Search Results (1,413)

Background/Objectives: mRNA display technology has emerged as a powerful platform for discovering macrocyclic peptides against intractable proteins. However, direct screening against the “undruggable” transcription factor MYC using this approach remains largely unexplored. In this study, we aimed to integrate tyrosinase-mediated cyclization with mRNA display to identify novel macrocyclic peptide inhibitors targeting MYC. Methods: We performed mRNA display combined with tyrosinase-mediated cyclization to generate macrocyclic peptides targeting MYC. Antiproliferative activity was assessed in MYC-dependent tumor cells using CCK8 assay. C-terminal fusions with a TAT-derived cell-penetrating peptide were generated to enhance cell membrane permeability. Binding affinities were measured by bio-layer interferometry (BLI). MYC transcriptional activity was evaluated by RNA sequencing (RNA-seq) analysis of canonical MYC target genes. Results: The identified macrocyclic peptides exhibited potent antiproliferative activity against MYC-dependent tumor cells, with half-maximal inhibitory concentration (IC₅₀) values in the micromolar range. Fusion with the TAT peptide improved antiproliferative potency, yielding IC₅₀ values of 1–3 μM in MYC-dependent cell lines. BLI assays confirmed dose-dependent binding of the peptides to MYC, with dissociation constants (Kd) in the micromolar range. Furthermore, RNA-seq analysis revealed significant downregulation of canonical MYC target genes upon treatment with the TAT-fusion macrocyclic peptide, indicating specific suppression of MYC transcriptional activity. Conclusions: This work establishes the feasibility of using mRNA display to target the “undruggable” protein MYC and identifies a panel of macrocyclic peptides as promising lead candidates for further optimization toward targeted therapies for MYC-driven cancers. Full article

Skin aging is associated with oxidative stress, extracellular matrix degradation, and dysregulation of melanogenesis, leading to wrinkles, loss of elasticity, and hyperpigmentation. Natural plant-derived compounds have attracted increasing interest as multifunctional cosmetic ingredients due to their antioxidant and anti-aging properties. Mai-Kae-Den-Klong (MKDK), a traditional Thai longevity herbal formula composed of Albizia procera (Roxb.) Benth., Cyperus rotundus L., Diospyros rhodocalyx Kurz, Piper nigrum L., Streblus asper Lour., and Tinospora crispa (L.) Hook.f. & Thomson, has historically been used to promote vitality and healthy aging; however, its potential application as a cosmetic anti-aging ingredient remains scientifically unexplored. Therefore, this study investigated the anti-aging potential of MKDK extract using integrated enzyme-based bioassays and in silico approaches. Phytochemical profiling of the ethanolic extract was performed using LC-MS analysis, revealing diverse bioactive constituents, including flavonoids, phenolic glycosides, alkaloids, and terpenoids, with (−)-epicatechin, procyanidin B1, and piperine identified as major metabolites. Antioxidant activity was evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging assays, while inhibitory activities against tyrosinase, collagenase, elastase, and hyaluronidase were assessed to determine skin anti-aging potential. The extract exhibited strong antioxidant activity, with IC₅₀ values of 17.23 ± 2.11 µg/mL for DPPH and 11.87 ± 1.77 µg/mL for ABTS assays. In addition, the extract demonstrated inhibitory effects against tyrosinase (IC₅₀ = 41.25 ± 1.56 µg/mL), elastase (IC₅₀ = 49.51 ± 3.69 µg/mL), collagenase (IC₅₀ = 61.54 ± 2.88 µg/mL), and hyaluronidase (IC₅₀ = 63.74 ± 6.32 µg/mL), suggesting multifunctional anti-aging properties associated with skin brightening and extracellular matrix preservation. Network pharmacology analysis predicted multiple aging-related signaling pathways, particularly the FoxO signaling pathway, which is associated with oxidative stress regulation and longevity. Molecular docking analysis further demonstrated favorable binding affinities of procyanidin B1, epicatechin, and piperine toward skin-aging-related enzymes, supporting their potential contribution to the observed bioactivities. Overall, these findings suggest that MKDK possesses promising cosmeceutical potential as a natural multifunctional anti-aging ingredient and provides scientific support for the application of traditional Thai herbal formulations in cosmetic and skin health products. Full article

