The effect of different antibiotic combinations in calcium sulfate cement on the growth of Cutibacterium acnes and Staphylococcus periprosthetic shoulder infection isolates.

BACKGROUND: Periprosthetic joint infections (PJI) of the shoulder are a devastating complication of shoulder arthroplasty and are commonly caused by Staphylococcus and Cutibacterium acnes. Absorbable calcium sulfate (CS) beads are sometimes used for delivering antibiotics in PJI. This study evaluates the in vitro effect of different combinations of gentamicin, vancomycin, and ertapenem in beads made from CS cement on the growth of C acnes and coagulase-negative Staphylococcus (CNS) strains. METHODS: Three strains of C acnes and 5 strains of CNS from clinically proven shoulder PJI were cultured and plated with CS beads containing combinations of vancomycin, gentamicin, and ertapenem. Plates with C acnes were incubated anaerobically while plates with Staphylococcus were incubated aerobically at 37 °C. Zones of inhibition were measured at intervals of 3 and 7 days using a modified Kirby Bauer technique, and beads were moved to plates containing freshly streaked bacteria every seventh day. This process was run in triplicate over the course of 56 days. Statistical analysis was conducted using SPSS v. 28 with repeated measures analysis of variance (ANOVA) and pairwise comparisons with Tukey correction. RESULTS: In experiments with C acnes, beads containing ertapenem + vancomycin and vancomycin alone formed the largest zones of inhibition over time (P < .001). In experiments with Staphylococcus, beads containing vancomycin alone formed the largest zones of inhibition over time for all 5 strains (P < .001). Zones of inhibition were 1.4x larger for C acnes than for Staphylococcus with beads containing vancomycin alone. For both C acnes and Staphylococcus, beads containing ertapenem had the strongest initial effect, preventing all bacterial growth in C acnes and almost all growth for Staphylococcus during the first week but dropping substantially by the second week. Beads containing gentamicin alone consistently created smaller zones of inhibition than beads containing vancomycin alone, with vancomycin producing zones 5.3x larger than gentamicin in C acnes and 1.3x larger in Staphylococcus (P < .001). DISCUSSION: These data suggest that for both C acnes and Staphylococcal species, CS beads impregnated with vancomycin were most effective at producing a robust antibiotic effect. Additionally, ertapenem may be a viable supplement in order to create a more potent initial antibiotic effect but is not as effective as vancomycin when used alone. Gentamicin alone was not effective in maintaining consistent and long-term antibiotic effects. These results indicate that amongst the antibiotics currently commercially available to be used with CS, vancomycin is consistently superior to gentamicin in the setting of C. acnes and CNS.

Are antibiotics still relevant in acne? A review of the therapeutic conundrum.

Antibiotics have constituted the mainstay of acne therapy despite acne being classified as an inflammatory disorder. The indiscriminate usage of antibiotics over the years has thus fueled the issue of antimicrobial resistance. Cutibacterium acnes (C. acnes) can acquire resistance due to chromosomal mutation or genetic acquisition. C. acnes can transfer resistance to other resident flora, complicating the management of skin and soft tissue infections. It can also transfer resistant strains to other body sites and to immunocompromised and elderly patients thus putting them at risk of serious infections. Recent studies have highlighted the physiologic role of C. acnes in maintaining the normal homeostasis of the skin microbiome. The role of Malassezia in causation of acne has piqued interest in recent times. The efficacy of antibiotics in acne is attributed to their para-antibiotic, anti-inflammatory action rather than antimicrobial action. Thus, usage of low-dose antibiotics and alternatives to antibiotics has been advocated. Some alternative therapies showing efficacy in acne are probiotics, oral zinc, precision therapy using succinic acid, bacteriophages, and anti-biofilm therapy like myrtacin, topical azelaic acid, and salicylic acid. Using isotretinoin in early stages of acne can reduce the incidence of scarring and alleviate the need for antibiotics. Thus, a gradual shift from antibiotics to alternative therapies in acne is the need of the hour.

Utilizing the photodynamic properties of curcumin to disrupt biofilms in Cutibacterium acnes: A promising approach for treating acne.

