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1.
Chembiochem ; 24(15): e202300103, 2023 08 01.
Artículo en Inglés | MEDLINE | ID: mdl-37021633

RESUMEN

The SARS-CoV-2 virus that causes COVID-19 is a global health issue. The spread of the virus has resulted in seven million deaths to date. The emergence of new viral strains highlights the importance of continuous surveillance of the SARS-CoV-2 virus by using timely and accurate diagnostic tools. Here, we used a stable cyclic peptide scaffolds to present antigenic sequences derived from the spike protein that are reactive to SARS-CoV-2 antibodies. Using peptide sequences from different domains of SARS-CoV-2 spike proteins, we grafted epitopes on the peptide scaffold sunflower trypsin inhibitor 1 (SFTI-1). These scaffold peptides were then used to develop an ELISA to detect SARS-CoV-2 antibodies in serum. We show that displaying epitopes on the scaffold improves reactivity overall. One of the scaffold peptides (S2_1146-1161_c) has reactivity equal to that of commercial assays, and shows diagnostic potential.


Asunto(s)
COVID-19 , Humanos , SARS-CoV-2 , Epítopos , Anticuerpos Antivirales , Péptidos , Péptidos Cíclicos
2.
J Nat Prod ; 86(3): 566-573, 2023 03 24.
Artículo en Inglés | MEDLINE | ID: mdl-36917740

RESUMEN

The subtilisin-like macrocyclase PatGmac is produced by the marine cyanobacterium Prochloron didemni. This enzyme is involved in the last step of the biosynthesis of patellamides, a cyanobactin type of ribosomally expressed and post-translationally modified cyclic peptides. PatGmac recognizes, cleaves, and cyclizes precursor peptides after a specific recognition motif comprised of a C-terminal tail with the sequence motif -AYDG. The result is the native macrocyclic patellamide, which has eight amino acid residues. Macrocyclase activity can be exploited by incorporating that motif in other short linear peptide precursors, which then are formed into head-to-tail cyclized peptides. Here, we explore the possibility of using PatGmac in the cyclization of peptides larger than the patellamides, namely, the PawS-derived peptide sunflower trypsin inhibitor-1 (SFTI-1) and the cyclotide kalata B1. These peptides fall under two distinct families of disulfide constrained macrocyclic plant peptides. They are both implicated as scaffolds for drug design due to their structures and unusual stability. We show that PatGmac can be used to efficiently cyclize the 14 amino acid residue long SFTI-1, but less so the 29 amino acid residue long kalata B1.


Asunto(s)
Ciclotidas , Ciclotidas/química , Ciclización , Péptidos Cíclicos/química , Aminoácidos/metabolismo , Tripsina/química , Tripsina/metabolismo
3.
J Nat Prod ; 86(1): 52-65, 2023 01 27.
Artículo en Inglés | MEDLINE | ID: mdl-36525646

RESUMEN

Cyclotides are an intriguing class of structurally stable circular miniproteins of plant origin with numerous potential pharmaceutical and agricultural applications. To investigate the occurrence of cyclotides in Sri Lankan flora, 50 medicinal plants were screened, leading to the identification of a suite of new cyclotides from Geophila repens of the family Rubiaceae. Cycloviolacin O2-like (cyO2-like) gere 1 and the known cyclotide kalata B7 (kB7) were among the cyclotides characterized at the peptide and/or transcript level together with several putative enzymes, likely involved in cyclotide biosynthesis. Five of the most abundant cyclotides were isolated, sequenced, structurally characterized, and screened in antimicrobial and cytotoxicity assays. All gere cyclotides showed cytotoxicity (IC50 of 2.0-10.2 µM), but only gere 1 inhibited standard microbial strains at a minimum inhibitory concentration of 4-16 µM. As shown by immunohistochemistry, large quantities of the cyclotides were localized in the epidermis of the leaves and petioles of G. repens. Taken together with the cytotoxicity and membrane permeabilizing activities, this implicates gere cyclotides as potential plant defense molecules. The presence of cyO2-like gere 1 in a plant in the Rubiaceae supports the notion that phylogenetically distant plants may have coevolved to express similar cytotoxic cyclotides for a specific functional role, most likely involving host defense.


