Evaluation of Stain Removal Efficacy and Color Stability of Three Different Dentifrices on Artificially Stained Enamel Surface-An In Vitro Study.

AIM: The aim of the present study was to assess the stain removal ability and color stability of three distinct dentifrices on artificially stained enamel surface. MATERIALS AND METHODS: This study included 75 intact, healthy premolars free of dental caries that were extracted during orthodontic therapy. The samples were allowed to dry for 6 hours after being submerged in the prepared tea solution for roughly 18 hours every day. Then this procedure was repeated for seven successive days. All samples were randomly divided into three experimental groups with 25 samples in each group. Group I: control dentifrice, group II: dentifrice containing hydrogen peroxide, group III: dentifrice containing papain and bromelain. A specially designed toothbrushing simulator was used to brush every sample in the relevant group. Using a spectrophotometer and a measurement program, color measurement was evaluated after staining process after 4 weeks and 8 weeks of teeth cleaning. Using a profilometer, the surface roughness values (Ra) were assessed. RESULTS: After 8 weeks of brushing of stained samples, the color stability was better in dentifrice containing hydrogen peroxide (1.14 ± 0.11) followed by dentifrice containing papain and bromelain (1.22 ± 0.08) and control group (1.30 ± 0.09). And after 8 weeks of brushing of stained samples, the surface roughness was more in dentifrice containing hydrogen peroxide (0.237 ± 0.02) followed by dentifrice containing papain and bromelain (0.229 ± 0.13) and control group (0.207 ± 0.05). CONCLUSION: The present study concluded that the dentifrice containing hydrogen peroxide showed a superior whitening effect on the stained enamel surface than dentifrice containing papain and bromelain and control dentifrice. CLINICAL SIGNIFICANCE: The development of various dentifrice products has been greatly aided by the increased demand for an improved esthetic appearance. Teeth's natural color and any external stains that could accumulate on the tooth surface combine to determine a tooth's color. Additionally, the use of whitening dental pastes to remove external stains has grown in favor. With the development of these whitening toothpastes, dentifrices' ability to lessen or eliminate extrinsic dental stains has increased. How to cite this article: Mishra D, Kamath DG, Alagla M, et al. Evaluation of Stain Removal Efficacy and Color Stability of Three Different Dentifrices on Artificially Stained Enamel Surface-An In Vitro Study. J Contemp Dent Pract 2024;25(1):68-71.

Investigation of the peptides with calcium chelating capacity in hydrolysate derived from spent hen meat.

Calcium peptide chelates are developed as efficient supplements for preventing calcium deficiency. Spent hen meat (SHM) contains a high percentage of proteins but is generally wasted due to the disadvantages such as hard texture. We chose the underutilized SHM to produce peptides to bind calcium by proteolysis and aimed to investigate chelation between calcium and peptides in hydrolysate for a sustainable purpose. The optimized proteolysis conditions calculated from the result of response surface methodology for two-step hydrolysis were 0.30% (wenzyme/wmeat) for papain with a hydrolysis time of 3.5 h and 0.18% (wenzyme/wmeat) for flavourzyme with a hydrolysis time of 2.8 h. The enzymatic hydrolysate (EH) showed a binding capacity of 63.8 ± 1.8 mg calcium/g protein. Ethanol separation for EH improved the capacity up to a higher value of 68.6 ± 0.6 mg calcium/g protein with a high association constant of 420 M-1 (25°C) indicating high stability. The separated fraction with a higher amount of Glu, Asp, Lys, and Arg had higher calcium-binding capacity, which was related to the number of ─COOH and ─NH2 groups in peptide side chains according to the result from amino acid analysis and Fourier transform infrared spectroscopy. Two-step enzymatic hydrolysis and ethanol separation were an efficient combination to produce peptide mixtures derived from SHM with high calcium-binding capacity. The high percentage of hydrophilic amino acids in the separated fraction was concluded to increase calcium-binding capacity. This work provides foundations for increasing spent hen utilization and developing calcium peptide chelates based on underutilized meat.

Identification of Phytochemicals from Arabian Peninsula Medicinal Plants as Strong Binders to SARS-CoV-2 Proteases (3CLPro and PLPro) by Molecular Docking and Dynamic Simulation Studies.

