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1.
J AOAC Int ; 2024 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-39352784

RESUMO

BACKGROUND: The genus Usnea (Parmeliaceae; lichenized Ascomycetes) is pale grayish-green fruticose lichens which grow as leafless mini-shrubs and comprise about 360 species. Most of the Usnea species are edible and is utilized in preparation of traditional foods as well as in medicines to combat wide range of ailments. OBJECTIVE: The goal of this work was to quantify usnic acid in three Usnea spp. [Usnea ghattensis (UG), Usnea orientalis (UO) and Usnea undulata (UU)] using HPTLC-MS and chemical profiling of acetone extracts using UPLC-QTof-MSE resulted in the identification of sixteen compounds based on their MS/MS fragmentation patterns. METHODS: Hyphenated techniques, HPTLC-MS and UPLC-QTof-MSE have been proposed to quantify usnic acid and analysis of metabolites in the crude extracts qualitatively. This method allowed tentative characterization of metabolites from Usnea spp. RESULTS: The quantification study showed the excellent linearity of the usnic acid at 0.25-1 µg/band with a correlation coefficient r  2>0.99, and LOD, LOQ was found to be 51.7 and 156.6 ng/band, respectively. Further, UPLC-QTof-MSE analysis of crude extract led identification of lichen substances through their exact molecular masses and MS/MS fragmentation studies. CONCLUSIONS: The present study summarizes HPTLC method for quantification of usnic acid in three different Usnea spp. Along with two herbal formulations containing Usnea spp. as the ingredient and developed method was validated as per the ICH guidelines and further UPLC-QTof-MSE analysis provides characterization of the sixteen different secondary metabolites based on their mass fragmentation studies. HIGHLIGHTS: Rapid HPTLC method for quantification of usnic acid in three different Usnea spp. along with two herbal formulations and metabolite profiling using UPLC-QTof-MSE.

2.
Protein Pept Lett ; 2024 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-39323334

RESUMO

BACKGROUND: Breast cancer is a heterogeneous type of disease in which genetic and environmental factors play a crucial role. There are several types of treatment for breast cancer (BC) patients. However, the biggest problem in the treatment of breast cancer is the resistance that occurs during the treatment with chemotherapeutic agents. Usnic acid, a secondary metabolite of lichen, has been identified as a drug candidate molecule in cancer treatment. The determination of miRNA target proteins is essential for the understanding of molecular mechanisms of miRNA-related tumorigenesis. OBJECTIVES: We determined that mir-185-5p has therapeutic potential at the miRNA level by applying usnic acid to BT-474 breast cancer cells in a previous study. Herein, we aimed to investigate the molecular mechanisms of miR-185-5p on BT-474 breast cancer cells using a proteomics approach. We explored the changes in the protein expression level of BT-474 breast cancer cells in response to the up-regulation of miR-185-5p after applying usnic acid as a novel candidate anti-- cancer drug molecule. METHODS: We performed quantitative proteome analysis based on an LC-MS/MS assay, which was validated by western blotting. The differentially expressed proteins were analyzed using the latest data available in bioinformatics tools. The up-regulated expression of YWHAE, Cathepsin D, and the down-regulated levels of PAK-1 were demonstrated by western blot assay. RESULTS: According to the results, 86 proteins showing >2-fold change were identified as differentially expressed between breast cancer and normal breast epithelial cells. The apoptosis pathway was the main clade containing most of the proteins regulated by miR-185-5p. The results indicate that miR-185-5p modulates apoptosis signaling pathways in BT-474 breast cancer cells. Breast cancer inhibition due to increased expression of YWHAE, Cathepsin D, and decreased expression of PAK-1 is likely to be mediated by inducing miR-185-5p mediated apoptosis. CONCLUSION: In this study, the identification of miR-185-5p protein targets demonstrated the potential for the development of targeted therapy and the development of miRNA-based therapeutics and presented it as a biomarker for breast cancer diagnosis, prognosis, and treatment response. In this regard, proteome analyses provided an understanding of the molecular mechanism underlying the effect of miR-185-5p on breast cancer.

