Resveratrol ameliorates imiquimod-induced psoriasis-like skin inflammation in mice

Carboxymethyl cellulose-based rotigotine nanocrystals-loaded hydrogel for increased transdermal delivery with alleviated skin irritation

Transdermal rotigotine (RTG) therapy is prescribed to manage Parkinson's disease (Neupro® patch). However, its use is suffered from application site reactions. Herein, drug nanocrystalline suspension (NS)-loaded hydrogel (NS-HG) employing polysaccharides simultaneously as suspending agent and hydrogel matrix was constructed for transdermal delivery, with alleviated skin irritation. RTG-loaded NS-HG was prepared using a bead-milling technique, employing sodium carboxylmethyl cellulose (Na.CMC) as nano-suspending agent (molecular weight 90,000 g/mol) and hydrogel matrix (700,000 g/mol), respectively. NS-HG was embodied as follows: drug loading: ≤100 mg/mL; shape: rectangular crystalline; crystal size: <286.7 nm; zeta potential: -61 mV; viscosity: <2.16 Pa·s; and dissolution rate: >90 % within 15 min. Nuclear magnetic resonance analysis revealed that the anionic polymers bind to RTG nanocrystals via charge interaction, affording uniform dispersion in the matrix. Rodent transdermal absorption of RTG from NS-HG was comparable to that from microemulsions, and proportional to drug loading. Moreover, NS-HG was skin-friendly; erythema and epidermal swelling were absent after repeated application. Further, NS-HG was chemically stable; >95 % of the drug was preserved up to 4 weeks under long term (25 °C/RH60%), accelerated (40 °C/RH75%), and stress (50 °C) storage conditions. Therefore, this novel cellulose derivative-based nanoformulation presents a promising approach for effective transdermal RTG delivery with improved tolerability.

Granzyme K mediates IL-23-dependent inflammation and keratinocyte proliferation in psoriasis

Psoriasis is an inflammatory disease with systemic manifestations that most commonly presents as itchy, erythematous, scaly plaques on extensor surfaces. Activation of the IL-23/IL-17 pro-inflammatory signaling pathway is a hallmark of psoriasis and its inhibition is key to clinical management. Granzyme K (GzmK) is an immune cell-secreted serine protease elevated in inflammatory and proliferative skin conditions. In the present study, human psoriasis lesions exhibited elevated GzmK levels compared to non-lesional psoriasis and healthy control skin. In an established murine model of imiquimod (IMQ)-induced psoriasis, genetic loss of GzmK significantly reduced disease severity, as determined by delayed plaque formation, decreased erythema and desquamation, reduced epidermal thickness, and inflammatory infiltrate. Molecular characterization in vitro revealed that GzmK contributed to macrophage secretion of IL-23 as well as PAR-1-dependent keratinocyte proliferation. These findings demonstrate that GzmK enhances IL-23-driven inflammation as well as keratinocyte proliferation to exacerbate psoriasis severity.

The Role of Aryl Hydrocarbon Receptor in the Pathogenesis and Treatment of Psoriasis

The pathogenesis of psoriasis is complex. Aryl hydrocarbon receptor (AhR) is a transcription factor that can be bound and activated by structurally diverse ligands and plays an important role in a range of biological processes and in the pathogenesis of different diseases. Recently, the role of AhR in psoriasis has attracted attention. AhR has toxicological functions and physiological functions. The overexpression and activation of AhR induced by the environmental pollutant and exogenous AhR agonist 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) can drive the development of psoriasis. This TCDD-mediated toxicological response disrupts the physiological functions of AhR resulting in skin barrier disorders and the release of inflammatory cytokines, 2 of the pivotal factors of psoriasis. In addition, highly upregulated kynureninase in psoriasis decreases endogenous AhR agonists, thereby weakening the physiological functions of AhR. Activating AhR physiological signalling should be useful in the treatment of psoriasis. Studies have demonstrated that physiological activation of AhR can dampen the severity of psoriasis. The oldest and effective treatment for psoriasis coal tar works by activating AhR, and both new anti-psoriasis drugs tapinarof and benvitimod are formulations of AhR agonist, supporting that activation of AhR can be used as a new strategy for the treatment of psoriasis. Preclinical and preliminary clinical studies have revealed the anti-psoriasis effects of a number of AhR agonists, providing potential candidates for the development of new drugs for the treatment of psoriasis.

Bitter Phytochemicals as Novel Candidates for Skin Disease Treatment

Skin diseases represent a global healthcare challenge due to their rising incidence and substantial socio-economic burden. While biological, immunological, and targeted therapies have brought a revolution in improving quality of life and survival rates for certain dermatological conditions, there remains a stringent demand for new remedies. Nature has long served as an inspiration for drug development. Recent studies have identified bitter taste receptors (TAS2Rs) in both skin cell lines and human skin. Additionally, bitter natural compounds have shown promising benefits in addressing skin aging, wound healing, inflammatory skin conditions, and even skin cancer. Thus, TAS2Rs may represent a promising target in all these processes. In this review, we summarize evidence supporting the presence of TAS2Rs in the skin and emphasize their potential as drug targets for addressing skin aging, wound healing, inflammatory skin conditions, and skin carcinogenesis. To our knowledge, this is a pioneering work in connecting information on TAS2Rs expression in skin and skin cells with the impact of bitter phytochemicals on various beneficial effects related to skin disorders.

Resveratrol and Its Derivatives in Inflammatory Skin Disorders-Atopic Dermatitis and Psoriasis: A Review

Atopic dermatitis (AD) and psoriasis are inflammatory skin diseases whose prevalence has increased worldwide in recent decades. These disorders contribute to patients' decreased quality of life (QoL) and constitute a socioeconomic burden. New therapeutic options for AD and psoriasis based on natural compounds are being investigated. These include resveratrol (3,5,40-trihydroxystilbene) and its derivatives, which are produced by many plant species, including grapevines. Resveratrol has gained interest since the term "French Paradox", which refers to improved cardiovascular outcomes despite a high-fat diet in the French population, was introduced. Resveratrol and its derivatives have demonstrated various health benefits. In addition to anti-cancer, anti-aging, and antibacterial effects, there are also anti-inflammatory and antioxidant effects that can affect the molecular pathways of inflammatory skin disorders. A comprehensive understanding of these mechanisms may help develop new therapies. Numerous in vivo and in vitro studies have been conducted on the therapeutic properties of natural compounds. However, regarding resveratrol and its derivatives in treating AD and psoriasis, there are still many unexplained mechanisms and a need for clinical trials. Considering this, in this review, we discuss and summarize the most critical research on resveratrol and its derivatives in animal and cell models mimicking AD and psoriasis.

Investigating the gut microbiota's influence on psoriasis and psoriatic arthritis risk: a Mendelian randomization analysis

Background

Numerous investigations have revealed the interplay between gut microbiota (GM) and psoriasis (Ps) and psoriatic arthritis (PsA). However, the causal relationship between them remains unknown.

Methods

We curated a collection of genetic variants (P < 1 × 10-5) associated with GM (n = 18 340) derived from the MiBioGen study. To explore the intricate relationship between GM and Ps as well as PsA, we harnessed the comprehensive resources of the FinnGen database, encompassing a vast cohort of individuals, including 4510 Ps cases and 212 242 controls and 1637 PsA cases and 212 242 controls. Mendelian randomization (MR) was used, including an inverse variance weighting method, followed by a sensitivity analysis to verify the robustness of the results.

Results

For Ps, some bacterial taxa, including Lactococcus, Ruminiclostridium 5, and Eubacterium fissicatena, were identified as risk factors; but Odoribacter demonstrated a protective effect against Ps. In the case of PsA, Lactococcus, Verrucomicrobiales, Akkermansia, Coprococcus 1, and Verrucomicrobiaceae were identified as risk factors; Odoribacter and Rikenellaceae exhibited a protective effect against the development of PsA.

