Glabridin, an isoflavan from licorice root, ameliorates imiquimod-induced psoriasis-like inflammation of BALB/c mice

Topical application of magnolol ameliorates psoriasis-like dermatitis by inhibiting NLRP3/Caspase-1 pathway and regulating tryptophan metabolism

Psoriasis (PSO) is a common inflammatory skin disease caused by multiple factors. Magnolia officinalis is an important medicinal plant in China, with various values such as ecology, medicine, food, and daily chemicals. However, its diverse application potential has not been fully explored. Magnolol (MGO) is the main active compound of Magnolia officinalis with significant anti-inflammatory effect. To investigate the application potential of MGO in inflammatory skin disease, the effects and underlying mechanisms of topical MGO treating psoriasis were explored in this study. Network pharmacology and molecular docking firstly predicted that topical MGO may treat psoriasis by regulating pyroptosis pathway and acting on caspase-1 (CASP1). In vitro experiments then demonstrated that MGO could inhibit the level of inflammatory cytokines and the key protein expression of NOD-like receptor protein 3 (NLRP3)/Caspase-1 pathway in lipopolysaccharide (LPS)-stimulated phorbol 12-myristate 13-acetate (PMA)-differentiated THP-1 cells. Meanwhile, MGO could inhibit CuSO4-induced neutrophils migration in Tg (mpx:EGFP) zebrafish by suppressing inflammation and pyroptosis. This study further indicated that topical application of MGO ameliorated imiquimod (IMQ)-induced psoriasis-like dermatitis by reducing the release of inflammatory factors and decreasing the key protein expression of pyroptosis-related NLRP3/Caspase-1 pathway. Metabolomics analysis revealed that topical application of MGO could significantly regulate tryptophan metabolism and affect the level of tryptophan in skin lesions. Tryptophan could also regulate inflammation-related genes and inhibit pyroptosis-related NLRP3/Caspase-1 pathway in LPS-stimulated PMA-differentiated THP-1 cells. In conclusion, this study suggested that topical MGO may ameliorate psoriasis-like dermatitis by inhibiting NLRP3/Caspase-1 pathway and regulating tryptophan metabolism.

Bioactive substance contents and therapeutic potential for skin inflammation of an herbal gel containing Derris reticulata and Glycyrrhiza glabra

CONTEXT

Derris reticulata Craib. and Glycyrrhiza glabra L., of the Fabaceae, have been used as active components in Thai herbal formulas for the treatment of fever and skin diseases.

OBJECTIVE

To evaluate the physicochemical and pharmacological properties of the developed herbal gel formulation containing the combined extract from D. reticulata stem wood and G. glabra root (RGF).

MATERIALS AND METHODS

The potential of the herbal gel formulation containing RGF (8% w/w) as the active ingredient was studied by evaluating the anti-inflammatory, antioxidant, and anti-Staphylococcus aureus activities using quantitative reverse transcription-polymerase chain reaction assay, spectrophotometric method, and broth microdilution technique, respectively. The reference standards for the biological testing included Nω-nitro-L-arginine (L-NA), ascorbic acid, catechin, and penicillin G. The stability study of the RGF herbal gel was performed by a heating-cooling test (at 45 °C for 24 h and at 4 °C for 24 h/1 cycle; for 6 cycles), and the bioactive marker compounds in the herbal gel were investigated by the HPLC technique.

RESULTS

RGF showed promising pharmacological effects, particularly on its anti-inflammatory property (IC50 73.86 µg/mL), compared to L-NA (IC50 47.10 µg/mL). The RGF-containing gel demonstrated anti-inflammatory (IC50 3.59 mg/mL) and free radical scavenging effects (IC50 0.05-4.39 mg/mL), whereas it had no anti-S. aureus activity (MIC > 10 mg/mL). The active ingredient in the developed herbal gel significantly inhibited lipopolysaccharide-induced nitric oxide production by downregulating iNOS mRNA levels. The contents of the bioactive markers in the RGF gel (lupinifolin and glabridin) did not change significantly after stability testing.

DISCUSSION AND CONCLUSIONS

The RGF-containing gel has potential to be further developed as an herbal product for the treatment of skin inflammation.

Biochanin A Attenuates Psoriasiform Inflammation by Regulating Nrf2/HO-1 Pathway Activation and Attenuating Inflammatory Signalling

Psoriasis is a long-term inflammatory skin condition marked by an overabundance of keratinocytes and the release of pro-inflammatory cytokines in the outer layer of skin. For the comprehensive management of intermediate to advanced psoriasis, innovative biological treatments have been developed. Products for the superficial therapy of mild to moderate psoriasis are still necessary, though. Trifolium pratense contains the isoflavone biochanin A (BCA), which exhibits antiviral, antioxidant, anti-carcinogenic, and anti-inflammatory properties, and helps protect the integrity and function of the endothelium. Although investigations have not shown that BCA is effective in treating psoriasis, it has been shown to slow down the breakdown of the skin barrier by regulating keratinocyte growth. We sought to clarify the basic mechanisms behind BCA's impact on psoriasis in vitro and in vivo using experimental research via regulating Nrf2/HO-1 signaling pathway. By subjecting human primary keratinocytes to psoriasis-related cytokines, psoriasis-like keratinocytes were produced. The CCK8 test was used in this investigation to assess cell viability. BCA reduced keratinocyte growth and inflammatory cascade stimulation produced by TNF-α and IL-6, according to in vitro investigations conducted on HaCaT cells. The in vivo findings showed that six days of BCA therapy significantly decreased the skin, hematological indicators, levels of NO, TBARS, histopathological, and pro-inflammatory factors of COX-2, iNOS, NF-κB pathway. It additionally influenced the protein content of pro-inflammatory cytokines such as IL-17, IL-23, IL-1β in the epidermis along with IL-6, TNF-α among the epidermis and serum. In addition, in contrast to the IMQ group, BCA improved the skin's level of Nrf2/HO-1 protein, anti-inflammatory cytokine IL-10, and antioxidant indicators like SOD, CAT, GST, GSH, GR, and Vit-C. Ultimately, our research shows that BCA was effective in treating psoriasis in pre-clinical animal models by activating the Nrf2/HO-1 pathway, leading to an increase in antioxidant and anti-inflammatory markers.

