Search Results (2,660)

Schiff bases are widely studied for their biological activities, yet structure–activity relationships governing their anticancer potential remain insufficiently understood. In this work, eight structurally diverse imine derivatives (A–H) were evaluated for their cytotoxic, biochemical, and biomolecular interactions in human cancer cells. Their antiproliferative effects were assessed in HeLa, A549, and LS174T cell lines, with MRC-5 fibroblasts used as a non-malignant control. Cytotoxicity screening identified three compounds (A, B, and F) with the highest potency, prompting further mechanistic investigation. Cell cycle analysis revealed G1 arrest and accumulation of sub-G1 populations for all three derivatives, with compound B additionally increasing S-phase content and compound F inducing G2/M arrest. All compounds reduced intracellular ROS levels and caused significant DNA damage at subtoxic concentrations. Western blot analysis demonstrated downregulation of HIF-1α and PDK3, suggesting disruption of hypoxia-associated metabolic signaling. Fluorescence quenching experiments showed strong binding of the active compounds to bovine serum albumin (K_a ≈ 10⁶ M⁻¹), and molecular docking supported stable interactions near tryptophan-adjacent binding regions. Collectively, these findings indicate that selected Schiff bases exert multi-target anticancer activity by modulating oxidative stress, DNA integrity, cell-cycle progression, and metabolic adaptation pathways, warranting further investigation of their therapeutic potential. Full article

Cadmium (Cd) is a typical pollutant with strong toxicity even at low concentrations. In the marine environment, Cd is a problem of magnitude and ecological significance due to its high toxicity and accumulation in living organisms. The clam Meretrix meretrix is a useful bioindicator species for evaluating heavy-metal stress. This study investigated the extent of recovery from Cd²⁺-induced oxidative and immune impairments in M. meretrix gills achieved by short-term depuration. Clams were exposed to 3 mg/L Cd²⁺ for six days or three days followed by three days of depuration, and the Cd contents, morphological structure, osmoregulation, oxidative stress, and immune responses in the gills were evaluated. The results showed that gill Cd contents increased with exposure, reaching 9.857 ± 0.074 mg·kg⁻¹ on day 3 but decreased slightly to 8.294 ± 0.056 mg·kg⁻¹ after depuration, while reaching 18.665 ± 0.040 mg·kg⁻¹ on day 6 after continuous exposure. Histological lesions, including lamellar fusion, hemolymphatic sinus dilation, and ciliary degeneration, partially recovered after depuration. Reactive oxygen species (ROS) and malondialdehyde (MDA) levels decreased significantly, while DNA-protein crosslinking rate (DPC) and protein carbonyl (PCO) showed minor reductions. Total antioxidant capacity (T-AOC) and the activities of Ca²⁺/Mg²⁺-ATPase (CMA), cytochrome c oxidase (COX), succinate dehydrogenase (SDH), and lactate dehydrogenase (LDH) increased by over 10% during depuration, though these changes were not statistically significant. Lysozyme (LZM) activity and MT transcript levels increased progressively with Cd exposure, indicating their suitability as biomarkers of Cd stress. Acid and alkaline phosphatase (ACP, AKP) activities and Hsp70 and Nrf2 mRNA transcripts exhibited inverted U-shaped response consistent with hormetic response. ACP and AKP activity levels rose by more than 20% after depuration, suggesting partial restoration of immune capacity. Overall, Cd exposure induced oxidative damage, metabolic disruption, and immune suppression in M. meretrix gills, yet short-term depuration allowed partial recovery. These findings enhance understanding of Cd toxicity and reversibility in marine bivalves and reinforce the usage of biochemical and molecular markers for monitoring Cd contamination and assessing depuration efficiency in aquaculture environments. Full article

