Evaluation of the antibacterial efficacy of diesters of azelaic acid

1H-NMR and LC-MS Based Metabolomics Analysis of Potato (Solanum tuberosum L.) Cultivars Irrigated with Fly Ash Treated Acid Mine Drainage

¹H NMR and LC-MS, commonly used metabolomics analytical platforms, were used to annotate the metabolites found in potato (Solanum tuberosum L.) irrigated with four different treatments based on FA to AMD ratios, namely: control (0% AMD; tap water), 1:1 (50% AMD), 3:1 (75% AMD is 75% FA: AMD), and 100% AMD (untreated). The effects of stress on plants were illustrated by the primary metabolite shifts in the region from δ_H 0.0 to δ_H 4.0 and secondary metabolites peaks were prominent in the region ranging from δ_H 4.5 to δ_H 8.0. The 1:3 irrigation treatment enabled, in two potato cultivars, the production of significantly high concentrations of secondary metabolites due to the 75% FA: AMD content in the irrigation mixture, which induced stress. The findings suggested that 1:1 irrigation treatment induced production of lower amounts of secondary metabolites in all crops compared to crops irrigated with untreated acid mine drainage treatment and with other FA-treated AMD solutions.

Azelaic acid loaded chitosan and HPMC based hydrogels for treatment of acne: formulation, characterization, in vitro-ex vivo evaluation

In this study, hydrogels containing azelaic acid were developed using chitosan or HPMC (1-7%) for local treatment of acne vulgaris. Physicochemical properties such as viscosity, pH and mechanical properties were evaluated. In vitro release and ex vivo permeability studies were performed using Franz diffusion cell system. The pH of the hydrogels were highly compatible with the skin pH and varied between 4.38-5.84. The cumulative release percentages of the hydrogels at the end of 6 hours were 65-78%, whereas the marketed product yielded 50% drug release. According to the ex vivo permeability results, azelaic acid accumulated in the skin were found to be 9.38 ± 0.65% (marketed cream), 19.53 ± 1.06% (K3), 10.96 ± 1.91% (H6). The antiacne studies with Cutibacterium acnes revealed that K3 (29.45 ± 0.95) and H6 (32.35 ± 0.15) had higher inhibition zones compared to the marketed cream (24.50 ± 0.90). Additionally, the gels were found to be highly stable as a result of the stability studies for 6 months. Among the hydrogels that were prepared based on experimental findings, K3 (3% Chitosan) and H6 (6% HPMC) represented elevated in vitro release profile, higher permeability and increased antiacne activity. The findings of this research suggest that the developed hydrogels might be an alternative to the marketed product.

Acid-base combination principles for preparation of anti-acne dissolving microneedles loaded with azelaic acid and matrine

To overcome the poor solubility, skin irritation, and low permeability of azelaic acid (AZA) existed on the marketed formulations, a co-drug principle via matrine (MAT) was adopted to prepare anti-acne dissolving microneedles (DMNs). The formula was optimized according to the solubility and antibacterial activity of novel ionic salt. The results indicated solubilization of AZA could be achieved at a molar ratio between AZA and MAT was 1:1. Meanwhile, synergistic antibacterial and anti-irritative properties were acquired. The matrix materials were composed of sodium carboxymethyl cellulose (CMC), polyvinylpyrrolidone (PVP), and trehalose. And drug loadings of AZA and MAT in DMNs were 201.88 ± 4.81 µg and 259.71 ± 1.72 µg, respectively. After insertion into porcine skin for 10 h, the cumulative permeability of AZA and MAT were 68.16% ± 3.79% and 57.37 ± 5.17%, respectively, while just 4.13 ± 0.39% (p < 0.01) was detected for commercially available AZA gel. In vitro antibacterial experiment, bacteriostatic rates of DMNs were all above 95% for Staphylococcus aureus, Staphylococcus epidermidis, and Propionibacterium acnes. Besides, DMNs exhibited no cytotoxicity and skin irritation. In conclusion, combination between AZA and MAT addressed shortcomings of AZA, and made it easier, safer, and more effective in acne treatment.

