Efficacy of the continuous use of a lotion with carbon dioxide on male subjects with mild acne.

OBJECTIVE: Acne vulgaris is caused by dyslipidemia, dyskeratosis and/or abnormal bacterial growth. The obstruction of skin pores due to hyperkeratosis of the infundibulum contributes to the formation of comedones. Thus, normalizing keratinization of epidermal cells in skin pores might be useful to improve acne. Recently, it has been found that the transcutaneous application of carbon dioxide (CO2 ) regulates imbalances of the desquamatory process. In this study, we evaluated the efficacy of a skin lotion containing CO2 on mild acne. METHODS: Twenty-four healthy Japanese males (20-29 years old) with mild acne attended this evaluation. The subjects were divided into 2 groups, one group used a skin lotion containing CO2 and the other group used a skin lotion without CO2 . Following facial washing, each subject topically applied the skin lotion with or without CO2 twice a day for 4 weeks. Prior to the start of the evaluation (week 0) and following 2 and 4 weeks of treatment, acne symptoms were assessed by a dermatologist and by instrumental measurements. RESULTS: Topical application of the skin lotion with CO2 for 4 weeks significantly improved acne symptoms, which was recognized by the subjects. However, treatment with the skin lotion without CO2 did not improve acne symptoms. This improvement of acne symptoms by CO2 was not accompanied by changes in sebum levels, skin surface pH, skin capacitance, or porphyrin levels. CONCLUSION: The transcutaneous application of a lotion with CO2 improves acne symptoms by normalizing keratinization without affecting skin surface conditions.

Evaluation of subclinical chronic sun damage in the skin via the detection of long-lasting ultraweak photon emission.

BACKGROUND: It is well known that solar radiation accelerates skin photoaging. To evaluate subclinical photodamage in the skin especially from the early phase of ultraviolet (UV)-induced damage, we have focused on ultraweak photon emission (UPE), also called biophotons. Our previous study reported that the amount of long-lasting UPE induced by UV, predominantly from lipid peroxidation, is a valuable indicator to assess cutaneous photodamage even at a suberythemal dose, although it was only applied to evaluate acute UV damage. The aim of this study was to further investigate whether long-lasting UPE could also be a useful marker to assess subclinical chronic sun damage in the course of skin photoaging. MATERIALS AND METHODS: Forty-three Japanese females in their 20s were recruited and were divided into two groups according to their history of sun exposure based on a questionnaire (high- and low-sun-exposure groups). Several skin properties on the cheek and outer forearm were measured in addition to UV-induced UPE. RESULTS: Among the skin properties measured, water content, average skin roughness, and the lateral packing of lipids in the stratum corneum were significantly deteriorated in the high-sun-exposure group as were changes in some skin photoaging scores such as pigmented spots and wrinkles. In addition, those skin properties were correlated with the UPE signals, suggesting the possible impact of oxidative stress on chronic skin damage. CONCLUSION: Subtle oxidative stress detected by long-lasting UPE may contribute to subclinical cutaneous damage at the beginning phase of chronic sun exposure, which potentially enhances skin photoaging over a lifetime.

Efficacy of a moisturizer containing a pseudo-ceramide and a eucalyptus extract for Japanese patients with mild atopic dermatitis in the summer.

BACKGROUND: Skin moisturizing is advocated to take care of the skin of patients with atopic dermatitis (AD). However, many patients stop using moisturizers in the summer because of excessive sweating and high humidity. OBJECTIVES: To examine the efficacy of a moisturizing gel containing a pseudo-ceramide and a eucalyptus extract, which enhances epidermal ceramide synthesis of patients with mild AD in the summer. METHODS: We performed a single-blinded 4-week clinical trial of body care on 44 Japanese subjects who had mild AD. They had not applied any moisturizer on their body in the summer. Twenty-seven subjects used the moisturizing gel containing a pseudo-ceramide and a eucalyptus extract twice a day and the 17 other subjects did not use any moisturizer. Prior to and at the end of weeks 2 and 4, the skin conditions of each subject were evaluated. RESULTS: During the test period, the atmospheric temperature increased and skin dryness and scaling significantly improved with or without application of the moisturizing gel. However, the improvement in dryness of the treated group was significantly higher than that of the nontreated group. Erythema and itchiness were significantly improved only in the treated group. The skin hydration on the forearm increased significantly only in the treated group. Accompanying those improvements, the quality of life of the subjects, evaluated by Skindex-16® , was significantly improved. CONCLUSION: The usage of a moisturizer containing a pseudo-ceramide and a eucalyptus extract is effective for care of the skin of AD subjects even in the summer.

The efficacy of a pseudo-ceramide and eucalyptus extract containing lotion on dry scalp skin.

