Zinc gluconate is an agonist of peroxisome proliferator-activated receptor-α in the epidermis.

Peroxisome proliferator-activated receptors-α (PPARs-α) are nuclear receptors with anti-inflammatory properties. Zinc gluconate is efficient in the treatment of several inflammatory dermatoses. The aim of our work was to determine whether the modulation of PPAR-α expression and activity could be one of the mechanisms of action of zinc gluconate anti-inflammatory activity in inflammatory dermatoses. Thus, we used ex vivo skin explants incubated with lipopolysaccharide (LPS), a pro-inflammatory molecule, with or without zinc gluconate. We evaluated PPAR-α protein expression using immunohistochemistry, PPAR-α DNA-binding activity using an ELISA-like technique, and PPAR-α mRNA levels using quantitative PCR. On the one hand, we found that PPAR-α epidermal protein expression was stimulated by LPS and that LPS suppressed PPAR-α mRNA expression, without modifying its function. On the other hand, in inflammatory LPS-stimulated explants, zinc gluconate significantly upregulated PPAR-α function and mRNA expression level, without changing its epidermal protein expression. These results suggest that zinc gluconate may be a PPAR-α agonist, which might play a role in the anti-inflammatory activity of this molecule.

Human ß-defensin-2 and psoriasin, two new innate immunity targets of zinc gluconate.

BACKGROUND: Antimicrobial peptides (AMPs) are a large family of peptides implicated in innate immunity, especially in the epidermis. Zinc gluconate has been proven to be efficient to treat inflammatory dermatoses, such as acne vulgaris. OBJECTIVES: The aim of our work was to determine whether AMPs could be new targets of zinc gluconate treatment in inflammatory dermatoses. MATERIAL AND METHODS: To test this hypothesis, we used an ex vivo lipopolysaccharide (LPS)-induced inflammatory skin explant model, with or without zinc gluconate pretreatment. We evaluated human ß-defensin-2 (hBD-2), human ß-defensin-4 (hBD-4) and psoriasin protein expression and release by immunohistochemistry and ELISA, as well as the mRNA expression level by quantitative PCR. RESULTS: We found that hBD-2 and psoriasin mRNA expression levels and hBD-2 extracellular release, but not hBD-4 expression and release, were significantly upregulated by zinc gluconate in LPS-stimulated inflammatory skin explants. CONCLUSION: These results suggest that hBD-2 and psoriasin may be two main targets of zinc gluconate, involved in its anti-inflammatory activity in dermatoses.