Epidermal Hydration Is Improved by Enhanced Ceramide Metabolism in Aged C57BL/6J Mice After Dietary Supplementation of Royal Jelly

Abstract

Epidermal hydration is maintained by the epidermal lipid barrier, of which ceramide (Cer) is the major constituent. We examined the dietary effect of royal jelly (RJ) on epidermal hydration in aged mice. Altered Cer metabolism was further determined by measuring epidermal levels of individual Cer, glucosylceramide (GC), and sphingomyelin (SM) species, and of Cer-metabolizing enzymes. Aged C57BL/6J mice were fed a control diet (group AGED) or diets with 1% RJ harvested from two different areas (groups AGED+RJ1:AGED + RJ2) for 16 weeks. Aged C57BL/6J mice with no dietary intervention (the control group: group C) represented the onset of aging. In group AGED, epidermal levels of hydration, Cer1/2/5/6/7, GC-A/B/C/D, SM1/2/3, and β-glucocerebrosidase (GCase) protein, an enzyme of GC hydrolysis for Cer generation, were lower than in group C; these levels, as well as those of Cer3/4 and acidic sphingomyelinase (aSMase) protein, an enzyme of SM hydrolysis for Cer generation, were higher in group AGED + RJ1 than in group AGED. Despite increases in GC-B, SM1/2/3, and serine palmitoyltransferase2 protein, an enzyme of de novo Cer synthesis, in group AGED + RJ2 to levels higher than in group AGED, epidermal levels of hydration, Cer1-7, GC-A/C/D, GCase, and aSMase proteins were similar in these two groups. Expression of GCase and aSMase mRNAs, and of Cer synthase3 and ceramidase proteins, enzymes of de novo Cer synthesis and degradation, did not differ among groups. Dietary RJ1 improved epidermal hydration by enhancing Cer metabolism with increased levels of all Cer, GC, and SM species, and of GCase and aSMase proteins.

A topical heparinoid‐containing product improves epidermal permeability barrier homeostasis in mice

“…Although the signalling mechanisms by which the heparinoid‐containing cream improves epidermal function are unclear, upregulation of the expression levels of epidermal mRNA for several key components associated with epidermal function likely accounts for the improvements in epidermal functions. Because of the importance of filaggrin and ceramides in stratum corneum hydration, Hirudoid ® cream‐induced elevations in expression levels of epidermal mRNA for filaggrin and serine palmitoyltransferase (SPT) could contribute to the improvements in stratum corneum hydration. In addition, Hirudoid ® cream increased the expression levels of epidermal mRNA for lipid synthetic enzymes (HMGCoA reductase and SPT), as well as differentiation marker‐related proteins, which could also contribute to the improvements in epidermal permeability barrier function.…”

The consumption of propolis and royal jelly in preventing upper respiratory tract infections and as dietary supplementation in children

“…No other effects of RJ were found in exercise but it was found to be effective on new bone formation and rapid maxillary expansion, which shows its valuable support to the general condition of the body [ 24 ]. Epidermal hydration, maintained by the epidermal lipid barrier, of which ceramide is one of the constituents, has been enhanced by dietary supplementation of RJ in mice [ 25 ]. The effects of RJ and CAPE on aggrecanases in chondrosarcoma cells were investigated to enlighten the molecular basis of these compounds in osteoarthritis [ 26 ].…”