Oxidative Stress in Cutaneous Lichen Planus-A Narrative Review

The role of skin microbiota in lichen planus from a Mendelian randomization perspective

Lichen planus is a chronic skin lesion characterized by pruritic violaceous papules, which has a high risk of morbidity. Skin microbiota plays an important role in the maintenance of cutaneous mucosal barrier and human health and immune homeostasis. Studies have shown that skin microbiota may play a role in the pathogenesis of lichen planus, but it is not yet clear. MR studies have been performed to determine causal associations. Lichen planus samples from Finn database were extracted from published GWAS data, including 6,411 cases and 405,770 controls; skin microbiota samples were gathered from a meta-analysis of German population-based GWAS, which included 1,656 skin samples from two cohorts: KORA FF4 (n = 353) and PopGen (n = 294), comprising 4,685,714 SNPs. The IVW method was used as the main statistical method, supplemented by three methods: MR-Egger, weighted median and weighted mode. FDR correction and MR Steiger test were used to reduce false positives. IVW method revealed a negative correlation between Burkholderia in the moist anterior elbow and lichen planus (OR: 0.934, 95% CI: 0.910-0.986, P = 0.017). These associations remained stable following false discovery rate correction (P < 1e-5). Our study highlights a possible causal role of Burkholderia in the development of lichen planus and suggests that Burkholderia may reduce the occurrence of lichen planus by affecting macrophages.

Lichen Planus: What is New in Diagnosis and Treatment?

Lichen planus (LP), an idiopathic, multifaceted chronic inflammatory disease with a heterogeneous clinical presentation, affects approximately 0.5-1% of the population. The various clinical manifestations of LP fall into three broad categories, namely cutaneous, appendageal, and mucosal, with further subclassification depending on the morphology and distribution patterns of individual lesions. There is mounting evidence that LP has systemic associations, including autoimmune conditions, glucose intolerance, dyslipidemia, and cardiovascular disorders. Cutaneous hypertrophic and mucosal forms of LP are at a heightened risk for malignant transformation. Familiarity with these potential associations in conjunction with long-term follow-up and regular screening could lead to a timely diagnosis and management of concomitant conditions. In addition, the frequent quality of life (QoL) impairment in LP underscores the need for a comprehensive approach including psychological evaluation and support. Several treatment strategies have been attempted, though most of them have not been adopted in clinical practice because of suboptimal benefit-to-risk ratios or lack of evidence. More recent studies toward pathogenesis-driven treatments have identified Janus kinase inhibitors such as tofacitinib, phosphodiesterase-4 inhibitors such as apremilast, and biologics targeting the interleukin-23/interleukin-17 pathway as novel therapeutic options, resulting in a dramatic change of the treatment landscape of LP. This contemporary review focuses on the diagnosis and management of LP, and places emphasis on more recently described targeted treatment options.

Lichen planus after COVID-19 infection and vaccination

BACKGROUND

Lichen planus is one of the common adverse reactions after COVID-19 infection and vaccination. Despite it being reported in several case reports, the literature including a large sample of the studied population is lacking. The current study was performed to assess the risk of LP after COVID-19 infection as well as COVID-19 vaccination.

METHODS

The current study was designed as a retrospective cross-sectional hospital-based study of registered patients at the University of Florida (UF) health centers. The diagnoses of LP, COVID-19 infection, and COVID-19 vaccines were detected. The logistic regression model was used to assess the risk of developing LP after COVID-19 infection and vaccination.

RESULTS

A total hospital patient of 684,110 attended UF Health centers were included in this study. 181 patients reported LP after COVID-19 vaccination and 24 patients developed LP after COVID-19 infection. The risk of developing LP after COVID-19 vaccination was 1.573 while the risk of developing LP after COVID-19 infection was 1.143.

CONCLUSION

The odds of getting LP after COVID-19 vaccination are significantly developed. The current study showed that COVID-19 infection and vaccination are associated with LP. So, healthcare practitioners should be aware of this reaction for rapid recognition and treatment.

