Search Results (11)

Recent studies support the concept of a bidirectional lung–brain axis. While neural, immune, and microbial pathways are increasingly recognized in lung-to-brain communication, the role of matrikines—bioactive peptides generated by extracellular matrix (ECM) proteolysis during remodeling—in this inter-organ communication remains underexplored. This review highlights matrikines originating from the lung, particularly the collagen-derived tripeptide Pro-Gly-Pro (PGP) and the elastin-derived hexapeptide Val-Gly-Val-Ala-Pro-Gly (VGVAPG), as potential mediators linking pulmonary pathology with neurological outcomes. The lung is rich in ECM proteins, and inflammatory conditions such as chronic obstructive pulmonary disease (COPD) and emphysema trigger proteolytic activity by matrix metalloproteinases (MMPs) and neutrophil elastase, releasing matrikines into circulation. Under conditions of blood–brain barrier (BBB) dysfunction, they may access the central nervous system (CNS), where they influence neurons, microglia, and astrocytes, modulating neuroinflammation, autophagy, and synaptic integrity. While PGP can exhibit context-dependent neuroprotective effects, its acetylated form and VGVAPG are associated with neurotoxicity, Tau hyperphosphorylation, and microglial activation. Additional matrikines, including Gly-His-Lys (GHK) and endorepellin, may further modulate CNS homeostasis. Collectively, these findings support lung-derived matrikines as circulating mediators of lung-to-brain signaling, providing a novel mechanistic framework linking chronic pulmonary inflammation to neuropathologies, such as stroke and neurodegenerative disorders, and highlighting potential targets for therapeutic intervention. Full article

Biomimetic peptides represent a growing class of active ingredients in modern cosmeceuticals, designed to mimic the function of the naturally occurring peptides involved in skin homeostasis, repair, and regeneration. Among them, acetyl hexapeptide-8 (AH-8), often referred to as a “botox-like” peptide, has received considerable attention for its potential to dynamically reduce wrinkles through the modulation of neuromuscular activity. AH-8 is widely used in topical formulations intended for anti-aging effects, scar treatment, and skin rejuvenation. This review provides a comprehensive overview of the structure and proposed mechanisms of action of AH-8, with particular focus on its efficacy and skin penetration properties. Due to its hydrophilic nature and relatively large molecular size, AH-8 faces limited permeability through the lipophilic stratum corneum, making effective dermal delivery challenging. Formulation strategies such as oil-in-water (O/W) and multiple water-in-oil-in-water (W/O/W) emulsions have been explored to enhance its delivery, but the ability of AH-8 to reach neuromuscular junctions remains uncertain. Preclinical and clinical studies indicate that AH-8 may reduce wrinkle depth, improve skin elasticity, and enhance hydration. However, the precise biological mechanisms underlying these effects—particularly the peptide’s ability to inhibit muscle contraction when applied topically—remain incompletely understood. In some studies, AH-8 has also shown beneficial effects in scar remodeling and sebum regulation. Despite promising cosmetic outcomes, AH-8’s low skin penetration limits its bioavailability and therapeutic potential. This review emphasizes the need for further research on formulation science and delivery systems, which are essential for optimizing the effectiveness of peptide-based cosmeceuticals and validating their use as non-invasive alternatives to injectable treatments. Full article

Objective: Dermo-cosmetics have significantly advanced, focusing on innovative and effective products such as cosmeceuticals—cosmetics infused with bioactive ingredients for skin benefits. Synthetic peptides are prominent among these bioactive molecules, noted for their enhanced effects in cellular processes related to skin physiology. Specifically, the glycoprotein E-cadherin plays a crucial role in cellular adhesion and has shown promise in wound healing studies, although its broader cellular functions remain underexplored. Despite their widespread use, many cosmetic peptides lack genetic validation of their effects. This study focuses on the synthetic, amphiphilic acetyl hexapeptide-1, aimed to possess wound healing and anti-aging properties, with a novel exploration of its molecular mechanisms, specifically its effect on the expression of the CDH-1 gene, which encodes E-cadherin—a key protein in cellular adhesion and wound healing. Methods: In this investigation, the acetyl hexapeptide-1 was synthesized in house, followed by cell culture assessment and molecular evaluation. Human hepatocytes HepG2 were exposed to the synthetic hexapeptide to assess cytotoxic effects and examine its impact on gene expression, specifically targeting the wound healing-associated gene CDH-1, as well as apoptosis-related genes BAX, Bcl-2, Caspase-9, and Cyclin D1. Results: No cytotoxic effects were observed in cell cultures. Gene expression analysis revealed a significant increase in E-cadherin expression, along with the NO modulation of apoptosis-related genes (BAX, Bcl-2, Caspase-9) and the cell cycle-related gene Cyclin D1. These findings suggest peptide’s role in enhancing cellular adhesion, without any cytotoxic effects. Conclusions: The findings of this study provide promising insights into the potential molecular properties of synthetic acetyl hexapeptide-1, implying its applicability in cosmeceuticals. These cosmetic peptides hold enormous potential and diverse applications not only within skincare. To fully understand their benefits and expand their scope, additional investigations are warranted to comprehensively explore their molecular mechanisms across a spectrum of applications. Full article