Plants of the genus Astragalus are recognized as rich sources of bioactive compounds with antioxidant and therapeutic potential; however, European species remain less explored than the well-known Astragalus membranaceus (Fisch.) Bunge. The aim of this study was to compare the phytochemical composition and in vitro biological activity of selected Astragalus species occurring in Poland (A. cicer L., A. glycyphyllos L., A. membranaceus). Phenolic compounds in methanolic extracts obtained from the roots and aerial parts were analyzed using spectrophotometric methods and UHPLC–DAD–ESI/TOF–MS. Antioxidant activity was evaluated using DPPH, ABTS, FRAP, CUPRAC, metal chelation, superoxide radical scavenging, and lipid peroxidation (TBARS) assays. Additionally, enzyme inhibition toward α-amylase, lipase, hyaluronidase, tyrosinase, and butyrylcholinesterase was assessed. The root of A. membranaceus exhibited the highest total phenolic content (199.84 ± 3.64 mg GAE/g extract) and the strongest antioxidant activity (DPPH IC₅₀ = 36.53 ± 1.22 µg/mL; ABTS IC₅₀ = 26.31 ± 0.03 µg/mL), as well as the most pronounced α-amylase inhibition (IC₅₀ = 17.78 ± 1.16 µg/mL). It also demonstrated moderate protective effects against AAPH-induced lipid peroxidation. The herb of A. cicer showed moderate radical scavenging capacity and the most effective inhibition of lipid peroxidation at higher concentrations. Extracts of A. glycyphyllos displayed weaker radical scavenging but notable metal-chelating properties. Selected extracts also exhibited moderate inhibitory activity against tyrosinase and butyrylcholinesterase. A. membranaceus remains the most potent source of phenolic compounds and antioxidant activity; European species such as A. cicer and A. glycyphyllos represent promising, locally available alternatives and may be used in phytotherapy and functional products. Full article

Tyrosinase is a pivotal therapeutic target for hyperpigmentation disorders, yet current inhibitors frequently exhibit limited potency and suboptimal safety. Here, we employed structure-based virtual screening of an FDA-approved drug library against a refined human tyrosinase homology model, identifying methotrexate and selinexor as potent anti-melanogenic candidates. Both compounds markedly suppressed cellular tyrosinase activity and melanin synthesis (IC₅₀ < 1 µM) in MNT-1 melanoma cells. Mechanistically, they orchestrate a multi-pronged downregulation of microphthalmia-associated transcription factor (MITF) by attenuating cAMP/PKA/CREB signaling, promoting β-catenin degradation, and accelerating MITF proteolysis via AKT/ERK activation. Additionally, they bolster the intracellular antioxidant defense system. These findings unveil a sophisticated regulatory network and suggest that with strict control of systemic exposure through optimized topical formulations, these FDA-approved agents could be further investigated as potential localized treatments for pigmentary disorders. Full article

The valorization of agri-food by-products generated during juice extraction represents a key strategy within circular economy frameworks, as it reduces the environmental impact of waste disposal while creating added value and improving the food supply chain. In this work, five betaine-based natural deep eutectic solvents (NaDES) differing in their hydrogen-bond donors, namely citric acid, lactic acid, acetic acid, glycerol, and ethylene glycol, were used for the green extraction of blueberry pomace, a largely underutilized by-product that is nevertheless rich in bioactive compounds. The extracts were characterized by liquid chromatography coupled with diode-array and tandem mass spectrometric detection, allowing targeted profiling of anthocyanins and non-anthocyanin phenolics, including phenolic acids, flavonoids, and phenolic aldehydes. The extraction performance of NaDES was benchmarked against conventional solvents (water and ethanol) to evaluate differences in selectivity and efficiency toward distinct phenolic classes. Antioxidant capacity was determined using DPPH and ABTS radical scavenging assays. Among the NaDES systems, the betaine–citric acid NaDES extract exhibited notable phenolic recovery together with marked radical scavenging activity. After evaluating its inhibitory activity against elastase and tyrosinase, enzymes involved in the skin aging process, the selected NaDES extract was incorporated into a natural-based antiaging cosmetic formulation, and its main physicochemical properties were assessed to verify suitability for topical application. This study demonstrated that the use of NaDES represents an environmentally friendly and sustainable approach to transform blueberry by-products into high-value, safe, and ready-to-use cosmetic functional ingredients without the need for solvent removal. Full article