This study evaluated the fermentation of calabash fruit (Crescentia cujete L.) seeds over 0, 24, 48, and 72 h to produce a daddawa-type condiment. Samples were analysed for proximate composition, antinutritional factors, morphological characteristics, and microbial profiles. Fermentation significantly (p < 0.05) reduced moisture content from 16.37% to 7.67%, carbohydrates from 34.73% to 22.93%, and crude fibre from 7.13% to 3.10%, while protein increased from 12.39% to 21.99%, fat from 24.86% to 28.69%, and ash from 4.02% to 7.62%. Antinutritional factors were also markedly reduced, with phytate decreasing from 2.23 mg/g to 0.24 mg/g, tannins from 0.17 mg/g to 0.03 mg/g, trypsin inhibitors from 3.14 mg/g to 0.17 mg/g, and saponins from 16.86 mg/g to 3.21 mg/g. Morphological analysis revealed fragmented clusters with intergranular pores, and functional amine groups responsible for the characteristic pungent aroma were detected. Bacterial isolates were identified as Bacillus and Lysinibacillus spp., with DNA sequencing confirming Bacillus spp. as the dominant fermenting organisms. These findings demonstrate that fermentation improves the nutritional quality, reduces antinutritional factors, and enhances the functional and culinary potential of calabash fruit seeds as a condiment. Full article

Background/Objectives: Soroseris hookeriana, a Tibetan medicinal plant endemic to the high-altitude Qinghai–Tibet Plateau, possesses significant pharmacological value but lacks fundamental genomic characterization. This study aims to generate and comparatively analyse its complete chloroplast genome. Methods: Total DNA was sequenced, assembled with GetOrganelle, annotated with CPGAVAS2, and compared with eight Asteraceae species; phylogenetic placement was inferred with IQ-TREE from 21 complete plastomes. Results: The circular chloroplast genome is 152,514 bp with a typical quadripartite structure (LSC 84,168 bp, SSC 18,528 bp, two IRs 24,909 bp each). It contains 132 unique genes (87 protein-coding, 37 tRNA, 8 rRNA; 18 duplicated in IRs yield 150 total copies). Twenty-three genes harbour introns; clpP and ycf3 have two. Overall GC content is 37.73%, elevated in IRs (43.12%). Codon usage shows strong A/U bias at the third position; 172 SSRs and 39 long repeats are detected. IR-SC boundaries exhibit the greatest inter-specific variation, notably in ycf1 and ndhF. Conclusions: The complete plastome robustly supports S. hookeriana and Stebbinsia umbrella as sister species (100% bootstrap) and provides essential genomic resources for species identification, population genetics, and studies of high-altitude adaptation. Full article

The study aimed to evaluate bottom sediments as a promising source of probiotic bacteria for aquaculture applications. Bacillus strains were selected as the most suitable bacterial species for application in the food industry. Initially, seven Bacillus spp. strains were isolated from the intestinal contents of healthy sterlet specimens; however, none of them demonstrated high potential probiotic properties. Subsequently, bottom sediments were considered as a source of probiotic strains. In the bottom sediments, bacilli exist in a vegetative form and constitute an integral part of the microbial community. A total of 120 Bacillus spp. strains were isolated and comprehensively analyzed. Proteolytic and amylolytic activities were detected at moderate levels in almost all isolated strains. Most isolates exhibited low or negligible antioxidant, DNA-protective, and antimicrobial activities; however, a small group of strains showed high values of these properties. Principal component and cluster analyses indicated the co-existence of three life strategies of bacilli in bottom sediments. These findings highlight the high probiotic potential of bacilli from bottom sediments and support their suitability as novel probiotics for enhancing the health and productivity of aquatic organisms in aquaculture. Full article

White-nose syndrome (WNS) is an infectious disease of bats caused by the psychrophilic fungus Pseudogymnoascus destructans. Phenazine-1-carboxylic acid (PCA) is a microbial secondary metabolite with broad-spectrum antifungal activity. Previous studies show that PCA suppresses the growth of P. destructans at low concentrations, yet its mechanism remains unclear. Here, we evaluated the in vitro antifungal activity of PCA. We then investigated its potential mechanism using physiological and biochemical assays, as well as integrated transcriptomic and metabolomic analyses. PCA showed effective antifungal activity against P. destructans (EC₅₀ = 32.9 μg/mL). Physiological and biochemical assays indicated that PCA perturbed cell wall organization and increased membrane permeability, leading to leakage of intracellular contents. It also induced oxidative stress, DNA damage, and apoptosis. Multi-omics integration revealed that PCA markedly perturbed cell wall and membrane metabolism, virulence factor expression, and energy metabolism. It provoked oxidative stress while downregulating genes involved in the cell cycle, DNA replication, and repair. Together, these findings delineate the inhibitory effects of PCA on P. destructans in vitro, provide initial mechanistic insights into its antifungal action, and suggest that PCA merits further evaluation as a possible component of environmentally compatible strategies for WNS management. Full article

