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1.
Nanomaterials (Basel) ; 14(12)2024 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-38921893

RESUMO

Tetrahedral amorphous carbon (taC) is a hydrogen-free carbon with extensive properties such as hardness, optical transparency, and chemical inertness. taC coatings have attracted much attention in recent times, as have coatings doped with a noble metal. A known antimicrobial metal agent, silver (Ag), has been used as a dopant in taC, with different Ag concentrations on the Ti64 coupons using a hybrid filtered cathodic vacuum arc (FCVA) and magnetron sputtering system. The physiochemical properties of the coated surface were investigated using spectroscopic and electron microscopy techniques. A doping effect of Ag-taC on biofilm formation was investigated and found to have a significant effect on the bacterial-biofilm-forming bacteria Staphylococcus aureus and Pseudomonas aeruginosa depending on the concentration of Ag. Further, the effect of coated and uncoated Ag-taC films on a pathogenic bacterium was examined using SEM. The result revealed that the Ag-taC coatings inhibited the biofilm formation of S. aureus. Therefore, this study demonstrated the possible use of Ag-taC coatings against biofilm-related complications on medical devices and infections from pathogenic bacteria.

2.
Environ Res ; 258: 119408, 2024 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-38876417

RESUMO

The use of algae for value-added product and biorefining applications is enchanting attention among researchers in recent years due to its remarkable photosynthetic ability, adaptability, and capacity to accumulate lipids and carbohydrates. Algae biomass, based on its low manufacturing costs, is relatively renewable, sustainable, environmentally friendly and economical in comparison with other species. High production rate of algae provides a unique opportunity for its conversion to biochar with excellent physicochemical properties, viz. high surface area and pore volume, high adsorption capacity, abundant functional groups over surface, etc. Despite several potential algal-biochar, a detailed study on its application for removal of emerging contaminants from wastewater is limited. Therefore, this technical review is being carried out to evaluate the specific elimination of inorganic and organic pollutants from wastewater, with a view to assessing adsorption performances of biochar obtained from various algae species. Species-specific adsorption of emerging pollutants from wastewater have been discussed in the present review. The promising methods like pyrolysis, gasification, dry and wet torrefaction for the production of algae biochar are highlighted. The strategies include chemical and structural modifications of algae biochar for the removal of toxic contaminants have also been considered in the current work. The overall aim of this review is to confer about the synthesis, technological advancements, delineation and application of algae biochar for the treatment of wastewater.

3.
Artigo em Inglês | MEDLINE | ID: mdl-38478317

RESUMO

A promising alternative for effective carbon capture has been found in microalgae because of their high photosynthetic capacity and quick growth. The carbon concentration mechanism of many microalgae is heavily reliant on the enzyme carbonic anhydrase (CA), which catalyze the production of bicarbonate from carbon dioxide. In this study, microalgal samples were collected, characterized, and cultured under controlled conditions for their optimal growth of cultures I-IX. The CA activity was investigated using a standard method; the Wilbur-Anderson assay was used to calculate CA activity in microalgal cultures. The comparative study was then used to measure the activity rate of the collected microalgae. Among the tested, culture I, VI, and IX showed a high enzyme activity rate of 4.15, 4.0, and 4.2 µg·mL-1, respectively. To determine the rate of carbon dioxide hydration, the method involved tracking the pH change in a reaction mixture. In addition, genetic analysis facilitates the identification of key genes involved in CA activity and other metabolic processes, which enhance the knowledge of microalgal physiology, and enables genetic engineering efforts in the future studies. Overall, this investigation emphasizes the significance of studying unknown microalgal culture and their potential CA activity for industrial and bio-energy applications.

