International Journal of Peptide Research and Therapeutics最新文献

Peptides, as therapeutic agents, can mimic the actions of molecules involved in inflammatory disorders. Antimicrobial peptides (AMPs), generated by the innate immune system in all organisms, exhibit a broad spectrum of biological functionalities, including immunomodulation. The purpose of this study was to evaluate the effect of two modified peptide derivatives based on rabbit and human cathelicidin (nrCap18 and nhCap18) on the level of pro-inflammatory and anti-inflammatory cytokines in PBMCs of rheumatoid arthritis patients and healthy individuals in vitro. At first, peripheral blood samples were taken from seven rheumatoid arthritis patients and seven healthy individuals, and their PBMCs were isolated and cultured. Next, the toxicity of peptides was evaluated on PBMCs of these individuals, and the potential for hemolysis of these peptides on human blood erythrocytes was also calculated. After PBMCs were treated by peptide, cytokine level changes were investigated in the supernatants. These peptides showed low toxicity on PBMCs and human red blood cells. Also, these peptides could modulate and regulate cytokines in both patient/healthy groups. It is hoped that the effects of these peptides on cytokines modulation and regulation can open a new window for introducing an anti-inflammatory peptide. However, animal studies and clinical trials are needed to prove this claim.

The delivery of peptides and proteins usually faces formulation development challenges attributed to the difficulties encountered in their stabilization. Nanoparticles offer an alternative to improve the physicochemical stability of such biomacromolecules, while increasing their bioavailability by overcoming biological absorption barriers. With this review, we aim to discuss the stability problems of proteins and peptides that have driven the scientific community to find in nanotechnology a valid alternative for oral administration of biomolecules. In addition, we describe the most commonly used nanoparticles for this purpose (e.g., polymers such as polylactic acid, poly(lactic-co-glycolic acid), polycaprolactone, modified chitosan, and lipids such as oil-in-water nanoemulsions, self-emulsified drug delivery systems, solid lipid nanoparticles, nanostructured lipid carriers, liposomes, as well as hybrid systems like micelles), and we show some of the most important recent applications of these nanoparticles for the delivery of proteins and peptides, including for the treatment of diabetes, viruses (such as HIV), cancer, as well as in the development of vaccines.

The peptide melittin is a promising possibility for cancer treatment. The present research evaluated the anticancer impact in vitro on breast cell lines using melittin, melittin-loaded pectin, and blank pectin. The “thin-layer hydration approach” was employed for generating the pectines; several melittin pectinal formulations were developed and studied in shape, size, polydispersity index, entrapment effectiveness, release kinetics, and stability. Breast cancer cells were tested using the hemolytic ability method, flow cytometry, the MTT test, the soft agar colony method, and wound healing analysis. The gene’s transcription was determined using real-time PCR (P < 0.05). Due to improved targeting, the effectiveness of encapsulation (83.57 ± 1.06), PDI (0.298 ± 0.65), and release percentage, as well as a significant anticancer impact on cell lines, this research demonstrated that melittin-loaded pectin is an adequate replacement in the treatment of breast cancer. The melittin-loaded pectin has a more significant impact on gene transcription in the examined cells than in other samples; it up-regulates the transcription of the Bax, P57, caspase3, and caspase9 genes while down-regulating the transcription of the MMP2, MMP2, and MMP9 genes (P < 0.05). In addition, compared to the melittin samples, they increased the apoptosis rate (by more than 40%) and hindered the invasion and migration of both cell lines. Our research has conclusively shown that melittin plasmid-loaded pectin has more anticancer properties than free melittin. This study has shown that pectins are appropriate vesicle transporters for melittin in contrast to the free form.

Endotoxin, also identified as lipopolysaccharide (LPS), is considered the pathogenic factor of septic shock triggered by Gram-negative bacteria and generates inflammatory responses. Synthetic peptides have attracted increasing attention from researchers for the blocking of LPS and treatment of sepsis. The aim of the study was to design a novel synthetic anti-endotoxin peptide and evaluate its effect in vitro. To design a new peptide, anti-endotoxin peptides were extracted from the APD3 site. The physicochemical features, secondary structure content, and tertiary structure type of each residue were determined by ProtParam, GOR IV, pep-fold, and I-TASSER. Hemolytic activity and cytotoxicity of the peptide on RAW264.7 cells were assessed by human RBC hemolysis test and MTT assay, respectively. Real-time PCR and western blot were used to evaluate the gene expression of IL-1β, TNF-α, IL-6, IL-10, iNOS, and TLR4, as well as the protein expression of NF-KB(P65), correspondingly. The designed peptide has 13 amino acid residues (GRRWWRFKKWWKF). The second structure of the peptide had 46.15% random coil and 53.85% extended strand. The results of the prediction of the tertiary structure demonstrated the peptide forms an alpha helix structure. It possesses low hemolytic activity and low cytotoxicity against RAW264.7 cells. This peptide remarkably restored LPS-induced TLR4 overexpression, and reduced gene expression of IL-1β, IL-6, iNOS, and TNF-α, whereas increased IL-10. This peptide significantly reduced the protein expression of NF-KB (P65). These findings imply that this peptide with low toxicity, hemolytic activity, and LPS-neutralizing activity merits more research as a possible anti-LPS agent for managing septic shock.