N₂-fixing bacteria have great potential to be used as biofertilizer in agriculture to promote plant growth via nitrogen fixation. In this study, a novel species Fontibacillus forbon sp. nov., with strain BL-9^T as the type strain, was isolated from the rhizosphere of Fraxinus chinensis. Strain BL-9^T was able to fix nitrogen and grow on nitrogen-free medium. Phylogenetic analysis of 16S rRNA gene revealed that strain BL-9^T was most closely related to Fontibacillus phaseoli BAPVE7B (98.03%), followed by Fontibacillus solani A4STR04 (96.72%), Fontibacillus panacisegetis (96.6%), Paenibacillus vini (96.6%), and Paenibacillus segetis DB13260 (96.57%). The phylogenomic tree supported that strain BL-9^T was most closely related to F. phaseoli BAPVE7B. The digital DNA-DNA hybridization (dDDH) and average nucleotide identity (ANI) between strain BL-9^T and its closely related type strain, F. phaseoli BAPVE7B, were 42.5% and 90.94%, respectively, which were below the values (70% for dDDH and 95% for ANI) for species discrimination. The DNA G+C content of strain BL-9^T was 49.7%. The genome of strain BL-9^T had a nif (nitrogen fixation) gene cluster containing 10 genes (nifB nifH nifD nifK nifE nifN nifX orf1 hesA nifV). The predominant fatty acid was anteiso-C15:0, the major menaquinone was MK-7, and the major polar lipid was diphosphatidylglycerol. Strain BL-9^T and its closely related species of Fontibacillus had some common and distinguished physiological characteristics. Based on genomic, phylogenetic, chemotaxonomic, and phenotypic features, strain BL-9^T represents a novel species of the genus Fontibacillus. The name proposed for this species is Fontibacillus forbon sp. nov., with the type strain BL-9^T. Full article

This study aims to investigate the differences in microbial community structure between fast-growing (FG) and slow-growing (SG) short-finned eels, Anguilla bicolor pacifica, using high-throughput 16S rDNA sequencing, and to evaluate the potential probiotic properties of Bacillus tropicus isolated from eel intestinal microbiota to enhance growth performance. High-throughput 16S rDNA sequencing revealed no significant differences in the α-diversity between FG and SG eels. Bacterial genera such as Cetobacterium, Clostridium, and Bacteroides were predominant in both groups, with Edwardsiella, Aeromonas, and Fusobacterium being more abundant in SG eels, suggesting a higher presence of potential pathogens. The analysis of the relative abundance of gut microorganisms revealed that SG eels harbored higher levels of potentially pathogenic bacteria, including Edwardsiella tarda and Aeromonas jandaei. In contrast, FG eels exhibited a greater abundance of the potential probiotic B. tropicus. Six strains of bacteria with relative abundance were isolated from the FG group, displaying superior digestive enzyme activity, including protease, lipase, amylase, cellulase, xylanase, and phytase, particularly strain FG2. Phylogenetic analysis confirmed that FG2 was closely related to B. tropicus. A virulence assessment confirmed the non-pathogenic nature of B. tropicus FG2, supporting its probiotic potential. Furthermore, feeding eels a diet supplemented with B. tropicus FG2 significantly enhanced growth performance, as evidenced by increased final weight percentages of weight gain and total production per tank (p < 0.05), while the proximate composition of the dorsal muscle showed an increase in lipid content (p < 0.05). These findings highlight B. tropicus FG2 as a promising probiotic for aquaculture applications. Full article