Liquiritin exerts psoriasis therapy and prevention by regulating the YY1/RBP3 axis

BACKGROUND

Psoriasis (PSO) poses a global health threat. The current research challenge in PSO is relapse. Liquiritin (LIQ), a major active compound from Glycyrrhiza inflata Batalin, has multiple pharmacological properties, including anti-inflammatory and anti-proliferative. Nonetheless, the precise mechanisms underlying LIQ's therapeutic actions in PSO and prevention abilities remain elusive.

PURPOSE

The present study aimed to delve into the potential to treat and prevent PSO and the mechanism of LIQ.

METHODS

The anti-inflammatory and anti-proliferative effects of LIQ were studied in vitro with the HaCaT cell line. Then, Transcriptional analysis and bioinformatic analysis were used to determine the internal associations of the target set. Subsequently, functional experiment, luciferase report assay, ChIP-PCR, and immunohistochemical validation of clinical samples were performed to investigate the mechanism of LIQ. Finally, the anti-psoriatic effects and prevention abilities of LIQ were verified in vivo with imiquimod (IMQ)-induced PSO-like mouse models.

RESULTS

Here, we identified differentially expressed genes in LIQ-stimulated HaCaT cells and Retinol-Binding Protein 3 (RBP3) as the core target, whereas YY1 was a predicted upstream transcription factor of RBP3. The YY1/RBP3 axis was obviously altered after administering LIQ at optimal doses of 20 μM in vitro and 100 µg/ml in vivo. LIQ can significantly inhibit the progression of PSO in vivo. Notably, LIQ also prevented the relapse of psoriatic lesions induced by the second round of low-dose IMQ. Mechanistically, we observed that LIQ could increase the promotion of YY1 for RBP3 by enhancing the binding affinity between them.

CONCLUSION

These findings revealed that the YY1/RBP3 axis is a potential psoriatic target, and LIQ is a promising and innovative therapeutic candidate for the treatment and prevention of PSO.

Flavonoid compounds and their synergistic effects: Promising approaches for the prevention and treatment of psoriasis with emphasis on keratinocytes - A systematic and mechanistic review

Psoriasis, a chronic autoimmune skin disorder, causes rapid and excessive skin cell growth due to immune system dysfunction. Numerous studies have shown that flavonoids have anti-psoriatic effects by modulating various molecular mechanisms involved in inflammation, cytokine production, keratinocyte proliferation, and more. This study reviewed experimental data reported in scientific literature and used network analysis to identify the potential biological roles of flavonoids' targets in treating psoriasis. 947 records from Web of Sciences, ScienceDirect database, Scopus, PubMed, and Cochrane library were reviewed without limitations until June 26, 2023. 66 articles were included in the systematic review. The ten genes with the highest scores, including interleukin (IL)-10, IL-12A, IL-1β, IL-6, Tumor necrosis factor-α (TNF-α), Janus kinase 2 (JAK 2), Jun N-terminal kinase (JUN), Proto-oncogene tyrosine-protein kinase Src (SRC), Phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA), and Signal transducer and activator of transcription 3 (STAT3), were identified as the hub genes. KEGG pathway analysis identified connections related to inflammation and autoimmune responses, which are key characteristics of psoriasis. IL-6, STAT3, and JUN's presence in both hub and enrichment genes suggests their important role in flavonoid's effect on psoriasis. This comprehensive study highlights how flavonoids can target biological processes in psoriasis, especially when combined for enhanced effectiveness.

Promising strategies in natural products treatments of psoriasis-update

Psoriasis is a chronic, relapsing, inflammatory skin disease and has been increasing year by year. It is linked to other serious illnesses, such as psoriatic arthritis, cardiometabolic syndrome, and depression, resulting in a notable decrease in the quality of life for patients. Existing therapies merely alleviate symptoms, rather than providing a cure. An in-depth under-standing of the pathogenesis of psoriasis is helpful to discover new therapeutic targets and develop effective novel therapeutic agents, so it has important clinical significance. This article reviews the new progress in the study of pathogenesis and natural products of psoriasis in recent years. These natural products were summarized, mainly classified as terpenoids, polyphenols and alkaloids. However, the translation of experimental results to the clinic takes a long way to go.

