No full-text available
To read the full-text of this research,
you can request a copy directly from the authors.
Effects of Cosmetics and Their Preservatives on the Growth and Composition of Human Skin Microbiota
Abstract
We investigated the growth-inhibitory activities of cosmetics and their preservatives against pathogens and resident skin bacteria. Of the tested cosmetics, preservatives such as parabens, 1,2-hexanediol, phenoxyethanol-contained toner, emulsion, cream and baby cream exhibited potent antibacterial effects against Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa. Parabens, 1,2-hexanediol and phenoxyethanol inhibited the growth of pathogens, as well as skin-resident bacteria such as Staphilococcus epidermidis, Shigella flexneri, Enterobacter aerogenes and so on. The application of a basic cream containing phenoxyethanol to human skin was shown to disturb the skin microbiota: at the phylum level, Proteobacteria increased and at species level, 4P004125_s increased and Propionibacterium humerusii decreased. Based on these findings, parabens, 1,2-hexanediol and phenoxyethanol have antimicrobial activity and cosmetics containing phenoxyethanol may disturb skin microbiota.
... Scientific Committee on Consumer Safety, SCCS) potwierdził ostatnio bezpieczeństwo fenoksyetanolu -dostępne wyniki badań nie wskazują na toksyczność tego związku, zaś jego działanie drażniące wykazane było tylko w badaniach na zwierzętach w stężeniu 200-krotnie wyższym niż dozwolone u ludzi (1%) [15]. Z drugiej jednak strony, wyniki badań Jeong & Kim wykazały, że kosmetyki zawierające w swoim składzie fenoksyetanol mogą hamować wzrost mikrobioty skóry, co może być szczególnie niekorzystne u osób z problemami dermatologicznymi [16]. Kolejną grupą porównywanych składników były glikole, które w kosmetykach pełnią role humektantów, emulgatorów oraz substancji zwiększających lepkość. ...
Introduction: Cosmetic products for face care contain a number of chemicals which are applied to the skin every day. Despite the restrictive law regulations in Poland and the European Union, guaranteeing the safety of these products, there are still cases of adverse effects related to the use of cosmetics. Aim: Due to the growing interest of consumers in dermocosmetics and natural cosmetics, a comparative analysis of the ingredients in selected moisturizing face creams was performed. Materials and methods: The evaluation covered 30 moisturizing face creams available in drugstores, pharmacies and shops with natural products, classified as drugstore cosmetics, dermocosmetics and natural cosmetics, respectively. Results: Drugstore cosmetics had the widest range of ingredients and contained the most controversial substances, especially in the aspect of the used preservatives (imidazolidine urea, alcohol denaturated). Dermocosmetics were the group among with the highest number of products without potentially allergic fragrances and they also contained a lot of parafin-based emollients, which is beneficial for sensitive and atopic skin. However, the presence of potentially irritating substances (phenoxyethanol, polyethylene glycols) was also found. Natural cosmetics were mostly characterized by the presence of high-quality ingredients (herbal oils and extracts), but there were also products containing potentially irritating substances (limonene, linalool, citronellol, geraniol, phenoxyethanol and pentylene glycol). Conclusions: The chemical composition of cosmetics is of key importance in choosing the adequate product. Reliable information on individual ingredients coming from scientific sources is necessary to correctly assess their safety and identify the role played in the cosmetic product, which enables the verification of marketing declarations used by manufacturers. More efforts are needed to increase consumer awareness of exposure to substances derived from cosmetics.
... 16,17 Parabens, particularly propylparaben, exhibited the most potent antimicrobial e ects, followed by phenoxyethanol, against S. epidermis and S. aureus, which were isolated from the skin samples. 20,21 The low e cacy of methylparaben and phenoxyethanol were also seen in S. epidermis and S. aureus of Chinese population. 7 Conserving the homeostasis of the micro ora may prevent skin complications. ...
Objective:
The present study was designed to evaluate the effects of seven common preservatives used in Iranian cosmetic products on facial skin microflora.