Multidrug-resistant (MDR) Enterobacter cloacae is a growing public health issue worldwide, highlighting the urgent need for alternative antimicrobial strategies. This study reports on a lytic phage, designated B1, isolated from sewage, which exhibits specificity and lytic efficiency against MDR E. cloacae. Morphological observation revealed that B1 possesses an icosahedral head (~54 nm) and a short tail (~13 nm). Phage B1 showed a narrow host range, demonstrated stability within a temperature range of 4–37 °C, tolerance to pH values between 5 and 11, and showed an excellent bacteriolytic capacity with a short latent period of less than 10 min and a burst size of approximately 150 PFU/initially infected cell, indicating a rapid lytic cycle and efficient replication capability. Whole-genome sequencing revealed that the phage genome consists of 40,163 base pairs of double-stranded DNA containing 52 open reading frames (ORFs) with a GC content of 52%. Comparative genome-wide analysis using VIRIDIC revealed that B1 shares 75% to 92% similarity with Escherichia phage IMM-002 (accession: NC_048071), Citrobacter phage SH4, and Cronobacter phage Dev2 (accession: NC_023558), but shares less than 70% similarity with other Enterobacter phages. According to ICTV criteria, B1 represents a new species within the same genus as T7-like phages belonging to Autographiviridae, subfamily Studiervirinae, genus Kayfunavirus. In addition, B1 lacks lysogeny-associated or virulence genes and exhibits potent lytic activity against multidrug-resistant E. cloacae, making it a promising candidate for phage therapy. These findings opened up our understanding of the diversity of T7-like phages and provided insights into their evolutionary adaptability and therapeutic potential. Full article

Invertebrate iridescent viruses (IIVs, family Iridoviridae) are icosahedral double-stranded DNA viruses that infect a wide range of invertebrates, particularly in humid and aquatic environments. During field trials in Chiapas, southern Mexico, larvae of the fall armyworm, Spodoptera frugiperda (Lepidoptera: Noctuidae), displayed an unexpected lavender iridescence, leading to the discovery of novel IIV isolates from this major agricultural pest. Restriction endonuclease analysis revealed evident diversity among isolates from individual infected larvae. Although one field experiment yielded inconclusive results, a second experiment revealed a positive association between IIV disease and SfMNPV infection, compared to a negative association with the prevalence of parasitoids, and no association with entomopathogenic nematodes (probably Hexamermis sp.). These findings require further investigation to determine the distinct ecological routes through which the virus may transmit across host species. IIV infection of S. frugiperda was also identified in Veracruz State, Mexico, and northern Argentina, revealing a previously unrecognized geographic and host range for these viruses. The genomic and evolutionary features of the three isolates from S. frugiperda were compared with those of two other lepidopteran isolates from Helicoverpa zea (IIV30C obtained from CSIRO) and Anticarsia gemmatalis (AgIIV). Genome sizes ranged between 196.1 and 205.4 kbp (~28% GC content), with several large inversions, and were rich in tandem repeats. The average amino acid identity of the complete genomes and phylogenetic analyses of 26 core gene sequences placed all five isolates within the genus Chloriridovirus, closely related to IIV22 and IV22a isolated from blackflies (Diptera) in Wales and a previously sequenced isolate of IIV30 from the USA. We conclude that these lepidopterans are all infected by closely related strains of the virus species Chloriridovirus simulium1 across their native geographical range. These findings highlight the unexpected ecological breadth and evolutionary adaptability of IIVs. Full article

