A double-blind and controlled study on the influence of the vehicle on the skin susceptibility to stinging from lactic acid

Synopsis For patients with skin diseases, the process of treating the skin with topical medications adds to the burden of having the disease. Inconvenient skin reactions can make the treatment troublesome and lower the compliance. Moreover, epidemiological surveys indicate that 50% or more of female consumers believe they have sensitive skin. In the present study, the influence of the vehicle on the adverse skin reaction to lactic acid was judged by the test subjects after application of the test formulations to the facial skin. The results showed a water-in-oil (w/o) emulsion to induce less stinging than an ordinary oil-in-water (o/w) emulsion. Increasing the mineral oil content in the o/w emulsion from 10% to 50% tended (P = 0.077) to decrease the stinging potential of the formulation. An o/w emulsion free from lactic acid but with pH adjusted to 3 using hydrochloric acid induced significantly less stinging than the corresponding lactic acid formulation at pH 3. In conclusion, the present study gives new insights into the influence of vehicle on the stinging capacity of lactic acid, which may be related to its possible penetration via appendages. Hence, encapsulation of the stinging substances in the inner water phase of an emulsion may be a possible option to reduce adverse skin reactions and to increase compliance to water-soluble substances.     

An optimized method for intensive screening of molecules that stimulate beta-defensin 2 or 3 (hBD2 or hBD3) expression in cultured normal human keratinocytes

Normal human skin controls the intrusion of microorganisms by the production of peptide antibiotics such as defensins. The aim of our study was to develop a culture model of normal human keratinocytes for optimal beta-defensin mRNA detection which allows the screening of molecules able to stimulate hBD2 and hBD3 without inducing pro-inflammatory cytokines. A keratinocyte culture model in 96-well plates, in high calcium medium (1.7 mm) allowed to analyze hBD2 and hBD3 mRNA expression in basal condition and after cell stimulation by products from diverse vegetal extracts. The release of IL-8 and the chemokine MIP-3alpha was also evaluated in cell supernatants by ELISA. Among the 184 extracts tested, 75 showed a stimulatory effect on beta-defensin expression: 40 on hBD2, 26 on hBD3 and nine on both defensins. Fifteen of these substances which also induced the release of pro-inflammatory cytokines were eliminated. Among the other substances, four were selected and were analyzed in a dose-dependent study (n = 4) by real-time quantitative RT-PCR and completed by a measure of MIP-3alpha, IL-8 and IL-1alpha levels. These data underline the important necessity of screening result controls by a quantitative method reproduced at least three times. This new method of intensive screening allowed us to exhibit vegetal extracts that were able to stimulate epidermal beta-defensin expression without inducing an up-secretion of pro-inflammatory cytokines.     

Transdermal delivery of two antioxidants from different cosmetic formulations

The efficacy of any cosmetic product containing a functional ingredient is determined by the skin delivery of the active molecule, which is influenced by the type of the vehicle and the molecule itself. This study was designed to compare the percutaneous absorption habits of the antioxidants carcinine and lipoic acid out of various formulations by means of the porcine skin model. Initial evaluation of the in vitro porcine skin model has demonstrated its feasibility for various substances and formulations [1, 2]. Increasing legal requirements for risk assessment in the cosmetic industry have led to the development of this alternative test method. The penetration properties are determined by the OECD Guideline TG 428: Skin Absorption: in vitro Method [3, 4], which allows the use of porcine skin for penetration studies. Porcine skin is used because of its similarity to human skin in terms of its morphology and the essential permeation characteristics [5]. The mass balances for each tested formulation type of the antioxidants show individual penetration behaviours with significant differences. The presented data plainly demonstrate that the lipophilic lipoic acid has a distinct higher penetration potential than the hydrophilic carcinine. The chosen vehicle can enhance or reduce the transdermal delivery of both tested antioxidants. Modern effective cosmetic formulations will work only, if the active ingredients penetrate into the epidermis. In conclusion, the correct selection of a suitable formulation plays an important role during product development.     

