Development and validation of a simultaneous analytical method for non-steroidal therapeutic compounds in cosmetics using liquid chromatography-tandem mass spectrometry.

Atopic dermatitis is a typical chronic inflammatory skin disease that affects all age groups and requires basic skin care for treatment. Anti-inflammatory and antiallergy steroids are the most frequently used treatments but they are limited due to their side effects caused by a weakening of the immune system. Many consumers focus on performance as a criterion for selecting cosmetics. However, steroids have been illegally used to improve the performance of cosmetics, and consumers have been adversely affected by the corresponding side effects. In this paper, we propose a simple and rapid method using liquid chromatography-tandem mass spectrometry to simultaneously analyze ten non-permitted atopic therapeutic compounds in cosmetic products: chlorpheniramine maleate, ketotifen fumarate, doxepin hydrochloride, azelastine hydrochloride, bufexamac, clotrimazole, tranilast, fusidic acid, tacrolimus, and pimecrolimus. Additionally, the major characteristic fragment ions for tacrolimus, pimecrolimus, and clotrimazole were identified by time-of-flight mass spectrometry. The specificity, linearity, limit of detection, limit of quantification, recovery, precision, accuracy, and stability of the proposed method were validated. The limit of detection and quantification were in the ranges of 5.05-203.30 pg/mL and 15.15-609.90 pg/mL, respectively. The proposed analysis method could help improve the safety management of cosmetics.

HDAC6 Is Involved in the Histone Deacetylation of In Vitro Maturation Oocytes and the Reprogramming of Nuclear Transplantation in Pig.

It remained unknown whether HDAC6 affected the histone deacetylation of in vitro maturation oocytes and the reprogramming of nuclear transplantation in pig. Our results indicated that HDAC6 specific inhibition did not affect overall HDAC activity and meiosis process, which increased histone H3K9/K14 and H4K8 acetylation of porcine in vitro maturation oocytes and pseudo-pronucleus embryos. HDAC6 inhibition also significantly enhanced the cleavage and blastocyst of nuclear transfer embryos (0.81 ± 0.12 vs. 0.68 ± 0.12 and 0.46 ± 0.19; 0.73 ± 0.13 vs. 0.63 ± 0.18 and 0.40 ± 0.16, P<0.05). The inhibition of HDAC6 significantly enhanced histone H3K9/K14 and H4K8 acetylation, and upregulated the OCT4 and CDX2 expressions (1.83 ± 0.16 vs. 1.00 ± 0.00 %; 2.07 ± 0.09 vs. 1.00 ± 0.00; P<0.05) in porcine SCNT blastocysts. Interestingly, HDAC6 inhibition significantly increased the pseudo-pronucleus volume during somatic cell reprogramming. Thus, HDAC6 was required for porcine histone deacetylation during the in vitro maturation and pseudo-pronucleus stages. HDAC6 inhibition improved the in vitro development of nuclear transfer embryos. HDAC6 may restrict the reprogramming of somatic nuclear transfer by regulating pseudo-pronucleus expansion. We need further research to confirm this in the future.

Severe cutaneous eruptions following the topical use of preparations containing bufexamac: Is it time to reconsider its registration in Australia?

Despite being a well-recognised cause of allergic contact dermatitis with an embargo in many countries around the world, bufexamac is available over the counter in topical preparations in Australia. We present a series of patients who developed severe cutaneous eruptions after the topical application of bufexamac containing preparations to highlight the potential risks of this medication, as well as advocate for the reconsideration of its registration by the Therapeutic Goods Administration in Australia.

Carbamates as Potential Prodrugs and a New Warhead for HDAC Inhibition.

We designed and synthesized carbamates of the clinically-approved HDAC (histone deacetylase) inhibitor vorinostat (suberoylanilide hydroxamic acid, SAHA) in order to validate our previously-proposed hypothesis that these carbamates might serve as prodrugs for hydroxamic acid containing HDAC inhibitors. Biochemical assays proved our new compounds to be potent inhibitors of histone deacetylases in vitro, and they also showed antiproliferative effects in leukemic cells. These results, as well as stability analysis led to the suggestion that the intact carbamates are inhibitors of histone deacetylases themselves, representing a new zinc-binding warhead in HDAC inhibitor design. This suggestion was further supported by the synthesis and evaluation of a carbamate derivative of the HDAC6-selective inhibitor bufexamac.

Regulation of Retinoic Acid Inducible Gene-I (RIG-I) Activation by the Histone Deacetylase 6.

