Double-blind, randomized, placebo-controlled study of a lotion containing triethyl citrate and ethyl linoleate in the treatment of acne vulgaris

Effects of Silybum marianum L. Seed Extracts on Multi Drug Resistant (MDR) Bacteria

Wound infections became a great challenge, especially after the emergence of bacterial resistance to commonly used antibiotics. Medicinal plants can be the source of alternative antibacterial agents effective against multi drug resistant (MDR) bacteria. This research aimed to evaluate the effectiveness of different Silybum marianum seed extracts in fighting MDR bacteria that infect wounds. First, thirty purified bacterial cultures obtained from superficial, infected wounds were subjected to antibiotic sensitivity tests. The selected MDR isolates were then used to test the antimicrobial effects of different S. marianum seed extracts. The most potent extract was evaluated for its impact on the ultrastructure of the cells of sensitive bacterial isolates using transmission electron microscopy (TEM). The bioactive ingredients of this extract were analyzed by means of gas chromatography-mass spectroscopy (GC-MS). Then, in-silico absorption, distribution, metabolism, excretion, and toxicity (ADMET) properties were predicted for the main components. The results indicated that four out of 30 bacterial isolates were considered MDR bacteria. Primary morphological features of colonies, secondary (automatic) identification using the Biomerieux Vitek 2 System, and 16S rRNA sequencing of the four isolates confirmed that they represent Staphylococcus aureus, Stenotrophomonas maltophilia, Klebsiella pneumoniae, and Escherichia coli. Among different extracts of S. marianum seeds, ethanol extract showed the strongest inhibitory effect on both Gram-positive and Gram-negative bacteria, with minimum inhibitory concentration (MIC) values between 9.375 and 1.172 mg/mL. However, at concentrations four times higher, this extract was unable to kill bacterial cells, indicating that it had a bacteriostatic effect on the tested MDR strains. TEM revealed denaturation and distorted cell ultrastructure in S. aureus and S. maltophilia after exposure to ethanol extract. In addition, GC-MS analysis of the ethanol extract identified nine compounds known to have important biological activities, and ADMET analysis showed good drug-likeness for two of these compounds. Consequently, S. marianum seeds could be a good source of alternative bacteriostatic agents effective against MDR bacterial strains that cause wound infections.

Bakuchiol and ethyl (linoleate/oleate) synergistically modulate endocannabinoid tone in keratinocytes and repress inflammatory pathway mRNAs

The endocannabinoid (eCB) system plays an active role in epidermal homeostasis. Phytocannabinoids such as cannabidiol modulate this system but also act through eCB-independent mechanisms. This study evaluated the effects of cannabidiol, bakuchiol (BAK), and ethyl (linoleate/oleate) (ELN) in keratinocytes and reconstituted human epidermis. Molecular docking simulations showed that each compound binds the active site of the eCB carrier FABP5. However, BAK and ethyl linoleate bound this site with the highest affinity when combined 1:1 (w/w), and in vitro assays showed that BAK + ELN most effectively inhibited FABP5 and fatty acid amide hydrolase. In TNF-stimulated keratinocytes, BAK + ELN reversed TNF-induced expression shifts and uniquely downregulated type I IFN genes and PTGS2 (COX2). BAK + ELN also repressed expression of genes linked to keratinocyte differentiation but upregulated those associated with proliferation. Finally, BAK + ELN inhibited cortisol secretion in reconstituted human epidermis skin (not observed with cannabidiol). These results support a model in which BAK and ELN synergistically interact to inhibit eCB degradation, favoring eCB mobilization and inhibition of downstream inflammatory mediators (e.g., TNF, COX-2, type I IFN). A topical combination of these ingredients may thus enhance cutaneous eCB tone or potentiate other modulators, suggesting novel ways to modulate the eCB system for innovative skincare product development.