Asunto(s)
Ciclotidas , Plantas Medicinales , Rubiaceae , Secuencia de Aminoácidos , Ciclotidas/química , Proteínas de Plantas/química , Rubiaceae/química , Sri Lanka
4.
Cell Mol Life Sci ; 79(8): 411, 2022 Jul 11.
Artículo en Inglés | MEDLINE | ID: mdl-35821354

RESUMEN

The increasing antibiotic resistance among uropathogenic bacteria warrants alternative therapeutic strategies. We demonstrate the potential of the synthetic peptide CD4-PP, designed by dimerization and backbone cyclization of the shortest antimicrobial region of human cathelicidin, LL-37. CD4-PP is active against clinical and type strains of common uropathogens Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa at concentrations substantially below cellular cytotoxic levels and induced membrane deformation and leakage in E. coli and P. aeruginosa. Furthermore, CD4-PP treatment prevented the formation of new biofilm and dissolved mature biofilm created by E. coli and P. aeruginosa and targeted curli amyloid in E. coli biofilms. In addition, CD4-PP also induced production of LL-37 by uroepithelial cells and increased the expression of tight junction proteins claudin-14 and occludin. During uroepithelial cell infection, CD4-PP significantly reduced uropathogen survival when treatment was given at the start of infection. Low micromolar of CD4-PP treatment initiated after 2 h was successful with all tested species, except P. aeruginosa where CD4-PP was unable to reduce survival, which could be attributed by early biofilm formation. Finally, we demonstrated that urinary catheter pieces coated with saline fluid supplemented with CD4-PP reduced the attachment of E. coli, giving it a potential clinical application.


Asunto(s)
Péptidos Antimicrobianos , Escherichia coli , Biopelículas , Humanos , Klebsiella pneumoniae , Pseudomonas aeruginosa
5.
Nanotechnology ; 32(6): 065101, 2021 Feb 05.
Artículo en Inglés | MEDLINE | ID: mdl-33119546

RESUMEN

The current study reports advanced, ecofriendly and biosynthesized silver NPs for diverse biomedical and environmental applications using Flammulina velutipes as biosource. In the study, a simple aqueous extract of F. velutipes was utilized to reduce the AgNO3 into stable elemental silver (Ag0) at a nanometric scale. The NPs had average size of 21.4 nm, spherical morphology, and were highly stable and pure. The characterized nanoparticles were exploited for a broad range of biomedical applications including bacteriocidal, fungicidal, leishmanicidal, in vitro antialzheimer's, antioxidant, anti-diabetic and biocompatibility studies. Our findings showed that F. velutipes mediated AgNPs exhibited high activity against MDR bacterial strains and spore forming fungal strains. All the tested urinary tract infection bacterial isolates, were resistant to non-coated antibiotics but by applying 1% of the synthesized AgNPs, the bactericidal potential of the tested antibiotics enhanced manifolds. The NPs also exhibited dose-dependent cytotoxic potential against Leishmania tropica with significant LC50 of 248 µg ml-1 for promastigote and 251 µg ml-1 for amastigote forms of the parasite. Furthermore, promising antialzheimer and antidiabetic activities were observed as significant inhibition of α-amylase, α-glucosidase, acetylcholinesterase (AChE) and butrylcholineterase (BChE) were noted. Moreover, remarkable biocompatible nature of the particles was found against human red blood cells. The biosynthesized AgNPs as photocatalyst, also resulted in 98.2% degradation of indigo carmine dye within 140 min. Owing to ecofriendly synthesis, biosafe nature and excellent physicochemical properties F. velutipes AgNPs can be exploited as novel candidates for multifaceted biomedical and environmental applications.


Asunto(s)
Antiinfecciosos/farmacología , Flammulina , Nanopartículas del Metal/química , Plata/química , Plata/farmacología , Antibacterianos/química , Antibacterianos/farmacología , Antiinfecciosos/química , Antifúngicos/química , Antifúngicos/farmacología , Antioxidantes/química , Antioxidantes/farmacología , Relación Dosis-Respuesta a Droga , Dispersión Dinámica de Luz , Flammulina/química , Flammulina/metabolismo , Humanos , Hipoglucemiantes/química , Hipoglucemiantes/farmacología , Leishmania tropica/efectos de los fármacos , Nanopartículas del Metal/administración & dosificación , Pruebas de Sensibilidad Microbiana , Microscopía Electrónica de Rastreo , Inhibidores de Proteínas Quinasas/química , Inhibidores de Proteínas Quinasas/farmacología , Plata/administración & dosificación , Espectrofotometría Ultravioleta , Espectroscopía Infrarroja por Transformada de Fourier , Termogravimetría
6.
Chembiochem ; 19(9): 931-939, 2018 05 04.
Artículo en Inglés | MEDLINE | ID: mdl-29430821