Retinoic acid inducible gene-I (RIG-I) is a cytosolic pathogen recognition receptor that initiates the immune response against many RNA viruses. Upon RNA ligand binding, RIG-I undergoes a conformational change facilitating its homo-oligomerization and activation that results in its translocation from the cytosol to intracellular membranes to bind its signaling adaptor protein, mitochondrial antiviral-signaling protein (MAVS). Here we show that RIG-I activation is regulated by reversible acetylation. Acetyl-mimetic mutants of RIG-I do not form virus-induced homo-oligomers, revealing that acetyl-lysine residues of the RIG-I repressor domain prevent assembly to active homo-oligomers. During acute infection, deacetylation of RIG-I promotes its oligomerization upon ligand binding. We identify histone deacetylase 6 (HDAC6) as the deacetylase that promotes RIG-I activation and innate antiviral immunity to recognize and restrict RNA virus infection.

Bufexamac ameliorates LPS-induced acute lung injury in mice by targeting LTA4H.

Neutrophils play an important role in the occurrence and development of acute lung injury (ALI). Leukotriene B4 (LTB4), a hydrolysis product of epoxide leukotriene A4 (LTA4) catalyzed by LTA4 hydrolase (LTA4H), is one of the most potent chemoattractants for neutrophil. Bufexamac is a drug widely used as an anti-inflammatory agent on the skin, however, the mechanism of action is still not fully understood. In this study, we found bufexamac was capable of specifically inhibiting LTA4H enzymatic activity and revealed the mode of interaction of bufexamac and LTA4H using X-ray crystallography. Moreover, bufexamac significantly prevented the production of LTB4 in neutrophil and inhibited the fMLP-induced neutrophil migration through inhibition of LTA4H. Finally, bufexamac significantly attenuated lung inflammation as reflected by reduced LTB4 levels and weakened neutrophil infiltration in bronchoalveolar lavage fluid from a lipopolysaccharide-induced ALI mouse model. In summary, our study indicates that bufexamac acts as an inhibitor of LTB4 biosynthesis and may have potential clinical applications for the treatment of ALI.

Contact sensitization in patients with suspected cosmetic intolerance: results of the IVDK 2006-2011.

BACKGROUND: Ingredients of leave-on cosmetics and body care products may sensitize. However, not every case of cosmetic intolerance is due to contact sensitization. OBJECTIVE: To describe the frequency of contact sensitization due to cosmetics in a large clinic population, and a possible particular allergen pattern. METHODS: Retrospective analysis of data from the Information Network of Departments of Dermatology, 2006-2011. RESULTS: Of 69 487 patients tested, 'cosmetics, creams, sunscreens' was the only suspected allergen source category in 10 124 patients (14.6%). A final diagnosis 'allergic contact dermatitis' was stated in 2658 of these patients (26.3%).Compared to a control group, there were significantly more reactions to fragrance mixes I and II, balsam of Peru, methylchloroisothiazolinone/methylisothiazolinone (MCI/MI) and lanolin alcohols. No special pattern of fragrance sensitization could be identified. Among the preservatives, MI was by far the leading allergen, while sensitization to other widely used compounds like parabens or phenoxyethanol was rare. CONCLUSIONS: True allergic reactions to cosmetic ingredients are rarer than generally assumed. Limitation of exposure to MI in leave-on cosmetics and body care products is urgently needed.

Allergic contact dermatitis to topical preparations of bufexamac.

In Australia bufexamac is mainly used for pharmacist-initiated local treatment of various dermatoses. The European Medicines Agency's Committee for Medicinal Products for Human Use recently recommended that marketing authorisation for bufexamac-containing preparations be revoked throughout the European Union because of the risk of severe allergic contact dermatitis. We retrospectively reviewed the patch test database at the Skin and Cancer Foundation Inc. and identified 19 cases of positive reactions to bufexamac (5% petrolatum) from 451 people patch tested. The bufexamac reaction was deemed relevant to the presenting dermatitis in 13 of 19 (68%) patients. Bufexamac allergic contact dermatitis is under-reported in the English literature. We wish to emphasise the severity and the unusually polymorphic eruptions observed in some of the cases. Clinicians should consider the possibility of allergic contact dermatitis to bufexamac-containing preparations in all patients where there is a history of exposure, even if used for only a short time.

In vitro photobiochemical characterization of sulfobutylether-ß-cyclodextrin formulation of bufexamac.