4.
Int J Pharm ; 655: 124052, 2024 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-38552751

RESUMO

Antimicrobial peptides (AMPs) are promising novel agents for targeting a wide range of pathogens. In this study, microalgal peptides derived from native microalgae were incorporated into polycaprolactone (PCL) with ƙ-Carrageenan (ƙ-C) forming nanofibers using the electrospinning method. The peptides incorporated in the nanofibers were characterized by fourier infrared spectroscopy, thermogravimetric analysis, scanning electron microscopy (SEM), and contact angle measurement. The results showed that peptides with molecular weights < 10 kDa, when loaded into nanofibers, exhibited lower wettability. The SEM analysis revealed a thin, smooth, interconnected bead-like structures. The antimicrobial activity of the electrospun nanofibers was evaluated through disc diffusion, and minimum inhibitory activity against Escherichia coli (MTTC 443), and Staphylococcus aureus (MTTC 96), resulting in zones of inhibition of 24 ± 0.5 mm and 14 ± 0.5 mm, respectively. The in vitro biocompatibility of the synthesized nanofibers was confirmed using in HEK 293 cell lines with an increased cell viability. Interestingly, the fibers also exhibited a significant wound-healing properties when used in vitro scratch assays. In conclusion, algal peptides incorporated with PCL/ ƙ-C were found to exhibit antimicrobial and biocompatible biomaterials for wound healing applications.


Assuntos
Anti-Infecciosos , Microalgas , Nanofibras , Humanos , Carragenina , Nanofibras/química , Células HEK293 , Antibacterianos/farmacologia , Poliésteres/química , Cicatrização , Anti-Infecciosos/farmacologia , Peptídeos/farmacologia
5.
Chemosphere ; 344: 140337, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37797901

RESUMO

Polycyclic aromatic hydrocarbons (PAHs) are pervasive in the atmosphere and are one of the emerging pollutants that cause harmful effects in living systems. There are some natural and anthropogenic sources that can produce PAHs in an uncontrolled way. Several health hazards associated with PAHs like abnormality in the reproductive system, endocrine system as well as immune system have been explained. The mutagenic or carcinogenic effects of hydrocarbons in living systems including algae, vertebrates and invertebrates have been discussed. For controlling PAHs, biodegradation has been suggested as an effective and eco-friendly process. Microalgae-based biosorption and biodegradation resulted in the removal of toxic contaminants. Microalgae both in unialgal form and in consortium (with bacteria or fungi) performed good results in bioaccumulation and biodegradation. In the present review, we highlighted the general information about the PAHs, conventional versus advanced technology for removal. In addition microalgae based removal and toxicity is discussed. Furthermore this work provides an idea on modern scientific applications like genetic and metabolic engineering, nanomaterials-based technologies, artificial neural network (ANN), machine learning (ML) etc. As rapid and effective methods for bioremediation of PAHs. With several pros and cons, biological treatments using microalgae are found to be better for PAH removal than any other conventional technologies.


Assuntos
Poluentes Ambientais , Microalgas , Hidrocarbonetos Policíclicos Aromáticos , Animais , Biodegradação Ambiental , Microalgas/metabolismo , Hidrocarbonetos Policíclicos Aromáticos/análise , Poluentes Ambientais/análise , Bactérias/metabolismo
6.
Int J Biol Macromol ; 253(Pt 2): 126592, 2023 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-37659486

RESUMO

Chitosan is a bio-polymer made up of repeating units of N-acetyl glucosamine and glucosamine joined together by (1-4)-glycosidic linkages. Various bioresources have been used to develop bioactive materials that have a wide range of applications in different fields, including industry and medicine. Borassus flabellifer is a well-known source of chitin in the sub-Indian continent and is used in digestion, pharmaceuticals, and other applications. Chitin can be extracted from B. flabellifer fruit shells through demineralization and deproteinization and then converted into chitosan through deacetylation. This study aimed to investigate the biological activity of chitosan extracted from B. flabellifer fruit shells and to analyze its molecular structure using FT-IR analysis. Results showed the presence of NH, OH, and CO stretching, indicating the presence of various functional groups in chitosan. Scanning electron microscopic study revealed the topography of the chitosan. Well-diffusion and MIC tests showed that chitosan exhibited activity against E. coli and S. aureus. The chitosan extract also exhibited potential antioxidant polymer by scavenging free radicals.


