Anti-aging activity of Syn-Ake peptide by in silico approaches and in vitro tests

The increase in the aging population worldwide has led scientists to turn to research to prevent the aging process. In this context, synthetic peptides emerge as candidate molecules for developing new anti-aging products. This study aims to investigate the possible interactions of Syn-Ake, a synthetic peptide, with matrix metalloproteinases (MMPs) and Sirtuin 1 (SIRT1), which are the targets of anti-aging activities with in silico approaches, and to determine the antioxidant activity, and safety profile of the peptide by in vitro methods such as cytotoxicity (MTT) and genotoxicity (Ames) tests. The molecular docking study showed that the docking score energy of MMP receptors was in the order of MMP-13 < MMP-8 < MMP-1. Syn-Ake peptide provided the lowest and the most stable binding to the SIRT1 receptor at -9.32 kcal/mol. Binding interaction and protein-ligand stability of Syn-Ake with MMPs and SIRT1 in a dynamic system were predicted by 50 ns molecular dynamic (MD) simulation studies. The MD results showed that the Syn-Ake peptide remained stable in the active site of MMP-13 and SIRT1 receptors during 50 ns simulations. In addition, the antioxidant activity of Syn-Ake was investigated using diphenyl-2-picril-hydrazine (DPPH) method since it is crucial to remove free radicals that are effective in skin aging. The results revealed the concentration-dependent increased DPPH radical scavenging activity of the peptide. Finally, the safety of the Syn-Ake was investigated, and the safe dose of the peptide was determined. In conclusion, in silico and in vitro analyses show that the Syn-Ake peptide may hold promise in anti-aging formulations with its high efficacy and safety profile.Communicated by Ramaswamy H. Sarma.

Evaluation of Antimicrobial Activities against Various E. coli Strains of a Novel Hybrid Peptide-LENART01

Finding the ideal antimicrobial drug with improved efficacy and a safety profile that eliminates antibiotic resistance caused by pathogens remains a difficult task. Indeed, there is an urgent need for innovation in the design and development of a microbial inhibitor. Given that many promising antimicrobial peptides with excellent broad-spectrum antibacterial properties are secreted by some frog species (e.g., bombesins, opioids, temporins, etc.), our goal was to identify the antimicrobial properties of amphibian-derived dermorphin and ranatensin peptides, which were combined to produce a hybrid compound. This new chimera (named LENART01) was tested for its antimicrobial activity against E. coli strains K12 and R1-R4, which are characterized by differences in lipopolysaccharide (LPS) core oligosaccharide structure. The results showed that LENART01 had superior activity against the R2 and R4 strains compared with the effects of the clinically available antibiotics ciprofloxacin or bleomycin (MIC values). Importantly, the inhibitory effect was not concentration dependent; however, LENART01 showed a time- and dose-dependent hemolytic effect in hemolytic assays.

Nigella damascena L. essential oil and its main constituents, damascenine and β-elemene modulate inflammatory response of human neutrophils ex vivo

Nigella damascena L belongs to Ranunculaceae family and is mentioned in Eastern traditional medicine for the treatment of high temperatures, regulation of menstruation or catarrhal affections. The anti-inflammatory activity of compounds present in the essential oil obtained from seeds of this plant can be found in literature, however no studies on immunomodulatory activity are provided. Hence, in this work anti-inflammatory activity of N. damascena seed essential oil as well as damascenine and main compound β-elemene was evaluated on ex-vivo lipopolysaccharide (LPS)-stimulated human neutrophils. For isolation of damascenine fast and efficient protocol was elaborated using high performance countercurrent chromatography technique for the first time. Also detailed spectroscopic characteristic of damascenine was provided for the first time. Damascenine was separated from the essential oil in a mixture of petroleum ether/acetonitrile/acetone (2:1.5:0.5 v/v/v) in reversed phase mode in 12 min with 99.47% purity. Essential oil, damascenine and β-elemene presented immunomodulatory activity evaluated in LPS-stimulated neutrophils ex vivo. All studied samples significantly inhibited release of interleukin 1 beta (IL-1β) and interleukin 8 (IL-8). What is more, damascenine and β-elemene decreased matrix metallopeptidase 9 (MMP-9) production similar to dexamethasone. The release of tumor necrosis factor (TNF-α) was also inhibited in all range of concentrations, however the activity was weaker then activity of dexametasone. The previously reported anti-inflammatory activity of damascenine and β-elemene investigated in murine models was confirmed in our study on human neuthrophils suggesting their possible strong inhibitory effect on inflammatory response progression.

Exploring the biological consequences of conformational changes in aspartame models containing constrained analogues of phenylalanine

The dipeptide aspartame (Asp-Phe-OMe) is a sweetener widely used in replacement of sucrose by food industry. 2',6'-Dimethyltyrosine (DMT) and 2',6'-dimethylphenylalanine (DMP) are two synthetic phenylalanine-constrained analogues, with a limited freedom in χ-space due to the presence of methyl groups in position 2',6' of the aromatic ring. These residues have shown to increase the activity of opioid peptides, such as endomorphins improving the binding to the opioid receptors. In this work, DMT and DMP have been synthesized following a diketopiperazine-mediated route and the corresponding aspartame derivatives (Asp-DMT-OMe and Asp-DMP-OMe) have been evaluated in vivo and in silico for their activity as synthetic sweeteners.

Design, synthesis and characterization of fMLF-mimicking AApeptides

The tripeptide N-formyl-Met-Leu-Phe (fMLF) is a potent neutrophil chemoattractant and the reference agonist for the G protein-coupled N-formylpeptide receptor (FPR). As it plays a very important role in host defense and inflammation, there has been considerable interest in the development of fMLF analogues in the hope of identifying potential therapeutic agents. Herein we report the design, synthesis, and evaluation of AApeptides that mimic the structure and function of fMLF. The lead AApeptides induced calcium mobilization and mitogen-activated protein kinase (MAPK) signal transduction pathways in FPR-transfected rat basophilic leukemic (RBL) cells. More intriguingly, at high concentrations, certain AApeptides were more effective than fMLF in the induction of calcium mobilization. Their agonistic activity is further supported by their ability to stimulate chemotaxis and the production of superoxide in HL-60 cells. Similarly to fMLF, these AApeptides are much more selective towards FPR1 than FPR2. These results suggest that the fMLF-mimicking AApeptides might emerge as a new class of therapeutic agents that target FPRs.