3.
ACS Chem Neurosci ; 15(17): 3152-3167, 2024 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-39145537

RESUMO

Preclinical and clinical studies have indicated that compromised blood-brain barrier (BBB) function contributes to Alzheimer's disease (AD) pathology. BBB breakdown ranged from mild disruption of tight junctions (TJs) with increased BBB permeability to chronic integrity loss, affecting transport across the BBB, reducing brain perfusion, and triggering inflammatory responses. We recently developed a high-throughput screening (HTS) assay to identify hit compounds that enhance the function of a cell-based BBB model. The HTS screen identified (S,E)-2-acetyl-6-[3-(4'-fluorobiphenyl-4-yl)acryloyl]-3,7,9-trihydroxy-8,9b-dimethyldibenzo-[b,d]furan-1(9bH)-one (4-FPBUA), a semisynthetic analogue of naturally occurring usnic acid, which protected the in vitro model against Aß toxicity. Usnic acid is a lichen-derived secondary metabolite with a unique dibenzofuran skeleton that is commonly found in lichenized fungi of the genera Usnea. In this study, we aimed to evaluate the effect of 4-FPBUA in vitro on the cell-based BBB model function and its in vivo ability to rectify BBB function and reduce brain Aß in two AD mouse models, namely, 5xFAD and TgSwDI. Our findings demonstrated that 4-FPBUA enhanced cell-based BBB function, increased Aß transport across the monolayer, and reversed BBB breakdown in vivo by enhancing autophagy as an mTOR inhibitor. Induced autophagy was associated with a significant reduction in Aß accumulation and related pathologies and improved memory function. These results underscore the potential of 4-FPBUA as a candidate for further preclinical exploration to better understand its mechanisms of action and to optimize dosing strategies. Continued research may also elucidate additional pathways through which 4-FPBUA contributed to the amelioration of BBB dysfunction in AD. Collectively, our findings supported the development of 4-FPBUA as a therapeutic agent against AD.


Assuntos
Doença de Alzheimer , Autofagia , Benzofuranos , Barreira Hematoencefálica , Modelos Animais de Doenças , Animais , Barreira Hematoencefálica/efeitos dos fármacos , Barreira Hematoencefálica/metabolismo , Doença de Alzheimer/tratamento farmacológico , Doença de Alzheimer/metabolismo , Benzofuranos/farmacologia , Autofagia/efeitos dos fármacos , Autofagia/fisiologia , Camundongos , Peptídeos beta-Amiloides/metabolismo , Camundongos Transgênicos , Humanos
4.
Food Chem ; 458: 140286, 2024 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-38968714

RESUMO

Lichens have great potential as food, functional food additives or flavourings. The presence of specific substances with multiple biological activities is one of the characteristics of lichens. However, research on lichens as a food source or functional food additive is limited. The present study simulated, for the first time, the potential bioaccessibility of active compounds from 6 lichen species in simulated gastric and intestinal conditions. An in vitro digestion showed that the lichen substances had different bioaccessibility and stability during digestion. It was found that the application of some metabolic modulators significantly altered the accumulation of metabolites in most species. In addition, the study demonstrated the antimicrobial activity of the tested extracts as well as of 14 isolated lichen metabolites. These multi-directional studies demonstrate the potential of lichens in terms of their use as antimicrobial functional food additives.


Assuntos
Digestão , Alimento Funcional , Líquens , Líquens/química , Líquens/metabolismo , Alimento Funcional/análise , Humanos , Aditivos Alimentares/metabolismo , Aditivos Alimentares/análise , Aditivos Alimentares/farmacologia , Aditivos Alimentares/química , Modelos Biológicos , Bactérias/metabolismo , Bactérias/efeitos dos fármacos , Anti-Infecciosos/farmacologia , Anti-Infecciosos/metabolismo , Anti-Infecciosos/química
5.
Reprod Toxicol ; 128: 108654, 2024 09.
Artigo em Inglês | MEDLINE | ID: mdl-38960207

