Pharmacotherapy of acne

Less polar ginsenosides have better protective effects on mice infected by Listeria monocytogenes

Listeria monocytogenes widely exists in the natural environment and does great harm, which can cause worldwide public safety problem. Infection with L. monocytogenes can cause rapid death of Kupffer cell (KCs) in liver tissue and liver damage. American ginseng saponins is a natural compound in plants, which has great potential in inhibiting L. monocytogenes infection. Therefore, American ginseng stem-leaf saponins (AGS) and American ginseng heat-transformed saponins (HTS) were used as raw materials to study their bacteriostatic experiments in vivo and in vitro. In this experiment, female Kunming mice were randomly divided into five groups: control group, negative group, AGS group, HTS group (10 mg/kg/day in an equal volume via gastric administration) and penicillin group, each group containing six mice. Profiles AGS and HTS components were evaluated by high-performance liquid chromatography (HPLC) analysis. The bacteriostatic effect of AGS and HTS on L. monocytogenes was evaluated by inhibition zone test, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). The bacteriostatic effect of AGS and HTS pretreatment on mice infected with L. monocytogenes were studies by animal experimental. The results showed that the content of polar saponins in AGS was 0.81 ± 0.003 mg/mg, less polar saponins was 0.08 ± 0.02 mg/mg, the content of polar saponins in HTS was 0.10 ± 0.01 mg/mg, less polar saponins was 0.76 ± 0.02 mg/mg. The in vitro bacteriostatic diameter of HTS (16.6 ± 0.8 mm) is large than that of AGS (10.2 ± 1.2 mm). AGS and HTS pretreatment could reduce the colony numbers in the livers of mice infected with Listeria monocytogenes. The levels of alanine aminotransferase (ALT), IL-1β, IL-6, TNF-α and IFN-γ in the livers of mice in the pretreatment group were significantly lower than those in the negative group. There were obvious leukoplakia, calcification and other liver damage on the liver surface in the negative control group, and obvious inflammatory cell infiltration in HE sections. AGS and HTS pretreatment can reduce liver injury caused by L. monocytogenes and protect the liver. Compared with AGS, HTS has higher content of less polar saponins and better bacteriostatic effect in vitro. The count of bacterial in liver tissue of HTS group was significantly lower, the survival rate was significantly higher than that of AGS group. Less polar saponins had better bacteriostatic effect. Collectively, less polar saponins pretreatment has a protective effect on mice infected with L. monocytogenes, to which alleviated liver damage, improved anti-inflammatory ability and immunity of the body, protected liver may contribute.

Medication adherence and its possible associated factors in patients with acne vulgaris: A cross-sectional study of 200 patients in Iran

There are several etiologic factors involved in the pathogenesis of acne vulgaris. Therefore, current treatment guidelines recommend applying different classes of medications for it. This makes medication adherence a challenging issue in acne patients. The current study was designed to assess medication adherence and its possible associated factors in patients with acne vulgaris. This study was performed on patients with acne vulgaris in two dermatology clinics of Imam Khomeini Hospital and Razi Hospital. A validated questionnaire (ECOB, Elaboration d'un outil d'evaluation de l'observance des traitements medicamenteux) was applied to evaluate adherence to topical and oral therapies. We assessed relationship between patients' medication adherence and their sociodemographic, medication, and medical histories. A total of 200 patients, 136 females (68%), and 64 males (32%), with a mean age of 22 years were entered into the study. Overall, only 30 out of 200 patients (15%) were adherent to their treatments. Based on the bivariate analyses, food exacerbations, and severity of the disease by the patient's opinion was significantly associated with overall medication adherence (P = .03). Moreover, patients who were more adherent to topical treatment were more adherent to systemic treatment, as well (P = .007). The current study showed that treatment adherence was very low among patients with acne vulgaris. It is recommended to educate patients on the proper use of anti-acne medications. Besides, it is highly recommended that physicians and pharmacists use ECOB questionnaire regularly to guide patients accurately with the use of their drug regimens.