We provide promising computational (in silico) data on phytochemicals (compounds 1-10) from Arabian Peninsula medicinal plants as strong binders, targeting 3-chymotrypsin-like protease (3CLPro) and papain-like proteases (PLPro) of SARS-CoV-2. Compounds 1-10 followed the Lipinski rules of five (RO5) and ADMET analysis, exhibiting drug-like characters. Non-covalent (reversible) docking of compounds 1-10 demonstrated their binding with the catalytic dyad (CYS145 and HIS41) of 3CLPro and catalytic triad (CYS111, HIS272, and ASP286) of PLPro. Moreover, the implementation of the covalent (irreversible) docking protocol revealed that only compounds 7, 8, and 9 possess covalent warheads, which allowed the formation of the covalent bond with the catalytic dyad (CYS145) in 3CLPro and the catalytic triad (CYS111) in PLPro. Root-mean-square deviation (RMSD), root-mean-square fluctuation (RMSF), and radius of gyration (Rg) analysis from molecular dynamic (MD) simulations revealed that complexation between ligands (compounds 7, 8, and 9) and 3CLPro and PLPro was stable, and there was less deviation of ligands. Overall, the in silico data on the inherent properties of the above phytochemicals unravel the fact that they can act as reversible inhibitors for 3CLPro and PLPro. Moreover, compounds 7, 8, and 9 also showed their novel properties to inhibit dual targets by irreversible inhibition, indicating their effectiveness for possibly developing future drugs against SARS-CoV-2. Nonetheless, to confirm the theoretical findings here, the effectiveness of the above compounds as inhibitors of 3CLPro and PLPro warrants future investigations using suitable in vitro and in vivo tests.

Effects of different concentrations of bromelain and papain enzymes on shear bond strength of composite resin to deep dentin using an etch-and-rinse adhesive system.

BACKGROUND: The dentin substrate can be modified by proteolytic agents, which may affect the bonding strength of adhesive systems to the treated dentin surface. Papain, a cysteine protease enzyme with antibacterial and anti-inflammatory properties, can be used for deproteinization of dentin. An alternative deproteinizing enzyme is bromelain. OBJECTIVES: This study aimed to evaluate the impact of deproteinization on the shear bond strength (SBS) of composite resin to deep dentin using different concentrations of bromelain and papain. MATERIAL AND METHODS: Sixty upper premolars were extracted and randomly divided into 5 groups (n = 12 per group). In all groups, the dentin surface was etched with 37% phosphoric acid. Group 1 did not receive any enzyme treatment, group 2 was treated with a 10% papain solution, group 3 was treated with a 15% papain solution, group 4 was treated with a 6% bromelain solution, and group 5 was treated with a 10% bromelain solution. After applying an etch-and-rinse adhesive system, the specimens were restored with composite resin and the SBS was measured. RESULTS: Statistically significant differences were found between groups 2 and 3 (10% papain and 15% papain, p = 0.004), groups 2 and 4 (10% papain and 6% bromelain, p = 0.017), groups 4 and 5 (6% bromelain and 10% bromelain, p = 0.021), and groups 3 and 5 (15% papain and 10% bromelain, p = 0.005). CONCLUSIONS: Deproteinization with papain and bromelain at different concentrations after acid etching did not affect the SBS of composite resin to deep dentin when using an etch-and-rinse adhesive system. However, the group deproteinized with 15% papain demonstrated a higher SBS than the group deproteinized with 10% papain, and the group deproteinized with 6% bromelain showed a higher SBS compared to the group deproteinized with 10% bromelain.

Comparison of prediction models for soy protein isolate hydrolysates bitterness built using sensory, spectrofluorometric and chromatographic data from varying enzymes and degree of hydrolysis.

The bitterness of soy protein isolate hydrolysates prepared using five proteases at varying degree of hydrolysis (DH) and its relation to physicochemical properties, i.e., surface hydrophobicity (H0), relative hydrophobicity (RH), and molecular weight (MW), were studied and developed for predictive modelling using machine learning. Bitter scores were collected from sensory analysis and assigned as the target, while the physicochemical properties were assigned as the features. The modelling involved data pre-processing with local outlier factor; model development with support vector machine, linear regression, adaptive boosting, and K-nearest neighbors algorithms; and performance evaluation by 10-fold stratified cross-validation. The results indicated that alcalase hydrolysates were the most bitter, followed by protamex, flavorzyme, papain, and bromelain. Distinctive correlation results were found among the physicochemical properties, influenced by the disparity of each protease. Among the features, the combination of RH-MW fitted various classification models and resulted in the best prediction performance.

