Recent advances in understanding Propionibacterium acnes ( Cutibacterium acnes) in acne

Effects of Light and Laser Therapies on the Microecosystem of Sebaceous Glands in Acne Treatment

BACKGROUND

Acne vulgaris (acne) is one of the most common skin diseases with complex pathogenesis. Numerous studies have shown that the microecosystem of sebaceous glands and Cutibacterium acnes play key roles in its pathogenesis. Antibiotics targeting C. acnes have been widely used in acne treatment, but the growing prevalence of antibiotic resistance has become alarming. Further research into the microecosystem of sebaceous glands and the role of specific C. acnes phylotypes in acne pathogenesis has led to a paradigm shift in acne treatment. Currently, non-antibiotic therapies such as light therapy and laser therapy are becoming increasingly popular, opening up new opportunities in acne management.

METHODS

Studies on the microecosystem of sebaceous glands associated with acne and the effects of light and laser therapies on the microecosystem in acne treatment were retrieved from the PubMed database.

RESULTS

Dysbiosis of the microecosystem of the pilosebaceous unit is closely related to the pathogenesis of acne. Light and laser therapies have an impact on the microecosystem of the pilosebaceous unit in acne treatment.

CONCLUSIONS

Light and laser therapies are the popular alternative options in acne treatment. The mechanisms of their effect on the microecosystem of sebaceous glands are not completely clear and require further research, especially for laser therapy.

Cutibacterium acnes bacteriophage therapy: exploring a new frontier in acne vulgaris treatment

The skin microbiome, encompassing a variety of microorganisms, plays a critical role in skin health and function. Acne vulgaris, affecting approximately 9.4% of the global population, is a prevalent skin condition primarily targeting pilosebaceous units rich in sebaceous glands. The condition is influenced by factors such as hormonal changes, sebaceous gland dysfunction, and the activity of Cutibacterium acnes, a gram-positive bacterium linked to acne development. The skin's immune system, particularly keratinocytes with pattern recognition receptors like Toll-like receptors (TLRs), plays a crucial role in recognizing and responding to bacterial presence. The onset of acne is often linked to adolescence, marked by significant hormonal fluctuations. Genetics also plays a role, with family history being a notable risk factor. Acne is characterized by distinct alterations in the C. acnes composition, with specific phylotypes associated with either commensal or pathogenic behavior. Traditional treatments include antibiotics, but the rise of antibiotic resistance has led to exploring alternative therapies, such as bacteriophage therapy. Bacteriophages offer a targeted approach to treating acne by targeting C. acnes strains, potentially reducing antibiotic resistance and enhancing treatment efficacy. Phage therapy shows promise, but further research is needed to fully understand its effectiveness and potential in clinical applications. Additionally, combining phages with antibiotics may offer a synergistic approach to overcoming antibiotic resistance and managing acne.

The primary role of sebum in the pathophysiology of acne vulgaris and its therapeutic relevance in acne management

BACKGROUND

Sebum physiology and its contributions to acne vulgaris (AV) pathophysiology have been long debated. Within the pilosebaceous unit, androgens drive sebocyte production of sebum, comprising mono-, di-, and triglycerides (the latter converted to fatty acids); squalene; cholesterol; cholesterol esters; and wax esters. Upon release to the skin surface, human sebum has important roles in epidermal water retention, antimicrobial defenses, and innate immune responses.

AIMS

Alterations in sebum alone and with other pathogenic factors (inflammation, follicular hyperkeratinization, and Cutibacterium acnes [C. acnes] proliferation) contribute to AV pathophysiology. Androgen-driven sebum production, mandatory for AV development, propagates C. acnes proliferation and upregulates inflammatory and comedogenic cascades.

RESULTS

Some sebum lipids have comedogenic effects in isolation, and sebum content alterations (including elevations in specific fatty acids) contribute to AV pathogenesis. Regional differences in facial sebum production, coupled with patient characteristics (including sex and age), help exemplify this link between sebum alterations and AV lesion formation.

CONCLUSIONS

To date, only combined oral contraceptives and oral spironolactone (both limited to female patients), oral isotretinoin and topical clascoterone (cortexolone 17α-propionate) modulate sebum production in patients with AV. A better understanding of mechanisms underlying sebaceous gland changes driving AV development is needed to expand the AV treatment armamentarium.

Photodynamic Therapy in Acne Vulgaris: A Systematic Review

Acne is a multifactorial disorder of the pilosebaceous unit. Photodynamic therapy (PDT) is an energy-based treatment shown to be safe in acne vulgaris, although the mechanism of action of PDT in acne is incompletely understood. This review summarizes the clinical features of and treatment efficacy in acne patients treated with PDT. A systematic review of Medline, Embase, and the Cochrane Database of Systematic Reviews was conducted. Title, abstract, full-text screening, and data extraction were completed using Covidence. Studies reporting the use of PDT in patients with acne were included while clinical features and treatment responses were extracted. Treatment outcomes were scored as complete response, partial response, and no response. After screening a total of 1122 studies, 82 studies met the inclusion criteria, representing 56 prospective studies, 25 randomized controlled trials, and 1 retrospective study. Results representing 4340 patients with acne (mean age 24.4 years; 52% females) treated with PDT are summarized. Overall, 2154 (50%) participants underwent aminolevulinic acid PDT, 452 (10%) participants underwent methyl aminolevulinate PDT, 28 (<1%) participants underwent daylight PDT, and 1706 (39%) underwent other modalities of PDT. The average follow-up period after study completion was 3 months, ranging from 2 weeks to 13 months. A partial response was observed in treated patients with outcome measures including clinical response, lesion count, pain, recurrence, and patient satisfaction. This systematic review provides preliminary data summarizing the clinical features and treatment efficacy in patients with acne treated with PDT. Our results suggest a partial clinical response when using PDT to manage acne. Future studies should focus on standardizing study protocols and drawing direct comparisons between PDT and other modalities for acne treatment.

Biofilm of Cutibacterium acnes: a target of different active substances

BACKGROUND

Acne vulgaris is a chronic inflammatory dermatosis. Cutibacterium acnes plays a crucial role in the acne pathophysiology. Recent works present evidence of C. acnes growing as a biofilm in cutaneous follicles. This development is currently considered one of the leading causes of C. acnes in vivo persistence and resistance to antimicrobials used to treat acne.

OBJECTIVE

Our objective was to evaluate the effects of various active compounds (clindamycin, erythromycin, doxycycline, and myrtle extract) on eight distinct, well-characterized strains of C. acnes following their growth in biofilm mode.

METHODS/RESULTS

Cutibacterium acnes isolates from phylotypes IA1 and IA2 produce more biofilm than other phylotypes. No antibiotic effect was observed either during the curative test or preventive test. Myrtle extract at 0.01% (w/v) showed significant efficacy on the biofilm for C. acnes strains (curative assays). Furthermore, it appear that myrtle extract and doxycycline together reduce the overall biomass of the biofilm. A significant dose-dependent effect was observed during the preventive test, greater than the one observed under curative conditions, with an important loss of activity of the myrtle extract observed from 0.001% (w/v) concentration onwards. Transmission electron microscopy showed that bacteria treated with myrtle extract grew biofilms much less frequently than untreated bacteria. Additionally, when the quantity of myrtle extract grew, the overall number of bacteria dropped, indicating an additional antibacterial action.

CONCLUSION

These findings support the hypothesis that the different C. acnes phylotypes have various aptitudes in forming biofilms. They also suggest that myrtle extract is a promising alternative as an anti-biofilm and antibacterial agent in fighting diseases caused by planktonic and biofilm C. acnes.

The Potential Role of Cannabidiol in Cosmetic Dermatology: A Literature Review

Cannabidiol (CBD) is a non-psychotropic cannabinoid with multiple pharmacological properties. Cannabidiol has attracted growing attention in the cosmetic industry, with an increasing number of CBD-containing skincare products on the market in recent years. The aim of this review is to evaluate the current evidence on the use of CBD for cosmetic purposes. Following an overview of CBD and the endocannabinoid system in the skin, we summarize pre-clinical and clinical studies that address the potential of CBD in cosmetic dermatology. Available in vitro and in vivo evidence suggests that CBD has anti-oxidant, anti-inflammatory, moisturizing, anti-acne, wound-healing, and anti-aging properties. However, only a few clinical studies have been conducted on the use of CBD in the skin. In addition, there is a critical need to develop an efficient drug-delivery system for topical/transdermal application of CBD. Further research, including clinical and pharmacokinetic studies, are needed to fully evaluate the role of CBD in cosmetic dermatology.