Cosmeceutical Aptitudes of Azelaic Acid

BACKGROUND

Azelaic acid (AZA) is a white crystalline dicarboxylic acid naturally found in grains, rye and barley. AZA has substantial biological and therapeutic abilities (viz a viz) its anti-inflammatory, anti-oxidant, anti-keratinizing, anti-microbial properties, etc. which contribute to its applicability in the management of mild to harsh dermatological complications (acne, rosacea, dermatitis, hyper-pigmentation, carcinomas, etc.). AZA has shown its effectiveness against varied non-inflammatory and inflammatory lesions by normalizing the hyper-keratinization statie and attenuating the increased levels of microbial content. Topically AZA, either alone or in conjunction with other active moieties, has proved to be effective in preventing acne and several other hyper-pigmentary conditions.

OBJECTIVES

Chronic applicability of AZA has been evidenced with the effects like itching, burning, stinging, redness, etc. To deal with the former issues, research is being conducted to substitute the conventional formulations with novel preparations (liposome's, niosomes, micro sponges, lipid nanocarriers, etc.), which could enhance the overall pharmaceutical and pharmacological profile of the drug.

CONCLUSION

This article is an attempt to highlight the basic physiochemical properties of AZA, its physiological role (especially in dermatology), various commercial preparations and recent novel approaches that are in research with an aim to augment the therapeutic and safety profile of AZA.

Metal-Organic-Framework-Based Materials for Antimicrobial Applications

To address the serious threat of bacterial infection to public health, great efforts have been devoted to the development of antimicrobial agents for inhibiting bacterial growth, preventing biofilm formation, and sterilization. Very recently, metal-organic frameworks (MOFs) have emerged as promising materials for various antimicrobial applications owing to their different functions including the controlled/stimulated decomposition of components with bactericidal activity, strong interactions with bacterial membranes, and formation of photogenerated reactive oxygen species (ROS) as well as high loading and sustained releasing capacities for other antimicrobial materials. This review focuses on recent advances in the design, synthesis, and antimicrobial applications of MOF-based materials, which are classified by their roles as component-releasing (metal ions, ligands, or both), photocatalytic, and chelation antimicrobial agents as well as carriers or/and synergistic antimicrobial agents of other functional materials (antibiotics, enzymes, metals/metal oxides, carbon materials, etc.). The constituents, fundamental antimicrobial mechanisms, and evaluation of antimicrobial activities of these materials are highlighted to present the design principles of efficient MOF-based antimicrobial materials. The prospects and challenges in this research field are proposed.

The versatility of azelaic acid in dermatology

Azelaic acid has numerous pharmacological uses in dermatology. Its anti-inflammatory and anti-oxidant properties are thought to correlate with its efficacy in papulopustular rosacea and acne vulgaris, amongst other cutaneous conditions. We conducted a review of the literature on the use of azelaic acid in dermatology using key terms 'acne', 'azelaic acid', 'dermatology', 'melasma', 'rosacea', searching databases such as MEDLINE, EMBASE and PubMed. Only articles in English were chosen. The level of evidence was evaluated and selected accordingly listing the studies with the highest level of evidence first using the Oxford Center of Evidence-Based Medicine 2011 guidance.This review found the strongest evidence supporting the use of azelaic acid in rosacea, followed by its use off-label in melasma followed by acne vulgaris. Weaker evidence is currently available to support the use of azelaic acid in several other conditions such as hidradenitis suppurativa, keratosis pilaris and male androgenic alopecia.Azelaic acid, as a monotherapy or in combination, could be an effective first-line or alternative treatment, which is well-tolerated and safe for a range of dermatological conditions.

A comparison of the effectiveness of azelaic and pyruvic acid peels in the treatment of female adult acne: a randomized controlled trial