This study aimed to evaluate Zn/Ag-electrode-printed patches for the transdermal delivery of small molecules through iontophoresis. The Zn/Ag-electrode-printed patches interact with biological liquid electrolytes and generate suitable microcurrents for the iontophoretic delivery of small molecules across the skin. In fluorescein permeation studies, Zn/Ag-electrode-printed patches increased the transdermal depth of fluorescein into the dermis, while the permeation of fluorescein was limited when Zn/C-electrode-printed patches were tested. Further permeation experiments were conducted with 3D skin models, which showed a similar trend to the above, indicating that Zn/Ag-electrode-printed patches had a higher penetration rate compared to the blank. Studies using acetyl hexapeptide-8 as a peptide drug model and sodium ascorbyl phosphate (SAP) as a hydrophilic derivative of ascorbic acid showed that the iontophoretic patch with Zn/Ag electrodes promoted more penetration of drugs than unprinted patches. The permeation of SAP exhibited a two-phase profile with a relatively rapid permeation followed by a sustained, slower permeation. The permeation of acetyl hexapeptide-8 was slower due to its higher molecular weight, but the iontophoretic patch increased the permeation up to 1.5 times more than the unprinted patch. The microcurrent generated by the patch drives the transport of small molecule components through the skin, for the controlled and efficient delivery of therapeutic agents. The flexible design, efficient microcurrent generation, and stable electrodes make the Zn/Ag-electrode-printed patch a promising tool for transdermal drug delivery. Full article

New peptide-based hydrogels incorporating Gd(III) chelates with different hydration states, molecular structures and overall negative charges ([Gd(BOPTA)]²⁻), [Gd(DTPA)]²⁻, and ([Gd(AAZTA)]⁻) were prepared and characterized. N-terminal Fmoc- or acetyl-derivatized hexapeptides (K1, K2 and K3) containing five aliphatic amino acids (differently ordered Gly, Ala, Val, Leu and Ile) and a charged lysine at the amidated C-terminal were used for the formation of the hydrogels. Particular attention was paid to the investigation of the morphological and rheological properties of the nanoparticles, in addition to the assessment of the ability (relaxivity) of the confined complexes to accelerate the longitudinal relaxation rate of the water protons localized in the polymeric network. The relaxivity values at high magnetic fields (>0.5 T) of the paramagnetic hydrogels appear to be more than five times higher than those of isolated chelates in an aqueous solution, reaching a value of 25 mmol⁻¹ s⁻¹ for Fmoc-K2+[Gd(BOPTA)]²⁻ at 0.5 T and 310 K. Furthermore, an interesting trend of decrease of relaxivity with increasing the degree of rigidity of the hydrogel was observed. The type of interactions between the various complexes and the polymeric network also plays a key role in influencing the relaxivity values of the final materials. Nanogels were also obtained from the submicronization of the hydrogel containing [Gd(BOPTA)]²⁻ chelate. Circular dichroism, dynamic light scattering and relaxometric investigations on these nanoparticles revealed the formation of nanogels endowed with higher relaxivities (r₁ = 41 mM⁻¹ s⁻¹ at 0.5 T MHz and 310 K) than the corresponding hydrogels. Full article

Bioactive peptides are gaining more and more popularity in the research and development of cosmetic products with anti-aging effect. Acetyl hexapeptide-8 is a hydrophilic peptide incorporated in cosmetics to reduce the under-eye wrinkles and the forehead furrows. Hydrophilic interaction liquid chromatography (HILIC) is the separation technique of choice for analyzing peptides. In this work, a rapid HILIC method coupled to photodiode array detection operated at 214 nm was developed, validated and used to determine acetyl-hexapeptide-8 in cosmetics. Chromatography was performed on a Xbridge^® HILIC BEH analytical column using as mobile phase a 40 mM ammonium formate water solution (pH 6.5)-acetonitrile mixture 30:70, v/v at flow rate 0.25 mL min⁻¹. The assay was linear over the concentration range 20 to 30 μg mL⁻¹ for the cosmetic formulations and 0.004 to 0.007% (w/w) for the cosmetic cream. The limits of quantitation for acetyl hexapeptide-8 were 1.5 μg mL⁻¹ and 0.002% (w/w) for the assay of cosmetic formulations and cosmetic creams, respectively. The method was applied to the analysis of cosmetic formulations and anti-wrinkle cosmetic creams. Full article