Elevating Skincare Science: Grape Seed Extract Encapsulation for Dermatological Care

The skin is the largest organ in the human body and serves multiple functions such as barrier protection and thermoregulation. The maintenance of its integrity and healthy structure is of paramount importance. Accordingly, technological advances in cosmetic sciences have been directed towards optimizing these factors. Plant-derived ingredients have been explored for their bioactivity profiles and sustainable sources. Grape by-products contain a group of bioactive molecules that display important biological activities. Nonetheless, many of these molecules (e.g., phenolic compounds) are unstable and susceptible to degradation. So, their encapsulation using nano/microsystems (i.e., microdispersions) has been explored as a promising solution. In this work, two grape seed extracts were obtained, one from a single grape variety (GSE-Ov) and another from a mix of five grape varieties (GSE-Sv). These extracts were analysed for their antioxidant and antimicrobial activities, as well as their chemical composition and molecular structure. The extract that showed the most promising properties was GSE-Ov with a DPPH IC50 of 0.079 mg mL-1. This extract was encapsulated in soy lecithin microdispersions coated with pectin, with an encapsulation efficiency of 88.8%. They showed an in vitro release of polyphenols of 59.4% during 24 h. The particles displayed a zeta potential of -20.3 mV and an average diameter of 13.6 µm. Microdispersions proved to be safe under 5 and 2.5 mg mL-1 in HaCaT and HDF cell models, respectively. Additionally, they demonstrated anti-inflammatory activity against IL-1α when tested at 2 mg mL-1. This work enabled the valorisation of a by-product from the wine industry by using natural extracts in skincare products.

Clindamycin: A Comprehensive Status Report with Emphasis on Use in Dermatology

Clindamycin is a lincosamide antibiotic that has been used as a topical, oral, or injectable formulation for over five decades. It exhibits a narrow spectrum of microbiologic activity, primarily against gram-positive and anaerobic bacteria. In dermatology, clindamycin has been used primarily as a topical agent, usually for the treatment of acne vulgaris. Despite questions surrounding antibiotic resistance and/or its relative contribution to antibiotic treatment efficacy, a large body of data support the therapeutic value of topical clindamycin for acne vulgaris. As a systemic agent, clindamycin is used orally to treat a variety of cutaneous bacterial infections, and sometimes for acne vulgaris, with oral treatment for the latter less common in more recent years. The modes of action of clindamycin are supported by data showing both its anti-inflammatory and antibiotic mechanisms, which are discussed here along with pharmacokinetic profiles and structure-activity relationships. The diverse applications of clindamycin for multiple disease states, its efficacy, and safety considerations are also reviewed here, including for both topical and systemic formulations. Emphasis is placed on uses in dermatology, but other information on clindamycin relevant to clinicians is also discussed.

Carbon source competition within the wound microenvironment can significantly influence infection progression

It is becoming increasingly apparent that commensal skin bacteria have an important role in wound healing and infection progression. However, the precise mechanisms underpinning many of these probiotic interactions remain to be fully uncovered. In this work, we demonstrate that the common skin commensal Cutibacterium acnes can limit the pathogenicity of the prevalent wound pathogen Pseudomonas aeruginosa in vivo. We show that this impact on pathogenicity is independent of any effect on growth, but occurs through a significant downregulation of the Type Three Secretion System (T3SS), the primary toxin secretion system utilised by P. aeruginosa in eukaryotic infection. We also show a downregulation in glucose acquisition systems, a known regulator of the T3SS, suggesting that glucose availability in a wound can influence infection progression. C. acnes is well known as a glucose fermenting organism, and we demonstrate that topically supplementing a wound with glucose reverses the probiotic effects of C. acnes. This suggests that introducing carbon source competition within the wound microenvironment may be an effective way to prevent or limit wound infection.

Repurposing lipid-lowering drugs as potential treatment for acne vulgaris: a Mendelian randomization study

Background

Acne vulgaris, a chronic inflammatory skin condition predominantly seen in teenagers, impacts more than 640 million people worldwide. The potential use of lipid-lowering medications as a treatment for acne vulgaris remains underexplored. This study seeks to investigate the impact of lipid-lowering therapies on the risk of developing acne vulgaris using two-sample Mendelian randomization (MR) analysis.

Method

The two-sample MR method was employed for analysis, and information on lipid-lowering drugs was obtained from the DrugBank and ChEMBL databases. The summary data for blood low-density lipoprotein (LDL) and triglycerides were sourced from the Global Lipids Genetics Consortium, while genome-wide association studies (GWAS) summary data for acne vulgaris were obtained from the FinnGen database. Heterogeneity was examined using the Q-test, horizontal pleiotropy was assessed using MR-Presso, and the robustness of analysis results was evaluated using leave-one-out analysis.

Results

The MR analysis provided robust evidence for an association between lowering LDL cholesterol through two drug targets and acne vulgaris, with PCSK9 showing an odds ratio (OR) of 1.782 (95%CI: 1.129-2.812, p = 0.013) and LDL receptor (LDLR) with an OR of 1.581 (95%CI: 1.071-2.334, p = 0.021). Similarly, targeting the lowering of triglycerides through lipoprotein lipase (LPL) was significantly associated with an increased risk of acne vulgaris, indicated by an OR of 1.607 (95%CI: 1.124-2.299, p = 0.009).

Conclusion

The current MR study presented suggestive evidence of a positive association between drugs targeting three genes (PCSK9, LDLR, and LPL) to lower lipids and a reduced risk of acne vulgaris.

Efficacy of Glycyrrhetinic Acid in the Treatment of Acne Vulgaris Based on Network Pharmacology and Experimental Validation

Glycyrrhetinic acid (GA) is a saponin compound, isolated from licorice (Glycyrrhiza glabra), which has been wildly explored for its intriguing pharmacological and medicinal effects. GA is a triterpenoid glycoside displaying an array of pharmacological and biological activities, including anti-inflammatory, anti-bacterial, antiviral and antioxidative properties. In this study, we investigated the underlying mechanisms of GA on acne vulgaris through network pharmacology and proteomics. After the intersection of the 154 drug targets and 581 disease targets, 37 therapeutic targets for GA against acne were obtained. A protein-protein interaction (PPI) network analysis highlighted TNF, IL1B, IL6, ESR1, PPARG, NFKB1, STAT3 and TLR4 as key targets of GA against acne, which is further verified by molecular docking. The experimental results showed that GA inhibited lipid synthesis in vitro and in vivo, improved the histopathological damage of skin, prevented mast cell infiltration and decreased the level of pro-inflammatory cytokines, including TNF-α, IL-1β and IL-6. This study indicates that GA may regulate multiple pathways to improve acne symptoms, and the beneficial effects of GA against acne vulgaris might be through the regulation of sebogenesis and inflammatory responses.

Interleukin-1 family cytokines at the crossroads of microbiome regulation in barrier health and disease

Recent advances in understanding how the microbiome can influence both the physiology and the pathogenesis of disease in humans have highlighted the importance of gaining a deeper insight into the complexities of the host-microbial dialogue. In tandem with this progress, has been a greater understanding of the biological pathways which regulate both homeostasis and inflammation at barrier tissue sites, such as the skin and the gut. In this regard, the Interleukin-1 family of cytokines, which can be segregated into IL-1, IL-18 and IL-36 subfamilies, have emerged as important custodians of barrier health and immunity. With established roles as orchestrators of various inflammatory diseases in both the skin and intestine, it is now becoming clear that IL-1 family cytokine activity is not only directly influenced by external microbes, but can also play important roles in shaping the composition of the microbiome at barrier sites. This review explores the current knowledge surrounding the evidence that places these cytokines as key mediators at the interface between the microbiome and human health and disease at the skin and intestinal barrier tissues.

In silico studies on the anti-acne potential of Garcinia mangostana xanthones and benzophenones

Garcinia mangostana fruits are used traditionally for inflammatory skin conditions, including acne. In this study, an in silico approach was employed to predict the interactions of G. mangostana xanthones and benzophenones with three proteins involved in the pathogenicity of acne, namely the human JNK1, Cutibacterium acnes KAS III and exo-β-1,4-mannosidase. Molecular docking analysis was performed using Autodock Vina. The highest docking scores and size-independent ligand efficiency values towards JNK1, C. acnes KAS III and exo-β-1,4-mannosidase were obtained for garcinoxanthone T, gentisein/2,4,6,3',5'-pentahydroxybenzophenone and mangostanaxanthone VI, respectively. To the best of our knowledge, this is the first report of the potential of xanthones and benzophenones to interact with C. acnes KAS III. Molecular dynamics simulations using GROMACS indicated that the JNK1-garcinoxanthone T complex had the highest stability of all ligand-protein complexes, with a high number of hydrogen bonds predicted to form between this ligand and its target. Petra/Osiris/Molinspiration (POM) analysis was also conducted to determine pharmacophore sites and predict the molecular properties of ligands influencing ADMET. All ligands, except for mangostanaxanthone VI, showed good membrane permeability. Garcinoxanthone T, gentisein and 2,4,6,3',5'-pentahydroxybenzophenone were identified as the most promising compounds to explore further, including in experimental studies, for their anti-acne potential.

Effects of Mannosylerythritol-Lipids-B on Cutibacterium acnes ATCC 6919

Mannosylerythritol-lipids-B (MEL-B) are microbial-produced glycolipids with skincare properties, notably moisturizing, antimelanogenic, antimicrobial, and antiaging. Thus, there is a potential use of MEL-B in a formulation for treating acne-prone skin. This study investigated the antimicrobial effect of MEL-B against the Gram-positive bacteria Cutibacterium acnes. The broth macro dilution method was used to evaluate the growth of C. acnes (3-4 CFU/mL), in the absence (positive control) or presence of MEL-B (128, 192, 256, and 512 μg/mL). Additionally, the leakage of genetic materials was used to determine the potential drug-induced membrane disruption of glycolipids. The amount of DNA and RNA release was quantified spectrophotometrically at 260 nm. Macro dilution technique and membrane integrity experiments showed that MEL-B does not have antimicrobial activity against C. acnes. Indeed, MEL-B assisted C. acnes growth. Ultimately, MEL-B has been reported as a remarkably active compound for skincare formulations; however, preliminarily, it should be avoided for acneic skin.