Influence of yeast growth conditions and proteolytic enzymes on the amino acid profiles of yeast hydrolysates: Implications for taste and nutrition.

This study investigated the effects of aerobic and anaerobic growth and proteolytic enzymes on the amino acid content of yeast hydrolysates in relation to taste and nutrition. Saccharomyces cerevisiae ATCC5574 was grown under fed-batch aerobic or batch anaerobic conditions. Intracellular glutamic acid (Glu) concentrations were 18-fold higher in aerobic yeast. Hydrolysis with papain and alkaline protease released more amino acids (AA) than simple autolysis or hydrolysis with bromelain, most significantly when applied to aerobic yeast (∼2-fold increase). Autolysates and bromelain hydrolysates from aerobic yeast had low levels of bitter and essential AAs, with high levels of umami Glu. Papain and alkaline protease hydrolysates of aerobic yeast had high levels of umami, bitter and essential AAs. Autolysates/hydrolysates from anaerobic yeast had moderate, high, and low levels of bitter, essential and umami AAs. Selection of both yeast growth conditions and hydrolysis enzyme can manipulate the free AA profile and yield of hydrolysates.

Evaluation of the microleakage of class V composite restoration after cavity treatment with Erbium, CO2 lasers, Papain, and Bromelain enzymes.

OBJECTVES: Different surface preparation and treatment methods may have dissimilar effects on the microleakage of composite resin. This study was conducted to determine the deproteinizing effect of 10% bromelain enzyme, 10% papain enzyme, CO2 , and erbium-YAG laser in regard to decrease in the microleakage of composite restorations. MATERIALS AND METHODS: Thirty teeth were selected and 60 class V cavities were prepared on the lingual and buccal sides. They were divided into six groups (n = 10): Group 1, phosphoric acid gel; Group 2, bromelain enzyme 10%; Group 3, papain enzyme 10%; Group 4, mixed papain and bromelain enzymes 10%; Group 5, CO2 laser; and Group 6, erbium-YAG laser. They were stored in basic fuchsine and dye penetration was evaluated. Kruskal-Wallis and Mann-Whitney tests were used for statistical analysis, p < 0.05 RESULTS: In both occlusal and gingival margins, comparison of microleakage between groups 1, 2, 3, 4, and 5 showed no significant differences (p = 1) and group 6 had a significant difference with other groups (p ˂ 0.001). CONCLUSIONS: Microleakage of composite resin in the dentin surface was not affected significantly using either bromelain or papain 10% enzymes or erbium laser. However, CO2 laser had a negative effect on the enamel and dentin margins and increased the microleakage. Erbium laser showed a better effect than enzymes on microleakage.

Characterization of the structure, antioxidant activity and hypoglycemic activity of soy (Glycine max L.) protein hydrolysates.

This study aimed to hydrolyze soy isolate protein (SPI) using five enzymes (alcalase, pepsin, trypsin, papain, and bromelain) in order to obtain five enzymatic hydrolysates and to elucidate the effect of enzymes on structural and biological activities of the resulting hydrolysates. The antioxidant and hypoglycemic activities of the soy protein isolate hydrolysates (SPIEHs) were evaluated through in silico analysis, revealing that the alcalase hydrolysate exhibited the highest potential, followed by the papain and bromelain hydrolysates. Subsequently, the degree of hydrolysis (DH), molecular weight distribution (MWD), amino acid composition, structure, antioxidant activities, and hypoglycemic activity in vitro of SPIEHs were analyzed. After enzymatic treatment, the particle size, polymer dispersity index (PDI), ζ-potentials, ß-sheet content and α-helix content of SPIEHs was decreased, and the maximum emission wavelength of all SPIEHs exhibited red-shifted, which all suggesting the structure of SPIEHs was unfolded. More total amino acids (TAAs), aromatic amino acids (AAAs), and hydrophobic amino acids (HAAs) were found in alcalase hydrolysate. For 1,1-Diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, metal ion chelating activity, α-glucosidase inhibitory activity and α-amylase inhibitory activity, alcalase hydrolysate had the lowest IC50; alcalase hydrolysate and papain hydrolysate had the lowest IC50 for hydroxyl radical scavenging activity. Physiological activity of SPIEHs was evaluated thoroughly by 5-Axe cobweb charts, and the results revealed that alcalase hydrolysate exhibited the greatest biological activities.