BACKGROUND: The treatment of acne vulgaris is often challenging due to the antibiotic resistance frequently observed in Cutibacterium acnes (C.acnes), a prevalent bacterium linked to this condition. OBJECTIVE: The objective of this research was to examine the impact of curcumin photodynamic therapy (PDT) on the survival of C.acnes and activity of biofilms produced by this microorganism. METHODS: Following the Clinical and Laboratory Standards Institute (CLSI) guidelines, we assessed the drug sensitivity of 25 clinical C.acnes strains to five antibiotics (erythromycin, clindamycin, tetracycline, doxycycline, minocycline) and curcumin by implementing the broth microdilution technique. In addition, we established C.acnes biofilms in a laboratory setting and subjected them to curcumin-PDT(curcumin combined with blue light of 180 J/cm2). Afterwards, we evaluated their viability using the XTT assay and observed them using confocal laser scanning microscopy. RESULTS: The result revealed varying resistance rates among the tested antibiotics and curcumin, with erythromycin, clindamycin, tetracycline, doxycycline, minocycline, and curcumin exhibiting resistance rates of 72 %, 44 %, 36 %, 28 %, 0 %, and 100 %, respectively. In the curcumin-PDT inhibition tests against four representative antibiotic-resistant strains, it was found that the survival rate of all strains of planktonic C. acnes was reduced, and the higher the concentration of curcumin, the lower the survival rate. Furthermore, in the biofilm inhibition tests, the vitality and three-dimensional structure of the biofilms were disrupted, and the inhibitory effect became more significant with higher concentrations of curcumin. CONCLUSION: The results emphasize the possibility of using curcumin PDT as an alternative approach for the treatment of C.acnes, especially in instances of antibiotic-resistant variations and infections related to biofilms.

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.

A Bioactive Compound-Loaded Zinc-Aminoclay Encapsulated, Pickering Emulsion System for Treating Acne-Inducing Microbes.

Acne is a common skin condition caused by the growth of certain bacteria. Many plant extracts have been investigated for their potential to combat acne-inducing microbes, and one such plant extract is microwave-assisted Opuntia humifusa extract (MA-OHE). The MA-OHE was loaded onto zinc-aminoclay (ZnAC) and encapsulated in a Pickering emulsion system (MA-OHE/ZnAC PE) to evaluate its therapeutic potential against acne-inducing microbes. Dynamic light scattering and scanning electron microscopy were used to characterize MA-OHE/ZnAC PE with a mean particle diameter of 353.97 nm and a PDI of 0.629. The antimicrobial effect of MA-OHE/ZnAC was evaluated against Staphylococcus aureus (S. aureus) and Cutibacterium acnes (C. acnes), which contribute to acne inflammation. The antibacterial activity of MA-OHE/ZnAC was 0.1 and 0.025 mg/mL to S. aureus and C. acnes, respectively, which were close to naturally derived antibiotics. Additionally, the cytotoxicity of MA-OHE, ZnAC, and MA-OHE/ZnAC was tested, and the results showed that they had no cytotoxic effects on cultured human keratinocytes in a range of 10-100 µg/mL. Thus, MA-OHE/ZnAC is suggested to be a promising antimicrobial agent for treating acne-inducing microbes, while MA-OHE/ZnAC PE is a potentially advantageous dermal delivery system.

Antibacterial activity and underlying mechanism of Meconopsis quintuplinervia Regel extract against the acne-causing bacteria Propionibacterium acnes and Staphylococcus aureus.

The aim of this study was to evaluate the antibacterial activity and underlying mechanism of ethanol extracts of Meconopsis quintuplinervia Regel (EMQ) against the acne-causing bacteria Propionibacterium acnes and Staphylococcus aureus. The study results indicated that EMQ was an effective antibacterial agent against P. acnes and S. aureus, with a DIZ of 14.5 and 13.2mm, MIC of 12.5 and 12.5mg/mL and MBC of 100 and 50mg/mL, respectively. EMQ induced morphological changes to bacterial cells, as determined by electron microscopy. Leakage of alkaline phosphatase and nucleic acids confirmed that EMQ compromised the membrane integrity of bacterial cells. Furthermore, protein analysis revealed that EMQ hindered total protein expression and lowered adenosine triphosphatase activity, while crystal violet staining revealed suppressed biofilm production. Bacterial adhesion analysis demonstrated that EMQ lowered the adhesive capacity of bacterial cells. The main chemical components of EMQ, identified by LC-MS, seem to have important roles in the antimicrobial effects against P. acnes and S. aureus, suggesting EMQ is a promising therapeutic for acne treatment.