Background/Objectives: Dioscorea batatas Decne (yam), which contains various bioactive compounds, has been utilized in the cosmetics industry, while most of the peel of D. batatas (DBP) is discarded without further use. Recent studies have shown that DBP contains higher levels of bioactive substances than the rhizome flesh. The aim of this study was to evaluate the skin biological activities of DBP extracts obtained using 70% ethanol (70% EtOH DBP), 95% ethanol (95% EtOH DBP), and ethyl acetate (EA DBP), with particular attention to their antioxidant-associated protective effects. Methods: Skin-related bioactivities of DBP extracts prepared using ultrasonic extraction were evaluated using in vitro tyrosinase and matrix metalloproteinase-1 (MMP-1) assays, alpha-melanocyte-stimulating hormone (α-MSH)-induced melanogenesis in B16F10 cells, ultraviolet B (UVB)-irradiated HaCaT viability assays, and Western blot analysis of pro-collagen type I alpha 1(Pro-COL1A1) and MMP-1 in HDF cells. In addition, the ABTS and DPPH radical scavenging activities of DBP extracts and representative DBP derivatives were assessed. Results: DBP extracts inhibited tyrosinase activity in vitro and reduced melanogenesis in B16F10 cells. DBP extracts also protected skin cells from UVB by increasing the viability of UVB-irradiated HaCaT cells. In UVB-irradiated HDF cells, DBP extracts restored Pro-COL1A1 expression and suppressed MMP-1 levels. Additionally, DBP extracts inhibited MMP-1 activity in a concentration-dependent manner. The DBP extracts themselves exhibited ABTS and DPPH radical scavenging activities, with EA DBP showing the highest vitamin C equivalent antioxidant capacity among the tested extracts. Representative DBP-derived phenanthrene compounds also showed radical scavenging activities, supporting the antioxidant potential of peel-derived phytochemicals. Conclusions: These findings indicate that DBP extracts possess skin-whitening and anti-photoaging effects and suggest that these protective activities may be associated with the antioxidant potential of both DBP extracts and DBP derivatives. Full article

Tyrosinase-related protein 1 (Tyrp1) is a melanosomal glycoprotein required for eumelanin biosynthesis through the oxidation of 5,6-dihydroxyindole-2-carboxylic acid (DHICA). Pathogenic variants in Tyrp1 cause oculocutaneous albinism type 3 (OCA3), but the molecular basis by which individual substitutions impair Tyrp1 stability and activity remains incompletely understood. Here, we examined wild-type Tyrp1 and three missense variants associated with OCA3: R356Q and R326H as OCA3-related variants, and D308N as a benign control; these were under conditions relevant to melanosome maturation. To assess stability, we developed a urea-induced unfolding assay in which His-tagged Tyrp1 variants were immobilized to Ni-NTA magnetic beads before chemical denaturation. R356Q was the most destabilized variant, with a ΔΔG of 0.695 kcal/mol at pH 5.0 (acidic conditions) and 1.998 kcal/mol at pH 7.4 (near-neutral conditions) relative to wild-type. R326H showed intermediate destabilization, whereas D308N behaved similarly to wild-type. DHICA oxidation assays in the presence of MBTH showed about 20% reduced catalytic activity for R356Q, particularly under acidic conditions. Molecular dynamics simulations and ligand docking were consistent with these findings and indicated that R356Q increases conformational flexibility and perturbs structural integrity. In contrast, glycosylation reduced conformational fluctuations and enhanced stability across Tyrp1 and mutant variants examined. Together, these results show that pH, glycosylation, and disease-associated substitutions collectively modulate Tyrp1 folding energetics and catalytic competence and identify R356Q as a strongly destabilizing OCA3 variant. By defining how disease-associated Tyrp1 substitutions affect protein stability and function, this study may provide a framework for interpreting genotype–phenotype relationships and improving molecular diagnosis of OCA3. Full article