Antiviral Effect of 5'-Arylchalcogeno-3-aminothymidine Derivatives in SARS-CoV-2 Infection.

The understanding that zidovudine (ZDV or azidothymidine, AZT) inhibits the RNA-dependent RNA polymerase (RdRp) of SARS-CoV-2 and that chalcogen atoms can increase the bioactivity and reduce the toxicity of AZT has directed our search for the discovery of novel potential anti-coronavirus compounds. Here, the antiviral activity of selenium and tellurium containing AZT derivatives in human type II pneumocytes cell model (Calu-3) and monkey kidney cells (Vero E6) infected with SARS-CoV-2, and their toxic effects on these cells, was evaluated. Cell viability analysis revealed that organoselenium (R3a-R3e) showed lower cytotoxicity than organotellurium (R3f, R3n-R3q), with CC50 ≥ 100 µM. The R3b and R3e were particularly noteworthy for inhibiting viral replication in both cell models and showed better selectivity index. In Vero E6, the EC50 values for R3b and R3e were 2.97 ± 0.62 µM and 1.99 ± 0.42 µM, respectively, while in Calu-3, concentrations of 3.82 ± 1.42 µM and 1.92 ± 0.43 µM (24 h treatment) and 1.33 ± 0.35 µM and 2.31 ± 0.54 µM (48 h) were observed, respectively. The molecular docking calculations were carried out to main protease (Mpro), papain-like protease (PLpro), and RdRp following non-competitive, competitive, and allosteric inhibitory approaches. The in silico results suggested that the organoselenium is a potential non-competitive inhibitor of RdRp, interacting in the allosteric cavity located in the palm region. Overall, the cell-based results indicated that the chalcogen-zidovudine derivatives were more potent than AZT in inhibiting SARS-CoV-2 replication and that the compounds R3b and R3e play an important inhibitory role, expanding the knowledge about the promising therapeutic capacity of organoselenium against COVID-19.

Complexation of Bromelain, Ficin, and Papain with the Graft Copolymer of Carboxymethyl Cellulose Sodium Salt and N-Vinylimidazole Enhances Enzyme Proteolytic Activity.

This study investigates the features of interactions between cysteine proteases (bromelain, ficin, and papain) and a graft copolymer of carboxymethyl cellulose sodium salt with N-vinylimidazole. The objective is to understand the influence of this interactions on the proteolytic activity and stability of the enzymes. The enzymes were immobilized through complexation with the carrier. The interaction mechanism was examined using Fourier-transform infrared spectroscopy and flexible molecular docking simulations. The findings reveal that the enzymes interact with the functional groups of the carrier via amino acid residues, resulting in the formation of secondary structure elements and enzyme's active sites. These interactions induce modulation of active site of the enzymes, leading to an enhancement in their proteolytic activity. Furthermore, the immobilized enzymes demonstrate superior stability compared to their native counterparts. Notably, during a 21-day incubation period, no protein release from the conjugates was observed. These results suggest that the complexation of the enzymes with the graft copolymer has the potential to improve their performance as biocatalysts, with applications in various fields such as biomedicine, pharmaceutics, and biotechnology.

Identification of bromelain subfamily proteases encoded in the pineapple genome.