基于电子鼻与GC-MS分析精氨酸-葡萄糖美拉德反应体系挥发性风味成分的差异性

为研究不同反应时间对精氨酸-葡萄糖美拉德反应体系挥发性风味物质的影响,利用电子鼻与气相色谱-质谱联用(gas chromatography-mass spectrometry,GC-MS),结合主成分分析(principal component analysis,PCA)和线性判别分析(linear discriminant analysis,LDA),对不同反应时间精氨酸-葡萄糖美拉德反应体系的挥发性风味成分进行差异性分析。结果显示:PCA和LDA均能够较好地区分30 d和40 d的样品,但对于其它样品PCA区分效果要比LDA好。GC-MS从精氨酸-葡萄糖美拉德反应体系中共检测出50种挥发性物质,可分为醇类、醛类、酮类、酯类、烷烃类和其它类化合物等6类物质,其中酯类物质为10、20 d样品中的主要挥发性物质,醇类物质是20 d和30 d样品中的主要挥发性成分,不同反应时间主要挥发性成分差异显著。对不同精氨酸-葡萄糖美拉德反应体系样品挥发性物质进行主成分分析,建立其品质评价模型,得出不同时间的综合得分顺序依次为20、10、60、40、30 d和50 d。     

In vitro antifungal activity of several antimicrobial compounds against Penicillium expansum

Fungicides used in the prevention and control of mold rots in stored apples are subjected to legal, social, and biological limitations. The aim of this study was to find an alternative to postharvest fungicides currently used in the prevention and control of blue mold rot caused by Penicillium expansum in apples. For this purpose, the antimicrobial activity and MIC of several substances against P. expansum were evaluated in vitro using different end point methods: agar diffusion assay, volatility method, and agar dilution and broth dilution MIC assays. Most of the substances tested are common food ingredients and have a recognized antimicrobial activity. Essential oils, such as thymol, eugenol, citral and cineole, vanillin, sodium hypochlorite, acetic acid, potassium sorbate, and hydrogen peroxide, were the substances evaluated. Thymol and citral were the essential oil components that showed the greatest inhibitory effects. The effectiveness of 5 and 10% hydrogen peroxide in growth inhibition of P. expansum in the agar diffusion assay was total, and its MIC as determined by the agar and broth dilution assays was less than 0.025%. These results indicate that the application of small quantities of hydrogen peroxide to the apple skin might be an alternative to fungicides in the elimination of P. expansum.     

Safety evaluation of gums and thickeners used in cosmetic formulations

Safety tests have been carried out on gums and thickeners, continuing a study involving commonly used cosmetic ingredients (1, 2, 3, 4). The ocular and cutaneous tolerance tests have been conducted on the rabbit following the official French methods (5, 6) but with some complements or modifications (1, 2, 3, 4, 7). The test substances (listed in Table 1) were products from various suppliers and of different types and grades. None of the fifty samples tested provoked pathological lesions of the ocular mucous membrane; nevertheless, corneal irritation was noted with silicates, silica and bentonite, probably due to mechanical effect, when applied at relatively high concentration. The highest score on the primary cutaneous irritancy test (moderately irritant) was that for the gelled volatile hydrocarbon solvents. The repeated application test was continued for 6 weeks: no significant pathological reaction was observed. Only a slight intolerance was noted with the gels of volatile hydrocarbons and isopropyl myristate, but the irritant reactions were significantly reduced compared to those previously observed with the pure oils (1, 2). Consequently, based on these data, it can be concluded that the use of gums and thickeners involved in this publication presents no hazard for the skin.
Evaluation toxicologique d'agents gélifiants et épaississants utilisés en cosmetologie     

Topical application of Bifidobacterium-fermented soy milk extract containing genistein and daidzein improves rheological and physiological properties of skin

