Search Results (921)

Sterols play important structural and regulatory roles in numerous intracellular processes. Unlike animals, plants contain a distinctive and diverse variety of sterols. Recently, information has emerged showing that stigmasterol is a “stress sterol”. Stigmasterol is synthesized via the mevalonate biosynthesis pathway and has structural similarity to β-sitosterol but differs in the presence of a trans-oriented double bond in the side chain. In plants, the accumulation of stigmasterol has been observed in response to various stresses. However, the precise ways that stigmasterol is involved in the stress responses of plants remain unclear. This comprehensive review provides an update on the biology of stigmasterol, particularly the physicochemical properties of this ethylsterol, its biosynthesis, and its occurrence in higher plants and extremophilic organisms, e.g., mosses and lichens. Special emphasis is given to the evolutionary aspects of stigmasterol biosynthesis, particularly the variations in the gene structure of C22-sterol desaturase, which catalyzes the formation of stigmasterol from β-sitosterol, in a diversity of evolutionarily distant organisms. The roles of stigmasterol in the tolerance of plants to hostile environments and the prospects for its biomedical applications are also discussed. Taken together, the available data suggest that stigmasterol plays important roles in plant metabolism, although in some aspects, it remains an enigmatic compound. Full article

Platelet-rich fibrin (PRF), originally used to support soft tissue healing, is also considered a therapeutic option for treating oral lichen planus and leukoplakia. The progression from the two premalignant lesions to the aggressive malignant oral squamous cell carcinoma involves an inflammatory process linked to chemokine expression. Thus, there is a rationale for studying how PRF modulates the expression of chemokines in oral squamous carcinoma cells. To this aim, we expose the oral squamous carcinoma cell line HSC2 to IL1β and TNFα either alone or in the presence of lysates obtained from solid PRF membranes. We report here that in HSC2 cells, PRF lysates significantly reduce the forced transcription of chemokines, e.g., CXCL1, CXCL2, CXCL8, CXCL10, and CCL5. Moreover, PRF lysates attenuate the nuclear translocation of p65 in HSC2 oral epithelial cells when exposed to IL1β and TNFα. PRF lysates further reduce chemokine expression provoked by poly:IC HMW. Even though less pronounced, PRF lysates reduce IL1β- and TNFα-induced chemokine expression in TR146 cells. In primary oral epithelial cells, however, PRF lysates increase the basal expression of CXCL1, CXCL2 and CXCL8. Thus, PRF can exert a biphasic effect on chemokine expression in oral squamous cell carcinoma cell lines and primary oral epithelial cells. These findings suggest that PRF may reduce inflammation in a malignant environment while provoking an immunological response in healthy oral epithelium. Full article

We aimed to qualitatively and quantitatively analyze, through a systematic review and meta-analysis, the current evidence on the differential expression of the hallmarks of cancer in oral lichen planus (OLP) samples, in order to know the earliest molecular mechanisms that could be involved in the malignant transformation of this oral potentially malignant disorder. We searched MEDLINE/PubMed, Embase, Web of Science, and Scopus for studies published before November 2023. We evaluated the methodological quality of studies and carried out meta-analyses to fulfill our objectives. Inclusion criteria were met by 110 primary-level studies, with 7065 OLP samples, in which the expression of 104 biomarkers were analyzed through immunohistochemistry. Most OLP samples showed sustained cell proliferation signaling (65.48%, 95%CI = 51.87–78.02), anti-apoptotic pathways (55.93%, 95%CI = 35.99–75.0), genome instability (48.44%, 95%CI = 13.54–84.19), and tumor-promoting inflammation events (83.10%, 95%CI = 73.93–90.74). Concurrently, OLP samples also harbored tumor growth suppressor mechanisms (64.00%, 95%CI = 53.27–74.12). In conclusion, current evidence indicates that molecular mechanisms promoting hyperproliferative signaling, an antiapoptotic state with genomic instability, and an escape of epithelial cells from immune destruction, are developed in LP-affected oral mucosa. It is plausible that these events are due to the actions exerted by the chronic inflammatory infiltrate. Malignant transformation appears to be prevented by tumor suppressor genes, which showed consistent upregulation in OLP samples. Full article