Papain (aka C1A) family proteases, including bromelain enzymes, are widespread across the plant kingdom and play critical regulatory functions in protein turnover during development. The proteolytic activity exhibited by papain family proteases has led to their increased usage for a wide range of cosmetic, therapeutic, and medicinal purposes. Bromelain enzymes, or bromelains in short, are members of the papain family that are specific to the bromeliad plant family. The only major commercial extraction source of bromelain is pineapple. The importance of C1A family and bromelain subfamily proteases in pineapple development and their increasing economic importance led several researchers to utilize available genomic resources to identify protease-encoding genes in the pineapple genome. To date, studies are lacking in screening bromelain genes for targeted use in applied science studies. In addition, the bromelain genes coding for the enzymes present in commercially available bromelain products have not been identified and their evolutionary origin has remained unclear. Here, using the newly developed MD2 v2 pineapple genome, we aimed to identify bromelain-encoding genes and elucidate their evolutionary origin. Orthologous and phylogenetic analyses of all papain-family proteases encoded in the pineapple genome revealed a single orthogroup (189) and phylogenetic clade (XIII) containing the bromelain subfamily. Duplication mode and synteny analyses provided insight into the origin and expansion of the bromelain subfamily in pineapple. Proteomic analysis identified four bromelain enzymes present in two commercially available bromelain products derived from pineapple stem, corresponding to products of four putative bromelain genes. Gene expression analysis using publicly available transcriptome data showed that 31 papain-family genes identified in this study were up-regulated in specific tissues, including stem, fruit, and floral tissues. Some of these genes had higher expression in earlier developmental stages of different tissues. Similar expression patterns were identified by RT-qPCR analysis with leaf, stem, and fruit. Our results provide a strong foundation for future applicable studies on bromelain, such as transgenic approaches to increase bromelain content in pineapple, development of bromelain-producing bioreactors, and studies that aim to determine the medicinal and/or therapeutic viability of individual bromelain enzymes.

Decolorization of porcine hemoglobin hydrolysates: The role of peptide characteristics and pH values.

The unpleasant color caused by heme limits the utilization of hemoglobin as a food ingredient. Enzymatic hydrolysis has been used to decolorize hemoglobin, but the underlying mechanisms are poorly understood. The aim of this study was to investigate the decolorization efficiency of porcine hemoglobin using different enzymes and final pH values, and to elucidate their influence on decolorization. Based on higher yields and better decolorization, hemoglobin hydrolysates produced by papain, bromelain, savinase, and protease A were further studied. Compared to hydrolysates by savinase and protease A, a higher proportion of histidine-containing peptides was responsible for better decolorization by papain and bromelain. For all hydrolysates, a moderate reduction in pH to 4.0-5.0 facilitated decolorization of the hydrolysates. Similar peptide profiles of hydrolysates from the same enzyme treatment reflected that pH mainly affected the precipitation of the heme-containing fraction through heme-heme interaction rather than heme-peptide interaction. Overall, this study sheds light on the use of enzymatic hydrolysis to remove the heme group from hemoglobin. PRACTICAL APPLICATION: Slaughterhouses produce tons of protein-rich blood each year. Due to the presence of the heme group in hemoglobin, blood has a dark red color and metallic taste, making it generally unacceptable for consumers. This study provided information on the decolorization of porcine hemoglobin by removing the heme fraction, which should facilitate the utilization of decolored hemoglobin hydrolysates as nutritional food ingredients.

Identifying Drug Candidates for COVID-19 with Large-Scale Drug Screening.

Papain-like protease (PLpro) is critical to COVID-19 infection. Therefore, it is a significant target protein for drug development. We virtually screened a 26,193 compound library against the PLpro of SARS-CoV-2 and identified several drug candidates with convincing binding affinities. The three best compounds all had better estimated binding energy than those of the drug candidates proposed in previous studies. By analyzing the docking results for the drug candidates identified in this and previous studies, we demonstrate that the critical interactions between the compounds and PLpro proposed by the computational approaches are consistent with those proposed by the biological experiments. In addition, the predicted binding energies of the compounds in the dataset showed a similar trend as their IC50 values. The predicted ADME and drug-likeness properties also suggested that these identified compounds can be used for COVID-19 treatment.

Evaluation of new L-amino acids triethanolammonium salts usability for controlling protease activity.

Twenty new triethanolammonium amino acid salts (TEA AA) have been prepared from triethanolammonium hydroxide and L-amino acids. The physicochemical properties of TEA AA depended on the applied amino acid. Five of the synthesised salts, i.e. mono- and bis-salts of L-glutamic acid, L-aspartic acid, and TEA salt of l-glutamine were solids with melting points between 127.32 °C to 171.51 °C. The other TEA AA exhibited glass transition temperatures from -68.45 °C for TEA Ser to -6.27 °C for TEA Trp and were assigned as amino acid ionic liquids (AAILs). The TEA His was characterised by the highest thermal stability, with an average temperature of 5 % weight loss at 186.4 °C, whereas the lowest stability was determined for TEA Asp (107.5 °C). The developed salts were tested as reaction medium additives for proteolytic enzymes (papain, subtilisin, bromelain). Most AAILs showed an inhibitory effect on tested proteases but with different mechanisms related to the enzyme substrate specificity and structural diversity. The TEA Ser was the most effective competitive inhibitor (Ki = 0.24 10-4 mol/L) for bromelain, while TEA Val uncompetitive inhibitor for papain (Ki = 0.25 10-4 mol/L). The developed TEA AA salts exhibit potential as enzyme-controlling agents for use in industrial processes.

