Targeting proprotein convertase subtilisin/kexin type 9 (PCSK9): from bench to bedside.

Proprotein convertase subtilisin/kexin type 9 (PCSK9) has evolved as a pivotal enzyme in lipid metabolism and a revolutionary therapeutic target for hypercholesterolemia and its related cardiovascular diseases (CVD). This comprehensive review delineates the intricate roles and wide-ranging implications of PCSK9, extending beyond CVD to emphasize its significance in diverse physiological and pathological states, including liver diseases, infectious diseases, autoimmune disorders, and notably, cancer. Our exploration offers insights into the interaction between PCSK9 and low-density lipoprotein receptors (LDLRs), elucidating its substantial impact on cholesterol homeostasis and cardiovascular health. It also details the evolution of PCSK9-targeted therapies, translating foundational bench discoveries into bedside applications for optimized patient care. The advent and clinical approval of innovative PCSK9 inhibitory therapies (PCSK9-iTs), including three monoclonal antibodies (Evolocumab, Alirocumab, and Tafolecimab) and one small interfering RNA (siRNA, Inclisiran), have marked a significant breakthrough in cardiovascular medicine. These therapies have demonstrated unparalleled efficacy in mitigating hypercholesterolemia, reducing cardiovascular risks, and have showcased profound value in clinical applications, offering novel therapeutic avenues and a promising future in personalized medicine for cardiovascular disorders. Furthermore, emerging research, inclusive of our findings, unveils PCSK9's potential role as a pivotal indicator for cancer prognosis and its prospective application as a transformative target for cancer treatment. This review also highlights PCSK9's aberrant expression in various cancer forms, its association with cancer prognosis, and its crucial roles in carcinogenesis and cancer immunity. In conclusion, this synthesized review integrates existing knowledge and novel insights on PCSK9, providing a holistic perspective on its transformative impact in reshaping therapeutic paradigms across various disorders. It emphasizes the clinical value and effect of PCSK9-iT, underscoring its potential in advancing the landscape of biomedical research and its capabilities in heralding new eras in personalized medicine.

Antiplatelet mechanism of a subtilisin-like serine protease from Solanum tuberosum (StSBTc-3).

The aims of this study are to characterize the antiplatelet activity of StSBTc-3, a potato serine protease with fibrino (geno) lytic activity, and to provide information on its mechanism of action. The results obtained show that StSBTc-3 inhibits clot retraction and prevents platelet aggregation induced by thrombin, convulxin, and A23187. Platelet aggregation inhibition occurs in a dose-dependent manner and is not affected by inactivation of StSBTc-3 with the inhibitor of serine proteases phenylmethylsulfonyl fluoride (PMSF). In addition, StSBTc-3 reduces fibrinogen binding onto platelets. In-silico calculations show a high binding affinity between StSBTc-3 and human α2bß3 integrin suggesting that the antiplatelet activity of StSBTc-3 could be associated with the fibronectin type III domain present in its amino acid sequence. Binding experiments show that StSBTc-3 binds to α2bß3 preventing the interaction between α2bß3 and fibrinogen and, consequently, inhibiting platelet aggregation. StSBTc-3 represents a promising compound to be considered as an alternative to commercially available drugs used in cardiovascular therapies.

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.

PEER simplified lipid guideline 2023 update: Prevention and management of cardiovascular disease in primary care.