Methods:
Fifteen healthy volunteers, aged 20 to 35 years, were recruited. Three symmetrical sites from the cheeks of each volunteer were selected and samples were collected. DNA was extracted from the culture using the boiling method. The fungi's internal transcribed spacer (ITS) region was amplified using ITS1/ITS4 primers, for 16s to identify bacteria and Staphylococcus specific primers. The effects of the preservatives were assessed based on growth on broth culture media.
Results:
Primary identification was based on yeast on CHROM agar, in which 15 different yeasts were isolated; then, PCR was used to identified the species as: C. albicans (n: 14; 93%), C. orthopsilosis (n: 1; 7%). One primary identified yeast on Dixon media was precisely differentiated as M. furfur using the PCR method. Fifteen primary identified cocci on tryptic soy agar media were identified as Staphylococcus epidermis. All the preservatives showed to inhibit the growth of isolated fungi, but not that of bacterial microflora.
Conclusion:
The present study showed preservatives in cosmetic products can alter skin microflora while also preventing the growth of pathogenic bacteria.
... The mechanism of action of preservatives, depending on the specific chemical compound, is based on the reduction of the membrane activity of microorganisms affecting the membrane potential, enzyme activity or membrane permeability, and other impacts. Parabens, 1,2-hexanediol and phenoxyethanol have been proven to inhibit not only the growth of pathogens but also the viability of skin-friendly microorganisms such as Staphilococcus epidermidis, Shigella flexneri, Enterobacter aerogenes, etc., thus upsetting the natural balance and exposing the skin to external irritation [22]. The study products were developed by using an alternative green preservative produced from non-edible elements of corn and sugarcane, as well as natural chelating agents as biodegradable replacements for EDTA, which significantly limit the irritation and causing possible allergic or otherwise adverse reactions on the skin. ...
Rosacea is a common chronic inflammatory skin disease, characterised by wavy course – exacerbation alternates with remission. Currently rosacea is not completely curable, but using appropriate pharmacological treatment, medical devices, appropriate daily skin care routine and educating patients, is possible to control a rosacea activity. This study aims on testing whether there is skin barrier improvement leads to associated rosacea symptoms decrease after the application of the products developed on natural emollient emulsion base with active ingredients of natural origin without the use of traditional preservatives and preservatives of natural origin with irritating potential. This was a prospective, single-centre, placebo-controlled, double-blind randomised pilot study. The enrolled participants were randomised to receive one of four interventions. The testing was performed by clinical grading, assessment of facial skin condition and determination of qualitative parameters with skin diagnostic device. The results show reduction in redness and red spots, which indicates the blood vessel-strengthening and anti-inflammatory properties of the product ingredients. The decrease of porphyrins was observed in all participant groups. The decrease of porphyrins was observed in all participant groups of the study, which is explained by the high quality of the product emollient base developed with plant oils.
... On the other hand, they often contain ingredients, e.g., preservatives, which have an inhibitory effect and disturb the microbiota. It has been shown, that cosmetic ingredients influence the skin microbiome and that microbial diversity can significantly change with the use of cosmetics [18][19][20][21][22]. However, to date no systematic studies have been performed. ...
Human skin is a complex ecosystem and is host to a large number of microorganisms. When the bacterial ecosystem is balanced and differentiated, skin remains healthy. However, the use of cosmetics can change this balance and promote the appearance of skin diseases. The skin’s microorganisms can utilize some cosmetic components, which either promote their growth, or produce metabolites that influence the skin environment. In this study, we tested the ability of the Malassezia species and some bacterial strains to assimilate substances frequently used in dermal formulations. The growth capability of microorganisms was determined and their lipase activity was analyzed. The growth of all Malassezia spp. in the presence of free acids, free acid esters, and fatty alcohols with a fatty chain length above 12 carbon atoms was observed. No growth was observed in the presence of fatty alcohol ethers, secondary fatty alcohols, paraffin- and silicon-based substances, polymers, polyethylene glycols, quaternary ammonium salts, hydroxy fatty acid esters, or fatty acids and fatty acid esters with a fatty chain length shorter than 12 carbon atoms. The hydrolysis of esters by Malassezia lipases was detected using High Performance Thin Layer Chromatography (HPTLC). The production of free fatty acids as well as fatty alcohols was observed. The growth promotion or inhibition of bacterial strains was only found in the presence of a few ingredients. Based on these results, formulations containing microbiome inert ingredients were developed.
