP-1 agonist that was inspired by gila monster saliva.
As for the derivatives of solenopsin, they still need to be tested to assess their toxicity, Arbiser says. But even if they have the potential to cause systemic poisoning, they may still be able to be used on the skin, he believes. For evidence, he points to one of the most successful poisons ever developed into a pharmaceutical product: botulinum toxin, the main ingredient in the wrinkle-reducing blockbuster Botox.