Eudermic Properties and Chemical-Physical Characterization of Honeys of Different Botanical Origin

Background: Honey is a natural product that, thanks to its composition, particularly the high sugar content, is highly appreciated as an energy nourishment. In addition to sugars, it contains many other substances (carbohydrates, free amino acids, enzymatic proteins, organic acids, polyphenols) from which the therapeutic properties of honey arise: hydrating and osmotic activity, antimicrobial action, and antioxidant and anti-inflammatory power. Objectives: The present work aims to deepen our knowledge/understanding of the activity of skin protection exerted by honey, as a synergic result of its multiple therapeutic effects. Moreover, this study wants to find possible correlations between biological properties and the chemical-physical traits of honey. Methods: To carry out this research, five varieties of citrus honey, one of acacia honey, one of chestnut honey, and one of multifloral honey were used. The honeys were first characterized by chemical-physical analysis and then were subjected to qualitative melissopalynological analysis. Tests were also carried out to evaluate both their antioxidant power and the effect on collagenase, an enzyme involved in the degradation of collagen present in the extracellular matrix and, therefore, in the processes of skin aging. Finally, honey samples were then used in in vitro experiments to assess their action in stimulating cell viability and proliferation on human keratinocytes. Results: Chemical-physical analysis demonstrated a good water content (about 17%), an important sugar content (with the monosaccharides glucose and fructose being the most represented in all the honey samples), various amino acids (with proline remarkably being the highest in all honeys), and a high concentration of polyphenols and total flavonoids (the maximum in chestnut honey, 762 mg/kg and 514 mg/kg, respectively). Conclusions The results obtained in this work confirm the ethnopharmacological use of honey in wound care, bring new scientific knowledge on the use of honey in dermatology, and highlight two fields of excellence, particularly incitrus and chestnut honey.