RESUMEN

The human host defence peptide LL-37 is a broad-spectrum antibiotic with immunomodulatory functions. Residues 18-29 in LL-37 have previously been identified as a minimal peptide (KR-12) that retains antibacterial activity with decreased cytotoxicity. In this study, analogues of KR-12 were generated by Ala and Lys scans to identify key elements for activity. These were tested against a panel of human pathogens and for membrane permeabilisation on liposomes. Replacements of hydrophobic and cationic residues with Ala were detrimental for antibiotic potency. Substitutions by Lys increased activity, as long as the increase in cationic density did not disrupt the amphiphilic disposition of the helical structure. Importantly, substitutions showed differential effects against different organisms. Replacement of Gln5 with Lys and Asp9 with Ala or Lys improved the broad-spectrum activity most, each resulting in up to an eightfold increase in potency against Staphylococcus aureus, Pseudomonas aeruginosa and Candida albicans. The improved analogues displayed no significant toxicity against human cells, and thus, KR-12 is a tuneable template for antibiotic development.


Asunto(s)
Antiinfecciosos/química , Antiinfecciosos/farmacología , Péptidos Catiónicos Antimicrobianos/química , Péptidos Catiónicos Antimicrobianos/farmacología , Catelicidinas/química , Catelicidinas/farmacología , Fragmentos de Péptidos/química , Fragmentos de Péptidos/farmacología , Alanina/química , Alanina/genética , Alanina/farmacología , Alanina/toxicidad , Secuencia de Aminoácidos , Sustitución de Aminoácidos , Antiinfecciosos/metabolismo , Antiinfecciosos/toxicidad , Péptidos Catiónicos Antimicrobianos/genética , Péptidos Catiónicos Antimicrobianos/toxicidad , Candida albicans/efectos de los fármacos , Catelicidinas/genética , Catelicidinas/toxicidad , Línea Celular , Supervivencia Celular/efectos de los fármacos , Humanos , Lisina/química , Lisina/genética , Lisina/farmacología , Lisina/toxicidad , Pruebas de Sensibilidad Microbiana , Modelos Moleculares , Fragmentos de Péptidos/genética , Fragmentos de Péptidos/toxicidad , Pseudomonas aeruginosa/efectos de los fármacos , Staphylococcus aureus/efectos de los fármacos
7.
Tuberk Toraks ; 66(1): 26-31, 2018 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-30020038

RESUMEN

INTRODUCTION: Multidrug resistant TB (MDR-TB), defined as resistance to at least rifampicin and isoniazid together, has been rapidly spreading in recent years. In new pulmonary tuberculosis patients, rapid spread of MDR-TB and XDR-TB challenging the effectiveness of national TB control programs especially in many low-income countries. This study was aimed to determine the resistance pattern of Mycobacterium tuberculosis among new cases, cured, failure, relapse, defaulted, treatment completed, treatment not evaluated and suspect to be resistant to first line antitubercular drugs of pulmonary tuberculosis (PTB). MATERIALS AND METHODS: The study was conducted during 2013-2016 in which 148 patients were enrolled infected with pulmonary TB. Three sputum samples were consecutively collected and transported for drug analysis to the Provincial Reference Laboratory (PRL) at Hayatabad Medical complex Peshawar (HMCP) TB laboratory, within three days of collection at +4°C in a cold box. Using the standard proportion method, drug susceptibility test was performed on 132 (89.2%) sputum samples for rifampicin (R), isoniazid (H), pyrazinamide (Z), ethambutol (E), and streptomycin (S). RESULT: Prevalence of resistance to one drug was 5 (3.4%). The highest proportion of mono-drug resistance was observed against E, 3 (2%), followed by H, 1 (0.7%), and R, 1 (0.7%). Pattern of resistant to two drugs was 14 (9.5%). The proportion of poly resistant was 3 (2%). 112 (93.33%) diagnose patients were MDR-TB. CONCLUSIONS: To formulate an effective regimen, it is important to know drug resistant pattern because drug resistant pattern varies from different period of time also from one place to another.