Application of drug substances to the skin for systemic absorption or action in a particular layer of the skin is a rather old approach. However, over the last years it has received much more attention, as a consequence of the development of new membrane-moderated and matrix reservoir devices. As new reservoir systems, solid lipid nanoparticles (SLN™) and nanostructured lipid carriers (NLC™) have been successfully tested for dermal application of different physicochemical substances. The knowledge obtained from rheological investigations of these systems may be highly useful for the characterization of the newly developed topical formulation. In the present study, an oscillation frequency sweep test was used for the evaluation of storage modulus (G_), loss modulus (G_), and complex viscosity (_*) of 12 different SLN and NLC formulations, over a frequency range from 0 to 10 Hz. The lipidic aqueous dispersions were prepared using three different solid lipids (Softisan_138, Compritol_888 and stearyl alcohol) as matrix material. Miglyol_812, tocopherol, sunflower oil and long-chain triacylglycerols were the chosen liquid lipids for NLC preparation. The objective of the present work was to investigate the effect of these different liquid lipids on the rheological properties of aqueous dispersions of NLC as model systems. It was found that the liquid oil component of the formulation has a strong influence on the viscoelastic parameters, which are dependent on the particle size, zeta potential and crystallinity of the lipid particles, as well as on the solid lipid used.     

The future of enzymes in cosmetics

The skin employs a host of protective mechanisms to defend itself against the ravages of the environment. One of the most widely studied protective mechanisms is the system of free radical scavengers. Free radical scavengers help to protect the skin by neutralizing dangerous substances that can be generated by sun exposure and pollution. Two such protective substances - superoxide dismutase and peroxidase - were examined for their ability to reduce UV-induced erythema. The ability to reduce erythema is a measure of anti-irritant capabilities, which can also be thought of as free radical scavenging ability. There has been some research that shows that superoxide dismutase (SOD) and peroxidase work synergistically. The action of SOD, which neutralizes the superoxide anion, can sometimes produce hydrogen peroxide, which can have a detrimental effect on the lipid barriers of the skin. When peroxidase is present, it can work to neutralize the hydrogen peroxide, thus giving a full spectrum of free radical protection. The present study employs a superoxide dismutase extracted from yeast. The peroxidase is found in an aqueous extract of fennel (Foeniculum vulgare). Minimal erythemal dose (MED) was determined on the panellists. Test compounds were then applied and then they were exposed to solar simulators in doses equivalent to their respective MEDs. Development of erythema was then measured via chromameter, and reduction in the development of redness was determined.     

SCREENING ANTIOXIDATIVE AND PROOXIDATIVE ACTIVITY IN A SOLID MEDIUM MODEL SYSTEM

A variety of substances was evaluated for antioxidant or prooxidant activity in an aqueous model system of linoleic acid, Triton X-100, and 2-thiobarbituric acid solidified with agar in a Petri plate. Test samples were applied to wells cut from media. The oxidation reaction was initiated with ferric/ferrous chloride (50 mM/50 mM). Quantitative data were obtained by determining the diameter of the reaction ring surrounding test substance. Test substances and linoleic acid were oxidized, then subjected to the 2-thiobarbituric acid (TBA) test for comparison. Simulated food systems were also tested using both systems. Correlation coefficients between the test method (inverse ring diameter, cm) and nmoles malondialdehyde/ml measured by the TBA test were r = 0.98, 0.90, and 0.91 for BHA, vitamins E and C, respectively.     

Research on a natural sunscreen from Chinese herbs

To compare the difference in SPF values between a synthetic sunscreen and a sunscreen derived from Chinese herbs, by using optical and biological methods, we observed the effects of these sunscreens by photochemical reaction, sun protection factor (SPF) values, and UV absorption. The results showed that the synthetic sunscreen was more effective in UV absorption than the sunscreen derived from natural Chinese herbs. When they were tested biologically, it was found that the sunscreen derived from Chinese herbs was able to improve skin tonicity, as well as reduce the itching, photoerythema, squamation, burning, and reddening caused by the excessive UV radiation, while the synthetic sunscreen could not improve these conditions of the skin, and even induced some side-effects in the skin with photoerythema. By comparing the in vivo SPF values of the two types of sunscreen, they were found to be mainly similar. The results indicate that the SPF value was related to both a photo-reaction and a biological reaction. The sunscreen derived from natural Chinese herbs, although having low UV absorption, was able to exhibit the same SPF value as the synthetic sunscreen because of its biological effects.     

