Search Results (1,649)

Excessive melanin accumulation induced by UV exposure and hormonal changes poses significant challenges to skin health, necessitating safe and effective tyrosinase inhibitors. Pearl and nacre powder have long been utilized in traditional Chinese medicine for skin whitening. Our previous study identified a tyrosinase inhibitory peptide (Ala-His-Tyr-Tyr-Asp) from Pinctada martensii nacre in silico; however, chemical modification strategies for enhancing bioactive peptide efficacy remain underexplored. The present study investigated the structure-activity relationship of NP-TIP-1 (Tyrosinase Inhibitory Peptide of Nacre Powder-1) through three chemical modifications (C-terminal amidation, N-terminal acetylation, and N-terminal palmitoylation). C-terminal amidation significantly improved tyrosinase inhibitory potency, reducing the IC50 value from 2.012 ± 0.088 mM to 0.979 ± 0.028 mM, while retaining thermal stability and copper ion chelating capacity comparable to the native peptide. In B16F10 melanoma cells, NP-TIP-1-NH₂ (C-terminally amidated NP-TIP-1) exhibited no cytotoxicity at concentrations up to 600 μM and concentration-dependently suppressed intracellular tyrosinase activity and melanin content. Mechanistic investigation revealed that NP-TIP-1-NH₂ treatment downregulates the mRNA and protein expression of TYR and TRP-1 without affecting MITF (Microphthalmia-associated Transcription Factor) or TRP-2, suggesting a potential regulatory mechanism independent of MITF-mediated transcriptional control. Non-targeted metabolomics further identified nucleotide metabolism, purine metabolism, and glycine/serine/threonine metabolism as the most significantly perturbed pathways, with cytosine and GMP downregulated while guanosine and guanine were upregulated. This study establishes NP-TIP-1-NH₂ as a promising candidate for multifunctional food preservatives and nutraceuticals, providing a strategic framework for C-terminal amidation as a structure-activity optimization approach for marine-derived anti-melanogenic peptides. Full article

Surface wettability is a critical factor influencing the biological performance of orthopedic Ti implants. The native TiO₂ film on Ti undergoes changes in wettability under ultraviolet (UV) irradiation. However, the limited tissue penetration of UV light compared with near-infrared (NIR) light restricts its potential clinical application. In this study, a black TiO₂ (b-TiO₂) coating with NIR-responsive wettability was fabricated directly on a Ti substrate using a one-step atmospheric plasma spraying process. Under 808 nm NIR irradiation, the water contact angle of the b-TiO₂ coating increased from 0° to 154.4 ± 4.0°, indicating a transition from a superhydrophilic to a stable superhydrophobic state. FTIR and XPS analyses showed that NIR-induced photothermal heating promoted the removal of surface hydroxyl groups and the passivation of oxygen-deficient sites, thereby driving the wettability transition. Among TiO₂ coatings with hydrophilic, intermediate-wettability, and hydrophobic surfaces, the hydrophobic coating effectively directed macrophage polarization toward the anti-inflammatory M2 phenotype and delivered slightly superior osteoblast activity. It also markedly inhibited Staphylococcus aureus adhesion, achieving an anti-adhesion efficiency of 98.61%. These findings demonstrate that NIR irradiation can regulate the wettability of plasma-sprayed b-TiO₂ coatings and provide concurrent immunomodulatory and antibacterial effects. This approach may support the development of light-responsive surfaces for orthopedic implants. Full article

