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Bioelectrochemistry (Amsterdam,... Feb 2023The electrochemically driven cytochrome P450 reactions have great promise as drug sensing device, new drug searching tool and bioreactor with broad synthetic...
The electrochemically driven cytochrome P450 reactions have great promise as drug sensing device, new drug searching tool and bioreactor with broad synthetic application. In the present work, we proposed approaches for the increasing the efficiency of cytochrome P450 3A4 electrocatalysis, based on fine regulation and reproduction of nature hemeprotein catalytic cycle and electron transfer pathways on electrode. To analyze the comparative electrochemical and electrocatalytic activity, cytochrome P450 3A4 was immobilized on electrodes modified with a membrane-like synthetic surfactant, didodecyldimethylammonium bromide (DDAB). We used riboflavin, FMN and FAD as low molecular models of NADPH-dependent cytochrome P450 reductase for the improving and enhancement properties of catalytically responsible cytochrome P450 3A4-electrode. The efficiencies of electrocatalysis of erythromycin N-demethylation as well-known cytochrome P450 3A4 substrate in the case of riboflavin, FAD and FMN as electron transfer mediators were 135 ± 6, 171 ± 15 and 203 ± 10 %, respectively (in comparison with 100 ± 18 % erythromycin N-demethylation in the case of cytochrome P450 3A4-electrode as catalyst). Molecular modeling of cytochrome P450 3A4 complexes with riboflavin, FMN and FAD confirms possibility of binding isoalloxazine ring of riboflavin to the protein on the proximal side of hemeprotein, which is the place for binding of redox partners of the cytochrome P450.
Topics: Flavin-Adenine Dinucleotide; Flavin Mononucleotide; NADPH-Ferrihemoprotein Reductase; Cytochrome P-450 Enzyme System; Erythromycin
PubMed: 36198256
DOI: 10.1016/j.bioelechem.2022.108277 -
Der Ophthalmologe : Zeitschrift Der... Apr 2022Keratoconus is classified as a corneal ectasia and is a multifactorial disease. In those affected, mostly adolescent patients visual deterioration occurs due to the... (Review)
Review
BACKGROUND
Keratoconus is classified as a corneal ectasia and is a multifactorial disease. In those affected, mostly adolescent patients visual deterioration occurs due to the development of irregular astigmatism. Treatment by corneal cross-linking (CXL) has been indicated in progressive disease for several years.
OBJECTIVE
To present the pathophysiology and histological changes in keratoconus as well as wound healing processes after CXL and their potential complications.
MATERIAL AND METHODS
Histological changes in keratoconus as well as wound healing processes after CXL and their potential complications are presented based on histological examination of corneal specimens with keratoconus with and without a condition after CXL. Relevant literature and own data are analyzed and discussed.
RESULTS
Besides inflammatory processes, atopic and genetic dispositions play a role in the development of keratoconus. The histological characteristics of keratoconus include changes in the epithelium, Bowman's layer and stroma. Wound healing processes after CXL include healing of the surface epithelium and transient loss of keratocytes and nerve fibers.
CONCLUSION
Keratoconus shows characteristic histopathological changes, such as epithelial irregularities, stromal thinning and breaks of Bowman's layer, whereas the endothelium and Descemet's membrane remain unchanged (apart from cases of corneal hydrops). After CXL wound healing processes can be followed primarily in vivo by confocal microscopy. Complications after CXL are rare. Persistent loss of keratocytes can be clinically manifested as a visually relevant scar.
Topics: Adolescent; Collagen; Corneal Stroma; Corneal Topography; Cross-Linking Reagents; Humans; Keratoconus; Photosensitizing Agents; Riboflavin; Ultraviolet Rays; Wound Healing
PubMed: 34874483
DOI: 10.1007/s00347-021-01537-8 -
Microbial Cell Factories Aug 2019Roseoflavin, a promising broad-spectrum antibiotic, is naturally produced by the bacteria Streptomyces davaonensis and Streptomyces cinnabarinus. The key enzymes...