Exploring the Therapeutic Potential of Natural Compounds in Psoriasis and Their Inclusion in Nanotechnological Systems

Psoriasis is a chronic inflammatory disease that affects around 2-3% of the world's population. The treatment for this autoimmune disease still remains centered around conventional methods using synthetic substances, even though more recent advancements focus on biological therapies. Given the numerous side effects of such treatments, current research involves plant extracts and constituents that could prove useful in treating psoriasis. The aim of this narrative review is to highlight the most known representatives belonging to classes of natural compounds such as polyphenols (e.g., astilbin, curcumin, hesperidin, luteolin, proanthocyanidins, and resveratrol), alkaloids (e.g., berberine, capsaicin, and colchicine), coumarins (psoralen and 8-methoxypsoralen), and terpenoids (e.g., celastrol, centelloids, and ursolic acid), along with plants used in traditional medicine that could present therapeutic potential in psoriasis. The paper also provides an overview of these compounds' mechanisms of action and current inclusion in clinical studies, as well as an investigation into their potential incorporation in various nanotechnological systems, such as lipid-based nanocarriers or polymeric nanomaterials, that may optimize their efficacy during treatment.

Immunomodulatory effect of glabridin in ovalbumin induced allergic asthma and its comparison with methylprednisolone in a preclinical rodent model

Glabridin, a polyphenolic flavonoid derived from Glycyrrhiza glabra (licorice) roots, has shown anti-inflammatory and antioxidant properties. The current study sought to investigate glabridin's immunomodulatory effect in ovalbumin induced allergic asthma. Healthy male Wistar rats were divided into five groups. Group I served as a control group. Asthma was induced in groups II- IV. Groups III and IV were treated with glabridin (40 mg/kg) and methylprednisolone (15 mg/kg), respectively. Inflammatory cells counts were determined in blood and bronchoalveolar lavage fluid (BALF). Serum IgE levels and levels of catalase, superoxide dismutase and glutathione peroxidase in lung homogenate were measured. The levels of mRNA expression of pro-inflammatory, anti-inflammatory and oxidative stress markers were analysed. Delayed type hypersensitivity (DTH) and acute toxicity of glabridin were also checked. Glabridin significantly decreased inflammatory cells in the blood and BALF. It increased the concentration of antioxidant enzymes catalase, superoxide dismutase and glutathione peroxidase. Glabridin markedly decreased serum IgE levels and DTH when compared to asthmatic rats. It significantly alleviated the expression of TNF-α, IL-4, IL-5, CXCL1, iNOS, and NF-κB. Administering 10 times the therapeutic dose of glabridin did not show any signs of acute toxicity. Findings suggest that glabridin has the potential to ameliorate allergic asthma and its effects are comparable to those of methylprednisolone. The immunomodulatory effect of glabridin might be contributed by the suppression of pro-inflammatory cytokines, oxidative stress markers, IgE antibodies, and elevation of antioxidant enzymes, suggesting future study and clinical trials to propose it as a candidate to treat allergic asthma.

Overexpression and potential roles of midkine via regulation of vascular endothelial growth factor A in psoriasis

Midkine plays a critical role in angiogenesis by regulating the vascular endothelial growth factor (VEGF) signalling pathway, which is known to be associated with psoriasis pathogenesis. However, research on midkine-psoriasis relationship remains limited. The objective of this study was to detect midkine expression in psoriasis and investigate its potential role in the disease. Midkine expression was measured using immunohistochemistry and ELISA. Effects of midkine on HaCaT cell proliferation, VEGF-A production and signalling pathways were assessed using CCK8, RT-PCR and WB. Scratch and in vitro tube formation tests were used to evaluate the effects of HaCaT-cell-activated midkine on the migration and tube formation of human dermal microvascular endothelial cells. Murine psoriasiform models were injected with midkine recombinant protein and midkine monoclonal antibody to investigate skin lesions, tissue sections and dermal microvessel density. Levels of midkine significantly increased in both lesions and serum of patients with psoriasis. Serum expression of midkine decreased after treatment and a positive correlation was found between midkine and disease severity. Midkine promoted HaCaT cell proliferation and VEGF-A production. The Notch2/HES1/JAK2-STAT5A pathway expression increased after midkine treatment of HaCaT cells. The supernatant of HaCaT cells treated with midkine promoted HMEC-1 migration and angiogenesis in vitro. Recombinant midkine protein exacerbated psoriasiform lesions with increased expressions of VEGF-A and microvessel density, while midkine monoclonal antibody alleviated psoriasis lesions. Midkine may have a significant impact on psoriasis angiogenesis by regulating VEGF-A expression through the Notch2/HES1/JAK2-STAT5A pathway, highlighting a potential therapeutic target for psoriasis treatment.

Nano transdermal system combining mitochondria-targeting cerium oxide nanoparticles with all-trans retinoic acid for psoriasis

Psoriasis is an inflammatory skin disease that is intricately linked to oxidative stress. Antioxidation and inhibition of abnormal proliferation of keratinocytes are pivotal strategies for psoriasis. Delivering drugs with these effects to the site of skin lesions is a challenge that needs to be solved. Herein, we reported a nanotransdermal delivery system composed of all-trans retinoic acid (TRA), triphenylphosphine (TPP)-modified cerium oxide (CeO2) nanoparticles, flexible nanoliposomes and gels (TCeO2-TRA-FNL-Gel). The results revealed that TCeO2 synthesized by the anti-micelle method, with a size of approximately 5 nm, possessed excellent mitochondrial targeting ability and valence conversion capability related to scavenging reactive oxygen species (ROS). TCeO2-TRA-FNL prepared by the film dispersion method, with a size of approximately 70 nm, showed high drug encapsulation efficiency (>96%). TCeO2-TRA-FNL-Gel further showed sustained drug release behaviors, great transdermal permeation ability, and greater skin retention than the free TRA. The results of in vitro EGF-induced and H2O2-induced models suggested that TCeO2-TRA-FNL effectively reduced the level of inflammation and alleviated oxidative stress in HaCat cells. The results of in vivo imiquimod (IMQ)-induced model indicated that TCeO2-TRA-FNL-Gel could greatly alleviate the psoriasis symptoms. In summary, the transdermal drug delivery system designed in this study has shown excellent therapeutic effects on psoriasis and is prospective for the safe and accurate therapy of psoriasis.