A novel sulfated α-glucan (VpG), with an ultra-high molecular weight of approximately 2250 kDa and a sulfation degree of 18.6%, was previously isolated from Volutharpa ampullacea perryi and shown to alleviate dextran sulfate sodium (DSS)-induced ulcerative colitis in mice. However, the underlying mechanisms remain unclear. In the present study, we further characterized the structural features of VpG using scanning electron microscopy (SEM), atomic force microscopy (AFM) and UV-Vis spectroscopy, and evaluated its immunomodulatory effects in lipopolysaccharide (LPS)-stimulated RAW264.7 cells. SEM revealed a dense, porous surface with co-existing filamentous and flake-like structures, while AFM imaging showed that VpG adopted an irregular branched chain-like conformation. In functional assays, VpG significantly inhibited the production of pro-inflammatory cytokines, inducible nitric oxide synthase (iNOS) and toll-like receptor 4 (TLR4) in a dose-dependent manner. Flow cytometric analysis revealed that VpG downregulated LPS-induced expression of the M1 surface marker CD80, while Western blotting showed that VpG suppressed the phosphorylation of p38, ERK1/2, and JNK1/2/3, indicating blockade of the MAPK signaling pathway. In addition, VpG exhibited potent radical scavenging activity against hydroxyl and superoxide anion radicals, which is associated with its anti-inflammatory activity. Collectively, these findings indicate that VpG exerts its anti-inflammatory effects through the inhibition of M1 macrophage polarization and suppression of MAPK activation, with its antioxidant capacity potentially contributing to the overall effect. This study provides a mechanistic basis for understanding the anti-inflammatory action of VpG and supports its potential as a therapeutic candidate for ulcerative colitis. Full article

To improve the aging resistance of SBS-modified asphalt (SBSMA), this study prepared two metal oxide/montmorillonite nanocomposites, TiO₂/montmorillonite (TM) and CeO₂/montmorillonite (CM), and investigated their effects on the rheological properties and microstructure of SBSMA before and after long-term aging. The performance differences between the two nanocomposites under different aging modes were also compared. Conventional physical property tests, dynamic shear rheometer tests (temperature sweep and linear amplitude sweep), dynamic mechanical analysis (DMA), and fluorescence microscopy were employed to evaluate the physical properties, high- and low-temperature rheological properties, fatigue resistance, and the microscopic evolution of SBSMA. The results show that before aging, the incorporation of TM and CM significantly improved the high-temperature deformation resistance of SBSMA, enhanced the SBS polymer dispersion state, and promoted the formation of a continuous network structure of polymer phase. After long-term thermal-oxidative aging, both nanocomposites effectively retarded the aging of the asphalt matrix and the SBS network; CM exhibited superior thermal-oxidative aging resistance. After long-term ultraviolet (UV) aging, both nanocomposites also showed significant protective effects, and TM outperformed CM in UV aging resistance. In summary, TM and CM show differentiated advantages in UV protection and thermal-oxidative protection, respectively, providing a theoretical basis for the design of anti-aging materials for SBSMA based on service environments. Full article

The use of different marine resources, including various colouring agents, is rooted in human history. They have been used as nutrients and medicaments and in luxury products. Readily available marine biological pigments (MBPs) are considered inexpensive materials, since they can be used as colourants. MBPs form part of the ‘’blue technology’’ approach for industrial colouring applications, including staining, textile dyeing, and uses to give fashionable colours to luxury products. They serve as nutrient additives, cosmetic ingredients, and as parts of beauty products. Today, they still are broadly used in the context of diverse new applications. MBPs can be concentrated differently on the bodies of marine creatures, providing each pigment its unique colour and properties. MBPs like carotenoids can complement important cell activities, like photosynthesis. They can function independently or support other micro- and macromolecules. MBPs are essential for their host’s survival. Outside their primary hosts (in the context of uses on and in consumers’ corpora), they either stay unmodified or can be changed by association with specific micro- and macromolecules. A few types of MBPs have been extracted, purified, identified, and formulated as drugs or pure chemicals. MBPs share common properties, such as functioning as antioxidants, can protect against sunlight and UV waves, and can improve vision. They take part in health protection and disease treatment, including anticancer, anti-inflammatory, anti-neurodegeneration, anti-ageing, and anti-wrinkle functions, and can function as an antimicrobial. With many undiscovered properties, MBPs represent a source for de novo applications with innumerable chances that might offer mastery of the fields of colour-based applications. This review summaries the importance of MBPs and addresses important applicable properties that make them attractive for nutraceutical, medicinal, pharmaceutical, and cosmeceutical uses, in addition to various industrial applications, and discusses historical and contemporary facts that have attracted human attention, both in the past and today, along with setting out expectations for the future of MBPs. Full article