OBJECTIVE: To update the 2015 clinical practice guideline and provide a simplified approach to lipid management in the prevention of cardiovascular disease (CVD) for primary care. METHODS: Following the Institute of Medicine's Clinical Practice Guidelines We Can Trust, a multidisciplinary, pan-Canadian guideline panel was formed. This panel was represented by primary care providers, free from conflicts of interest with industry, and included the patient perspective. A separate scientific evidence team performed evidence reviews on statins, ezetimibe, proprotein convertase subtilisin-kexin type 9 inhibitors, fibrates, bile acid sequestrants, niacin, and omega-3 supplements (docosahexaenoic acid with eicosapentaenoic acid [EPA] or EPA ethyl ester alone [icosapent]), as well as on 11 supplemental questions. Recommendations were finalized by the guideline panel through use of the Grading of Recommendations Assessment, Development and Evaluation methodology. RECOMMENDATIONS: All recommendations are presented in a patient-centred manner designed with the needs of family physicians and other primary care providers in mind. Many recommendations are similar to those published in 2015. Statins remain first-line therapy for both primary and secondary CVD prevention, and the Mediterranean diet and physical activity are recommended to reduce cardiovascular risk (primary and secondary prevention). The guideline panel recommended against using lipoprotein a, apolipoprotein B, or coronary artery calcium levels when assessing cardiovascular risk, and recommended against targeting specific lipid levels. The team also reviewed new evidence pertaining to omega-3 fatty acids (including EPA ethyl ester [icosapent]) and proprotein convertase subtilisin-kexin type 9 inhibitors, and outlined when to engage in informed shared decision making with patients on interventions to lower cardiovascular risk. CONCLUSION: These updated evidence-based guidelines provide a simplified approach to lipid management for the prevention and management of CVD. These guidelines were created by and for primary health care professionals and their patients.

Immobilization and docking studies of Carlsberg subtilisin for application in poultry industry.

Carlsberg subtilisin from Bacillus licheniformis PB1 was investigated as a potential feed supplement, through immobilizing on bentonite for improving the growth rate of broilers. Initially, the pre-optimized and partially-purified protease was extracted and characterized using SDS-PAGE with MW 27.0 KDa. The MALDI-TOF-MS/MS spectrum confirmed a tryptic peptide peak with m/z 1108.496 referring to the Carlsberg subtilisin as a protein-digesting enzyme with alkaline nature. The highest free enzyme activity (30 U/mg) was observed at 50°C, 1 M potassium phosphate, and pH 8.0. the enhanced stability was observed when the enzyme was adsorbed to an inert solid support with 86.39 ± 4.36% activity retention under 20 optimized conditions. Additionally, the dried immobilized enzyme exhibited only a 5% activity loss after two-week storage at room temperature. Structural modeling (Docking) revealed that hydrophobic interactions between bentonite and amino acids surrounding the catalytic triad keep the enzyme structure intact upon drying at RT. The prominent hygroscopic nature of bentonite facilitated protein structure retention upon drying. During a 46-days study, supplementation of boilers' feed with the subtilisin-bentonite complex promoted significant weight gain i.e. 15.03% in contrast to positive control (p = 0.001).

Multifunctional bioactive properties of hydrolysates from colocynth (Citrullus colocynthis) seeds derived proteins: Characterization and biological properties.

Citrullus colocynthis (Colocynth) has gained a great deal of interest in their applications as indigenous nutraceutical and as a functional food ingredient. The intact colocynth seed protein was enzymatically hydrolyzed using proteolytic enzymes (alcalase, bromelain, and chymotrypsin) at different time intervals of 3, 6, and 9 h. The highest degree of hydrolysis (87.82%) was observed in chymotrypsin derived colocynth seed protein hydrolysates (CSPH) for 9 h. The CSPHs was further investigated through in-vitro assay to explore its potential biological activity such as antioxidant, inhibition of enzymatic marker related to diabetes (DPP-IV, α-glucosidase and α-amylase) and hyperlipidaemia (cholesteryl esterase and pancreatic lipase). Chymotrypsin hydrolysate showed the strongest DPPH (65.7 mM TEAC) and ABTS (525.2 mM TEAC) radical scavenging activity after 6 h of hydrolysis. Moreover, chymotrypsin-treated CSPH for 6 h inhibited cholesteryl esterase (IC50 = 13.68 µg/mL) and pancreatic lipase (IC50 = 14.12 µg/mL) significantly when compared to native protein. Whereas, bromelain and alcalase treated hydrolysate for 6 h effectively inhibited α-glucosidase and α-amylase at an inhibitory concentration of IC50 = 13.27 µg/mL and of IC50 = 17 µg/mL. Overall, the findings indicated that protein hydrolysates exhibited superior biological activity than intact colocynth seed proteins isolate (CSPI) and could be a sustainable source of bioactive peptides.