Simvastatin reduces the blood concentration of cholesterol by inhibiting hydroxymethylglutaryl-coenzyme A reductase, the rate-limiting enzyme in cholesterol synthesis, and thereby reduces the risk of cardiovascular disease. In addition, simvastatin treatment leads to a reduction in fluxes in mitochondrial respiratory complexes I and II and might thereby reduce the formation of reactive oxygen species, which have been implicated in the pathogenesis of arteriosclerosis. Therefore, we hypothesized that simvastatin may reduce oxidative stress in humans in vivo.
We conducted a randomized, double-blinded, placebo-controlled study in which subjects were treated with either 40 mg of simvastatin or placebo for 14 days. The endpoints were six biomarkers for oxidative stress, which represent intracellular oxidative stress to nucleic acids, lipid peroxidation and plasma antioxidants, that were measured in urine and plasma samples.
A total of 40 participants were included, of which 39 completed the trial. The observed differences between simvastatin and placebo groups in the primary outcomes, DNA and RNA oxidation, were small and nonsignificant (p=0.68), specifically, 3% in the simvastatin group compared to 7.1% in the placebo group for DNA oxidation and 7.3% in the simvastatin group compared to 3.4% in the placebo group. The differences in biomarkers related to plasma were not statistically significant between the treatments groups, with the exception of total vitamin E levels, which, as expected, were reduced in parallel with the reduction in plasma cholesterol.
In healthy young male volunteers, short-term simvastatin treatment, which considerably reduces cholesterol, does not lead to a clinically relevant reduction in a panel of measures of oxidative stress. Whether simvastatin has effects on oxidative stress in diseased populations, such as diabetes or hemochromatosis, where oxidative stress is prominent, is unknown but seems unlikely.
The Malassezia yeasts which belong to the physiological microflora of human skin have also been implicated in several dermatological disorders, including pityriasis versicolor (PV), atopic dermatitis (AD), and psoriasis (PS). The Malassezia genus has repeatedly been revised and it now accommodates 14 species, all but one being lipid-dependent species. The traditional, phenotype-based identification schemes of Malassezia species are fraught with interpretative ambiguities and inconsistencies, and are thus increasingly being supplemented or replaced by DNA typing methods. The aim of this study was to explore the species composition of Malassezia microflora on the skin of healthy volunteers and patients with AD and PS.
Species characterization was performed by conventional, culture-based methods and subsequently molecular techniques: PCR-RFLP and sequencing of the internal transcribed spacer (ITS) 1/2 regions and the D1/D2 domains of the 26S rRNA gene. The Chi-square test and Fisher's exact test were used for statistical analysis.
Malassezia sympodialis was the predominant species, having been cultured from 29 (82.9%) skin samples collected from 17 out of 18 subjects under the study. Whereas AD patients yielded exclusively M. sympodialis isolates, M. furfur isolates were observed only in PS patients. The isolation of M. sympodialis was statistically more frequent among AD patients and healthy volunteers than among PS patients (P < 0.03). Whether this mirrors any predilection of particular Malassezia species for certain clinical conditions needs to be further evaluated. The overall concordance between phenotypic and molecular methods was quite high (65%), with the discordant results being rather due to the presence of multiple species in a single culture (co-colonization) than true misidentification. All Malassezia isolates were susceptible to cyclopiroxolamine and azole drugs, with M. furfur isolates being somewhat more drug tolerant than other Malassezia species.
This study provides an important insight into the species composition of Malassezia microbiota in human skin. The predominance of M. sympodialis in both normal and pathologic skin, contrasts with other European countries, reporting M. globosa and M. restricta as the most frequently isolated Malassezia species.
The skin, the human body's largest organ, is home to a diverse and complex variety of innate and adaptive immune functions. Despite this potent immune system present at the cutaneous barrier, the skin encourages colonization by microorganisms. Characterization these microbial communities has enhanced our knowledge of the ecology of organisms present in normal skin; furthermore, studies have begun to bring to light the intimate relationships shared between host and resident microbes. In particular, it is apparent that just as host immunological factors and behaviors shape the composition of these communities, microbes present on the skin greatly impact the functions of human immunity. Thus, today the skin immune system should be considered a collective mixture of elements from the host and microbes acting in a mutualistic relationship. In this article we will review recent findings of the interactions of skin microbial communities with host immunity, and discuss the role that dysbiosis of these communities plays in diseases of the skin.