RESUMO

Testicular torsion (TT) is a urological condition that can result in infertility in men. The etiopathogenesis of TT includes ischemia/reperfusion injury (IRI) characterized by oxidative stress (OS), inflammation and apoptosis resulting from increased levels of free radicals. Usnic acid (UA), a dibenzofuran, is one of the most common metabolites found in lichens and is known to possess powerful antioxidant properties. The aim of this study was to investigate the potential protective activity of UA in an experimental testicular IRI model for the first time. A total of 18 rats were randomly assigned to three groups (n=6): sham control, IRI and IRI+UA. The IRI groups underwent a four-hour period of ischemia and a two-hour period of reperfusion. The OS, inflammation, endoplasmic reticulum stress (ERS) and apoptosis markers in testicular tissue were evaluated using colorimetric methods. Furthermore, tissue samples were subjected to histological examination, with staining using hematoxylin and eosin. Histopathological findings supported by increased OS, inflammation, ERS and apoptosis levels were obtained in IRI group compared with sham control group. However, UA treatment restored these pathological and biochemical changes. Although this study provides the first preliminary evidence that UA may be used as a useful molecule against testicular IRI, further extensive molecular preclinical studies should be performed before clinical use is considered.


Assuntos
Apoptose , Benzofuranos , Estresse do Retículo Endoplasmático , Traumatismo por Reperfusão , Testículo , Animais , Masculino , Benzofuranos/farmacologia , Benzofuranos/uso terapêutico , Traumatismo por Reperfusão/tratamento farmacológico , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Testículo/efeitos dos fármacos , Testículo/patologia , Testículo/metabolismo , Apoptose/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Ratos Wistar , Torção do Cordão Espermático/tratamento farmacológico , Ratos , Antioxidantes/farmacologia , Antioxidantes/uso terapêutico
6.
Turk J Pharm Sci ; 21(3): 243-251, 2024 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-38994865

RESUMO

Objectives: Lichens are complex symbiotic organisms that generate various bioactive compounds with significant therapeutic value. We investigated the chemical composition and bioactivity of the acetone extract of the Algerian lichen Physconia venusta (Ach.) poet. Materials and Methods: Phytochemical screening was performed using gas chromatography-mass spectrometry (GC-MS). The antibacterial activity was assessed against Escherichia coli, Pseudomonas aeruginosa, Salmonella enteritidis, Salmonella typhi, Staphylococcus aureus, Listeria monocytogenes, and Bacillus subtilis using an agar diffusion test with the determination of the minimal inhibition concentration (MIC), while the antioxidant activity was determined using different chemical methods (DPPH, ABTS, CUPRAC, reducing power, superoxide anion scavenging, ß-carotene bleaching, and metal chelate). In addition, cytotoxic activity was tested using Artemia salina (Brine shrimp) bioassay. Results: The studied extract exhibited intense antibacterial activity against E. coli and S. aureus with inhibition diameters of 28 ± 0.01 and 22 ± 0.01 mm, respectively, with a MIC value of 6.25 mg/mL and a selectivity index of 2.8. The obtained extract showed different antioxidant trends depending on the selected assay. GC-MS analysis revealed many secondary metabolites. Conclusion: P. venusta, a type of lichen, is a potential source of bioactive substances that could be used in pharmaceuticals.

7.
Nat Prod Res ; : 1-9, 2024 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-39021087

RESUMO

A new series of usnic acid (UA) monoesterified derivatives 2-15 were designed and synthesised using UA (1) as starting material. The structural characterisation of all compounds was elucidated using 1H-NMR and 13C-NMR spectral data. In vitro studies demonstrated thatmost UA derivatives exhibited higher inhibitory activity against Candida albicans and Staphylococcus aureus. Among them, compound 7 displayed the highest inhibitory activity against C. albicans with a minimum inhibitory concentration (MIC) of 32 µg/mL. Compounds 5, 8, 9, 11and 13 demonstrated superior inhibition of S. aureus (MIC, 16 µg/mL) and biofilm formation in a concentration-dependent manner. With the exception of 11, compounds 5, 8, 9 and 13 were all more effective than UA in inhibiting S. aureus biofilms. This research highlights the potential of UA monoesterified derivatives for the development of dual antimicrobial and antibiofilm agents.