Topical azelaic acid, salicylic acid, nicotinamide, sulphur, zinc and fruit acid (alpha-hydroxy acid) for acne

BACKGROUND

Acne is an inflammatory disorder with a high global burden. It is common in adolescents and primarily affects sebaceous gland-rich areas. The clinical benefit of the topical acne treatments azelaic acid, salicylic acid, nicotinamide, sulphur, zinc, and alpha-hydroxy acid is unclear.

OBJECTIVES

To assess the effects of topical treatments (azelaic acid, salicylic acid, nicotinamide, zinc, alpha-hydroxy acid, and sulphur) for acne.

SEARCH METHODS

We searched the following databases up to May 2019: the Cochrane Skin Group Specialised Register, CENTRAL, MEDLINE, Embase, and LILACS. We also searched five trials registers.

SELECTION CRITERIA

Clinical randomised controlled trials of the six topical treatments compared with other topical treatments, placebo, or no treatment in people with acne.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. Key outcomes included participants' global self-assessment of acne improvement (PGA), withdrawal for any reason, minor adverse events (assessed as total number of participants who experienced at least one minor adverse event), and quality of life.

MAIN RESULTS

We included 49 trials (3880 reported participants) set in clinics, hospitals, research centres, and university settings in Europe, Asia, and the USA. The vast majority of participants had mild to moderate acne, were aged between 12 to 30 years (range: 10 to 45 years), and were female. Treatment lasted over eight weeks in 59% of the studies. Study duration ranged from three months to three years. We assessed 26 studies as being at high risk of bias in at least one domain, but most domains were at low or unclear risk of bias. We grouped outcome assessment into short-term (less than or equal to 4 weeks), medium-term (from 5 to 8 weeks), and long-term treatment (more than 8 weeks). The following results were measured at the end of treatment, which was mainly long-term for the PGA outcome and mixed length (medium-term mainly) for minor adverse events. Azelaic acid In terms of treatment response (PGA), azelaic acid is probably less effective than benzoyl peroxide (risk ratio (RR) 0.82, 95% confidence interval (CI) 0.72 to 0.95; 1 study, 351 participants), but there is probably little or no difference when comparing azelaic acid to tretinoin (RR 0.94, 95% CI 0.78 to 1.14; 1 study, 289 participants) (both moderate-quality evidence). There may be little or no difference in PGA when comparing azelaic acid to clindamycin (RR 1.13, 95% CI 0.92 to 1.38; 1 study, 229 participants; low-quality evidence), but we are uncertain whether there is a difference between azelaic acid and adapalene (1 study, 55 participants; very low-quality evidence). Low-quality evidence indicates there may be no differences in rates of withdrawal for any reason when comparing azelaic acid with benzoyl peroxide (RR 0.88, 95% CI 0.60 to 1.29; 1 study, 351 participants), clindamycin (RR 1.30, 95% CI 0.48 to 3.56; 2 studies, 329 participants), or tretinoin (RR 0.66, 95% CI 0.29 to 1.47; 2 studies, 309 participants), but we are uncertain whether there is a difference between azelaic acid and adapalene (1 study, 55 participants; very low-quality evidence). In terms of total minor adverse events, we are uncertain if there is a difference between azelaic acid compared to adapalene (1 study; 55 participants) or benzoyl peroxide (1 study, 30 participants) (both very low-quality evidence). There may be no difference when comparing azelaic acid to clindamycin (RR 1.50, 95% CI 0.67 to 3.35; 1 study, 100 participants; low-quality evidence). Total minor adverse events were not reported in the comparison of azelaic acid versus tretinoin, but individual application site reactions were reported, such as scaling. Salicylic acid For PGA, there may be little or no difference between salicylic acid and tretinoin (RR 1.00, 95% CI 0.92 to 1.09; 1 study, 46 participants; low-quality evidence); we are not certain whether there is a difference between salicylic acid and pyruvic acid (1 study, 86 participants; very low-quality evidence); and PGA was not measured in the comparison of salicylic acid versus benzoyl peroxide. There may be no difference between groups in withdrawals when comparing salicylic acid and pyruvic acid (RR 0.89, 95% CI 0.53 to 1.50; 1 study, 86 participants); when salicylic acid was compared to tretinoin, neither group had withdrawals (both based on low-quality evidence (2 studies, 74 participants)). We are uncertain whether there is a difference in withdrawals between salicylic acid and benzoyl peroxide (1 study, 41 participants; very low-quality evidence). For total minor adverse events, we are uncertain if there is any difference between salicylic acid and benzoyl peroxide (1 study, 41 participants) or tretinoin (2 studies, 74 participants) (both very low-quality evidence). This outcome was not reported for salicylic acid versus pyruvic acid, but individual application site reactions were reported, such as scaling and redness. Nicotinamide Four studies evaluated nicotinamide against clindamycin or erythromycin, but none measured PGA. Low-quality evidence showed there may be no difference in withdrawals between nicotinamide and clindamycin (RR 1.12, 95% CI 0.49 to 2.60; 3 studies, 216 participants) or erythromycin (RR 1.40, 95% CI 0.46 to 4.22; 1 study, 158 participants), or in total minor adverse events between nicotinamide and clindamycin (RR 1.20, 95% CI 0.73 to 1.99; 3 studies, 216 participants; low-quality evidence). Total minor adverse events were not reported in the nicotinamide versus erythromycin comparison. Alpha-hydroxy (fruit) acid There may be no difference in PGA when comparing glycolic acid peel to salicylic-mandelic acid peel (RR 1.06, 95% CI 0.88 to 1.26; 1 study, 40 participants; low-quality evidence), and we are uncertain if there is a difference in total minor adverse events due to very low-quality evidence (1 study, 44 participants). Neither group had withdrawals (2 studies, 84 participants; low-quality evidence).