Asunto(s)
Antituberculosos/uso terapéutico , Tuberculosis Resistente a Múltiples Medicamentos/tratamiento farmacológico , Tuberculosis Pulmonar/tratamiento farmacológico , Adulto , Etambutol/uso terapéutico , Femenino , Humanos , Isoniazida/uso terapéutico , Masculino , Mycobacterium tuberculosis/efectos de los fármacos , Pakistán , Prevalencia , Rifampin/uso terapéutico , Tuberculosis Resistente a Múltiples Medicamentos/epidemiología , Tuberculosis Pulmonar/epidemiología
8.
Biopolymers ; 108(3)2017 May.
Artículo en Inglés | MEDLINE | ID: mdl-28009046

RESUMEN

Cyclotides are considered promising scaffolds for drug development owing to their inherent host defence activities and highly stable structure, defined by the cyclic cystine knot. These proteins are expressed as complex mixtures in plants. Although several methods have been developed for their isolation and analysis, purification of cyclotides is still a lengthy process. Here, we describe the use of affinity chromatography for the purification of cyclotides using polyclonal IgG antibodies raised in rabbits against cycloviolacin O2 and immobilized on NHS-activated Sepharose columns. Cycloviolacin O2 was used as a model substance to evaluate the chromatographic principle, first as a pure compound and then in combination with other cyclotides, that is, bracelet cyclotide cycloviolacin O19 and Möbius cyclotide kalata B1, and in a plant extract. We demonstrate that single-step purification of cyclotides by affinity chromatography is possible but cross reactivity may occur between homologue cyclotides of the bracelet subfamily.


Asunto(s)
Anticuerpos/química , Cromatografía de Afinidad/métodos , Ciclotidas/química , Ciclotidas/aislamiento & purificación , Secuencia de Aminoácidos , Animales , Anticuerpos/inmunología , Ciclotidas/inmunología , Motivos Nodales de Cisteina/inmunología , Conejos
9.
J Ayub Med Coll Abbottabad ; 28(2): 259-261, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-28718547

RESUMEN

BACKROUND: Implants for open reduction and internal fixation of distal femoral fracture includes angle blade plate, rush nails, enders nail and interlocking nails. But all these devices are technically demanding and less effective in providing inter-fragmentary compression in osteoporotic bones. These problems can be solved with dynamic condylar screw (DCS).The objective of the study was to determine the frequency of different outcomes of distal femoral fracture treated with dynamic condylar screw. METHODS: This case series study was carried out in the Department of Trauma & Orthopaedics, Ayub Teaching Hospital Abbottabad from 1st October 2014 to August 2015, after approval of the ethical committee of the institution. Data of all patients with distal femoral fractures aged 20-70 years, recruited through emergency, OPD or consultant clinic collected on a pro forma. Standard treatment of trauma was given to the patients. Detailed history was taken including the past medical and surgical history. Detailed examination including air-way, breathing and circulation, general physical examination and abdomino-pelvic examination was done in each patient. Investigations including urinalysis, haemoglobin %, full blood count, X-ray (both AP and lateral view) of the involved femur (including hip and knee) was done. RESULTS: Mean age of the patients was 43.18±14.647 ranging from 20 to 70 years. Mean duration of hospital stay in days was 2.21±1.111 ranging from 1 to 6 days. Patients' follow-up assessment after 4 months of surgery for union of femoral fracture treated with dynamic condylar screw was found in 96 (94.1%), wound infection was found in 7 (6.9%), knee stiffness was found in 21 (20.6%) and limb shortening was found in 7 (6.9%). CONCLUSIONS: Dynamic condylar screw is an easy, scientifically less difficult and satisfying method of treatment for fra.ctures of femur.


Asunto(s)
Tornillos Óseos , Fracturas del Fémur/epidemiología , Fracturas del Fémur/cirugía , Fijación Interna de Fracturas , Adulto , Anciano , Estudios de Cohortes , Fijación Interna de Fracturas/efectos adversos , Fijación Interna de Fracturas/instrumentación , Fijación Interna de Fracturas/métodos , Humanos , Tiempo de Internación/estadística & datos numéricos , Persona de Mediana Edad , Complicaciones Posoperatorias , Resultado del Tratamiento , Adulto Joven
10.
J Ayub Med Coll Abbottabad ; 27(2): 476-8, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26411144

RESUMEN

Acinetobacter baumannii (A. baumannii), nosocomial infections, especially those due to multi-drug resistant (MDR) strains, are increasingly detected. This study reports the case of a 50-year-old man with blisters on the right knee for 8 months, first admitted through the outpatient department for incisional biopsy. Microbiological and histo-pathological examination confirmed the diagnosis of blisters extending deeply up to the knee joint caused by MDR- A. baumannii. A broad spectrum antibiotic therapy was administered and later readjusted according to the results of microbiological culture and biopsy report. Intensive hemodynamic support was required. An extensive surgical debridement was promptly performed and repeated until complete control of the infection with intravenous colistins. Blisters were excised; wounds were dressed daily with chlorhexidine dressings and polymyxine-impregnated dressing. Wounds were finally covered with split-thickness skin grafts. The infection was overcome 120 days after admission. The graft take was 40%. Postoperative rehabilitation was required because of the functional limitation of lower limb movements at the knee joint. Follow-up at 8 months showed no functional deficit and an acceptable aesthetic result. AB-MDR affecting soft tissues is a life-threatening disease, especially in patients with poor immunity and limited access to health facilities, whose clinical diagnosis may sometimes be challenging. Early recognition and treatment represent the most important factors influencing survival.