GC-MS Analysis and Biomedical Therapy of Oil from n-Hexane Fraction of Scutellaria edelbergii Rech. f.: In Vitro, In Vivo, and In Silico Approach

The current study aimed to explore the crude oils obtained from the n-hexane fraction of Scutellaria edelbergii and further analyzed, for the first time, for their chemical composition, in vitro antibacterial, antifungal, antioxidant, antidiabetic, and in vivo anti-inflammatory, and analgesic activities. For the phytochemical composition, the oils proceeded to gas chromatography-mass spectrometry (GC-MS) analysis and from the resultant chromatogram, 42 bioactive constituents were identified. Among them, the major components were linoleic acid ethyl ester (19.67%) followed by ethyl oleate (18.45%), linolenic acid methyl ester (11.67%), and palmitic acid ethyl ester (11.01%). Tetrazolium 96-well plate MTT assay and agar-well diffusion methods were used to evaluate the isolated oil for its minimum inhibitory concentrations (MIC), minimum bactericidal concentration (MBC), half-maximal inhibitory concentrations (IC₅₀), and zone of inhibitions that could determine the potential antimicrobial efficacy's. Substantial antibacterial activities were observed against the clinical isolates comprising of three Gram-negative bacteria, viz., Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa, and one Gram-positive bacterial strain, Enterococcus faecalis. The oils were also effective against Candida albicans and Fusarium oxysporum when evaluated for their antifungal potential. Moreover, significant antioxidant potential with IC₅₀ values of 136.4 and 161.5 µg/mL for extracted oil was evaluated through DPPH (1,1-Diphenyl-2-picryl-hydrazyl) and ABTS assays compared with standard ascorbic acid where the IC50 values were 44.49 and 67.78 µg/mL, respectively, against the tested free radicals. The oils was also potent, inhibiting the α-glucosidase (IC50 5.45 ± 0.42 µg/mL) enzyme compared to the standard. Anti-glucosidase potential was visualized through molecular docking simulations where ten compounds of the oil were found to be the leading inhibitors of the selected enzyme based on interactions, binding energy, and binding affinity. The oil was found to be an effective anti-inflammatory (61%) agent compared with diclofenac sodium (70.92%) via the carrageenan-induced assay. An appreciable (48.28%) analgesic activity in correlation with the standard aspirin was observed through the acetic acid-induced writhing bioassay. The oil from the n-hexane fraction of S. edelbergii contained valuable bioactive constituents that can act as in vitro biological and in vivo pharmacological agents. However, further studies are needed to uncover individual responsible compounds of the observed biological potentials which would be helpful in devising novel drugs.

Purification of Ethyl Linoleate from Foxtail Millet (Setaria italica) Bran Oil via Urea Complexation and Molecular Distillation

Foxtail millet (Setaria italica) bran oil is rich in linoleic acid, which accounts for more than 60% of its lipids. Ethyl linoleate (ELA) is a commercially valuable compound with many positive health effects. Here, we optimized two ELA processing steps, urea complexation (UC) and molecular distillation (MD), using single-factor and response surface analyses. We aimed to obtain a highly concentrated ELA at levels that are permitted by current regulations. We identified the optimal conditions as follows: 95% ethanol-to-urea ratio = 15:1 (w/w), urea-to-fatty acid ratio = 2.5:1 (w/w), crystallization time = 15 h, and crystallization temperature = -6 °C. Under these optimal UC conditions, ELA concentration reached 45.06%. The optimal MD purification conditions were established as follows: distillation temperature = 145 °C and vacuum pressure = 1.0-5.0 × 10^-2 mbar. Under these conditions, ELA purity increased to 60.45%. Together, UC and MD were effective in improving the total concentration of ELA in the final product. This work shows the best conditions for separating and purifying ELA from foxtail millet bran oil by UC and MD.

Acne - therapeutic challenges to the cooperation between a dermatologist and a cosmetologist

Acne vulgaris is one of the most common skin diseases in adolescence, causing a significant negative impact on the quality of life of young people who - in a large percentage of cases - do not accept their appearance. The complex pathogenesis of this disease requires appropriate preventive and curative treatment from both a dermatologist and a cosmetologist. The aim of the study was to discuss the methods currently used by dermatologists in local therapy for mild and intermediate forms of acne vulgaris, and to provide an overview of possible preventive and caring activities in the cosmetologist's office. Possible directions of cooperation between the dermatologist and the cosmetologist in the prevention of acne relapse and treatment of possible acne complications were also discussed.

