Related Experiment Video
Updated: Jun 4, 2026

Murine Model of Epicutaneously-Induced Immunomodulation
Published on: June 24, 2025
Topical azithromycin and clarithromycin inhibit acute and chronic skin inflammation in sensitized mice, with apparent
Vanesa Ivetić Tkalčević1, Snježana Cužić, Miroslava Dominis Kramarić
1Galapagos istraživački centar d.o.o., Prilaz baruna Filipovia 29, 10000, Zagreb, Croatia. Vanesa.IveticTkalcevic@glpg.com
Abstract:
Macrolide antibiotics inhibit the secretion of Th1 cytokines while their effects on the release of Th2 cytokines are variable. We investigated molecular and cellular markers of Th1- and Th2-mediated inflammatory mechanisms and the anti-inflammatory activity of azithromycin and clarithromycin in phorbol 12-myristate 13-acetate (PMA) and oxazolone (OXA)-induced skin inflammation. Dexamethasone (50 μg/ear), azithromycin, and clarithromycin (500 μg/ear) reduced TNF-α and interleukin (IL)-1β concentration in ear tissue by inhibiting inflammatory cell accumulation in PMA-induced inflammation. In OXA-induced early delayed-type hypersensitivity (DTH), the macrolides (2 mg/ear) and dexamethasone (25 μg/ear) reduced ear tissue inflammatory cell infiltration and secretion of IL-4 while clarithromycin also decreased IFN-γ concentration. Macrolides showed better activity when administered after the challenge. In OXA-induced chronic DTH, azithromycin (1 mg/ear) reduced the number of ear tissue mast cells and decreased the concentration of IL-4 in ear tissue and of immunoglobulin (Ig)E in serum. Clarithromycin (1 mg/ear) reduced serum IgE concentration, possibly by a mechanism independent of IL-4, while both macrolides attenuated mast cell degranulation. In conclusion, azithromycin and clarithromycin attenuate pro-inflammatory cytokine production and leukocyte infiltration during innate immune reactions, while selectively affecting Th2 rather than Th1 immunity in DTH reactions.
Related Concept Videos
Hypersensitivities
Types of Hypersensitivities
Hypersensitivity reactions are categorized into four types: Type 1, Type 2, Type 3, and Type 4. Each type has a distinct mechanism...
Hypersensitivity Reactions: Delayed Hypersensitivity Reactions
Antiasthma Drugs: Leukotriene Modifiers
Leukotriene modifiers work through two distinct mechanisms:
Allergic Drug Reactions
Allergic Reactions: Anaphylaxis
Acne Infection