A comparative analysis of anti-lipidemic potential of soybean (Glycine max) protein hydrolysates obtained from different ripening stages: Identification, and molecular interaction mechanisms of novel bioactive peptides.

This study aims to investigate the potentials of mature (MSPHs) and young (YSPHs) soybean enzymatic protein hydrolysates for the inhibition of pancreatic lipase (PL) and cholesterol esterase (C-Ease) enzymes. Higher proteins degradation levels were recorded with Bromelain compared to Flavourzyme and Alcalase, and upon hydrolysis, improved PL and C-Ease inhibition performances were displayed compared to unhydrolyzed proteins. Afterwards, six PHs with potent anti-lipidemic activities were selected for sequencing using LC-MS QTOF and molecular binding studies. Peptides FPFPRPPHQ, QCCAFEM, FAPEFLK from MSPHs and SFFFPFELPRE, FMYL, PFLL, FPLL, LPHF from YSPHs were predicted to possess potent inhibitory activities against PL. Furthermore, FPFPRPPHQ, FMYL, MMLM from MSPHs, and SFFFPFELPRE from YSPHs were predicted to be potent inhibitors of C-Ease. FPFPRPPHQ and SFFFPFELPRE derived from MSPHs and YSPHs, respectively, demonstrated effective inhibition potentialities against both PL and C-Ease. Therefore, mature and young soybean-derived protein hydrolysates could be recognized as a potential ingredient in the management of hypercholesterolemia.

Loss of hypothalamic Furin affects POMC to proACTH cleavage and feeding behavior in high-fat diet-fed mice.

OBJECTIVE: The hypothalamus regulates feeding and glucose homeostasis through the balanced action of different neuropeptides, which are cleaved and activated by the proprotein convertases PC1/3 and PC2. However, the recent association of polymorphisms in the proprotein convertase FURIN with type 2 diabetes, metabolic syndrome, and obesity, prompted us to investigate the role of FURIN in hypothalamic neurons controlling glucose and feeding. METHODS: POMC-Cre+/- mice were bred with Furinfl/fl mice to generate conditional knockout mice with Furin-deletion in neurons expressing proopiomelanocortin (POMCFurKO), and Furinfl/fl mice were used as controls. POMCFurKO and controls were periodically monitored on both normal chow diet and high fat diet (HFD) for body weight and glucose tolerance by established in-vivo procedures. Food intake was measured in HFD-fed FurKO and controls. Hypothalamic Pomc mRNA was measured by RT-qPCR. ELISAs quantified POMC protein and resulting peptides in the hypothalamic extracts of POMCFurKO mice and controls. The in-vitro processing of POMC was studied by biochemical techniques in HEK293T and CHO cell lines lacking FURIN. RESULTS: In control mice, Furin mRNA levels were significantly upregulated on HFD feeding, suggesting an increased demand for FURIN activity in obesogenic conditions. Under these conditions, the POMCFurKO mice were hyperphagic and had increased body weight compared to Furinfl/fl mice. Moreover, protein levels of POMC were elevated and ACTH concentrations markedly reduced. Also, the ratio of α-MSH/POMC was decreased in POMCFurKO mice compared to controls. This indicates that POMC processing was significantly reduced in the hypothalami of POMCFurKO mice, highlighting for the first time the involvement of FURIN in the cleavage of POMC. Importantly, we found that in vitro, the first stage in processing where POMC is cleaved into proACTH was achieved by FURIN but not by PC1/3 or the other proprotein convertases in cell lines lacking a regulated secretory pathway. CONCLUSIONS: These results suggest that FURIN processes POMC into proACTH before sorting into the regulated secretory pathway, challenging the dogma that PC1/3 and PC2 are the only convertases responsible for POMC cleavage. Furthermore, its deletion affects feeding behaviors under obesogenic conditions.

