Dietary effect of Lactobacillus plantarum CJLP55 isolated from kimchi on skin pH and its related biomarker levels in adult subjects / 한국영양학회지

PURPOSE: The skin pH is maintained by epidermal lactate, free fatty acids (FFAs), and free amino acids (FAAs). As a significant determinant of skin health, the skin pH is increased (less acidic) under abnormal and aged skin conditions. In a search for dietary alternatives that would promote an acidic skin pH, this study investigated the dietary effects of Lactobacillus plantarum CJLP55 isolated from Korean kimchi on the skin pH, and epidermal levels of lactate, FFAs, and FAAs in adult subjects. METHODS: Seventy eight subjects (mean age 24.9 ± 0.5 years, range 19 ~ 37 years) were assigned randomly to ingest CJLP55, Lactobacillus strain from kimchi, (n = 39, CJLP group) or placebo supplements (n = 39, placebo group) for 12 weeks in a double-blind, placebo-controlled trial. Skin pH and epidermal levels of lactate, FFAs and FFAs were assessed at 0, 6 and 12 weeks. RESULTS: Although significant decreases in skin pH were observed in both the CJLP and placebo groups at 6 weeks, the skin pH was decreased significantly only in the CJLP group at 12 weeks. In parallel, the epidermal level of lactate in the CJLP group was also increased by 25.6% at 12 weeks. On the other hand, the epidermal level of FAAs were not altered in the CJLP and placebo groups, but the epidermal level of total FFAs, including palmitic acid and stearic acid, was lower in the CJLP group than in the placebo group over 12 weeks. The changes in the other FFAs, such as palmitoleic acid and oleic acid, were similar in the CJLP and placebo groups over 12 weeks. CONCLUSION: Overall, a dietary supplement of CJLP55 promotes acidic skin pH with a selective increase in epidermal lactate in adult subjects.

Relation between pH in the Trunk and Face: Truncal pH Can Be Easily Predicted from Facial pH

BACKGROUND: The clinical symptoms of facial and truncal acne differ. Skin surface acidity (pH), which is affected by sebum secretions, reflects the different clinical characteristics of the face and trunk. However, no studies have been conducted on truncal sebum production and skin pH. OBJECTIVE: We evaluated the differences and relationship between pH values of the face and trunk. We also evaluated the relationship between pH and the quantity of sebum produced in the trunk. METHODS: A total of 35 female patients clinically diagnosed with truncal acne were included. We measured pH on the face and truncal area using the Skin-pH-Meter PH 905®. We measured truncal sebum secretions using the Sebumeter SM 815®. Statistical analysis was performed to evaluate the correlations and differences between pH and sebum. RESULTS: Facial pH was significantly higher than chest and back pH values. The correlation between pH on the trunk and the face was significant. We used linear regression equations to estimate truncal pH using only measured pH from the chin. There was no significant relationship between truncal sebum secretion and pH. CONCLUSION: This was the first study that evaluated the differences and correlations between facial and truncal pH. We found that facial pH can predict truncal pH. In addition, we conclude that differences in pH and sebum secretion between the face and trunk are one of the reasons for differences in acne symptom at those sites.

Relation between pH in the Trunk and Face: Truncal pH Can Be Easily Predicted from Facial pH

BACKGROUND: The clinical symptoms of facial and truncal acne differ. Skin surface acidity (pH), which is affected by sebum secretions, reflects the different clinical characteristics of the face and trunk. However, no studies have been conducted on truncal sebum production and skin pH. OBJECTIVE: We evaluated the differences and relationship between pH values of the face and trunk. We also evaluated the relationship between pH and the quantity of sebum produced in the trunk. METHODS: A total of 35 female patients clinically diagnosed with truncal acne were included. We measured pH on the face and truncal area using the Skin-pH-Meter PH 905®. We measured truncal sebum secretions using the Sebumeter SM 815®. Statistical analysis was performed to evaluate the correlations and differences between pH and sebum. RESULTS: Facial pH was significantly higher than chest and back pH values. The correlation between pH on the trunk and the face was significant. We used linear regression equations to estimate truncal pH using only measured pH from the chin. There was no significant relationship between truncal sebum secretion and pH. CONCLUSION: This was the first study that evaluated the differences and correlations between facial and truncal pH. We found that facial pH can predict truncal pH. In addition, we conclude that differences in pH and sebum secretion between the face and trunk are one of the reasons for differences in acne symptom at those sites.