The present study aimed to modulate the photoreactivity of bufexamac, with a focus on photostability and phototoxicity, by forming an inclusion complex with sulfobutylether-ß-cyclodextrin (SBECD). The photobiochemical properties of bufexamac were evaluated by reactive oxygen species (ROS) assay and using in vitro photogenotoxic assessment tools. To assess the inclusion properties of SBECD complex with bufexamac, a UV absorption spectroscopic study was also carried out. The influence of SBECD on the photoreactivity of bufexamac was analyzed by ROS assay and photostability test. From the photobiochemical data, superoxide generation from irradiated bufexamac indicated its photoreactivity; however, the photogenotoxic risk of bufexamac was negligible owing to low DNA-binding affinity and DNA-photocleaving activity. SBECD complex of bufexamac was formed, and the association constant of the complex was calculated to be 620M(-1). On the basis of the photochemical data on bufexamac co-existing with SBECD, ROS generation from irradiated bufexamac (200µM) was inhibited by SBECD at concentrations of over 20µM. The degradation constant of bufexamac in SBECD was decreased ca. 30% compared with that of bufexamac, suggesting improvement of its photostability. The phototoxic risk of bufexamac might be attenuated by SBECD complexation, and cyclodextrin inclusion complexes might be a useful approach for modulating the phototoxicity of drugs.

[Bufexamac-induced pigmented purpuric eruption]. / Kontaktallergie durch Bufexamac unter dem Bild einer chronischen Pigmentpurpura.

We report on a case of a bufexamac-induced allergic contact dermatitis with hematogenous dissemination presenting with the clinical and histological picture of a pigmented purpuric eruption. To our knowledge this is the first report on a bufexamac-induced pigmented purpuric dermatosis. It represents a further example of the clinical variety of cutaneous side-effects caused by bufexamac.

A systematic review of randomized controlled trials of treatments for inherited forms of epidermolysis bullosa.

BACKGROUND: Many interventions have been described for inherited epidermolysis bullosa (EB), but it is unclear which are beneficial. AIMS: A systematic review of randomized controlled trials (RCTs) was performed to inform practice and highlight research gaps. METHODS: The Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE and the Cochrane Skin Group specialist library, from inception until 1 April 2007, were searched. Primary outcomes were healing of lesions or prevention of new lesions. Trials were assessed for quality of reporting and data were extracted. RESULTS: Five randomized double-blind placebo-controlled crossover studies were identified (n = 102). Two studies assessed oral tetracyclines in EB simplex (EBS). In one study (n = 12), 4/6 patients improved and 2/6 deteriorated on a dose of 1500 mg of tetracycline daily; only two patients completed the study. In the second study (n = 21), 6/18 and 7/18 improved on oxytetracycline 1 g and placebo, respectively. Two RCTs assessed topical interventions for EBS: aluminium chloride hexahydrate solution 20% (n = 23) and bufexamac cream 5% (n = 8). Neither showed a benefit over placebo. One RCT of 36 patients with recessive dystrophic EB compared phenytoin with placebo and failed to show any difference in mean lesion counts (difference = 0, 95% CI -11 to 4). CONCLUSIONS: There is no reliable trial evidence for interventions in inherited EB. In future, it may be that gene treatment becomes the best treatment approach for these diseases.

Non-steroidal anti-inflammatory drugs selectively inhibit cytokine production by NK cells and gamma delta T cells.

Non-steroidal anti-inflammatory drugs (NSAIDs) are known to be risk factors for a systemic inflammatory syndrome in viral infections. Innate immune cells are likely to represent the preferential targets for the deleterious effects of NSAIDs in patients with viral infections. We therefore examined whether various classes of NSAIDs could selectively inhibit cytokine production by innate immune cells. NSAIDs selectively inhibited interferon (IFN)-gamma and tumor necrosis factor (TNF)-alpha production by natural killer (NK) and gammadelta T cells with each NSAID displaying its own unique pattern of inhibition, while sparing that by acquired immune cells. These inhibitions were independent on cyclooxygenase inhibition. These NSAIDs directly inhibited the cytokine production by the purified gammadelta T-cell population without involving other cell populations. The selective inhibition of the early generation of IFN-gamma and TNF-alpha from NK and gammadelta T cells by NSAIDs may serve to drive the subsequent acquired immune responses towards a Th2 phenotype, leading to the aggravation of allergic symptoms. Our results provide a mechanism to explain the deleterious effects of NSAIDs on clinical symptoms of viral infections and allergic diseases and suggest more targeted use depending on the type of disease.