Change in Cutibacterium acnes phylotype abundance and improvement of clinical parameters using a new dermocosmetic product containing Myrtus communis and Celastrol enriched plant cell culture extracts in patients with acne vulgaris.

BACKGROUND: Acne is a multifactorial chronic inflammatory disease of the pilosebaceous unit, where Cutibacterium acnes plays a main role. Recent papers demonstrated that specific C. acnes phylotypes were correlated with the severity of inflammatory acne and reported a specific loss of C. acnes phylotype diversity in this context. OBJECTIVES: The aim of this exploratory study was to evaluate the efficacy of a new dermocosmetic product containing Myrtus communis and Celastrol-enriched plant cell culture extracts on C. acnes phylotype abundance and clinical parameters in subjects with mild to moderate acne vulgaris. METHODS: Cutibacterium acnes phylotype diversity was evaluated by single-locus sequence typing sequencing on the nonlesional areas of the forehead, that is, areas excluding inflammatory lesions (papules and pustules) on day 1 (D1) and after 56 days (D57) of twice daily application of the dermocosmetic product on the whole face. Clinical efficacy on acne was also assessed by acne lesion counting and Global Evaluation Acne (GEA) score on D1 and D57. RESULTS: Our study confirmed the link between the presence of some C. acnes phylotypes and acne severity. The dermocosmetic cream was linked to a positive impact on C. acnes phylotypes: a significant decrease in pro-pathogen phylotype IC and increase in nonpathogen phylotype IB were observed in the nonlesional areas of acne on D57 compared to D1. In parallel, the clinical results showed a significant decrease in inflammatory and comedonal acne lesions and a significant improvement in the acne severity according to the GEA score. CONCLUSIONS: This study showed that the application of a new dermocosmetic product containing M. communis and Celastrol-enriched plant cell culture extracts was linked to a change in the C. acnes phylotype abundance and an improvement in acne severity.

Myrtus communis and Celastrol enriched plant cell culture extracts control together the pivotal role of Cutibacterium acnes and inflammatory pathways in acne.

INTRODUCTION: Acne is a multifactorial inflammatory disease of the pilosebaceous unit in which Cutibacterium acnes is one of the main triggers. A strong predominance of C. acnes phylotype IA1 is present in acne skin with higher biofilm organization and virulence, promoting local immuno-inflammation, especially the Th17 pathway. OBJECTIVES: We evaluated the single and combined pharmacological properties of the plant extracts, Myrtus communis (Myrtacine®) and Celastrol enriched plant cell culture (CEE) extracts on the C. acnes/Th17 pathway. METHODS: The effect of Myrtacine® on the virulence of C. acnes phylotype IA1 was quantified according to the expression of several related genes. The activity of Myrtacine® and CEE on the inflammatory cascade was assessed using monocytes-derived dendritic cells (Mo-DC) stimulated with membranes or biofilms of the C. acnes phylotype IA1. Finally, the effect of CEE on the Th17 pathway was studied using C. acnes stimulated sebocyte 2D cultures and 3D skin tissue models containing preactivated Th17 cells. RESULTS: Myrtacine® had an anti-virulence effect, evident as a significant and strong inhibition of the expression of several virulence factor genes by 60%-95% compared to untreated controls. Myrtacine® and CEE significantly inhibited proinflammatory cytokine (IL-6, IL-8, IL-12p40 and TNF-α) production by Mo-DC in response to C. acnes phylotype IA1. Interestingly, these two ingredients resulted in synergistic inhibition of most cytokines when used in combination. Finally, we demonstrated an inhibitory effect of CEE, in solution or formulated at 0.3%, specifically on IL-17 release by Th17 lymphocytes in a C. acnes-stimulated sebocyte 2D cultures and by Th17-lymphocytes integrated in a 3D skin models. CONCLUSIONS: 2D and 3D models were developed to represent relevant and specific pathways involved in acne. Myrtacine® and CEE were shown to alter one or more of these pathways, indicating their potential beneficial effects on this disease.