Assuntos
Quitosana , Quitosana/farmacologia , Quitosana/química , Antioxidantes/farmacologia , Espectroscopia de Infravermelho com Transformada de Fourier , Escherichia coli , Staphylococcus aureus , Quitina/química , Antibacterianos/farmacologia , Glucosamina
7.
J Clin Med ; 12(18)2023 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-37762724

RESUMO

Tinnitus is the perception of abnormal sounds in the ears or head without external auditory stimulation. While classical test theory is often used in tinnitus questionnaire development, it has limitations in assessing item characteristics. Item response theory (IRT) offers more precise individual ability estimations and identifies key and less important items, making it superior for reliable measurement tools. This study investigated the suitability of the Korean version of the Tinnitus Handicap Inventory (K-THI) as a patient-reported outcome measure (PROM) for clinical trials. Using Rasch analysis based on IRT, we evaluated K-THI's measurement of tinnitus-related disability in 545 patients (40.4% men, 59.6% women). Five items (2, 7, 8, 19, and 24) did not fit the Rasch model, yet a unidimensional scale and good fit for person and item data emerged (person: 0.89; item: 0.98). The three-point rating scale in K-THI proved suitable. IRT allowed precise evaluation of K-THI's properties, vital for reliable PROMs in patient-centered care. Our findings highlight IRT's role in questionnaire development, contributing to the advancement of PROMs.

8.
Artigo em Inglês | MEDLINE | ID: mdl-37642923

RESUMO

In this study, a fungal species was isolated from rhizospheric soil and identified as Penicillium sp. by ITS sequencing. The Penicillium sp. has been screened for the biosurfactant production, viz., haemolytic activity, oil spreading assay and emulsification index. The biosurfactant from cell-free supernatant was extracted using acid precipitation followed by solvent-solvent extraction. The physiochemical properties of the extracted biosurfactant were analysed using FTIR; the major peaks that show at 1720 cm-1, 1531 cm-1, 1419 cm-1, 1251 cm-1 and 1010 cm-1 correspond to aliphatic chains, sugars and ester carbonyl groups. The fatty acids present in the extracted biosurfactant were analysed using GCMS, in which a molecular mass of 256 and 284 m/z showed the presence of n-hexadecenoic acid and octadecanoic acid respectively which indicate the presence of rhamnolipid, which is a major biosurfactant. The biosurfactant extracted from Penicllium sp. demonstrated antibacterial activity against Escherichia coli and Staphylococcus aureus. In future perspectives, the biosurfactant extracted from the isolated species holds great potential as a broad-spectrum antibacterial agent and could be utilized in various healthcare applications.

9.
Pharmaceutics ; 15(2)2023 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-36839785

RESUMO

Biofilm-related nosocomial infections may cause a wide range of life-threatening infections. In this regard, Pseudomonas aeruginosa biofilm is becoming a serious health burden due to its capability to develop resistance to natural and synthetic drugs. The utilization of nanoparticles that inhibit biofilm formation is one of the major strategies to control infections caused by biofilm-forming pathogens. Hydroxyapatite (HA) is a synthetic ceramic material having properties similar to natural bones. Herein, a co-precipitation method followed by microwave treatment was used to synthesize HA nanoparticles (HANPs). The resulting HANPs were characterized using X-ray diffraction and transmission electron microscopy. Then, their antibiofilm properties against P. aeruginosa ATCC 10145 were examined in vitro. The needle-shaped HANPs were 30 and 90 nm long in width and length, respectively. The synthesized HANPs inhibited the biofilm formation of P. aeruginosa ATCC 10145 in a concentration-dependent manner, which was validated by light and confocal laser scanning microscopy. Hence, this study demonstrated that HANPs could be used to control the biofilm-related infections of P. aeruginosa.

10.
Arch Microbiol ; 205(3): 86, 2023 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-36757622

RESUMO

Bacillus cereus is a rod-shaped, gram-positive, motile, and ß-hemolytic soil bacterium. B. cereus is an opportunistic pathogen, often responsible for human foodborne illness that is caused by ingestion of starchy foods with symptoms of diarrhea and vomiting. Among the numerous amylolytic enzymes in the genome of the pathogen, the one annotated as a putative neopullulanase (NPase) was cloned and its biochemical properties were characterized in this study. The corresponding gene encoded an enzyme of 586 amino acids with a predicted molecular mass of 68.25 kDa. The putative NPase shared 43.7-59.2% of identity with NPases, cyclomaltodextrinases (CDases), and maltogenic amylases from various bacteria, but shared very low similarity with other amylolytic enzymes of B. cereus. The optimal pH and temperature of the enzyme was 6.5 and 37 â„ƒ, respectively. The enzyme activity was decreased by the cations tested in this study and completely inhibited by Co2+ and Cu2+. The purified enzyme showed substrate preference in the order of α-CD > ß-CD > starch > maltodextrin > γ-CD and hydrolyzed them mainly to maltose. However, it did not hydrolyze maltose, pullulan, and glycogen. The enzyme was designated herein as a CDase of B. cereus (BcCDase). Furthermore, the enzyme could transfer the sugars released from CDs and maltotriose to acceptor molecules. BcCDase was likely to be involved in the maltodextrin metabolism in B. cereus.


