Dietary effect of green tea extract on hydration improvement and metabolism of free amino acid generation in epidermis of UV-irradiated hairless mice / 한국영양학회지

PURPOSE: Ultraviolet (UV) irradiation decreases epidermal hydration, which is maintained by reduction of natural moisturizing factors (NMFs). Among various NMFs, free amino acids (AA) are major constituents generated by filaggrin degradation. This experiment was conducted to determine whether or not dietary supplementation of green tea extract (GTE) in UV-irradiated mice can improve epidermal levels of hydration, filaggrin, free AAs, and peptidylarginine deiminase-3 (PAD3) expression (an enzyme involved in filaggrin degradation). METHODS: Hairless mice were fed a diet of 1% GTE for 10 weeks in parallel with UV irradiation (group UV+1%GTE). As controls, hairless mice were fed a control diet in parallel with (group UV+) or without (group UV-) UV irradiation. RESULTS: In group UV+, epidermal levels of hydration and filaggrin were lower than those in group UV-; these levels increased in group UV+1% GTE to levels similar to group UV-. Epidermal levels of PAD3 and major AAs of NMF, alanine, glycine and serine were similar in groups UV- and UV+, whereas these levels highly increased in group UV+1% GTE. CONCLUSION: Dietary GTE improves epidermal hydration by filaggrin generation and degradation into AAs.

Estudo clínico observacional de eficácia e segurança do uso de extratos de Imperata cylindrica e de Triticum vulgare... / Surveillance clinical trial for efficacy and safety uses of extracts of Imperata cylindrica and Triticum vulgare...

A hidratação cutânea é, sem dúvida alguma, uma das modalidades terapêuticas mais empregadas pelos dermatologistas em sua prática clínica diária. Neste artigo se apresenta o resultado clínico de um estudo fase IV, aberto, multicêntrico, prospectivo, de uso de extratos de Imperata cylindrica e de Triticum vulgare ceramidas vitaminas A, C, E e F silanol (Epidrat® Ultra) em 168 voluntários portadores de xerose cutânea associada a causas específicas (dermatite atópica, psoríase, xerose senil, hanseníase, climatério e senilidade, diabetes mellitus ou hipotireoismo). Após 30 dias de uso do produto houve alívio, médio, de 40,38% dos sinais (p<0,0001) e 37,08% dos sintomas (p<0,0001) de xerose entre os voluntários (redução média da soma dos sinais e sintomas foi de 40,51% p<0,0001). Antes do uso do produto 61,3% dos voluntários possuíam xerose moderada/grave/muito grave, o que involuiu para 23,2% dos mesmos ao final da avaliação (p<0,0001) inversamente, dos 38,7% dos voluntários considerados com xerose ausente/leve no início do estudo, a porcentagem dos mesmos subiu para 76,2% (p<0,0001, para ambos os comportamentos). Segundo os investigadores, o alívio completo/acentuado da xerose notado foi de 57,1% e, para os voluntários, de 60,7% (p<0,0001). Além do mais, o produto apresentou boa tolerabilidade de uso, com incidência reduzida de eventos adversos realmente relacionados ao seu uso (13,8%) que, em última análise, poderia ser da própria evolução clínica adaptativa da terapêutica tópica, talvez, observada com o uso de qualquer produto tópico, cosmecêutico ou farmacológico. Estes dados, portanto, estabelecem Epidrat® Ultra como uma boa opção terapêutica para abordagem de quadros graves de xerose cutânea.