Antimicrobial Activity of Smilax china L. Root Extracts against the Acne-Causing Bacterium, Cutibacterium acnes, and Its Active Compounds.

The root of Smilax china L. is used in traditional Korean medicine. We found that the Smilax china L. root extract has strong antimicrobial activity against two Cutibacterium acnes strains (KCTC 3314 and KCTC 3320). The aim of this study was to identify the beneficial properties of Smilax china L. extracts for their potential use as active ingredients in cosmetics for the treatment of human skin acne. The high-performance liquid chromatography (HPLC) and liquid chromatography-hybrid quadrupole time-of-flight mass spectrometry (LC/QTOF/MS) methods were used to obtain the profile of secondary metabolites from the ethyl acetate-soluble fraction of the crude extract. Agar diffusion and resazurin-based broth microdilution assays were used to evaluate antimicrobial activity and minimum inhibitory concentrations (MIC), respectively. Among the 24 metabolites, quercetin, resveratrol, and oxyresveratrol were the most potent compounds against Cutibacterium acnes. Minimum inhibitory concentrations of quercetin, resveratrol, and oxyresveratrol were 31.25, 125, and 250 µg/mL, respectively.

Effect of combining Zingiber officinale and Juglans regia extracts on Propionibacterium acnes, Staphylococcus aureus and Staphylococcus epidermidis: antibiofilm action and low toxicity.

Objective was evaluated the therapeutic effect of Juglans regia (J) and Zingiber officinale (Z) extracts, alone or associated (Z75% + J25%, Z50% + J50% and Z25% + J75%) applied on planktonic cultures and biofilms of Propionibacterium acnes, Staphylococcus epidermidis and Staphylococcus aureus, as well as analyzing the cytotoxic effects of plant extracts on mouse macrophages (Raw 264-7). Broth microdilution assay was performed (M7-A6 - CLSI). Anti-biofilm activities and cytotoxicity on Raw 264-7 were studied using MTT assay and scanning electron microscopy. ANOVA with post-hoc Tukey HSD applied for parametric data and Kruskal-Wallis with Conover-Iman test, for non-parametric (p<0.05). On P. acnes biofilm, Z50% + J50% reduced 46.9% in 5 min and Z25% + J75% reduced 74.1% in 24hs. On S. aureus, Z75% + J25% reduced 23.1% in 5 min Z25% +J75% reduced 79.4% in 24hs. On S. epidermidis, Z75% + J25% reduced 74.6% in 5 min and 82.05% in 24 h. The treatments on macrophages for 24 h promoted a maximum reduction by 14,5% for groups of extracts associations. On multispecies biofilm, Z75%+J25% reduced 84.3% in 24 h. In conclusion association of glycolic extracts provided therapeutic effect, demonstrated antimicrobial activity and low cytotoxicity.

Ameliorative Effect of Bouea macrophylla Griffth Seed Extract Against Bacteria-Induced Acne Inflammation: in vitro study.

Currently, bioactive compounds derived from nature have been thought to be promising anti-acne substances owing to the variety of potential biological effects. This study aimed to evaluate the ameliorative effect of Bouea macrophylla Griffth seed extract against bacteria-induced acne inflammation for the first time in terms of antibacterial effects against acne-inducing bacteria, anti-inflammatory, and antioxidant properties. Initially, extracting procedures were optimized and five different extracts were obtained. Considering their antibacterial activities against Cutibacterium acnes, Staphylococcus aureus, and Staphylococcus epidermidis, ethanolic and ethyl acetate fractions exerted a notable effect which were highly superior above those of polyphenol standards. Additionally, these two extracts presented outstanding antioxidant capacities in terms of DPPH and ABTS radicals scavenging effects, reducing power, and inhibitory effect on lipid peroxidation which also play a role in the exacerbation of acne inflammation. Besides, inhibition on lipid peroxidation and reducing power of ethanolic fraction were significantly (p<0.05) better than those of ethyl acetate fraction which was corresponding to their phenolic and ellagic acid contents. However, flavonoids found in ethyl acetate fraction might play an important role in its potentials. After that, the anti-inflammatory effects of the extracts were elucidated by means of inhibition on nitric oxide production from LPS-induced RAW 264.7 cell lines at which the effects of both extracts were dosedependency. Taken together, our findings have apparently proven that B. macrophylla seed extracts exerted a variety of potential properties including antioxidation, anti-acne-inducing bacteria, and anti-inflammatory effects which could serve as a promising anti-acne agent for cosmeceutical applications.