Asunto(s)
Infecciones por Acinetobacter/terapia , Acinetobacter baumannii/aislamiento & purificación , Antibacterianos/uso terapéutico , Vesícula/tratamiento farmacológico , Desbridamiento/métodos , Farmacorresistencia Bacteriana Múltiple/efectos de los fármacos , Rodilla/microbiología , Infecciones por Acinetobacter/microbiología , Acinetobacter baumannii/efectos de los fármacos , Vesícula/microbiología , Humanos , Rodilla/cirugía , Masculino , Persona de Mediana Edad
11.
PLoS One ; 19(1): e0296404, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38190387

RESUMEN

Sri Lanka is a biodiversity hotspot and one of the richest geographical locations of marine sponges in the Indian ocean. However, the most extensive taxonomical study on Sri Lankan sponge biodiversity dates back ~100 years and only a limited number of studies have been conducted on sponge natural products. In the current study, 35 marine sponge specimens (collected from 16 sponge habitats around Sri Lanka) were identified, microfractionated and evaluated for antibacterial and anticancer assays. In total, 30 species were characterized, of which 19 species gave extracts with antibacterial and/or cytotoxic activities. Microfractionated organic extract of Aciculites orientalis gave the most potent antibacterial activity against Staphylococcus aureus and strongest lymphoma cell toxicity was exhibited by the organic extract of Acanthella sp. Guided by the molecular ion peaks in the bioactive fractions, large-scale extraction of Stylissa massa led to the isolation of three bromopyrrole alkaloids, sceptrin, hymenin and manzacidin A/C. Of these, sceptrin exhibited broad spectrum antibacterial activity against both Escherichia coli and S. aureus (MIC of 62.5 µM against both species). Based on natural product literature, seven promising species were identified as understudied. Their further exploration may lead to the discovery of structurally novel compounds.


Asunto(s)
Alcaloides , Antineoplásicos , Productos Biológicos , Poríferos , Animales , Humanos , Sri Lanka , Staphylococcus aureus , Alcaloides/farmacología , Antibacterianos/farmacología , Antineoplásicos/farmacología , Productos Biológicos/farmacología , Escherichia coli
12.
Peptides ; 173: 171139, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38142817

RESUMEN

The recent COVID-19 pandemic shows the critical need for novel broad spectrum antiviral agents. Scorpion venoms are known to contain highly bioactive peptides, several of which have demonstrated strong antiviral activity against a range of viruses. We have generated the first annotated reference transcriptome for the Androctonus amoreuxi venom gland and used high performance liquid chromatography, transcriptome mining, circular dichroism and mass spectrometric analysis to purify and characterize twelve previously undescribed venom peptides. Selected peptides were tested for binding to the receptor-binding domain (RBD) of the SARS-CoV-2 spike protein and inhibition of the spike RBD - human angiotensin-converting enzyme 2 (hACE2) interaction using surface plasmon resonance-based assays. Seven peptides showed dose-dependent inhibitory effects, albeit with IC50 in the high micromolar range (117-1202 µM). The most active peptide was synthesized using solid phase peptide synthesis and tested for its antiviral activity against SARS-CoV-2 (Lineage B.1.1.7). On exposure to the synthetic peptide of a human lung cell line infected with replication-competent SARS-CoV-2, we observed an IC50 of 200 nM, which was nearly 600-fold lower than that observed in the RBD - hACE2 binding inhibition assay. Our results show that scorpion venom peptides can inhibit the SARS-CoV-2 replication although unlikely through inhibition of spike RBD - hACE2 interaction as the primary mode of action. Scorpion venom peptides represent excellent scaffolds for design of novel anti-SARS-CoV-2 constrained peptides. Future studies should fully explore their antiviral mode of action as well as the structural dynamics of inhibition of target virus-host interactions.