Phosphocalcic metabolism and the role of vitamin D, vitamin K2, and nattokinase supplementation.

Calcium is involved in bone metabolism, regulation of nerve signaling, and release of neurotransmitters. Phosphorus is a structural component of ATP, participates in metabolic energy regulation, and ensures stability to biological membranes and cells. Vitamin D and vitamin K are important for intestinal absorption and renal excretion of calcium and phosphorus. Vitamin D plays a regulatory role in bone formation, carbohydrate metabolism, immune responses, and cardiovascular regulation. Research has linked vitamin D deficiency to the development of diabetes mellitus, hypertension, cancer, and osteoporosis. Vitamin K has been associated with a reduced risk of osteoporosis, cancer, and cardiovascular diseases (due to improved vascular elasticity). This review highlights the importance of vitamins D and K in the metabolism of calcium and phosphorus and explores various molecular mechanisms that help maintain the system's mineral homeostasis. Moreover, the paper reviews the enzyme nattokinase's role in thrombotic prevention due to its fibrinolytic activity.

Physicochemical, antioxidant and enzymes activities of grape fruit peel and pomace enriched functional drinks.

Experiment was conducted to determine the proximate, minerals, antioxidant capacities and enzymes activities of grape fruit peel and grape fruit pomace along with sensorial evaluation of functional drinks. In this milieu, values of grapefruit peel and pomace powder for moisture, fat, crude protein, carbohydrate, crude fiber, ash, and NFE were recorded as 10.85±1.34,8.9±0.08 , 9.27±0.03, 7.69±0.02, 60.22±2.32, 50.33±2.1, 6.13±0.02, 6.13±0.01, 2.97±0.01 ,2.16±0.01 ,10.56±1.97, 24.97±2.4, respectively whilst in time intervals highest TPC for peel (118.66±8.9) mg/g was observed in 60 min followed by (102.33±7.6) mg/g at 90 min and (82.02±5.5) mg/g at 30 min respectively Whereas, the recorded TPC for pomace at 30, 60 and 90 minute were (112.73±9.1) mg/g has observed in 60 min followed by (97.21±7.9) mg/g at 90 min and (84.55±5.8) mg/g at 30 min respectively. Among the time intervals highest flavonoids contents of peel were at 60 min 52.3±1.9% followed by 52.51±1.7% at 90 min and minimum 50.72±1.4% at 30 min. The highest ABTS value was observed for peel content 248.33±5.6 λg/ml in ethanol extract followed by methanolic extract 212.11±4.4 λg/ml least in water extract 152.5±3.2 λg/ml. The means reviewed FRAP activity highest value for ethanol in peel and pomace were (92.66±5.3 µg/ml Fe2+/g) & (82.47±4.2 µg/ml Fe2+/g) followed by methanol (86.33±4.1 µg/ml Fe2+/g) & (76.83±3.4 µg/ml Fe2+/g) and least in water (66.46±2.2 µg ml Fe2+/g) &(54.24±2.1 µg/ml Fe2+/g) respectively. The color acceptability varied significant effect between 7.49 to 7.55 in T0 to T3. Likewise, storage imparted more significant decline from 7.72 to 7.30 at 0th to 60th days, respectively. The flavor scores were 7.59, 7.41, 7.26 and 7.53 in T0, T1, T2 and T3 respectively. The overall acceptability of drink was significantly increase from initiation (0th) day to termination (60th) day as 7.68 to 6.9.

Insight into the collagen-degrading activity of a serine protease in the latex of Ficus carica cultivar Masui Dauphine.