Citrullus colocynthis (L.) Schrad. (Cucurbitaceae) is a medicinal plant, renowned since antiquity, widely used in traditional medicine for the management of metabolic and inflammatory disorders: seed extracts particularly are reported for the management of rheumatoid arthritis, articular inflammation and skin wound recovery. Our aim was to comparatively evaluate the antioxidant and anti-inflammatory activities of aqueous and oily extracts obtained from mature and immature seeds, and to preliminarily assess their dermal tolerance and protective effects against induced inflammation and UV damage. Antioxidant activity was investigated in vitro using β-carotene bleaching and ferric reducing antioxidant power (FRAP) assays, whereas anti-inflammatory activity and anti-irritation effects were evaluated in vivo in a mouse model using the xylene-induced ear edema and the UV-induced skin irritation test. Oily extracts from both maturation stages showed marked inhibition of β-carotene oxidation, while the aqueous extract of immature seeds exhibited the highest ferric reducing capacity; on the other hand, fixed oils demonstrated a significantly greater inhibitory effect on oedema, suggesting a higher efficacy in modulating acute inflammatory responses. Results showed how C. colocynthis seed maturity and extraction solvent influence the bioactive potential of these ingredients for phytotherapeutic and dermo-functional applications, supporting a possible use against wrinkle formation and UV-induced skin alterations. Full article

Rising temperatures and the occurrence of heat waves due to climate change can increase the risk of various skin disorders. Moreover, elevated temperatures worsen oxidative damage and inflammation caused by other climate change stressors, such as UV exposure. Consequently, there is growing interest in innovative solutions to protect skin health from the effects of pollution and climate change stressors. Among natural cosmeceuticals, carotenoids are recognized for their antioxidant and anti-inflammatory properties. This study evaluated the thermoprotective effects of Hematococcus lacustris (the microalga formerly called Hematococcus pluvialis) extract (HLE), which is considered the richest natural source of carotenoid astaxanthin, against acute hyperthermia, which mimics the conditions of heat waves. In addition, we separately assessed the effects of HLE against UVA and hydrogen peroxide stress, complementing the antioxidant profile of the extract under study. The evaluation was conducted using in vitro tests on human HaCaT keratinocytes and the nematode Caenorhabditis elegans, which is a model organism sensitive to environmental stressors. The treatment of HaCaT keratinocytes with HLE counteracted the intracellular formation of reactive oxygen species and cytotoxicity induced by hyperthermia, UVA, and hydrogen peroxide exposure. Under the same experimental conditions, HLE also restored the impaired expression of stress-sensitive genes, such as matrix metalloproteinase-1, in HaCaT keratinocytes and promoted wound closure mimicking the process of re-epithelization. Lastly, experiments in C. elegans confirm that HLE reduces heat stress-induced oxidative damage and preserves motility, supporting a systemic protective effect consistent with dietary uptake of the extract. These findings suggest that HLE, rich in carotenoid astaxanthin, can protect keratinocytes against oxidative damage and cytotoxicity induced by thermal stress, indicating its potential role in mitigating thermal aging. Full article

