Search Results (1,377)

We recently published that phycocyanin, a phycobiliprotein which accounts for up to 20% of Arthrospira platensis dry weight, has a powerful anti-aging effect, greatly extending the chronological life span (CLS) of yeast cells grown in synthetic-defined medium, both under caloric restriction (CR) conditions (0.2% glucose) or under non-CR conditions (2% glucose). In this study, to explore the molecular mechanisms underlying the effects of phycocyanin, we investigated its impact on key signaling pathways involved in aging. Specifically, we performed CLS experiments using ras2Δ and snf1Δ yeast mutants. The Snf1 pathway is known to promote longevity (anti-aging), whereas the Ras2/PKA pathway accelerates aging (pro-aging). We show that, while in the snf1Δ mutant the anti-aging effect of phycocyanin was still evident, in the ras2Δ mutant, phycocyanin did not appear to exert any anti-aging activity, leading us to hypothesize that the Ras2/PKA pathway may be essential to mediate the anti-aging effect of phycocyanin. To evaluate the activity of phycocyanin under different nutritional conditions, we performed the CLS experiment in a YPDA-rich medium. We show that in this medium, phycocyanin accelerated the chronological aging process of yeast cells, greatly decreasing the CLS, both when glucose was present at low (0.2%) or at high (2%) concentration. Our data suggest that Saccharomyces cerevisiae could serve as a model not only to investigate the anti-aging properties and targets of phycocyanin, but also its potential side effects, which are possibly present in higher eukaryotes under certain conditions. Full article

Type 2 diabetes mellitus (T2DM) is a multifaceted metabolic disorder marked by impaired insulin action, pancreatic β-cell dysfunction, and the involvement of several interconnected mechanisms, including inflammation, oxidative stress, and epigenetic alterations. Despite progress in conventional therapies, achieving durable glycemic control and minimizing complications remain major challenges. This review discusses the emerging role of bioactive phytochemicals—such as curcumin, berberine, resveratrol, flavonoids, and polysaccharides—in modulating essential molecular pathways including AMPK, PI3K/AKT, and cAMP/PKA, which contribute to enhanced insulin sensitivity, glucose regulation, and β-cell protection. These natural compounds also influence gut microbiota modulation and epigenetic mechanisms, offering additional metabolic and anti-inflammatory benefits. This review synthesizes evidence from peer-reviewed studies published between 2000 and 2024, incorporating bibliometric trends showing an increasing research focus on phytochemicals for T2DM management. However, limitations such as low solubility, instability, and poor absorption restrict their clinical application. Advances in nanotechnology-based delivery systems, including nanoparticles, liposomes, and nanoemulsions, have shown potential to overcome these barriers by improving stability, bioavailability, and targeted delivery of phytochemicals. The integration of gut microbiota modulation with nanocarrier-enabled phytochemical therapy supports a precision medicine approach for managing T2DM. Preliminary clinical evidence highlights significant improvements in glycemic control and inflammatory status, yet further large-scale, well-controlled trials are essential to ensure safety, optimize dosages, and standardize combination regimens. Overall, phytochemical therapies, reinforced by nanotechnology and microbiota modulation, present a promising, safe, and holistic strategy for T2DM management. Continued interdisciplinary research and clinical validation are crucial for translating these advances into effective therapeutic applications and reducing the global diabetes burden. Full article

Neuronal synapses are the functional units of communication in the central nervous system. This review describes the molecular mechanisms regulating synaptic transmission, plasticity, and circuit refinement. At the presynaptic active zone, scaffolding proteins including bassoon, piccolo, RIMs, and munc13 organize vesicle priming and the localization of voltage-gated calcium channels. Neurotransmitter release is mediated by the SNARE complex, comprising syntaxin-1, SNAP25, and synaptobrevin, and triggered by the calcium sensor synaptotagmin-1. Following exocytosis, synaptic vesicles are recovered through clathrin-mediated, ultrafast, bulk, or kiss-and-run endocytic pathways. Postsynaptically, the postsynaptic density (PSD) serves as a protein hub where scaffolds such as PSD-95, shank, homer, and gephyrin anchor excitatory (AMPA, NMDA) and inhibitory (GABA-A, Glycine) receptors are observed. Synaptic strength is modified during long-term potentiation (LTP) and depression (LTD) through signaling cascades involving kinases like CaMKII, PKA, and PKC, or phosphatases such as PP1 and calcineurin. These pathways regulate receptor trafficking, Arc-mediated endocytosis, and actin-dependent remodeling of dendritic spines. Additionally, synapse formation and elimination are guided by cell adhesion molecules, including neurexins and neuroligins, and by microglial pruning via the complement cascade (C1q, C3) and “don’t eat me” signals like CD47. Molecular diversity is further expanded by alternative splicing and post-translational modifications. A unified model of synaptic homeostasis is required to understand the basis of neuropsychiatric and neurological disorders. Full article