Extramammary Paget disease (EMPD) is an uncommon adenocarcinoma of apocrine gland-rich areas, presenting significant diagnostic challenges due to its nonspecific clinical appearance and frequent misidentification as benign, inflammatory skin conditions. Traditional diagnostic methods such as biopsy are invasive and uncomfortable, often required repeatedly due to high recurrence rates. Dermoscopy and non-invasive imaging techniques have been used but provide limited diagnostic accuracy due to their constraints in depth penetration and resolution. Recent advancements in imaging technologies, such as line-field confocal optical coherence tomography (LC-OCT), show promise in enhancing diagnostic precision while minimizing invasive procedures. LC-OCT merges high-resolution imaging with deep penetration capabilities, capturing detailed horizontal and vertical skin images akin to histopathology. This study evaluated the diagnostic performance of LC-OCT in detecting EMPD and its recurrence in 17 clinically suspicious anogenital regions, belonging to six patients. Data were collected prospectively at the patient’s bedside by an LC-OCT expert with poor training for EMPD, and, then, reviewed retrospectively by an independent LC-OCT expert with adequate training for EMPD and no concerns about time. The prospective examination yielded 64.7% accuracy (11 true results out of 17 total cases), 71.4% sensitivity (10 true positives out of 14 actual positives), and 33.3% specificity (1 true negative out of 3 actual negatives). The retrospective analysis achieved 94.1% accuracy (16 true results out of 17 total cases), 100% sensitivity (14 true positives out of 14 actual positives), and 66.7% specificity (2 true positives out of 3 actual positives), with the only false positive case being a difficult-to-diagnose concomitant presentation of a lichen sclerosus et atrophicus. Despite the need for specialized training, our results suggest that LC-OCT represents a valuable tool for accurately identifying EMPD and improving its management by reducing unnecessary biopsies. Further studies are needed to standardize its clinical application. Full article

The diagnosis of oral lichen planus (OLP) poses many challenges due to its nonspecific clinical symptoms and histopathological features. Therefore, the diagnostic process should include a thorough clinical history, immunological tests, and histopathology. Our study aimed to enhance the diagnostic accuracy of OLP by integrating direct immunofluorescence (DIF) results with clinical data to develop a multivariate predictive model based on the Artificial Neural Network. Eighty patients were assessed using DIF for various markers (immunoglobulins of classes G, A, and M; complement 3; fibrinogen type 1 and 2) and clinical characteristics such as age, gender, and lesion location. Statistical analysis was performed using machine learning techniques in Statistica 13. The following variables were assessed: gender, age on the day of lesion onset, results of direct immunofluorescence, location of white patches, locations of erosions, treatment history, medications and dietary supplement intake, dental status, smoking status, flossing, and using mouthwash. Four statistically significant variables were selected for machine learning after the initial assessment. The final predictive model, based on neural networks, achieved 85% in the testing sample and 71% accuracy in the validation sample. Significant predictors included stress at onset, white patches under the tongue, and erosions on the mandibular gingiva. In conclusion, while the model shows promise, larger datasets and more comprehensive variables are needed to improve diagnostic accuracy for OLP, highlighting the need for further research and collaborative data collection efforts. Full article

Hepatitis C virus (HCV) infection is a global health concern with significant systemic implications, including a range of oral manifestations. This review aims to provide a comprehensive overview of the oral and dental pathologies related to HCV, the etiopathogenetic mechanisms linking such conditions to HCV and the impact of direct-acting antiviral (DAA) therapy. Common oral manifestations of HCV include oral lichen planus (OLP), periodontal disease, and xerostomia. The pathogenesis of these conditions involves both direct viral effects on oral tissues and indirect effects related to the immune response to HCV. Our literature analysis, using PubMed, Scopus, Web of Science, and Google Scholar, suggests that both the HCV infection and the immune response to HCV contribute to the increased prevalence of these oral diseases. The introduction of DAA therapy represents a significant advancement in HCV treatment, but its effects on oral manifestations, particularly OLP, are still under evaluation. Although a possible mechanism linking HCV to OSCC is yet to be determined, existing evidence encourages further investigation in this sense. Our findings highlight the need for established protocols for managing the oral health of patients with HCV, aiming to improve outcomes and quality of life. Full article