Anti-Bacterial Activity of Green Synthesised Silver and Zinc Oxide Nanoparticles against Propionibacterium acnes

Propionibacterium acnes plays a critical role in the development of acne vulgaris. There has been a rise in the number of patients carrying P. acnes strains that are resistant to antibiotics. Thus, alternative anti-microbial agents are required. Zinc oxide (ZnO-NPs) and silver (Ag-NPs) nanoparticles can be used against several antibiotic-resistant bacteria. The impact of Ag-NPs and ZnO-NPs against two clinical strains of P. acnes, P1 and P2, and a reference strain, NCTC747, were investigated in this research. A chemical approach for the green synthesis of Ag-NPs and ZnO-NPs from Peganum harmala was employed. The microtiter plate method was used to examine the effects of NPs on bacterial growth, biofilm development, and biofilm eradication. A broth microdilution process was performed in order to determine minimal inhibitory (MIC) concentrations. Ag-NPs and ZnO-NPs had a spherical shape and average dimensions of 10 and 50 nm, respectively. MIC values for all P. acnes strains for Ag-NPs and ZnO-NPs were 125 µg/mL and 250 µg/mL, respectively. Ag-NP and ZnO-NP concentrations of 3.9- 62.5 µg/mL and 15-62.5 µg/mL significantly inhibited the growth and biofilm formation of all P. acnes strains, respectively. ZnO-NP concentrations of 15-62.5 μg/mL significantly inhibited the growth of NCTC747 and P2 strains. The growth of P1 was impacted by concentrations of 31.25 μg/mL and 62.5 μg/mL. Biofilm formation in the NCTC747 strain was diminished by a ZnO-NP concentration of 15 μg/mL. The clinical strains of P. acnes were only affected by ZnO-NP titres of more than 31.25 μg/mL. Established P. acne biofilm biomass was significantly reduced in all strains at a Ag-NP and ZnO-NP concentration of 62.5 µg/mL. The findings demonstrated that Ag-NPs and ZnO-NPs exert an anti-bacterial effect against P. acnes. Further research is required to determine their potential utility as a treatment option for acne.

Colloidal hydrogel systems of thymol-loaded PLGA nanoparticles designed for acne treatment

Thymol-loaded PLGA nanoparticles (TH-NPs) were incorporated into different semi-solid formulations using variable gelling agents (carbomer, polysaccharide and poloxamer). The formulations were physicochemically characterized in terms of size, polydispersity index and zeta potential. Moreover, stability studies were performed by analyzing the backscattering profile showing that the gels were able to increase the nanoparticles stability at 4 °C. Moreover, rheological properties showed that all gels were able to increase the viscosity of TH-NPs with the carbomer gels showing the highest values. Moreover, the observation of carbomer dispersed TH-NPs under electron microscopical techniques showed 3D nanometric cross-linked filaments with the NPs found embedded in the threads. In addition, cytotoxicity studies showed that keratinocyte cells in contact with the formulations obtained cell viability values higher than 70 %. Furthermore, antimicrobial efficacy was assessed against C. acnes and S. epidermidis showing that the formulations eliminated the pathogenic C. acnes but preserved the resident S. epidermidis which contributes towards a healthy skin microbiota. Finally, biomechanical properties of TH-NPs dispersed in carbomer gels in contact with healthy human skin were studied showing that they did not alter skin properties and were able to reduce sebum which is increased in acne vulgaris. As a conclusion, TH-NPs dispersed in semi-solid formulations and, especially in carbomer gels, may constitute a suitable solution for the treatment of acne vulgaris.

The Microbiome and Acne: Perspectives for Treatment

The skin microbiome consists of the microorganisms populating the human skin. Cutibacterium acnes (C. acnes, formerly named Propionibacterium acnes) is recognized as a key factor in acne development, regulating inflammatory and immune pathways. Dysbiosis has been described as the imbalance in skin microbiome homeostasis and may play a role in acne pathogenesis. Microbial interference has been shown to be a contributor to healthy skin homeostasis and staphylococcal strains may exclude acne-associated C. acnes phylotypes. In this review we present an update on the skin microbiome in acne and discuss how current acne treatments such as benzoyl peroxide, orally administered isotretinoin, and antibiotics may affect the skin microbiome homeostasis. We highlight the collateral damage of acne antibiotics on the skin microbiome, including the risk of antimicrobial resistance and the dysregulation of the microbiome equilibrium that may occur even with short-term antibiotic courses. Consequently, the interest is shifting towards new non-antibiotic pharmacological acne treatments. Orally administered spironolactone is an emerging off-label treatment for adult female patients and topical peroxisome proliferator-activated receptor gamma (PPARγ) modulation is being studied for patients with acne. The potential application of topical or oral probiotics, bacteriotherapy, and phage therapy for acne are further promising areas of future research.

A dermocosmetic regimen is able to mitigate skin sensitivity induced by a retinoid-based fixed combination treatment for acne: Results of a randomized clinical trial

INTRODUCTION

Topical retinoids cause retinoid-induced skin discomfort (RISD) mainly during the first weeks of use leading to noncompliance and premature treatment discontinuation. A dermocosmetic (DC) may help to reduce treatment-related signs and symptoms and improve adherence.

OBJECTIVES

To assess the benefit of a DC regimen compared to a routine skin care regimen (RC) by reducing RISD signs and symptoms induced by a retinoid/benzoyl peroxide fixed-drug combination in subjects with acne.

MATERIALS AND METHODS

Double-blind, randomized, comparative study in subjects ≥16 years with mild to moderate acne candidates to a topical adapalene/BPO fixed drug combination (A/BPO). Evaluations took place at Day 0, 7, 14, 28, and 84 and included erythema, desquamation, burning, itching and stinging and RISD (SD, a composite score of local treatment-related signs and symptoms and acne severity. Subjects used daily the DC or RC together with the fixed combination for 84 days.

RESULTS

Eighty-eight subjects were included, the mean age was 21 years; 84% were females. At Day 0 the SD score was 0.8 in both groups. A statistically significant difference in terms of skin sensitivity with DC compared to RC (1.6 points, vs. 2.4 points p < 0.05) was observed at Day 14. Clinical sign and symptom scores were more reduced with DC than with RC at all time points. Acne severity improved in both groups.

CONCLUSION

DC significantly reduces A/BPO-related RISD compared to RC, especially during the first 14 days of treatment, without interfering with the clinical efficacy of the treatment, thus helping to maintain treatment adherence.

Treatment of mild to severe acne with 1726 nm laser: A safe alternative to traditional acne therapies

INTRODUCTION

Acne is the most common reason for dermatology consultation in adolescents and young adults. Consultation is often delayed despite unsuccessful self-treatment. Postponing effective treatment places acne sufferers at higher risk for permanent acne scars and post-inflammatory pigment changes.

AIM

This review discusses clinical challenges with present therapeutic options for acne treatment and the role of a 1726 nm laser for acne.

METHODS

Current acne treatment guidelines were reviewed. A literature review was conducted for trials of light-based acne therapy. The selectivity of previous light-based therapies was reviewed.

RESULTS

Available acne therapy is effective, but treatment-related side effects are common. Acne treatment guidelines do not include recommendations for light-based treatments. Different types of light-based treatments have been tried but until now no wavelength specifically targeted sebaceous glands.

CONCLUSION

The 1726 nm laser is safe and effective for treating mild to severe acne in all Fitzpatrick skin types. Acne resolution is apparent within the first month and improves for up to 2 years beyond treatment.

Characteristics of Biofilm-Forming Ability and Antibiotic Resistance of Cutibacterium acnes and Staphylococcus epidermidis from Acne Vulgaris Patients

Introduction

Acne vulgaris (AV) is a common and chronic disorder of the pilosebaceous unit and has a multifactorial pathology, including activities of Cutibacterium acnes (C. acnes) and Staphylococcus epidermidis (S. epidermidis). Antibiotic resistance has become a major concern in dermatology daily practice, and the ability of biofilm formation by both bacteria is suggested to increase antibiotic resistance in acne.

Purpose

Our aim was to analyze the comparison of antibiotic resistance between biofilm-forming (BF) and non-biofilm-forming (NBF) strains of C. acnes and S. epidermidis towards seven antibiotics commonly used for acne.

Methods

This is a cross-sectional analytical study involving 60 patients with AV. Samples were obtained from closed comedones on the forehead using the standardized skin surface biopsy (SSSB) method at the Cosmetic Dermatology Clinic Dr. Hasan Sadikin in Bandung, Indonesia. Isolates were cultured and identified before undergoing the biofilm-forming test using the tissue culture plate method. Antibiotic susceptibility testing for each antibiotic was then performed using the disc diffusion method.