Comparative Efficacy of Pharmacological and Nonpharmacological Interventions for Acne Vulgaris: A Network Meta-Analysis

Acne has several effects on physical symptoms, but the main impacts are on the quality of life, which can be improved by treatment. There are several acne treatments but less evidence comparing their relative efficacy. Thus, we assessed the comparative efficacy of pharmacological and nonpharmacological interventions for acne. We searched PubMed, Embase, and the Cochrane Central Register of Controlled Trials from inception to April 2019, to include randomized controlled trials for acne that compared topical antibiotics (TA), benzoyl peroxide (BPO), topical retinoids (TR), oral antibiotics (OA), lasers, light devices including LED device (LED), photodynamic therapy (PDT), and intense pulsed light, chemical peels (CP), miscellaneous therapies or complementary and alternative medicine (MTCAM), or their combinations. We performed Bayesian network meta-analysis with random effects for all treatments compared with placebo and each other. Mean differences (MDs) of lesions count and risk ratios of adverse events with their 95% credible intervals (CrIs) were calculated, and all interventions were ranked by the Surface Under the Cumulative Ranking (SUCRA) values. Additional frequentist additive network meta-analysis was performed to detect the robustness of results and potential interaction effects. Sensitivity analyses were carried out with different priors, and metaregression was to adjust for nine potential effect modifiers. In the result, seventy-three randomized controlled trials (27,745 patients with mild to moderate acne), comparing 30 grouped intervention categories, were included with low to moderate risk of bias. For adverse effects, OA had more risk in combination treatment with others. For noninflammatory lesions reduction, seventeen interventions had significant differences comparing with placebo and three interventions (TR+BPO: MD = −21.89, 95%CrI [−28.97, −14.76]; TR+BPO+MTCAM: −22.48 [−34.13, −10.70]; TA+BPO+CP: −20.63 [−33.97, −7.13]) were superior to others with 94, 94, and 91% SUCRA values, respectively. For inflammatory lesions reduction, nineteen interventions were significantly better than placebo, and three interventions (TR+BPO: MD = −12.13, 95%CrI [−18.41, −5.80]; TR+BPO+MTCAM: −13.21 [−.39, −3.04]; LED: −11.30 [−18.34, −4.42]) were superior to others (SUCRA: 81, 81, and 77%, respectively). In summary of noninflammatory and inflammatory lesions results, TR+BPO and TA+BPO were the best options compared to others. The frequentist model showed similar results as above. In summary, current evidence supports the suggestion that TR+BPO and TA+BPO are the best options for mild to moderate acne. LED is another option for inflammatory lesions when drug resistance occurs. All the combinations involved with OA showed more risk of adverse events than others. However, the evidence of this study should be cautiously used due to the limitations.

Isosorbide Di-(Linoleate/Oleate) Stimulates Prodifferentiation Gene Expression to Restore the Epidermal Barrier and Improve Skin Hydration

The breakdown of the epidermal barrier and consequent loss of skin hydration is a feature of skin aging and eczematous dermatitis. Few treatments, however, resolve these underlying processes to provide full symptomatic relief. In this study, we evaluated isosorbide di-(linoleate/oleate) (IDL), which was generated by esterifying isosorbide with sunflower fatty acids. Topical effects of IDL in skin were compared with those of ethyl linoleate/oleate, which has previously been shown to improve skin barrier function. Both IDL and ethyl linoleate/oleate downregulated inflammatory gene expression, but IDL more effectively upregulated the expression of genes associated with keratinocyte differentiation (e.g., KRT1, GRHL2, SPRR4). Consistent with this, IDL increased the abundance of epidermal barrier proteins (FLG and involucrin) and prevented cytokine-mediated stratum corneum degradation. IDL also downregulated the expression of unhealthy skin signature genes linked to the loss of epidermal homeostasis and uniquely repressed an IFN-inducible coexpression module activated in multiple skin diseases, including psoriasis. In a double-blind, placebo-controlled trial enrolling females with dry skin, 2% IDL lotion applied over 2 weeks significantly improved skin hydration and decreased transepidermal water loss (NCT04253704). These results demonstrate mechanisms by which IDL improves skin hydration and epidermal barrier function, supporting IDL as an effective intervention for the treatment of xerotic pruritic skin.