In silico and in vitro studies on inhibitors for SARS-CoV-2 non-structural proteins with dual herbal combination of Withania somnifera with five rasayana herbs.

Being highly transmissible, severe acute respiratory syndrome coronavirus (SARS-CoV-2) has affected millions of people causing devastating global impact and has also not slowed down even after vaccination. The emerges of new strains has made more concerns than the original one. We need a new therapeutic approach against the disease. Our comprehensive in silico study investigates dual herbal combinatorial methanolic extracts of W. somnifera (W) alone and with P. emblica (P) (W:P/1:4) , T. sinensis (T) (W:T/1:4), B. monnieri (B) (W:B/1:1), O. basilicum (O) (W:O/1:4), A. racemosus (A) (W:A/4:1) for potential four phytochemicals as ligands docked with eight COVID-19 Nonstructural proteins (nsp)-main protease (PDB ID:6LU7), papain-like protease (6WUU), helicase ADP (2XZL), N7-methyltransferase (5C8S), endoribonuclease (6WLC), 2'O-methyltransferase (6WVN), RNA dependent RNA polymerase (6M71), and 3Cprotease (6YNQ) along with Remdesivir and Hydroxychloroquine. Ligands from W:P/1:4 showed remarkable docking score (-9.01 kcal/mol) 6M71-(8E,11E,14E)-eicosa-8,11,14-trienoicacidmethylester (EIS) and (-9.99 kcal/mol) 6YNQ-N-[(E)-[4-[(2-methoxydibenzofuran-3-yl)amino]-4-oxobutan-2-ylidene]amino] 4nitrobenzamide (MET). Further, MD simulations were studied for 100 ns and showed the complexes were flexible, stable in the binding pockets of the receptors, and MM-PBSA analysis determined high binding energy of -129.673 ± 15.284 and -134.594 ± 7.085 for 6M71-EIS (Asn496, Lys577, Arg569) and 6YNQ-MET (Cys145, His41). Finally, in vitro JURKAT E6.1 cell lines treated with W:P/1:4 and W:O/1:4 methanolic extracts yielded 44.06 and 31.53 ng/mL levels for interferon alpha to counteract an external stimulus by establishing an antiviral state. Thus, nsp is targeted to design effective antiviral drugs for developing an effective therapeutic approach to combat viral RNA synthesis, processing, and suppression of host immunity.Communicated by Ramaswamy H. Sarma.

Effects of traditional and novel proteolytic agents on tissue dissolution and dentine microhardness.

The study aimed to evaluate the tissue-dissolving ability of papain and bromelain with respect to that of sodium hypochlorite (NaOCl) at the temperatures of 25°C and 60°C. The study also assessed the effects of these proteolytic agents on radicular dentine microhardness. Warming NaOCl, papain and bromelain solutions resulted in significant tissue dissolution at all time intervals (p < 0.001). At 60°C, bromelain showed significantly higher tissue weight loss at every time interval when compared to NaOCl (p < 0.001). All of the three organic tissue dissolvents reduced the microhardness at 1 hr when compared to their respective baseline values. The reduction in microhardness from the baseline reading was statistically significant only in the papain group at 30 min (p = 0.018) and at 60 min (p = 0.03) when compared to the control group. Hence it was concluded that bromelain exerted superior tissue dissolution action, especially when warmed, with minimal effect on dentine microhardness.

Therapeutic potential of metal ions for COVID-19: insights from the papain-like protease of SARS-CoV-2.