8.
Antibiotics (Basel) ; 13(7)2024 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-39061313

RESUMO

With the increasing use of invasive, interventional, indwelling, and implanted medical devices, healthcare-associated infections caused by pathogenic biofilms have become a major cause of morbidity and mortality. Herein, we present the fabrication, characterization, and in vitro evaluation of biocompatibility and anti-biofilm properties of new coatings based on Fe3O4 nanoparticles (NPs) loaded with usnic acid (UA) and ceftriaxone (CEF). Sodium lauryl sulfate (SLS) was employed as a stabilizer and modulator of the polarity, dispersibility, shape, and anti-biofilm properties of the magnetite nanoparticles. The resulting Fe3O4 functionalized NPs, namely Fe3O4@SLS, Fe3O4@SLS/UA, and Fe3O4@SLS/CEF, respectively, were prepared by co-precipitation method and fully characterized by XRD, TEM, SAED, SEM, FTIR, and TGA. They were further used to produce nanostructured coatings by matrix-assisted pulsed laser evaporation (MAPLE) technique. The biocompatibility of the coatings was assessed by measuring the cell viability, lactate dehydrogenase release, and nitric oxide level in the culture medium and by evaluating the actin cytoskeleton morphology of murine pre-osteoblasts. All prepared nanostructured coatings exhibited good biocompatibility. Biofilm growth inhibition ability was tested at 24 h and 48 h against Staphylococcus aureus and Pseudomonas aeruginosa as representative models for Gram-positive and Gram-negative bacteria. The coatings demonstrated good biocompatibility, promoting osteoblast adhesion, migration, and growth without significant impact on cell viability or morphology, highlighting their potential for developing safe and effective antibacterial surfaces.

9.
ACS Appl Mater Interfaces ; 16(24): 31218-31227, 2024 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-38842482

RESUMO

With the rapid improvement of power conversion efficiency (PCE), perovskite solar cells (PSCs) have broad application prospects and their industrialization will be the next step. Nevertheless, the performance and long-term stability of the devices are limited by the defect-induced nonradiative recombination centers and ions' migration inside the perovskite films. Here, usnic acid (UA), an easy-to-obtain and efficient natural biomaterial with a hydroxyl functional group (-OH) and four carbonyl groups (-C═O) was added to MAPbI3 perovskite precursor to regulate the crystallization process by slowing the crystallization rate, thereby expanding the crystal size and preparing perovskite films with low defect density. In addition, UA anchors the uncoordinated Pb2+ and suppresses the migration of I-ions, which enhances the stability of the perovskite film. Consequently, an impressive PCE exceeding 20% was achieved for inverted structure MAPbI3-based PSCs. More impressively, the optimized PSCs maintained 78% of the initial PCE under air with high humidity (RH ≈ 65%, 25-30 °C) for 1000 h. UA can be extracted from the plant, usnea, making it inexpensive and easy to obtain. Our work demonstrates the application of the plant material in PSCs and their industrialization, which is significant nowadays.

10.
Artigo em Inglês | MEDLINE | ID: mdl-38904414

RESUMO

Since usnic acid was first isolated in 1844 as a prominent secondary lichen metabolite, it has been used for various purposes worldwide. Usnic acid has been claimed to possess numerous therapeutic properties, including antimicrobial, anti-inflammatory, antiviral, anti-proliferative, and antipyretic activities. Approximately two decades ago, crude extracts of usnic acid or pure usnic acid were marketed in the United States as dietary supplements for aiding in weight loss as a "fat-burner" and gained popularity in the bodybuilding community; however, hepatotoxicity was documented for some usnic acid containing products. The US Food and Drug Administration (FDA) received numerous reports of liver toxicity associated with the use of dietary supplements containing usnic acid, leading the FDA to issue a warning letter in 2001 on a product, LipoKinetix. The FDA also sent a recommendation letter to the manufacturer of LipoKinetix, resulting in the withdrawal of LipoKinetix from the market. These events triggered investigations into the hepatotoxicity of usnic acid and its mechanisms. In 2008, we published a review article titled "Usnic Acid and Usnea Barbata Toxicity". This review is an updated version of our previous review article and incorporates additional data published since 2008. The purpose of this review is to provide a comprehensive summary of the understanding of the liver toxicity associated with usnic acid, with a particular focus on the current understanding of the putative mechanisms of usnic acid-related hepatotoxicity.