AUTHORS' CONCLUSIONS

Compared to benzoyl peroxide, azelaic acid probably leads to a worse treatment response, measured using PGA. When compared to tretinoin, azelaic acid probably makes little or no difference to treatment response. For other comparisons and outcomes the quality of evidence was low or very low. Risk of bias and imprecision limit our confidence in the evidence. We encourage the comparison of more methodologically robust head-to-head trials against commonly used active drugs.

An update on formulation strategies of benzoyl peroxide in efficient acne therapy with special focus on minimizing undesired effects

Benzoyl peroxide (BPO) in the form of over the counter monotherapeutics or prescription-only combinations is a key component of topical acne therapy, but its unfavourable side effect profile reduces the therapeutic value of this compound. Various galenic approaches have been pursued to resolve this ambivalence, but only a few have managed to enter the market. This article aims to give a comprehensive overview of the published experimental vehicle systems and to identify the fundamental rationales. With regard to the formulation, an increase in the tolerability of BPO can essentially be achieved by combining BPO with re-fattening and moisturizing substances, by incorporating it and controlling its release, as well as by targeted deposition of the active ingredient at the site of action, i.e. drug targeting. Recently, novel particulate formulations have been proposed that combine several of these design principles and are expected to bring new developments in this dynamic field of research.

Correlation Between Lipid Profile and Acne Vulgaris

Background and Aim

Acne is a common skin disease resulting from a complex interaction of various pathogenetic factors. The aim of this study was to find out lipid profile abnormalities in acne vulgaris patients.

Material and Methods

This descriptive analytic cross-sectional study was conducted on 45 acne patients and 45 age- and sex-matched healthy controls to assess plasma total cholesterol (TC), low-density lipoprotein cholesterol (LDL), high-density lipoprotein cholesterol (HDL), and triglyceride (TG) levels.