Eupolyphaga sinensis Walker (ESW), an animal drug in traditional Chinese medicine, has been used clinically for thousands of years for cardiovascular disease and osteoarthritis. Many studies of ESW have reported that it had anti-inflammatory and anti-tumor activities due to the small-molecule ingredients. However, large-molecule compounds of ESW representing significant pharmacological effects such as anti-thrombotic, anti-cancer, and anti-inflammatory have not been revealed yet. Here, a novel anticoagulant peptide (P9) containing 9 amino acids was isolated from the hydrolysate of aqueous extracts of ESW. Further, P9 synthesized by solid-phase synthesis showed 70% inhibition of thrombin, prolonging thrombin time to 17 s and activated partial thromboplastin time to 33 s. Molecular docking and spectroscopy demonstrated that P9 could inhibit thrombin activity by binding to the active site of thrombin and altering the secondary structure of thrombin. In an in vivo study, P9 enhanced the intensity of Phenylhydrazine-induced cardiac staining in thrombosed zebrafish with antithrombotic activity. The results suggest that peptides originating from ESW hydrolysates could exert an anticoagulant effect, which is likely to be a potential source of bioactive peptides with anticoagulant activity.

Diabetes mellitus (DM) is a chronic endocrine disorder with lifelong implications. The prevalence of this condition is steadily increasing, emphasizing the need for effective management to maintain healthy blood sugar levels and mitigate associated complications. While various antidiabetic medications are available, individuals with type 1 diabetes rely on lifelong insulin therapy, and those with type 2 diabetes may also require it if other oral treatments prove ineffective. This study focuses on peptide-based therapies approved for diabetes management, including insulin, incretin mimetics (GLP-1, GLP-1 analogues, and GIP analogues), and amylin analogues. The advent of peptide-based therapeutics represents significant progress in diabetes management. Peptides consist of short sequences of amino acids and offer immense potential for treating the complicated pathophysiology of diabetes. They exhibit higher potency and specificity, although their short half-life in the body, cost, and instability are notable drawbacks. Modification of the peptide chain structure and various formulation strategies to prolong their plasma circulation time and reduce the frequency of dosing aim to minimize drawbacks associated with the peptide molecules. Continuous advancements in drug delivery strategies have also resulted in the greater therapeutic efficacy of peptides, better disease management, and improved quality of life for patients.

In this comprehensive investigation, we conducted a rigorous analysis of antimicrobial peptides (AMPs) within two venomous lionfish species, Pterois antennata and Pterois radiata. Our approach combined transcriptomics and bioinformatics to elucidate a diverse repertoire of AMPs from venomous spines of these two fish species, encompassing known peptides like LEAP-2, NK-lysin, Perlwapin, Antileukoproteinase, pteroicidin-alpha, Dicentracin, defensin beta-like, hepcidin, and a hitherto undiscovered peptide termed ‘pteroicidin-delta; piscidin-like’. The impressive complexity of these fish’s immune systems is highlighted by their diverse array of AMPs. Our study adds to our knowledge of AMPs in venomous lionfish and emphasizes the significance of taking into account species-specific adaptations when examining host defense mechanisms. The recently discovered variations in peptides unveil intricate interactions within the lionfish immune responses. Future research should concentrate on elucidating the physiological significance of these AMPs in lionfish, shedding light on their roles in evolutionary biology, conservation, and medicine. The identification of the novel peptide “pteroicidin-delta; piscidin-like” is particularly noteworthy, holding promise for future biological studies. Its antimicrobial capabilities and potential medical applications could have significant implications for human health. This study underscores the importance of further research into these intriguing AMPs and their potential benefits across various scientific domains.