Dietary Effect of Silk Protein Sericin or Fibroin on Plasma and Epidermal Amino Acid Concentration of NC/Nga Mice

Free amino acids in epidermis function as a major component of Natural Moisturizing Factor (NMF), which maintains the optimal level of water in skin even at the low humidity. In fact, the depletion of free amino acids is reported in the epidermis of atopic dermatitis, the skin condition involving dryness. As an effort searching the dietary source for improving the level of water and free amino acid in epidermis, the dietary effects of silk protein, sericin (S) and fibroin (F) on trans epidermal water loss (TEWL), and plasma and epidermal levels of free amino acids were compared in this study. Thirty of male NC/Nga mice, an animal model of atopic dermatitis, were divided into three groups: group CA as an atopic control with control diet, group S: 1% sericin diet and group F: 1% fibroin diet. Ten of male BALB/c mice were served as group C (control group) with control diet. All mice were fed on diet and water ad libitum for 10weeks. Dry skin condition was established in group CA as TEWL was increased (148.7% of group C). In parallel, epidermal level of glutamate, one of major amino acids functioning as NMF, was dramatically decreased and epidermal levels of methionine and alanine were inversely elevated. Dietary supplementation of sericin (group S) reduced TEWL at the similar level with group C and increased epidermal levels of glutamate as well as serine and glycine, the other major amino acids as NMF. Despite a marked decrease of methionine and alanine, the reduction of TEWL and epidermal levels of glutamate, serine and glycine of group F were less than of group S. Furthermore, in contrast to similar levels of other free amino acids in plasma and epidermis of group S and group C, plasma and epidermal levels of other free amino acids, specifically phenylalanine, isoleucine, cysteine and tyrosine in epidermis of group F, were significantly higher than of group C. Together, our data demonstrate that dietary supplementation of sericin is more effective at improving dry skin condition that paralleled with the normalization of free amino acids in plasma and epidermis of NC/Nga mice.

Effects of Lactic Acid and Sodium Pyrrolidone Carboxylic Acid on the Irritated Skin Reaction Induced by Sodium Lauryl Sulphate Patch Testing of Normal Persons and Atopic Dermatitis Patients / 대한피부과학회지

BACKGROUND: Natural moisturizing factors such as sodium pyrrolidone carboxylic acid and lactic acid may play an important role in increasing the moisture retention of isolated stratum corneum and reducing the incidence of dry and flaky skin in vivo. Although the precise mechanism of surfactant irritancy is not fully understood, it has been suggested that barrier dysfunction of stratum corneum by surfactants results in skin changes such as scaling, erythema, and even fissuring. OBJECTIVE: We evaluated the effect of sodium pyrrolidone carboxylic acid(NaPCA) and lactic acid(LA) with several non-invasive measuring methods in the irritated skin reaction induced by sodium lauryl sulphate (SLS) in normal persons and atopic dermatitis patients. METHODS: After skin irritation for 24 hours with patch test of 1% SLS on five volar sites of right forearm, we applied nothing(A), 3% LA+3% NaPCA(B), 3% LA(C), 3% NaPCA(D), and vehi cle(E) twice a day respectively. Visual score, transepidermal water loss(TEWL), water holding capa city(WHC), and erythema index were measured at 30 min, 24hr, 48hr and 72hr after patch removal. RESULTS: 1. After 72hr, the visual scores of B and C were significantly lower than that of A(control) in atopic dermatitis patients, and that of C in normal persons was significantly lower than that of A, D, and E. 2. TEWL values of B and C in both the normal (after 72hr) and atopic dermatitis group (after 48hr and 72hr) were significantly lower than that of A. 3. WHC values of B, C, D in both the normal and atopic dermatitis group were significantly higher than that of A after 48hr and 72hr. 4. After 72hr, erythema indices by Mexameter of B, C, and D in both the normal and atopic dermatitis group were significantly lower than that of A and values of C were significantly lower than that of E. In the atopic dermatitis group, values of D were also significantly lower than that of E. 5. The mean visual score was significantly correlated with TEWL value and erythema index of Mexameter (r=0.58, r=0.64) and the TEWL value was significantly correlated with erythema index of Mexameter (r=0.64). CONCLUSION: These results suggest that topical application of a moisturizing factor might improve the surfactant-induced disruption of permeability barrier with improvement of the water holding capacity of the stratum corneum.