This study developed a biodegradable dissolvable face mask incorporating liposomal kojic acid (KA) and licochalcone A from licorice extract (LE) to enhance skin delivery and performance. Liposomes were prepared by thin-film hydration method. The film matrix, composed of PVA/PVP/PEG400/HA, was optimized using factorial design to achieve suitable mechanical strength and rapid dissolution. The optimized mask, containing liposomal KA (1% w/v) and licochalcone A (0.025% w/v), was evaluated for antioxidant activity, ex vivo skin deposition, and short-term efficacy (Approval from the Institutional Review Board of Silpakorn University, Thailand; Ethics Approval No. REC 67.1001-146-7726/COA 68.0320-013 Date of registration: 20 March 2025). The optimized liposomes exhibited a mean particle size of 66–72 nm, entrapment efficiency above 65%, and a zeta potential of −12.5 mV (licochalcone A) and −1.67 mV (KA). Liposomal licochalcone A and KA showed potent antioxidant activity compared to their native forms. The optimized film dissolved within approximately 15 min on moist skin and showed favorable handling properties. Ex vivo studies revealed significantly higher skin deposition of both KA and licochalcone A from the liposomal mask compared with free and liposomal dispersions (p < 0.05). In a 7-day clinical evaluation, the mask significantly improved skin hydration and reduced melanin index (p < 0.05). No irritation or adverse reactions were observed, and user satisfaction was high. This liposomal dissolvable mask offered an effective, well-tolerated, and eco-friendly approach to enhancing skin brightness and hydration, supporting its potential as a sustainable cosmeceutical innovation. Full article

Neuropeptide FF (NPFF) belongs to the RF-amide peptide family and is homologous to gonadotropin-inhibitory hormone (GnIH). The NPFF precursor encodes two mature peptides, NPFF and NPAF (neuropeptide AF). Both peptides share the conserved C-terminal PQRFa motif. However, there is very limited information available on receptor cross-reactivity for NPFF and GnIH peptides in teleosts. As a first step, we cloned two cognate receptor genes for NPFF, designated as NPFFR2-1 and NPFFR2-2, in the flatfish species half-smooth tongue sole. Tissue distribution analysis revealed that npffr2-1 and npffr2-2 transcripts were present at high levels in the brain and pituitary gland, and at lower levels in some peripheral tissues. In vitro functional analysis indicated that NPFF significantly stimulated CRE-luc and SRE-luc activity in COS-7 cells expressing either NPFFR2-1 or NPFFR2-2. However, NPAF increased CRE-luc and SRE-luc activity only via NPFFR2-1. Moreover, NPFF exerted an inhibitory effect on NFAT-RE-luc activity in COS-7 cells transfected with NPFFR2-1, whereas NPAF elicited an evident stimulatory effect via NPFFR2-2. Neither GnIH1 nor GnIH2 altered CRE-luc activity in COS-7 cells transfected with NPFFR2-1 or NPFFR2-2; however, forskolin-induced CRE-luc activity was significantly reduced by these two peptides. Furthermore, neither basal nor forskolin-stimulated CRE-luc activity was modified by NPFF or NPAF in COS-7 cells expressing the GnIH receptor (GnIHR). Both GnIH1 and GnIH2 significantly increased SRE-luc activity in COS-7 cells expressing NPFFR2-1 or NPFFR2-2, and vice versa. Taken together, our findings provide novel evidence that both NPFF and GnIH peptides could exert their functions via three different receptors, and that PKA, PKC, and Ca²⁺ signaling pathways are potential mediators. Full article