Nelumbo nucifera Gaertn. is a rich source of bioactive compounds, and has been extensively investigated for its antioxidant and anti-inflammatory properties. However, despite its broad pharmacological potential, detailed molecular-level insights into the interactions of its phenolic and flavonoid constituents with key skin-aging-related enzymes remain limited. Therefore, this study employed an integrated in silico and in vitro approach to systematically evaluate the anti-aging potential of phenolic and flavonoid compounds derived from N. nucifera. Molecular docking was performed to investigate their binding interactions with tyrosinase, elastase, and collagenase. Compounds exhibiting the most promising inhibitory profiles were further subjected to molecular dynamics (MD) simulations for 100 ns and density functional theory (DFT) analyses at the B3LYP/6-31G(d,p) level of theory to elucidate their structural stability and electronic properties. The computational results revealed favorable binding affinities, stable complex formation, and electrostatic features supporting hydrogen bond interactions. In vitro enzyme inhibition assays demonstrated that hesperidin exhibited inhibitory activity against tyrosinase, collagenase, and elastase, with IC₅₀ values of 3.43 mM, 2.26 mM, and 0.55 mM, respectively. Kojic acid was used as a positive control for tyrosinase, while epigallocatechin gallate (EGCG) was used as a positive control for both collagenase and elastase. Additionally, hesperidin exhibited enzyme-inhibitory activity and preliminary intrinsic UV absorption. This compound warrants further investigation, specifically regarding its stability and performance within standardized cosmeceutical formulations. Full article

The modulation of ZnO physicochemical properties through Mn doping represents a promising strategy for the development of multifunctional nanomaterials with enhanced biological performance. In this study, we investigate how the nominal Mn concentration influences both the physicochemical properties and antibacterial, antibiofilm, and anti-virulence activities of ZnO nanoparticles (NPs). Mn-doped ZnO nanoparticles containing nominal Mn from 2.5 to 10 mol% were synthesized through a simple wet-chemical approach and characterized by UV–Vis, Raman, TEM, EDX, and EELS analyses. The resulting ZnO-based NPs showed average dimensions of 3.7–4.8 nm, while increasing Mn incorporation produced measurable changes in optical response and morphology of nanoparticles. Antibacterial activity was evaluated against Gram-positive and Gram-negative bacterial models by assessing planktonic growth inhibition, biofilm formation, and pyocyanin production. The sample with the highest Mn amount (Mn₁₀-ZnO) markedly enhanced antibacterial performance by reducing MIC₉₀ from 150 to 37.5 μg/mL against Staphylococcus aureus and from 300 to 75 μg/mL for Pseudomonas aeruginosa. Mn doping also enhanced biofilm inhibition and produced a progressive reduction in pyocyanin synthesis. These results establish a concentration-dependent relationship between Mn concentration, nanoparticle properties, and antibacterial performance, highlighting the potential of Mn-doped ZnO nanoparticles for the development of anti-infective biomaterials, including antimicrobial coatings for implantable medical devices. Full article

Skin photoaging is primarily induced by ultraviolet (UV) radiation and is accompanied by extracellular matrix (ECM) degradation, abnormal pigmentation, and loss of skin elasticity. Excessive melanin synthesis represents a key cause of pigmentary skin disorders. Natural polyphenols with dual skin-whitening and anti-photoaging activities have attracted increasing attention as cosmetic ingredients. This study examined the effects of polyphenol-enriched fraction from the brown alga Sargassum fusiforme (SFP). Zebrafish embryos and human melanoma A375 cells were used to evaluate the depigmenting efficacy of SFP, while UVA-induced human dermal fibroblasts (HDFs) were employed to assess its anti-photoaging activity. SFP significantly decreased melanin levels in both models in a dose-dependent and reversible manner by suppressing tyrosinase activity. In terms of anti-photoaging effects, SFP markedly suppressed UVA-induced matrix metalloproteinases (MMPs) expression and elevated key ECM components, including type I collagen, elastin, and hyaluronic acid. In conclusion, SFP exerts dual beneficial effects by attenuating melanogenesis via tyrosinase inhibition and alleviating photoaging damage by suppressing MMPs to protect ECM. These results provide a scientific foundation for the use of SFP as a dual-purpose natural cosmetic ingredient with significant potential in the cosmetics sector. Full article