3种高粱品种淀粉特性和酿造黄酒的风味品质分析

以‘晋杂22号’、‘晋粱白2号’、‘晋粱白3号’3 种高粱为原料酿造黄酒,分析研究淀粉对黄酒风味品质的影响。对3 种高粱进行淀粉、直链淀粉、蛋白质和脂肪质量分数等理化指标的检测;并采用扫描电子显微镜分别对3 种高粱籽粒内部胚乳结构进行分析;对3 种高粱进行淀粉提取,检测其溶解度和膨胀度;并采用差示扫描量热仪检测3 种淀粉的糊化特性;采用3 种高粱进行发酵酿造黄酒,并对3 种高粱发酵过程中的挥发性风味物质的种类和质量浓度进行检测。结果表明,3 种黄酒分别检测到102、109、110 种风味物质,总质量浓度分别为392.210、344.342、635.695 mg/L,其中异丁醇、异戊醇、苯乙醇、十六酸乙酯、9,12-十八碳二烯酸乙酯和2-甲氧基-4-乙烯基苯酚是主要的风味物质。‘晋粱白3号’的支链淀粉质量分数最高,风味物质的种类及质量浓度也最高,证明淀粉质量分数对黄酒风味物质的种类及质量浓度起到了积极影响,为黄酒酿酒原料的选择提供了理论依据。     

食品中氯丙醇脂肪酸酯含量测定的方法研究

基于GB 5009.191—2016《食品安全国家标准食品中氯丙醇及其脂肪酸酯含量的测定》,对3-氯-1,2-丙二醇脂肪酸酯和2-氯-1,3-丙二醇脂肪酸酯及其内标绝对响应值较低、多个实验室间数据差异较大等问题进行了研究,重点对正己烷、不同酯键断裂试剂和反应时间进行了验证和优化。结果表明:正己烷对测试结果无影响,最佳的酯键断裂试剂为0.5 mol/L甲醇钠-甲醇溶液,最佳酯键断裂反应时间为2 min。通过国际比对和多品牌标准品比较,确定了多个实验室间数据差异较大原因主要来自于内标物质的纯度差异以及标准曲线内标物质与样品中加入的内标物质不同。建议样品测试时,应尽可能使标准曲线使用的标准物质及内标物质与样品中添加的内标物质相同,并同法处理,从而提高数据准确性。     

Evaulation of irritation potential of surfactant mixtures

Irritation potential of sodium laureth sulfate (SLES) alone, and in combination with lauryl glucoside (LG), polysorbate 20 (PS) and cocoamidopropyl betaine (CAPB) was tested in 13 human subjects. Four main and six sub-formulations were prepared and evaluated. Formulations were applied to the forearm as a 24 h close patch study. Irritation was scored by two different methods using an in vivo clinical protocol based on visual scoring and on the stratum corneum capacitance measurement. Irritation was found to be dose dependent. At 2 mg/patch level ten subjects did not show any skin reaction. At 20 mg/patch level eleven subjects showed a broad range of skin irritation. The highest irritation was observed with the formula that contained SLES, LG, and cocamide DEA together. Among the sub-formulations, cocamide DEA showed the highest irritation grade. A statistically significant correlation was observed between visual, clinical and corneometer scores. It was concluded that the irritation potential of surfactants was related to the total surfactant concentration, application mode, and the thermodynamic activity of molecules in the solution as well as the chemical structure of the surfactant molecules.     