Results

We showed a higher cholesterol level in acne patients (P=0.025), particularly in men (P=0.04). Other plasma lipids including TG, LDL, and HDL in male and female patients were higher compared to controls, but this is not statistically significant.

Discussion and Conclusion

In conclusion, lipid profile was altered in our patients, with high cholesterol level as the commonest derangement, particularly in men. Therefore, screening for lipid profile abnormalities could be considered in the treatment of acne patients.

Antimicrobial activities of Asian ginseng, American ginseng, and notoginseng

Asian ginseng (Panax ginseng C.A. Meyer), American ginseng (Panax quinquefolius) and notoginseng (Panax notoginseng) are the three most commonly used ginseng botanicals in the world. With the increasing interests on antimicrobial properties of plants, the antimicrobial activities of ginseng species have been investigated by a number of researchers worldwide. This overview interprets our present knowledge of the antimicrobial activities of the three ginseng species and some of their bioactive components against pathogenic bacteria (Pseudomonas aeruginosa, Helicobacter pylori, Staphylococcus aureus, Escherichia coli, Propionibacterium acnes, et al.) and fungi (Candida albicans, Fusarium oxysporum, et al). Ginsenosides, polysaccharides, essential oil, proteins, and panaxytriol are all might responsible for the antimicrobial activities of ginseng. The antimicrobial mechanisms of ginseng components could be summarized to the following points: (a) inhibit the microbial motility and quorum-sensing ability; (b) affect the formation of biofilms and destroy the mature biofilms, which can weaken the infection ability of the microbes; (c) perturb membrane lipid bilayers, thus causing the formation of pores, leakages of cell constituents and eventually cell death; (d) stimulate of the immune system and attenuate microbes induced apoptosis, inflammation, and DNA damages, which can protect or help the host fight against microbial infections; and (e) inhibit the efflux of antibiotics that can descend the drug resistance of the microbial. The collected information might facilitate and guide further studies needed to optimize the use of ginseng and their components to improve microbial food safety and prevent or treat animal and human infections.

Prolonged Serum Alanine Aminotransferase Elevation Associated with Isotretinoin Administration

Isotretinoin is a highly effective oral retinoid derivative for severe forms of acne. Despite its high margin of safety, isotretinoin carries a risk of teratogenicity and mild to massive elevations of serum cholesterol and triglyceride levels, as well as infrequent transaminitis. Liver dysfunction induced by isotretinoin is rare but it poses a management dilemma. We describe a 16-year-old male in whom alanine aminotransferase (ALT) rose from a baseline of 13 to 288 U/L after 20 weeks of treatment with 1.0-1.4 mg/kg of oral isotretinoin daily. Though the patient remained asymptomatic, ALT levels did not return to normal limits for approximately 8 months after discontinuation of therapy, an observation that has not been documented in the literature. When oral isotretinoin was readministered for intractable facial acne 3 years later, liver enzymes remained normal throughout the course of therapy. Although the pathogenesis and prognosis of retinoid-induced hepatotoxicity are unknown, this case illustrates that isotretinoin may be safely readministered after normalization of liver function tests.

Synchronizing Pharmacotherapy in Acne with Review of Clinical Care

Acne is a chronic inflammatory skin disease that involves the pathogenesis of four major factors, such as androgen-induced increased sebum secretion, altered keratinization, colonization of Propionibacterium acnes, and inflammation. Several acne mono-treatment and combination treatment regimens are available and prescribed in the Indian market, ranging from retinoids, benzoyl peroxide (BPO), anti-infectives, and other miscellaneous agents. Although standard guidelines and recommendations overview the management of mild, moderate, and severe acne, relevance and positioning of each category of pharmacotherapy available in Indian market are still unexplained. The present article discusses the available topical and oral acne therapies and the challenges associated with the overall management of acne in India and suggestions and recommendations by the Indian dermatologists. The experts opined that among topical therapies, the combination therapies are preferred over monotherapy due to associated lower efficacy, poor tolerability, safety issues, adverse effects, and emerging bacterial resistance. Retinoids are preferred in comedonal acne and as maintenance therapy. In case of poor response, combination therapies BPO-retinoid or retinoid-antibacterials in papulopustular acne and retinoid-BPO or BPO-antibacterials in pustular-nodular acne are recommended. Oral agents are generally recommended for severe acne. Low-dose retinoids are economical and have better patient acceptance. Antibiotics should be prescribed till the inflammation is clinically visible. Antiandrogen therapy should be given to women with high androgen levels and are added to regimen to regularize the menstrual cycle. In late-onset hyperandrogenism, oral corticosteroids should be used. The experts recommended that an early initiation of therapy is directly proportional to effective therapeutic outcomes and prevent complications.