An abundant and diverse collection of bacteria, fungi, and viruses inhabits the human skin. These microorganisms vary between individuals and between different sites on the skin. The factors responsible for the unique variability of the skin microbiome are only partly understood, but results suggest that host genetic and environmental influences play a major role. Today, the steady accumulation of data describing the skin microbiome, combined with experiments designed to test the biological functions of surface microbes, has provided new insights into links between human physiology and skin microbiota. This review describes some of the current information regarding the skin microbiome and its impact on human health. Specifically, we summarize the present understanding of the function of microbe-host interactions on the skin and highlight some unique features that distinguish skin commensal organisms from pathogenic microbes.
Panax ginseng (family Araliaceae) which contains ginsenoside Rb1 as a main constituent is traditionally used as a remedy for cancer, inflammation, stress, and ageing. The ginsenoside Rb1 in orally administered ginseng is metabolized to bioactive compounds by gut microbiota before their absorptions to the blood. However, its metabolizing activities in individuals are significantly different as we previously demonstrated. Here, we selected 5 samples with fecal activity potently metabolizing ginsenoside Rb1 to compound K (FPG; metabolic activity, 0.058±0.029 pmol/min/mg) and 5 samples with fecal activity non-metabolizing ginsenoside Rb1 to compound K (FNG) from a pool of 100 subjects investigated in a previous study and analyzed fecal microbiota by 16S rRNA gene pyrosequencing. Taxonomy-based analysis showed that the population levels of Firmicutes and Proteobacteria in FPG were lower than in FNG, but those of Bacteroidetes and Tenericutes in FPG were higher than in FNG. At the genus level, the population levels of Clostridiales_uc_g, Oscillibacter, Ruminococcus, Holdemania, and Sutterella in FPG were significantly higher than in FNG, but that of Leuconostoc in FPG was lower than in FNG. The population levels of Bacteroides and Bifidobacterium, which potently metabolizes ginsenoside Rb1 to compound K were dramatically increased in FPG. The gut microbiota compositions of FPG and FNG were segregated on PCO2 by Principal Coordinate Analysis. Intestinal bacterial metabolism of ginseng, particularly ginsenoside Rb1, may be dependent on the composition of gut microbiota, such as Ruminococcus spp., Bacteroides spp. and Bifidobacterium spp.
The cosmetic industry adapts to the needs of consumers seeking to limit the use of preservatives and develop of preservative-free or self-preserving cosmetics, where preservatives are replaced by raw materials of plant origin. The aim of study was a comparison of the antimicrobial activity of extracts (Matricaria chamomilla, Aloe vera, Calendula officinalis) and essential oils (Lavandulla officinallis, Melaleuca alternifolia, Cinnamomum zeylanicum) with methylparaben. Extracts (2.5 %), essential oils (2.5 %) and methylparaben (0.4 %) were tested against Pseudomonas aeruginosa ATCC 27853, Escherichia coli ATCC 25922, Staphylococcus aureus ATCC 29213, Candida albicans ATCC 14053. Essentials oils showed higher inhibitory activity against tested microorganism strain than extracts and methylparaben. Depending on tested microorganism strain, all tested extracts and essential oils show antimicrobial activity 0.8–1.7 and 1–3.5 times stronger than methylparaben, respectively. This shows that tested extracts and essential oils could replace use of methylparaben, at the same time giving a guarantee of microbiological purity of the cosmetic under its use and storage.