Chemical peels are widely used as therapeutic agents in dermatology and cosmetology. This study aims to explore the differences in the effectiveness of azelaic and pyruvic acid peels in the treatment of acne vulgaris. Eligibility criteria for participants were: female gender, 18–25 years of age, no dermatological treatment within the last 12 months and mild to moderate papulopustular acne. We treated 120 young women (with a mean age of 22 years old) with six peeling sessions at 2-week intervals. In the parallel clinical study design, one randomized group (n = 60, 50%) was treated using azelaic acid (AA), whereas the second group participated in pyruvic acid (PA) sessions. We evaluated the patients clinically twice (before and after treatment), using the Scale of Hellegren–Vincent Severity Symptoms to assess the acne diagnosis, and the Nati Analyzer to estimate the skin properties (oily skin, desquamation, porosity, and moisture). The clinical evaluation of the patients demonstrated a significant reduction of acne severity symptoms in both the AA and PA groups, after the peeling sessions. An effect was also found in terms of decreasing desquamation and the oiliness of the skin. PA showed a more significant reduction of greasy skin than AA. In conclusion, after the six peeling sessions using AA and PA, all patients showed better skin parameters in term of reduced oiliness and desquamation. Both AA and PA peelings are a safe and efficient treatment for mild acne, however, during the selection of one of the two acids, side effects, skin properties, and patients’ preferences should be taken into account. This study was registered in the ISRCTN registry (registration number ISRCTN79716614, 17/01/2020).

Metabolomics window into the role of acute kidney injury after coronary artery bypass grafting in diabetic nephropathy progression

Introduction

Metabolomics has emerged as a valuable tool to discover novel biomarkers and study the pathophysiology of diabetic nephropathy (DN). However, the effect of postoperative acute kidney injury (AKI) on diabetes mellitus (DM) to chronic DN progression has not been evaluated from the perspective of metabolomics.

Methods

A group of type 2 diabetes mellitus (T2DM) inpatients, who underwent off-pump coronary artery bypass grafting (CABG), were enrolled in our study. According to whether postoperative AKI occurred, patients were grouped in either the AKI group (AKI, n = 44) or the non-AKI group (NAKI, n = 44). Urine samples were collected from these patients before and 24 h after operation. Six patients from the AKI group and six patients from the NAKI group were chosen as the pilot cohort for untargeted metabolomics analysis, with the goal of identifying postoperative AKI-related metabolites. To understand the possible role of these metabolites in the chronic development of renal injury among T2DM patients, trans-4-hydroxy-L-proline and azelaic acid were quantified by targeted metabolomics analysis among 38 NAKI patients, 38 AKI patients, 46 early DN patients (DN-micro group), and 34 overt DN patients (DN-macro group).

Results

Untargeted metabolomics screened 61 statistically distinguishable metabolites in postoperative urine samples, compared with preoperative urine samples. Via Venn diagram analysis, nine of 61 were postoperative AKI-related metabolites, including trans-4-hydroxy-L-proline, uridine triphosphate, p-aminobenzoate, caffeic acid, adrenochrome, δ-valerolactam, L-norleucine, 5′-deoxy-5′-(methylthio) adenosine, and azelaic acid. By targeted metabolomics analysis, the level of trans-4-hydroxy-L-proline increased gradually from the NAKI group to the AKI, DN-micro, and DN-macro groups. For azelaic acid, the highest level was found in the NAKI and DN-micro groups, followed by the DN-macro group. The AKI group exhibited the lowest level of azelaic acid.

Conclusions

The detection of urinary trans-4-hydroxy-L-proline after AKI could be treated as an early warning of chronic DN progression and might be linked to renal fibrosis. Urinary azelaic acid can be used to monitor renal function noninvasively in DM and DN patients. Our results identified markers of AKI on DM and the chronic progression of DN. In addition, the progression of DN was associated with AKI-like episodes occurring in DM.

Antibacterial applications of metal-organic frameworks and their composites

Metal-organic frameworks (MOFs) are porous coordination materials composed of multidentate organic ligands and metal ions or metal clusters. MOFs have the great potential to be utilized in antibacterial materials for biological, environmental, and food antimicrobial fields. In recent years, MOFs have been applied to various antibacterial fields due to their sustained release capability, porosity, and structural flexibility in combination with many chemicals and/or materials (such as nanoparticles, antibiotics, phytochemicals, and polymers). This review offers a detailed summary of the antibacterial applications of MOFs and their composites, focusing on the combination types of MOFs composites and the antibacterial effect in different applications. These applications are illustrated by the examples discussed in this review.