BACKGROUND
Roseoflavin, a promising broad-spectrum antibiotic, is naturally produced by the bacteria Streptomyces davaonensis and Streptomyces cinnabarinus. The key enzymes responsible for roseoflavin biosynthesis and the corresponding genes were recently identified. In this study we aimed to enhance roseoflavin production in S. davaonensis and to synthesize roseoflavin in the heterologous hosts Bacillus subtilis and Corynebacterium glutamicum by (over)expression of the roseoflavin biosynthesis genes.
RESULTS
While expression of the roseoflavin biosynthesis genes from S. davaonensis was not observed in recombinant strains of B. subtilis, overexpression was successful in C. glutamicum and S. davaonensis. Under the culture conditions tested, a maximum of 1.6 ± 0.2 µM (ca. 0.7 mg/l) and 34.9 ± 5.2 µM (ca. 14 mg/l) roseoflavin was produced with recombinant strains of C. glutamicum and S. davaonensis, respectively. In S. davaonensis the roseoflavin yield was increased by 78%.
CONCLUSIONS
The results of this study provide a sound basis for the development of an economical roseoflavin production process.
Topics: Anti-Bacterial Agents; Bacillus subtilis; Corynebacterium glutamicum; Metabolic Engineering; Riboflavin; Streptomyces
PubMed: 31451111
DOI: 10.1186/s12934-019-1181-2 -
Methods in Molecular Biology (Clifton,... 2021The aim of this short review chapter is to provide a brief summary of the relevance of riboflavin (Rf or vitamin B2) and its derived cofactors flavin mononucleotide... (Review)
Review
The aim of this short review chapter is to provide a brief summary of the relevance of riboflavin (Rf or vitamin B2) and its derived cofactors flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD) for human neuromuscular bioenergetics.Therefore, as a completion of this book we would like to summarize what kind of human pathologies could derive from genetic disturbances of Rf transport, flavin cofactor synthesis and delivery to nascent apoflavoproteins, as well as by alteration of vitamin recycling during protein turnover.
Topics: Energy Metabolism; Flavin Mononucleotide; Flavin-Adenine Dinucleotide; Genetic Predisposition to Disease; Humans; Metabolism, Inborn Errors; Muscle, Skeletal; Neurons; Riboflavin
PubMed: 33751442
DOI: 10.1007/978-1-0716-1286-6_18 -
Current Eye Research Feb 2022This study aimed to investigate the clinical and histopathological effects of corneal cross-linking (CXL) and matrix-regenerating agent (RGTA) treatments after corneal...
PURPOSE
This study aimed to investigate the clinical and histopathological effects of corneal cross-linking (CXL) and matrix-regenerating agent (RGTA) treatments after corneal alkali burn.
MATERIALS AND METHODS
Twenty-four alkali-burned corneas from 24 rabbits were divided into three groups: control, CXL, and RGTA. All animals were investigated for epithelial healing, opacification, ulceration, and neovascularization at days 1, 7, 14, and 21 after the alkali burn. Corneas were excised and sent for histological examination on day 21.
RESULTS
One animal each from the CXL and control groups exhibited moderate ulceration, while no ulceration was observed in the RGTA group. No significant difference was observed among the groups in corneal thickness or corneal opacity measurements at the final visit ( = .058 and = .544, respectively). Both RGTA and CXL treatments were effective in terms of epithelial healing and neovascularization ( = .023 and = .03, respectively). On histological examination, the CXL and RGTA groups were more effective in treating epithelial loss, stromal edema, corneal vascularization, and leukocytic infiltration than the control group ( < .05). The immunohistochemical staining scores of the CXL and RGTA groups for caspase-3, vascular endothelial growth factor, and matrix metalloproteinase-9 in the epithelium and stroma were significantly lower than those in the control group ( < .05). In the immunohistochemical examination for inducible nitric oxide synthase, epithelial staining scores were similar among the groups ( > .05). In contrast, the stromal staining scores of the CXL and RGTA groups were lower than those of the control group ( < .05).