Melanin produced in melanocytes contributes to photoprotection, oxidative stress reduction, immune regulation, and epidermal homeostasis, while its dysregulation underlies diverse pigmentary disorders. Natural products modulate melanogenesis by regulating tyrosinase activity, intracellular signaling pathways such as extracellular signal-regulated kinase/mitogen-activated protein kinase (ERK/MAPK) and cyclicAMP/protein kinase A/cAMP response element-binding protein (cAMP/PKA/CREB), and cellular redox balance. Anti-melanogenic effects have been reported for various fruit-derived phytochemicals, ginseng-based metabolites, and plant polyphenols, which act through direct enzymatic inhibition, suppression of melanoenic signaling, modulation of melanosome dynamics, and antioxidant or anti-inflammatory activities. Advances in delivery systems, including nano- and microencapsulation platforms, further enhance the stability and topical bioavailability of these compounds. In contrast, certain methoxylated flavonoids and phenolic constituents can stimulate pigmentation by sustaining melanogenic signaling and promoting microphthalmia-associated transcription factor (MITF)-driven transcription, emphasizing the context-dependent and bidirectional influence of natural substances on pigmentation outcomes. Collectively, these findings highlight the therapeutic potential of natural product-based modulators of melanogenesis while underscoring the need for mechanistic clarification, safety evaluation, and translational studies to ensure effective and controlled pigmentation management. This review summarizes the biological functions of melanin and examines natural strategies for regulating pigmentation. Full article

A novel series of benzoxazole-derived iminocoumarins was synthesized via a Knoevenagel condensation and fully characterized using NMR, UV–Vis spectroscopy, and computational methods. Their photophysical properties were systematically examined in solvents of varying polarity, revealing pronounced effects of both substituents and solvent environment on absorption maxima and intensity. Derivatives bearing electron-donating substituents on the coumarin core exhibited distinct and reversible pH-responsive spectral shifts, confirming their potential as optical pH probes. Experimental pK_a values derived from absorption titrations showed excellent agreement with DFT-calculated data, validating the proposed protonation-deprotonation equilibria and associated electronic structure changes. Structure–property relationships revealed that electron-donating groups enhance intramolecular charge transfer, while electron-withdrawing substituents modulate spectral response and stability. In parallel, the compounds were evaluated for antiproliferative, antiviral, and antifungal activities in vitro. Strong electron-donating substituents were associated with potent but non-selective cytotoxicity, whereas derivatives bearing electron-withdrawing groups displayed moderate and more selective antiproliferative effects against leukemia cell lines. Antifungal screening revealed moderate inhibition of phytopathogenic fungi, particularly for compounds with electron-withdrawing or methoxy substituents. Overall, these findings demonstrate that benzoxazole iminocoumarins represent a promising class of multifunctional heterocycles with potential applications as optical pH sensors and scaffolds for bioactive compound development. Full article

This study investigated the effects and mechanisms of broccoli extract containing more than 99.0% β-NMN (BRC) on UVB-induced skin damage, including moisture loss, oxidative stress, inflammation, wrinkle formation, and melanin production, using in vitro and in vivo models. BRC treatment significantly alleviated UVB-induced skin dehydration, oxidative stress, and inflammatory responses, as well as inhibited wrinkle formation and melanin synthesis. Mechanistically, BRC enhanced skin hydration and barrier function by upregulating hyaluronic acid synthases and genes related to sphingolipid metabolism, while simultaneously suppressing NF-κB signaling and COX-2 expression, thereby re-ducing inflammation. Moreover, BRC promoted collagen synthesis by activating the TGF-βR1/Smad3/Collagen pathway and prevented extracellular matrix degradation by inhibiting JNK/c-Fos/c-Jun/MMPs signaling. In addition, BRC modulated the cAMP/PKA/CREB/MITF/TRPs pathway, leading to reduced melanin production. These findings suggest that BRC supplementation may effectively protect against UVB-induced skin damage, supporting its potential application as a functional ingredient for skin health. Full article