Topical, systemic and biologic therapies in hidradenitis suppurativa: pathogenic insights by examining therapeutic mechanisms

Hidradenitis suppurativa (HS) is a chronic inflammatory disease of the skin, manifesting in chronic, recurrent painful pustules, nodules, boils and purulent draining abscesses. Our current understanding of the pathogenesis of the disease is incomplete. This review aims to identify available treatment options in HS and discuss the pharmacological mechanisms through which such agents function. Identifying common pathways may inform our understanding of the pathogenesis of HS as well as identify future therapeutic targets. The pharmacological mechanisms implicated in topical therapies, antibiotic, hormonal, systemic immunomodulatory and biologic therapies for HS are discussed. Significant differences exist between agents and implicated pathways in therapy for mild and severe disease. This is an expression of the possible dichotomy in inflammatory pathways (and treatment responses) in HS. Studies involving monoclonal antibodies provide the greatest insight into what these specific mechanisms may be. Their variable levels of clinical efficacy compared with placebo bolsters the suggestion that differential inflammatory pathways may be involved in different presentations and severity of disease. Nuclear factor kappa B (NF-κB), tumor necrosis factor (TNF)-α and other innate immune mechanisms are strongly represented in treatments which are effective in mild to moderate disease in the absence of scarring or draining fistulae, however complex feed-forward mechanisms in severe disease respond to interleukin (IL)-1 inhibition but are less likely to respond to innate immune inhibition (through NF-κB or TNF-α) alone. It is unclear whether IL-17 inhibition will parallel TNF-α or IL-1 inhibition in effect, however it is plausible that small molecule targets (Janus kinase1 and phosphodiesterase 4) may provide effective new strategies for treatment of HS.

Identifying Antibacterial Compounds in Black Walnuts (Juglans nigra) Using a Metabolomics Approach

Black walnut (Juglans nigra L.) is one of the most economically valuable hardwood species and a high value tree for edible nut production in the United States. Although consumption of black walnut has been linked to multiple health-promoting effects (e.g., antioxidant, antimicrobial, anti-inflammatory), the bioactive compounds have not been systematically characterized. In addition, the associations between different black walnut cultivars and their health-promoting compounds have not been well established. In this study, the kernels of twenty-two black walnut cultivars selected for nut production by the University of Missouri Center for Agroforestry (Columbia, MO, USA) were evaluated for their antibacterial activities using agar-well diffusion assay. Among the selected cultivars, four black walnut cultivars (i.e., Mystry, Surprise, D.34, and A.36) exhibited antibacterial activity against a Gram-positive bacterium (Staphylococcus aureus), whereas other cultivars showed no effect on the inhibition of this bacterium. The antibacterial compounds showing the strongest activity were isolated with bioassay-guided purification and identified using a metabolomics approach. Six antibacterial bioactive compounds responsible for antimicrobial activity were successfully identified. Glansreginin A, azelaic acid, quercetin, and eriodictyol-7-O-glucoside are novel antibacterial compounds identified in the kernels of black walnuts. The metabolomics approach provides a simple and cost-effective tool for bioactive compound identification.

Lactobacillus paracasei metabolism of rice bran reveals metabolome associated with Salmonella Typhimurium growth reduction

AIMS

This study aimed to determine the effect of a cell-free supernatant of Lactobacillus paracasei ATCC 27092 with and without rice bran extract (RBE) on Salmonella Typhimurium 14028s growth, and to identify a metabolite profile with antimicrobial functions.

METHODS AND RESULTS

Supernatant was collected from overnight cultures of L. paracasei incubated in the presence (LP+RBE) or absence (LP) of RBE and applied to S. Typhimurium. LP+RBE reduced 13·1% more S. Typhimurium growth than LP after 16 h (P < 0·05). Metabolite profiles of LP and LP+RBE were examined using nontargeted global metabolomics consisting of ultra-high-performance liquid chromatography coupled with tandem mass spectrometry. A comparison of LP and LP+RBE revealed 84 statistically significant metabolites (P < 0·05), where 20 were classified with antimicrobial functions.

CONCLUSIONS

LP+RBE reduced S. Typhimurium growth to a greater extent than LP, and the metabolite profile distinctions suggested that RBE favourably modulates the metabolism of L. paracasei. These findings warrant continued investigation of probiotic and RBE antimicrobial activities across microenvironments and matrices where S. Typhimurium exposure is problematic.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study showed a novel metabolite profile of probiotic L. paracasei and prebiotic rice bran that increased antimicrobial activity against S. Typhimurium.