Abstract

In this study, an antimicrobial protein (AMP) from the epidermis of catfish (Clarias batrachus) was purified and characterized for its molecular and antimicrobial properties. The crude epidermal extract was subjected to precipitation of proteins using 70% ammonium sulphate saturation followed by dialysis and protein separation by reverse phase ultra fast liquid chromotography (UFLC) using the C₁₈ column. The active peptides obtained from fractions 1, 2, and 3 were screened for antimicrobial activity against different bacterial pathogens with a minimum 5 mg/ml inhibitory concentration. An active fraction with a retention time (RT) of 27.069 from the UFLC chromatogram exhibited significant antimicrobial activity against broad-spectrum bacterial and fungal organisms, including multidrug-resistant clinical isolates. The RT 27.069, identified as cationic AMP of fraction-3, has a molecular weight of 25 kDa as determined by MALDI-TOF mass spectrometry. Further studies by Mascot search and BLAST analysis using the partial sequence of AMP showed that the protein has high homologs to pleurocidin-like peptide (Plp) from a fish Pleuronectus americanus. Moreover, the identified AMP is a cationic peptide with a good stability index, having a score of 31.50 predicted by the ProtParam. Therefore, the identified antimicrobial peptide (Plp) indicates that this cost-effective natural substance obtained from fish could potentially be used as a treatment for several bacterial and fungal infections in humans.

Abstract

The aim of the paper was to develop chitosan-coated nanoliposomes for carrying bioactive peptides derived from hydrolyzed shrimp waste (SW) with chitosan coating (concentrations of 0, 0.5 and 1% W/ V). The study involved producing SW hydrolysates using protease enzymes from Bacillus salsus bacteria, followed by investigating the physicochemical, antioxidant, and antimicrobial properties of the peptide-loaded nanoliposomes. The dispersion index ranged from 0.17 to 0.65, and the particle size varied from 500 to 685 nm. Increasing the chitosan concentration to 1% significantly increased the particle size (P < 0.05). The Zeta potential of the nanoliposomes became positive as the chitosan concentration increased, starting from − 47.73 mV and reaching + 36.40 mV. The highest encapsulation efficiency (84.67%) was observed in nanoliposomes with 1% chitosan, while uncoated liposomes had the lowest encapsulation efficiency (44%). Scanning electron microscopy (SEM) revealed that the nanoparticles exhibited homogeneous, spherical, and cluster-shaped structures with smooth surfaces. Chitosan coating enhanced the stability of the peptides in simulated stomach and intestinal environments, with higher stability observed at higher chitosan concentrations (P < 0.05). Chitosan-coated nanoliposomes exhibited higher antioxidant and antimicrobial activities compared to uncoated nanoliposomes. Increasing the chitosan concentration resulted in greater inhibition of free radicals (DPPH and ABTS free radical activities increased significantly in nanoliposomes with 1% chitosan compared to uncoated samples: 32.56–70.28% and 41.58–80.28% respectively) and enhanced antimicrobial properties (P < 0.05). In conclusion, coating hydrolyzed SW with nanoliposomes and chitosan improved the structural, physicochemical, antioxidant, and antimicrobial properties of the peptides, making them suitable for direct application in food products requiring antioxidant and antimicrobial effects.

The two main characteristics of asthma pathogenesis are severe inflammation and excessive oxidative stress production. Biosurfactant (BS), as surface-active metabolites synthesized by microorganisms, is mainly isolated from bacterial strains and was previously reported to have various therapeutic functions, such as providing antioxidant and anti-inflammatory benefits. Our study aimed to investigate the anti-inflammatory and anti-oxidative role of lipopeptide BS using an experimental asthma model in rats. Lipopeptide BS was isolated from Acinetobacter junii B6. In vivo, male rats were randomly assigned into four groups (7 rats in each group); normal control rats (CTL), non-treated asthmatic rats, asthmatic rats received BS, and asthmatic rats treated with budesonide (positive control). Administration of ovalbumin (OVA) to rats was used to induce an allergic asthma model. At the end of the induction period, the ELISA method was used to determine the inflammatory and OS markers in BALF and lung tissue. Moreover, total protein and IgE concentrations were determined in lung tissue, BALF, and serum, respectively. A histological study of lung tissue was performed using H&E staining. Treatment with Lipopeptide BS decreased inflammatory cell count in lung tissue and also reduced the level of cytokines and oxidant parameters (TNF-α, IL-1β, IL-6 and MDA, total protein, nitrite) in both BALF and lung tissue. Also, the IgE level in serum was reduced by Lipopeptide BS administration. In contrast, the level of IL-10, TAC level, SOD, and GPX activity was elevated in both BALF and lung tissue following Lipopeptide BS administration. The histological evaluation indicated that Lipopeptide BS considerably inhibited histopathological changes, airway and epithelial damage, emphysema, and goblet cell hyperplasia in the tissue.

The preventive effect of Lipopeptide BS is potentially promising in asthma treatment through reducing histological changes, inflammation, and oxidative stress.