The catalytic capabilities of metals in degrading azo dyes have garnered extensive interest; however, selecting highly efficient metals remains a significant challenge. We have developed a Zn-Ca-based metallic glass composite which shows outstanding degradation efficiency for Direct Blue 6. This alloy comprises a Zn₂Ca crystalline phase and an amorphous matrix, allowing for the degradation of azo dyes within minutes in a wide temperature range of 0–60 °C. Kinetic calculations reveal an exceptionally low activation energy of 8.99 kJ/mol. The rapid degradation is attributed to the active element Ca and the unique amorphous structure of the matrix, which not only facilitates abundant redox conditions but also minimizes the hydrolysis of the active element. The newly developed metallic glass composite exhibits a notably higher azo dye degradation rate compared to those of general metallic glasses, offering a new avenue for the rapid degradation of azo dyes. This paper holds significant importance for the development of novel azo dye wastewater treatment agents. Full article

The corrosion resistance of bearing materials is crucial for the long-term service and high precision of modern equipment, and has aroused widespread research interest. Inoculation treatment is beneficial for improving the mechanical properties of GCr15 bearing steel, but its impact on corrosion behavior remains to be investigated. In the present work, the influence of inoculation treatment on the corrosion morphology, open circuit potential, impedance spectrum, and polarization curve evolution of GCr15 steel was studied through in situ corrosion morphology analysis and electrochemical testing. The results showed that the samples treated after inoculation showed a reduced tendency for pitting corrosion and an obviously improved corrosion resistance. This improvement is related to the transformation of columnar grains into equiaxed grains during the inoculation process, which reduces the amount and distribution of inclusions and pores, thereby delaying the rapid development of pitting corrosion. This study provides new insights into the corrosion mechanism of gestational steel. Full article

The gut microbiota plays a crucial role in regulating energy metabolism, facilitating nutrient absorption, and supporting immune function, thereby assisting the host in adapting to seasonal dietary changes. Here, we compare the gut microbiome composition of wild gray snub-nosed monkeys during winter (from October to December) and spring (from January to March) to understand differences in seasonal nutrient intake patterns. Snub-nosed monkeys are foregut fermenters and consume difficult-to-digest carbohydrates and lichen. To examine the digestive adaptations of gray snub-nosed monkeys, we collected 14 fresh fecal samples for DNA analysis during the winter and spring. Based on 16S rRNA sequencing, metagenomic sequencing, and functional metagenomic analyses, we identified that Firmicutes, Actinobacteria, Verrucomicrobia, and Bacteroidetes constitute a keystone bacterial group in the gut microbiota during winter and spring and are responsible for degrading cellulose. Moreover, the transition in dietary composition from winter to spring was accompanied by changes in gut microbiota composition, demonstrating adaptive responses to varying food sources and availability. In winter, the bacterial species of the genera Streptococcus were found in higher abundance. At the functional level, these bacteria are involved in fructose and mannose metabolism and galactose metabolism c-related pathways, which facilitate the breakdown of glycogen, starch, and fiber found in fruits, seeds, and mature leaves. During spring, there was an increased abundance of bacteria species from the Prevotella and Lactobacillus genera, which aid the digestion of protein-rich buds. Combined, these findings reveal how the gut microbiota adjusts to fluctuations in energy balance and nutrient intake across different seasons in this critically endangered species. Moreover, we also identified Pseudomonas in two samples; the presence of potential pathogens within the gut could pose a risk to other troop members. Our findings highlight the necessity of a conservation plan that focuses on protecting vegetation and implementing measures to prevent disease transmission for this critically endangered species. Full article