Asunto(s)
Animales Ponzoñosos , COVID-19 , Venenos de Escorpión , Glicoproteína de la Espiga del Coronavirus , Animales , Humanos , SARS-CoV-2/metabolismo , Escorpiones/química , Transcriptoma , Proteómica , Pandemias , Péptidos/metabolismo , Antivirales/farmacología , Venenos de Escorpión/química , Unión Proteica
13.
Biomedicines ; 11(2)2023 Feb 09.
Artículo en Inglés | MEDLINE | ID: mdl-36831040

RESUMEN

Is it possible to enhance structural stability and biological activity of KR-12, a truncated antimicrobial peptide derived from the human host defense peptide LL-37? Based on the mapping of essential residues in KR-12, we have designed backbone-cyclized dimers, cross-linked via a disulfide bond to improve peptide stability, while at the same time improving on-target activity. Circular dichroism showed that each of the dimers adopts a primarily alpha-helical conformation (55% helical content) when bound to lyso-phosphatidylglycerol micelles, indicating that the helical propensity of the parent peptide is maintained in the new cross-linked cyclic form. Compared to KR-12, one of the cross-linked dimers showed 16-fold more potent antimicrobial activity against human pathogens Pseudomonas aeruginosa, Staphylococcus aureus, and Candida albicans and 8-fold increased activity against Escherichia coli. Furthermore, these peptides retained antimicrobial activity at physiologically relevant conditions, including in the presence of salts and in human serum, and with selective Gram-negative antibacterial activity in rich growth media. In addition to giving further insight into the structure-activity relationship of KR-12, the current work demonstrates that by combining peptide stabilization strategies (dimerization, backbone cyclization, and cross-linking via a disulfide bond), KR-12 can be engineered into a potent antimicrobial peptide drug lead with potential utility in a therapeutic context.

14.
ACS Infect Dis ; 9(5): 1056-1063, 2023 05 12.
Artículo en Inglés | MEDLINE | ID: mdl-37132993

RESUMEN

Dermal infections requiring treatment are usually treated with conventional antibiotics, but the rise of bacterial resistance to first-line antibiotics warrants alternative therapeutics. Here, we report that a backbone-cyclized antimicrobial peptide, CD4-PP, designed from the human host defense peptide LL-37, has strong direct antibacterial effects on antibiotic sensitive as well as resistant-type strains and clinical isolates of common skin pathogens in the low (<2) µM range. In addition, it influences innate immunity in keratinocytes, and treatment with CD4-PP is able to clear bacterial infections in infected keratinocytes. Additionally, CD4-PP treatment significantly reduces the wound area in a lawn of keratinocytes infected with MRSA. In conclusion, CD4-PP has the potential to serve as a future drug treating wounds infected with antibiotic-resistant bacteria.


Asunto(s)
Péptidos Antimicrobianos , Piel , Humanos , Antibacterianos/farmacología , Queratinocitos , Péptidos Catiónicos Antimicrobianos/farmacología
15.
ACS Appl Mater Interfaces ; 15(20): 24186-24196, 2023 May 24.
Artículo en Inglés | MEDLINE | ID: mdl-37167266

RESUMEN

This work combines the wound-healing-related properties of the host defense peptide KR-12 with wood-derived cellulose nanofibrils (CNFs) to obtain bioactive materials, foreseen as a promising solution to treat chronic wounds. Amine coupling through carbodiimide chemistry, thiol-ene click chemistry, and Cu(I)-catalyzed azide-alkyne cycloaddition were investigated as methods to covalently immobilize KR-12 derivatives onto CNFs. The effects of different coupling chemistries on the bioactivity of the KR12-CNF conjugates were evaluated by assessing their antibacterial activities against Escherichia coli and Staphylococcus aureus. Potential cytotoxic effects and the capacity of the materials to modulate the inflammatory response of lipopolysaccharide (LPS)-stimulated RAW 245.6 macrophages were also investigated. The results show that KR-12 endowed CNFs with antibacterial activity against E. coli and exhibited anti-inflammatory properties and those conjugated by thiol-ene chemistry were the most bioactive. This finding is attributed to a favorable peptide conformation and accessibility (as shown by molecular dynamics simulations), driven by the selective chemistry and length of the linker in the conjugate. The results represent an advancement in the development of CNF-based materials for chronic wound care. This study provides new insights into the effect of the conjugation chemistry on the bioactivity of immobilized host defense peptides, which we believe to be of great value for the use of host defense peptides as therapeutic agents.