Assuntos
Bacillus cereus , Maltose , Sequência de Aminoácidos , Bacillus cereus/genética , Bacillus cereus/metabolismo , Glicosídeo Hidrolases/metabolismo , Maltose/metabolismo , Especificidade por Substrato
11.
Arch Microbiol ; 205(2): 78, 2023 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-36723711

RESUMO

The mdxR gene located upstream of mdxD, encoding a maltogenic amylase, has been annotated as a member of LacI-type transcriptional regulator in Bacillus subtilis 168 but its function has not been investigated yet. In this study, expression pattern of the mdxR promoter (PmdxR) and effects of mdxR were investigated to elucidate the function of mdxR. Expression of PmdxR was monitored by the ß-galactosidase activity expressed from the PmdxR-lacZ fusion integrated at the amyE locus on the chromosome. The promoter was induced by starch, ß-cyclomaltodextrin, or maltose at early exponential phase and kept expressed until late stationary phase. However, it was repressed by glucose, sucrose, or glycerol, suggesting that it was under catabolite repression. Furthermore, interactions of MdxR and Spo0A to the DNA fragment carrying PmdxR or PmdxD were detected by mobility-shift assay, implying that MdxR was a novel transcription regulator for both genes, which were regulated also by Spo0A. The mdxR mutant impaired the expressions of mdxD and malL (encoding an α-glucosidase); degraded accumulated glycogen slower than the wild type and the mdxD mutant. Both of the mdxR and the mdxD mutants formed more endospores (50.95% and 47.10%) than the wild type (23.90%). Enhanced sporulation by these mutations could be of industrial interest where sporulation or endospores of B. subtilis matters. These results indicate that MdxR functions as a transcriptional regulator for mdxR, mdxD, and other genes in the gene cluster that is related to the maltose/maltodextrin metabolism. MdxR and MdxD are also involved in glycogen metabolism and sporulation, tentatively by modulating the net energy balance in the cell.


Assuntos
Bacillus subtilis , Maltose , Bacillus subtilis/genética , Bacillus subtilis/metabolismo , Maltose/metabolismo , Regiões Promotoras Genéticas , Glicogênio/metabolismo , Metabolismo dos Carboidratos/genética , Esporos Bacterianos/genética , Esporos Bacterianos/metabolismo , Proteínas de Bactérias/metabolismo , Regulação Bacteriana da Expressão Gênica , Transcrição Gênica
12.
Carbohydr Polym ; 302: 120341, 2023 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-36604041

RESUMO

The biocomposites of hydroxypropyl methylcellulose (HPMC)/silver nanoparticles (AgNPs) were synthesized using the solution plasma process (SPP). HPMC/AgNPs were synthesized in 1-5 % HPMC solutions using silver electrodes. UV-Vis spectroscopy showed a peak near 400 nm and the peak increased as the concentration of HPMC and discharge time increased. FTIR analysis indicated no change in the chemical structure of the HPMC based biocomposites. Spherical shaped AgNPs with size ranges about 2-18 nm and well dispersed in the porous HPMC matrices with fringed edges were observed by TEM and SEM/EDS analyses. The synthesized biocomposites were found to be thermo-stable by TGA analysis. The inhibition zones of bacterial growth formed by the HPMC/AgNPs biocomposites were in the range of 8-14.3 mm; minimal inhibition concentrations, in the range of 10-15 µg·mL-1 for Gram-negative bacteria; 25-30 µg·mL-1 for Gram-positive bacteria. The biocomposites were non-toxic to the HEK293 cells up to 125 µg·mL-1. The results indicated that the synthesis of antibacterial agents in the HPMC matrix using silver electrodes via SPP would be an efficient and safe way for the development of biopolymer based antimicrobials and wound healing biomaterials.