Glabridin Ameliorates Alcohol-Caused Liver Damage by Reducing Oxidative Stress and Inflammation via p38 MAPK/Nrf2/NF-κB Pathway

Licorice is a traditional and versatile herbal medicine and food. Glabridin (Gla) is a kind of isoflavone extracted from the licorice root, which has anti-obesity, anti-atherosclerotic, and antioxidative effects. Alcoholic liver disease (ALD) is a widespread liver disease induced by chronic alcohol consumption. However, studies demonstrating the effect of Gla on ALD are rare. The research explored the positive effect of Gla in C57BL/6J mice fed by the Lieber-DeCarli ethanol mice diet and HepG2 cells treated with ethanol. Gla alleviated ethanol-induced liver injury, including reducing liver vacuolation and lipid accumulation. The serum levels of inflammatory cytokines were decreased in the Gla-treated mice. The reactive oxygen species and apoptosis levels were attenuated and antioxidant enzyme activity levels were restored in ethanol-induced mice by Gla treatment. In vitro, Gla reduced ethanol-induced cytotoxicity, nuclear factor kappa B (NF-κB) nuclear translocation, and enhanced nuclear factor (erythroid-derived 2)-like 2 (Nrf2) nuclear translocation. Anisomycin (an agonist of p38 MAPK) eliminated the positive role of Gla on ethanol-caused oxidative stress and inflammation. On the whole, Gla can alleviate alcoholic liver damage via the p38 MAPK/Nrf2/NF-κB pathway and may be used as a novel health product or drug to potentially alleviate ALD.

Comprehensive Evaluation of Metabolism and the Contribution of the Hepatic First-Pass Effect in the Bioavailability of Glabridin in Rats

Glabridin is a bioactive isoflavan, which has a wide range of biological properties and is widely used in the market of health products and dietary supplements. However, the transformation pathway of glabridin in vivo is unclear, and the bioavailability is controversial among different studies. Therefore, a new HPLC-Q-TOF method was developed to analyze and identify the prototype and metabolites of glabridin in rats. A total of 63 compounds were identified, including hydroxylation, demethylation, acetylation, demethylation to carboxylation, glucuronidation, and sulfate conjugation, and 43 of which were new metabolites that had not been reported. Additionally, our study verified that the oral bioavailability of glabridin was 6.63 ± 2.29% in rats. Furthermore, we found that the hepatic first-pass effect was 62.12 ± 15.7% for glabridin. These results indicated that a high hepatic first-pass effect and extensive metabolism of glabridin in vivo may lead to its limited oral bioavailability.

Review on the Diverse Biological Effects of Glabridin

Glabridin is a prenylated isoflavan from the roots of Glycyrrhiza glabra Linne and has posed great impact on the areas of drug development and medicine, due to various biological properties such as anti-inflammation, anti-oxidation, anti-tumor, anti-microorganism, bone protection, cardiovascular protection, neuroprotection, hepatoprotection, anti-obesity, and anti-diabetes. Many signaling pathways, including NF-κB, MAPK, Wnt/β-catenin, ERα/SRC-1, PI3K/AKT, and AMPK, have been implicated in the regulatory activities of glabridin. Interestingly, glabridin has been considered as an inhibitor of tyrosinase, P-glycoprotein (P-gp), and CYP2E1 and an activator of peroxisome proliferator-activated receptor γ (PPARγ), although their molecular regulating mechanisms still need further investigation. However, poor water solubility and low bioavailability have greatly limited the clinical applications of glabridin. Hopefully, several effective strategies, such as nanoemulsions, microneedles, and smartPearls formulation, have been developed for improvement.

Glabridin Plays Dual Action to Augment the Efficacy and Attenuate the Hepatotoxicity of Methotrexate in Arthritic Rats

Glabridin is chemically an isoflavane class of natural phenols and is found mainly in the roots of Glycyrrhiza glabra. It has several beneficial pharmacological actions for the management of inflammatory disorders as well as can counteract drug-induced toxic effects. On the other hand, methotrexate (MTX) is the first-line disease-modifying antirheumatic drug for the treatment of rheumatoid arthritis. However, its treatment is associated with major side effects like hepatotoxicity. In the quest to explore a suitable combination therapy that can improve the efficacy and reduce the hepatotoxicity of MTX, we hypothesized that glabridin might serve the purpose for which there is no literature precedent to date. We explored the antiarthritic efficacy of MTX in the presence or the absence of glabridin using Mycobacterium-induced arthritic model in rats. The results of reduction in paw swelling, inhibition of serum cytokines (TNF-α, IL-6, and IL-1β), and improvement in the bone joints from radiological and histopathological findings suggest that glabridin can substantially augment the antiarthritic efficacy of MTX. Further, results of concomitant glabridin treatment with MTX in the experimental time frame demonstrate that glabridin could considerably prevent the MTX-induced hepatic alteration in serum biochemical markers (SGPT and SGOT) and oxidative stress markers (malondialdehyde (MDA) and glutathione reduced (GSH)). Moreover, glabridin showed a marked effect in impeding the regulation of NF-κB/IκBα and Nrf2/Keap1 pathways in the hepatic tissues. The results of simultaneous administration of glabridin with MTX in the rat model indicate that glabridin had no pronounced effect of causing severe alteration in the pharmacokinetic behavior of MTX. In summary, glabridin can significantly potentiate the antiarthritic efficacy of MTX and can also minimize its hepatotoxicity via the inhibition of inflammation and oxidative stress. Further research should be performed to develop glabridin as a phytotherapeutics for the improved efficacy and better tolerability of MTX at the reduced dose level of MTX.