Mass spectrometry-based analysis of whole-grain phytochemicals

Whole grains are a rich source of several classes of phytochemicals, such as alkylresorcinols, benzoxazinoids, flavonoids, lignans, and phytosterols. A high intake of whole grains has been linked to a reduced risk of some major noncommunicable diseases, and it has been postulated that a complex mixture of phytochemicals works in synergy to generate beneficial health effects. Mass spectrometry, especially when coupled with liquid chromatography, is a widely used method for the analysis of phytochemicals owing to its high sensitivity and dynamic range. In this review, the current knowledge of the mass spectral properties of the most important classes of phytochemicals found in cereals of common wheat, barley, oats, and rye is discussed.

A prodrug approach to enhance azelaic acid percutaneous availability

Azelaic acid is a dicarboxylic acid compound used in treatment of acne vulgaris. However, high concentration (ca 20%) is needed to guarantee the drug availability in the skin. The latter increases the incidence of side effects such as local irritation. The prodrug strategy to enhance azelaic acid diffusion through skin was not reported before. Thus, a lipophilic prodrug of azelaic acid (diethyl azelate [DEA]) was synthesized and investigated to improve percutaneous availability of azelaic acid, with a subsequent full physical, chemical, and biological characterization. Expectedly, DEA exhibited a significant increase in diffusion compared to azelaic acid through silicone membrane. In contrast, the diffusion results through human stratum corneum (SC) displayed weaker permeation for DEA with expected retention in the SC. Therefore, a desorption study of DEA from SC was conducted to examine the reservoir behavior in SC. Results showed an evidence of sustained release behavior of DEA from SC. Consequently, enhancement of keratolytic effect is expected due to azelaic acid produced from enzymatic conversion of DEA released from SC.

Synthesis and characterization of a novel eco-friendly corrosion inhibition for mild steel in 1 M hydrochloric acid

The acid corrosion inhibition process of mild steel in 1 M HCl by azelaic acid dihydrazide has been investigated using electrochemical impedance spectroscopy (EIS), potentiodynamic polarization, open circuit potential (OCP) and electrochemical frequency modulation (EFM). Azelaic acid dihydrazide was synthesized, and its chemical structure was elucidated and confirmed using spectroscopic techniques (infrared, nuclear magnetic resonance and mass spectroscopy). Potentiodynamic polarization studies indicate that azelaic acid dihydrazide is a mixed-type inhibitor. The inhibition efficiency increases with increased inhibitor concentration and reaches its maximum of 93% at 5 × 10⁻³ M. The adsorption of the inhibitor on a mild steel surface obeys Langmuir’s adsorption isotherm. The effect of temperature on corrosion behavior in the presence of 5 × 10⁻³ M inhibitor was studied in the temperature range of 30–60 °C. The results indicated that inhibition efficiencies were enhanced with an increase in concentration of inhibitor and decreased with a rise in temperature. To inspect the surface morphology of inhibitor film on the mild steel surface, scanning electron microscopy (SEM) was used before and after immersion in 1.0 M HCl.

Gene expression profile of high-fat diet-fed C57BL/6J mice: in search of potential role of azelaic acid

High-fat diet (HFD) elevates circulatory fatty acids and influences glucose and fat metabolism. Azelaic acid (AzA), a naturally occurring α,ω-dicarboxylic acid in wheat, rye, barley, oat seeds and sorghum, has been reported to exert antidiabetic effects in HFD-induced type 2 diabetes mellitus (T2DM) C57BL/6J mice. The present study was undertaken to identify the genes that are differentially modulated by treatment with AzA in HFD-fed mice. Mice were fed HFD for 10 weeks and subjected to intragastric administration of 80 mg/kg body weight (BW) of AzA daily along with HFD from 11 to 15 weeks. Lipid profile, adipokines and cytokines were examined in the plasma/liver of mice. Whole genome profiling was performed in the liver of mice using microarray and validated by qRT-PCR, Western blot and immunohistochemical analyses. HFD intake resulted in significantly elevated lipids (except high-density lipoproteins), resistin, tumour necrosis factor alpha and interleukin-6 with marked reduction in adiponectin. Administration of AzA to HFD-fed mice significantly restored the lipids, adipokines and cytokines to near normal. Transcript profiling revealed that HFD intake activated the genes involved in stress response, cell cycle regulation and apoptosis. Treatment with AzA caused increased expression of genes involved in reactive oxygen species (ROS) scavenging, receptor-mediated signalling, transcription, protein modification and insulin signal transduction. AzA activates insulin signal molecules leading to insulin sensitivity. The ability of AzA to modulate the expression of these genes supports the notion that AzA is a promising drug candidate for the treatment of insulin resistance associated with T2DM.