Conclusion

Our study establishes a causal link between the GM and Ps and PsA. These findings provide insights into the underlying mechanisms and suggest potential therapeutic targets.

Resveratrol Ameliorates Imiquimod-Induced Psoriasis-Like Mouse Model via Reducing Macrophage Infiltration and Inhibiting Glycolysis

Purpose

Resveratrol (Res) is a natural polyphenol with anti-inflammatory and immunomodulatory effects. Alterations in metabolic pathways have been studied in psoriasis. This study is aimed to further explore the potential molecular mechanism of psoriasis improvement by Res.

Patients and Methods

Imiquimod (IMQ)-induced psoriasis-like mouse model was established to observe the effects of Res. NanoString nCounter Metabolic Pathways Panel was used to analyze the changed mRNA and qRT-PCR was used for validation. Flow cytometry was used to analyze immune cell subsets in skin lesions. In vitro, we observed the effects of Res on R848-stimulated macrophages glycolysis and inflammation.

Results

Res reduced the proliferation of keratinocytes and the secretion of inflammatory cytokines in IMQ-induced psoriasis-like mouse model. Psoriasis model skin lesions were in a state of hypoxia, with upregulated glycolysis and downregulated AMPK activity. Res inhibited the levels of hypoxia-related genes (hif1α, hif3α) and glycolysis-related genes (hk1, ldha), meanwhile increased the levels of AMPK genes (prkaa1, prkaa2). Flow cytometry analysis revealed that Res decreased the infiltration of macrophages in psoriasis-like lesions. In addition, Res decreased the secretion of macrophage-associated pro-inflammatory cytokines (IL-23, TNF-α, IL-1β). In vitro, Res diminished the secretion of IL-23, TNF-α, IL-1β, and lactate by R848-stimulated macrophages and activated AMPK.

Conclusion

This study suggested that Res diminished psoriasis symptoms by inhibiting macrophages infiltration and inhibiting glycolysis, which providing novel insights into the underlying mechanisms of therapeutic action of Res in the treatment of psoriasis.

The Role of Sirtuins in the Pathogenesis of Psoriasis

Psoriasis is the most common chronic inflammatory skin disease with a genetic basis. It is characterised by keratinocyte hyperproliferation, parakeratosis and inflammatory cell infiltration. Psoriasis negatively affects a patient's physical and emotional quality of life. Sirtuins (SIRTs; silent information regulators) are an evolutionarily conserved group of enzymes involved in the post-translational modification of proteins, including deacetylation, polyADP-ribosylation, demalonylation and lipoamidation. SIRTs are involved in a number of cellular pathways related to ageing, inflammation, oxidative stress, epigenetics, tumorigenesis, the cell cycle, DNA repair and cell proliferation, positioning them as an essential component in the pathogenesis of many diseases, including psoriasis. Activation of SIRT1 counteracts oxidative-stress-induced damage by inhibiting the mitogen-activated protein kinases (MAPK), nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) and signal transducer and activator of transcription 3 (STAT3) pathways and may mitigate pathological events in psoriasis. There is a significant reduction in the expression of SIRT1, SIRT2, SIRT3, SIRT4 and SIRT5 and an increase in the expression of SIRT6 and SIRT7 in psoriasis. The aim of the review is to draw the attention of physicians and scientists to the importance of SIRTs in dermatology and to provide a basis and impetus for future discussions, research and pharmacological discoveries to modulate SIRT activity. In light of the analysis of the mode of action of SIRTs in psoriasis, SIRT1-SIRT5 agonists and SIRT6 and SIRT7 inhibitors may represent new therapeutic options for the treatment of psoriasis.

Potential of resveratrol in the treatment of interstitial lung disease

Interstitial lung disease (ILD) is a heterogeneous group of diseases characterized by lung injury caused by lung fibroblast proliferation, interstitial inflammation, and fibrosis. Different cell signal transduction pathways are activated in response to various proinflammatory or fibrotic cytokines, such as IL-6, and these cytokines are increased in different ILDs. The overexpressed cytokines and growth factors in ILD can activate TGF-β/Smad2/3/4, NF-κB, and JAK/STAT signal transduction pathways, promote the activation of immune cells, increase the release of pro-inflammatory and pro-fibrotic factors, differentiate fibroblasts into myofibroblasts, and promote the occurrence and development of ILD. This finding suggests the importance of signal transduction pathways in patients with ILD. Recent evidence suggests that resveratrol (RSV) attenuates excessive inflammation and pulmonary fibrosis by inhibiting the TGF-β/Smad2/3/4, NF-κB, and JAK/STAT signal transduction pathways and overactivation of immune cells. In this review, advances in lung protection and the underlying mechanisms of RSV are summarized, and the potential efficacy of RSV as a promising treatment option for ILD is highlighted.

Diosmin nanocrystal gel alleviates imiquimod-induced psoriasis in rats via modulating TLR7,8/NF-κB/micro RNA-31, AKT/mTOR/P70S6K milieu, and Tregs/Th17 balance

Diosmin is a flavonoid with promising anti-inflammatory and antioxidant properties. However, it has difficult physicochemical characteristics since its solubility demands a pH level of 12, which has an impact on the drug's bioavailability. The aim of this work is the development and characterization of diosmin nanocrystals using anti-solvent precipitation technique to be used for topical treatment of psoriasis. Results revealed that diosmin nanocrystals stabilized with hydroxypropyl methylcellulose (HPMC E15) in ratio (diosmin:polymer; 1:1) reached the desired particle size (276.9 ± 16.49 nm); provided promising colloidal properties and possessed high drug release profile. Additionally, in-vivo assessment was carried out to evaluate and compare the activities of diosmin nanocrystal gel using three different doses and diosmin powder gel in alleviating imiquimod-induced psoriasis in rats and investigating their possible anti-inflammatory mechanisms. Herein, 125 mg of 5% imiquimod cream (IMQ) was applied topically for 5 consecutive days on the shaved backs of rats to induce psoriasis. Diosmin nanocrystal gel especially in the highest dose used offered the best anti-inflammatory effect. This was confirmed by causing the most statistically significant reduction in the psoriasis area severity index (PASI) score and the serum inflammatory cytokines levels. Furthermore, it was capable of maintaining the balance between T helper (Th17) and T regulatory (Treg) cells. Moreover, it tackled TLR7/8/NF-κB, miRNA-31, AKT/mTOR/P70S6K and elevated the TNFAIP3/A20 (a negative regulator of NF-κB) expression in psoriatic skin tissues. This highlights the role of diosmin nanocrystal gel in tackling imiquimod-induced psoriasis in rats, and thus it could be a novel promising therapy for psoriasis.

Chinese Medicine as Supporting Therapy for Psoriasis: Past, Present, and Future

Psoriasis is a chronic skin disease and an important health concern. Western medicine and therapies are the main treatment strategies for psoriasis vulgaris (PV); however, the overall prognosis of patients with PV is still poor. Therefore, PV prevention is especially crucial. Chinese medicine (CM) has a long history of treating psoriasis, and it has unique wisdom in different cognitive angles and treatment modes from modern medicine. In this review, we first summarized the herbs and ancient CM formulas that have therapeutic effects on PV. Second, the research status and obstacles to the current development of CM in modern medicine were reviewed. Finally, the future of CM in the context of precision medicine and integrated medicine was discussed. After a detailed reading of the abundant literature, we believe that CM, through thousands of years of continuous development and clinical practice, has achieved high effectiveness and safety for PV treatment, despite its surrounding controversy. Moreover, precise analyses and systematic research methods have provided new approaches for the modernization of CM in the future. The treatment of PV with CM is worth popularizing, and we hope it can benefit more patients.