Assuntos
Nanopartículas Metálicas , Humanos , Nanopartículas Metálicas/química , Derivados da Hipromelose , Prata/química , Células HEK293 , Antibacterianos/farmacologia , Antibacterianos/química , Testes de Sensibilidade Microbiana , Extratos Vegetais/química
13.
Appl Biochem Biotechnol ; 195(6): 3699-3718, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35349084

RESUMO

Palladium nanoparticles (Pd NPs) have been considered as a potential candidate in the field of biomedical applications due to its unique properties such as huge catalytic, hydrogen storage, and sensing behavior. Therefore, Pd NPs have shown to have a significant potential for the development of antimicrobials, wound healing, antioxidant, and anticancer property in recent days. There are plenty of reports that showed superior properties of noble metals. However, only very few studies have been undertaken to explore the advantage of Pd NPs in the field of biomedical applications. This review reports detailed and comprehensive studies comprising of the synthesis, characterization, and potential applications of Pd NPs in biomedicine. This report provides evidences in the literature documented by early researchers to understand the potential applications of Pd NPs to be explored in various fields.


Assuntos
Nanopartículas Metálicas , Paládio , Antibacterianos , Antioxidantes , Catálise
14.
Arch Microbiol ; 204(11): 668, 2022 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-36220932

RESUMO

Glycogen is important for transmission of V. vulnificus undergoing disparate environments of nutrient-rich host and nutrient-limited marine environment. The malZ gene of V. vulnificus encoding a maltodextrin glucosidase was cloned and over-expressed in E. coli to investigate its roles in glycogen/maltodextrin metabolism in the pathogen. The malZ gene encoded a protein with a predicted molecular mass of 70 kDa. The optimal pH and temperature of MalZ was 7.0 and 37 °C, respectively. MalZ hydrolyzed maltodextrin to glucose and maltose most efficiently, while hydrolyzed other substrates such as starch, maltose, ß-cyclomaltodextrin, and glycogen less efficiently. The activity was enhanced greatly by Mn2+. It also exhibited transglycosylation activity toward excessive maltotriose. The malZ knock-out mutant accumulated 2.3-5.6-fold less glycogen than the wild type when excessive maltodextrin or glucose was added to LB medium, while it accumulated more glycogen than the wild type (3.5-fold) in the presence of excessive maltose. Growth and glycogen accumulation of the mutant were retarded most significantly in the M63 minimal medium supplemented with 0.5% maltodextrin. Side chain length distributions of glycogen molecules were varied by the malZ mutation and types of the excessive carbon source. Based on the results, MalZ of V. vulnificus was likely to be involved in maltose/maltodextrin metabolism, thereby balancing synthesis of glycogen and energy generation in the cell. The bacterium seemed to have multiple and unique pathways for glycogen metabolism according to carbon sources.


Assuntos
Proteínas de Escherichia coli , Vibrio vulnificus , Carbono/metabolismo , Escherichia coli/metabolismo , Proteínas de Escherichia coli/genética , Glucose/metabolismo , Glucosidases/metabolismo , Glicogênio/metabolismo , Glicosídeo Hidrolases/genética , Maltose/metabolismo , Polissacarídeos , Amido/metabolismo
15.
Appl Biochem Biotechnol ; 194(11): 5580-5593, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-35793061

RESUMO

The antimicrobial peptides derived from microalgae have attracted a huge attention due to the insufficient availability of effective drugs from the natural resources. In this study, the enzymatic hydrolysate of protein derived from Limnospira maxima was prepared using pepsin under optimized conditions. The peptides with range of 10 kDa were isolated and purified using the Ultra membrane filtration, SDS-PAGE, and TLC. Furthermore, the peptide sequence was identified and characterized by MALDI-TOF mass spectrometry in which an algal peptide, KLENCNYAVELGK showed a strong signal at 466.68 m/z among seven peptides derived from the pepsin hydrolysate. The FT-IR spectroscopic study confirmed the presence of a characteristic functional group of amino acids in the sequence. The algal derived peptide showed antibacterial properties against Escherichia coli (27 ± 0.5 mm) and Staphylococcus aureus (14 mm ± 0.5). This study paves a way to explore the antibacterial peptide from a novel species, L. maxima (MZ26519) evident to utilize for the novel drug to overcome the conventional approach.