CONCLUSION
Both CXL and RGTA therapies were effective in reducing anatomical and histopathological complications after corneal alkali burn. Further investigation is needed to determine the optimal timing, duration, and dosage of these treatments.
Topics: Animals; Burns, Chemical; Cornea; Corneal Injuries; Cross-Linking Reagents; Eye Burns; Photosensitizing Agents; Rabbits; Riboflavin; Vascular Endothelial Growth Factor A; Wound Healing
PubMed: 34435926
DOI: 10.1080/02713683.2021.1971722 -
International Journal of Molecular... Dec 2022is a dangerous hospital pathogen primarily due to its ability to form biofilms on different abiotic and biotic surfaces. The present study investigated the effect of...
is a dangerous hospital pathogen primarily due to its ability to form biofilms on different abiotic and biotic surfaces. The present study investigated the effect of riboflavin- and chlorophyllin-based antimicrobial photodynamic therapy, performed with near-ultraviolet or blue light on the viability of bacterial cells in biofilms and their structural stability, also determining the extent of photoinduced generation of intracellular reactive oxygen species as well as the ability of to form biofilms after the treatment. The efficacy of antimicrobial photodynamic therapy was compared with that of light alone and the role of the photosensitizer type on the photosensitization mechanism was demonstrated. We found that the antibacterial effect of riboflavin-based antimicrobial photodynamic therapy depends on the ability of photoactivated riboflavin to generate intracellular reactive oxygen species but does not depend on the concentration of riboflavin and pre-incubation time before irradiation. Moreover, our results suggest a clear interconnection between the inactivation efficiency of chlorophyllin-based antimicrobial photodynamic therapy and the sensitivity of biofilms to used light. In summary, all the analyzed results suggest that riboflavin-based antimicrobial photodynamic therapy and chlorophyllin-based antimicrobial photodynamic therapy have the potential to be applied as an antibacterial treatment against biofilms or as a preventive measure against biofilm formation.
Topics: Acinetobacter baumannii; Reactive Oxygen Species; Anti-Infective Agents; Anti-Bacterial Agents; Photochemotherapy; Biofilms; Riboflavin
PubMed: 36614160
DOI: 10.3390/ijms24010722 -
Ophthalmology Jan 2023
Topics: Humans; Photosensitizing Agents; Photochemotherapy; Cross-Linking Reagents; Keratoconus; Corneal Stroma; Riboflavin; Ultraviolet Rays
PubMed: 35773078
DOI: 10.1016/j.ophtha.2022.04.025 -
Advanced Science (Weinheim,... Mar 2023Photodynamic therapy (PDT) is a light triggered therapy by producing reactive oxygen species (ROS), but traditional PDT may suffer from the real-time illumination that...
Photodynamic therapy (PDT) is a light triggered therapy by producing reactive oxygen species (ROS), but traditional PDT may suffer from the real-time illumination that reduces the compliance of treatment and cause phototoxicity. A supramolecular photoactive G-quartet based material is reported, which is self-assembled from guanosine (G) and 4-formylphenylboronic acid/1,8-diaminooctane, with incorporation of riboflavin as a photocatalyst to the G4 nanowire, for post-irradiation photodynamic antibacterial therapy. The G4-materials, which exhibit hydrogel-like properties, provide a scaffold for loading riboflavin, and the reductant guanosine for the riboflavin for phototriggered production of the therapeutic H O . The photocatalytic activity shows great tolerance against room temperature storage and heating/cooling treatments. The riboflavin-loaded G4 hydrogels, after photo-irradiation, are capable of killing gram-positive bacteria (e.g., Staphylococcus aureus), gram-negative bacteria (e.g., Escherichia coli), and multidrug resistant bacteria (methicillin-resistant Staphylococcus aureus) with sterilization ratio over 99.999%. The post-irradiated hydrogels also exhibit great antibacterial activity in the infected wound of the rats, revealing the potential of this novel concept in the light therapy.