Efficacy and tolerability of a lotion containing triethyl citrate, ethyl linoleate, and GT peptide-10 in the adjuvant treatment of hidradenitis suppurativa: Real-life data

Hidradenitis suppurativa (HS) is a chronic disorder of terminal follicular epithelium in the apocrine gland-bearing areas. The long term therapy is based mainly on topical and/or systemic antibiotic use that could result in antibiotic resistance. The aim of our study was to present the real-life experience based on the efficacy and tolerability of a novel lotion containing triethyl-citrate, ethyl-linoleate, and g-peptide-10 in the treatment of mild to moderate HS that has already shown effectiveness in acne treatment. This was an open-label study on 30 patients of both sexes affected by HS. Patients were divided into two groups: 15 with Hurley I and 15 with Hurley II-III. The subjects were treated with the topical lotion, three-times-daily for eight weeks, with control at 4 (T₁ ) and eight weeks (T₂ ). Any other concomitant treatment (both topical and/or systemic) was avoided during study period. Improvement was observed in both Sartorius score grading system and inflammatory and noninflammatory lesion counts. The novel lotion has proved to be effective and well-tolerated topical agent alone or in association with other topical and/or systemic tratments in HS, without side effects.

Ethyl linoleate inhibits α-MSH-induced melanogenesis through Akt/GSK3β/β-catenin signal pathway

Ethyl linoleate is an unsaturated fatty acid used in many cosmetics for its various attributes, such as antibacterial and anti-inflammatory properties and clinically proven to be an effective anti-acne agent. In this study, we investigated the effect of ethyl linoleate on the melanogenesis and the mechanism underlying its action on melanogenesis in B16F10 murine melanoma cells. Our results revealed that ethyl linoleate significantly inhibited melanin content and intracellular tyrosinase activity in α-MSH-induced B16F10 cells, but it did not directly inhibit activity of mushroom tyrosinase. Ethyl linoleate inhibited the expression of microphthalmia-associated transcription factor (MITF), tyrosinase, and tyrosinase related protein 1 (TRP1) in governing melanin pigment synthesis. We observed that ethyl linoleate inhibited phosphorylation of Akt and glycogen synthase kinase 3β (GSK3β) and reduced the level of β-catenin, suggesting that ethyl linoleate inhibits melanogenesis through Akt/GSK3β/β-catenin signal pathway. Therefore, we propose that ethyl linoleate may be useful as a safe whitening agent in cosmetic and a potential therapeutic agent for reducing skin hyperpigmentation in clinics.

Demonstration of biological activities of extracts from Isodon rugosus Wall. Ex Benth: Separation and identification of bioactive phytoconstituents by GC-MS analysis in the ethyl acetate extract

Background

Since long, natural sources have been explored for possible managements of various diseases. In this context, the study is designed to evaluate Isodon rugosus Wall. ex Benth for biological potentials including antibacterial, anthelmintic, insecticidal, anti-termites and anti-Pharaoh activities followed by GC-MS analysis of active fraction to identify various bioactive compounds.

Methods

I. rugosus was investigated against eight bacterial strains using well diffusion method and microdilution method with ceftriaxone as positive control. Similarly, the insecticidal activity was carried out against Tribolium castaneum, Rhyzopertha dominica, Monomorium pharaonis and Heterotermis indicola following contact toxicity method. Likewise, anthelmintic activity was performed against Ascaridia galli and Pherethima posthuma using albendazole as positive control, in which the paralysis and death times of the worms were observed. The GC-MS analysis of the most active solvent fraction was performed for identifications of various bioactive compounds.