Structural Control Enables Catalytic and Electrocatalytic Activity of Porous Tetrametallic Nanorods

Integrating more than one type of metal into a nanoparticle that has a well-defined morphology and composition expands the functionalities of nanocatalysts. For a metal core/porous multimetallic shell nanoparticle, the availability of catalytically active surface sites and molecular mass transport can be enhanced, and the multielemental synergy can facilitate intraparticle charge transport. In this work, a reliable and robust synthesis of such a functional tetrametallic nanoparticle type is presented, where a micro- and mesoporous PdPtIr shell is grown on Au nanorods. The effect of critical synthesis parameters, namely temperature and the addition of HCl are investigated on the hydrodynamic size of the micellar pore template as well as on the stability of the metal chloride complexes and various elemental analysis techniques prove composition of the porous multimetallic shell. Due to the synergistic properties, the tetrametallic nanorods possess extensive negative surface charge making them a promising catalyst in reduction reactions. Dye degradation as well as the conversion of p-nitrophenol to p-aminophenol is catalyzed by the supportless nanorods without light illumination. By depositing the particles onto conductive substrates, the nanostructured electrodes show promising electrocatalytic activity in ethanol oxidation reaction. The nanocatalyst presents excellent morphological stability during all the catalytic test reactions.

Salivary Levels of Malondialdehyde and Total Antioxidant Capacity Following Third Molar Surgery - An Evaluative Study

Introduction

Impacted and semi-impacted third molar surgery can lead to considerable distress and discomfort in patients.

Aims

The present study aimed to assess the changes in salivary levels of malondialdehyde (MDA) and total antioxidant capacity (TAC) after third molar surgery.

Materials and Methods

In this study, 210 patients scheduled for third molar surgery were selected. Unstimulated whole saliva samples were collected from patients preoperatively and one week after the surgery, via the 'spitting method'. The collected samples were immediately centrifuged and the supernatants were stored at -20°C until testing. The levels of MDA and TAC were measured with a spectrophotometer.

Results

The results were presented as mean ± standard deviation and paired t-test was used to statistically analyse the changes in pre-operative and post-operative values of MDA and TAC. A decrease of mean salivary TAC (P = 0.031) and an increase of mean salivary MDA (P = 0.034) were detected postoperatively.

Discussion

Following third molar surgery, the increase of mean salivary MDA and the decrease of mean salivary TAC were detected; however, these changes were not statistically significant.

The Interplay between Nitrosative Stress, Inflammation, and Antioxidant Defense in Patients with Lichen Planus

BACKGROUND

Lichen planus (LP) is a chronic inflammatory skin disease of unelucidated etiology. LP immunopathogenesis is mainly governed by cytotoxic T lymphocytes that mediate an immune response in basal keratinocytes, which may transform into a reservoir of antigens able to initiate an autoimmune reaction. However, other pathogenic pathways complement these mechanisms. Recent studies highlight the involvement of nitrosative stress in the pathogenesis of chronic inflammatory skin diseases. Current data on its role in the pathogenesis of LP are scarce.

METHODS

In this article, we investigated nitrosative stress in 40 cutaneous LP (CLP) patients compared to 40 healthy subjects using serum markers including nitrosative stress markers-direct nitrite, total nitrite, nitrate and symmetric dimethylarginine (SDMA), total antioxidant status (TAS), and hsCRP, a marker of inflammation, and analyzed the relationship between nitrosative stress, antioxidant defense, and inflammation to offer new insights into the role of the NO pathway in LP pathogenesis.

RESULTS

We identified significantly higher serum levels of direct nitrite, total nitrite, nitrate, SDMA and hsCRP, and significantly lower levels of TAS in CLP patients versus controls. There were significant negative correlations between the serum levels of TAS and significantl positive correlations between the serum levels of hsCRP and the analyzed nitrosative stress markers in patients with CLP.

CONCLUSION

Our results indicate an increased level of nitrosative stress in LP patients that correlates with a pro-inflammatory status and altered antioxidant defense.