Lichens are symbiotic organisms that effectively survive in harsh environments, including arid regions. Maintaining viability with an almost complete loss of water and the rapid restoration of metabolism during rehydration distinguishes lichens from most eukaryotic organisms. The lichen Xanthoria parietina is known to have high stress tolerance, possessing diverse defense mechanisms, including the presence of the bright-orange pigment parietin. While several studies have demonstrated the photoprotective and antioxidant properties of this anthraquinone, the role of parietin in the tolerance of lichens to desiccation is not clear yet. Thalli, which are exposed to solar radiation and become bright orange, may require enhanced desiccation tolerance. Here, we showed differences in the anatomy of naturally pale and bright-orange thalli of X. parietina and visualized parietin crystals on the surface of the upper cortex. Parietin was extracted from bright-orange thalli by acetone rinsing and quantified using HPLC. Although acetone rinsing did not affect PSII activity, thalli without parietin had higher levels of lipid peroxidation and a lower membrane stability index in response to desiccation. Furthermore, highly pigmented thalli possess thicker cell walls and, according to thermogravimetric analysis, higher water-holding capacities than pale thalli. Thus, parietin may play a role in desiccation tolerance by stabilizing mycobiont membranes, providing an antioxidative defense, and changing the morphology of the upper cortex of X. parietina. Full article

Atopic dermatitis, psoriasis and lichen sclerosus are among the most challenging conditions treated by dermatologists worldwide, with potentially significant physical, social and psychological impacts. Emerging evidence suggests that autologous-platelet-rich plasma could be used to manage skin inflammation. However, the presence of soluble autoimmune components could hinder their therapeutic potential. The aim of this study was to analyze the proteomic profile of plasma rich in growth factors (PRGFs) obtained from donors with inflammatory skin conditions to evaluate the impact of skin health status on the composition and bioactivity of PRGF-based treatments. Venous blood from healthy volunteers and patients with psoriasis, lichen sclerosus and atopic dermatitis was processed to produce PRGF supernatant. Half of the samples were subjected to an additional thermal treatment (56 °C) to inactivate inflammatory and immune molecules. Proteomic analysis was performed to assess the protein profile of PRGFs from healthy and non-healthy patients and the effect of Immunosafe treatment. Differential abundance patterns of several proteins related to key biological processes have been identified, including complement activation, blood coagulation, and glycolysis- and gluconeogenesis-related genes. These results also demonstrate that the thermal treatment (Immunosafe) contributes to the inactivation of the complement system and, as a consequence, reduction in the immunogenic potential of PRGF products. Full article

The richness, composition, abundance, and correlation with the atmospheric oxide concentrations of the community of corticolous lichens in the urban and peri-urban areas of the city of Ibagué (Colombia) were evaluated, selecting 25 individuals of the four most abundant phorophyte species. Twenty-nine lichen taxa grouped in 13 families and 17 genera were recorded, with a higher lichen coverage and taxa richness in the urban area. A non-metric multidimensional scaling (NMDS) analysis showed the conformation of two lichen communities associated with the urban and peri-urban areas of the city, and variation in composition among the phorophyte species. Exclusive and indicator taxa were found for both zones, as well as associations between variables through the application of a general linear model. Higher concentrations of atmospheric gases CO, SO₂, NO₂, and O₃ were found in the urban zone, and positive/negative relationships with some lichen taxa. There is high variability in the response of the lichen assemblage of urban and peri-urban ecosystems to environmental effects, with substantial or minimal changes in the variables of richness, coverage, and phorophyte association, and according to their interaction with atmospheric oxides, the patterns of potential tolerant and/or sensitive species are formed for their implementation in bioindication studies. Full article