Asunto(s)
Antibacterianos , Escherichia coli , Antibacterianos/química , Péptidos Catiónicos Antimicrobianos/química , Staphylococcus aureus , Fenómenos Químicos
16.
Diagnostics (Basel) ; 11(8)2021 Jul 28.
Artículo en Inglés | MEDLINE | ID: mdl-34441289

RESUMEN

The diagnosis of Hepatitis C virus (HCV) infection can be challenging due to its cost and a lack of access to centralized testing. There is an urgent need to develop simplified HCV testing algorithms. The aim of this study was to evaluate the performance characteristics of a Hepatitis C core antigen (HCVcAg) assay in a decentralized, resource-limited setting. This is a descriptive cross-sectional study from a highly endemic area of Karachi, Pakistan. Between October 2019 and July 2020, subjects aged 12 years and above who screened positive for HCV antibodies were simultaneously tested for HCV RNA (Xpert HCV Viral Load, GeneXpert® IV, Cepheid, France) and HCVcAg (ARCHITECT HCV Ag assay, Abbott® Diagnostics) to confirm active HCV infection. An Abbott ARCHITECT® i1000SR Immunoassay Analyser was installed at a local district hospital as a point-of-care (POC) facility for HCVcAg testing, while samples for HCV RNA were tested in a central lab. Two hundred individuals (mean age 46.4 ± 14.5 years, 71.5% females), who screened positive for HCV antibody, were included in the study. HCV RNA was detected in 128 (64.0%) while HCVcAg was reactive in 119 (59.5%) cases. Performance of the Immunoassay Analyser was excellent with a higher throughput and quicker readout value compared to the GeneXpert System. The sensitivity and specificity of HCVcAg (≥10 fmol/L) at HCV RNA thresholds of ≥12 was 99.1% (95% CI: 95-100%) and 87.6% (95%CI: 78.4-94%). A strong agreement was observed between the HCVcAg assay and HCV RNA. The ARCHITECT HCV Ag assay showed high sensitivity and specificity compared to HCV RNA in a decentralized, resource-limited setting. It can therefore be used as a confirmatory test in HCV elimination programs, particularly for low-income countries such as Pakistan.

17.
Front Pharmacol ; 12: 661803, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34093192

RESUMEN

Morchella conica (M. conica) Pers. is one of six wild edible mushrooms that are widely used by Asian and European countries for their nutritional value. The present study assessed the anti-diabetic potential of M. conica methanolic extract (100 mg/kg body weight) on streptozotocin (STZ)-induced diabetic mice. STZ was used in a single dose of 65 mg/kg to establish diabetic models. Body weights, water/food intake and fasting blood glucose levels were measured. Histopathological analysis of the pancreas and liver were performed to evaluate STZ-induced tissue injuries. In addition, in vitro assays such as α-amylase and protein tyrosine phosphatase 1B (PTP1B) inhibitory, antiglycation, antioxidant and cytotoxicity were performed. The in vitro study indicated potent PTP1B inhibitory potential of M. conica with an IC50 value of 26.5 µg/ml as compared to the positive control, oleanolic acid (IC50 36.2 µg/ml). In vivo investigation showed a gradual decrease in blood sugar level in M. conica-treated mice (132 mg/dl) at a concentration of 100 mg/kg as compared to diabetic mice (346 mg/dl). The extract positively improved liver and kidney damages as were shown by their serum glutamic pyruvic transaminase, serum glutamic oxaloacetate, alkaline phosphatase, serum creatinine and urea levels. Histopathological analysis revealed slight liver and pancreas improvement of mice treated with extract. Cytotoxicity assays displayed lower IC50 values. Based on the present results of the study, it may be inferred that M. conica are rich in bioactive compounds responsible for antidiabetic activity and this mushroom may be a potential source of antidiabetic drug. However, further studies are required in terms of isolation of bioactive compounds to validate the observed results.

18.
RSC Chem Biol ; 2(6): 1682-1691, 2021 Dec 02.
Artículo en Inglés | MEDLINE | ID: mdl-34977583

RESUMEN

Head-to-tail cyclic and disulfide-rich peptides are natural products with applications in drug design. Among these are the PawS-Derived Peptides (PDPs) produced in seeds of the daisy plant family. PDP-23 is a unique member of this class in that it is twice the typical size and adopts two ß-hairpins separated by a hinge region. The ß-hairpins, both stabilised by a single disulfide bond, fold together into a V-shaped tertiary structure creating a hydrophobic core. In water two PDP-23 molecules merge their hydrophobic cores to form a square prism quaternary structure. Here, we synthesised PDP-23 and its enantiomer comprising d-amino acids and achiral glycine, which allowed us to confirm these solution NMR structural data by racemic crystallography. Furthermore, we discovered the related PDP-24. NMR analysis showed that PDP-24 does not form a dimeric structure and it has poor water solubility, but in less polar solvents adopts near identical secondary and tertiary structure to PDP-23. The natural role of these peptides in plants remains enigmatic, as we did not observe any antimicrobial or insecticidal activity. However, the plasticity of these larger PDPs and their ability to change structure under different conditions make them appealing peptide drug scaffolds.