Results

Among the tested samples of I. rugosus, flavonoids and ethyl acetate fraction exhibited high antibacterial activities. The crude saponins showed highest anthelmintic activity against Pherethima posthuma and Ascaridia galli with death times of 27.67 and 29.22 min respectively at concentrations of 40 mg/ml. In insecticidal activity, chloroform fraction and saponins exhibited notable results against R. dominica (60 and 70%) and T. castaneum (70 and 76%) at concentration of 200 mg/ml. In anti-termite assay, all the plant samples showed overwhelming results, i.e. all the 25 termites were killed on the 3rd day. Similarly, in anti-Pharaoh activity, the chloroform, ethyl acetate and saponins fractions were most potent, each exhibiting LD₅₀ of <0.1 mg/ml. In GC-MS analysis, total of 57 compounds were identified. Some of the bioactive compounds identified in GC-MS analysis are palmitic acid, hinokiol, α-amyrin, phytol, ethyl linolate, cyclohexanone, hinokione, methyl palmitate, ethyl palmitate and stigmasterol acetate.

Conclusions

Based on our current results, it can be concluded that I. rugosus possess strong antibacterial, insecticidal and anthelmintic potentials having crude saponins and ethyl acetate as the most active fractions. The GC-MS analysis and biological assays reveal that ethyl acetate fraction is a suitable target for the isolation of diverse array of bioactive compounds.

Two new fatty acids esters were detected in ginseng stems by the application of azoxystrobin and the increasing of antioxidant enzyme activity and ginsenosides content

Panax ginseng C.A. Meyer is a valuable herb in China that has also gained popularity in the West because of its pharmacological properties. The constituents isolated and characterized in ginseng stems include ginsenosides, fatty acids, amino acids, volatile oils, and polysaccharides. In this study, the effects of fungicide azoxystrobin applied on antioxidant enzyme activity and ginsenosides content in ginseng stems was studied by using Panax ginseng C. A. Mey. cv. (the cultivar of Ermaya) under natural environmental conditions. The azoxystrobin formulation (25% SC) was sprayed three times on ginseng plants at different doses (150ga.i./ha and 225ga.i./ha), respectively. Two new fatty acids esters (ethyl linoleate and methyl linolenate) were firstly detected in ginseng stems by the application of azoxystrobin as foliar spray. The results indicated that activities of enzymatic antioxidants, the content of ginsenosides and two new fatty acids esters in ginseng stems in azoxystrobin-treated plants were increased. Azoxystrobin treatments to ginseng plants at all growth stages suggest that the azoxystrobin-induced delay of senescence is due to an enhanced antioxidant enzyme activity protecting the plants from harmful active oxygen species (AOS). The activity of superoxide dismutase (SOD) in azoxystrobin-treated plants was about 1-3 times higher than that in untreated plants. And the effects was more significant (P=0.05) when azoxystrobin was applied at dose of 225ga.i./ha. This work suggests that azoxystrobin plays an important role in delaying of senescence by changing physiological and biochemical indicators and increasing ginsenosides content in ginseng stems.

The long-term effect of 1550 nm erbium:glass fractional laser in acne vulgaris

We evaluated the short-term and long-term effects of the 1550 nm erbium:glass (Er:glass) fractional laser in the treatment of facial acne vulgaris. Forty-five (9 male and 36 female) acne patients were treated 4 times at 4-week intervals with the following parameters: 169 spot density and 15-30 mJ/cm(2) fluence. There was no control group. The laser spots were adjustable (maximum overlap: 20%) according to the treatment area, and delivered in rows in order to cover all the face. Clinical photographs were taken. The IGA scores and lesion counts were performed for each treatment. Their current state was obtained by phone call follow-up to determine the long-term effect and photographs were offered by themselves or taken in hospital. After four treatments, all patients had an obvious reduction of lesion counts and IGA score and the peak lesion counts decreased to 67.7% after the initial four treatment sessions. For long-term effect, 8 patients lost follow-up, hence 37 patients were followed-up. 8 patients were 2-year follow up, 27 at the 1-year follow-up, and all patients at the half-year follow-up. The mean percent reduction was 72% at the half-year follow-up, 79 at the 1-year follow-up and 75% at the 2-year follow-up. Side effects and complications were limited to transient erythema and edema, and few patients suffered from transient acne flare-ups and sensitivity. All patients responded that their skin was less prone to oiliness. In conclusion, acne can be successfully treated by 1550 nm Er:glass fractional laser, with few side effects and prolonged acne clearing.