Evaluation of antibacterial and anti-inflammatory activities of less polar ginsenosides produced from polar ginsenosides by heat-transformation

Ginsenosides are the major active constituents in both white and red American ginseng (AG), and their pharmacological effects on central nervous, cardiovascular, and endocrine systems have been well elucidated. However, the anti-Propionibacterium acnes (P. acnes) activity of them is still unknown. In this study, 5 ginsenosides enriched fractions were obtained from the total ginsenosides extract of AG roots (TAG) by resin adsorption and heat-transformation. Resin purification decreased the total polyphenol (TP) content in the fractions. However, heat treatment increased the TP content and induced extensive conversion of the polar ginsenosides (Rg1, Re, Rb1, Rc, Rb2, Rd, and Gyp XVII) to less polar compounds (Rg2, Rg3, Rg6/F4, Rs3, and Rg5/Rk1). Only the heat-treated fraction from 65% methanol elution of the HP-20 column (HPHF) showed antibacterial activity against P. acnes (ATCC11827, MIC, 128 μg/mL; ATCC6919 MIC, 64 μg/mL), S. epidermidis (MIC, 4100 μg/mL) and S. aureus (MIC, 15000 μg/mL). In the anti-inflammatory activity assay, 10 μg/mL of HPHF significantly (P < 0.05) inhibited NO production in LPS-stimulated RAW264.7 cells. These results suggest that less polar ginsenosides enriched fraction HPHF obtained from AG might be useful to develop new types of antibacterial substances and new skin care cosmetics for acne prevention and therapy.

Minocycline for acne vulgaris: efficacy and safety

BACKGROUND

Minocycline is an oral antibiotic used for acne vulgaris. Its use has lessened due to safety concerns (including potentially irreversible pigmentation), a relatively high cost, and no evidence of any greater benefit than other acne treatments. A modified-release version of minocycline is being promoted as having fewer side-effects.

OBJECTIVES

To assess new evidence on the effects of minocycline for acne vulgaris.

SEARCH METHODS

Searches were updated in the following databases to November 2011: the Cochrane Skin Group Specialised Register, CENTRAL in The Cochrane Library, MEDLINE (from 1946), EMBASE (from 1974), and LILACS (from 1982). We also searched trials registers and checked reference lists for further references to relevant randomised controlled trials (RCTs).The Cochrane Skin Group's Trials Search Co-ordinator undertook searches exploring minocycline's adverse effects in EMBASE and MEDLINE in February 2012.

SELECTION CRITERIA

We selected randomised controlled trials (RCTs) comparing minocycline, at any dose, to an active or a placebo control, in participants with inflammatory acne vulgaris. For adverse effects, we selected additional studies that reported the number of adverse effects and the number of participants treated.

DATA COLLECTION AND ANALYSIS

Outcome measures used in the trials included lesion counts, acne grades/severity scores, doctors' and participants' global assessments, adverse effects, and dropout rates. Two authors independently assessed the quality of each study. Effect sizes were calculated, and meta-analyses were undertaken where possible.Sixteen studies met the inclusion criteria for the review of adverse effects.