Ultraviolet (UV) radiation is a major environmental factor contributing to photoaging, oxidative stress, inflammation, DNA damage, and photocarcinogenesis. Conventional UV filters, although widely used in sunscreen formulations, are associated with limitations including photoinstability, photocatalytic ROS generation, potential toxicity, and environmental concerns. In recent years, plant-mediated nanomaterials have emerged as promising multifunctional photoprotective systems, combining UV attenuation with antioxidant, anti-inflammatory, and biologically adaptive properties. Plant extracts are increasingly used as reducing and stabilising agents in the green synthesis of metal and metal oxide nanoparticles. Among these, ZnO and TiO₂ serve as established inorganic UV filters, whereas Ag and Au nanoparticles have primarily been investigated for their antioxidant, anti-inflammatory, antimicrobial, and ROS-modulating properties, which may indirectly enhance photoprotection. In parallel, plant-derived organic nanoparticles and herbal nanocomposites have demonstrated enhanced biocompatibility and multifunctional performance. This review critically examines the current landscape of plant-mediated photoprotective nanomaterials, focusing on the mechanistic interplay among optical UV attenuation, reactive oxygen species (ROS) modulation, and cellular signalling regulation. Particular emphasis is placed on structure–function relationships governing nanoparticle size, surface chemistry, bandgap properties, antioxidant behaviour, and biological interactions. The review further discusses translational challenges, including reproducibility, standardisation, scalability, long-term safety, regulatory classification, and limitations in benchmarking. Importantly, current evidence suggests that no single material system simultaneously optimises UV-blocking efficiency, ROS control, biocompatibility, and industrial scalability, highlighting the need for multifunctional hybrid design strategies. Finally, future perspectives involving predictive nanoengineering, computational modelling, machine learning-guided optimisation, and adaptive photoprotective systems are discussed as emerging directions for next-generation sustainable photoprotective technologies. Full article

Lung cancer remains a leading cause of cancer-related mortality worldwide, underscoring the need for safer and more effective therapeutic strategies. In this study, zinc oxide nanoparticles (ZnO NPs) were synthesized via a green, biogenic approach using Lantana camara L. flower aqueous extract and evaluated for their anticancer potential against human non-small cell lung cancer (NSCLC) NCI-H460 cells. The biosynthesized ZnO NPs were characterized using UV-visible spectroscopy, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), Transmission electron microscopy (TEM), energy-dispersive X-ray analysis (EDX), X-ray diffraction (XRD) and particle size analysis, confirming the formation of nanocrystalline ZnO. LC-MS profiling of the Lantana camara flower extract revealed the presence of several bioactive phytochemicals, including phenolic compounds, terpenoids, fatty acids, and alkaloids, which may contribute to the reduction and stabilization of ZnO NPs during green synthesis. Cytotoxicity assessment of ZnO NPs using MTT and trypan blue exclusion assays revealed a dose-dependent reduction in cell viability, with an IC₅₀ value of 50 µg/mL. Mechanistic investigations demonstrated that ZnO NP exposure induced significant oxidative stress, evidenced by increased nitric oxide, lipid peroxidation, and reactive oxygen species levels, along with depletion of intracellular glutathione. Apoptotic cell death was further confirmed by nuclear DNA fragmentation, mitochondrial membrane depolarization, and G0/G1 phase cell cycle arrest. Quantitative real-time PCR analysis revealed upregulation of the pro-apoptotic genes Bax and p53, accompanied by downregulation of the anti-apoptotic gene Bcl-2, indicating activation of a mitochondrial-dependent intrinsic apoptotic pathway. Collectively, these findings suggest that Lantana camara L. flower-mediated ZnO nanoparticles induced apoptotic responses associated with oxidative stress in NSCLC cells, highlighting their ability as an eco-friendly nanoplatform for further anticancer investigations. Full article