Possible Mechanisms of Oxidative Stress-Induced Skin Cellular Senescence, Inflammation, and Cancer and the Therapeutic Potential of Plant Polyphenols

As the greatest defense organ of the body, the skin is exposed to endogenous and external stressors that produce reactive oxygen species (ROS). When the antioxidant system of the body fails to eliminate ROS, oxidative stress is initiated, which results in skin cellular senescence, inflammation, and cancer. Two main possible mechanisms underlie oxidative stress-induced skin cellular senescence, inflammation, and cancer. One mechanism is that ROS directly degrade biological macromolecules, including proteins, DNA, and lipids, that are essential for cell metabolism, survival, and genetics. Another one is that ROS mediate signaling pathways, such as MAPK, JAK/STAT, PI3K/AKT/mTOR, NF-κB, Nrf2, and SIRT1/FOXO, affecting cytokine release and enzyme expression. As natural antioxidants, plant polyphenols are safe and exhibit a therapeutic potential. We here discuss in detail the therapeutic potential of selected polyphenolic compounds and outline relevant molecular targets. Polyphenols selected here for study according to their structural classification include curcumin, catechins, resveratrol, quercetin, ellagic acid, and procyanidins. Finally, the latest delivery of plant polyphenols to the skin (taking curcumin as an example) and the current status of clinical research are summarized, providing a theoretical foundation for future clinical research and the generation of new pharmaceuticals and cosmetics.

The Anti-Inflammatory and Immunomodulatory Activities of Natural Products to Control Autoimmune Inflammation

Inflammation is an integral part of autoimmune diseases, which are caused by dysregulation of the immune system. This dysregulation involves an imbalance between pro-inflammatory versus anti-inflammatory mediators. These mediators include various cytokines and chemokines; defined subsets of T helper/T regulatory cells, M1/M2 macrophages, activating/tolerogenic dendritic cells, and antibody-producing/regulatory B cells. Despite the availability of many anti-inflammatory/immunomodulatory drugs, the severe adverse reactions associated with their long-term use and often their high costs are impediments in effectively controlling the disease process. Accordingly, suitable alternatives are being sought for these conventional drugs. Natural products offer promising adjuncts/alternatives in this regard. The availability of specific compounds isolated from dietary/medicinal plant extracts have permitted rigorous studies on their disease-modulating activities and the mechanisms involved therein. Here, we describe the basic characteristics, mechanisms of action, and preventive/therapeutic applications of 5 well-characterized natural product compounds (Resveratrol, Curcumin, Boswellic acids, Epigallocatechin-3-gallate, and Triptolide). These compounds have been tested extensively in animal models of autoimmunity as well as in limited clinical trials in patients having the corresponding diseases. We have focused our description on predominantly T cell-mediated diseases, such as rheumatoid arthritis, multiple sclerosis, Type 1 diabetes, ulcerative colitis, and psoriasis.

A cutback in Imiquimod cutaneous toxicity; comparative cutaneous toxicity analysis of Imiquimod nanotransethosomal gel with 5% marketed cream on the BALB/c mice

Herein, Imiquimod (IMQ) was incorporated in nanotransethosomes (nTES) to develop the IMQ-nTES nano-drug delivery system. IMQ-nTES was optimized using 23 factorial design. The optimized formulation was expressed with a particle size of 192.4 ± 1.60 nm, Poly-dispersibility of 0.115 ± 0.008, and IMQ percent entrapment efficiency of 91.05 ± 3.22%. Smooth and round morphology of IMQ-nTES vesicles was confirmed by TEM micrographs. Moreover, FTIR results have shown drug-excipient compatibility. The IMQ-nTES was laden inside the low molecular weight chitosan gel, which exhibited easy application, spreadability and no irritation to the applied skin. The release pattern has clearly exhibited improved dissolution properties of IMQ with the provision of the sustain release pattern. Higher IMQ content was deposited in deeper epidermis and dermis with IMQ-nTES gel, in contrast to ALDARA. In vivo, comparative toxicity study on BALB/c mice has shown significantly reduced (p < 0.001) psoriatic area severity index (PASI) score and less increment in ear thickness. Epidermal hyperplasia was an obvious finding with ALDARA which was, providentially, minimal in IMQ-nTES gel-treated skin. FTIR analysis of skin tissue has shown an enhancement of lipid and protein content in the ALDARA group, however, in the IMQ-nTES group no such change was observed. With ALDARA application, CD4+ T-cells and constitutive NF-κβ expression were significantly elevated, in comparison to the IMQ-nTES gel treated group. Moreover, the adequate expression of IFN-γ and cytotoxic CD8+ T-cells were suggesting the preserved IMQ efficacy with IMQ-nTES gel. Quantification of cutaneous as well as systemic inflammatory markers has also suggested the reduced psoriatic potential of IMQ-nTES gel. In essence, IMQ-nTES gel can be a suitable alternative to ALDARA owing to its better safety profile.

The lncRNA PRINS-miRNA-mRNA Axis Gene Expression Profile as a Circulating Biomarker Panel in Psoriasis

BACKGROUND

The interaction between genes and the environment in psoriasis is firmly coupled by epigenetic modification. Epigenetic modifications are inherited variations in gene expression devoid of DNA sequence alterations. Non-coding RNAs are regarded as one of the epigenetic modifications that lead eventually to enduring heritable variations in gene expression. In the present study, we chose the lncRNA, Psoriasis-susceptibility-Related RNA Gene Induced by Stress (PRINS) known to have a regulatory role in psoriasis and deduced its axis of lncRNA-miRNA-mRNA through an in silico data analysis. We aimed to assess the expression levels of this lncRNA-miRNA-mRNA in patients with psoriasis to elucidate their possible roles in psoriasis management.

METHODS

We investigated the lncRNA-PRINS and its target microRNAs (miRNA124-3p, miRNA203a-5p, miRNA129-5p, miRNA146a-5p, miRNA9-5p) and partner genes (NPM, G1P3) expression levels in the plasma of 120 patients with psoriasis compared to 120 healthy volunteers using quantitative real-time polymerase chain reaction and correlated the results with the patients' clinicopathological data. Finally, we performed a function, disease, and pathway enrichment analysis for the LncRNA-miRNA-mRNA axis under study.

RESULTS

The lncRNA PRINS, G1P3, and NPM genes showed significantly under-expressed levels while all miRNAs included in the study showed significant over-expression in patients with psoriasis relative to controls. The lncRNA PRINS, G1P3, and NPM genes showed a significant direct correlation with each other and inverse significant correlations with all miRNAs under study. All the study biomarkers showed significant results for discriminating between patients with psoriasis and controls using a receiver operating curve analysis with sensitivity over 90% except for PRINS, which was 74.2%. The G1P3 gene showed a direct significant correlation with body mass index in patients with psoriasis (p = 0.009) and an inverse significant correlation with age (p = 0.034). The NPM gene showed a significant correlation with body mass index in patients with psoriasis (p = 0.002).

CONCLUSIONS

Based on our results, we suggest that restoring the altered PRINS-miRNA-mRNA axis gene expression levels might represent a tool to prevent psoriasis worsening, along with standard therapy. Thus, on the clinical practice level, the PRINS-miRNA-mRNA axis expression profile can be utilized in designing specific targeted therapy aimed at applying a personalized medicine approach among patients with psoriasis.