Ficus carica produces, in addition to the cysteine protease ficin, a serine protease. Earlier study on a serine protease from F. carica cultivar Brown Turkey showed that it specifically degraded collagen. In this study, we characterized the collagenolytic activity of a serine protease in the latex of F. carica cultivar Masui Dauphine. The serine protease degraded denatured, but not undenatured, acid-solubilized type I collagen. It also degraded bovine serum albumin, while the collagenase from Clostridium histolyticum did not. These results indicated that the serine protease in Masui Dauphine is not collagen-specific. The protease was purified to homogeneity by two-dimensional gel electrophoresis, and its partial amino acid sequence was determined by liquid chromatography-tandem mass spectrometry. BLAST searches against the Viridiplantae (green plants) genome database revealed that the serine protease was a subtilisin-like protease. Our results contrast with the results of the earlier study stating that the serine protease from F. carica is collagen-specific.

Selenium accumulation in protein fractions of Tenebrio molitor larvae and the antioxidant and immunoregulatory activity of protein hydrolysates.

Although numerous types of organisms have been used to enrich selenium, a low-cost and efficient organism is yet to be identified. This study aimed to develop a new means of selenium enrichment using Tenebrio molitor larvae. Our results indicated that the total selenium content in larvae was increased 83-fold to 54.21 ± 1.25 µg/g, and of this content, organic selenium accounted for over 97% after feeding the larvae with 20 µg/g of sodium selenite. Selenium was distributed unequally in the protein fraction with following order: alkali-soluble protein-bound selenium (36.32%) > salt-soluble protein-bound selenium (19.41%) > water-soluble protein-bound selenium (17.03%) > alcohol-soluble protein-bound selenium (3.21%). Additionally, 81% of the selenium within the soluble proteins was distributed in subunits possessing molecular weights of <40 kDa. After hydrolysis by alcalase, the protein hydrolysate of selenium-enriched larvae possessing 75% selenium recovery exhibited stronger antioxidant and immunoregulatory activities than those of regular larvae.

Cleavage of a pathogen apoplastic protein by plant subtilases activates host immunity.

The plant apoplast is a harsh environment in which hydrolytic enzymes, especially proteases, accumulate during pathogen infection. However, the defense functions of most apoplastic proteases remain largely elusive. We show here that a newly identified small cysteine-rich secreted protein PC2 from the potato late blight pathogen Phytophthora infestans induces immunity in Solanum plants only after cleavage by plant apoplastic subtilisin-like proteases, such as tomato P69B. A minimal 61 amino acid core peptide carrying two key cysteines, conserved widely in most oomycete species, is sufficient for PC2-induced cell death. Furthermore, we showed that Kazal-like protease inhibitors, such as EPI1, produced by P. infestans prevent PC2 cleavage and dampen PC2 elicited host immunity. This study reveals that cleavage of pathogen proteins to release immunogenic peptides is an important function of plant apoplastic proteases.

Acute and Subchronic Toxicities and Safety Pharmacology Studies of a Bacillus Subtilisin in Dogs.

Subtilisin NAT, a Bacillus subtilisin, is widely applied as a functional food and considered to be one of the most exploitable potential oral thrombolytic agents. Subtilisin QK, another Bacillus subtilisin, is a serine protease fermented by Bacillus subtilis 02 and has a better thrombolytic effect. Therefore, subtilisin QK is typically used for evaluating the safety of Bacillus subtilisins. Here, we conduct several good laboratory practice (GLP)-compliant studies in non-rodent animal, i.e., in Beagle dogs, including acute toxicity, subchronic toxicity, and safety pharmacology studies. No adverse effects were evident in the acute and 28-d subchronic toxicity studies at doses up to 40000 FU/kg and 16000 FU/kg/d, respectively. In evaluating the pharmacological safety of up to 2000FU/kg subtilisin QK, we found no significant differences between the electrocardiograms, blood pressures, and respiration of beagle dogs. These findings suggest the safety of Bacillus subtilisin, providing reliable pharmacological and toxicological data for its development and popularization as a functional food and drug.

Antioxidant activity and peptidomic analysis of porcine liver hydrolysates using alcalase, bromelain, flavourzyme and papain enzymes.