Action of Mangifera indica Leaf Extract on Acne-Prone Skin through Sebum Harmonization and Targeting C. acnes.

(1) Background: Preclinical studies report that the ethanolic fraction from Mangifera indica leaves is a potential anti-acne agent. Nevertheless, the biological activity of Mangifera indica leaves has scarcely been investigated, and additional data are needed, especially in a clinical setting, for establishing the actual effectiveness of Mangifera indica extract as an active component of anti-acne therapy. (2) Methods: The evaluation of the biological activity of Mangifera indica extract was carried out through different experimental phases, which comprised in silico, in vitro, ex vivo and clinical evaluations. (3) Results: In silico and in vitro studies allowed us to identify the phytomarkers carrying the activity of seboregulation and acne management. Results showed that Mangifera indica extract reduced lipid production by 40% in sebocytes, and an improvement of the sebum quality was reported after the treatment in analyses performed on sebaceous glands from skin explants. The evaluation of the sebum quantity and quality using triglyceride/free fatty acid analysis conducted on Caucasian volunteers evidenced a strong improvement and a reduction of porphyrins expression. The C. acnes lipase activity from a severe acne phylotype was evaluated in the presence of Mangifera indica, and a reduction by 29% was reported. In addition, the analysis of the skin microbiota documented that Mangifera indica protected the microbiota equilibrium while the placebo induced dysbiosis. (4) Conclusions: Our results showed that Mangifera indica is microbiota friendly and efficient against lipase activity of C. acnes and supports a role for Mangifera indica in the therapeutic strategy for prevention and treatment of acne.

Kaempferia parviflora Rhizome Extract as Potential Anti-Acne Ingredient.

Kaempferia parviflora (Black ginger) is used widely in medical fields as an anti-microorganism and anti-inflammation. In this study, the aim was to evaluate the in vitro and in vivo anti-acne efficacy of black ginger extract. The results indicate that the methanol and ethanol extracts showed the highest total phenolic contents, without a significant difference, whereas the n-hexane extract showed the highest total flavonoid content. Nine flavones were detected using UPLC-QTOF-MS, and the ethyl acetate extract showed the highest amount of 5,7-dimethoxyflavone (DMF) according to HPLC. Antibacterial activity against Staphylococcus aureus, S. epidermidis, and Cutibacterium acnes was observed. All the extracts showed antimicrobial activity against C. acnes, revealing MICs in the range of 0.015 to 0.030 mg/mL, whereas the ethyl acetate extract inhibited the growth of S. epidermidis with a MIC of 3.84 mg/mL. In addition, the ethyl acetate extract showed the highest activity regarding nitric oxide inhibition (IC50 = 12.59 ± 0.35 µg/mL). The ethyl acetate extract was shown to be safe regarding cell viability at 0.1 mg/mL. The anti-acne efficacy was evaluated on volunteers. The volunteers were treated in two groups: one administered a 0.02% ethyl acetate extract gel-cream (n = 9) and one administered a placebo (n = 9) for 6 weeks. The group treated with the gel-cream containing the extract showed 36.52 and 52.20% decreases in acne severity index (ASI) after 4 and 6 weeks, respectively, and 18.19 and 18.54% decreases in erythema, respectively. The results suggest that K. parviflora could be a potent active ingredient in anti-inflammatory and anti-acne products.

Development and evaluation of herbal formulation AKIGTU01 and AKIGCL03 against acne producing microbes.