3, 3'- diindolylmethane hinders IL-17A/IL-17RA interaction and mitigates imiquimod-induced psoriasiform in mice

Psoriasis is a highly inflammatory autoimmune-mediated skin disease. The strongest evidence has pointed to the influential role of interleukin (IL) -17A in the aberrant pathology of psoriasis. Henceforth, targeting the IL-17A cytokine is of prime importance in controlling the disease severity of psoriasis. Reportedly, 3, 3'- diindolylmethane (DIM) is a phytochemical that alleviated acute atopic dermatitis. Howbeit, the therapeutic intervention of DIM against IL-17A/IL-17RA interaction and its signaling mediated pathogenesis in psoriasis remains unexplored. In the current report, we decoded the molecular basis of DIM in psoriasis. Docking analysis has reported that DIM identified an IL-17A binding region in the functional fibronectin-III-like domain of IL-17RA and abrogated IL-17A/IL-17RA interaction. In-vitro experiments demonstrated that DIM impeded IL-17A mediated hyper-proliferative phenotype of psoriatic-like keratinocytes. Furthermore, DIM abated the catabolic effects of IL-17A stimulated expression of pathogenic mediators like HMGB-1, Cyr-61, CCL-20, and VEGF via blunted activation of JAK/STAT pathway in psoriatic like keratinocytes. Profoundly, DIM restricted the reprogramming of psoriatic-like keratinocytes to overexpress IL-17RA in concert with IL-17A stimulation. In line with in-vitro studies, DIM also ameliorated skin lesions and epidermal hyperplasia in an imiquimod-induced mice model of psoriasis. Additionally, DIM also reduced STAT-3 phosphorylation and associated expression of Cyr-61, CCL-20, and VEGF in psoriatic mice. However, if DIM has a direct effect on STAT-3 inhibition or it negatively regulates STAT-3 function via blockade of IL-17A/IL-17RA interaction needs to be investigated in the future. Conclusively, our studies demonstrated that the blockade of IL-17A/IL-17RA interaction is a novel therapeutic perspective of DIM against the progression of psoriasis disease.

Chloroform Extract of Plumbago zeylanica Linn. Roots Ameliorates the Epidermal Thickness of Imiquimod-induced Psoriatic Mice through Cell Cycle and Apoptosis

Introduction: Psoriasis vulgaris is a chronic skin disease which is characterized by recurrent scales on skin. The global prevalence of this disease has increased in ten years. Plumbagin is an active compound in the P. zeylanica Linn. Some recent studies revealed that P. zeylanica Linn extracts have the antiproliferative activity, which is used for treatment of some human diseases. The aim of this study was to investigated the effect of Chloroform extract of P. zeylanica Linn roots (CEP) on epidermal thickness of Imiquimod-induced psoriatic mice. Methods: This was a post-test only control group design. A total of 42 male BALB/c mice was divided into six groups. Mice in treatment groups orally received 25, 50, and 100 mg/kg body weight CEP, respectively while positive control orally received 1 mg/kg body weight Methotrexate for seven days. Evaluation of epidermal thickness based on histological changes, serum IL-23 level by ELISA, and Cyclin-dependent kinase 2, Cyclin A, and Caspase-3 expressions by immunohistochemistry. Results: Administrations of CEP decreased the epidermal thickness of psoriatic plaques in all treatment groups (p = 0.002, 0.003, and 0.016 respectively) compared to negative control but it did not reduce the serum IL-23 level.  The expressions of CDK2 and Cyclin A reduced in T2 and T3 groups and the expression of Caspase-3 increased was only in T3 group. Conclusion: Chloroform extract of P. zeylanica Linn roots administrations reduce the epidermal thickness of Imiquimod-induced psoriatic mice by inhibition of keratinocyte cell cycle and induction of Caspase-3 expression.

Peroxisome proliferator-activator receptor γ and psoriasis, molecular and cellular biochemistry

The pathophysiology of psoriasis is complex and has not been completely elucidated. Better understanding of the pathogenesis may contribute to further improvement of our therapeutic strategies controlling psoriasis. Emerging evidence points to a causative relationship between altered activity of peroxisome proliferator-activated receptor γ (PPARγ) and psoriasis. The present review focuses on deeper understanding of the possible role of PPARγ in the pathogenesis of psoriasis and the potential of PPARγ agonist to improve the treatment of psoriasis. PPARγ is decreased in psoriasis. PPARγ possibly has effects on the multiple aspects of the pathogenesis of psoriasis, including abnormal lipid metabolism, insulin resistance, immune cells, pro-inflammatory cytokines, keratinocytes, angiogenesis, oxidative stress, microRNAs and nuclear factor kappa B. As defective activation of PPARγ is involved in psoriasis development, PPARγ agonists may be promising agents for treatment of psoriasis. Pioglitazone appears an effective and safe option in the treatment of patients with psoriasis, but there are still concerns about its potential side effects. Research effort has recently been undertaken to explore the PPARγ-activating potential of natural products. Among them some have been studied clinically or preclinically for treatment of psoriasis with promising results.

Promising Natural Products in New Drug Design, Development, and Therapy for Skin Disorders: An Overview of Scientific Evidence and Understanding Their Mechanism of Action

The skin is the largest organ in the human body, composed of the epidermis and the dermis. It provides protection and acts as a barrier against external menaces like allergens, chemicals, systemic toxicity, and infectious organisms. Skin disorders like cancer, dermatitis, psoriasis, wounds, skin aging, acne, and skin infection occur frequently and can impact human life. According to a growing body of evidence, several studies have reported that natural products have the potential for treating skin disorders. Building on this information, this review provides brief information about the action of the most important in vitro and in vivo research on the use of ten selected natural products in inflammatory, neoplastic, and infectious skin disorders and their mechanisms that have been reported to date. The related studies and articles were searched from several databases, including PubMed, Google, Google Scholar, and ScienceDirect. Ten natural products that have been reported widely on skin disorders were reviewed in this study, with most showing anti-inflammatory, antioxidant, anti-microbial, and anti-cancer effects as the main therapeutic actions. Overall, most of the natural products reported in this review can reduce and suppress inflammatory markers, like tumor necrosis factor-alpha (TNF-α), scavenge reactive oxygen species (ROS), induce cancer cell death through apoptosis, and prevent bacteria, fungal, and virus infections indicating their potentials. This review also highlighted the challenges and opportunities of natural products in transdermal/topical delivery systems and their safety considerations for skin disorders. Our findings indicated that natural products might be a low-cost, well-tolerated, and safe treatment for skin diseases. However, a larger number of clinical trials are required to validate these findings. Natural products in combination with modern drugs, as well as the development of novel delivery mechanisms, represent a very promising area for future drug discovery of these natural leads against skin disorders.

Deep-learning approach for automated thickness measurement of epithelial tissue and scab using optical coherence tomography

SIGNIFICANCE

In order to elucidate therapeutic treatment to accelerate wound healing, it is crucial to understand the process underlying skin wound healing, especially re-epithelialization. Epidermis and scab detection is of importance in the wound healing process as their thickness is a vital indicator to judge whether the re-epithelialization process is normal or not. Since optical coherence tomography (OCT) is a real-time and non-invasive imaging technique that can perform a cross-sectional evaluation of tissue microstructure, it is an ideal imaging modality to monitor the thickness change of epidermal and scab tissues during wound healing processes in micron-level resolution. Traditional segmentation on epidermal and scab regions was performed manually, which is time-consuming and impractical in real time.

AIM

We aim to develop a deep-learning-based skin layer segmentation method for automated quantitative assessment of the thickness of in vivo epidermis and scab tissues during a time course of healing within a rodent model.

APPROACH

Five convolution neural networks were trained using manually labeled epidermis and scab regions segmentation from 1000 OCT B-scan images (assisted by its corresponding angiographic information). The segmentation performance of five segmentation architectures was compared qualitatively and quantitatively for validation set.

RESULTS

Our results show higher accuracy and higher speed of the calculated thickness compared with human experts. The U-Net architecture represents a better performance than other deep neural network architectures with 0.894 at F1-score, 0.875 at mean intersection over union, 0.933 at Dice similarity coefficient, and 18.28  μm at an average symmetric surface distance. Furthermore, our algorithm is able to provide abundant quantitative parameters of the wound based on its corresponding thickness maps in different healing phases. Among them, normalized epidermal thickness is recommended as an essential hallmark to describe the re-epithelialization process of the rodent model.