11.
J Appl Toxicol ; 44(9): 1329-1346, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38724177

RESUMO

Dietary supplements containing usnic acid have been increasingly marketed for weight loss over the past decades, even though incidences of severe hepatotoxicity and acute liver failure due to their overuse have been reported. To date, the toxic mechanism of usnic acid-induced liver injury at the molecular level still remains to be fully elucidated. Here, we conducted a transcriptomic study on usnic acid using a novel in vitro hepatotoxicity model employing human induced pluripotent stem cell (iPSC)-derived hepatocytes. Treatment with 20 µM usnic acid for 24 h caused 4272 differentially expressed genes (DEGs) in the cells. Ingenuity Pathway Analysis (IPA) based on the DEGs and gene set enrichment analysis (GSEA) using the whole transcriptome expression data concordantly revealed several signaling pathways and biological processes that, when taken together, suggest that usnic acid caused oxidative stress and DNA damage in the cells, which further led to cell cycle arrest and eventually resulted in cell death through apoptosis. These transcriptomic findings were subsequently corroborated by a variety of cellular assays, including reactive oxygen species (ROS) generation and glutathione (GSH) depletion, DNA damage (pH2AX detection and 8-hydroxy-2'-deoxyguanosine [8-OH-dg] assay), cell cycle analysis, and caspase 3/7 activity. Collectively, the results of the current study accord with previous in vivo and in vitro findings, provide further evidence that oxidative stress-caused DNA damage contributes to usnic acid-induced hepatotoxicity, shed new light on molecular mechanisms of usnic acid-induced hepatotoxicity, and demonstrate the usefulness of iPSC-derived hepatocytes as an in vitro model for hepatotoxicity testing and prediction.


Assuntos
Apoptose , Benzofuranos , Dano ao DNA , Hepatócitos , Células-Tronco Pluripotentes Induzidas , Estresse Oxidativo , Espécies Reativas de Oxigênio , Humanos , Hepatócitos/efeitos dos fármacos , Hepatócitos/metabolismo , Hepatócitos/patologia , Dano ao DNA/efeitos dos fármacos , Células-Tronco Pluripotentes Induzidas/efeitos dos fármacos , Células-Tronco Pluripotentes Induzidas/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Benzofuranos/toxicidade , Apoptose/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Doença Hepática Induzida por Substâncias e Drogas/genética , Doença Hepática Induzida por Substâncias e Drogas/etiologia , Doença Hepática Induzida por Substâncias e Drogas/patologia , Doença Hepática Induzida por Substâncias e Drogas/metabolismo , Transcriptoma/efeitos dos fármacos , Glutationa/metabolismo , Células Cultivadas
12.
Viruses ; 16(2)2024 01 31.
Artigo em Inglês | MEDLINE | ID: mdl-38399993

RESUMO

Although the COVID-19 pandemic caused by SARS-CoV-2 viruses is officially over, the search for new effective agents with activity against a wide range of coronaviruses is still an important task for medical chemists and virologists. We synthesized a series of thiazolo-thiophenes based on (+)- and (-)-usnic acid and studied their ability to inhibit the main protease of SARS-CoV-2. Substances containing unsubstituted thiophene groups or methyl- or bromo-substituted thiophene moieties showed moderate activity. Derivatives containing nitro substituents in the thiophene heterocycle-just as pure (+)- and (-)-usnic acids-showed no anti-3CLpro activity. Kinetic parameters of the most active compound, (+)-3e, were investigated, and molecular modeling of the possible interaction of the new thiazolo-thiophenes with the active site of the main protease was carried out. We evaluated the binding energies of the ligand and protein in a ligand-protein complex. Active compound (+)-3e was found to bind with minimum free energy; the binding of inactive compound (+)-3g is characterized by higher values of minimum free energy; the positioning of pure (+)-usnic acid proved to be unstable and is accompanied by the formation of intermolecular contacts with many amino acids of the catalytic binding site. Thus, the molecular dynamics results were consistent with the experimental data. In an in vitro antiviral assay against six strains (Wuhan, Delta, and four Omicron sublineages) of SARS-CoV-2, (+)-3e demonstrated pronounced antiviral activity against all the strains.