Molecular mechanisms of Biyu decoction as treatment for psoriasis: A network pharmacology and molecular docking study

BACKGROUND

The therapeutic effects of a combination of Chinese medicines called Biyu decoction have been clinically verified, although its molecular targets in psoriasis remain unknown.

AIM

To explore the molecular mechanisms of Biyu decoction for psoriasis treatment.

METHODS

In this network pharmacology and molecular docking study, the Traditional Chinese Medicine Systems Pharmacology database was searched for Biyu decoction active ingredients. GeneCards, Online Mendelian Inheritance in Man, PharmGkb, Therapeutic Target Database, and DrugBank databases were searched for psoriasis-related genes. The genes targeted by the decoction’s active ingredient and disease genes were intersected to obtain predictive targets of the drug during psoriasis treatment. Cytoscape 3.8.0 was used to construct a drug component/ target disease network. The The functional protein association networks database and Cytoscape were used to construct a protein-protein interaction network and streamline the core network. The Gene Ontology and Kyoto Encyclopedia of Genes and Genomes were used for pathway enrichment analysis. Molecular docking technology was used to verify the drug component/target disease network.

RESULTS

We screened 117 major active ingredients, including quercetin, kaempferol, naringenin, and acetyl-shikonin, and identified 213 gene targets, such as MAPK3, JUN, FOS, MYC, MAPK8, STAT3, and NFKBIA. Using a molecular docking analysis, the main active ingredients demonstrated good binding to the core targets. The Gene Ontology analysis showed that these ingredients were significantly associated with biological activities, such as transcription factor DNA binding, RNA polymerase II-specific DNA binding of transcription factors, and cytokine receptor binding; responses to lipopolysaccharides, molecules of bacterial origin, and oxidative stress; and were mainly distributed in membrane rafts, microdomains, and regions. The Kyoto Encyclopedia of Genes and Genomes analysis showed that decoction ingredients act on Th17 cell differentiation, tumor necrosis factor and mitogen-activated protein signaling pathways, the interleukin-17 signaling pathway, and the PI3K-Akt signaling pathway.

CONCLUSION

Biyu decoction may be effective against psoriasis through multi-component, multi-target, and multi-channel synergy.

Glabrol impurity exacerbates glabridin toxicity in zebrafish embryos by increasing myofibril disorganization

ETHNOPHARMACOLOGICAL RELEVANCE

Glabridin, extracted from Glycyrrhiza glabra L., is widely used for the treatment of hyperpigmentation because of its anti-inflammatory and antioxidant activities and its ability to inhibit melanin synthesis. This led to the strict regulation of its quality and safety. However, traditional quality control methods used for plant extracts cannot reflect the product quality owing to multiple unknown impurities, which necessitates the further analysis of impurities.

AIM OF THE STUDY

The study identified the toxic impurities of glabridin and their toxicological mechanism.

MATERIALS AND METHODS

In total, 10 glabridin samples from different sources were quantified using high-performance liquid chromatography. Sample toxicities were evaluated using zebrafish and cell models. To identify impurities, samples with different toxicity were analyzed by ultra-high-performance liquid chromatography coupled with quadrupole-Orbitrap mass spectrometry. The toxicity of related impurities was verified in the zebrafish model. Phalloidin stain was used to evaluate subtle changes in myofibril alignment.

RESULTS

Although glabridin content in the samples was similar, there were significant differences in toxicity. The results were verified using four different mammalian cell lines. Higher contents of glabrone and glabrol were identified in the sample with the highest toxicity. In the zebrafish model, the addition of glabrol reduced the LC₅₀ of glabridin to 9.224, 6.229, and 5.370 μM at 48, 72, and 96 h post-fertilization, respectively, whereas glabrone did not have any toxic effect. Phalloidin staining indicated that a glabrol impurity exacerbates the myotoxicity of glabridin in zebrafish embryos.

CONCLUSION

Glabrol, but not glabrone, was identified as a key impurity that increased glabridin toxicity. This finding indicates that controlling glabrol content is necessary during glabridin product production.

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.

Design and synthesis of the 4H-chromenone derivatives against psoriasis

On basis of Quercetin moiety, two series of 20 new compounds were designed and synthesized accordingly in this study, and their anti-inflammatory activities in vitro and in vivo were evaluated. At last, compound 8A2: 3- (1- (2- (4- (5-bromo-2-chlorobenzoyl) piperazin-1-yl) ethyl)-1H-1,2,3-triazol-4-yl) methoxy)-5,7-dimethoxy-2-(3,4,5-trimethoxyphenyl)-4H-chromen-4-one with low toxicity was found the best one for inhibiting of NO. Meanwhile, this compound could significantly inhibit the expression of IL-6 (Interleukin-6), TNF-α (Tumor necrosis factor-α) and IL-17 (Interleukin-17), and also significantly down-regulate IL-17 mRNA psoriasis model in vitro. Further studies were performed to establish mouse psoriasis model induced by Imiquimod (IMQ), and the preliminary mechanism indicated that compound 8A2 may alleviate mouse psoriasis through obstructed the JAK1/2-STAT1/3 pathway. This study should be provide a basis for further study of effective treatment of psoriasis.