OBJECTIVE: Dry and scaly conditions on the scalp are often observed in patients with atopic dermatitis, seborrheic dermatitis and/or pityriasis capitis. Those scalp lesions often exhibit low barrier function and reduced ceramide levels. Therefore, a clinical study was conducted to evaluate the efficacy of topical application of a pseudo-ceramide and eucalyptus extract-containing lotion on the scalps of patients with skin diseases. METHODS: Thirty-four subjects participated in this study (atopic dermatitis: 19 subjects; seborrheic dermatitis: 6 subjects; pityriasis capitis: 9 subjects). After 4 weeks of daily treatment with a pseudo-ceramide and eucalyptus extract-containing lotion, the skin symptoms had significantly improved in all patients with those skin diseases. RESULTS: Skin dryness, scaling, and erythema were significantly improved by treatment with the lotion. The moisture-retention ability of the scalp was significantly increased and itchiness, evaluated using a visual analog scale, decreased significantly. Accompanying those improvements was a significant improvement in the quality of life of the subjects, evaluated by the Skindex-16®. CONCLUSION: From these results, we conclude that this pseudo-ceramide and eucalyptus extract-containing lotion effectively improved the dry and scaly conditions of the scalp as well as the quality of life of subjects with atopic dermatitis, seborrheic dermatitis, or pityriasis capitis.

A cleanser based on sodium laureth carboxylate and alkyl carboxylates washes facial sebum well but does not induce dry skin.

BACKGROUND: Because excess sebum and/or metabolites of sebum induce skin problems, cleansers that can remove those kinds of sebum are sought after. However, many people, especially who have little facial sebum, are afraid to wash off sebum well because that may induce dry skin. This concern may be caused by the result that cleansers with a high cleansing ability tend to decrease not only facial sebum but also natural moisturizing factors and intercellular lipids that are essential for cutaneous function. Recently, we have developed a new cleanser based on sodium laureth carboxylate and alkyl carboxylates (AEC/soap) that cleans sebum well without penetrating the stratum corneum. OBJECTIVES: This trial was aim to clarify the effects of sebum removal by AEC/soap-based cleanser on the induction of dry skin. METHODS: We designed a controlled single blind parallel trial. Thirty female subjects with mild dry skin were assigned randomly to two groups: one group used AEC/soap-based cleanser while the other group kept using their usual facial cleanser twice a day for 4 weeks in the winter season. RESULTS: Using a colored artificial sebum mixture, it was demonstrated that this cleanser washed sebum well. Following usage of this cleanser, their dry skin improved rather than worsen which was indicated by instrumental analysis and visual assessment. These improvements were recognized by subjects. CONCLUSIONS: These results suggest that AEC/soap-based cleanser washes off facial sebum well, but it has little effect on the induction of dry skin because of less penetration into stratum corneum.

Precipitate deposition around CMC and vesicle-to-micelle transition of monopotassium monododecyl phosphate in water.

Monoalkyl phosphate (MAP) salts are a kind of bivalent anionic surfactants. The difference of properties between half-neutralized monosalt and completely neutralized disalt is very interesting. In this study, the aggregation behavior of monopotassium monododecyl phosphate (MAP-12K) in aqueous solution with an increase in concentration was investigated by surface tension (γ), elemental analysis, gas chromatography, differential scanning calorimetry, steady-state fluorescence, and negative strained transmission electron microscopy techniques. MAP-12K aqueous solution showed some characteristics: (I) Vesicle aggregates were formed at very dilute concentration (1.2 mM). (II) The precipitate of a highly hydrophobic dimer of MAP, which was quaternary neutralized by potassium, was generated only in a certain dilute concentration region (2.7-200 mM) around the critical micelle concentration (cmc = 20 mM). (III) Vesicles spontaneously translate into micelles at the cmc. (IV) In the higher concentration above 200 mM, the solution becomes homogeneous micellar solution. All of these uncommon characteristics are thought to be caused by the generation of the dimer, which is much more hydrophobic than dissolved MAP derivatives, in the complicated chemical equilibria based on the weakly acidic character of MAP. MAP-12K aqueous solution behaves as if it is a binary mixed surfactant solution of hydrophobic dialkyl surfactant and hydrophilic monoalkyl surfactant in spite of a single component solution.

Relationship between microstructure of the skin surface and surface reflection based on geometric optics.

BACKGROUND: The behavior of reflected light in skin affects skin appearance and provides clues as to the internal condition of the skin. Surface topography is one of the central physical factors contributing to surface reflection. OBJECTIVE: We tried to clarify the relationship between microstructure of the skin surface and surface reflection based on geometric optics. METHODS: Microstructures and surface reflections in the left cheeks of adult females were evaluated. Skin topography was acquired measuring replicas using confocal laser microscopy. Surface topography was used to calculate arithmetical mean deviation of the surface (S(a)), and geometric index from gradient of the surface (S(grad)), which is expected to correlate with the directionality of surface reflection (DoSR) based on geometric optics. A surface reflection image was acquired from differently polarized pictures of a face, and the index of surface reflection (I(obs)) was calculated as the average pixel value of the area of shine. Correlations between indices were then evaluated. RESULTS: S(grad) and S(a) showed significant correlation (p<0.01) with I(obs). However, S(grad) showed a higher correlation with the simulated surface reflection from the reflection model than S(a). In addition, S(grad) can explain differences in DoSR for some panelists even in the case of an identical S(a). CONCLUSIONS: The topographic element involved in DoSR was extracted from height mapping. S(grad) reflects the ratio of flat area, offering a more effective indicator than S(a) for distinguishing topographic characteristics with respect to surface reflection.