Results

The incidence of antibiotic resistance to clindamycin in BF and NBF C. acnes isolates was 54.5% (p=1.00), while in BF and NBF S. epidermidis isolates, it was 54.5% and 45.5% respectively (p=0.67). The incidence of antibiotic resistance to erythromycin and azithromycin in BF and NBF C. acnes isolates was 54.5% and 63.6% respectively (p=1.00), whereas for S. epidermidis BF and NBF isolates, it was 54.5% (p=1.00). There was no resistance observed to tetracycline, doxycycline, levofloxacin, and cotrimoxazole in all groups.

Conclusion

There were no significant differences in resistance against seven antibiotics between the C. acnes and S. epidermidis in BF and NBF groups. Furthermore, although statistically not significant, some resistances were observed against clindamycin, erythromycin, and azithromycin. Consequently, the use of these three antibiotics should be judiciously regulated.

Skincare potential of a sustainable postbiotic extract produced through sugarcane straw fermentation by Saccharomyces cerevisiae

Postbiotics are defined as a "preparation of inanimate microorganisms and/or their components that confers a health benefit on the host." They can be produced by fermentation, using culture media with glucose (carbon source), and lactic acid bacteria of the genus Lactobacillus, and/or yeast, mainly Saccharomyces cerevisiae as fermentative microorganisms. Postbiotics comprise different metabolites, and have important biological properties (antioxidant, anti-inflammatory, etc.), thus their cosmetic application should be considered. During this work, the postbiotics production was carried out by fermentation with sugarcane straw, as a source of carbon and phenolic compounds, and as a sustainable process to obtain bioactive extracts. For the production of postbiotics, a saccharification process was carried out with cellulase at 55°C for 24 h. Fermentation was performed sequentially after saccharification at 30°C, for 72 h, using S. cerevisiae. The cells-free extract was characterized regarding its composition, antioxidant activity, and skincare potential. Its use was safe at concentrations below ~20 mg mL-1 (extract's dry weight in deionized water) for keratinocytes and ~ 7.5 mg mL-1 for fibroblasts. It showed antioxidant activity, with ABTS IC50 of 1.88 mg mL-1 , and inhibited elastase and tyrosinase activities by 83.4% and 42.4%, respectively, at the maximum concentration tested (20 mg mL-1 ). In addition, it promoted the production of cytokeratin 14, and demonstrated anti-inflammatory activity at a concentration of 10 mg mL-1 . In the skin microbiota of human volunteers, the extract inhibited Cutibacterium acnes and the Malassezia genus. Shortly, postbiotics were successfully produced using sugarcane straw, and showed bioactive properties that potentiate their use in cosmetic/skincare products.

The World's First Acne Dysbiosis-like Model of Human 3D Ex Vivo Sebaceous Gland Colonized with Cutibacterium acnes and Staphylococcus epidermidis

Acne-prone skin is associated with dysbiosis involving Cutibacterium acnes (C. acnes) and Staphylococcus epidermidis (S. epidermidis) causing increased seborrhea in sebaceous glands (SG) and inflammation. Human primary sebocytes were cultivated using 1.106 UFC/mL C. acnes Type IA (facial acne, ATCC6919) and/or 1.105 UFC/mL S. epidermidis (unknown origin, ATCC12228) for 48 h in our SEB4GLN-optimized media without antibiotics. Bacteria and sebocytes were enumerated and assessed to determine their viability. Lipid production was imaged and quantified via Nile Red staining. SG with hair follicles were microdissected from healthy skin and cultured using 1.105 UFC/mL C. acnes Type 1A and/or 1.104 UFC/mL S. epidermidis (wild-type facial skin strain) through prior fixation and immunostaining for MC5R, C. acnes and nuclei (DAPI) via Z-stack confocal microscopy bioimaging (Leica SP5X & FIJI software, Version 2.9.0). C. acnes growth was not impacted when co-cultivated with sebocytes (2D) or SG (3D) models. Phylotype IA stimulated sebocyte lipid production, which had no impact on viability. The S. epidermidis reference strain overproliferated, inducing sebocyte mortality. For 3D SG model, culture conditions were optimized using a wild-type facial skin strain at a lower concentration, 1:10 ratio to C. acnes, reduced contact time, sequential inoculation and rinsing step. Bioimaging revealed strong C. acnes labeling in the active areas of the pilosebaceous unit. S. epidermidis formed biofilm, which was distributed across the SG via non-specific fluorescence imaging. We developed an innovative model of a sebaceous gland that mimics acne-prone skin with lipid overproduction and virulent phylotype IA C. acnes inoculation.

Natural Compounds of Fungal Origin with Antimicrobial Activity-Potential Cosmetics Applications

The phenomenon of drug resistance in micro-organisms necessitates the search for new compounds capable of combating them. Fungi emerge as a promising source of such compounds as they produce a wide range of secondary metabolites with bacteriostatic or fungistatic activity. These compounds can serve as alternatives for commonly used antibiotics. Furthermore, fungi also accumulate compounds with antiviral activity. This review focuses on filamentous fungi and macrofungi as sources of antimicrobial compounds. The article describes both individual isolated compounds and extracts that exhibit antibacterial, antifungal, and antiviral activity. These compounds are produced by the fruiting bodies and mycelium, as well as the biomass of mycelial cultures. Additionally, this review characterizes the chemical compounds extracted from mushrooms used in the realm of cosmetology; specifically, their antimicrobial activity.

Characterization of Acne-Prone Skin with Reflectance Confocal Microscopy and Optical Coherence Tomography and Modifications Induced by Topical Treatment and Probiotic Supplementation

The evaluation of acne-prone skin and absent-to-mild acne is difficult because this condition is not associated with a clinically definable situation. Previous studies showed that apparently healthy skin in patients with previous episodes of acne shows microcomedos and infundibular hyperkeratosis upon reflectance confocal microscopy (RCM) evaluation. Our aim was to characterize the subclinical and microscopic characteristics of acne-prone skin by means of RCM and dynamic optical coherence tomography (D-OCT) and evaluate microscopic changes induced by treatment. A group of 20 patients received a daily combined treatment over a period of 3 months, consisting of probiotic supplementation with three strains of 10⁹ colony-forming units of Lactobacillus (Lactobacillus reuteri, Lactobacillus casei subsp. rhamnosus, Lactobacillus plantarum) and a combined topical product of azelaic and hydroxypinacolone retinoate (HPR). Clinical evaluations and non-invasive imaging acquisitions using VISIA^® System, RCM, and D-OCT were performed at baseline, and after 4 and 12 weeks. The total number of clinically evident non-inflammatory lesions decreased during treatment from 11.5 to 7.3 (p < 0.05). There was also an evident reduction in microscopic acne features at RCM and D-OCT, such as the number of small bright follicles, large bright follicles and vascular threshold density at 300 μm and 500 μm depths. The types and extent of microscopic alterations in acne-prone skin patients may not be evident by clinical scores. Patients with low investigator global assessment (IGA) grades are a heterogeneous population, characterized by different microscopic skin features. Acne-prone skin is susceptible to treatment, and RCM and D-OCT imaging are sensitive tools to objectively monitor subclinical skin changes.

Isotretinoin treatment upregulates the expression of p53 in the skin and sebaceous glands of patients with acne vulgaris

The transcriptomic regulation induced by isotretinoin (13-cis retinoic acid) is still a matter of debate as short-term exposures of immortalized sebocytes with isotretinoin produced conflicting results. Based on translational evidence, it has been hypothesized that oral isotretinoin treatment upregulates the expression of the transcription factor p53. Twenty-five patients suffering from acne vulgaris were treated with isotretinoin (0.6 mg/kg body weight) for 6 weeks. Biopsies from back skin were taken before and after isotretinoin treatment for the determination of p53 expression by immunohistochemical staining, quantification of p53 protein concentration by enzyme-linked immunosorbent assay and TP53 gene expression by quantitative reverse transcription real time PCR. Fifteen socio-demographically cross-matched healthy volunteers served as controls. Isotretinoin treatment significantly increased the nuclear expression of p53 in sebaceous glands of treated patients compared to pre-treatment levels and p53 levels of untreated controls. Furthermore, the p53 protein and gene expression significantly increased in the skin after treatment. The magnitude of p53 expression showed an inverse correlation to acne severity score and body mass index. Under clinical conditions, isotretinoin induced the expression of p53, which controls multiple transcription factors involved in the pathogenesis of acne vulgaris including FoxO1, androgen receptor and critical genes involved in the induction of autophagy and apoptosis. Increased p53-FoxO1 signalling enhanced by systemic isotretinoin treatment explains the underlying transcriptomic changes causing sebum suppression but also the adverse effects associated with systemic isotretinoin therapy.

The bladder microbiome of NMIBC and MIBC patients revealed by 2bRAD-M

Background

Bladder cancer (BCa) is the most common malignancy of the urinary tract which can be divided into non-muscle-invasive bladder cancer (NMIBC) and muscle-invasive bladder cancer (MIBC), and their microbial differences are not fully understood. This study was conducted by performing 2bRAD sequencing for Microbiome (2bRAD-M) on NMIBC and MIBC tissue samples to investigate the microbiota differences between NMIBC and MIBC individuals.