To address the critical limitations of traditional photothermal–responsive epoxy–based shape memory polymers (ESMPs), such as poor compatibility and cyclical instability, a series of side–chain azobenzene (Azo)–functionalized linear ESMPs (EPDm) were successfully synthesized via chemical bonding. Highly rigid 4–aminoazobenzene (Azodm) units were covalently integrated into the Bisphenol A–type epoxy backbone as functional photo–responsive side chains. Systematic characterizations confirmed that the glass transition temperature (T_g) of the EPDm polymers could be precisely tuned from 41.53 °C to 53.26 °C by adjusting the Azodm content. Benefiting from the proposed homogeneous covalent architecture, the EPDm films exhibited superior photothermal sequential behavior and remarkable shape memory stability despite a slight reduction in tensile strength (≈10–12 MPa). Under 365 nm UV irradiation, the pre–stretched EPDm₁₀ specimen achieved a rapid macroscopic bending angle of over 150° within 15 s, driven exclusively by the trans–to–cis molecular photoisomerization of the Azo side chains well below the matrix T_g. Furthermore, standard shape memory cycles demonstrated excellent shape fixity (R_f > 98%) and recovery (R_r > 95%) ratios, alongside exceptional anti–fatigue performance with minimal strain variance (≈5%) over consecutive cycles. This work establishes a robust and high–efficiency molecular design strategy for photo–thermally sequentially responsive shape memory polymers, offering immense potential for smart actuators and flexible electronics. Full article

Fenugreek seed oil contains bioactive constituents of interest for functional-food applications, but its susceptibility to environmental degradation may limit processing and storage. This study developed an alginate–chitosan encapsulation system and examined how chitosan molecular weight affected the physicochemical properties and in vitro bioactivity of the resulting formulations. Fenugreek seed oil was obtained by mechanical pressing and Soxhlet extraction, yielding 2.81% and 5.50% (v/w), respectively. The oil was incorporated into calcium-alginate beads (T₁), which were left uncoated or coated with high-molecular-weight chitosan (HMC; T₂) or low-molecular-weight chitosan (LMC; T₃). The formulations were characterized by color measurement, microscopy, scanning electron microscopy, Fourier-transform infrared spectroscopy, thermogravimetric analysis, and particle-size analysis of oil droplets released from the polymer matrix. Free and encapsulated oil samples were also exposed to UV-C irradiation and evaluated using antioxidant assays, an albumin-denaturation inhibition assay, and an α-amylase inhibition assay. Dry-product recovery ranged from 76.72% for T₂ to 94.79% for T₁, with T₃ showing a higher recovery than T₂. SEM showed that T₂ had the smoothest and most uniform dried morphology. FTIR spectra were consistent with interactions between alginate and chitosan while retaining characteristic bands associated with the oil. The chitosan-coated formulations also showed altered thermal-degradation profiles compared with alginate alone. After irradiation, T₃-UV showed DPPH radical-scavenging activity of 63.03% and albumin-denaturation inhibition of 94.95%, whereas T₂-UV showed the highest α-amylase inhibition. These findings indicate that chitosan molecular weight influences formulation recovery, morphology, thermal behavior, and measured in vitro activity. Further work using matched non-irradiated controls, standardized oil-equivalent concentrations, release testing, and gastrointestinal models is required before functional-food delivery claims can be established. Full article

In this study, emodin was used as the starting material to synthesize two novel ligands, L1 and L2, containing bipyridine or phenanthroline moieties. Seven metal complexes (1–7) were obtained through coordination with Co, Rh, Ru, and Pt ions. Their structures were confirmed via NMR, HRMS, UV–Vis, IR, HPLC and SC-XRD analyses. The MTT assay showed that L1 and complex 2 selectively inhibited HepG-2 cells, with IC₅₀ values of 8.77 μM and 6.10 μM, respectively. Both compounds exhibited stronger activity than cisplatin (9.05 μM) and low toxicity toward normal 293T cells. Mechanistic studies demonstrated that they induced G2/M phase arrest by regulating Cyclin B1 and P21 expression, which was accompanied by ROS and Ca²⁺ accumulation, mitochondrial membrane potential disruption, and activation of the Caspase-9/3 cascade. Complex 2 showed superior antitumor activity to L1, and this finding was further supported by molecular docking analysis. In sum, Rh(III) complex 2 was identified as a selective and mechanistically defined anti-hepatocellular carcinoma lead compound, providing a potential strategy for the development of natural product-based metal anticancer agents. Full article