• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.3
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• pp.389-396
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• 2013

Epidermal hydration is mainly maintained by natural moisturizing factors (NMFs). Of these various NMFs, free amino acids (AAs) are major constituents generated by filaggrin degradation. The reduction of these AAs has been reported in aging skin induced during menopause. In this study, we examined whether the dietary supplementation of royal jelly (RJ) during the pre- and post-menopausal period alters epidermal levels of filaggrins, free AAs, and peptidylarginine deiminase-3 (PAD-3) (an enzyme involved in filaggrin degradation processes). Sprague Dawley rats were divided into five groups: groups fed a control diet for 12 weeks, in which an ovariectomy (OVX) or sham operation (SHAM) were underwent at week 4; groups fed a diet with 1% RJ harvested in different area of Korea (RJ1 and RJ2); and a group fed a diet with isoflavone (IF), the typical functional food for menopause prevention, for 4 weeks before and 8 weeks after an ovariectomy operation. In the epidermis of group OVX, total filaggrins (including profilaggrin and filaggrin) were reduced; these levels in groups RJ1 and IF were similar or less than in group OVX. However, total AAs, which showed no apparent difference between groups SHAM and OVX, were highly increased in groups RJ1 and IF. Specifically, aspartate (Asp) and proline (Pro), the major AAs in functioning NMF, were highly increased in group RJ1. Although total filaggrins, profilaggrin, filaggrin and PAD3 increased, total AAs (including Asp and Pro) in group RJ2 were modest or less than in group RJ1. The PAD3 alteration was not apparent among the four other groups. Taken together, we demonstrate that the diet supplementation of RJ1 enhanced filaggrin degradation (but not through the increased protein expression of PAD3), and increased total AAs, Asp and Pro. RJ1 could be a dietary supplementation for preventing the skin aging induced during menopause.

• Journal of Nutrition and Health
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• v.46 no.2
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• pp.109-118
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• 2013

Ultraviolet (UV) irradiation reduces epidermal hydration, which is paralleled by the reduction of natural moisturizing factors (NMFs). Of various NMFs, free amino acids (AAs) are major constituents generated by filaggrin degradation. In this study, we attempted to determine whether dietary supplementation of royal jelly (RJ) in UV-irradiated mice can alters epidermal levels of hydration, filaggrins, and free AAs as well as of peptidylarginine deiminase-3 (PAD3), an enzyme involved in filaggrin degradation processes. Albino hairless mice were fed either a control diet (group UV+: UV irradiated control) or diets with 1% RJ harvested from different areas in Korea (groups RJ1, RJ2, and RJ3) or imported from China (group RJ4) for six weeks in parallel with UV irradiation. A normal control group (group UV-) was fed a control diet without UV irradiation for six weeks. Reduced epidermal levels of hydration, total filaggrins, and PAD3 were observed in group UV+; in group RJ1, these levels were increased to a level similar to that of group UV-. In addition, profilaggrins, two repeat intermediates (2RI), a precursor with two filaggrin repeats, and filaggrin were increased. Although no alteration of AAs was observed in any of the groups, and glutamate and serine, major AAs of NMF in group RJ1 were higher than in group UV+. Despite the increased levels of PAD3, epidermal levels of hydration, filaggrins, glutamate, and serine in groups RJ2, RJ3, and RJ4 were similar to those in group UV+. Dietary supplementation of RJ1 improves epidermal hydration in parallel with enhanced expression and degradation of filaggrin, but not by increased protein expression of PAD3, along with increased generation of glutamate and serine.