CONCLUSIONS

The automatic segmentation and thickness measurements within different phases of wound healing data demonstrates that our pipeline provides a robust, quantitative, and accurate method for serving as a standard model for further research into effect of external pharmacological and physical factors.

Resveratrol and cyclodextrins, an easy alliance: Applications in nanomedicine, green chemistry and biotechnology

Most drugs or the natural substances reputed to display some biological activity are hydrophobic molecules that demonstrate low bioavailability regardless of their mode of absorption. Resveratrol and its derivatives belong to the chemical group of stilbenes; while stilbenes are known to possess very interesting properties, these are limited by their poor aqueous solubility as well as low bioavailability in animals and humans. Among the substances capable of forming nanomolecular inclusion complexes which can be used for drug delivery, cyclodextrins show spectacular physicochemical and biomedical implications in stilbene chemistry for their possible application in nanomedicine. By virtue of their properties, cyclodextrins have also demonstrated their possible use in green chemistry for the synthesis of stilbene glucosylated derivatives with potential applications in dermatology and cosmetics. Compared to chemical synthesis and genetically modified microorganisms, plant cell or tissue systems provide excellent models for obtaining stilbenes in few g/L quantities, making feasible the production of these compounds at a large scale. However, the biosynthesis of stilbenes is only possible in the presence of the so-called elicitor compounds, the most commonly used of which are cyclodextrins. We also report here on the induction of resveratrol production by cyclodextrins or combinatory elicitation with methyljasmonate in plant cell systems as well as the mechanisms by which they are able to trigger a stilbene response. The present article therefore discusses the role of cyclodextrins in stilbene chemistry both at the physico-chemical level as well as the biomedical and biotechnological levels, emphasizing the notion of "easy alliance" between these compounds and stilbenes.

Lysophosphatidic Acid Mediates Imiquimod-Induced Psoriasis-like Symptoms by Promoting Keratinocyte Proliferation through LPAR1/ROCK2/PI3K/AKT Signaling Pathway

Psoriasis is a chronic inflammatory skin disease. Recently, lysophosphatidic acid (LPA)/LPAR5 signaling has been reported to be involved in both NLRP3 inflammasome activation in macrophages and keratinocyte activation to produce inflammatory cytokines, contributing to psoriasis pathogenesis. However, the effect and molecular mechanisms of LPA/LPAR signaling in keratinocyte proliferation in psoriasis remain unclear. In this study, we investigated the effects of LPAR1/3 inhibition on imiquimod (IMQ)-induced psoriasis-like mice. Treatment with the LPAR1/3 antagonist, ki16425, alleviated skin symptoms in IMQ-induced psoriasis-like mouse models and decreased keratinocyte proliferation in the lesion. It also decreased LPA-induced cell proliferation and cell cycle progression via increased cyclin A2, cyclin D1, cyclin-dependent kinase (CDK)2, and CDK4 expression and decreased p27^Kip1 expression in HaCaT cells. LPAR1 knockdown in HaCaT cells reduced LPA-induced proliferation, suppressed cyclin A2 and CDK2 expression, and restored p27^Kip1 expression. LPA increased Rho-associated protein kinase 2 (ROCK2) expression and PI3K/AKT activation; moreover, the pharmacological inhibition of ROCK2 and PI3K/AKT signaling suppressed LPA-induced cell cycle progression. In conclusion, we demonstrated that LPAR1/3 antagonist alleviates IMQ-induced psoriasis-like symptoms in mice, and in particular, LPAR1 signaling is involved in cell cycle progression via ROCK2/PI3K/AKT pathways in keratinocytes.

Resveratrol-Loaded Vesicular Elastic Nanocarriers Gel in Imiquimod-Induced Psoriasis Treatment: In Vitro and In Vivo Evaluation

This work aimed to develop a new efficient approach for safe treatment of psoriasis. To achieve that, resveratrol-loaded spanlastics(F1-F12) were prepared and evaluated by complete in vitro characterization. The two optimal formulations (F10 and F11) had their particle size in the nano range with high entrapment efficiency and sustainable drug release. These two formulae were incorporated in carbopol 934 gel formulations (G1-G8) with different concentrations of drug and carbopol 934 polymer. G1 and G5 (1% w/w Carbopol 934 gel and 0.1% resveratrol) showed 40.13% ± 2.017% and 73.76% ± 2.46%,8 hours drug release, respectively. Their pH was accepted and non-irritant. At a shear stress of 500 s^-1, G1 and G5 showed a reasonable viscosity of 1048.5 ± 2.12 cps and 954 ± 2.15 cps, respectively. In the in vivo psoriasis study, mice treated by G5 gel showed significant improvement of erythema and scaling compared to positive control group and they maintained healthy skin as shown in histopathological observations. Moreover, this group showed the least changes in mRNA expression of inflammatory cytokines. Concisely, our results suggest that selected carbopol gel of resveratrol-loaded spanlastics could maximize resveratrol topical anti-psoriatic effect.

Anoctamin1 Induces Hyperproliferation of HaCaT Keratinocytes and Triggers Imiquimod-Induced Psoriasis-Like Skin Injury in Mice

Psoriasis, a long-lasting and multifactorial skin disease, is related to comorbidities such as metabolic disease, depression, and psoriatic arthritis. Psoriasis occurs due to a variety of factors including keratinocyte hyperproliferation, inflammation, and abnormal differentiation. Proinflammatory cytokines upregulated by increased activation of keratinocytes and immune cells in the skin trigger progression of psoriasis. This study aimed to investigate the effects of anoctamin1 (ANO1) on psoriasis development in vitro and in vivo. We analyzed the proliferation of HaCaT keratinocytes and ANO1-related ERK and AKT signaling pathways after ANO1 inhibitor (T16Ainh-A01 and Ani9) treatment and knock-down of ANO1. Furthermore, after applying imiquimod (IMQ) cream or coapplying IMQ cream and T16Ainh-A01 on mouse ears, we not only observed psoriatic symptoms, including ear thickening, but also quantified the effects of treatment on ERK and AKT signaling-involved proteins and proinflammatory cytokines. Inhibition of ANO1 attenuated the proliferation of HaCaT cells and induced reduction of pERK1/2. Coapplication of IMQ and T16Ainh-A01 on ears of mice reduced not only symptoms of IMQ-induced psoriasis such as thickening and erythema, but also expression of ANO1 and pERK1/2 compared to that of application of IMQ alone. In addition, the expression levels of IL-17A, IL-17F, IL-22, IL-23, IL-6, IL-1β, and TNF-α increased after applying IMQ and were significantly reduced by coapplying IMQ and T16Ainh-A01. These results aid in understanding the underlying mechanisms of ANO1 in epidermal layer keratinocyte hyperproliferation and suggest the potential of ANO1 as a target to treat psoriasis.

The impact of resveratrol on skin wound healing, scarring, and aging

Resveratrol is a well‐known antioxidant that harbours many health beneficial properties. Multiple studies associated the antioxidant, anti‐inflammatory, and cell protective effects of resveratrol. These diverse effects of resveratrol are also potentially involved in cutaneous wound healing, scarring, and (photo‐)aging of the skin. Hence, this review highlighted the most relevant studies involving resveratrol in wound healing, scarring, and photo‐aging of the skin. A systematic review was performed and the database PubMed was searched for suitable publications. Only original articles in English that investigated the effects of resveratrol in wound healing, scarring, and (photo‐)aging of the skin were analysed. The literature search yielded a total of 826 studies, but only 41 studies met the inclusion criteria. The included studies showed promising results that resveratrol might be a feasible treatment approach to support wound healing, counteract excessive scarring, and even prevent photo‐aging of the skin. Resveratrol represents an interesting and promising novel therapy regime but to confirm resveratrol‐associated effects, more evidence based in vitro and in vivo studies are needed.