Chemical composition and biological activities of trans-Himalayan alga Spirogyra porticalis (Muell.) Cleve

The freshwater alga Spirogyra porticalis (Muell.) Cleve, a filamentous charophyte, collected from the Indian trans-Himalayan cold desert, was identified on the basis of morpho-anatomical characters. Extracts of this alga were made using solvents of varying polarity viz. n-hexane, acetonitrile, methanol and water. The antioxidant capacities and phenolic profile of the extracts were estimated. The methanol extract showing highest antioxidant capacity and rich phenolic attributes was further investigated and phytochemical profiling was conducted by gas chromatography-mass spectrometry (GC/MS) hyphenated technique. The cytotoxic activity of methanol extract was evaluated on human hepatocellular carcinoma HepG2 and colon carcinoma RKO cell lines. The anti-hypoxic effect of methanol extract of the alga was tested on in vivo animal system to confirm its potential to ameliorate oxidative stress. The antioxidant assays viz. ferric reducing antioxidant power (FRAP), 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS), 1,1-diphenyl-2-picrylhydrazyl (DPPH) and nitric oxide (NO) radical scavenging capacities, β-carotene-linoleic acid bleaching property and lipid peroxidation exhibited analogous results, wherein the algal extracts showed significantly high antioxidant potential. The extracts were also found to possess high content of total proanthocyanidin, flavonoid and polyphenol. GC/MS analysis revealed the presence of thirteen chemotypes in the methanol extract representing different phytochemical groups like fatty acid esters, sterols, unsaturated alcohols, alkynes etc. with substantial phyto-pharmaceutical importance. The methanol extract was observed to possess anticancer activity as revealed from studies on HepG2 and RKO cell lines. In the present study, S. porticalis methanol extract also provided protection from hypoxia-induced oxidative stress and accelerated the onset of adaptative changes in rats during exposure to hypobaric hypoxia. The bioactive phytochemicals present in this trans-Himalayan alga are of enormous interest and can be utilized sustainably for discovery of novel drugs against oxidative stress.

Salicylic acid peel incorporating triethyl citrate and ethyl linoleate in the treatment of moderate acne: a new therapeutic approach

BACKGROUND

Acne affects many adolescents. Conventional therapy often results in side effects and poor adherence, and the treatment does not consider the psychological effect of acne on patients, which is comparable with that of disabling diseases.

OBJECTIVES

To evaluate the efficacy and tolerability of a peel (30% salicylic acid, triethyl citrate and ethyl linoleate) combined with a home therapy with three topical agents (triethyl citrate, ethyl linoleate and salicylic acid 0.5% cream, lotion) in moderate acne of the face.

DESIGN

Prospective, observational, multicenter, open-label, postmarketing, phase IV study.

METHODS

Patients were assessed by comparing Global Acne Grading System (GAGS) score and total lesion count from 15 days before the first peel (T-15 ), after four salicylic peels (every 10 ± 2 days (T0 , T10 , T20 , T30 ), and 20 days after of the end of the study (T50 ). This treatment was associated to a home therapy.

RESULTS

Fifty-three patients completed the study. The average GAGS score fell 49% between T-15 and T50 (p < .001). No patient withdrew for adverse events.

CONCLUSIONS

This therapy was effective and well-tolerated in all cases. Chemo-exfoliation sessions ensured the continuous monitoring of clinical results and improved patient quality of life.

