Fig. 6.

Topical application of i⁶A and benzyl⁶A reduced the inflammatory response to TPA treatment, on Car-S mice ears. (A) Photograph of one of the 8 Car-S mice pretreated twice on the right ear with i⁶A (in 95% ethanol) before a single treatment with TPA. The right ear appeared normal 24 h after TPA application, whereas the left ear, pretreated only with vehicle (ethanol) before TPA, showed a typical inflammatory status, characterized by evident redness and tissue thickening. (B) Hematoxylin-eosin staining of tissue slices from left ears (pretreated with ethanol alone before TPA) reveals massive infiltration of inflammatory cells in the dermal layer and tissue edema. (C, D) Stained tissue slices from right ears of mice pretreated with i⁶A (C) or benzyl⁶A (D) show a less severe inflammatory status caused by TPA application. (E) The number of infiltrating inflammatory cells, after TPA treatment, in i⁶A- and benzyl⁶A-pretreated ears was significantly lower than in vehicle-pretreated ears. *** P < 0.0001. (F, G and H) Immunohistochemical staining with anti-Ly-6G IgG showed that the infiltrating cells, in vehicle-, i⁶A- and benzyl⁶A-pretreated ears, respectively, were neutrophils. Scale bar: 50 µm.