Lipase-catalyzed synthesis of dilauryl azelate ester: process optimization by artificial neural networks and reusability study

An application of artificial neural networks (ANNs) to predict the performance of a lipase-catalyzed synthesis for esterification of dilauryl azelate ester was carried out.

A Zn azelate MOF: combining antibacterial effect

A novel biocompatible and bioactive zinc azelate metal–organic framework (BioMIL-5) was hydrothermally synthesized with interesting long-term antibacterial properties.

Effects of washing of the face with a mild facial cleanser formulated with sodium laureth carboxylate and alkyl carboxylates on acne in Japanese adult males

BACKGROUND/PURPOSE

Washing the face with a mild cleanser is generally recommended for acne care. Occasionally, the general public has the misconception that acne is exacerbated by cleansers and furthermore it has concerns about inducing skin irritation and xerosis by intensive washing. Recently, we developed a new cleanser based on sodium laureth carboxylate and alkyl carboxylates (AEC/soap) that cleans sebum well without penetrating the stratum corneum.

METHODS

We designed a controlled clinical trial conducted on adult Japanese males with moderate or less acne. Twenty subjects washed their faces with AEC/soap base cleanser twice a day for 4 weeks. Assessment of the efficacy was conducted prior to the start of the study, and at the end of weeks 2 and 4.

RESULTS

Significant improvement of the acne was observed within 2 weeks, and acne lesions were not detectable in 25% of the subjects at week 4. Sebum secretion levels on the skin significantly increased on the forehead, but significantly decreased on the cheek which correlated with the improvement. No complaints of dryness or irritation occurred during the study.

CONCLUSION

Washing the face twice a day with facial cleanser based on AEC/soap is an effective care for moderate or less grade facial acne.

Antimicrobial activity of untypical lipid compounds in the cuticular and internal lipids of four fly species

AIMS

This article describes the qualitative and quantitative analyses of untypical compounds in the cuticular and internal lipids of four dipteran species. For isolated compounds, antimicrobial activity against 18 reference strains of bacteria and fungi was determined.

METHODS AND RESULTS

In this study, gas chromatography (GC) combined with mass spectrometry (GC-MS) was used to analyse the surface and internal compounds of four fly species. Seven untypical compounds from both pre-imaginal and imaginal stages of examined insects were identified. Azelaic acid (AA) was the most abundant, while phenylacetic and phenylpropionic acids occurred in lower concentration. Minor quantities of sebacic acid, 2-methyl-2-hydroxybutanoic acid, tocopherol acetate and trace amounts of 2,4-decadienal were also detected. Tocopherol acetate was found only in cuticular lipids of Musca domestica larvae. Each compound was tested against several species of fungi and bacteria by determining minimal inhibitory concentration (MIC). Human pathogenic fungi were also investigated. Phenylpropionic acid showed the greatest antifungal activity. Bacterial strains were insensitive to the presence of identified compounds, apart from 2,4-decadienal which strongly inhibited bacterial growth.

CONCLUSIONS

This is the first time that the chemical composition and the antimicrobial activity of untypical compounds in the cuticular and internal lipids of four fly species has been analysed.

SIGNIFICANCE AND IMPACT OF THE STUDY

Determination of untypical compounds and their antimicrobial activity can effectively contribute to the knowledge concerning insect defence mechanisms.

Azelaic acid: Properties and mode of action

Acne is a common skin disorder that can be problematic for adults as well as for adolescents. It has several key pathophysiological features such as follicular hyperkeratosis, elevated Propionibacterium acnes proliferation, and reactive inflammation, all of which should be targeted for an optimal outcome. Azelaic acid (AzA) has profound anti-inflammatory, antioxidative effects, and is bactericidal against a range of Gram-negative and Gram-positive microorganisms as well, including antibiotic-resistant bacterial strains. In addition, AzA's antikeratinizing effects are inhibitory toward comedones. AzA is effective overall in targeting multiple causes of acne and has been proven to be well tolerated in numerous clinical trials.