5 个调色葡萄品种酚类物质轮廓分析

对调色葡萄品种‘烟73’、‘烟74’、‘Kolor’、‘Tintorera’和‘Dornfelder’成熟期果实和小规模发酵的葡萄酒进行基本理化指标和酚类物质分析。结果表明,‘Kolor’和‘烟73’果实花色苷含量较高,均超过4?000?mg/kg（以果实鲜质量计）;‘Tintorera’和‘烟73’果实黄酮醇含量较低,分别为43.99?mg/kg和59.6?mg/kg（以果实鲜质量计）;‘Dornfelder’果皮黄烷醇含量最低。在5?个调色葡萄酿造的葡萄酒中,‘烟73’的花色苷质量浓度最高（1?827.87?mg/L）;‘Tintorera’葡萄酒中黄酮醇（19.87?mg/L）、黄烷醇（35.34?mg/L）和酚酸（43.77?mg/L）质量浓度都低于其他品种。对果实花色苷含量进行主成分分析,能将大部分品种很好地区分。在此基础上构建正交偏最小二乘判别分析模型,能将各品种的果皮和果肉很好地区分,筛选出的差异物质大多为F3’5’H羟基取代花色苷。利用葡萄果实和葡萄酒中共同的酚类物质构建Pearson相关系数模型,结果显示,有70.37%的物质具有较强的相关性。本研究针对调色葡萄的酚类物质轮廓进行分析,能为干红葡萄酒以颜色和辅色为目的的调配提供基础。     

Incorporation of triterpenic derivatives within an o/w/o multiple emulsion: structure and release studies

Triterpenic derivatives stimulate the total collagen synthesis of skin fibroblasts. Their incorporation within an o/ w/o multiple emulsion should protect them against oxidation, particularly for unsaturated derivatives and should lead to a modulated release after topical application. The influence of the incorporation of madecassic acid, asiaticoside and asiatic acid on the viscosity and the stability of a multiple o/w/o emulsion was studied. Rheological analyses were carried out by flow experiments in order to obtain the apparent viscosity and by the oscillatory technique to calculate the basic visceolastic parameters. The comparative stability study was assessed by the tracer release method with phthalic acid diethyl ester previously incorporated in the internal phase of the emulsions. Six months storage at room temperature and at 40 degrees C did not affect the stability of emulsions with triterpenic substances. The in vitro percutaneous absorption of triterpenic derivatives was investigated by Franz diffusion cells in hairless rats. Triterpenic derivatives were analysed in stratum corneum, epidermis and dermis, by liquid chromatography. Correlations were established between the triterpenic derivatives structure (glycosylated or not) and their percutaneous absorption. O/w/o multiple emulsion seems to be an efficient vehicle to preserve these active substances and to control their distribution in the skin.     

Pectic substances in onion and garlic skins

Pectic substances from onion (white and red varieties) and garlic skins were isolated by extraction with ammonium oxalate. White onion and garlic skins were found to contain 11 to 12% pectin which can be recovered as a by-product in the dehydration industries. Characterisation of these pectic substances in terms of jelly grade, molecular weight, degree of esterification, methoxyl and uronide content was attempted. Pectins from white onions were superior to red onions in terms of jelly grade. Both types of onion pectins appeared to be of the rapid set type while the garlic skin pectin was of the medium set variety. Equivalent weight, methoxyl content and degree of esterification by themselves did not give any clear indication of pectin grade. Intrinsic viscosity values gave good correlation between jelly grade and molecular weight. The pectic substances from garlic skin differed from onion skin in certain respects and most remarkably in its viscosity behaviour.     

Disinfection of virus on hands for prevention of food-borne disease

Various ways in which virus could be transferred from contaminated hands to other persons through foods and fomites were examined. Methods of disinfecting contaminated hands were studied using in vitro (tube) tests, as well as both swine skin and human fingers as models. Almost all chemical hand disinfectants except a 500 ppm NaOCl solution were either ineffective aganst virus or were too harsh for normal hand use. Surprisingly, one of the most antiviral substances tested was ordinary tapwater collected from two locations on a University campus; water from surrounding municipalities, private wells, and lakes did not show the same antiviral activity. The use of plastic disposable gloves as a preventive measure is discussed.     