Application of Topical Acids Improves Atopic Dermatitis in Murine Model by Enhancement of Skin Barrier Functions Regardless of the Origin of Acids

BACKGROUND: The acidic pH of the stratum corneum (SC) is important for epidermal permeability barrier homeostasis. Acidification of the skin surface has been suggested as a therapeutic strategy for skin disorders such as atopic dermatitis (AD). OBJECTIVE: We performed an animal study to evaluate the usefulness of acidification of SC for inhibition of AD lesions and to find out if the therapeutic effect of vinegar is attributable to its herbal contents, rather than its acidity. METHODS: Five groups of six oxazolone-treated (Ox)-AD mice were treated for three weeks with creams of different acidity: vehicle cream alone (pH 5.5), neutralized vinegar cream (pH 7.4), pH 5.0 vinegar cream, pH 3.5 vinegar cream, and pH 3.5 hydrogen chloride (HCl) cream. Also, we have compared two groups of Ox-AD mice treated with pH 5.5 vehicle cream or pH 5.5 vinegar cream. RESULTS: Ox-AD mice treated with acidic creams exhibited fewer AD-like lesions, had significantly lower eczema scores, decreased basal by transepidermal water loss (TEWL), and increased SC hydration compared to the groups given only vehicle and neutral cream. There was no significant difference between the acidic vinegar and HCl groups. Between the groups treated with vehicle and pH 5.5 vinegar cream, there was no difference in eczema score, basal TEWL and SC hydration. CONCLUSION: Application of topical acids, regardless of their source materials, inhibits the development of AD lesions by maintenance of skin surface pH and skin barrier function in murine model.

Dietary effect of green tea extract on epidermal levels of skin pH related factors, lactate dehydrogenase protein expression and activity in UV-irradiated hairless mice / 한국영양학회지

PURPOSE: Skin pH, an indicator of skin health, is maintained by various organic factors, which include lactate, free amino acid (FAA), and free fatty acid (FFA). As skin ages or with illness, skin pH becomes less acidic, and functional food has been developed to maintain the acidic pH of skin. In this study, we determined the dietary effect of green tea extract (GTE) on skin pH of photo-aged mice, as measured by epidermal levels of lactate, FAA, and FFA. The protein expression and activity of lactate dehydrogenase (LDH), an enzyme of pyruvate reduction for lactate generation, was further determined. METHODS: Albino hairless mice were fed a control diet (group UV+) or a diet with 1% GTE (group GTE) in parallel with UV irradiation for 10 weeks. A normal control group was fed a control diet without UV irradiation for 10 weeks (group UV-). RESULTS: Skin pH was higher (less acidic) in group UV+ than in group UV-. In parallel, epidermal levels of lactate and FFA, as well as of LDH protein expression and activity, were reduced in group UV+. Dietary supplementation of GTE (group GTE) reduced skin pH to similar to the level of group UV-, and inversely increased epidermal levels of lactate, LDH protein expression and activity, but not of FFA. Although epidermal levels of FAA were similar in groups UV- and UV+, it was increased in group GTE to a level higher than in group UV-. In further analysis of major FFA, epidermal levels of palmitic acid [16:0], oleic acid [18:1(n-9)], and linoleic acid [18:2(n-6), but not of stearic acid [18:0] in group GTE were similar to or lower than those in group UV+. CONCLUSION: Dietary GTE normalized skin pH with increased levels of lactate and FAA, as well as with increased protein expression and activity of LDH in the epidermis of UVB irradiated hairless mice.

The Correlation Analysis of Fluid Intake, Skin Hydration and Skin pH of College Students

PURPOSE: The purpose of this study was to verify the correlation analysis between fluid intake on skin hydration and pH of college students. METHODS: The subjects were 129 female nursing students in D city. Data were collected by a self-administered questionnaire, using a skin moisture checker and skin pH meter on faces, hands, and feet. The collected data were analyzed by descriptive statistics, t-test, ANOVA, and Pearson correlation analysis, using SPSS WIN, 20. RESULTS: The daily fluid intake was composed of 57% pure water, 21% caffeinated beverages, 22% non-caffeinated beverages. There were significant differences in average skin hydration on the three body parts according to pure water, caffeinated beverages, and non-caffeinated beverages; however, there was no significant difference measured by fluid intake. There was a significant positive correlation between fluid intake and skin hydration: between pure water and skin hydration. There was significant negative correlation between caffeinated beverages and skin hydration: between non-caffeinated beverages and skin hydration. CONCLUSION: The results suggest that fluid intake, pure water, caffeinated beverages, and non-caffeinated beverages have an effect on skin hydration and pH. Therefore, it is good to increase the amount of fluid intake but, it is recommended to increase the amount of intake of pure water rather than beverages to improve skin status.

Dermatologic Effects and Management of Urine and Feces on Infant and Adult Skin.