Pharmacological Effects and Underlying Mechanisms of Licorice-Derived Flavonoids

Glycyrrhizae Radix et Rhizoma is the most frequently prescribed natural medicine in China and has been used for more than 2,000 years. The flavonoids of licorice have garnered considerable attention in recent decades due to their structural diversity and myriad pharmacological effects, especially as novel therapeutic agents against inflammation and cancer. Although many articles have been published to summarize different pharmacological activities of licorice in recent years, the systematic summary for flavonoid components is not comprehensive. Therefore, in this review, we summarized the pharmacological and mechanistic data from recent researches on licorice flavonoids and their bioactive components.

The role of Glabridin in antifungal and anti-inflammation effects in Aspergillus fumigatus keratitis

PURPOSE

To investigate the effect of Glabridin (GLD) in Aspergillus fumigatus keratitis and its associated mechanisms.

METHODS

Aspergillus fumigatus (A. fumigatus) conidia was inoculated in 96-well plate, and minimal inhibitory concentration (MIC) and biofilm formation ability were evaluated after GLD treatment. Spore adhesion ability was evaluated in conidia infected human corneal epithelial cells (HCECs). Keratitis mouse model was created by corneal intrastromal injection with A. fumigatus conidia, and GLD treatment started at the day after infection. The number of fungal colonies was calculated by plate count, and degree of corneal inflammation was assessed by clinical score. Flow cytometry, myeloperoxidase (MPO), and immunofluorescence staining (IFS) experiments were used to assess neutrophil infiltrations. PCR, ELISA and Western blot were conducted to determine levels of TLR4, Dectin-1 as well as downstream inflammatory factors.

RESULTS

GLD treatment suppressed the proliferation, biofilm formation abilities and adhesive capability of A. fumigatus. In mice upon A. fumigatus infection, treatment of GLD showed significantly decreased severity of corneal inflammation, reduced number of A. fumigatus in cornea, and suppressed neutrophil infiltration in cornea. GLD treatment obviously inhibited mRNA and protein levels of Dectin-1, TLR4 and proinflammatory mediators such as IL-1β, HMGB1, and TNF-α in mice corneas compared to the control group.

CONCLUSION

GLD has antifungal and anti-inflammatory effects in fungal keratitis through suppressing A. fumigatus proliferation and alleviating neutrophil infiltration, and repressing the expression of TLR4, Dectin-1 and proinflammatory mediators.

Impact of isoflavone genistein on psoriasis in in vivo and in vitro investigations

Genistein is applied worldwide as an alternative medicament for psoriasis (Ps) because of its anti-inflammatory activity and perceived beneficial impact on the skin. Hereby, we report our in vivo and in vitro investigations to supplement scientific research in this area. The reduction of clinical and biochemical scores in mild to moderate Ps patients taking genistein, its safety, good tolerability with no serious adverse events or discontinuations of treatment, no dose-limiting toxicities, negligible changes in pharmacodynamic parameters and remarkable serum interleukin level alterations were documented in this study. A certain regression of the Ps phenotype was visible, based on photo-documented Ps lesion evaluation. Through in vitro experiments, we found that genistein reduced IL-17A and TNF-α induced MAPK, NF-κB, and PI3K activation in normal human epidermal keratinocytes. Moreover, at the mRNA level of genes associated with the early inflammatory response characteristic for Ps (CAMP, CCL20, DEFB4A, PIK3CA, S100A7, and S100A9) and key cellular signalling (MTORC1 and TFEB), we showed that this isoflavone attenuated the increased response of IL-17A- and TNF-α-related pathways. This allows us to conclude that genistein is a good candidate for Ps treatment, being attractive for co-pharmacotherapy with other drugs.

Current evidence to support the therapeutic potential of flavonoids in oxidative stress-related dermatoses

BACKGROUND

Skin, as a crucial external defense organ, is more vulnerable to oxidative stress (OS) insult, reactive oxygen species (ROS)-mediated OS in particular. OS results from a redox imbalance caused by various extrinsic stimuli and occurs once the oxidants production overwhelming the antioxidants capacity, through mediating in DNA damage, lipid peroxidation (LPO), protein oxidation and a serial of signaling pathways activation/inactivation, thereby offering favorable conditions for the occurrence and development of numerous diseases especially some dermatoses, e.g. psoriasis, vitiligo, skin photodamage, skin cancer, systemic sclerosis (SSc), chloasma, atopic dermatitis (AD), pemphigus, etc. Targeting OS molecular mechanism, a variety of anti-OS agents emerge, in which flavonoids, natural plant extracts, stand out.

OBJECTIVES

To discuss the possible mechanisms of OS mediating in dermatoses and summarize the properties of flavonoids as well as their applications in OS-related skin disorders.

METHODS

Published papers on flavonoids and OS-related skin diseases were collected and reviewed via database searching on PubMed, MEDLINE and Embase, etc.

RESULTS

It has been confirmed that flavonoids, belonging to polyphenols, are a class of plant secondary metabolites widely distributed in various plants and possess diverse bioactivities especially their potent antioxidant capacity. Moreover, flavonoids benefit to suppress OS via eliminating free radicals and mediating the corresponding signals, further excellently working in the prevention and management of OS-related skin diseases.