Acne vulgaris

Acne is a chronic inflammatory disease of the pilosebaceous unit resulting from androgen-induced increased sebum production, altered keratinisation, inflammation, and bacterial colonisation of hair follicles on the face, neck, chest, and back by Propionibacterium acnes. Although early colonisation with P acnes and family history might have important roles in the disease, exactly what triggers acne and how treatment affects the course of the disease remain unclear. Other factors such as diet have been implicated, but not proven. Facial scarring due to acne affects up to 20% of teenagers. Acne can persist into adulthood, with detrimental effects on self-esteem. There is no ideal treatment for acne, although a suitable regimen for reducing lesions can be found for most patients. Good quality evidence on comparative effectiveness of common topical and systemic acne therapies is scarce. Topical therapies including benzoyl peroxide, retinoids, and antibiotics when used in combination usually improve control of mild to moderate acne. Treatment with combined oral contraceptives can help women with acne. Patients with more severe inflammatory acne usually need oral antibiotics combined with topical benzoyl peroxide to decrease antibiotic-resistant organisms. Oral isotretinoin is the most effective therapy and is used early in severe disease, although its use is limited by teratogenicity and other side-effects. Availability, adverse effects, and cost, limit the use of photodynamic therapy. New research is needed into the therapeutic comparative effectiveness and safety of the many products available, and to better understand the natural history, subtypes, and triggers of acne.

New developments in our understanding of acne pathogenesis and treatment

Interest in sebaceous gland physiology and its diseases is rapidly increasing. We provide a summarized update of the current knowledge of the pathobiology of acne vulgaris and new treatment concepts that have emerged in the last 3 years (2005-2008). We have tried to answer questions arising from the exploration of sebaceous gland biology, hormonal factors, hyperkeratinization, role of bacteria, sebum, nutrition, cytokines and toll-like receptors (TLRs). Sebaceous glands play an important role as active participants in the innate immunity of the skin. They produce neuropeptides, excrete antimicrobial peptides and exhibit characteristics of stem cells. Androgens affect sebocytes and infundibular keratinocytes in a complex manner influencing cellular differentiation, proliferation, lipogenesis and comedogenesis. Retention hyperkeratosis in closed comedones and inflammatory papules is attributable to a disorder of terminal keratinocyte differentiation. Propionibacterium acnes, by acting on TLR-2, may stimulate the secretion of cytokines, such as interleukin (IL)-6 and IL-8 by follicular keratinocytes and IL-8 and -12 in macrophages, giving rise to inflammation. Certain P. acnes species may induce an immunological reaction by stimulating the production of sebocyte and keratinocyte antimicrobial peptides, which play an important role in the innate immunity of the follicle. Qualitative changes of sebum lipids induce alteration of keratinocyte differentiation and induce IL-1 secretion, contributing to the development of follicular hyperkeratosis. High glycemic load food and milk may induce increased tissue levels of 5alpha-dihydrotestosterone. These new aspects of acne pathogenesis lead to the considerations of possible customized therapeutic regimens. Current research is expected to lead to innovative treatments in the near future.

Pharmacotherapy of acne

BACKGROUND

Acne results from the interplay of several pathophysiologic factors, in particular seborrhoea, follicular hyperkeratosis, propionibacteria and inflammation. Recently, it has become clear that inflammatory events are important not only in the course, but also in the initiation of the disease.

OBJECTIVE

The study undertook an evaluation of the effectiveness of currently available pharmacotherapeutic treatment options for acne.

METHODS

After a Medline-based literature search, this article critically reviewed substances used topically (among others, retinoids, antimicrobials, salicylic acid and azelaic acid) and systemically (antibiotics, isotretinoin, hormones and zinc) as well as their combinations with respect to pharmacology, clinical efficacy and side effects.

RESULTS

Modern acne pharmacotherapy provides substances that antagonize one or more of the major pathophysiologic factors of acne. When the clinical picture but also patients' motivation and wishes are appropriately considered, current pharmacotherapy of acne is rational and effective.