Antioxidant peptides are increasingly being recognized as food additives due to their effects on body human, regulating in vivo oxidative stress against oxidation of lipids and proteins. Meat by-products are rich sources of protein that can be employed for this purpose. Specifically, porcine liver can be used to prepare hydrolysates with antioxidant activity employing proteolytic enzymes such as alcalase, bromelain, papain and flavourzyme. In this study, the antioxidant activity of these four porcine liver hydrolysates was evaluated by 2,2-diphenyl-1-picrylhydrazyl (DPPH), ((2,2-azinobis-(3-ethyl-benzothiazoline-6-sulphonate) (ABTS), Ferric reducing antioxidant power assay (FRAP) and Oxygen radical absorbance capacity assay (ORAC) assays and the identification of bioactive peptides was carried out by SWATH-MS technology. According to the SDS-PAGE pattern, the proteolysis index and the free amino acids amount, the protein degradation was clearly different among the studied enzymes. Indeed, alcalase enzyme produced the release of small peptides, meanwhile flavourzyme produced higher level of free amino acids. The heatmap analysis showed a peptidomic pattern more differentiated for alcalase than for the other enzymes. The peptides most abundant and correlated with antioxidant capacity were APAAIGPYSQAVLVDR from uncharacterized protein, GLNQALVDLHALGSAR, ALFQDVQKPSQDEWGK and LSGPQAGLGEYLFER from ferritin and LGEHNIDVLEGNEQFINAAK from trypsinogen. The production and characterization of biopeptides is a new merging challenge of meat industry.

Investigating the calcium binding characteristics of black bean protein hydrolysate.

The black bean protein has been widely utilized to prepare hydrolysates with different bioactive properties. Herein, we hydrolyzed the black bean protein to prepare hydrolysate with calcium binding activity and characterized its behavior. Our results showed that ficin was superior in obtaining hydrolysate with calcium binding capacity in comparison with trypsin, alcalase and bromelain. In particular, the optimal capacity of ficin hydrolysate reached 77.54 ± 1.61 µg mg-1, where the optimal hydrolysis conditions of ficin were a temperature of 70 °C, a pH value of 6.2, an enzyme concentration of 1.61% and a time of 3 h. This might be due to high proportions of aspartic acid and glutamic acid (35.59%). Further spectral analysis evidenced the formation of hydrolysate-calcium complexes, demonstrating that the interaction between hydrolysate and calcium ions primarily occur on carboxyl oxygen atoms and amino nitrogen atoms. These findings provide a possible utilization of black bean hydrolysate to serve as a calcium supplement nutraceutical to enhance the absorption and bioavailability.

Unsaturated fatty acids enhance the fibrinolytic activity of subtilisin NAT (nattokinase).

Subtilisin NAT (STN), alternatively designated nattokinase, is a serine protease with potent fibrinolytic activity. In this study, we screened several foods to enhance the fibrinolytic potential of STN and identified unsaturated fatty acid-rich ones as candidates. We isolated linoleic acid as a major active compound from one of the most active foods, red pepper. Linoleic acid promoted the STN-mediated fibrin/fibrinogen degradation at >20 µg/ml. STN cleaved three of the fibrinogen polypeptide chains, among which linoleic acid accelerated Bß-chain and γ-chain degradations, but slightly suppressed the degradation of α-chain fragments. Linoleic acid failed to affect small synthetic peptide degradation, suggesting a conformational modulation of fibrin/fibrinogen for the linoleic acid promotion of STN activity. Of the various fatty acids tested, unsaturated ones were active but saturated ones were rather inhibitory to STN-mediated fibrinolysis. Thus, our data shed new light on the dietary promotion of STN activity. PRACTICAL APPLICATIONS: Subtilisin NAT (STN) is a serine protease abundantly contained in natto, a soybean food fermented with Bacillus subtilis var. natto. The use of STN as functional foods to improve blood circulation is getting attention because STN actively degrades fibrin. Our results demonstrate that widely occurring unsaturated fatty acids such as linoleic, eicosapentaenoic, and docosahexaenoic acids enhance the fibrinolytic activity of STN. Thus, the intake of natto or STN supplements in combination with unsaturated fatty acid-containing oil can be a novel way to gain cardiovascular benefits.