Acne vulgaris is a common global skin disease affecting teenagers and adults and exerting serious psychological impacts which includes everlasting scarring, reduced self-image, depression and anxiety. One of the suspected causative agent of acne is Propionibacterium acnes; a Gram positive anaerobic organism which lives in skin hair follicle and openings. Treatments currently available for acne include use of oral antibiotics, hormones, isotretinoin and also physical treatments like lesion removal and photo-therapy. All these are associated with risks and none is completely satisfactory.Therefore, natural alternatives are gaining greater research support but lacks sufficient studies. In our study we have isolated Propionibacterium acnes from infected individuals and tested the effect of certain chemicals and herbs/ vegetable extracts against it. There anti-acne property was studied and compared with commercially used antibiotics including Clinagel (Clindamycin phosphate), Vibramycin (Doxycycline), Erythromycin, Novidat (Ciprofloxacin) and Amoxil (Amoxicillin). Results indicate that some of the selected herbs and chemicals showed good activity against Propionibacterium acnes synergistic to the antibiotics when used alone or in combination. Findings of this research can play an important role in natural product based drug discovery for the treatment of Acne vulgaris.

Yin and Yang of skin microbiota in "swimmer acne".

Cutibacterium acnes (C. acnes) is an organism implicated in the pathogenesis of acne. Despite regular immersion in antimicrobial chlorine, adolescent swimmers suffer from acne and tend to be resistant to standard therapies. Given the presence of Pseudomonas within swimming facilities, we hypothesized that "swimmer acne" is potentially driven by a different microbial mechanism. In this study, we aimed to examine the microbial dynamics of C. acnes and Pseudomonadaceae, a family of gram-negative bacteria (includes Pseudomonas aeruginosa), in swimmers and its potential contribution to the pathogenesis of acne in this population. Using fluorescence photography that measures the Coproporphyrin III (CPIII), we quantitated an absolute abundance of C. acnes present on the face of each participant pre- and post-swimming. In addition, 16S rRNA gene sequencing was utilized to assess relative abundance of the skin microbiota on each participant pre- and post-swimming. 16 swimmers (8 girls and 8 boys) completed the study. Seven had acne on the face. The CPIII fluorescence levels decreased for all swimmers after 1 h of swimming (p-value <0.001). In contrast, the relative abundance of C. acnes remained unchanged, while that of Pseudomonadaceae increased after swimming (p-value =0.027). Comparing the relative abundances of Pseudomonadaceae before swimming, there was a significant increase in variance from the mean in acne group as compared to no acne group (p-value <0.001). Taken together, we conclude that the skin dysbiosis resulting from repeated decolonization and colonization of C. acnes and Pseudomonadaceae, respectively, can potentially be associated with the pathogenesis of acne in swimmers.

Chemical characterization and bioactive potential of Thymus×citriodorus (Pers.) Schreb. preparations for anti-acne applications: Antimicrobial, anti-biofilm, anti-inflammatory and safety profiles.

ETHNOPHARMACOLOGICAL RELEVANCE: Thymus × citriodorus (Pers.) Schreb. is an interspecific hybrid between Thymus pulegioides and Thymus vulgaris, known for its pharmacological activities as diaphoretic, deodorant, antiseptic and disinfectant, the last mostly related with its antimicrobial activity. The folk use of other extracts, as hydrolates, have also been disseminated, as regulators of oily skin with anti-acne effect. AIM OF THE STUDY: We aimed to evaluate the anti-acne potential of two Thymus x citriodorus (TC) preparations, the essential oil (EO) and the hydrolate, to be used as active ingredients for skin applications. Specifically, we intend to validate their anti-acne potential by describing their activity on acne related bacteria, bacterial virulence, anti-oxidant and anti-inflammatory potential, and biocompatibility on inflammatory cells. Additionally, we aimed to report their ecotoxicity under the Globally Harmonized System of Classification and Labelling of Chemicals (GHS), thus focusing not only on the consumer, but also on environmental safety assessment. MATERIALS AND METHODS: Minimum inhibitory concentration (MIC) against C. acnes, S. aureus and S. epidermidis was evaluated. Minimum lethal concentration (MLC) was also determined. The effect on C. acnes biofilm formation and disruption was evaluated with crystal violet staining. Anti-inflammatory activity was investigated on LPS-stimulated mouse macrophages (RAW 264.7), by studying nitric oxide (NO) production (Griess reagent) and cellular biocompatibility through MTT assay. In-vitro NO and 2,2-Diphenyl-1-picrylhydrazyl (DPPH) scavenging potential were also evaluated. The ecotoxicity was evaluated using Daphnia magna acute toxicity assays. RESULTS: EO presented direct antimicrobial activity, with visual MICs ranging from 0.06% for S. epidermidis and C. acnes to 0.125% for S. aureus. MLCs were higher than the obtained MICs. Hydrolate revealed visual MIC only for C. acnes. TC essential oil was effective in preventing biofilm formation and disrupting preformed biofilms even at sub-inhibitory concentrations. Hydrolate showed a more modest anti-biofilm effect. Regarding anti-inflammatory activity, TC hydrolate has a higher cellular biocompatibility. Still, both plant preparations were able to inhibit at least 50% of NO production at non-cytotoxic concentrations. Both EO and hydrolate have poor anti-oxidant activities. Regarding the ecotoxicity, TC essential oil was classified under acute 3 category, while the hydrolate has proved to be nontoxic, in accordance to the GHS. CONCLUSIONS: These results support the anti-acne value of different TC preparations for different applications. TC hydrolate by presenting higher biocompatibility, anti-inflammatory potential and the ability to modulate C. acnes virulence, can be advantageous in a product for everyday application. On the other hand, EO by presenting a marked antimicrobial, anti-biofilm and anti-inflammatory activities, still with some cytotoxicity, may be better suited for application in acute flare-ups, for short treatment periods.