Development and evaluation of a novel topical treatment for acne with azelaic acid-loaded nanoparticles

Azelaic acid (AzA) is used in the treatment of acne. However, side effects and low compliance have been associated with several topical treatments with AzA. Nanotechnology presents a strategy that can overcome these problems. Polymeric nanoparticles can control drug release and targeting and reduce local drug toxicity. The aim of this study was to produce and evaluate an innovative topical treatment for acne with AzA-loaded poly-DL-lactide/glycolide copolymer nanoparticles. A soft white powder of nanoparticles was prepared. The mean size of loaded nanoparticles was < 400 nm and zeta potential was negative. Spherical nanoparticles were observed by scanning electron microscopy. Encapsulation efficiency was around 80% and a strong interaction between the polymer and the drug was confirmed by differential scanning calorimetric analysis. In vitro drug release studies suggested a controlled and pulsatile release profile. System efficacy tests suggested similar results between the loaded nanoparticles and the nonencapsulated drug against the most common bacteria associated with acne. Cytotoxicity of AzA-loaded nanoparticles was concentration dependent, although not pronounced. The occluded patch test seemed to indicate that the formulation excipients were safe and thus AzA-loaded nanoparticles appear to be an efficient and safe treatment for acne.

Protective effects of azelaic acid against high-fat diet-induced oxidative stress in liver, kidney and heart of C57BL/6J mice

Excess fat intake induces hyperinsulinaemia, increases nutrient uptake and lipid accumulation, amplifies ROS generation, establishes oxidative stress and morphological changes leading to tissue injury in the liver, kidney and heart of high-fat diet (HFD)-fed mice. The effect of azelaic acid (AzA), a C9 α,ω-dicarboxylic acid, against HFD-induced oxidative stress was investigated by assaying the activities and levels of antioxidants and oxidative stress markers in the liver, kidney and heart of C57BL/6J mice. Mice were segregated into two groups, one fed standard diet (NC) and the other fed high-fat diet (HFD) for 15 weeks. HFD-fed mice were subjected to intragastric administration of AzA (80 mg/kg BW)/RSG (10 mg/kg BW) during 11-15 weeks. Glucose, insulin, triglycerides, hepatic and nephritic markers were analysed in the plasma and the activity of enzymatic, non-enzymatic antioxidants and lipid peroxidation markers were examined in the plasma/erythrocytes, liver, kidney and heart of normal and experimental mice. We inferred significant decrease in enzymatic and non-enzymatic antioxidants along with significant increase in glucose, insulin, hepatic and nephritic markers, triglycerides and lipid peroxidation markers in HFD-fed mice. Administration of AzA could positively restore the levels of plasma glucose, insulin, triglycerides, hepatic and nephritic markers to near normal. AzA increased the levels of enzymatic and nonenzymatic antioxidants with significant reduction in the levels of lipid peroxidation markers. Histopathological examination of liver, kidney and heart substantiated these results. Hence, we put forward that AzA could counteract the potential injurious effects of HFD-induced oxidative stress in C57BL/6J mice.

Elastic Polyesters from Glycerol and Azelaic Acid

Elastic polyester from glycerol and azelaic acid with different molar ratio was synthesized by simple catalyst-free esterification reaction. The ratio of azelaic acid to glycerol used in this experiment was 1:2, 1:1 and 2:1. The polyester with ratio 1:2 and 1:1 appear as clear, bubble free, non tacky and flexible after 48 hours at 125°C while the polyester with the ratio of 2:1 was cured after extension of 60 hours. The formation of ester bonds of the polyester produced is detected on the monomer molecular ratio and also on the efficiency of water removal during esterification process.