Clinical Value of Debriding Enzymes as an Adjunct to Standard Early Surgical Excision in Human Burns: A Systematic Review.

Burns are a significant public health burden worldwide. In addition to those who die, millions remain with life-threatening deformities and disabilities resulting in stigma and rejection. Surgical excision is currently the standard of care for removing necrotic tissues in burn wounds to prepare the wound bed for grafting or enhancing the healing process. However, there is a growing interest on enzymatic debridement as an adjunct therapy in burn wounds. The aim of this study was to investigate clinical trials using debriding agents for burn wound in humans in a systematic review. This was a systematic review of electronic databases including CINAHL, PubMed, Ovid Medline, Web of Science, Google Scholar, and Embase from January 1969 to February 2019. The study protocol was registered in PROSPERO registry. The following keywords were searched: "burn wounds", "enzymatic debridement", "papain", "papain-urea", "pine apple", "Bromelain", "collagenases", "Nexobrid", "Debrase", "Debridase", "Actinidia deliciosa", "Sutilains", "Debrace", "piruvat acid". Those studies fulfilling the inclusion and exclusion criteria with low score of bias based on Cochrane Bias Tool were reviewed. Sixteen investigations fulfilled our inclusion criteria to be reviewed. Six, seven, and three clinical trials on humans were found regarding collagenase, bromelain, and miscellaneous agents. Collagenase has been reported to be effective in burns below 25% of TBSA, especially in outpatients' clinics. However, Nexobrid has been shown to be effective in deep burns and decreases the percentage of graft without significant adverse effects. There was not enough evidence supporting the clinical values of Papain, Sutilains, Urea, etc. Surgical excision still remains the standard of care for burn wounds debridement. However, enzymatic debridement, especially Bromelain might help to reduce sessions for surgical debridement or area under graft as an adjunct treatment. Despite the fact, more studies with larger sample sizes and with less conflicts of interest are needed to clearly elucidate the exact role of Bromelain.

New Insights into the Antimicrobial Properties of Hydrolysates and Peptide Fractions Derived from Chia Seed (Salvia hispanica L.).

Bioactive peptides derived from chia (Salvia hispanica) seed with antioxidant, antihypertensive, and anti-inflammatory activities have been well documented; however, few studies describe the antimicrobial properties of these peptides, which is of great interest not only in the prevention of food-borne diseases but also food spoilage. The aim of this study was to generate chia seed peptides using microwave-assisted hydrolysis with sequential (alcalase + flavourzyme) enzymes (AF-MW), fractionate them into 3-10 and < 3 kDa fractions, and evaluate their potential antimicrobial activity towards Escherichia coli, Salmonella enterica, and Listeria monocytogenes. Overall, the peptide fraction < 3 kDa showed higher antimicrobial activity than both chia seed hydrolysate and peptide fraction 3-10 kDa. Furthermore, the < 3 kDa fraction showed remarkable increase in membrane permeability of E. coli (71.49% crystal violet uptake) and L. monocytogenes (80.10% crystal violet uptake). These peptides caused a significant extension in the lag phase, decreases in the maximum growth, and growth rate in the bacteria and promoted multiple indentations (transmembrane tunnels), membrane wrinkling, and pronounced deformations in the integrity of the bacterial cell membranes. Finally, a select group of peptides in the AF-MW < 3 kDa fraction contained 16 sequences with cationic and hydrophobic character, with seven of them sharing the exact same sequence (GDVIAIR) and eight of them having the amino acid K as either N- or C-terminal or both. In conclusion, our results indicate that bioactive peptides obtained from chia seed proteins by microwave and enzymatic hydrolysis could be employed as antimicrobial agents in foods and therapeutic applications.