- Fire ant venom can reduce skin thickening and inflammation in a mouse model of psoriasis.
- The toxin, Solenopsins resemble ceramides which help protect the skin from infections.
- Solenopsin analogs which were developed reduced skin thickness and inflammatory cells.
The venom of fire ants is found to contain compounds that reduce skin thickening and inflammation in a mouse model of psoriasis.
The findings of the recent study which found the association could lead to new treatments for psoriasis, a common autoimmune skin disease. Though steroids which are applied topically are now most frequently used for mild to moderate psoriasis, they have side effects such as skin thinning and easy bruising.
Toxin In Fire Ant Venom
Solenopsins are a group of toxins in the fire ant venom. They chemically resemble ceramides, which are lipid-like molecules essential for maintaining for the barrier function of the skin. Ceramides can be found in many skin care products.
Under certain conditions ceramides can be converted by cells into S1P (sphingosine-1-phosphate), an inflammatory molecule, says lead author Jack Arbiser, MD, PhD, professor of dermatology at Emory University School of Medicine.
Solenopsin Analogs Help Fight Psoriasis
Two solenopsin analogs that look like ceramides, but can't be degraded into S1P were devised by Arbiser and his colleagues. It was then tested in a mouse model of psoriasis, applying the compounds in a one percent skin cream for 28 days.
The mice treated with solenopsin analogs displayed decreases in skin thickness (about 30 percent) and had fewer (around 50 percent less) immune cells infiltrating the skin compared to the controls. When applied to immune cells in culture, the compounds decreased the cells' production of the inflammatory signal IL-22 and increased production of anti-inflammatory IL-12.
"We believe that solenopsin analogs are contributing to full restoration of the barrier function in the skin," Arbiser says. "Emollients can soothe the skin in psoriasis, but they are not sufficient for restoration of the barrier."
Changes At The Genetic Level
The scientists also looked at how patterns of gene activity were changed in the skins of the mice after treatment. Solenopsin analog application turned down genes that are turned up by current treatments such as steroids and ultraviolet light.
"This may be compensatory and a mechanism of resistance to anti-psoriasis therapy, and it suggests that the solenopsin compounds could be used in combination with existing approaches," Arbiser says.
Citing the example of external application of botulinum toxin, Arbiser says systemic toxicity for the solenopsin derivatives has not been tested, but systemic toxicity would not necessarily preclude use in skin diseases.
- Arbiser et al., Fire ant venom compounds may lead to skin treatments, Scientific Reports (2017)