The effect of urine and feces on the skin is a contributing factor to the development of incontinent and diaper dermatitis. The objective of this research was to evaluate skin effects of a given urine or fecal sample on the donor child and/or an adult caregiver, both of whom would be exposed to the biological material in course of daily life. Methods: Urine was evaluated under a variety of experimental skin conditions: normal (N), compromised by tape stripping (C), hydrated by prolonged exposure to water via occlusive patch (H), and hydrated/compromised (H/C). After pre-treatment, sites were patched (3 times of 24-h each) with 0.5 ml infant urine, saline (negative control) or 0.3% sodium lauryl sulfate (SLS, positive control). Fecal material was evaluated using a 4-h patch followed by tape stripping of selected sites. Results: In the urine study, a single 24-h patch produced a significant elevation of pH compared to both the negative (saline) and positive (sodium lauryl sulfate) controls for all experimental skin conditions. Erythema produced by urine was intermediate between the negative and positive controls, and significantly different from the negative control on the N and C skin test sites. All three materials produced an increase in hydration of the skin. The single 4-h patch of fecal material produced significant erythema, a significant elevation of pH, and a significant increase in TEWL. Recovery to pre-treatment levels was observed by the next day on sites that received no further treatment. However, on sites patched with fecal material, then further compromised by tape stripping, recovery to pre-treatment levels for erythema and TEWL were delayed. Conclusion: These studies indicate that urine appears to have an inherent low level irritant property when in continuous contact with skin for 24 to 48 hours. With relatively short exposures of 4 hours fecal material causes visible erythema, increases in pH and TEWL, and decreases in stratum corneum resilience to the subsequent insult of tape stripping. Results re-inforce the utility of modern diapers and incontinent products, utilizing superabsorbent materials, to effectively absorb wetness, keeping skin dryer and minimizing adverse skin effects.

Effects of Alcohol Intake on the Skin Physiology / 대한피부과학회지

BACKGROUND: Alcohol intake induces complex changes in the human body. However, there has not been much investigation on the interaction between alcohol and human skin. OBJECTIVE: The aim of this study is to investigate the effects of alcohol intake on the skin's physiology. METHODS: A total 16 Korean males was enrolled in this study and they were divided into two groups (group A and group B). Each group included 8 people. Group A drank alcohol (20.1%, 360 ml) for 90 min and Group B drank 360 ml of normal saline. The body temperature, the skin erythema index, the transepidermal water loss (TEWL), the skin hydration, the skin pH and skin sebum were measured before and 30 min and 120 min after alcohol intake. RESULTS: In group A, the skin erythema index, TEWL, skin hydration and skin pH significantly increased 30 min after alcohol intake, while the body temperature and sebum decreased. All the measurements except sebum recovered 120 min after alcohol intake. However, in group B, all the measurements were not significantly changed. CONCLUSION: Alcohol intake affects thermoregulation, the skin barrier function and the skin pH. This study showing that physiologic changes are induced by alcohol intake may help investigate the interaction between alcohol and skin disease.

An Update of the Defensive Barrier Function of Skin

Skin, as the outermost organ in the human body, continuously confronts the external environment and serves as a primary defense system. The protective functions of skin include UV-protection, anti-oxidant and antimicrobial functions. In addition to these protections, skin also acts as a sensory organ and the primary regulator of body temperature. Within these important functions, the epidermal permeability barrier, which controls the transcutaneous movement of water and other electrolytes, is probably the most important. This permeability barrier resides in the stratum corneum, a resilient layer composed of corneocytes and stratum corneum intercellular lipids. Since the first realization of the structural and biochemical diversities involved in the stratum corneum, a tremendous amount of work has been performed to elucidate its roles and functions in the skin, and in humans in general. The perturbation of the epidermal permeability barrier, previously speculated to be just a symptom involved in skin diseases, is currently considered to be a primary pathophysiologic factor for many skin diseases. In addition, much of the evidence provides support for the idea that various protective functions in the skin are closely related or even co-regulated. In this review, the recent achievements of skin researchers focusing on the functions of the epidermal permeability barrier and their importance in skin disease, such as atopic dermatitis and psoriasis, are introduced.

An Update of the Defensive Barrier Function of Skin

Skin, as the outermost organ in the human body, continuously confronts the external environment and serves as a primary defense system. The protective functions of skin include UV-protection, anti-oxidant and antimicrobial functions. In addition to these protections, skin also acts as a sensory organ and the primary regulator of body temperature. Within these important functions, the epidermal permeability barrier, which controls the transcutaneous movement of water and other electrolytes, is probably the most important. This permeability barrier resides in the stratum corneum, a resilient layer composed of corneocytes and stratum corneum intercellular lipids. Since the first realization of the structural and biochemical diversities involved in the stratum corneum, a tremendous amount of work has been performed to elucidate its roles and functions in the skin, and in humans in general. The perturbation of the epidermal permeability barrier, previously speculated to be just a symptom involved in skin diseases, is currently considered to be a primary pathophysiologic factor for many skin diseases. In addition, much of the evidence provides support for the idea that various protective functions in the skin are closely related or even co-regulated. In this review, the recent achievements of skin researchers focusing on the functions of the epidermal permeability barrier and their importance in skin disease, such as atopic dermatitis and psoriasis, are introduced.