Topics: Rats; Animals; Methicillin-Resistant Staphylococcus aureus; Photochemotherapy; Escherichia coli; Riboflavin; Anti-Bacterial Agents; Wound Infection; Hydrogels
PubMed: 36709479
DOI: 10.1002/advs.202206851 -
Microbiology Spectrum Feb 2023Oropharyngeal candidiasis (OPC), which has a high incidence in immunocompromised and denture stomatitis patients, is commonly caused by Candida albicans infection and in...
Oropharyngeal candidiasis (OPC), which has a high incidence in immunocompromised and denture stomatitis patients, is commonly caused by Candida albicans infection and in some cases develops into disseminated candidiasis throughout the throat and esophagus, resulting in high mortality. New drugs are needed to combat OPC because of the limited treatment options currently available and increasing resistance to existing drugs. Here, we confirmed that riboflavin (RF), a cofactor of flavin adenine mononucleotide and flavin adenine dinucleotide, has broad-spectrum anti- activity. The formation of C. albicans hyphae and biofilm was inhibited by RF. Mechanistically, RF disrupted membrane and cell wall integrity, as well as promoting reactive oxygen species and pyruvate accumulation. Furthermore, RF targeted multiple essential pathways via functional disruption of thiamine and RF metabolic pathways, central carbon metabolism, and ribosome metabolism. Similar to the results , the inhibitory effect of RF on C. albicans hyphae was confirmed in a mouse model of OPC. Moreover, after 5 consecutive days of intraperitoneal injection, RF exhibited therapeutic efficacy, as demonstrated by phenotype investigation, the fungal burden, and histopathological analysis. These findings revealed that RF exerts a multifaceted anti- effect and has potential benefits in the treatment of OPC. species are common pathogens in fungal infections, causing mucosal infection and invasive infection in immunodeficient patients. Given the limited classes of drugs and resistance to these drugs, new antifungal agents need to be developed. Drug repurposing is a potential method for antifungal drug development. This study demonstrated that riboflavin (RF) exhibited broad-spectrum anti- activity. RF affected multiple targets involving the membrane and cell wall integrity, the accumulation of reactive oxygen species and pyruvate, and the altered metabolic pathways in C. albicans. Moreover, RF exhibited efficacy in the treatment of C. albicans in an oropharyngeal candidiasis mouse model. Taken together, the antifungal activity and the promising clinical application of RF were highlighted.
Topics: Animals; Mice; Candida albicans; Antifungal Agents; Reactive Oxygen Species; Candidiasis, Oral; Candidiasis; Candida; Ribosomes; Riboflavin; Microbial Sensitivity Tests
PubMed: 36625571
DOI: 10.1128/spectrum.03801-22 -
Journal of Biophotonics Dec 2022Theranostics is an emerging therapeutic paradigm of personalized medicine; the term refers to the simultaneous integration of therapy and diagnostics. In this work,...
Theranostics is an emerging therapeutic paradigm of personalized medicine; the term refers to the simultaneous integration of therapy and diagnostics. In this work, theranostic-guided corneal cross-linking was performed on 10 human sclero-corneal tissues. The samples were soaked with 0.22% riboflavin formulation and underwent 9 minutes UV-A irradiance at 10 mW/cm using theranostic device, which provided both a measure of corneal riboflavin concentration and a theranostic score estimating treatment efficacy in real time. A three-element viscoelastic model was developed to fit the deformation response of the cornea to air-puff excitation of dynamic tonometry and to calculate the mean corneal stiffness parameter before and after treatment. Significant correlation was found between the theranostic score and the increase in mean corneal stiffness (R = 0.80; P < .001). Accuracy and precision of the theranostic score in predicting the induced corneal tissue stiffening were both 90%. The riboflavin concentration prior to starting the UV-A photo-therapy phase was the most important variable to allow corneal cross-linking to be effective. Theranostic UV-A light mediated imaging and therapy enables the operator to adopt a precise approach for achieving highly predictable biomechanical strengthening on individual corneas.
Topics: Humans; Keratoconus; Corneal Cross-Linking; Precision Medicine; Cross-Linking Reagents; Cornea; Riboflavin; Ultraviolet Rays; Photosensitizing Agents
PubMed: 36059083
DOI: 10.1002/jbio.202200218