Sensitive skin is characterized by symptoms of discomfort when exposed to environmental factors. Peptides are used in cosmetics for sensitive skin and stand out as active ingredients for their ability to interact with skin cells by multiple mechanisms, high potency at low dosage and the ability to penetrate the stratum corneum. This study aimed to analyze the composition of 88 facial cosmetics for sensitive skin from multinational brands regarding usage of peptides, reviewing their synthetic pathways and the scientific evidence that supports their efficacy. Peptides were found in 17% of the products analyzed, namely: acetyl dipeptide-1 cetyl ester, palmitoyl tripeptide-8, acetyl tetrapeptide-15, palmitoyl tripeptide-5, acetyl hexapeptide-49, palmitoyl tetrapeptide-7 and palmitoyl oligopeptide. Three out of seven peptides have a neurotransmitter-inhibiting mechanism of action, while another three are signal peptides. Only five peptides present evidence supporting their use in sensitive skin, with only one clinical study including volunteers having this condition. Noteworthy, the available data is mostly found in patents and supplier brochures, and not in randomized placebo-controlled studies. Peptides are useful active ingredients in cosmetics for sensitive skin. Knowing their efficacy and synthetic pathways provides meaningful insight for the development of new and more effective ingredients. Full article

The development of synthetic peptides for skin care dates to the 1980s. The cosmetic industry periodically launches new peptides, as they are promising and appealing active ingredients in the growing and innovative cosmetics market. In this study, trends in the use of peptides in anti-aging products were analyzed by comparing the composition of the products marketed in 2011 with products launched or reformulated in 2018. The scientific and marketing evidence for their application as active ingredients in anti-aging cosmetics was also compiled from products’ labels, suppliers’ technical data forms and online scientific databases. The use of peptides in anti-aging cosmetics increased by 7.2%, while the variety and the number of peptide combinations in products have increased by 88.5%. The most used peptides in antiaging cosmetic formulations are, in descending order, Palmitoyl Tetrapeptide-7, Palmitoyl Oligopeptide and Acetyl Hexapeptide-8. In 2011, the majority of peptides were obtained from synthesis, while in 2018, biotechnology processing was the dominant source. This study provides an overview of the market trends regarding the use of peptides in anti-aging products, providing meaningful data for scientists involved in the development of new peptides to identify opportunities for innovation in this area. Full article

Ultraviolet (UV) irradiation is a potent inducer for skin photoaging. This paper investigated the anti-photoaging effects of the acetylated and amidated hexapeptide (AAH), originally identified from Spirulina platensis, in (Ultraviolet B) UVB-irradiated Human immortalized keratinocytes (Hacats) and mice. The results demonstrated that AAH had much lower toxicity on Hacats than the positive matrixyl (81.52% vs. 5.32%). Moreover, AAH reduced MDA content by 49%; increased SOD, CAT, and GSH-Px activities by 103%, 49%, and 116%, respectively; decreased MMP-1 and MMP-3 expressions by 27% and 29%, respectively, compared to UVB-irradiated mice. Employing isobaric tags for relative and absolute quantitation (iTRAQ)-based proteomics, 60 differential proteins were identified, and major metabolic pathways were determined. Network analysis indicated that these differential proteins were mapped into an interaction network composed of two core sub-networks. Collectively, AAH is protective against UVB-induced skin photoaging and has potential application in skin care cosmetics. Full article

Peptides of synthesis are a very new strategy in cosmetic science and technology for at least two reasons: (1) they are small molecules, easily penetrable in the skin and (2) they are able to induce a very specific action, because all skin cells (keratinocytes, fibroblasts, nervous cells) have membrane receptors for peptides. This group of cosmeceutics includes the botox-like peptides, represented by acetyl hexapeptide 3 (Argireline) and pentapeptid-3 (Leuphasyl). The latter is less known and has been less studied. This substance inhibits the neuromuscular synapses in the mimic muscles, acting as enkephalins. It links the enkephalin receptor to nervous cells, thereby modulating the release of acetylcholine in synaptic space. This cellular activity will be translated in vivo in a relaxation of the muscle and a reduction of expression wrinkles. The aim of our study is to evaluate the optimal concentration of Leuphasyl for skin application at the mimic muscle level, the efficiency and the safety of this peptide. We formulated three emulsions of different concentrations (0.5%, 1%, 2%) which were applied to the skin, at the level of mimic muscles (1) at the eyebrows zone (above the corrugator supercilii muscle) and (2) at the periorbital zone (above the orbicularis oculi muscle). We evaluated the regression of the wrinkles between the eyebrows using an imagistic method: pro-derm Analyser. The study is of interest to discussions concerning how to apply these kinds of cosmetic products at the mimic muscle skin level and not at the level of the wrinkles. Full article