Antimicrobial peptides serve as a first line of innate immune defense against invading organisms such as bacteria and viruses. In this study, we hypothesized that peptides produced by a normal microbial resident of human skin, Staphylococcus epidermidis, might also act as an antimicrobial shield and contribute to normal defense at the epidermal interface. We show by circular dichroism and tryptophan spectroscopy that phenol-soluble modulins (PSMs) gamma and delta produced by S. epidermidis have an alpha-helical character and a strong lipid membrane interaction similar to mammalian AMPs such as LL-37. Both PSMs directly induced lipid vesicle leakage and exerted selective antimicrobial action against skin pathogens such as Staphylococcus aureus. PSMs functionally cooperated with each other and LL-37 to enhance antimicrobial action. Moreover, PSMs reduced Group A Streptococcus (GAS) but not the survival of S. epidermidis on mouse skin. Thus, these data suggest that the production of PSMgamma and PSMdelta by S. epidermidis can benefit cutaneous immune defense by selectively inhibiting the survival of skin pathogens while maintaining the normal skin microbiome.
Rapid, accurate, and sensitive determination of antibiotic resistance profiles of various human and animal pathogens becomes a vital prerequisite for successful therapeutic intervention in the face of the increased occurrences of drug-resistant bacterial infections. The current methods, which are dependent on cultivation of pathogens and phenotypic expression of antibiotic resistance, usually require excessive time, special microbiological equipment, and qualified personnel. However, even with all these requisites, for example, no bacteria can be grown from more than 80% of all clinical samples sent to clinical microbiology laboratories (1). Besides the cultivation limitations, the cultivation-based determination of an antibiotic resistance profile lacks the genotypic information, which is essential for understanding the epidemiology and routes of transmission of antibiotic resistance genes. These genes often reside on mobile genetic elements and can move freely between commensal and pathogenic microbiota, occurring even between taxonomically distant clinical and environmental microbiota. Therefore, development of genotyping methods for detection of antibiotic resistance genes is highly desirable for fast, accurate, and sensitive detection of antibiotic resistance genes in a broad range of pathogenic and commensal bacteria in both clinical and environmental samples.
The US National Institute of Health-funded Human Microbiome Project Consortium started 6 years ago to characterize the human microbial communities (microbiota) present at specific body sites, and to analyze the role of these microbes in human health and disease. It was expected that more knowledge of our microbiome leads to more effective ways to diagnose, treat and eventually prevent diseases. This paper reviews the skin microbiome research and the relation of microorganisms to skin diseases. © 2014 De Nederlandse Vereniging voor Dermatologie en Venereologie.
The microbiota plays a fundamental role on the induction, training, and function of the host immune system. In return, the immune system has largely evolved as a means to maintain the symbiotic relationship of the host with these highly diverse and evolving microbes. When operating optimally, this immune system-microbiota alliance allows the induction of protective responses to pathogens and the maintenance of regulatory pathways involved in the maintenance of tolerance to innocuous antigens. However, in high-income countries, overuse of antibiotics, changes in diet, and elimination of constitutive partners, such as nematodes, may have selected for a microbiota that lack the resilience and diversity required to establish balanced immune responses. This phenomenon is proposed to account for some of the dramatic rise in autoimmune and inflammatory disorders in parts of the world where our symbiotic relationship with the microbiota has been the most affected.
This article reviews recent findings on the skin microbiome. It provides an update on the current understanding of the role of microbiota in healthy skin and in inflammatory and allergic skin diseases.
Advances in computing and high-throughput sequencing technology have enabled in-depth analysis of microbiota composition and functionality of human skin. Most data generated to date are related to the skin microbiome of healthy volunteers, but recent studies have also addressed the dynamics of the microbiome in diseased and injured skin. Currently, reports are emerging that evaluate the strategies to manipulate the skin microbiome, intending to modulate diseases and/or their symptoms.
The microbiome of normal human skin was found to have a high diversity and high interpersonal variation. Microbiota compositions of diseased lesional skin (in atopic dermatitis and psoriasis) showed distinct differences compared with healthy skin. The function of microbial colonization in establishing immune system homeostasis has been reported, whereas host-microbe interactions and genetically determined variation of stratum corneum properties might be linked to skin dysbiosis. Both are relevant for cutaneous disorders with aberrant immune responses and/or disturbed skin barrier function. Modulation of skin microbiota composition to restore host-microbiota homeostasis could be future strategies to treat or prevent disease.