Assuntos
Benzofuranos , COVID-19 , SARS-CoV-2 , Humanos , SARS-CoV-2/metabolismo , Pandemias , Ligantes , Inibidores de Proteases/farmacologia , Inibidores de Proteases/química , Simulação de Acoplamento Molecular , Proteínas não Estruturais Virais/metabolismo , Simulação de Dinâmica Molecular , Antivirais/uso terapêutico , Tiofenos/farmacologia , Peptídeo Hidrolases/metabolismo
13.
Polymers (Basel) ; 16(3)2024 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-38337316

RESUMO

The present study investigates the utilization of nanoparticles based on poly-l-lactide (PLLA) and polyglycerol adipate (PGA), alone and blended, for the encapsulation of usnic acid (UA), a potent natural compound with various therapeutic properties including antimicrobial and anticancer activities. The development of these carriers offers an innovative approach to overcome the challenges associated with usnic acid's limited aqueous solubility, bioavailability, and hepatotoxicity. The nanosystems were characterized according to their physicochemical properties (among others, size, zeta potential, thermal properties), apparent aqueous solubility, and in vitro cytotoxicity. Interestingly, the nanocarrier obtained with the PLLA-PGA 50/50 weight ratio blend showed both the lowest size and the highest UA apparent solubility as well as the ability to decrease UA cytotoxicity towards human hepatocytes (HepG2 cells). This research opens new avenues for the effective utilization of these highly degradable and biocompatible PLLA-PGA blends as nanocarriers for reducing the cytotoxicity of usnic acid.

14.
Mini Rev Med Chem ; 24(14): 1368-1384, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38265368

RESUMO

Usnic acid has a variety of biological activities, and has been widely studied in the fields of antibacterial, immune stimulation, antiviral, antifungal, anti-inflammatory and antiparasitic. Based on this, usnic acid is used as the lead compound for structural modification. In order to enhance the biological activity and solubility of usnic acid, scholars have carried out a large number of structural modifications, and found some usnic acid derivatives to be of more potential research value. In this paper, the structural modification, biological activity and structure-activity relationship of usnic acid were reviewed to provide reference for the development of usnic acid derivatives.


Assuntos
Benzofuranos , Benzofuranos/química , Benzofuranos/farmacologia , Relação Estrutura-Atividade , Humanos , Antibacterianos/química , Antibacterianos/farmacologia , Anti-Inflamatórios/química , Anti-Inflamatórios/farmacologia , Anti-Infecciosos/farmacologia , Anti-Infecciosos/química , Antivirais/química , Antivirais/farmacologia , Estrutura Molecular , Antifúngicos/farmacologia , Antifúngicos/química , Animais , Antiparasitários/química , Antiparasitários/farmacologia
15.
Int J Mol Sci ; 25(2)2024 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-38279210

RESUMO

Tyrosyl-DNA phosphodiesterase 1 (Tdp1) is an important DNA repair enzyme and one of the causes of tumor resistance to topoisomerase 1 inhibitors such as topotecan. Inhibitors of this Tdp1 in combination with topotecan may improve the effectiveness of therapy. In this work, we synthesized usnic acid derivatives, which are hybrids of its known derivatives: tumor sensitizers to topotecan. New compounds inhibit Tdp1 in the micromolar and submicromolar concentration range; some of them enhance the effect of topotecan on the metabolic activity of cells of various lines according to the MTT test. One of the new compounds (compound 7) not only sensitizes Krebs-2 and Lewis carcinomas of mice to the action of topotecan, but also normalizes the state of the peripheral blood of mice, which is disturbed in the presence of a tumor. Thus, the synthesized substances may be the prototype of a new class of additional therapy for cancer.