CONCLUSION

Flavonoids have the potential therapeutic effects on oxidative stress-related dermatoses. However, more studies on specific mechanism as well as the dosage of flavonoids are needed in future.

Galangin ameliorates Imiquimod-Induced psoriasis-like skin inflammation in BALB/c mice via down regulating NF-κB and activation of Nrf2 signaling pathways

Psoriasis is a most common chronic autoimmune-arbitrated cutaneous inflammatory skin disorder by unclear pathogenesis. In this current study we demonstrated the effect of galangin (GAL) on imiquimod (IMQ)-induced psoriasis-like skin inflammation and decipher its possible protective mechanism which has not been investigated. The in vivo results revealed that GAL at 1% w/w and 2% w/w for six consecutive days markedly reduced IMQ-induced PASI scoring, skin, ear thickness, hematological markers, levels of nitrites, TBARS, MPO, histopathological, as well modulated the protein levels of pro-inflammatory mediators of COX-2, iNOS, NF-κB pathway and pro-inflammatory cytokines IL-17, IL-23, IL-1β in the skin and also IL-6, TNF-α in both skin and serum. Besides, GAL restored the levels of antioxidants markers such as SOD, CAT, GST, GSH, GR and Vit-C, anti-inflammatory cytokine of IL-10, and the protein levels of Nrf2/HO-1 in the skin compared to the IMQ group. Finally, our study demonstrates that GAL exerted its protective effect by up-regulating the anti-inflammatory and the antioxidant markers against psoriasis pre-clinical models indicating its potency for treating psoriasis in humans.

Triptolide analog LLDT-8 ameliorates psoriasis-like dermatitis in BALB/c mice via suppressing the IL-36α signaling pathway

Triptolide has shown a good immunosuppressive effect on autoimmune diseases. However, the toxicity limited its widely clinical practice. In this study, we investigated the effects and underlying mechanisms of (5R)-5-hydroxytriptolide (LLDT-8), a novel triptolide derivative, on a murine psoriasis-like dermatitis model and related cell lines. Here, we showed that LLDT-8 significantly attenuated symptoms of psoriasis-like dermatitis induced by imiquimod (IMQ, a TLR7 agonist) by reducing the psoriasis area and severity index (PASI) score and inflammatory parameters. The action of LLDT-8 was involved in down-regulated interleukin (IL)-36α expression and blocked IL-36α pathway by LC-MS-based label-free quantitative (LFQ) proteomic approach and further experiments. Meanwhile, we observed that LLDT-8 significantly inhibited the expression of IL-36α in R837-treated bone marrow-derived dendritic cells (BMDCs). In conclusion, LLDT-8 notably alleviated IMQ-induced psoriasis-like skin inflammation via suppressing the IL-36α signaling pathway, suggesting LLDT-8 might be a potential drug for the treatment of psoriasis.

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.

Elaeagnus L gum polysaccharides alleviate the impairment of barrier function in the dry skin model mice

BACKGROUND

Dry skin is a common skin condition caused by reduction of water-holding capacity, which is regulated by skin barrier function. Dry skin can also be a symptom that indicates a more serious diagnosis. There are a number of moisturizers on the market, which play an important role in dermatologic and cosmetic therapies. However, the demand for these products with good and therapeutic efficiency is still growing.

AIMS

It remains necessary to investigate the effects of Elaeagnus L gum polysaccharides (EAP), which are prepared from gum of Elaeagnus angustifolia L. on the epidermal permeability barrier function and their possible underlying mechanisms.

PATIENTS/METHODS

EAP were purified, analyzed, and tested on human keratinocyte cell line (HaCaT) and then on the skin in vivo to evaluate their antiinflammatory activities and their impacts on impaired skin barrier function.

RESULTS

Histological analyses revealed that topical administration with EAP effectively attenuated dryness-like skin condition, including less percutaneous water loss rate, less infiltrate inflammation cells, and less epidermal thickening. Moreover, EAP inhibited the production of various inflammatory mediators and increased AQP-3, FLG, and LOR expression.

CONCLUSION

Our results indicated that EAP enhances epidermal permeability barrier function, and they can be used as a promising adjuvant agent in skin care cosmetics and in treating some skin disorders characterized by cutaneous inflammation and abnormal barrier function.

Glabridin attenuates airway inflammation and hyperresponsiveness in a mice model of ovalbumin-induced asthma

Asthma is an inflammatory disease of the airways of the lungs, which is characterized by airflow obstruction and bronchospasms. Glabridin is a major flavonoid, especially found in root of Glycyrrhiza glabra, and has several pharmacological activities, including antioxidant and anti-inflammatory effects. The anti-asthmatic effect and possible mechanism of glabridin, however, have not been revealed so far. The aim of this study is to investigate the effects and possible mechanisms of glabridin against ovalbumin (OVA)-induced airway hyperresponsiveness (AHR) and inflammation in mice. In male BALB/c mice, asthma was induced by intraperitoneal (i.p) injection of OVA mixed with 2 mg aluminium hydroxide on days 0, 14 and boosted with OVA aerosol challenge on days 21, 22, and 23. Mice were either treated with dexamethasone (i.p, 1 mg/kg) or glabridin (10, 20, and 30 mg/kg) from days 18-23. Pulmonary function parameters such as peak inspiratory flow, peak expiratory flow, tidal volume, expiratory volume, the frequency of breathing, enhanced pause values were evaluated by using whole-body plethysmography. Measurements were performed at baseline and following methacholine (50 mg/mL) challenges. In addition, white blood cells (WBC) count, total protein, and IgE levels were measured in bronchial alveolar lavage fluid (BALF), lung, and serum, respectively. Glabridin (20 or 30 mg/kg) significantly attenuated (p < 0.05) OVA-induced alteration in respiratory parameters. Elevated counts of total WBC, differential WBC (neutrophils, lymphocytes, monocytes, and eosinophils) in BALF and the total protein in lungs and BALF were significantly decreased (p < 0.05) by glabridin (20 or 30 mg/kg). It also significantly attenuated the increased serum IgE levels (p < 0.05). As glabridin reduces the level of serum IgE, the total protein and the count of WBC and improves respiratory function, it may be a novel therapeutic agent in asthma.