Coronaviruses have been responsible for multiple challenging global pandemics, including coronavirus disease 2019 (COVID-19), which is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Papain-like protease (PLpro), one of two cysteine proteases responsible for the maturation and infectivity of SARS-CoV-2, processes and liberates functional proteins from the viral polyproteins and cleaves ubiquitin and ISG15 modifications to inhibit innate immune sensing. Consequently, PLpro is an attractive target for developing COVID-19 therapies. PLpro contains a zinc-finger domain important for substrate binding and structural stability. However, the impact of metal ions on the activity and biophysical properties of SARS-CoV-2 PLpro has not been comprehensively studied. Here, we assessed the impacts of metal ions on the catalytic activity of PLpro. Zinc had the largest inhibitory effect on PLpro, followed by manganese. Calcium, magnesium, and iron had smaller or no effects on PLpro activity. EDTA at a concentration of 0.5 mM was essential for PLpro activity, likely by chelating trace metals that inhibit PLpro. IC50 values for ZnCl2, ZnSO4, and MnCl2 of 0.42 ± 0.02 mM, 0.35 ± 0.01 mM, and 2.6 ± 0.3 mM were obtained in the presence of 0.5 mM EDTA; in the absence of EDTA, the estimated IC50 of ZnCl2 was 14 µM. Tryptophan intrinsic fluorescence analysis confirmed the binding of zinc and manganese to PLpro, and differential scanning calorimetry revealed that zinc but not manganese reduced ΔHcal of PLpro. The results of this study provide a reference for further work targeting PLpro to prevent and treat COVID-19.

In Silico Approach of Glycinin and Conglycinin Chains of Soybean By-Product (Okara) Using Papain and Bromelain.

This study explores utilization of a sustainable soybean by-product (okara) based on in silico approach. In silico approaches, as well as the BIOPEP database, PeptideRanker database, Peptide Calculator database (Pepcalc), ToxinPred database, and AllerTop database, were employed to evaluate the potential of glycinin and conglycinin derived peptides as a potential source of bioactive peptides. These major protein precursors have been found as protein in okara as a soybean by-product. Furthermore, primary structure, biological potential, and physicochemical, sensory, and allergenic characteristics of the theoretically released antioxidant peptides were predicted in this research. Glycinin and α subunits of ß-conglycinin were selected as potential precursors of bioactive peptides based on in silico analysis. The most notable among these are antioxidant peptides. First, the potential of protein precursors for releasing bioactive peptides was evaluated by determining the frequency of occurrence of fragments with a given activity. Through the BIOPEP database analysis, there are several antioxidant bioactive peptides in glycinin and ß and α subunits of ß-conglycinin sequences. Then, an in silico proteolysis using selected enzymes (papain, bromelain) to obtain antioxidant peptides was investigated and then analyzed using PeptideRanker and Pepcalc. Allergenic analysis using the AllerTop revealed that all in silico proteolysis-derived antioxidant peptides are probably nonallergenic peptides. We also performed molecular docking against MPO (myeloperoxidases) for this peptide. Overall, the present study highlights that glycinin and ß and α subunits of ß-conglycinin could be promising precursors of bioactive peptides that have an antioxidant peptide for developing several applications.

A utilização de fitoterápicos no tratamento de feridas diabéticas: relato de caso / The use of phytotherapics in the treatment of diabetic wounds: a case report / El uso de fitoterapéuticos en el tratamiento de heridas diabéticas: reporte de un caso

Objetivo: O presente estudo tem como finalidade avaliar a efetividade do ácido hialurônico associado à papaína na cicatrização de feridas em pacientes diabéticos. Método: Trata-se de um estudo descritivo do tipo estudo de caso. Este estudo foi realizado no Município de Duque de Caxias, no período de 17 de junho a 20 de julho de 2022. A coleta de dados foi realizada por meio de visitas domiciliares com anotações diárias da evolução do caso, e acompanhamento fotográfico da evolução da lesão. O paciente assinou o termo de consentimento livre esclarecido, conforme determinação 196/96 do MS. A avaliação da ferida foi realizada pelo enfermeiro responsável pelo caso, e os curativos eram realizados periodicamente pela equipe de enfermagem.Resultados: Paciente do sexo masculino, 51 anos, com Diabetes Mellitus, insulinodependente, sem aderir adequadamente ao tratamento; apresentando lesão crônica, decorrente de amputação em Pé esquerdo, a qual ocorreu em setembro de 2019, estando desde então com curso desfavorável. Considerações finais: foi constatado que após o início do uso de fitoterápicos, houve a aceleração do processo de cicatrização, e que a ação destes, foi de fundamental eficácia para a completa cicatrização da ferida, em um espaço bem curto de tempo. E também é muito importante levarmos em conta o baixo custo dos fitoterápicos em relação aos demais medicamentos, e a melhoria da qualidade de vida e de autoestima do paciente com o desfecho do caso.