This study is the first to demonstrate fluctuations in major phenolics and biofunctional properties under various extraction conditions of Korean winter spinach (Allseason cultivar) leaves. In contrast to earlier reports on summer- or greenhouse-cultivated spinach, which mainly relied on HPLC-DAD or LC-MS profiling and one or two bioactivity assays, the present work combines UPLC-Q-TOF-MS/MS with NMR-based structural confirmation of three major flavone glucuronides (11–13) and integrates five complementary bioactivity assays (DPPH, ABTS, FRAP, DNA protection, and tyrosinase inhibition) within a single optimization framework. A 50% methanol extract yielded twelve phenolics (patuletin, spinacetin, spinatoside, jaceidin, and methylenedioxyflavone-glucuronide derivatives) elucidated by UPLC-Q-TOF-MS/MS, with the isolated major phenolics 11–13 further verified by NMR. Total phenols and total flavonoids of biofunctional characteristics varied significantly depending on the solvent system. The optimal extraction conditions (50% methanol, 72 h, 35 °C) resulted in the highest phenolic levels of phenolics 11–13 (total: ~6.5 mg/g) and bioactivities (DNA protection > ABTS > tyrosinase inhibition > FRAP > DPPH, at 500 μg/mL). PCA and hierarchical clustering distinguished extraction profiles, with 50–70% methanol extracts forming clear clusters. Among the isolated phenolics, phenolic 12 showed the strongest antioxidant activity (DPPH IC₅₀ = 57.6 μM; ABTS IC₅₀ = 21.9 μM). These findings suggest that spinach leaves are a valuable source of bioactive phenolics for nutraceutical applications under optimized extraction conditions. Full article

Tomato processing generates large amounts of by-products, with seeds representing an underutilized yet protein-rich fraction. This study investigated direct enzyme-assisted protein extraction from non-defatted tomato seeds. Various enzymes, enzyme/substrate ratios, pre-treatments, and incubation temperatures were evaluated and optimized. An enzyme/substrate ratio of 5% (w/w) was found to be optimal, with proteases alone outperforming cell wall-degrading enzymes and two-step extraction strategies. Bromelain, Protamex, and Trypsin, for the first time applied directly to non-defatted tomato seeds, achieved the highest protein recoveries (average 110.56 mg BSA eq/g DW). Among them, Trypsin also produced the highest reducing sugar content (25.07 mg GLU eq/g DW), indicating effective cell wall disruption. Digestates obtained from defatted and non-defatted tomato seeds showed comparable protein contents, demonstrating that defatting was unnecessary. Avoiding the defatting step improved process sustainability by reducing solvent use and energy consumption without significantly affecting protein extraction efficiency. Incubation at 37 °C was preferred over 60 °C, as similar yields were achieved under milder conditions while also reducing energy consumption by approximately three-fold (54,340 kJ vs 150,480 kJ for a 1000 L water-based scale-up simulation). These digestates showed significantly higher antioxidant and, for the first time in tomato seed extracts, anti-tyrosinase activities compared with controls. Protamex-derived samples exhibited the highest bioactivities (7.40 mg AA eq/g DW; 101.36 μg KA eq/g DW). Compared to conventional alkaline–acid extraction followed by enzymatic digestion, the direct enzymatic approach provided higher protein recovery. Overall, this method represents a sustainable strategy for producing bioactive peptide-rich extracts for food and non-food applications. Full article