Extracellular vesicles derived from mesenchymal stem cells: the wine in Hebe's hands to treat skin aging

Owing to its constant exposure to the external environment and various stimuli, skin ranks among the organs most vulnerable to manifestations of aging. Preventing and delaying skin aging has become one of the prominent research subjects in recent years. Mesenchymal stem cells (MSCs) are multipotent stem cells derived from mesoderm with high self-renewal ability and multilineage differentiation potential. MSC-derived extracellular vesicles (MSC-EVs) are nanoscale biological vesicles that facilitate intercellular communication and regulate biological behavior. Recent studies have shown that MSC-EVs have potential applications in anti-aging therapy due to their anti-inflammatory, anti-oxidative stress, and wound healing promoting abilities. This review presents the latest progress of MSC-EVs in delaying skin aging. It mainly includes the MSC-EVs promoting the proliferation and migration of keratinocytes and fibroblasts, reducing the expression of matrix metalloproteinases, resisting oxidative stress, and regulating inflammation. We then briefly discuss the recently discovered treatment methods of MSC-EVs in the field of skin anti-aging. Moreover, the advantages and limitations of EV-based treatments are also presented.

Prevalence of oral lichen planus in patients with diabetes mellitus: A cross-sectional study

OBJECTIVES

Oral lichen planus, a chronic inflammatory immune disease, occurs in the oral mucosa. We aimed to assess the prevalence and possible influencing factors of oral lichen planus in patients with diabetes mellitus.

SUBJECTS AND METHODS

This cross-sectional study involved 525 patients with diabetes mellitus and 525 controls. We collected information on blood glucose level, duration of diabetes, diabetic complications, treatment methods, other systemic diseases and medication history.

RESULTS

Oral lichen planus was significantly more prevalent in the diabetes mellitus/type 2 diabetes mellitus group than in the controls (2.3%/2.2% vs. 0.6%, p = 0.019/0.022). There was no significant association between patients with diabetes mellitus with and those without oral lichen planus in age (p = 0.195), sex (p = 0.390), blood glucose level (p = 1), duration of diabetes (p = 0.638), diabetic complications (p = 1), treatment methods (p = 0.962), other systemic diseases (p = 0.891) and medication history (p = 0.848).

CONCLUSIONS

Diabetes mellitus was associated with oral lichen planus; there was a higher prevalence of oral lichen planus in patients with diabetes mellitus/type 2 diabetes mellitus than in those without diabetes. Oral lichen planus development in patients with diabetes mellitus was not significantly associated with age, sex, blood glucose level, duration of diabetes, diabetic complications, treatment methods, other systemic diseases and medication history.

A Panel of Potential Serum Markers Related to Angiogenesis, Antioxidant Defense and Hypoxia for Differentiating Cutaneous Squamous Cell Carcinomas from Actinic Keratoses

Cutaneous squamous cell carcinoma (cSCC) arising from the malignant proliferation of epidermal keratinocytes is the second most common skin cancer. Actinic keratosis (AK), which is considered cSCC in situ, may progress into invasive tumors. Currently, there are no serum markers that can differentiate cSCC from AK. The aim of our study was to assess angiogenesis and oxidative stress in patients with cSCC and patients with AK and find reliable serum markers useful in the diagnosis of cSCC. We have determined the serum levels of a group of proangiogenic factors (MMP-2, MMP-9, VEGF, FGF2), the total antioxidative status/capacity (TAS/TAC), ImAnOx, a marker of oxidative stress, and HIF-1 alpha, an indicator of hypoxia. We have identified higher serum levels of MMP-2. MMP-9, VEGF, FGF2 and HIF-1 alpha and lower levels of ImAnOx in cSCC patients compared to AK patients and controls. There were no statistically significant differences between AK patients and controls. We have found positive correlations between proangiogenic markers and HIF-1 alpha and negative correlations between proangiogenic markers and ImAnOx. Our results suggest that MMP-2, MMP-9, VEGF, FGF2, ImAnOx and HIF-1 may be promising markers for differentiating AK from cSCC, and there is a link between angiogenesis, oxidative stress and hypoxia.

Markers of Oxidative Stress in Patients with Acne: A Literature Review

Acne vulgaris is a chronic inflammatory skin disease of the pilosebaceous unit. Its pathogenesis is multifactorial and involves the overlap between four main processes: alteration of the keratinization, increased sebum production, colonization with Cutibacterium acnes, and inflammation. The role of oxidative stress (OS) has been intensively studied in inflammatory skin conditions such as psoriasis, vitiligo, or atopic dermatitis. However, the involvement of OS in the pathogenesis of acne is less known. The evidence accumulated over the last decade suggests that in the case of acne patients, there is an imbalance between oxidants and antioxidants. In this review, we analyzed studies that evaluated markers of OS in patients with acne, published in the last ten years, with the aim of providing new insights into the pathogenesis of acne.