Lichen planus (LP) is a chronic, recurrent mucocutaneous inflammatory disease with unclearly defined etiology, where a potential role of several viruses has been considered. This meta-analysis aimed to determine the potential association between HPV and oral LP based on case-control and cross-sectional study results. A systematic search was performed in PubMed, Web of Science (SCI), Google Scholar, and Scopus databases with the last update on 6 March 2024. Pooled data were analyzed by calculating odds ratios (OR) and 95% confidence intervals (CI) with the metafor package for R. A total of 13 studies on 541 cases and 413 controls were included in this meta-analysis. It covered eight countries: India, Iran, Turkey, Czech Republic, Hungary, Italy, Macedonia, and the UK. In seven papers, the differentiation into the erosive-atrophic type and non-erosive-atrophic type of OLP was utilized. HPV infection was associated with at least a two times higher risk for a person with HPV to have OLP, depending on whether original data or filled/trimmed data were used. The OR values were 3.54 [2.01, 6.24] and 2.10 [1.16, 3.82], respectively. This meta-analysis was performed to identify the association between HPV and OLP and revealed that HPV infection was associated with at least a high risk for a person with HPV to develop OLP. Full article

Background and Objectives: An oral lichen planus (OLP) chronic lesion refers to a group of oral potentially malignant disorders (OPMDs) that still lack a proper understanding from the point of view of relevant biomarkers for diagnostics and prognosis. The aim of the study was to assess the salivary histamine levels in patients with oral lichen planus lesions. Materials and Methods: The study included a group of 76 patients with oral lichen planus. General diseases and medication taken, smoking habits, severity of pain assessed using a visual analogue scale (VAS), oral hygiene status, and duration of OLP were evaluated. ELISA diagnostics for histamines in saliva levels were assessed. Results: The histamine levels in the OLP group were higher (0.468) in comparison with the control group (0.056), without a statistically significant value p = 0.090 (Mann–Whitney U Test). The median age of 76 OLP patients was 63 years (min 22.0–max. 81), with the biological sex being 80.3% females and 15 19.7% males. The average duration of OLP lesion presence was 29.4 months (SD 37.1) and the median value was 14.5 months. The median of the VAS was 3.0. OLP assessment in accordance with the Malhotra methodology showed the highest frequency—30.3% for only two of the point areas involved and 17.1% for three points. Clinical assessment of the different OLP grades, severity, and oral site involvement and the VAS in correlation with histamine salivary levels showed a lack of statistical significance in the investigated population. Conclusions: Undertaking further research could provide further possibilities for searching for general factors in OLP development. Full article

Gyrophoric acid (GA), a lichen secondary metabolite, has attracted more attention during the last years because of its potential biological effects. Until now, its effect in vivo has not yet been demonstrated. The aim of our study was to evaluate the basic physicochemical and pharmacokinetic properties of GA, which are directly associated with its biological activities. The stability of the GA in various pH was assessed by conducting repeated UV-VIS spectral measurements. Microsomal stability in rat liver microsomes was performed using Ultra-Performance LC/MS. Binding to human serum albumin (HSA) was assessed using synchronous fluorescence spectra, and molecular docking analysis was used to reveal the binding site of GA to HSA. In the in vivo experiment, 24 Sprague-Dawley rats (Velaz, Únetice, Czech Republic) were used. The animals were divided as follows. The first group (n = 6) included healthy males as control intact rats (♂INT), and the second group (n = 6) included healthy females as controls (♀INT). Groups three and four (♂GA/n = 6 and ♀GA/n = 6) consisted of animals with daily administered GA (10 mg/kg body weight) in an ethanol-water solution per os for a one-month period. We found that GA remained stable under various pH and temperature conditions. It bonded to human serum albumin with the binding constant 1.788 × 10⁶ dm³mol⁻¹ to reach the target tissue via this mechanism. In vivo, GA did not influence body mass gain, food, or fluid intake during the experiment. No liver toxicity was observed. However, GA increased the rearing frequency in behavioral tests (p < 0.01) and center crossings in the elevated plus-maze (p < 0.01 and p < 0.001, respectively). In addition, the time spent in the open arm was prolonged (p < 0.01 and p < 0.001, respectively). Notably, GA was able to pass through the blood–brain barrier, indicating its ability to permeate into the brain and to stimulate neurogenesis in the hilus and subgranular zone of the hippocampus. These observations highlight the potential role of GA in influencing brain function and neurogenesis. Full article