Study of biosurfactant extract from corn steep water as a potential ingredient in antiacne formulations.

BACKGROUND: This is a novel work that includes the use of a biosurfactant extract obtained from corn milling industry (named BS-CSW), with antimicrobial activity, as ingredient in formulations to treat acne vulgaris. METHODOLOGY: With this purpose, it was established an incomplete experimental design with 3 independent variables, based on the concentration of non-nano zinc oxide (ZnO) (0-2%), BS-CSW (0-5%) and salicylic acid (0-2%). RESULTS: This design allowed to obtain a theoretical model that calculates the inhibitory effect on Cutibacterium acnes (also named Propionibacterium acnes) for any formulation carried with the ingredients appointed before. It was observed a clear synergetic effect on the inhibition of C. acnes between ZnO and BS-CSW, in absence of salicylic acid. This fact allowed to reduce the concentration of ZnO, giving more ecofriendly and biocompatible formulations. CONCLUSIONS: It was observed that the biosurfactant extract, in formulations with intermediate concentration of ZnO (1%), possess an inhibitory effect on C. acnes considerably higher than ZnO alone and similar to ZnO (1%) with salicylic acid (1%). This fact demonstrates the enormous potential of this bioactive extract in antiacne formulations.

The use of light in the treatment of acne vulgaris-a review.

Topical and oral antibiotic therapy is also a popular method of treatment. The effectiveness of this method is limited by the increasing resistance of bacteria to antibiotics. Over the decades since the introduction of antibiotics to treat acne, the resistance levels of bacteria have changed. This defense mechanism is developed evolutionarily. Modifications of antibiotic receptor sites, alteration of drug influx/efflux, or enzymatic degradation are common mechanisms used by bacteria to initiate and strengthen internal antibiotic resistance. The basic chromophores used in light therapy are hemoglobin, melanin, water bound to proteins, and porphyrins. Hemoglobin absorbs light mainly at 580 nm, while melanin absorbs the entire visible spectral range (400-750 nm). Porphyrins are aromatic compounds, classified as photosensitizing substances, intensively absorbing blue light, and to a lesser extent in long visible bands, such as orange and red light. Using IPL makes it possible to cover the maximum light absorption of porphyrins and hemoglobin, therefore it can be an effective tool in the treatment of inflammatory lesions in acne vulgaris. In view of the effectiveness of light therapy and its effect even on antibiotic-resistant bacteria, it is worth considering the possibility of using light therapy instead of antibiotic therapy. Due to the increasing resistance of bacteria to antimicrobials, they should be used with caution and as a last resort. The high-energy light treatment act only locally (unlike with antibiotics taken orally) and on a chromophore, such as melanin, hemoglobin, or porphyrins.

Therapeutic Efficacy of Sesquiterpene Farnesol in Treatment of Cutibacterium acnes-Induced Dermal Disorders.