MAIN RESULTS

We included 12 new RCTs for this update, giving a total of 39 RCTs (6013 participants). These additional 12 RCTs have not changed the original conclusions about the clinical efficacy of minocycline.The identified RCTs were generally small and poor quality. Meta-analysis was rarely possible because of the lack of data and different outcome measures and trial durations. Although minocycline was shown to be an effective treatment for moderate to moderately-severe acne vulgaris, there was no evidence that it is better than any of the other commonly-used acne treatments. One company-sponsored RCT found minocycline to be less effective than combination treatment with topical erythromycin and zinc. No trials have been conducted using minocycline in those participants whose acne is resistant to other therapies. Also, there is no evidence to guide what dose should be used.The adverse effects studies must be interpreted with caution. The evidence suggests that minocycline is associated with more severe adverse effects than doxycycline. Minocycline, but not other tetracyclines, is associated with lupus erythematosus, but the risk is small: 8.8 cases per 100,000 person-years. The risk of autoimmune reactions increases with duration of use. The evidence does not support the conclusion that the more expensive extended-release preparation is safer than standard minocycline preparations.

AUTHORS' CONCLUSIONS

Minocycline is an effective treatment for moderate to moderately-severe inflammatory acne vulgaris, but there is still no evidence that it is superior to other commonly-used therapies. This review found no reliable evidence to justify the reinstatement of its first-line use, even though the price-differential is less than it was 10 years ago. Concerns remain about its safety compared to other tetracyclines.

Efficacy and safety of topical nadifloxacin and benzoyl peroxide versus clindamycin and benzoyl peroxide in acne vulgaris: A randomized controlled trial

Background:

Topical therapy with comedolytics and antibiotics are often advocated for mild and moderate severity acne vulgaris. Nadifloxacin, a new fluoroquinolone with anti-Propionibacterium acnes activity and additional anti-inflammatory activity, is approved for use in acne. This randomized controlled assessor blind trial compared the clinical effectiveness and safety of eight weeks therapy of nadifloxacin 1% versus clindamycin 1% as add-on therapy to benzoyl peroxide (2.5%) in mild to moderate grade acne.

Materials and Methods:

The efficacy parameters were changes in the total, inflammatory and non-inflammatory lesion counts, Investigator Global Assessment (IGA), and Cardiff Acne Disability Index (CADI) scales from baseline to study end (eight weeks). All treatment emergent dermatological adverse events were evaluated for safety assessment.

Results:

Out of 84 randomized subjects (43-nadifloxacin arm) and (41-clindamycin) 42 in nadifloxacin group, 37 in clindamycin group completed the study. Reduction from baseline of total, inflammatory and non-inflammatory lesion counts were highly significant in both the groups (P<0.0001), but between group differences were not significant. Significant improvement in CADI and IGA scales were noted in both groups. Between-group comparison showed no significant differences. The safety and tolerability profile of both regimens were good and statistically comparable.

Conclusions:

Topical nadifloxacin, a new fluoroquinolone is effective, tolerable, and safe for mild o moderate facial acne. Its clinical effectiveness is comparable to clindamycin when used as add-on therapy to benzoyl peroxide.

Treating acne with antibiotic-resistant bacterial colonization

INTRODUCTION

Acne is a chronic skin disorder of the pilosebaceous unit; it has a multifactorial pathogenesis. Propionibacterium acnes within the follicle is considered to be a triggering factor of inflammation in acne. Antibiotics have been the primary treatment against P. acnes for more than 40 years. However, a gradual increase in the prevalence of antibiotic-resistant strains of P. acnes has been observed.

AREAS COVERED

This review discusses the pathophysiology of antibiotic-resistant acne development. It focuses on strategies to minimize the development of resistance and, most importantly, confront the development of antibiotic-resistant acne. The literature search was conducted up to August 2010, using the search terms 'acne', 'antibiotic-resistant acne' and 'bacterial resistance'.