Methods

A total of 22 patients with BCa, including 7 NMIBC and 15 MIBC, were recruited. Tumor tissues were surgically removed as samples and DNA was extracted. Type IIB restriction endonucleases were used to enzymatically cleave the microbial genome for each microbe's tag and map it to species-specific 2bRAD markers to enable qualitative and quantitative studies of microbes between MIBC and NMIBC tissues.

Results

A total of 527 species were detected. The microbial diversity of NMIBC tissues was significantly higher than that of MIBC tissues. Microbial composition of the two tumor tissues was similar, where Ralstonia_sp000620465 was the most dominant species. 4 species (Acinetobacter_guillouiae, Anoxybacillus_A_rupiensis, Brevibacillus_agri and Staphylococcus_lugdunensis) were enriched in NMIBC, while Ralstonia_mannitolilytica, Ralstonia_pickettii, and Ralstonia_sp000620465 were overrepresented in MIBC. 252 discriminatory character taxa were also revealed by linear discriminant analysis effect sizea (LEfSe). Species importance point plots identified Ralstonia_sp000620465, Cutibacterium_acnes and Ralstonia_pickettii as the three most important species between the two groups. Meanwhile, functional annotation analysis showed 3011 different COGs and 344 related signaling pathways between MIBC and NMIBC microbiome.

Conclusion

This first 2bRAD-M microbiome study on MIBC and NMIBC tissues revealed significant differences in the microbial environment between the two groups, which implies a potential association between tumor microbial dysbiosis and BCa, and provides a possible target and basis for subsequent studies on the mechanisms of BCa development and progression.

A cross-sectional study examining the prevalence of antibiotic-resistant Cutibacterium acnes isolated from patients with acne in Bangkok, Thailand

Cutibacterium acnes is associated with the pathogenesis of acne vulgaris (AV). The relationship between antibiotic-resistant C. acnes and AV remains unclear. The authors aimed to determine the prevalence of antibiotic-resistant C. acnes and investigate the association of acne severity with topical and systemic treatments in patients with acne. Samples were collected of inflammatory and noninflammatory acne, including closed and open comedones and erythematous papules/pustules from the face of patients with mild to severe acne. The samples were cultured under anaerobic conditions for the isolation of C. acnes. Antibiotic susceptibility tests for erythromycin, tetracycline, doxycycline, clindamycin, and trimethoprim/sulfamethoxazole were performed using the agar dilution method. From 153 patients, 143 viable C. acnes samples were isolated (93.5%). They were found resistant to trimethoprim/sulfamethoxazole (143/143, 100%), clindamycin (108/143, 75.5%), erythromycin (105/143, 73.4%), tetracycline (74/143, 51.7%), and doxycycline (73/143, 51.1%). There was no significant correlation between the prevalence of antibiotic resistance and acne severity. High-level resistant C. acnes correlated with higher clinical severity of acne in patients taking doxycycline (τ_b  = 0.3). The present prevalence of antibiotic-resistant C. acnes was high in Thailand. Antibiotic stewardship in AV treatment should be encouraged to prevent further antibiotic resistance crises.

Genomics of Invasive Cutibacterium acnes Isolates from Deep-Seated Infections

Cutibacterium acnes, formerly known as Propionibacterium acnes, is a commensal of the human pilosebaceous unit but also causes deep-seated infection, especially in the context of orthopedic and neurosurgical foreign materials. Interestingly, little is known about the role of specific pathogenicity factors for infection establishment. Here, 86 infection-associated and 103 commensalism-associated isolates of C. acnes were collected from three independent microbiology laboratories. We sequenced the whole genomes of the isolates for genotyping and a genome-wide association study (GWAS). We found that C. acnes subsp. acnes IA1 was the most significant phylotype among the infection isolates (48.3% of all infection isolates; odds ratio [OR] = 1.98 for infection). Among the commensal isolates, C. acnes subsp. acnes IB was the most significant phylotype (40.8% of all commensal isolates; OR = 0.5 for infection). Interestingly, C. acnes subsp. elongatum (III) was rare overall and did not occur at all in infection. The open reading frame-based GWAS (ORF-GWAS) did not show any loci with a strong signal for infection association (no P values of ≤0.05 after adjustment for multiple testing; no logarithmic OR [logOR] of ≥|2|). We concluded that all subspecies and phylotypes of C. acnes, possibly with the exception of C. acnes subsp. elongatum, are able to cause deep-seated infection given favorable conditions, most importantly related to inserted foreign material. Genetic content appears to have a small effect on the likelihood of infection establishment, and functional studies are needed to understand the individual factors contributing to deep-seated infections caused by C. acnes. IMPORTANCE Opportunistic infections emerging from human skin microbiota are of ever-increasing importance. Cutibacterium acnes, being abundant on the human skin, may cause deep-seated infections (e.g., device-associated infections). Differentiation between invasive (i.e., clinically significant) C. acnes isolates and sole contaminants is often difficult. Identification of genetic markers associated with invasiveness not only would strengthen our knowledge related to pathogenesis but also could open ways to selectively categorize invasive and contaminating isolates in the clinical microbiology lab. We show that in contrast to other opportunistic pathogens (e.g., Staphylococcus epidermidis), invasiveness is apparently a broadly distributed ability across almost all C. acnes subspecies and phylotypes. Thus, our work strongly supports an approach in which clinical significance is judged from clinical context rather than by detecting specific genetic traits.

Comparative Evaluation of Existing and Rationally Designed Novel Antimicrobial Peptides for Treatment of Skin and Soft Tissue Infections

Skin and soft tissue infections (SSTIs) and acne are among the most common skin conditions in primary care. SSTIs caused by ESKAPE pathogens (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter sp.) can range in severity, and treating them is becoming increasingly challenging due to the growing number of antibiotic-resistant pathogens. There is also a rise in antibiotic-resistant strains of Cutibacterium acne, which plays a role in the development of acne. Antimicrobial peptides (AMPs) are considered to be a promising solution to the challenges posed by antibiotic resistance. In this study, six new AMPs were rationally designed and compared to five existing peptides. The MIC values against E. coli, P. aeruginosa, K. pneumoniae, E. faecium, S. aureus, and C. acnes were determined, and the peptides were evaluated for cytotoxicity using Balb/c 3T3 cells and dermal fibroblasts, as well as for hemolytic activity. The interaction with bacterial membranes and the effect on TNF-α and IL-10 secretion were also evaluated for selected peptides. Of the tested peptides, RP556 showed high broad-spectrum antibacterial activity without inducing cytotoxicity or hemolysis, and it stimulated the production of IL-10 in LPS-stimulated peripheral blood mononuclear cells. Four of the novel AMPs showed pronounced specificity against C. acnes, with MIC values (0.3–0.5 μg/mL) below the concentrations that were cytotoxic or hemolytic.

Characterization of a live Cutibacterium acnes subspecies defendens strain XYCM42 and clinical assessment as a topical regimen for general skin health and cosmesis

BACKGROUND

When formulating topical products to treat skin diseases and addressing general skin health and cosmesis, most of the focus has traditionally been placed on how any given ingredient may impact the structure, function, and health of human skin elements. However, recent research is beginning to highlight the importance of the skin microbiome in relation to certain skin conditions and general cosmesis. Cutibacterium acnes is one of the most prolific skin-specific bacterial species. Research has shown that the species is divided into subspecies, some of which are thought to be beneficial to the skin. This paper aims to determine the efficacy of strainXYCM42, a C. acnes subspecies defendens derived strain designed to improve the health and appearance of the skin.

METHODS

In vitro studies were performed on human keratinocyte and fibroblast monolayers, human peripheral blood mononuclear cells (PBMC), and skin explants to elucidate the effects of live XYCM42 cells and their ferment on human skin cells and tissues. Subsequently, clinical studies were performed using XYCM42-based topical regimens designed to deliver and support the engraftment of live XYCM42 cells onto subjects' skin. Two studies were performed, a 3-week pilot study (n = 10) and a 8-week pivotal study (n = 121). In the latter, 32 subjects were enrolled for an in-clinic portion for efficacy evaluation, with clinic visits occurring at Baseline, Week 1, Week 4, and Week 8.

RESULTS

In vitro data suggest that XYCM42 and its ferment filtrate have potential to provide benefits to the skin via antioxidant, anti-inflammatory, and select antimicrobial activities. Clinical observation demonstrated that a XYCM42-containing regimen supports a healthy skin environment, promotes increased skin hydration, decreases erythema, calms the skin, and regulates sebum production.

CONCLUSION

These studies provide further evidence that specific strains of C. acnes, such as XYCM42, have a more beneficial function regarding skin health and appearance than was previously thought. Appropriate use of formulations derived from symbiotic strains within the skin microbiome can support the development of novel, beneficial topicals.

A Comparative Study on Adipose-Derived Mesenchymal Stem Cells Secretome Delivery Using Microneedling and Fractional CO2 Laser for Facial Skin Rejuvenation

Background

The efficacy of adipose-derived mesenchymal stem cells (ADMSCs) secretome for skin aging has been established, yet no studies hitherto directly investigated the best administration method for such purpose.

Purpose

We aimed to compare microneedling (MN) versus fractional CO₂ laser (FL) as methods of delivery for ADMSCs secretome in the treatment of aging skin.

