Tapinarof (GSK2894512, Benvitimod, WBI 1001, DHPS, DMVT 505) is a natural agonist of aryl hydrocarbon receptor (AhR) and induces nuclear translocation of AhR in immortalized keratinocytes (HaCaT) with EC50 of 0.16 nM. Tapinarof induces cellular apoptosis in CD4+ T cells in a dosedependent manner with IC50 of 5.2 μM.
Tapinarof binds and activates AhR in multiple cell types, including cells of the target tissue –human skin. In addition, tapinarof moderates proinflammatory cytokine expression in stimulated peripheral blood CD4+ T cells and ex vivo human skin, and impacts barrier gene expression in primary human keratinocytes; both of these processes are likely to be downstream of AhR activation based on current evidence.[1]
The anti-inflammatory properties of tapinarof derive from AhR agonism is conclusively demonstrated using the mouse model of imiquimod-induced psoriasiform skin lesions. Topical treatment of AhR-sufficient mice with tapinarof leads to compound-driven reductions in erythema, epidermal thickening and tissue cytokine levels. In contrast, tapinarof has no impact on imiquimod-induced skin inflammation in AhR-deficient mice.[1]
[1] Susan H Smith, et al. J Invest Dermatol. 2017 Oct;137(10):2110-2119.