The human body harbors 10 to 100 trillion microbes, mainly bacteria in our gut, which greatly outnumber our own human cells. This bacterial assemblage, referred to as the human microbiota, plays a fundamental role in our well-being. Deviations from healthy microbial compositions (dysbiosis) have been linked with important human diseases, including inflammation-linked disorders, such as allergies, obesity, and inflammatory bowel disease. Characterizing the temporal variations and community membership of the healthy human microbiome is critical to accurately identify the significant deviations from normality that could be associated with disease states. However, the diversity of the human microbiome varies between body sites, between patients, and over time. Environmental differences have also been shown to play a role in shaping the human microbiome in different cultures, requiring that the healthy human microbiome be characterized across life spans, ethnicities, nationalities, cultures, and geographic locales. In this article we summarize our knowledge on the microbial composition of the 5 best-characterized body sites (gut, skin, oral, airways, and vagina), focusing on interpersonal and intrapersonal variations and our current understanding of the sources of this variation.
Concern is continuously raised regarding the safety of preservatives, which are crucial in most cosmetic preparations. The antimicrobial effects of silver (Ag) are well recognized; however, Ag has some limitations as a preservative, such as its interference with salts. In this study, we investigated the effects of recently synthesized Ag nanoparticles on microorganisms, the permeability of Ag nanoparticles in human skin, and the cytotoxicity of Ag nanoparticles in human keratinocytes under ultraviolet B irradiation. Ag nanoparticles were found to be very stable, and they did not exhibit sedimentation for over 1 year. Ag nanoparticles showed sufficient preservation efficacy against mixed bacteria and mixed fungi, and did not penetrate normal human skin. At concentrations of 0.002-0.02 parts per million, Ag nanoparticles had no effect on HaCaT keratinocytes and did not enhance ultraviolet B-induced cell death. These results suggest that Ag nanoparticles may have potential for use as a preservative in cosmetics. From the clinical editor: In this study, the effects of recently synthesized Ag nanoparticles were investigated on microorganisms, along with the skin permeability and the cytotoxicity in human keratinocytes under UVB-irradiation. Ag nanoparticles were found to be very stable, showed sufficient preservation efficacy against mixed bacteria and mixed fungi, and did not penetrate normal human skin. Ag nanoparticles appear to be suitable for use as a preservative in cosmetics.
The use of alcohol-based hand rubs serves to reduce hospital-acquired infections. Many products of this type are now on offer and it is essential to know how to rank their efficacy. A sequence of tests is proposed here to compare any given new alcohol-based solution against the reference solution (60% 2-isopropyl-alcohol) with 30 s of contact time: (i) in vitro (with pig skin as carrier) testing of >30 species of microorganism; (ii) in vitro assessment of residual efficacy (after 30 min of drying); (iii) in vivo study of transient microbiota (modification of the EN 1500 standard procedure) using four ATCC strains; (iv) in vivo study of resident hand microbiota. After performing the in vitro evaluation of seven alcohol-based hand rubs, the two most efficacious (chlorhexidine-quac-alcohol and mecetronium- alcohol) were chosen and studied, comparatively with the reference solution (60% isopropyl alcohol), in vitro (for chemical sustainability on the skin) and in vivo (against transient and resident microbiota). Chlorhexidine-quac-alcohol proved to be significantly superior to mecetronium-alcohol or the reference solution in all tests, except against resident microbiota for which the improvement was not statistically significant.
Microbiota in healthy skin and in atopic eczema
- G Baviera
- M C Leoni
- L Capra
- F Cipriani
- G Longo
- N Maiello
- G Ricci
- E Galli
G. Baviera, M. C. Leoni, L. Capra, F. Cipriani, G.
Longo, N. Maiello, G. Ricci, and E. Galli, Microbiota
in healthy skin and in atopic eczema Biomed. Res.
Int., 2014, 436921 (2014).
Essential oils and herbal extracts as antimicrobial agents in cosmetic emulsion
- A Herman
- A P Herman
- B W Domagalska
- A Mynarczyk
A. Herman, A. P. Herman, B. W. Domagalska, and
A. Mynarczyk, Essential oils and herbal extracts as
antimicrobial agents in cosmetic emulsion, Indian J.
Microbiol., 53(2), 232 (2013).
for disinfection of the skin
for disinfection of the skin, Surg. Gynecol. Obstet.,
152(5), 677 (1981).