Comprehensive Insight into Lichen Planus Immunopathogenesis

Lichen planus is a chronic disease affecting the skin, appendages, and mucous membranes. A cutaneous lichen planus is a rare disease occurring in less than 1% of the general population, while oral illness is up to five times more prevalent; still, both forms equally impair the patient's quality of life. The etiology of lichen planus is not entirely understood. Yet, immune-mediated mechanisms have been recognized since environmental factors such as hepatitis virus infection, mechanical trauma, psychological stress, or microbiome changes can trigger the disease in genetically susceptible individuals. According to current understanding, lichen planus immunopathogenesis is caused by cell-mediated cytotoxicity, particularly cytotoxic T lymphocytes, whose activity is further influenced by Th1 and IL-23/Th-17 axis. However, other immunocytes and inflammatory pathways complement these mechanisms. This paper presents a comprehensive insight into the actual knowledge about lichen planus, with the causal genetic and environmental factors being discussed, the immunopathogenesis described, and the principal effectors of its inflammatory circuits identified.

Oxidative Stress and Phototherapy in Atopic Dermatitis: Mechanisms, Role, and Future Perspectives

Atopic dermatitis is a chronic inflammatory skin disease in which the overproduction of reactive oxygen species plays a pivotal role in the pathogenesis and persistence of inflammatory lesions. Phototherapy represents one of the most used therapeutic options, with benefits in the clinical picture. Studies have demonstrated the immunomodulatory effect of phototherapy and its role in reducing molecule hallmarks of oxidative stress. In this review, we report the data present in literature dealing with the main signaling molecular pathways involved in oxidative stress after phototherapy to target atopic dermatitis-affected cells. Since oxidative stress plays a pivotal role in the pathogenesis of atopic dermatitis and its flare-up, new research lines could be opened to study new drugs that act on this mechanism, perhaps in concert with phototherapy.

Bilirubin as a new antioxidant in melasma

BACKGROUND

Oxidative stress and its role in the pathogenesis of cutaneous diseases have been widely investigated. However, there are few studies that have solely assessed the contribution of intracellular antioxidants in the etiopathology of melasma. Furthermore, there are convincing reports about antioxidant properties of bilirubin (Bil) and uric acid (UA) in some skin disorders but not melasma.

OBJECTIVE

This study aimed to determine serum levels of two major extracellular antioxidants (Bil and UA) levels in patients with melasma and their correlation with the severity and extent of the disease.

METHODS

In this case-control study, the serum levels of bilirubin and uric acid of 50 melasma patients were compared with 50 healthy controls. Moreover, the correlation of serum concentrations of these antioxidants with the extent and severity of the disease were assessed.

RESULTS

The serum concentration of Bil was significantly higher in the case group (p < 0.05). Furthermore, serum Bil level had a positive correlation with the extent of the melasma (correlation coefficient, +0.3; p < 0.05). No significant difference was found between the serum concentrations of UA between the study and control group. Neither Bil nor UA had a significant correlation with the severity of the disease.

CONCLUSION

Oxidative stress may play a major role in the etiopathology of melasma and bilirubin, as an antioxidant, could be involved in the process of oxidative stress.

Ischemia-Modified Albumin—A Potential New Marker of Oxidative Stress in Dermatological Diseases

There is growing evidence that oxidative stress is involved in the pathogenesis of numerous conditions, including dermatological diseases. Various markers are available to assess oxidative stress, but none of these can be considered the ideal marker. Recent studies have shown that ischemia-modified albumin (IMA) is not only an indicator of ischemia, but also a marker of oxidative stress. We have conducted a narrative review to evaluate the role of IMA in dermatological diseases. We have identified 24 original articles that evaluated IMA in skin disorders (psoriasis, acne vulgaris, hidradenitis suppurativa, urticaria, vitiligo and Behcet’s disease) and hair disorders (alopecia areata, androgenetic alopecia and telogen effluvium). The results of the studies analyzed reveal that IMA may be considered a new marker of oxidative stress in dermatological diseases and offer new insights into the pathogenesis of these disorders and the theoretical basis for the development of new, effective, targeted therapies. To the best of our knowledge, this is the first review that gathers up data on the role of IMA in dermatological diseases.