The adenosine 3′,5′-cyclic monophosphate–protein kinase A (cAMP-PKA) signaling pathway is highly utilized in human physiology. It is a crucial component of development and is vital to cellular function in nearly all tissues. Indeed, genetic mutations to cAMP-PKA machinery are found in many pathologies, including multiple cancers, cardiac myxoma, neurodevelopmental disorders, and hypercortisolism. Cyclic AMP and PKA were first identified as vital components in cortisol synthesis over 50 years ago, yet the cellular mechanisms connecting PKA to cortisol production are still not well understood. This article will review evidence for PKA’s roles in adrenal gland zona fasciculata steroidogenesis and consider recent studies of the stress hormone disease adrenal Cushing’s syndrome to synthesize a current model for cAMP-PKA actions in cortisol production. Full article

Profiling the blood–brain barrier (BBB) permeability of bioactive molecules during early drug development is critical for optimizing their pharmacokinetic profile. The in vivo ability of a compound to cross the BBB is measured by the log BB parameter; however, its determination requires costly and time-consuming animal experiments. This study aimed to develop a novel in vitro method for high-throughput prediction of log BB values. The approach combines experimental data from open-tubular capillary electrochromatography (CEC) and automated potentiometric titrations, including the CEC retention factor (k′), electropherograms, and physicochemical parameters pK_a and log D_7.4. The k′ parameter reflects BBB permeability using a capillary internally coated with liposomes that mimic a biological membrane. Preliminary CEC analyses were conducted for 25 neutral drugs at pH 7.4, revealing a promising correlation between the permeability parameters log k and log BB. The validation was extended to 57 ionized drugs, with additional determination of pK_a and log D_7.4. A regression model was developed: log BB = −2.45 + 0.1k′ + 0.3logD_7.4 + 0.27pK_a (R² = 0.64). Furthermore, the analysis of CEC electropherograms enabled the machine learning-based rapid classification of compounds using Dynamic Time Warping, k-Nearest Neighbors, and the Bag-of-SFA-Symbols in Vector Space model, yielding an accuracy of 0.81 and an F1_weighted score of 0.8. Full article

Knee osteoarthritis significantly reduces quality of life due to difficulties with locomotion. The objective assessment of gait parameters can provide guidance for developing therapeutic programs, and wearable sensors are becoming increasingly common for this purpose. The Movement Kinematics Analysis System (MoKA) utilizes the Inertial Measurement Unit, which enables gait analysis in non-laboratory settings. The aim of the study was to determine gait parameters in women scheduled for knee replacement immediately before surgery, along with determining the measurement reliability. Seventy-six women were enrolled in the study (research group n = 25; control group n = 51). The participants completed the 6MWT with gait monitoring via the MoKA system. A comparison of pain intensity before and after the 6MWT revealed differences in p < 0.001. A comparison between the groups revealed differences in distance and step count. Pain intensity was negatively correlated with distance (R = −0.44) and the number of steps (R = −0.44), but did not affect the average length of steps (R = 0.05). The overall consistency assessment (AC) demonstrated good internal consistency. The qualitative ICC assessment indicated moderate reliability for three measurements, good for one, and excellent for the remaining measurements. It can be assumed that the assessment of biomechanical gait parameters using a system equipped with an IMU meets the criteria for measurement reliability. The gait of women with KOA scheduled for total knee replacement surgery is flattened and slowed, which may provide guidance for the use of appropriate postoperative exercises to achieve appropriate gait biomechanics. Full article

The red fluorescent protein mCherry is one of the most widely used fluorescent proteins in biology. Here, we have changed the chromophore chemistry by converting the thioether group of M66 to a thiol group through mutation to cysteine. The new variant, termed mCoral (due to its orange fluorescence hue), has similar brightness to mCherry but improved resistance to hydrogen peroxide. The variant is also responsive to pH with low and high pKa forms that have distinct spectral properties, which DFT analysis suggests is due to protonation state changes in the newly introduced thiol group, as well as the phenol group. The structure of mCoral reveals that the M66C mutation creates a space within the β-barrel structure that is filled by a water molecule, which makes new polar interactions, including the backbone carbonyl group of F65. Molecular dynamics simulations suggest that this additional water molecule, together with local solvation around the chromophore, could play a role in promoting planarity of the full conjugated system comprising the chromophore. The mCoral chromophore makes slightly more H-bonds with water than mCherry. The main water exit point for mCherry is also narrower in mCoral, providing a potential explanation for increased resistance to hydrogen peroxide. Overall, a small structural change to mCherry has resulted in a new fluorescent protein with potentially useful characteristics and an insight into the role of dynamics and water in defining the structure–function relationship in red fluorescent proteins. Full article

