Some bile acids may help to improve or prevent the skin inflammation associated with psoriasis, according to the results of a study published in the Journal of Investigative Dermatology.
Researchers at University of California Davis Health said the study suggests bile acids may influence inflammation by preventing immune T cells from producing the proinflammatory protein IL-17A and blocking the immune cell movement to the inflammation site. The secondary bile acids studied include lithocholic acid (LCA), deoxycholic acid (DCA) and 3-oxoLCA.
In a press release, Dr. Sam T. Hwang, senior author, said: “Our studies showed that bile acids significantly inhibited skin inflammation without causing apparent systemic adverse effects.” He is professor and chair of dermatology at UC Davis Health.
In earlier work, the researchers determined chemokine receptor 6 (CCR6), and its binding partner CC chemokine ligand 20 (CCL20) are linked to the inflammation caused by psoriasis. CCR6 is a critical agent for the migration of T cells to the injury site, leading to inflammation.
In a mouse model studying IL-23, the researchers determined that LCA (administered either by injection or orally), diminished the production of the proinflammatory protein IL-17A, and prevented skin cells from producing CCL20.
In one study, the researchers injected mice with IL-23 DNA to induce a response that mimicked a psoriasis-like skin disease.
Compared to placebo, the researchers reported that mice treated with any of the three secondary bile acids demonstrated had less redness, scaling and ear thickness. The LCA bile acids showed the greatest improvement in ear swelling.
“Giving bile acids or using treatments that regulate the work of bile acids may be beneficial for controlling psoriatic inflammation,” said Zhenrui Shi, visiting assistant researcher in the UC Davis Department of Dermatology and co-lead author on the study.
“Our work provides an explanation for several prior small pilot studies of oral bile acid supplementation in psoriatic patients that resulted in improvement of their psoriasis.”