Patients and Methods

A single-blind, randomized split-face clinical trial was conducted on 30 Indonesian women (aged 35-59 years old) with signs of facial cutaneous senescence. Their initial aging status was assessed by dermoscopy photoaging scale (DPAS) and Janus-III measurement system. In the second and fourth weeks, all participants were treated with both MN and FL, followed by the application of a four-fold concentrated ADMSC secretome. The assignment of which side of the face received MN or FL was done by computer-based randomization. Skin parameters were reevaluated on the fourth and sixth weeks, along with patient satisfaction, level of comfort, preference for administration techniques, and also adverse events experienced during the study. Appropriate statistical analyses were subsequently performed at a significance level of 0.05.

Results

Significant improvements in total DPAS and wrinkles were found in the MN and FL groups at the end of the trial. In contrast, no statistical differences in all parameters were observed between groups in the fourth and sixth weeks. FL scored higher than MN for satisfaction and preference, but lower in terms of comfort. Pain, burning sensation, and itch were the side effects experienced by subjects upon treatment. Two patients had prolonged reddish skin succeeding FL treatment, which relieved with moisturizer application.

Conclusion

Both MN and FL yielded comparable results for improving several skin aging features. However, subjective preference for ADMSCs secretome administration method may differ when considering satisfaction, comfort, and possible adverse events.

Bio-Based Nano-Enabled Cosmetic Formulations for the Treatment of Cutibacterium acnes-Associated Skin Infections

Acne is a common chronic skin condition with serious physical and psychosocial consequences. In some cases, the appearance of pimples, whiteheads, or blackheads on the face, neck, and back may lead to scarring, disfiguring, depression, frustration, and anxiety in patients. Current treatments rely on antibiotics to eradicate Cutibacterium acnes (C. acnes), the bacterium responsible for this skin condition. However, these approaches do not scavenge the reactive oxidative species (ROS) generated during disease development and raise concerns about the increase in antimicrobial resistance. In this study, an environmentally friendly and cost-effective self-assembly nanoencapsulation technology based on zein, a bio-based hydrophobic protein, was employed to produce multifunctional essential oil (EO)-loaded nanocapsules (NCs) with superior antioxidant and bactericidal activity toward C. acnes. The NCs displayed "smart" release of the active cargo only under the conditions that were conducive to acne proliferation on skin. Once incorporated into creams, the EO-loaded NCs led to a complete inhibition of C. acnes and demonstrated the capacity to scavenge ROS, thus preventing damage to human skin cells. The in vitro permeation studies revealed that the nanoformulated EO was able to penetrate through the epidermis, indicating its potential for the treatment of skin diseases, such as acne.

Therapeutic properties and pharmacological activities of asiaticoside and madecassoside: A review

Centella asiatica is an ethnomedicinal herbaceous species that grows abundantly in tropical and sub-tropical regions of China, India, South-Eastern Asia and Africa. It is a popular nutraceutical that is employed in various forms of clinical and cosmetic treatments. C. asiatica extracts are reported widely in Ayurvedic and Chinese traditional medicine to boost memory, prevent cognitive deficits and improve brain functions. The major bioactive constituents of C. asiatica are the pentacyclic triterpenoid glycosides, asiaticoside and madecassoside, and their corresponding aglycones, asiatic acid and madecassic acid. Asiaticoside and madecassoside have been identified as the marker compounds of C. asiatica in the Chinese Pharmacopoeia and these triterpene compounds offer a wide range of pharmacological properties, including neuroprotective, cardioprotective, hepatoprotective, wound healing, anti-inflammatory, anti-oxidant, anti-allergic, anti-depressant, anxiolytic, antifibrotic, antibacterial, anti-arthritic, anti-tumour and immunomodulatory activities. Asiaticoside and madecassoside are also used extensively in treating skin abnormalities, burn injuries, ischaemia, ulcers, asthma, lupus, psoriasis and scleroderma. Besides medicinal applications, these phytocompounds are considered cosmetically beneficial for their role in anti-ageing, skin hydration, collagen synthesis, UV protection and curing scars. Existing reports and experimental studies on these compounds between 2005 and 2022 have been selectively reviewed in this article to provide a comprehensive overview of the numerous therapeutic advantages of asiaticoside and madecassoside and their potential roles in the medical future.

Topical application of bacteriocins from Bacillus subtilis promotes Staphylococcus aureus decolonization in acneic skin and improves the clinical appearance of mild-to-moderate acne

Introduction

Patients with mild-to-moderate acne are frequently colonized by Staphylococcus aureus on their skin, which alters microenvironmental skin conditions and exacerbates disease symptoms. Bacteriocins produced by Bacillus subtilis may act as antimicrobial peptides against Gram-positive bacteria.

Aim

To investigate whether topical application of bacteriocins from B. subtilis could serve as a potential strategy for promoting S. aureus decolonization from acneic skin.

Material and methods

The research product was a cream formulation containing 1% bacteriocins from B. subtilis. First, we conducted a 60-day pilot study on the effect of topically applied bacteriocins from B. subtilis on the absolute abundance of S. aureus in 12 patients with mild-to-moderate acne. Second, we designed an 8-week, uncontrolled, open-label, multicentre clinical study to investigate whether the topical application of bacteriocins from B. subtilis reduces the number of inflammatory and non-inflammatory lesions, as well as Global Acne Grading Scale (GAGS) scores, in 373 patients with mild-to-moderate acne.

Results

At the microbiological level, quantitative PCR showed a decrease in the absolute abundance of S. aureus in acne areas after topical application of the research product for 60 days (-38%, p < 0.001). In the clinical study, the number of inflammatory and non-inflammatory lesions was found to decrease at 8 weeks by 59% (p < 0.001) and 58% (p < 0.001), respectively, compared with baseline. A 56% decrease was observed for GAGS scores.

Conclusions

Topical bacteriocins from B. subtilis can promote S. aureus decolonization in acneic skin, ultimately improving the clinical appearance of mild-to-moderate acne.

Viaminate Inhibits Propionibacterium Acnes-induced Abnormal Proliferation and Keratinization of HaCat Cells by Regulating the S100A8/S100A9- MAPK Cascade

BACKGROUND

Viaminate, a vitamin A acid drug developed in China, has been clinically used in acne treatment to regulate epithelial cell differentiation and proliferation, inhibit keratinization, reduce sebum secretion, and control immunological and anti-inflammatory actions; however, the exact method by which it works is unknown.

METHODS

In the present study, acne was induced in the ears of rats using Propionibacterium acnes combined with sebum application.

RESULTS

After 30 days of treatment with viaminate, the symptoms of epidermal thickening and keratin overproduction in the ears of rats were significantly improved. Transcriptomic analysis of rat skin tissues suggested that viaminate significantly regulated the biological pathways of cellular keratinization. Gene differential analysis revealed that the S100A8 and S100A9 genes were significantly downregulated after viaminate treatment. The results of qPCR and Western blotting confirmed that viaminate inhibited the expression of S100A8 and S100A9 genes and proteins in rat and HaCat cell acne models, while its downstream pathway MAPK (MAPK p38/JNK/ERK1/2) protein expression levels were suppressed. Additional administration of the S100A8 and S100A9 complex protein significantly reversed the inhibitory effect of viaminate on abnormal proliferation and keratinization levels in acne cell models.

CONCLUSION

In summary, viaminate can improve acne by modulating S100A8 and S100A9 to inhibit MAPK pathway activation and inhibit keratinocyte proliferation and keratinization levels.

THE EFFECT OF RUTA GRAVEOLENS L. ETHANOLIC EXTRACTS ON SKIN ISOLATES OF STAPHYLOCOCCI AND PROPIONIBACTERIUM ACNES

OBJECTIVE

The aim: To define antimicrobial properties of 50%, 70% and 90% ethanolic extracts of Ruta graveolens L. against macrolide resistant (MLS-resistant) skin isolates of staphylococci and Propionibacterium acnes, and to determine MIC and MBC of investigated extracts.

PATIENTS AND METHODS

Materials and methods: Extracts were prepared by the method of maceration. Bacterial cultures were identified by biochemical microtests. Identification of MLS-resistance type was performed by using disc-diffusion method. The MIC and MBC were determined by serial two-fold dilution of ethanolic extracts of Ruta graveolens L. in MHB and HBB for staphylococci and P. acnes, respectively. Bacterial growth in each well was assayed by absorption at 495 nm, using a spectrophotometer SynergyTMHTX S1LFTA (BioTek Instruments, Inc., USA).

RESULTS

Results: All ethanolic extracts of garden ruta were active against all staphylococci and P. acnes skin isolates and showed exclusively bactericidal activity (MBC/MIC ratios ranged from 1 to 2) against all investigated strains. 90% extract of Ruta graveolens L. showed better results than 50% and 70% extracts - average MIC and MBC concentations for P. acnes strains were 1.38«0.66 mg/mL and for staphylococcal strains average MIC was 2.1«1.16 mg/mL and MBC - 2.86«1.2 mg/mL.

CONCLUSION

Conclusions: 50%, 70% and 90% ethanolic garden ruta extracts showed moderate antibacterial activity against main skin pathogens, responsible for acnes vulgaris development - S. epidermidis, S. aureus and P. acnes. No difference in susceptibility between resistance and sensitive strains of staphylococci and P. acnes indicate that acquired MLS-resistance of investigated skin isolates does not affect on the level of their sensitivity to ruta extracts.