Advances in the Application of Natural Products and the Novel Drug Delivery Systems for Psoriasis

Psoriasis, an incurable autoimmune skin disease, is one of the most common immune-mediated disorders. Presently, numerous clinical research studies are underway, and treatment options are available. However, these treatments focus on improving symptoms of the disease and fail to achieve a radical cure; they also have certain toxic side effects. In recent years, natural products have increasingly gained attention because of their high efficiency and low toxicity. Despite their obvious therapeutic effects, natural products’ biological activity was limited by their instability, poor solubility, and low bioavailability. Novel drug delivery systems, including liposomes, lipospheres, nanostructured lipid carriers, niosomes, nanoemulsions, nanospheres, microneedles, ethosomes, nanocrystals, and foams could potentially overcome the limitations of poor water solubility and permeability in traditional drug delivery systems. Thus, to achieve a therapeutic effect, the drug can reach the epidermis and dermis in psoriatic lesions to interact with the immune cells and cytokines.

The Effect of Antioxidant and Anti-Inflammatory Capacity of Diet on Psoriasis and Psoriatic Arthritis Phenotype: Nutrition as Therapeutic Tool?

Chronic inflammation and increased oxidative stress are contributing factors to many non-communicable diseases. A growing body of evidence indicates that dietary nutrients can activate the immune system and may lead to the overproduction of pro-inflammatory cytokines. Fatty acids as macronutrients are key players for immunomodulation, with n-3 polyunsaturated fatty acids having the most beneficial effect, while polyphenols and carotenoids seem to be the most promising antioxidants. Psoriasis is a chronic, immune-mediated inflammatory disease with multifactorial etiology. Obesity is a major risk factor for psoriasis, which leads to worse clinical outcomes. Weight loss interventions and, generally, dietary regimens such as gluten-free and Mediterranean diet or supplement use may potentially improve psoriasis’ natural course and response to therapy. However, data about more sophisticated nutritional patterns, such as ketogenic, very low-carb or specific macro- and micro-nutrient substitution, are scarce. This review aims to present the effect of strictly structured dietary nutrients, that are known to affect glucose/lipid metabolism and insulin responses, on chronic inflammation and immunity, and to discuss the utility of nutritional regimens as possible therapeutic tools for psoriasis and psoriatic arthritis.

Chemical profiling and anti-psoriatic activity of marine sponge (Dysidea avara) in induced imiquimod-psoriasis-skin model

Since Marine sponge Dysidea avara is regarded as a source of anti-inflammatory compounds, we decided to evaluate its potential anti-psoriatic activity in a psoriasis Imiquimod-induced in the mouse model. Psoriatic mice were treated with three different methanolic extracts of Dysidea avara compared with betamethasone-treated mice in in- vivo studies. Clinical skin severity was assessed with the psoriasis area index (PASI), whilst ELISA detected the expression of TNF-α, IL-17A, and IL-22. Dysidea avara activity was studied by employing GC-MS (to distinguish compounds), HPTLC (for skin permeation and accumulation), and SEA DOCK to predict single compound potential anti-inflammatory activity. After 7 days of treatment, mice treated with Dysidea avara displayed a dose-dependent, statistically significant improvement compared to controls (p< 0.001). In line with the clinical results, ELISA revealed a statistically significant decrease in IL-22, IL-17A, and TNF-α after treatment; the same SEA DOCK analysis suggests a possible anti-psoriatic activity of the extracts.

Novel nanoemulsion gel containing triple natural bio-actives combination of curcumin, thymoquinone, and resveratrol improves psoriasis therapy: in vitro and in vivo studies

Curcumin, resveratrol, and thymoquinone are the potential natural bio-actives reported with good anti-psoriatic activity. However, poor aqueous solubility and limited skin permeation of these natural bio-actives hinder their effective delivery and potential therapeutic outcome. In this regard, current research work focuses on the design and optimization of nanoemulsion (NE) gel formulation for the concurrent delivery of these three drugs. The NE system is consisting of oleic acid as oil phase, Tween 20 as surfactant, and PEG 200 as co-surfactant. The optimized formulation exhibited the droplet size 76.20 ± 1.67 nm, PDI of 0.12 ± 0.05, RI of 1.403 ± 0.007, and viscosity of 137.9 ± 4.07 mp. Carbopol 940 (0.5% w/v) was used as the gelling agent to prepare the NE gel which exhibited a good texture profile. The optimized formulation exhibited a higher % of growth inhibition on A-431 cells and demonstrated good anti-angiogenic activity in the HET-CAM test. Finally, in vivo studies in Balb/c mice model showed improved anti-psoriatic conditions which indicated that the triple natural bio-actives combination in nanoemulgel formulation is effective in the management of psoriasis.

Virus-Induced Asthma Exacerbations: SIRT1 Targeted Approach

The prevalence of asthma has increased worldwide. Asthma exacerbations triggered by upper respiratory tract viral infections remain a major clinical problem and account for hospital admissions and time lost from work. Virus-induced asthma exacerbations cause airway inflammation, resulting in worsening asthma and deterioration in the patients’ quality of life, which may require systemic corticosteroid therapy. Despite recent advances in understanding the cellular and molecular mechanisms underlying asthma exacerbations, current therapeutic modalities are inadequate for complete prevention and treatment of these episodes. The pathological role of cellular senescence, especially that involving the silent information regulator 2 homolog sirtuin (SIRT) protein family, has recently been demonstrated in stable and exacerbated chronic respiratory disease states. This review discusses the role of SIRT1 in the pathogenesis of bronchial asthma. It also discusses the role of SIRT1 in inflammatory cells that play an important role in virus-induced asthma exacerbations. Recent studies have hypothesized that SIRT1 is one of major contributors to cellular senescence. SIRT1 levels decrease in Th2 and non-Th2-related airway inflammation, indicating the role of SIRT1 in several endotypes and phenotypes of asthma. Moreover, several models have demonstrated relationships between viral infection and SIRT1. Therefore, targeting SIRT1 is a novel strategy that may be effective for treating virus-induced asthma exacerbations in the future.

Lysophosphatidic Acid Receptor 5 Contributes to Imiquimod-Induced Psoriasis-Like Lesions through NLRP3 Inflammasome Activation in Macrophages

The pathogenesis of psoriasis, an immune-mediated chronic skin barrier disease, is not fully understood yet. Here, we identified lysophosphatidic acid (LPA) receptor 5 (LPA₅)-mediated signaling as a novel pathogenic factor in psoriasis using an imiquimod-induced psoriasis mouse model. Amounts of most LPA species were markedly elevated in injured skin of psoriasis mice, along with LPA₅ upregulation in injured skin. Suppressing the activity of LPA₅ with TCLPA5, a selective LPA₅ antagonist, improved psoriasis symptoms, including ear thickening, skin erythema, and skin scaling in imiquimod-challenged mice. TCLPA5 administration attenuated dermal infiltration of macrophages that were found as the major cell type for LPA₅ upregulation in psoriasis lesions. Notably, TCLPA5 administration attenuated the upregulation of macrophage NLRP3 in injured skin of mice with imiquimod-induced psoriasis. This critical role of LPA₅ in macrophage NLRP3 was further addressed using lipopolysaccharide-primed bone marrow-derived macrophages. LPA exposure activated NLRP3 inflammasome in lipopolysaccharide-primed cells, which was evidenced by NLRP3 upregulation, caspase-1 activation, and IL-1β maturation/secretion. This LPA-driven NLRP3 inflammasome activation in lipopolysaccharide-primed cells was significantly attenuated upon LPA₅ knockdown. Overall, our findings establish a pathogenic role of LPA₅ in psoriasis along with an underlying mechanism, further suggesting LPA₅ antagonism as a potential strategy to treat psoriasis.