Assuntos
Benzofuranos , Carcinoma , Topotecan , Animais , Camundongos , Topotecan/farmacologia , Topotecan/uso terapêutico , Inibidores de Fosfodiesterase/farmacologia , Diester Fosfórico Hidrolases/metabolismo , Esterases
16.
Oecologia ; 204(1): 187-198, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38233688

RESUMO

The mat-forming fruticose lichens Cladonia stellaris and Cetraria islandica frequently co-occur on soils in sun-exposed boreal, subarctic, and alpine ecosystems. While the dominant reindeer lichen Cladonia lacks a cortex but produces the light-reflecting pale pigment usnic acid on its surface, the common but patchier Cetraria has a firm cortex sealed by the light-absorbing pigment melanin. By measuring reflectance spectra, high-light tolerance, photosynthetic responses, and chlorophyll fluorescence in sympatric populations of these lichens differing in fungal pigments, we aimed to study how they cope with high light while hydrated. Specimens of the two species tolerated high light equally well but with different protective mechanisms. The mycobiont of the melanic species efficiently absorbed excess light, consistent with a lower need for its photobiont to protect itself by non-photochemical quenching (NPQ). By contrast, usnic acid screened light at 450-700 nm by reflectance and absorbed shorter wavelengths. The ecorticate usnic species with less efficient fungal light screening exhibited a consistently lower light compensation point and higher CO2 uptake rates than the melanic lichen. In both species, steady state NPQ rapidly increased at increasing light with no signs of light saturation. To compensate for less internal shading causing light fluctuations with a larger amplitude, the usnic lichen photobiont adjusted to changing light by faster induction and faster relaxation of NPQ rapidly transforming excess excitation energy to less damaging heat. The high and flexible NPQ tracking fluctuations in solar radiation probably contributes to the strong dominance of the usnic mat-forming Cladonia in open lichen-dominated heaths.


Assuntos
Ascomicetos , Líquens , Parmeliaceae , Líquens/fisiologia , Ecossistema
17.
J Biochem Mol Toxicol ; 38(1): e23553, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37840363

RESUMO

In this study, we investigated the chemopreventive efficacy of usnic acid (UA), an effective secondary metabolite component of lichens, against 7,12-dimethylbenz[a]anthracene (DMBA)-induced oral squamous cell carcinoma (OSCC) in the hamster model. Initially, the buccal pouch carcinogenesis was induced by administering 0.5% DMBA to the HBP (hamster buccal pouch) region about three times a week until the 10th week. Then, UA was orally treated with different concentrations (25, 50, 100 mg/kg b.wt) on alternative days of DMBA exposure, and the experimental process ended in the 16th week. After animal experimentation, we observed 100% tumor incidence with well-differentiated OSCC, dysplasia, and hyperplasia lesions in the DMBA-induced HBP region. Furthermore, the UA treatment of DMBA-induced hamster effectively inhibited tumor growth. In addition, UA upregulated antioxidant levels, interfered with the elevated lipid peroxidation by-product of thiobarbituric acid reactive substances, and changed the activities of the liver detoxification enzyme (Phase I and II) in DMBA-induced hamsters. Furthermore, immunohistochemical staining of inflammatory markers (iNOS and COX-2) and proliferative cell markers (cyclin-D1 and PCNA) were upregulated in the buccal pouch part of hamster animals induced with DMBA. Notably, the oral administration of UA significantly suppressed these markers during DMBA-induced hamsters. Collectively, our findings revealed that UA exhibits antioxidant, anti-inflammatory, antitumor, and apoptosis-inducing characteristics, demonstrating UA's protective properties against DMBA-induced HBP carcinogenesis.


Assuntos
Benzofuranos , Carcinoma de Células Escamosas , Neoplasias Bucais , Cricetinae , Animais , Masculino , Mesocricetus , Antioxidantes/metabolismo , 9,10-Dimetil-1,2-benzantraceno/toxicidade , Carcinoma de Células Escamosas/induzido quimicamente , Neoplasias Bucais/induzido quimicamente , Neoplasias Bucais/prevenção & controle , Neoplasias Bucais/patologia , Carcinogênese/induzido quimicamente , Inflamação/induzido quimicamente , Inflamação/tratamento farmacológico , Estresse Oxidativo , Proliferação de Células , Antracenos , Carcinógenos/toxicidade
18.
Adv Healthc Mater ; 13(8): e2303216, 2024 03.
Artigo em Inglês | MEDLINE | ID: mdl-38156501