Parkinson’s disease (PD) is a complex neurodegenerative disorder characterised by progressive motor and non-motor impairment, in which current therapies remain symptomatic and fail to halt dopaminergic neuron loss. Growing evidence linking metabolic dysfunction, type 2 diabetes, and neurodegeneration has renewed interest in glucagon-like peptide 1 (GLP-1) receptor agonists as potential disease-modifying agents. While several recent reviews have explored the role of incretin-based therapies, the present work provides an integrative perspective by combining a mechanistic analysis of GLP-1 signalling pathways with a model-specific synthesis of preclinical findings and an appraisal of clinical translational relevance. We consolidate evidence across PI3K/Akt, MAPK/ERK, cAMP/PKA–CREB, and AMPK pathways, emphasising their convergence on mitochondrial homeostasis, proteostasis, neuroinflammation, and synaptic resilience. To enhance translational clarity, we summarise preclinical studies across major PD models, evaluate dose comparability and blood–brain barrier penetration, and identify pharmacokinetic and mechanistic factors that may explain divergent clinical outcomes. We also compare the therapeutic potential of key GLP-1 agonists, including exendin-4, liraglutide, semaglutide, lixisenatide, and emerging dual agonists. By integrating biochemical, preclinical, and clinical domains, this review provides a comprehensive framework for interpreting the current evidence and guiding the future development of incretin-based neuroprotective strategies in PD. Full article

This study compared the gonadotropin gene sequences (LH and FSH subunits) of Cynomolgus and Rhesus monkeys and produced recombinant single-chain LHβ/α and FSHβ/α proteins. The α- and FSHβ-subunit sequences were identical between species, while LHβ showed only minor synonymous differences. The recombinant hormones were successfully expressed and shown to be mainly N-glycosylated. Recombinant monkey FSHβ/α activated cAMP signaling in human FSH receptor-expressing cells, confirming its biological activity. β-arrestin 1 was found to have dual roles: its absence increased cAMP signaling (negative regulation), but it was required for ERK1/2 activation. ERK activation depended mainly on the cAMP/PKA pathway. Human and rat FSH receptors displayed different ERK activation timing, indicating species-specific signaling behavior. Overall, the study establishes a reliable system for producing functional recombinant monkey gonadotropins and clarifies how β-arrestin 1 differentially regulates FSH receptor signaling. Full article

Obesity is linked to metabolic dysfunction-associated steatotic liver disease (MASLD), but the molecular mechanisms and effective treatments remain unclear. This study investigated whether ST32db, an inducer of activating transcription factor 3 (ATF3), affects lipid metabolism in MASLD. An in vitro model was established involving the treatment of HepG2 cells with 1 mM oleic acid (OA) with or without 20 µM ST32db. In an in vivo model, C57BL/6 mice were fed a high-fat diet (HFD) for 18 weeks to induce obesity and treated or not with ST32db (1 mg kg⁻¹). ST32db significantly decreased intracellular lipid accumulation in OA-treated HepG2 cells. In these cells, ST32db remarkably decreased mRNA and protein levels of adipogenesis- and lipogenesis-related genes and increased mRNA levels of adipose triglyceride lipase (ATGL), a lipolytic enzyme. In HFD-fed mice, the ST32db treatment significantly decreased the liver weight, serum triglycerides, and fat vacuole and triglyceride accumulation in the liver. Livers from these mice also showed significantly decreased CCAAT/enhancer-binding protein β mRNA and protein levels, increased ATF3 mRNA and protein and ATGL mRNA levels, and increased levels of phosphorylated AMP-activated protein kinase (AMPK) and protein kinase A (PKA). These findings suggest that ST32db may exert protective effects against MASLD through activating hepatic AMPK and PKA pathways. Full article