Importance of Redox Equilibrium in the Pathogenesis of Psoriasis-Impact of Antioxidant-Rich Diet

Psoriasis is a common, chronic, hyperproliferative, inflammatory skin disease occurring in most ethnic groups in the world. The disease is hereditary but the process of its inheritance is complex and still not fully understood. At the same time, it has been observed that psoriatic lesions may be triggered by certain prooxidative external factors: using narcotics, smoking, drinking alcohol, physical and mental stress, as well as bacterial infections and injury. Since the main physiological marker of psoriasis relates to disorders in the organism's antioxidative system, it is necessary to develop a well-balanced combination of pharmaceuticals and dietary antioxidants to facilitate the effective treatment and/or prevention of the disease. The dietary sources of antioxidants must be adequate for chronic use regardless of the patient's age and be easily available, e.g., as ingredients of regular food or dietary supplements. Diet manipulation is a promising therapeutic approach in the context of modulating the incidence of chronic diseases. Another potentially viable method entails the use of nutrigenomics, which guarantees a multiaspectual approach to the problem, including, in particular, analyses of the genetic profiles of psoriasis patients with the view to more accurately targeting key problems. The present paper pertains to the significance of redox equilibrium in the context of psoriasis. Based on information published in worldwide literature over the last decade, the impact of dietary exogenous antioxidants on the course of this chronic disease was analysed.

Enhanced wound healing via collagen-turnover-driven transfer of PDGF-BB gene in a murine wound model

Wound healing is a complex biological process that requires coordinated cell proliferation, migration, and extracellular matrix production/remodeling, all of which are inhibited/delayed in chronic wounds. In this study, a formulation was developed that marries a fibrin-based, provisional-like matrix with collagen mimetic peptide (CMP)/PDGF gene-modified collagens, leading to the formation of robust gels that supported temporally controlled PDGF expression and facile application within the wound bed. Analysis employing in vitro co-gel scaffolds confirmed sustained and temporally controlled gene release based on matrix metalloproteinase (MMP) activity, with ~30% higher PDGF expression in MMP producing fibroblasts as-compared with non-MMP-expressing cells. The integration of fibrin with the gene-modified collagens resulted in co-gels that strongly supported both fibroblast cell recruitment/invasion as well as multiple aspects of the longer-term healing process. The excisional wound healing studies in mice established faster wound closure using CMP-modified PDGF polyplex-loaded co-gels, which exhibited up to 24% more wound closure (achieved with ~2 orders of magnitude lower growth factor dosing) after 9 days as compared to PDGF-loaded co-gels, and 19% more wound closure after 9 days as compared to CMP-free polyplex loaded co-gels. Moreover, minimal scar formation as well as improved collagen production, myofibroblast activity, and collagen orientation was observed following CMP-modified PDGF polyplex-loaded co-gel application on wounds. Taken together, the combined properties of the co-gels, including their stability and capacity to control both cell recruitment and cell phenotype within the murine wound bed, strongly supports the potential of the co-gel scaffolds for improved treatment of chronic non-healing wounds.

Role of Resveratrol in Regulating Cutaneous Functions

Protective role of the skin is against external insults and maintenance of electrolyte homeostasis of the body. Cutaneous dysfunction can account for the development of both cutaneous and systemic disorders. Thus, improvements in cutaneous functions can benefit a number of extracutaneous and cutaneous functions. Resveratrol, a natural ingredient, displays multiple benefits for various systems/organs, including the skin. The benefits of resveratrol for cutaneous functions include stimulation of keratinocyte differentiation and antimicrobial peptide expression, inhibition of keratinocyte proliferation and cutaneous inflammation, UV protection, anticancer, antiaging, and inhibition of melanogenesis. The mechanisms of action of resveratrol include activation of sirtuin 1 and nuclear factor erythroid 2-related factor 2, and inhibition of mitogen-activated protein kinase signaling. Evidence suggests that topical resveratrol could be a valuable alternative not only for daily skin care, but also for the prevention and treatment of various cutaneous disorders. This review summarizes the benefits of resveratrol for cutaneous functions.

Molecular Basis of the Beneficial Actions of Resveratrol

Resveratrol modulates the transcription factor NF-κB, cytochrome P450 isoenzyme CYP1A1, expression and activity of cyclooxygenase (COX) enzymes, Fas/Fas ligand mediated apoptosis, p53, mTOR and cyclins and various phospho-diesterases resulting in an increase in cytosolic cAMP levels. Cyclic AMP, in turn, activates Epac1/CaMKKβ/AMPK/SIRT1/PGC-1α pathway that facilitates increased oxidation of fatty acids, mitochondrial respiration and their biogenesis and gluconeogenesis. Resveratrol triggers apoptosis of activated T cells and suppresses tumor necrosis factor-α (TNF-α), interleukin-17 (IL-17) and other pro-inflammatory molecules and inhibits expression of hypoxia inducible factor-1α (HIF-1α) and vascular endothelial growth factor (VEGF) that may explain its anti-inflammatory actions. Polyunsaturated fatty acids (PUFAs) and their anti-inflammatory metabolites lipoxin A4, resolvins, protectins and maresins have a significant role in obesity, type 2 diabetes mellitus (T2DM), metabolic syndrome and cancer. We observed that PUFAs (especially arachidonic acid, AA) and BDNF (brain-derived neurotrophic factor) protect against the cytotoxic actions of alloxan, streptozotocin, benzo(a)pyrene (BP) and doxorubicin. Thus, there is an overlap in the beneficial actions of resveratrol, PUFAs and BDNF suggesting that these molecules may interact and augment synthesis and action of each other. This is supported by the observation that resveratrol and PUFAs modulate gut microbiota and influence stem cell proliferation and differentiation. Since resveratrol is not easily absorbed from the gut it is likely that it may act on endocannabinoid and light, odor, and taste receptors located in the gut, which, in turn, convey their messages to the various organs via vagus nerve.

Recent Advances on the Anti-Inflammatory and Antioxidant Properties of Red Grape Polyphenols: In Vitro and In Vivo Studies

In this review, special emphasis will be placed on red grape polyphenols for their antioxidant and anti-inflammatory activities. Therefore, their capacity to inhibit major pathways responsible for activation of oxidative systems and expression and release of proinflammatory cytokines and chemokines will be discussed. Furthermore, regulation of immune cells by polyphenols will be illustrated with special reference to the activation of T regulatory cells which support a tolerogenic pathway at intestinal level. Additionally, the effects of red grape polyphenols will be analyzed in obesity, as a low-grade systemic inflammation. Also, possible modifications of inflammatory bowel disease biomarkers and clinical course have been studied upon polyphenol administration, either in animal models or in clinical trials. Moreover, the ability of polyphenols to cross the blood-brain barrier has been exploited to investigate their neuroprotective properties. In cancer, polyphenols seem to exert several beneficial effects, even if conflicting data are reported about their influence on T regulatory cells. Finally, the effects of polyphenols have been evaluated in experimental models of allergy and autoimmune diseases. Conclusively, red grape polyphenols are endowed with a great antioxidant and anti-inflammatory potential but some issues, such as polyphenol bioavailability, activity of metabolites, and interaction with microbiota, deserve deeper studies.