Corn husk, a prevalent agricultural byproduct, remains an underutilized source of bioactive compounds. This study investigated the influence of extraction solvents (water, 50% ethanol, and 95% ethanol) and techniques (maceration, reflux, ultrasound-assisted extraction) on the phytochemical profiles and biological activities of corn husk. The results revealed that water extraction produced the highest total phenolic content, whereas 95% ethanol extraction yielded the greatest total flavonoid content and the most potent antioxidant activity in DPPH testing. In contrast, ultrasound-assisted water extraction exhibited the most potent nitric oxide inhibition (94.62 ± 2.13%) and tyrosinase inhibition (IC₅₀ = 7.54 ± 0.27 mg/mL), indicating anti-inflammatory and skin-lightening potential. This extract showed anti-collagenase activity (91.49 ± 4.01%), outperforming ascorbic acid (29.79 ± 1.00%) and EGCG (82.27 ± 1.00%), though its anti-hyaluronidase activity was limited. Cytotoxicity testing revealed cytotoxicity at 10 mg/mL, while the HET-CAM assay confirmed non-irritation at the same level. These findings underscore that ultrasound-assisted water extraction is a safe and successful technique for obtaining bioactive-rich extracts. This study supports the transition of corn husk from agricultural waste to a high-value, safe, and multifunctional natural ingredient for the cosmetic, pharmaceutical, and functional food industries. Full article

Life expectancy in high-income countries is increasing, leading to a higher incidence of age-related neurodegenerative diseases. To address this urgent medical need, several molecular targets have been identified, including advanced glycation end products (AGEs) and tyrosinase. Given the well-established role of diet in counteracting degenerative processes, this study aimed to identify a potential food ingredient with combined anti-tyrosinase and anti-glycative properties. Acanthus mollis L. was selected based on its inclusion in the BelFrIt list and its known content of tyrosinase inhibitors, such as benzoxazinones and verbascoside. Extraction of A. mollis leaves was optimized using a design of experiments approach, comparing microwave- and ultrasound-assisted techniques. Optimal conditions were achieved using microwave-assisted extraction with ethanol 80%, 80 °C, one cycle, drug-to-solvent ratio of 10 mL/g. The optimized extract (at 5 mg/mL) inhibited tyrosinase activity by approximately 47%, increasing to 58% after chlorophyll removal. Moreover, the extract reduces AGEs formation in presence of methylglyoxal, with an activity at 1 mg/mL comparable with that of a well-known anti-glycative agent. A similar trend was observed in the reduction in methylglyoxal and glyoxal levels. Overall, these results support the potential of the optimized A. mollis extract as a functional food ingredient to counteract aging-related neurodegeneration. Full article

For the first time, a regulatory network linking melanin, genes, pathways, and edible quality was constructed for 138 Auricularia cornea strains sourced domestically and internationally. This marks the inaugural study of A. cornea spanning from cellular to physical-mechanical properties. Correlation analysis between melanin and edible quality traits (hardness, springiness, cohesiveness, gumminess, chewiness, and resilience) revealed that hardness, cohesiveness, and gumminess increased with rising melanin content, while springiness correspondingly decreased. Genome-wide association analysis identified 15,597,589 SNP loci. A total of 39 genes related to food quality were annotated, including one melanin-related lacquer enzyme gene, ACW004924. Real-time quantitative PCR validation of key genes identified for melanin and edible quality traits revealed results consistent with those from correlation analysis. The lacquer enzyme genes ACW004736, ACW006232, which regulate melanin synthesis, and the tyrosinase genes ACW001451, ACW002443, and ACW001003 were also identified in edible quality traits. These genes perform similar functions in GO-enriched metabolic processes, catalytic activity, and cellular structural complexes, as well as in KEGG-enriched pathways such as carbon metabolism and polysaccharide synthesis. They catalyze melanin synthesis and promote interactions between melanin and cell wall polysaccharides, chitin, and structural proteins, thereby stabilizing the cellular scaffold structure, jointly mediating the effect of melanin on the edible quality of A. cornea. The results supplement the downstream regulatory chain of catalytic enzymes and edible quality in the γ-L-glutaminyl-3,4-dihydroxybenzene (GDHB) pigment synthesis pathway, and form an information network of melanin synthesis, cell wall structure optimization, and edible quality regulation. Full article