Objective: The present study aims to evaluate the effectiveness of hyaluronic acid and papain in the wound healing of diabetic patients. Method: This is a descriptive study of the case study type. This study was conducted in the municipality of Duque de Caxias, from the 17thof June 2022 to the 20thof July 2022. Data were collected through home visits with daily notes on the case evolution, and photographic follow-up of the evolution of the lesion. The patient signed the free and informed consent term, according to the resolution 196/96 of the Ministry of Health. The wound was assessed by the nurse in charge of the case, and dressings were changed periodically by the nursing staff. Results: A 51-year-old male insulin-dependent patient with Diabetes Mellitus without properly adhering to treatment; with a chronic injury, due to the amputation of the left foot, which had occurred in September 2019, having an unfavorable course since then. Final considerations: it has been found that after the patient started using herbal medicine, the healing process was accelerated, and their action was fundamental do the effectiveness of the complete healing of the wound, in a very short time. It is also important to consider the low cost of herbal medicines when compared to other medications, and the improved quality of life and self-esteem of the patient with the outcome of the case.

Objetivo: El presente estudio tiene por objeto evaluar la efectividad del ácidohialurónico asociado a la papaína para la cicatrización de heridas en pacientes diabéticos. Método: Se trata de un estudio descriptivo del tipo estudio de caso. Este estudio se llevó a cabo en el Municipio de Duque de Casias, RJ, Brasil, durante el período de 17 de junio a 20 de julio de2022. La recolección de los datos fue efectuada a través de visitas domiciliarias con anotaciones diarias de la evolución del caso, así como también de acompañamiento fotográfico de la evolución de la lesión. El paciente firmó un documento de consentimiento libre y aclarado, conforme la determinación 196/96 del Ministério de Salud. La evaluación de la herida fue llevada a cabo por el enfermero responsable por el caso y los curativos fueron realizados periódicamente por el equipo de enfermería. Resultados: Paciente del sexo masculino, 51 años, con diabetes Mellitus, insulinodependiente, sin adherir adecuadamente al tratamiento, presentando lesión crónica resultante de amputación en el pié izquierdo, la cual ocurrió en septiembre de 2019 y desde entonces en curso desfavorable. Consideraciones finales: Se constató que después de iniciar el uso de productos fitoterapéuticos ocurrió una aceleración del proceso de cicatrización y que la acción de dichos productos fue de fundamental eficacia para la completa cicatrización de la herida en un periodo bastante corto de tiempo. También es muy importante considerar tanto el bajo costo de los productos fitoterapéuticos en comparación a los demás medicamentos, así como también el mejoramiento de la calidad de vida y de la autoestima del paciente con el resultado del caso.

Inhibition of Nematocyst Discharge from Pelagia noctiluca (Cnidaria: Scyphozoa)-Prevention Measures against Jellyfish Stings.

Pelagia noctiluca stings are common in Mediterranean coastal areas and, although the venom is non-lethal, they are painful. Due to its high toxicity and abundance, P. noctiluca is considered a target species for the focus of research on active ingredients to reduce the symptoms of its sting. To determine the effect of 31 substances and formulations on nematocyst discharge, we performed three tests: (1) screening of per se discharge activator solutions, (2) inhibitory test with nematocyst chemical stimulation (5% acetic acid) and (3) inhibitory test quantifying the hemolytic area. Ammonia, barium chloride, bleach, scented ammonia, carbonated cola, lemon juice, sodium chloride and papain triggered nematocyst discharge. All of them were ruled out as potential inhibitors. Butylene glycol showed a reduction in nematocyst discharge, while the formulations of 10% lidocaine in ethanol, 1.5% hydroxyacetophenone in distilled water + butylene glycol, and 3% Symsitive® in butylene glycol inhibited nematocyst discharge. These last results were subsequently correlated with a significant decrease in hemolytic area in the venom assays versus seawater, a neutral solution. The presented data represent a first step in research to develop preventive products for jellyfish stings while at the same time attempting to clarify some uncertainties about the role of various topical solutions in P. noctiluca first-aid protocols.