19.
Saudi J Biol Sci ; 28(8): 4329-4333, 2021 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-34354416

RESUMEN

The Bt-cotton RH-647 was developed by Cotton Research Institute CRI, Khanpur has been acknowledged for its possesses superior plant characteristics and potential to yield out under harsh agro-climatic conditions of cotton productive district of Rahimyar Khan in Bahawalpur Division and southern Punjab in 2016. RH- 647 for its novel plant structure and improved fiber quality heat and drought tolerant to withstand successfully sustain yield out in harsh, highly variable hot and dry climatic conditions of and harsh seasoned. RH-647 was developed through one-way hybridization of elite parental genotypes accompanied by pedigree selection method through gene pyramiding technique for incorporation of excellent combinations of fiber traits and CLCuV disease tolerance with higher yield potential right from F1 population. The superior plant combinations were selected in F2-F6 generations were entirely based on phenotypic plant traits and progeny yield potential in field, plant shape, number of bolls per plant, average boll weight (g) and fiber quality traits over standard varieties. The single plant progenies were selected 56 sister lines were tested for Bt-gene (Cry1 Ac) were evaluated for high yielding performance for this superior cross and finally RH-647 as superior breeding line was bulked in year 2010. The strain was evaluated in Randomized Complete Block Design in preliminary yield trials (PYT) and two years in Advance Yield Trials (AYT) trials and Zonal Varietal trials for two years. The superior line 647/10 was ensued for performance in variety attestation tests as RH-647. RH-647 performed best in two years varietal trials (NCVT and PCCT and DUS) conducted for two successive growing seasons (2014-2015 and 2015-2016). RH-647 yielded out significantly compared with standard varieties MNH-886, FH-142 and CIM 602. After completion of mandatory trials in year 2016, RH-647 was approved as new Bt. cotton variety "RH-647". RH-647 is early in maturity with high yield potential and best suited for wheat-cotton cropping pattern. It has fluffy opening and is easy to pick, strongly tolerant to CLCuV disease, high Ginning out turn GOT% (40.2%) with improved fiber traits; staple length (28.3 mm), fiber strength (4.2ug/inch) is duly capable to fulfill all industrial requisitions.

20.
ACS Omega ; 6(14): 9709-9722, 2021 Apr 13.
Artículo en Inglés | MEDLINE | ID: mdl-33869951

RESUMEN

In the present work, bioaugmented zinc oxide nanoparticles (ZnO-NPs) were prepared from aqueous fruit extracts of Myristica fragrans. The ZnO-NPs were characterized by different techniques such as X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, ultraviolet (UV) spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), dynamic light scattering (DLS), and thermogravimetric analysis (TGA). The crystallites exhibited a mean size of 41.23 nm measured via XRD and were highly pure, while SEM and TEM analyses of synthesized NPs confirmed their spherical or elliptical shape. The functional groups responsible for stabilizing and capping of ZnO-NPs were confirmed using FTIR analysis. The ζ-size and ζ-potential of synthesized ZnO-NPs were reported as 66 nm and -22.1 mV, respectively, via the DLS technique can be considered as moderate stable colloidal solution. Synthesized NPs were used to evaluate for their possible antibacterial, antidiabetic, antioxidant, antiparasitic, and larvicidal properties. The NPs were found to be highly active against bacterial strains both coated with antibiotics and alone. Klebsiella pneumoniae was found to be the most sensitive strain against NPs (27 ± 1.73) and against NPs coated with imipinem (26 ± 1.5). ZnO-NPs displayed outstanding inhibitory potential against enzymes protein kinase (12.23 ± 0.42), α-amylase (73.23 ± 0.42), and α-glucosidase (65.21 ± 0.49). Overall, the synthesized NPs have shown significant larvicidal activity (77.3 ± 1.8) against Aedes aegypti, the mosquitoes involved in the transmission of dengue fever. Similarly, tremendous leishmanicidal activity was also observed against both the promastigote (71.50 ± 0.70) and amastigote (61.41 ± 0.71) forms of the parasite. The biosynthesized NPs were found to be excellent antioxidant and biocompatible nanomaterials. Biosynthesized ZnO-NPs were also used as photocatalytic agents, resulting in 88% degradation of methylene blue dye in 140 min. Owing to their eco-friendly synthesis, nontoxicity, and biocompatible nature, ZnO-NPs synthesized from M. fragrans can be exploited as potential candidates for biomedical and environmental applications.

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