RESUMO

Bacterial cellulose is an extracellular polysaccharide produced by microorganisms, offering advantages such as high water-holding capacity, flexibility, and biocompatibility. However, its lack of bactericidal activity hampers its wide application. Usnic acid, a secondary metabolite derived from lichens of the Usnea genus, is recognized for its antibacterial and anti-biofilm efficiency, coupled with anti-inflammatory properties. Its water insolubility presents challenges for wide utilization and stable release. Sanxan gel, a novel polysaccharide, exhibits exceptional freeze-thaw stability, suspension properties, and high elasticity, rendering it effective as a suspending agent to improve the bioavailability of water-insoluble drugs. In this study, a hydrogel membrane is designed by combining bacterial cellulose and usnic acid suspended in sanxan gel through a simple in situ microorganism fermentation. The obtained membranes demonstrate excellent ability for sustained drug release, strong eradication capability against tested bacteria in both in vitro and in vivo experiments, effective inhibition of biofilm formation, and excellent hemocompatibility and cytocompatibility. Additionally, the composite membranes promote wound healing with reduced inflammation and bacterial infection in a full-thickness wound infection model in mice. This study provides innovative insights and strategies for the development of functional dressings for infected wounds in future clinical applications.


Assuntos
Celulose , Hidrogéis , Animais , Camundongos , Bactérias , Antibacterianos , Água
19.
Curr Med Chem ; 2023 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-37921177

RESUMO

In the field of precision and personalized medicine, the next generation sequencing method has begun to take an active place as genome-wide screening applications in the diagnosis and treatment of diseases. Studies based on the determination of the therapeutic efficacy of personalized drug use in cancer treatment in the size of the transcriptome and its extension, lncRNA, have been increasing rapidly in recent years. Targeting and/or regulating noncoding RNAs (ncRNAs) consisting of long noncoding RNAs (lncRNAs) are promising strategies for cancer treatment. Within the scope of rapidly increasing studies in recent years, it has been shown that many natural agents obtained from biological organisms can potentially alter the expression of many lncRNAs associated with oncogenic functions. Natural agents include effective small molecules that provide anti-cancer effects and have been used as chemotherapy drugs or in combination with standard anti-cancer drugs used in routine treatment. In this review, it was aimed to provide detailed information about the potential of natural agents to regulate and/or target non-coding RNAs and their mechanisms of action to provide an approach for cancer therapy. The discovery of novel anti-cancer targets and subsequent development of effective drugs or combination strategies that are still needed for most cancers will be promising for cancer treatment.

20.
In Silico Pharmacol ; 11(1): 36, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37994367

RESUMO

The finest sources of therapeutic agents are natural products, and usnic acid is a secondary metabolite derived from lichen that has a wide range of biological actions, including anti-viral, anti-cancer, anti-bacterial, and anti-diabetic (hyperglycemia). Based on the hyperglycemia activity of UA, this work seeks to identify new anti-hyperglycemia medicines by virtual screening of pyrazole derivatives of UA. Seven hit compounds (Compounds 1, 5, 6, 7, 17, 18 and 33), which finally go through docking-based screening to produce the lead molecule, were identified by the physicochemical attributes, drug-likeliness, and ADMET prediction. The docking score for the chosen compounds containing PPARγ agonists ranged from -7.6 to -9.2 kcal/mol, whereas the docking goal for compounds 5, 6, and 7 was -9.2 kcal/mol. Based on the binding energy and bound amino acid residues as well as compared to the reference compound, compound-6 considered as lead compound. Furthermore, the MD simulation of 3CS8-Compound-6 and 3CS8-Rosiglitazone complexes were performed to verify the stability of these complexes and the binding posture acquired in docking experiments. The compound-6 had strong pharmacological characteristics, bound to the PPARγ agonist active site, and was expected to reduce the activity of the receptor, according to the virtual screening results. It must be justified to conduct both in-vitro and in-vivo experiments to examine the efficacy of this compound. Supplementary Information: The online version contains supplementary material available at 10.1007/s40203-023-00176-y.

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