Antibiotics and Antimicrobial Resistance in Acne: Epidemiological Trends and Clinical Practice Considerations

Antimicrobial resistance is an increasing public health problem worldwide. The interest of a focus on antimicrobial resistance in acne lies on the facts that acne vulgaris (acne) is the most common skin disease worldwide, that the bacterium Cutibacterium acnes (C. acnes, formerly Propionibacterium acnes) plays a key role in the pathogenesis of acne, while at the same time being part of the skin flora, and that antibiotics are commonly recommended for acne treatment. The overuse of topical and/or systemic antibiotics, the long treatment courses used for acne, and the availability of over-the-counter antibiotic preparations, have led to the worldwide emergence of resistant strains in acne patients. In this review, we discuss the epidemiological trends of antimicrobial resistance in acne, the need to avoid the perturbation of the skin microbiome caused by anti-acne antibiotics, and the clinical practice considerations related to the emergence of resistant strains in acne patients. In light of the increasing risk of antimicrobial resistance, raising concerns over the misuse of antibiotics, prescribing patterns can be a critical target for antibiotic stewardship efforts. Also, the selection of non-antibiotic therapies for acne, whenever possible, may offer significant advantages.

Molecular Diversity and Biochemical Content in Two Invasive Alien Species: Looking for Chemical Similarities and Bioactivities

The biochemical composition, molecular diversity, and two different bioactivities of Asparagopsis armata and Rugulopteryx okamurae (two alien species with different invasive patterns in the southern Iberian Peninsula) were analyzed through spectrophotometric methods and Fourier transform ion cyclotron mass spectroscopy (FT-ICR-MS). A total of 3042 molecular formulas were identified from the different extracts. The dH2O extracts were the most molecularly different. A. armata presented the highest content of nitrogenous compounds (proteins, CHON) and sulphur content, whereas R. okamurae was rich in carbonated compounds (total carbon, lipids, CHO, and CHOP). Antioxidant capacity and phenolic content were higher in R. okamurae than in A. armata. Antimicrobial activity was detected from both species. A. armata showed capacity to inhibit human and fish pathogens (e.g., Staphylococcus aureus or Vibrio anguillarum), whereas R. okamurae only showed inhibition against human bacteria (Staphylococcus aureus and Cutibacterium acnes). In R. okamurae, molecules with a great number of pharmaceutical activities (e.g., anti-inflammatory or antitumoral), antibacterial, biomaterial, and other utilities were found. The main molecules of A. armata had also pharmaceutical applications (e.g., antimalarian, antithrombotic, anti-inflammatory, or antiarthritis). The valorization of these species can help to counteract the environmental effects of the bioinvasions.

Acne Vulgaris, Atopic Dermatitis and Rosacea: The Role of the Skin Microbiota-A Review

The skin harbors a huge number of different microorganisms such as bacteria, fungi and viruses, and it acts as a protective shield to prevent the invasion of pathogens and to maintain the health of the commensal microbiota. Several studies, in fact, have shown the importance of the skin microbiota for healthy skin. However, this balance can be altered by intrinsic and extrinsic factors, leading to the development of skin disease, such as acne vulgaris (AV), atopic dermatitis (AD) and rosacea(RS). Although these diseases are widespread and affect both adolescents and adults, the scientific correlation between these disorders and the skin microbiota and physiological parameters (TEWL, hydration and lipid composition) is still unclear. This review aims to investigate the current literature regarding the correlation between the skin microbiota and its imbalance underlying microbiological aspects, how the skin microbiota changes over the course of the disease and the current possible treatments. The following reported studies show a general imbalance of the bacterial flora. For this reason, more in-depth studies are necessary to explore the different subspecies and strains involved in all three diseases.

In Vitro Antibacterial and Anti-Inflammatory Activity of Arctostaphylos uva-ursi Leaf Extract against Cutibacterium acnes

Cutibacterium acnes (C. acnes) is the main causative agent of acne vulgaris. The study aims to evaluate the antimicrobial activity of a natural product, Arctostaphylos uva-ursi leaf extract, against C. acnes. Preliminary chemical–physical characterization of the extract was carried out by means of FT-IR, TGA and XPS analyses. Skin permeation kinetics of the extract conveyed by a toning lotion was studied in vitro by Franz diffusion cell, monitoring the permeated arbutin (as the target component of the extract) and the total phenols by HPLC and UV-visible spectrophotometry, respectively. Antimicrobial activity and time-killing assays were performed to evaluate the effects of Arctostaphylos uva-ursi leaf extract against planktonic C. acnes. The influence of different Arctostaphylos uva-ursi leaf extract concentrations on the biofilm biomass inhibition and degradation was evaluated by the crystal violet (CV) method. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) test was used to determine the viability of immortalized human keratinocytes (HaCaT) after exposure to Arctostaphylos uva-ursi leaf extract for 24 and 48 h. Levels of interleukin (IL)-1β, IL-6, IL-8 and tumour necrosis factor (TNF)-α were quantified after HaCaT cells cotreatment with Arctostaphylos uva-ursi leaf extract and heat-killed C. acnes. The minimum inhibitory concentration (MIC) which exerted a bacteriostatic action on 90% of planktonic C. acnes (MIC₉₀) was 0.6 mg/mL. Furthermore, MIC and sub-MIC concentrations influenced the biofilm formation phases, recording a percentage of inhibition that exceeded 50 and 40% at 0.6 and 0.3 mg/mL. Arctostaphylos uva-ursi leaf extract disrupted biofilm biomass of 57 and 45% at the same concentrations mentioned above. Active Arctostaphylos uva-ursi leaf extract doses did not affect the viability of HaCaT cells. On the other hand, at 1.25 and 0.6 mg/mL, complete inhibition of the secretion of pro-inflammatory cytokines was recorded. Taken together, these results indicate that Arctostaphylos uva-ursi leaf extract could represent a natural product to counter the virulence of C. acnes, representing a new alternative therapeutic option for the treatment of acne vulgaris.

Honokiol Improves Acne-like Lesions in a Rabbit Ear Model by Alleviating Hyperkeratosis and Sebum Secretion

The prevalence of acne vulgaris is high, but the topical retinoids used as the foundation of treatment have teratogenic and photosensitivity properties. Previous studies have suggested that honokiol, a small-molecule compound extracted from Magnolia officinalis, could effectively inhibit Cutibacterium acnes ( C acnes) and inflammation in vitro. However, the effect in vivo is unclear. The rabbit ear acne model that we created showed obvious comedones and hyperkeratosis. These lesions were repeatedly measured and recorded by dermatoscopy (ultraviolet light). Compared with the control group, topical 2.5% honokiol cream obviously improved the comedones and hyperkeratosis and effectively reduced sebum secretion, as shown by Oil Red O staining. The effects were equivalent to those of adapalene gel without local side effects. We added honokiol's other functions to acne treatment in addition to antiinflammation, but further studies are needed.

Genetic determinants of antimicrobial resistance in three multi-drug resistant strains of Cutibacterium acnes isolated from patients with acne: a predictive in silico study

Objectives. Using available whole genome data, the objective of this in silico study was to identify genetic mechanisms that could explain the antimicrobial resistance profile of three multi-drug resistant (MDR) strains (CA17, CA51, CA39) of the skin bacterium Cutibacterium acnes previously recovered from patients with acne. In particular, we were interested in detecting novel genetic determinants associated with resistance to fluoroquinolone and macrolide antibiotics that could then be confirmed experimentally.

Methods. A range of open source bioinformatics tools were used to ‘mine’ genetic determinants of antimicrobial resistance and plasmid borne contigs, and to characterise the phylogenetic diversity of the MDR strains.

Results. As probable mechanisms of resistance to fluoroquinolones, we identified a previously described resistance associated allelic variant of the gyrA gene with a ‘deleterious' S101L mutation in type IA1 strains CA51 (ST1) and CA39 (ST1), as well as a novel E761R ‘deleterious’ mutation in the type II strain CA17 (ST153). A distinct genomic sequence of the efflux protein YfmO which is potentially associated with resistance to MLSB antibiotics was also present in CA17; homologues in CA51, CA39, and other strains of Cutibacterium acnes , were also found but differed in amino acid content. Strikingly, in CA17 we also identified a circular 2.7 kb non-conjugative plasmid (designated pCA17) that closely resembled a 4.8 kb plasmid (pYU39) from the MDR Salmonella enterica strain YU39.

Conclusions. This study has provided a detailed explanation of potential genetic determinants for MDR in the Cutibacterium acnes strains CA17, CA39 and CA51. Further laboratory investigations will be required to validate these in silico results, especially in relation to pCA17.

Prostate Infiltration by Treg and Th17 Cells as an Immune Response to Propionibacterium acnes Infection in the Course of Benign Prostatic Hyperplasia and Prostate Cancer

Benign prostatic hyperplasia (BPH) and prostate cancer (PCa) belong to the most frequent diseases in ageing men. It has been proposed that prostate chronic inflammation is a risk factor for the development of both BPH and PCa. However, potential stimuli that cause or maintain inflammation in the prostate gland are still poorly characterized. Bacterial infections seems to be one of the potential sources of prostatitis. Recent studies show that Propionibacterium acnes (P. acnes) is the most prevalent microorganism in the prostate gland and may be a predisposing factor for inflammation of prostatic tissue. It indicates that P. acnes may contribute to cancer development by enhancing proinflammatory responses, as well as by modifying the prostate extracellular environment. In this review, we discuss the potential role of P. acnes in the development of BPH and PCa and highlight the importance of regulatory T CD4(+)FoxP3(+) (Treg) and Th17 cells in response to P. acnes infection in the context of both prostate diseases.