Repurposing an old drug for new use: Niclosamide in psoriasis-like skin inflammation

Drug discovery is an onerous, extremely expensive, and time-consuming process. Instead, drug repurposing is an attractive strategy for exploiting novel indications for a drug beyond its original use. The untapped potential of drug repurposing compensates the barriers associated with the drug discovery pipeline. Psoriasis is an autoimmune skin disease, where hyperproliferation of keratinocytes and exaggerated immune responses are the important hallmarks of the disease. Extensive in vitro and preclinical research has demonstrated that niclosamide was found to exert potent anticancer and anti-inflammatory properties by targeting STAT3, p65 NF-κB, and NFATc-1 signaling paradigm with minimal host toxicity. From the disease perspective, the static intracellular molecular network in both cancer and psoriasis share overlapping pathological features in terms of hyperproliferation and chronic inflammation, which is mediated by the aforementioned signaling cascade. The plausible mechanistic relevance has prompted us to investigate the implementation of niclosamide for repositioning in psoriasis. Our in vitro and in vivo findings suggest that niclosamide inhibits keratinocytes hyperproliferation by reactive oxygen species-mediated apoptosis through the loss of mitochondrial membrane potential, cell cycle arrest at Sub G1 phase, and DNA fragmentation. Furthermore, niclosamide treatment resulted in abrogation of lipopolysaccharide-induced inflammatory cytokine levels in murine macrophages. Additionally, our results provided a preclinical rationale in imiquimod (IMQ)-induced BALB/c mouse model, where niclosamide diligently mitigated the IMQ-induced epidermal hyperplasia and inflammation by downregulating STAT3, p65 NF-κB, and NFATc-1 transcription factors along with Akt, Ki-67, and ICAM-1 protein expression.

Nanocrystals as Effective Delivery Systems of Poorly Water-soluble Natural Molecules

Natural products are an important source of therapeutically effective compounds throughout the world. Since ancient times, a huge amount of both plant extracts and isolated compounds have been largely employed in treatment and prevention of human disorders and, currently, more than 60% of the world's population trusts on plant medicaments as demonstrated by the increasing quantity of herbal therapeutics in the market. Unfortunately, several promising natural molecules for the treatment of the most diverse ailments are characterized by extremely unfavourable features, such as low water solubility and poor/irregular bioavailability, which hinder their clinical use. To overcome these limitations and to make herbal therapy more effective, different formulative approaches have been employed. Among the different strategies for increasing drug solubility, nanocrystals can be considered one of the most interesting and successful approaches. Drug nanocrystals are nanosized drug particles usually formulated as nanosuspensions, namely submicron dispersions in liquid media where surfactants, polymers, or a mixture of both act as stabilisers. In this review, we described the most significant results and progresses concerning drug nanocrystal formulations for the delivery of natural compounds with a significant pharmacological activity. The text is organized in nine sections, each focusing on a specific poorly water- soluble natural compound (apigenin, quercetin, rutin, curcumin, baicalin and baicalein, hesperetin and hesperidin, resveratrol, lutein, silybin). To foster the clinical translation of these natural nanomedicines, our opinion is that future research should pair the essential pharmacokinetic studies with carefully designed pre-clinical experiments, able to prove the formulation efficacy in relevant animal models in vivo.

Ginsenoside Rg1 abolish imiquimod-induced psoriasis-like dermatitis in BALB/c mice via downregulating NF-κB signaling pathway

This animal experiment was framed to evaluate the beneficial effect of ginsenoside Rg1 (GRg1) against imiquimod (IMQ)-induced psoriasis-like dermatitis model to reveal the underpinning mechanism. Fifty healthy BALB/c mice were divided into five groups as control, GRg1, IMQ induced, oral treatment of GRg1 (50 mg/kg), or dexamethasone (DXM; 10 mg/kg) in IMQ-induced mice. Treatment with GRg1 or DXM significantly mitigates (p < .01) psoriasis area severity index (PASI) score, skin thickness, lipid peroxidation, and inflammatory markers (IL-23, 22, 17A, 1β, and TNF-α). Moreover, administration of GRg1 or DXM considerably reversed the morphological changes induced by IMQ with improved (p < .01) antioxidant activity (SOD, CAT). In addition, a marked downregulation (p < .01) of protein expressions of pIκB and NF-κB p65 (NF-κB signaling pathway) were noted in GRg1 group. Collectively, GRg1 or DXM treatment significantly abolishes IMQ-induced psoriasis-like dermatitis by lowering PASI score, inflammation through downregulating NF-κB signaling pathway. PRACTICAL APPLICATIONS: This is the very first study to explore the efficacy of ginsenoside Rg1 (GRg1) against IMQ-induced psoriasis in the mice model to reveal the underpinning mechanism. The results clearly showed that GRg1 potent anti-psoriasis activity by lowering PASI score, inflammation through downregulating NF-κB signaling pathway. Hence, this study helps in the development of novel nutraceutical/functional food against psoriasis and thus could improve the quality of life in psoriasis patients. However, further clinical trials are needed to justify the above results before developing a commercial functional food using GRg1 against psoriasis.

The small molecule rhodomyrtone suppresses TNF-α and IL-17A-induced keratinocyte inflammatory responses: A potential new therapeutic for psoriasis

Psoriasis is a common skin disease pathogenically driven by TNF and IL-17A-induced epidermal hyperproliferation and inflammatory responses. The ongoing need for new therapeutic agents for psoriasis has highlighted medicinal plants as sources of phytochemicals useful for treating psoriatic disease. Rhodomyrtone, a bioactive phytochemical from Rhodomyrtus tomentosa, has well-established anti-proliferative activities. This study assessed the potential of rhodomyrtone for curtailing TNF/IL-17A-driven inflammation. Stimulating human skin organ cultures with TNF+IL-17A to model the skin inflammation in psoriasis, we found that rhodomyrtone significantly decreased inflammatory gene expression and the expression and secretion of inflammatory proteins, assessed by qRT-PCR, immunohistochemistry and ELISA assays respectively. RNA-seq analysis of monolayer primary keratinocytes treated with IL-17A/TNF showed that rhodomyrtone inhibited 724/1587 transcripts >2-fold altered by IL-17A/TNF (p<0.01), a number of which were confirmed at the mRNA and protein level. Suggesting that rhodomyrtone acts by modulating MAP kinase and NF-κB signaling pathways, rhodomyrtone inhibited TNF-induced ERK, JNK, p38, and NF-κBp65 phosphorylation. Finally, assessing the in vivo anti-inflammatory potential of rhodomyrtone, we examined its effects on imiquimod-induced skin inflammation in mice, finding rhodomyrtone reversed imiquimod-induced skin hyperplasia and epidermal thickening (p< 0.001). Taken together, these results suggest that rhodomyrtone may be useful in preventing or slowing the progression of inflammatory skin disease.

Imiquimod enhances the potency of an exogenous BM-DC based vaccine against mouse melanoma

Dendritic cell (DC) vaccine is a potent immunotherapeutic approach for cancer treatment, but the clinical efficacy needs to be improved. In this study, we evaluated the combinational effect of Toll-like receptor 7 (TLR7) agonist Imiquimod and BM-DC vaccine against mouse melanoma and explored the potential mechanisms. We found that topical application of Imiquimod cream caused skin inflammation and enhanced exogenous BM-DC homing to draining lymph nodes. Imiquimod treatment enhanced DC vaccine efficacy against B16-OVA melanoma. The combinational modality enhanced cytotoxicity of splenic lymphocyte to tumor cells and inhibited CD4⁺FOXP3⁺Treg cell production. TLR7 mRNA expression was confirmed in both MC/9 mast cells and DCs. MC/9 cells treated by R837 (soluble form of Imiquimod) enhanced CD80, CD86, MHC-II and CCR7 expression on DCs. R837 inhibited B16-OVA cell growth in vitro. Our findings suggest that Imiquimod can be used as a potent adjuvant in the formulation of a DC-based tumor fighting vaccine. The mechanisms underlying these effects of Imiquimod are related with enhanced DC homing to DLNs, inhibition of Treg's production, direct tumor cell toxicity and synergistic function with mast cell in enhancing DC activation.