Background: Oxidative stress is a key contributor to many chronic diseases. Natural biocompounds with antioxidant activity are of growing therapeutic interest. Brassica macrocarpa, a plant from the Brassicaceae family, has shown in vitro safety and antioxidant potential due to its rich content of glucosinolates and phenolics. However, in vivo, its effects remain poorly characterized. This study aimed to evaluate the in vivo safety and biological effects of Brassica macrocarpa leaf extract in zebrafish embryos and to assess its potential to counteract copper sulphate (CuSO₄)-induced oxidative stress. Methods: Zebrafish embryos were exposed to Brassica macrocarpa extract at concentrations from 125 to 2000 µg/mL. Embryonic mortality and malformations were monitored daily to determine sub-lethal concentrations (125–500 µg/mL) for further behavioural and biochemical analysis. Antioxidant properties were tested in a CuSO₄-induced oxidative stress model. Results: No teratogenic effects were observed over 96 h. Larvae showed normal swimming and no behavioural changes. Pre-treatment with the extract significantly reduced CuSO₄-induced ROS and NO production, modulated antioxidant enzyme (SOD, CAT) activity, and lowered lipid peroxidation and protein oxidation, slightly affecting DNA damage. Conclusions: Brassica macrocarpa extract in vivo appears safe at sub-lethal doses and shows promising antioxidant effects, suggesting its potential role in managing oxidative stress-related conditions. Full article

Microbial degradation of pectin is a fundamental process for the carbon cycle and a strategic approach for treating industrial residues. This study characterizes a novel marine bacterium, Paenarthrobacter sp. FR1, isolated from East China Sea intertidal sediment, which exhibits the ability to utilize pectin. Its draft genome (4.83 Mb, 62.92% GC content) is predicted to encode 4498 protein-coding genes. Genomic analysis revealed a rich repertoire of Carbohydrate-Active Enzymes (CAZymes) crucial for this process, including 108 glycoside hydrolases (GHs), 7 polysaccharide lyases (PLs), 35 carbohydrate esterases (CEs), and 11 auxiliary activities (AAs). Genomic analysis provides supportive evidence that FR1 may target both homogalacturonan (HG) and rhamnogalacturonan (RG) pectin domains, potentially through complementary hydrolytic and oxidative pathways. Phylogenomic analysis based on Average Nucleotide Identity (ANI, 83.56%) and digital DNA-DNA Hybridization (dDDH, 27.8%) confirmed its status as a potential novel species. Notably, FR1 is a rare Paenarthrobacter isolate with innate pectinolytic capability, a characteristic not previously documented in this genus. This strain’s unique enzymatic machinery highlights its importance in marine carbon cycling and provides a valuable biotechnological resource for degrading pectin-rich wastes. Full article

Background: The senescence of testicular Leydig cells (LCs) is a key cause of age-related testosterone deficiency, in which oxidative stress (OS) and mitochondrial dysfunction are critical driving mechanisms. We explore whether the bioactive peptide C248 of PRDX4, an intracellular antioxidant, exerts mitochondrial protection to ameliorate LCs’ function. Methods: Based on the antioxidant domains of the PRDX4 protein, small molecular peptides were designed, and bioactive peptide C248 stood out from the crowd. An OS-induced senescence model of LCs was constructed by treating the MLTC-1 cell line with hydrogen peroxide (H₂O₂). C248 peptide or nicotinamide mononucleotide (NMN), as the positive control, was administered in the culture medium. The cellular function-related indicators, including DPPH free radical scavenging rate, cell viability, testosterone level, hydrogen peroxide (H₂O₂) content, senescence-associated β-galactosidase (SA-β-gal) activity, 8-hydroxy-2′-deoxyguanosine (8-OHDG) level, and 4-hydroxynonenal (4-HNE) level, were evaluated. The mitochondrial function and structural indicators, such as mitochondrial membrane potential, ATP production, mitochondrial morphology, and mitochondrial DNA (mtDNA) copy number, were subsequently tested. Results: In vitro experiments confirmed that C248 could scavenge DPPH free radicals in a dose-dependent manner, reduce the levels of reactive oxygen species, and increase antioxidant enzyme activity in LCs (p < 0.01). Both C248 and NMN increased testosterone secretion and improved cell viability (p < 0.01). Both C248 and NMN increased mitochondrial morphology and quantity, mitochondrial membrane potential (p < 0.01), ATP production (p < 0.01), and mitochondrial DNA (mtDNA) copy number (p < 0.01). Conclusion: This study reveals that the small molecular C248, a bioactive peptide of PRDX4, is a new candidate molecule for intervening in LC senescence and confirms that mitochondrial protection is a key strategy for improving age-related testicular dysfunction. Full article