Phenolic and short-chained aliphatic organic acid constituents of wild oat (Avena fatua L.) seeds

The objective of this research was to identify and quantify the phenolic and short-chained aliphatic organic acids present in the seeds of three wild-type populations of wild oat and compare these results to the chemical composition of seeds from two commonly utilized wild oat isolines (M73 and SH430). Phenolic acids have been shown to serve as germination inhibitors, as well as protection for seeds from biotic and abiotic stress factors in other species, whereas aliphatic organic acids have been linked to germination traits and protection against pathogens. Wild oat populations were grown under a "common garden" environment to remove maternal variation, and the resulting seeds were extracted to remove the readily soluble and chemically bound phenolic and aliphatic organic acid components. Compounds were identified and quantified using gas chromatography-mass spectrometry. Ferulic and p-coumaric acid comprised 99% of the total phenolic acids present in the seeds, of which 91% were contained in the hulls and 98% were in the chemically bound forms. Smaller quantities of OH benzoic and vanillic acid were also detected. Soluble organic acids concentrations were higher in the M73 isoline compared to SH430, suggesting that these chemical constituents could be related to seed dormancy. Malic, succinic, fumaric and azelaic acid were the dominant aliphatic organic acids detected in all seed and chemical fractions.

Safety assessment of azelaic acid and its derivatives entrapped in nanovesicles

The aim of this study was to determine the safety of azelaic acid (AA) and its derivatives in nanovesicles for pharmaceutical and cosmetic uses. The hydrophilic property of AA was modified by complexing AA with hydroxypropyl-β-cyclodextrin (AACD). The lipophilic property of AA was improved to diethyl azelate (DA) by esterification with Fischer reaction. AA, AACD and DA were entrapped in liposomes and niosomes with the compositions of L-α-dipalmitoyl phosphatidylcholine/cholesterol = 7:3 and Tween 61/cholesterol = 1:1, respectively, by chloroform film method with sonication. The size of the vesicles ranged from 50 to 200 nm, indicating nanosize characteristics. The cytotoxicity of AA, AACD and DA entrapped nanovesicular formulations on mouse epidermal cell lines (JB6, normal cell lines) by the sulforhodamine B assay was modest when compared with cisplatin. Blank liposomes and niosomes gave no growth inhibitory effect. The irritation of AA, AACD and DA entrapped and not entrapped in nanovesicles on rabbit skin was examined according to the Environmental Protection Agency health effect test guidelines. The results showed no signs of erythema or edema within 72 h. AA and its derivatives were safe for topical use when entrapped in nanovesicles because of no toxicity to normal cell lines and no allergy on rabbit skin.

Characteristics and anti-proliferative activity of azelaic acid and its derivatives entrapped in bilayer vesicles in cancer cell lines

The hydrophilicity and lipophilicity of azelaic acid (AA) were modified to diethyl azelate (DA) which was synthesized by Fisher esterification reaction and identified by IR, MS and (1)H NMR and to azelaic acid-beta-cyclodextrin complex (AACD) which was prepared by inclusion complexation and identified by IR, DSC and XRD respectively. AA, DA and AACD were entrapped in liposomes and niosomes comprising of L-alpha-dipalmitoyl phosphatidylcholine (DPPC)/cholesterol at 7:3 molar ratio and Tween61/cholesterol at 1:1 molar ratio, respectively, using a thin-film hydration method with sonication. The size and morphology of these bilayer vesicles were determined by optical and transmission electron microscopy. The particle size was found to be in the range of 90-190 nm. The entrapment efficiency of AA, DA and AACD in all vesicular formulations was more than 80%, as analyzed by HPLC for AA and AACD, and GC for DA. Anti-proliferative activity of AA and its derivatives (DA and AACD) both entrapped and not entrapped in bilayer vesicles, using MTT assay in three cancer cell lines (HeLa, KB and B(16)F(10)) comparing with vincristine, were investigated. AACD showed the highest potency comparing to AA in HeLa, KB and B(16)F(10) of 1.48, 1.6 and 1.5 times, respectively. AA entrapped in liposomes was about 90 times more potent than the free AA, and about 1.5 times less potent than vincristine. When entrapped in bilayer vesicles, DA and AACD were more effective than AA in killing cancer cells. AACD entrapped in liposomes gave the highest anti-proliferation activity in HeLa cell lines with the IC(50) of 2.3 and 327 times more potent than vincristine and AA, respectively. DA in liposomes demonstrated the IC(50) of 0.03 times less potent than vincristine in KB cell lines, while in B(16)F(10) AACD in niosomes showed the IC(50) of 0.05 times less potent than vincristine. This study has suggested that the modification of AA by derivatization and complexation as well as the entrapment in bilayer vesicles can enhance its therapeutic efficacy.