Assuntos
Proteínas de Algas , Pepsina A , Pepsina A/química , Espectroscopia de Infravermelho com Transformada de Fourier , Antibacterianos/química , Peptídeos/farmacologia , Peptídeos/química , Escherichia coli , Aminoácidos/farmacologia
16.
J Microbiol ; 60(4): 375-386, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35157220

RESUMO

Vibrio vulnificus MO6-24/O has three genes annotated as debranching enzymes or pullulanase genes. Among them, the gene encoded by VVMO6_03032 (vvde1) shares a higher similarity at the amino acid sequence level to the glycogen debranching enzymes, AmyX of Bacillus subtilis (40.5%) and GlgX of Escherichia coli (55.5%), than those encoded by the other two genes. The vvde1 gene encoded a protein with a molecular mass of 75.56 kDa and purified Vvde1 efficiently hydrolyzed glycogen and pullulan to shorter chains of maltodextrin and maltotriose (G3), respectively. However, it hydrolyzed amylopectin and soluble starch far less efficiently, and ß-cyclodextrin (ß-CD) only rarely. The optimal pH and temperature of Vvde1 was 6.5 and 25°C, respectively. Vvde1 was a cold-adapted debranching enzyme with more than 60% residual activity at 5°C. It could maintain stability for 2 days at 25°C and 1 day at 35°C, but it destabilized drastically at 40°C. The Vvde1 activity was inhibited considerably by Cu2+, Hg2+, and Zn2+, while it was slightly enhanced by Co2+, Ca2+, Ni2+, and Fe2+. The vvde1 knock-out mutant accumulated more glycogen than the wild-type in media supplemented with 1.0% maltodextrin; however, the side chain length distribution of glycogen was similar to that of the wild-type except G3, which was much more abundant in the mutant. Therefore, Vvde1 seemed to debranch glycogen with the degree of polymerization 3 (DP3) as the specific target branch length. Virulence of the pathogen against Caenorhabditis elegans was attenuated significantly by the vvde1 mutation. These results suggest that Vvde1 might be a unique glycogen debranching enzyme that is involved in both glycogen utilization and shaping of glycogen molecules, and contributes toward virulence of the pathogen.


Assuntos
Sistema da Enzima Desramificadora do Glicogênio , Vibrio vulnificus , Amilopectina/metabolismo , Glicogênio/metabolismo , Sistema da Enzima Desramificadora do Glicogênio/química , Sistema da Enzima Desramificadora do Glicogênio/genética , Sistema da Enzima Desramificadora do Glicogênio/metabolismo , Vibrio vulnificus/metabolismo , Virulência/genética
17.
Microb Pathog ; 160: 105189, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34530072

RESUMO

The outbreak of the novel coronavirus (COVID-19) has affected millions of lives and it is one of the deadliest viruses ever known and the effort to find a cure for COVID-19 has been very high. The purpose of the study was to investigate the anti-COVID effect from the peptides derived from microalgae. The peptides from microalgae exhibit antimicrobial, anti-allergic, anti-hypersensitive, anti-tumor and immune-modulatory properties. In the In silico study, 13 cyanobacterial specific peptides were retrieved based on the extensive literature survey and their structures were predicted using Discovery Studios Visualizer. The spike protein of the novel COVID19 was retrieved from PDB (6LU7) and further molecular docking was done with the peptides through CDOCKER. The five peptides were bound clearly to the spike protein (SP) and their inhibitory effect towards the SP was promising among 13 peptides were investigated. Interestingly, LDAVNR derived from S.maxima have excellent binding and interaction energy showed -113.456 kcal/mol and -71.0736 kcal/mol respectively to target SP of COVID. The further investigation required for the in vitro confirmation of anti-COVID from indigenous microalgal species for the possible remedy in the pandemic.