Anti-Inflammatory microRNAs for Treating Inflammatory Skin Diseases

Skin inflammation occurs due to immune dysregulation because of internal disorders, infections, and allergic reactions. The inflammation of the skin is a major sign of chronic autoimmune inflammatory diseases, such as psoriasis, atopic dermatitis (AD), and lupus erythematosus. Although there are many therapies for treating these cutaneous inflammation diseases, their recurrence rates are high due to incomplete resolution. MicroRNA (miRNA) plays a critical role in skin inflammation by regulating the expression of protein-coding genes at the posttranscriptional level during pathogenesis and homeostasis maintenance. Some miRNAs possess anti-inflammatory features, which are beneficial for mitigating the inflammatory response. miRNAs that are reduced in inflammatory skin diseases can be supplied transiently using miRNA mimics and agomir. miRNA-based therapies that can target multiple genes in a given pathway are potential candidates for the treatment of skin inflammation. This review article offers an overview of the function of miRNA in skin inflammation regulation, with a focus on psoriasis, AD, and cutaneous wounds. Some bioactive molecules can target and modulate miRNAs to achieve the objective of inflammation suppression. This review also reports the anti-inflammatory efficacy of these molecules through modulating miRNA expression. The main limitations of miRNA-based therapies are rapid biodegradation and poor skin and cell penetration. Consideration was given to improving these drawbacks using the approaches of cell-penetrating peptides (CPPs), nanocarriers, exosomes, and low-frequency ultrasound. A formulation design for successful miRNA delivery into skin and target cells is also described in this review. The possible use of miRNAs as biomarkers and therapeutic modalities could open a novel opportunity for the diagnosis and treatment of inflammation-associated skin diseases.

Genomic and Phenotypic Characterization of Cutibacterium acnes Bacteriophages Isolated from Acne Patients

Cutibacterium acnes is a pathogen that can cause acne vulgaris, sarcoidosis, endodontic lesions, eye infections, prosthetic joint infections, and prostate cancer. Recently, bacteriophage (phage) therapy has been developed as an alternative to antibiotics. In this study, we attempted to isolate 15 phages specific to C. acnes from 64 clinical samples obtained from patients with acne vulgaris. Furthermore, we sequenced the genomes of these three phages. Bioinformatic analysis revealed that the capsid and tape measure proteins are strongly hydrophobic. To efficiently solubilize the phage particles, we measured the adsorption rate, one-step growth curve, and phage stability using an SMT2 buffer containing Tween 20. Here, we report the genotypic and phenotypic characteristics of the novel C. acnes-specific phages.

Targeting Acne Bacteria and Wound Healing In Vitro Using Plectranthus aliciae, Rosmarinic Acid, and Tetracycline Gold Nanoparticles

Gold nanoparticles from plant extracts and their bioactive compounds to treat various maladies have become an area of interest to many researchers. Acne vulgaris is an inflammatory disease of the pilosebaceous unit caused by the opportunistic bacteria Cutibacterium acnes and Staphylococcus epidermis. These bacteria are not only associated with inflammatory acne but also with prosthetic-implant-associated infections and wounds. Studies have hypothesised that these bacteria have a mutualistic relationship and act as a multispecies system. It is believed that these bacteria form a multispecies biofilm under various conditions and that these biofilms contribute to increased antibiotic resistance compared to single-species biofilms. This study aimed to investigate the antibacterial and wound healing potential of synthesised gold nanoparticles (AuNP_s) from an endemic South African plant, Plectranthus aliciae (AuNP_PAE), its major compound rosmarinic acid (AuNP_RA) and a widely used antibiotic, tetracycline (AuNP_TET). Synthesised gold nanoparticles were successfully formed and characterised using ultraviolet–visible spectroscopy (UV–vis), dynamic light scattering (DLS), Fourier transform infrared spectroscopy (FTIR), zeta potential (ζ-potential), high-resolution transmission electron microscopy (HRTEM), and selected area electron diffraction (SAED), and they were investigated for stability under various biological conditions. Stable nanoparticles were formed with ζ-potentials of −18.07 ± 0.95 mV (AuNP_PAE), −21.5 ± 2.66 mV (AuNP_RA), and −39.83 ± 1.6 mV (AuNP_TET). The average diameter of the AuNP_s was 71.26 ± 0.44 nm, 29.88 ± 3.30 nm, and 132.6 ± 99.5 nm for AuNP_PAE, AuNP_RA, and AuNP_TET, respectively. In vitro, biological studies confirmed that although no antibacterial activity or biofilm inhibition was observed for the nanoparticles tested on the multispecies C. acnes and S. epidermis systems, these samples had potential wound closure activity. Gold nanoparticles formed with rosmarinic acid significantly increased wound closure by 21.4% at 25% v/v (≈29.2 µg/mL) compared to the negative cell control and the rosmarinic acid compound at the highest concentration tested of 500 µg/mL. This study concluded that green synthesised gold nanoparticles of rosmarinic acid could potentially be used for treating wounds.

The immunomodulatory potential of phage therapy to treat acne: a review on bacterial lysis and immunomodulation

Background

Characterized by an inflammatory pathogenesis, acne is the most common skin disorder worldwide. Altered sebum production, abnormal proliferation of keratinocytes, and microbiota dysbiosis represented by disbalance in Cutibacterium acnes population structure, have a synergic effect on inflammation of acne-compromised skin. Although the role of C. acnes as a single factor in acne development is still under debate, it is known that skin and skin-resident immune cells recognize this bacterium and produce inflammatory markers as a result. Control of the inflammatory response is frequently the target for acne treatment, using diverse chemical or physical agents including antibiotics. However, some of these treatments have side effects that compromise patient adherence and drug safety and in the case of antibiotics, it has been reported C. acnes resistance to these molecules. Phage therapy is an alternative to treat antibiotic-resistant bacterial strains and have been recently proposed as an immunomodulatory therapy. Here, we explore this perspective about phage therapy for acne, considering the potential immunomodulatory role of phages.

Methodology

Literature review was performed using four different databases (Europe PubMed Central-ePMC, Google Scholar, PubMed, and ScienceDirect). Articles were ordered and selected according to their year of publication, number of citations, and quartile of the publishing journal.

Results

The use of lytic bacteriophages to control bacterial infections has proven its promising results, and anti-inflammatory effects have been found for some bacteriophages and phage therapy. These effects can be related to bacterial elimination or direct interaction with immune cells that result in the regulation of pro-inflammatory cytokines. Studies on C. acnes bacteriophages have investigated their lytic activity, genomic structure, and stability on different matrices. However, studies exploring the potential of immunomodulation of these bacteriophages are still scarce.

Conclusions

C. acnes bacteriophages, as well as other phages, may have direct immunomodulatory effects that are yet to be fully elucidated. To our knowledge, to the date that this review was written, there are only two studies that investigate anti-inflammatory properties for C. acnes bacteriophages. In those studies, it has been evidenced reduction of pro-inflammatory response to C. acnes inoculation in mice after bacteriophage application. Nevertheless, these studies were conducted in mice, and the interaction with the immune response was not described. Phage therapy to treat acne can be a suitable therapeutic alternative to C. acnes control, which in turn can aid to restore the skin's balance of microbiota. By controlling C. acnes colonization, C. acnes bacteriophages can reduce inflammatory reactions triggered by this bacterium.

Marine Actinobacteria a New Source of Antibacterial Metabolites to Treat Acne Vulgaris Disease—A Systematic Literature Review

Acne vulgaris is a multifactorial disease that remains under-explored; up to date it is known that the bacterium Cutibacterium acnes is involved in the disease occurrence, also associated with a microbial dysbiosis. Antibiotics have become a mainstay treatment generating the emergence of antibiotic-resistant bacteria. In addition, there are some reported side effects of alternative treatments, which indicate the need to investigate a different therapeutic approach. Natural products continue to be an excellent option, especially those extracted from actinobacteria, which represent a prominent source of metabolites with a wide range of biological activities, particularly the marine actinobacteria, which have been less studied than their terrestrial counterparts. Therefore, this systematic review aimed to identify and evaluate the potential anti-infective activity of metabolites isolated from marine actinobacteria strains against bacteria related to the development of acne vulgaris disease. It was found that there is a variety of compounds with anti-infective activity against Staphylococcus aureus and Staphylococcus epidermidis, bacteria closely related to acne vulgaris development; nevertheless, there is no report of a compound with antibacterial activity or quorum-sensing inhibition toward C. acnes, which is a surprising result. Since two of the most widely used antibiotics for the treatment of acne targeting C. acnes were obtained from actinobacteria of the genus Streptomyces, this demonstrates a great opportunity to pursue further studies in this field, considering the potential of marine actinobacteria to produce new anti-infective compounds.