Verbascum species have long been recognized for their medicinal properties; however, detailed studies on the endemic species Verbascum wiedemannianum Fisch. & C.A. Mey. remain limited. The purpose of this study is to evaluate the antioxidant and anti-tyrosinase activities of essential oil (EO) and methanol extract (ME) derived from V. wiedemannianum, an endemic species from Türkiye. The EO was obtained by hydrodistillation, and its chemical composition was characterized using GC-FID and GC/MS. The principal constituents of the EO were palmitic acid (27.3%), myristic acid (11.9%), 1-octadecanol (13.0%), and pentacosane (6.6%). LC-MS/MS analysis of the ME identified luteolin and chrysoeriol derivatives as the predominant compounds. The antioxidant potential of both the EO and ME was evaluated using three assay systems based on electron transfer reactions: the Folin–Ciocalteu reagent, the Trolox equivalent antioxidant capacity assay, and the cupric ion (Cu²⁺) reducing antioxidant capacity assay. The potential skin care effects of the EO and ME were further evaluated using a tyrosinase inhibition assay. Across all the assays, the ME consistently showed notable activities, whereas the activity of the EO was less clearly defined. These findings indicate that the ME of V. wiedemannianum contains bioactive compounds with potential applications in natural antioxidant and skin care formulations. Further studies are warranted to clarify its therapeutic uses. Full article

The invasive plant Tithonia diversifolia is a promising source of botanical insecticides, yet the mechanisms by which its active compounds impair insect physiology remain incompletely characterized. This study investigated the effects of 6-methoxyluteolin (6-ML), a flavonoid isolated from T. diversifolia, on melanization and cuticle integrity in Spodoptera litura larvae. Cuticle melanization, mediated by tyrosinase-catalyzed oxidation of tyrosine-derived substrates, is essential for cuticle sclerotization and immune defense in insects. Whether 6-ML directly targets this pathway has not been previously examined at the biochemical and histological level. Tyrosinase activity and melanin content were measured across 3rd–6th-instar larvae exposed to a concentration gradient of 6-ML (1.625–100 μg/mL). Histological sections of 4th- and 5th-instar larvae were prepared by paraffin embedding and hematoxylin and eosin (H&E) staining. 6-ML significantly reduced tyrosinase activity and melanin content in a concentration-dependent manner across all instars examined. Histological analysis revealed progressive cuticle thinning and loss of pigmentation granules with increasing 6-ML concentration. These findings provide the first biochemical and histological evidence that 6-ML targets the melanization pathway in S. litura, supporting its potential as a melanization-inhibiting botanical insecticide. Full article

Extracted from Ganoderma lucidum mycelium, the developed β-1,3;1,6-glucan rich polysaccharides have the potential to be used during the industrial production of health food products due to their inhibition of metabolic syndrome, immunomodulatory and antitumor activities and other health benefits. Ganoderma active polysaccharides (GAP) have also been found to promote skin health, particularly due to their antioxidant and anti-aging properties. The present study investigates the skin-protective properties of polysaccharides purified from Ganoderma mycelium cultivated using stress-tolerance technology and a fully plant-based medium. The effects of the GAP are investigated in both in vitro and human studies. The results of the study indicate that the developed GAP effectively inhibit 32.4% of tyrosinase activity and 30.6% of melanin production in B16F10 cells. Furthermore, in scratch assays using NIH 3T3 cells, these GAP also promote cell migration and wound healing. In human studies, GAP demonstrated no potential for skin irritation while effectively reducing skin wrinkles, enhancing skin brightness, diminishing erythema, and increasing epidermal hydration. In hot-flux patch-induced erythema experiments, these GAP were found to be capable of alleviating erythema severity by up to 48%. The present study demonstrates that GAP, which can be produced industrially using innovative technologies and is rich in highly water-soluble β-1,3;1,6-glucan with a triple-helix structure, holds potential for application in the skincare industry. Full article