Cyclodextrin-Modified CeO2 Nanoparticles as a Multifunctional Nanozyme for Combinational Therapy of Psoriasis

Purpose

Reactive oxygen species (ROS)-induced oxidative stress plays a key role in the pathogenesis and progression of psoriasis by causing inflammation. Antioxidative strategies eradicating ROS may serve as effective and easy treatment options for psoriasis, while nanozymes with intrinsic antioxidant enzyme-like activity have not been explored for psoriasis treatment. The aim of this study is to fabricate β-cyclodextrins (β-CDs)-modified ceria nanoparticles (β-CDs/CeO₂ NPs) with drug-loaded and multimimic-enzyme activities for combinational psoriasis therapy.

Methods

The β-CDs/CeO₂ NPs were synthesized by a hydrothermal method using unmodified β-CDs as a protecting agent. The structure, size and morphology were analyzed by dynamic light scattering, transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared (FTIR) spectroscopy. Considering the superoxide dismutase (SOD)- and catalase-mimetic activities, the in vitro antioxidant activity of the β-CDs/CeO2 NPs was investigated. After dithranol (DIT) was loaded, the drug-loading capacity and release profile were determined by UV-visible light spectrophotometer and high-performance liquid chromatography. The anti-psoriatic efficacy was studied in the imiquimod (IMQ)-induced mouse model on the basis of morphological evaluation, psoriasis area and severity index calculation (PASI), and inflammatory cytokine expression.

Results

The average particle size of the blank β-CDs/CeO₂ NPs was 60.89±0.32 nm with a polydispersity index (PDI) of 0.12, whereas that of the DIT-loaded NPs was 79.38±1.06 nm with a PDI of 0.27. TEM results showed the as-prepared NPs formed a uniform quasi-spherical shape with low polydispersity. XPS indicates synthesized NPs have a mixed Ce³⁺/Ce⁴⁺ valence state. FTIR spectroscopy confirmed the presence of β-CDs and DIT in the NPs. Inhibition of superoxide anion rate by NPs could be reached to 79.4% in the presence of 200 µg/mL, and elimination of H₂O₂ efficiency reached about 50% in the presence of 40 µg/mL, demonstrating excellent superoxide dismutase- and catalase-mimicking activities, thereby providing remarkable cryoprotection against ROS-mediated damage. Furthermore, β-CDs on the surface endowed the NPs with drug-loading function via host–guest interactions. The entrapment efficiency and drug loading of DIT are 94.7% and 3.48%, respectively. The in vitro drug release curves revealed a suitable release capability of DIT@β-CDs/CeO₂ NPs under physiological conditions. In IMQ-induced psoriatic model, the DIT@β-CDs/CeO₂ NPs exhibited excellent therapeutic effect.

Conclusion

This study may pave the way for the application of nanozyme β-CDs/CeO₂ NPs as a powerful tool for psoriasis therapy.

Emerging Roles of Redox-Mediated Angiogenesis and Oxidative Stress in Dermatoses

Angiogenesis is the process of new vessel formation, which sprouts from preexisting vessels. This process is highly complex and primarily involves several key steps, including stimulation of endothelial cells by growth factors, degradation of the extracellular matrix by proteolytic enzymes, migration and proliferation of endothelial cells, and capillary tube formation. Currently, it is considered that multiple cytokines play a vital role in this process, which consist of proangiogenic factors (e.g., vascular endothelial growth factor, fibroblast growth factors, and angiopoietins) and antiangiogenic factors (e.g., endostatin, thrombospondin, and angiostatin). Angiogenesis is essential for most physiological events, such as body growth and development, tissue repair, and wound healing. However, uncontrolled neovascularization may contribute to angiogenic disorders. In physiological conditions, the above promoters and inhibitors function in a coordinated way to induce and sustain angiogenesis within a limited period of time. Conversely, the imbalance between proangiogenic and antiangiogenic factors could cause pathological angiogenesis and trigger several diseases. With insights into the molecular mechanisms of angiogenesis, increasing reports have shown that a close relationship exists between angiogenesis and oxidative stress (OS) in both physiological and pathological conditions. OS, an imbalance between prooxidant and antioxidant systems, is a cause and consequence of many vascular complains and serves as one of the biomarkers for these diseases. Furthermore, emerging evidence supports that OS and angiogenesis play vital roles in many dermatoses, such as psoriasis, atopic dermatitis, and skin tumor. This review summarizes recent findings on the role of OS as a trigger of angiogenesis in skin disorders, highlights newly identified mechanisms, and introduces the antiangiogenic and antioxidant therapeutic strategies.