Acne vulgaris is a highly prevalent skin disorder requiring treatment and management by dermatologists. Antibiotics such as clindamycin are commonly used to treat acne vulgaris. However, from both medical and public health perspectives, the development of alternative remedies has become essential due to the increase in antibiotic resistance. Topical therapy is useful as a single or combined treatment for mild and moderate acne and is often employed as maintenance therapy. Thus, the current study investigated the anti-inflammatory, antibacterial, and restorative effects of sesquiterpene farnesol on acne vulgaris induced by Cutibacterium acnes (C. acnes) in vitro and in a rat model. The minimum inhibitory concentration (MIC) of farnesol against C. acnes was 0.14 mM, and the IC50 of 24 h exposure to farnesol in HaCaT keratinocytes was approximately 1.4 mM. Moreover, 0.8 mM farnesol exhibited the strongest effects in terms of the alleviation of inflammatory responses and abscesses and necrotic tissue repair in C.acnes-induced acne lesions; 0.4 mM farnesol and clindamycin gel also exerted similar actions after a two-time treatment. By contrast, nearly doubling the tissue repair scores, 0.4 mM farnesol displayed great anti-inflammatory and the strongest reparative actions after a four-time treatment, followed by 0.8 mM farnesol and a commercial gel. Approximately 2-10-fold decreases in interleukin (IL)-1ß, IL-6, and tumor necrosis factor (TNF)-α, found by Western blot analysis, were predominantly consistent with the histopathological findings and tissue repair scores. The basal hydroxypropyl methylcellulose (HPMC) gel did not exert anti-inflammatory or reparative effects on rat acne lesions. Our results suggest that the topical application of a gel containing farnesol is a promising alternative remedy for acne vulgaris.

Efficacy of combinational therapy using blue light and benzoyl peroxide in reducing Cutibacterium acnes bioburden at the deltopectoral interval: a randomized controlled trial.

BACKGROUND: The purpose of this study was to compare the efficacy of blue light therapy (BLT) and 5% topical benzoyl peroxide (BPO) gel in combination with standard chlorhexidine (CHX) preparation in eradicating Cutibacterium acnes at the deltopectoral interval measured by positive, quantitative culture findings. METHODS: Adult male volunteers were randomized to 1 of 3 treatment groups: BPO, BLT, and BPO followed by BLT. Contralateral shoulders served as matched controls. Volunteers randomized to BPO applied the gel for a total of 5 treatments. In the BLT group, a single 23-minute treatment was administered at an estimated irradiance of 40 mW/cm2 (radiant exposure, 55.2 J/cm2). In the BPO-BLT group, volunteers received both treatments as described earlier. After treatment with either BPO, BLT, or both, a single swab culture was taken from the treatment shoulder. Next, control and treatment shoulders were prepared with CHX, and cultures were taken from each shoulder. Cultures were sent for anaerobic quantitative growth analysis with both polymerase chain reaction and Sanger sequencing confirmation of presumptive C acnes colonies. RESULTS: This study enrolled 60 male volunteers, 20 per group, with no loss to follow-up. After treatment but prior to CHX administration, all culture samples in the BPO group and BLT group grew C acnes. Prior to CHX, 16 samples (80%) in the BPO-BLT group grew C acnes. On quantitative analysis, the BPO group and BPO-BLT group had significantly less growth of C acnes compared with the BLT group after treatment but prior to CHX (P < .05 for each). Following CHX administration, the BPO and BPO-BLT groups had significantly fewer positive culture findings (odds ratios of 0.03 and 0.29, respectively) and less quantity of growth compared with their control arms (P < .05). This was not seen in the BLT group. For quantitative between-group analysis, no significant synergistic effects were seen with BPO-BLT compared with BPO alone (P = .688). There was no difference in side effects between groups. CONCLUSION: The combination of topical BPO and CHX was effective at eliminating C acnes in most cases. BLT alone did not demonstrate effective antimicrobial properties against C acnes at the radiant exposure administered in this study. Combining BPO and BLT did not lead to significant synergistic antimicrobial effects. Both BPO and BLT are safe with few, transient side effects reported. More work is needed to determine whether BLT at higher radiant exposures or serial treatment results in bactericidal effects against C acnes in vivo.