Assuntos
Antivirais/química , Microalgas , Peptídeos/química , SARS-CoV-2/efeitos dos fármacos , Glicoproteína da Espícula de Coronavírus/antagonistas & inibidores , Simulação por Computador , Microalgas/química , Simulação de Acoplamento Molecular
18.
Appl Biochem Biotechnol ; 193(12): 4097-4112, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34449041

RESUMO

The objective of the study was to depolymerize alginate into short-length oligoalginates, adopting the simple solution plasma process (SPP) technique, for successful use in free radical scavenging and growth promotion in cell culture and agricultural practices. Alginate at various concentrations was depolymerized to oligoalginates using SPP by discharging for various times. The depolymerization into oligoalginates was proved by DNS, TLC, FT-IR, and HPAEC analyses and caused decrease in viscosity. Oligoalginates derived from 0.5% alginate (100 mg∙mL-1) showed the highest antioxidant activities in vitro. The oligoalginates enhanced growth of the human embryonic kidney (HEK293) cells to significant levels in a concentration-dependent manner without any extent of toxicity. The oligoalginates also promoted growth of lettuce. Thus, SPP is a powerful technique to break down alginate into oligoalginates that can be utilized as a free radical scavenger and as a growth promoter of animal cells and agricultural plants.


Assuntos
Alginatos , Oligossacarídeos , Alginatos/química , Alginatos/farmacologia , Relação Dose-Resposta a Droga , Células HEK293 , Humanos , Oligossacarídeos/química , Oligossacarídeos/farmacologia
19.
PLoS One ; 15(9): e0239327, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32946498

RESUMO

In older adults with subjective memory complaints (SMCs), featuring a decline in memory but not exhibiting problems during medical examinations and objective memory tests, the weak links between nodes evident in the word retrieval process can be a primary factor for predicting mild cognitive impairment and dementia. This study examined the frequency of the "Tip-of-the-Tongue" (ToT) phenomenon according to age and subjective memory complaints of older adults, and identified differences in the resolution method using sequential cues. A celebrity naming task was performed on older adults (aged 50 to 79) with SMCs (n = 30) and without SMCs (n = 30), comparing the frequency of the ToT phenomenon and in resolution methods. We found that, even if our subjects with SMCs obtained normal results in the objective neuropsychology test, they experienced a significantly higher frequency of the ToT phenomenon than those without SMCs. In addition, subjects with SMCs showed a significantly lower rate of resolution, both spontaneous and following a syllabic cue, compared to those without SMCs. SMCs can be a very early marker of degenerative diseases causing cognitive dysfunction, and thus the selection of appropriate tools for early detection of SMCs is important. The proper naming task may sensitively detect subclinical symptoms of SMCs in subjects who are not classified as patients with cognitive impairments on general neuropsychological test. In addition, this task can identify weak connections between semantic and phonological nodes due to changes in the neural region of older adults with SMCs.


Assuntos
Transtornos da Memória/fisiopatologia , Rememoração Mental/fisiologia , Idoso , Envelhecimento/psicologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
20.
Elife ; 92020 04 09.
Artigo em Inglês | MEDLINE | ID: mdl-32271147

RESUMO

Phosphate overload contributes to mineral bone disorders that are associated with crystal nephropathies. Phytate, the major form of phosphorus in plant seeds, is known as an indigestible and of negligible nutritional value in humans. However, the mechanism and adverse effects of high-phytate intake on Ca2+ and phosphate absorption and homeostasis are unknown. Here, we show that excessive intake of phytate along with a low-Ca2+ diet fed to rats contributed to the development of crystal nephropathies, renal phosphate wasting, and bone loss through tubular dysfunction secondary to dysregulation of intestinal calcium and phosphate absorption. Moreover, Ca2+ supplementation alleviated the detrimental effects of excess dietary phytate on bone and kidney through excretion of undigested Ca2+-phytate, which prevented a vicious cycle of intestinal phosphate overload and renal phosphate wasting while improving intestinal Ca2+ bioavailability. Thus, we demonstrate that phytate is digestible without a high-Ca2+ diet and is a risk factor for phosphate overloading and for the development of crystal nephropathies and bone disease.


Assuntos
Osso e Ossos/metabolismo , Cálcio da Dieta/efeitos adversos , Cálcio/metabolismo , Minerais/metabolismo , Ração Animal/análise , Animais , Dieta/efeitos adversos , Feminino , Masculino , Fosfatos , Fósforo/metabolismo , Ácido Fítico/farmacologia , Ratos Sprague-Dawley , Insuficiência Renal Crônica/metabolismo , Fatores de Risco
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