EXPERT OPINION

Antibiotic-resistant acne is a real phenomenon. Strategies to prevent and confront it should include not only the use of certain treatment regimens but also rational prescribing policies, combination therapies, use of antibacterial non-antibiotic agents and treatment options targeting all the pathogenetic components of acne. Benzoyl-peroxide-based treatment is the most evidence-based approach. Oral isotretinoin remains the most efficacious option for severe acne.

Vitamin D, disease and therapeutic opportunities

The discovery of the vitamin D endocrine system and a receptor for the hormonal form, 1α,25-dihydroxyvitamin D(3), has brought a new understanding of the relationship between vitamin D and metabolic bone diseases, and has also established the functions of vitamin D beyond the skeleton. This has ushered in many investigations into the possible roles of vitamin D in autoimmune diseases, cardiovascular disorders, infectious diseases, cancers and granuloma-forming diseases. This article presents an evaluation of the possible roles of vitamin D in these diseases. The potential of vitamin D-based therapies in treating diseases for which the evidence is most compelling is also discussed.

Innovative uses for zinc in dermatology

Severe zinc deficiency states, such as acrodermatitis enteropathica, are associated with a variety of skin manifestations, such as perioral, acral, and perineal dermatitis. These syndromes can be reversed with systemic zinc repletion. In addition to skin pathologies that are clearly zinc-dependent, many dermatologic conditions (eg, dandruff, acne, and diaper rash) have been associated and treated with zinc. Success rates for treatment with zinc vary greatly depending on the disease, mode of administration, and precise zinc preparation used. With the exception of systemic zinc deficiency states, there is little evidence that convincingly demonstrates the efficacy of zinc as a reliable first-line treatment for most dermatologic conditions. However, zinc may be considered as an adjunctive treatment modality. Further research is needed to establish the indications for zinc treatment in dermatology, optimal mode of zinc delivery, and best type of zinc compound to be used.

Identification of a unique subset of 2-methylene-19-nor analogs of vitamin D with comedolytic activity in the rhino mouse

The active metabolite of vitamin D, 1,25-dihydroxyvitamin D(3) (1,25(OH)(2)D(3)), and a series of 2-methylene-19-nor analogs of 1,25(OH)(2)D(3) were evaluated for their ability to reduce the size of utricles (comedolytic activity) in a rhino mouse model of acne. All analogs tested, as well as the native hormone, increased the skin epidermal thickness. In contrast, only a subset of analogs that lacked a full side chain and 25-hydroxyl group were found to possess comedolytic activity. A reduction in comedone area could be achieved without adversely affecting serum calcium levels. Although all compounds that contained a side chain ranging from 2 to 5 carbons in length had similar potency as comedolytic agents, increasing the length of the side chain resulted in a progressive increase in calcemic liability. Dose-response studies of the comedolytic analogs showed that an increase in epidermal thickness was achieved at a lower dose than that needed to induce comedolysis. Thus, we have identified a unique subset of vitamin D analogs that produce comedolysis in the absence of hypercalcemia. Further, the activity of vitamin D analogs in causing epidermal hyperproliferation has been distinguished from that resulting in a reduction in utricle size.

Emerging drugs for acne

Acne vulgaris is a common skin disorder that affects most individuals at some point in their lives. It may result in significant morbidity, including cutaneous scarring and psychological impairment. Current treatments include topical retinoids, benzoyl peroxide, topical and systemic antibiotics, and systemic isotretinoin. There are growing concerns of rising antibiotic resistance, significant side effects of isotretinoin therapy, and lack of safe and effective treatment for pregnant females. Recent advances in the pathogenesis of acne have led to a greater understanding of the underlying inflammatory mechanisms and the role the Propionibacterium acnes and biofilms. This has led to the development of new therapeutic targets. This article reviews emerging treatments of acne, including topical picolinic acid, topical antibiotic dapsone, systemic zinc salts, oral antibiotic lymecycline, new formulations of and synergistic combinations of benzoyl peroxide, photodynamic therapy with topical photosensitizers and potential acne vaccines.