Assessing the Oxidative State of the Skin by Combining Classical Tape Stripping with ORAC Assay

The antioxidant barrier system of the skin acts as the main defence against environmental pro-oxidants. Impaired skin oxidative state is linked to unhealthy conditions such as skin autoimmune diseases and cancer. Thus, the evaluation of the overall oxidative state of the skin plays a key role in further understanding and prevention of these disorders. This study aims to present a novel ex vivo model to evaluate the skin oxidative state by the measurement of its antioxidant capacity (AOC). For this the ORAC assay was combined with classical tape stripping and infrared densitometry to evaluate the oxidative state of the stratum corneum (SC). Outcomes implied the suitability of the used model to determine the intrinsic antioxidant capacity (iAOC) of the skin. The average iAOC of untreated skin was determined as 140 ± 7.4 µM TE. Skin exposure to UV light for 1 h reduced the iAOC by about 17%, and exposure for 2 h decreased the iAOC by about 30%. Treatment with ascorbic acid (AA) increased the iAOC in a dose-dependent manner and reached an almost two-fold iAOC when 20% AA solution was applied on the skin. The application of coenzyme Q10 resulted in an increase in the iAOC at low doses but decreased the iAOC when doses > 1% were applied on the skin. The results show that the combination of classical tape stripping and ORAC assay is a cost-effective and versatile method to evaluate the skin oxidative state and the pro-oxidate and antioxidative effects of topical skin treatments on the iAOC of the skin. Therefore, the model can be considered to be a valuable tool in skin research.

Modulating the Antioxidant Response for Better Oxidative Stress-Inducing Therapies: How to Take Advantage of Two Sides of the Same Medal?

Oxidative stress-inducing therapies are characterized as a specific treatment that involves the production of reactive oxygen and nitrogen species (RONS) by external or internal sources. To protect cells against oxidative stress, cells have evolved a strong antioxidant defense system to either prevent RONS formation or scavenge them. The maintenance of the redox balance ensures signal transduction, development, cell proliferation, regulation of the mechanisms of cell death, among others. Oxidative stress can beneficially be used to treat several diseases such as neurodegenerative disorders, heart disease, cancer, and other diseases by regulating the antioxidant system. Understanding the mechanisms of various endogenous antioxidant systems can increase the therapeutic efficacy of oxidative stress-based therapies, leading to clinical success in medical treatment. This review deals with the recent novel findings of various cellular endogenous antioxidant responses behind oxidative stress, highlighting their implication in various human diseases, such as ulcers, skin pathologies, oncology, and viral infections such as SARS-CoV-2.

Lichen planus flare following COVID-19 vaccination: A case report

We report the third case of cutaneous lichen planus (LP) following COVID-19 BNT162b2 vaccination in a 59-year-old woman with previous LP. The reactivation of LP in patients with dormant LP suggests a possible vaccine-induced immune dysregulation. We suggest that the already described vaccine-induced upregulation of Th1 response may play a relevant role in LP reactivation, through an increase in inflammatory cytokines involved in the pathogenesis of LP. Interestingly, LP has already been associated with vaccinations and viral infections including COVID-19 disease. However, the exact mechanism underlying LP (re)activation after Pfizer-BiotNtech COVID-19 vaccination is still widely unknown and needs to be further investigated.

What Are Reactive Oxygen Species, Free Radicals, and Oxidative Stress in Skin Diseases?

Oxygen in the atmosphere is a crucial component for life-sustaining aerobic respiration in humans. Approximately 95% of oxygen is consumed as energy and ultimately becomes water; however, the remaining 5% produces metabolites called activated oxygen or reactive oxygen species (ROS), which are extremely reactive. Skin, the largest organ in the human body, is exposed to air pollutants, including diesel exhaust fumes, ultraviolet rays, food, xenobiotics, drugs, and cosmetics, which promote the production of ROS. ROS exacerbate skin aging and inflammation, but also function as regulators of homeostasis in the human body, including epidermal keratinocyte proliferation. Although ROS have been implicated in various skin diseases, the underlying mechanisms have not yet been elucidated. Current knowledge on ROS-related and oxidative stress-related skin diseases from basic research to clinical treatment strategies are discussed herein. This information may be applied to the future treatment of skin diseases through the individual targeting of the ROS generated in each case via their inhibition, capture, or regulation.