Changes in MMP-2 and -9 activity and MMP-8 reactivity after amphotericin B induced synovitis and treatment with bufexamac.

The objective here was to evaluate the acute effects of induced arthritis on synovial fluid (SF) levels of matrix metalloproteinases (MMP) -2, -8 and -9 in horses. To evaluate MMP-2 and -9 activities and the effect of non-steroidal anti-inflammatory drug (NSAID) bufexamac during remission from acute arthritis. Aseptic arthritis was induced in 24 Standardbred horses using 20 mg of amphotericin B as a single intra-articular (IA) injection in the right intercarpal joint. After 1 week and 2 weeks, horses were treated intra-articularly with 10, 20, or 40 mg of bufexamac suspension or with sterile saline solution as control. SF was sampled prior to induction and at weekly intervals for 5 weeks. Fluids were evaluated for MMP-2 and MMP-9 activity by gelatin zymography or for MMP-8 immunoreactivity by Western Blotting. IA injection of amphotericin B consistently resulted in significant increase in the immunoreactivity of MMP-8 and activity of both the latent and the active forms of MMP-2 and -9, among which the active form of MMP-2 increased the most. MMP-9 levels declined to pre-induction levels within 2 weeks, whereas levels of MMP-2 remained still high after 5 weeks. Treatment with bufexamac did not significantly affect levels of gelatinolytic MMP. Results suggest that after acute arthritis of horses, elevated MMP activity is present in the joint, for several weeks, to a degree that could promote cartilage degradation, and treatment with the NSAID bufexamac is not likely to affect that. Furthermore, analysing levels of MMP-9 activity and especially levels of active forms of MMP-2 activity may be valuable to predict the time of occurrence of arthritis in horses.

Chronic urticaria due to Blastocystis hominis.

A 24-year-old woman had a 9-week history of second to third daily urticaria that began after an episode of contact urticaria to topical bufexamac. She was found to have an underlying gastrointestinal infection with Blastocystis hominis. This was thought to be clinically relevant as she had a history of mild chronic diarrhoea. After treatment of the Blastocystis hominis, her urticaria ceased. This could indicate the importance of performing stool microscopy and culture on all patients with chronic urticaria of unknown aetiology. The relationship of urticaria to intestinal parasites and the possibility that non-steroidal anti-inflammatory medications could act as cofactors that help precipitate an urticarial reaction is discussed.

[A common and insidious side-effect: allergic contact dermatitis caused by bufexamac used in the treatment of dermatitis. Results from the Information Network of Departments of Dermatology (IDVK)]. / Eine heimtückische und häufige Nebenwirkung: Kontaktallergien durch das Ekzemtherapeutikum Bufexamac. Ergebnisse des IVDK.

BACKGROUND AND OBJECTIVE: Bufexamac is a non-steroidal, anti-inflammatory drug used in the topical treatment of atopic dermatitis, stasis dermatitis and perianal eczema. The substance is known to cause severe allergic contact dermatitis (ACD) as an adverse effect (AE), which may be indistinguishable from the eczema which is to be treated. Hence the diagnosis of this AE is often considerably delayed. In order to estimate the quantitative importance of ACD to bufexamac, data of the Information Network of (German) Departments of Dermatology (IVDK) from July 1999 to December 2004 were analysed. PATIENTS AND METHODS: During the study period, 39,392 unselected patients from 40 German departments of the IVDK were patch tested with bufexamac (5 % pet). The results of the reading after 72 hours were analysed. The dichotomized patch test result was further assessed for possible risk factors from the patients' history and clinical diagnosis by Poisson regression analysis. RESULTS: In 560 of 39,392 patients contact allergy to bufexamac was diagnosed, i. e. 1.4 % (95 % confidence interval: 1.3 - 1.5), standardized for sex and age. The Poisson regression analysis revealed a significantly increased risk associated with the following factors: multiple sensitization, perianal eczema, underlying atopic dermatitis, leg dermatitis, female gender and residence in areas of Germany other than Eastern Germany. The latter observation can be explained by low prescription rates in Eastern Germany. CONCLUSION: Bufexamac is an important allergen. Extrapolating the frequency of 1.4 % in our data to the whole German population by the CE-DUR approach yields an estimate of about 6000 cases per year. In view of the high frequency of sensitization, the pitfalls in diagnosis, the severity of the course of disease and the lack of efficacy of this drug, the risk to benefit ratio is obviously critical.