Gene conversion contributes to gene copy number changes, DNA mutations, and functional innovation and has been widely reported in three domains of life. However, it has hardly been described in Aspergillus, including industrially and commercially important or pathogenic fungi. Here, we revealed multiple sets of homologous genes located in a region of chromosome 1 of A. flavus, and its orthologous counterpart of A. oryzae. Phylogenetic analysis showed evidence of frequent gene (DNA) conversion between ectopic paralogs in each species, accompanied by prominent point mutations and DNA deletion (from several to hundreds of base pairs). At least two independent cases showed that the converted genes in A. oryzae have been repeatedly split into shorter genes by the introduction of stop codons, and then ectopic conversion rendered paralogous genes (regions) to have the same configuration of tandemly located new genes. Inference of nucleotide substitution and ancestral gene content showed that the conversion-affected regions have seen 3.48 times as many substitutions and 4–6 times as many gene losses compared to the non-affected regions. We predicted that a DNA loop between proximal regions, in the common ancestor and inherited by each species, facilitates ectopic gene (DNA) conversion and elevated rates of mutations and losses. Overall, we found that gene conversion proves to be a key factor resulting in genome instability, elevated gene evolutionary rates, and an effective avenue to produce new genes, likely leading to the speciation of two Aspergillus lineages. Full article

The genus Bizionia, a member of the Bacteroidota phylum, is considered a polyphyletic taxonomic group requiring a phylogenetic revision of its members. A novel strain 041-53-Ur-6^T was isolated from the cavity fluid of the sea urchin Strongylocentrotus intermedius from the Sea of Okhotsk. Analysis of the 16S rRNA gene sequence showed that 041-53-Ur-6^T belongs to the family Flavobacteriaceae, and its closest neighbor is [Bizionia] algoritergicola with 97.5% sequence similarity. Phylogenomic analysis confirmed the phylogenetic heterogeneity of the genus Bizionia and the clear separation of the genera “Algorimicrobium” and Hanstruepera. The inter-genus AAI values between them were 74.0–76.4%, which is slightly lower than the inter-species AAI values observed for each genus. The strain 041-53-Ur-6^T (= KMM 8389^T) formed a separated branch within the [B.] algoritergicola clade, demonstrating the highest ANI/AAI values of 80.1/81.0% with the strain [B.] algoritergicola APA-1^T. The dDDH values between strain KMM 8389^T and representatives of the genus “Algorimicrobium” ranged from 22.6% to 26.7%. Major fatty acids were iso-C_15:1 ω10c, iso-C_15:0 and iso-C_15:0 Δ2-OH. The polar lipids included a phosphatidylethanolamine, a phosphatidylglycerol, five unidentified lipids, two unidentified aminolipids, a phosphatidylcholine, and an unidentified aminophospholipid. The genome KMM 8389^T is a circular chromosome of 3,031,910 bp in size with a DNA G + C content of 33.5%. It comprises 2702 protein-coding genes and four rrn operons. Functional genomic analysis indicated the potential of KMM 8389^T for degrading starch, glycogen, and alginate due to the presence of genes encoding GH13, GH31, and GH65. Furthermore, KMM 8389^T possessed PLs 6, 7, 12, and 17, specialized for alginate, confirming the potential adaptation of this strain to algal substrates and surfaces. On the basis of the results of genotypic, chemotaxonomic, and phenotypic analyses, it is clear that the strain KMM 8389^T represents a novel species with [B.] algoritergicola, [B.] argentinensis, [B.] echini, [B.] hallyeonensis, [B.] myxarmorum, [B.] psychrotolerans, and [B.] sediminis as the nearest neighbors. These taxa are classified in a single novel genus, as Algorimicrobium algoritergicola gen. nov., comb. nov., A. argentinensis comb. nov., A. echini comb. nov., A. hallyeonensis comb. nov., A. myxarmorum comb. nov., A. psychrotolerans comb. nov., A. sediminis comb. nov., and Algorimicrobium bowmanii sp. nov. 041-53-Ur-6^T (=KMM 8389^T, =KCTC 72011^T). Full article