The protective effects of long-term oral administration of marine collagen hydrolysate from chum salmon on collagen matrix homeostasis in the chronological aged skin of Sprague-Dawley male rats

To investigate the long-term effects of marine collagen hydrolysate (MCH) from Chum Salmon skin on the aberrant collagen matrix homeostasis in chronological aged skin, Sprague-Dawley male rats of 4-wk-old were orally administrated with MCH at the diet concentrations of 2.25% and 4.5% for 24 mo. Histological and biochemical analysis revealed that MCH had the potential to inhibit the collagen loss and collagen fragmentation in chronological aged skin. Based on immunohistochemistry and western blot analysis, collagen type I and III protein expression levels in MCH-treated groups significantly increased as compared with the aged control group. Furthermore, quantitative real-time polymerase chain reaction and western blot analysis showed MCH was able to increase the expressions of procollagen type I and III mRNA (COL1A2 and COL3A1) through activating Smad signaling pathway with up-regulated TGF-βRII (TβRII) expression level. Meanwhile, MCH was shown to inhibit the age-related increased collagen degradation through attenuating MMP-1 expression and increasing tissue inhibitor of metalloproteinases-1 expression in a dose-dependent manner. Moreover, MCH could alleviate the oxidative stress in chronological aged skin, which was revealed from the data of superoxide dismutase activity and the thiobarbituric acid reactive substances level in skin homogenates. Therefore, MCH was demonstrated to have the protective effects on chronological skin aging due to the influence on collagen matrix homeostasis. And the antioxidative property of MCH might play an important role in the process.     

Antioxidant kinetics of plant-derived substances and extracts

The antioxidant activity (AA) of substances present in several plant species has been widely studied which reflects their fundamental role in the protection of skin tissue against the harmful action of reactive oxygen species. Given the importance of effective and long‐lasting protection against ultraviolet radiation, we studied the AA of several plant derivatives and extracts over time. Several chemical in vitro methods may be used to evaluate antioxidant capability, among which the 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH) method stands out, despite its unspecificity, as the most cited and described method in the literature. In this work the AA was evaluated by measuring their capacity to reduce DPPH in 30 min, which is suggested in the literature, and additionally at different times up to 8 h from the baseline reading. The methodology used to evaluate the AA over time was validated. It is important to emphasize that this study proposes to modify the conventional DPPH method, although considered to be non‐specific, to be used to test new antioxidant agents. This represents a considerable advantage because some substances show no significant activity during the first 30 min of reaction. Among other plant products, we tested a proantocyanidin‐rich grapeseed extract, a hesperidin derivative, a rutin‐containing ginkgo extract, a polyphenol‐containing yerba maté extract and tocopheryl acetate, all of which were properly standardized. As they have different antioxidant profiles, each ingredient showed a specific behaviour over time, which may promote the selection of anti‐radical compounds capable of offering protection against external agents. Combining extracts and plant derivatives that present fast, medium and slow antioxidant kinetic it is possible to create complexes capable of offering an effective protection from the moment of application up to several hours later. It is a perfectly feasible method, and such combinations prove to be more effective and have more durable effect.     

空气炸鱼皮工艺优化及其风味分析

为开发空气炸鱼皮产品,对鱼皮进行空气炸制工艺优化并对其风味进行分析。在单因素的基础上结合混水平均匀设计研究烫漂时间、盐水质量分数、盐水浸泡时间、腌制时间、预干燥温度及时间、空气炸温度及时间对空气炸鱼皮的影响。结果表明:空气炸鱼皮的最佳配方为烫漂时间8 s、盐水质量分数为1%、盐水浸泡时间为20 min、腌制时间36 min、预干燥温度为55 ℃、预干燥时间25 min、空气炸温度为190 ℃、空气炸时间为16 min。利用气相色谱-离子迁移谱（GC-IMS）技术,对最佳工艺条件下的空气炸鱼皮风味物质进行了分析,已定性的挥发性物质有40种,其中,己酸乙酯、己酸、反-2-辛烯醛、(E,E)-2,4-己二烯醛、2-庚酮、2,5-二甲基吡嗪、(E)-2-己烯醛、2-甲基吡嗪、异戊酸、2-甲基丁醛、1-辛醇、异戊醇、2-丙基-1-戊醇、2-乙基呋喃等含量较高,整体呈愉悦气味。本研究结果对空气炸系列产品的工艺和风味提供了一定的理论参考。