Search Results (401)

Chlorella and Arthrospira (spirulina) are aquatic microalgae of increasing nutraceutical interest due to their dense bioactive composition and multi-target biological activity. This narrative review provides a comparative, mechanistically integrated synthesis of molecular mechanisms and clinical evidence related to their supplementation. Current data indicate that both microalgae converge on three central regulatory axes: activation of Nrf2-dependent antioxidant responses, attenuation of NF-κB-driven inflammatory signaling, and modulation of AMP-activated protein kinase (AMPK)/protein kinase B (AKT)-mediated metabolic pathways. Spirulina demonstrates stronger mechanistic links to intracellular signaling and more consistent clinical evidence for improvements in lipid profile, insulin sensitivity, and systemic inflammation. In contrast, chlorella provides complementary effects, particularly in antioxidant capacity, blood pressure regulation, gut microbiota modulation, and detoxification-related contexts. Their bioactive components—including phycocyanin, carotenoids, polysaccharides, and peptides—act synergistically to influence mitochondrial function, immune homeostasis, and metabolic resilience. While clinical findings are generally consistent, heterogeneity in study design and product standardization limits definitive conclusions. Overall, chlorella and spirulina emerge as complementary multi-pathway biological response modulators with potential applications in preventive and integrative medicine. Full article

Ceramidases hydrolyze ceramides to fatty acids and sphingolipids, but their role in fungal response to stress remains unclear. We investigated the function of neutral ceramidase (nCDase) response to aromatic fungicide (carvacrol, cuminaldehyde, and isoniazid) stress in Neurospora crassa. Comparative analysis of the wild-type strain, Δnc and OEnc showed that nCDase enhanced fungicide resistance through multiple mechanisms. nCDase improved β-1,3-glucan synthesis (30% increase), decreased membrane permeability, elevated superoxide dismutase and catalase activities, and promoted carotenoid accumulation (50%), which collectively improved stress tolerance. Δnc exhibited disruption of cellular integrity, altered fatty acid profiles (elevated oleic acid, reduced total fatty acids), and increased fungicide sensitivity. Collectively, these findings established that nCDase as a key regulator of cell wall dynamics, lipid homeostasis, and antioxidant defense, thereby facilitating fungal adaptation to abiotic stress. This study identified the role of nCDase in the response to aromatic fungicide stress and laid foundation for inhibiting pathogenic fungi in agricultural production and food preservation. Full article

Chloroidium saccharophilum is a resilient green microalga with a broad ecological distribution and an increasing biotechnological interest due to its tolerance of extreme environmental conditions. In this study, a sample of C. saccharophilum from the Laguna Blanca aquifer (Magallanes, southern Chile) was physiologically and phylogenetically characterized. This is the first confirmed evidence of this strain in the Southern Cone. Molecular identification based on ITS rDNA sequencing and ITS2 secondary structure analysis confirmed its taxonomic location, showing high similarity with reference strains and no compensatory base changes. Growth performance was analyzed under controlled laboratory conditions and under outdoor desert cultivation in the Atacama Desert, focusing on temperature, salinity, nutrients limitation, and high solar irradiance operational conditions. The strain exhibited optimal growth at 22 °C under laboratory conditions and demonstrated a strong tolerance to high salinity (150 g L⁻¹ NaCl). Outdoor raceways cultivation revealed a negative relationship between temperatures above 25 °C and biomass accumulation, while nutrients depletion and strong irradiance caused moderate carotenoid accumulation. However, the low amount of carotenoid yields remained constant, even under combined stress conditions. In general, the results highlight the ecological adaptability and the stress tolerance of C. saccharophilum, supporting its potential application in saline bioprocesses and bioremediation. Nevertheless, the limited production of carotenoid synthesis suggests that additional or combined stress strategies will be required to enhance the production of high-value metabolites. This study expands the biogeographical knowledge of C. saccharophilum and provides a physiological baseline for future optimization studies in extreme and Mars-analog environments. Full article

Weed interference and herbicide-induced phytotoxicity, particularly from HPPD inhibitors such as tembotrione, represent significant limitations to yield stability in grain sorghum. Developing strategies to enhance crop tolerance without compromising weed control is of high practical interest. This study tested the hypothesis that a commercial Ascophyllum nodosum-based biostimulant can mitigate tembotrione-induced oxidative stress and phytotoxicity in sorghum without compromising the weed-control activity of the herbicide. Sorghum plants at the V4 phenological stage (four fully expanded leaves) were subjected to five treatments: (1) untreated control; (2) biostimulant application alone; (3) tembotrione application alone; (4) simultaneous application of tembotrione and biostimulant; and (5) tembotrione followed by biostimulant application after six days of application (6 DAT). After 10 days of treatment, photosynthetic pigment synthesis, primary photochemistry, gas exchange, antioxidant metabolism, phytotoxicity levels, growth parameters, and yield indices were evaluated. The results support the hypothesis that A. nodosum-based biostimulants can act as effective mitigating agents. The biostimulant sustained carotenoid levels and preserved the stability of the photosynthetic apparatus (PSII), counteracting HPPD enzyme inhibition caused by the herbicide. Isolated biostimulant application upregulated net photosynthesis by 60%, while simultaneous co-application with tembotrione preserved membrane integrity and the leaf area index. Furthermore, the efficacy of the mitigation strategy was highly time-dependent, as simultaneous co-application proved superior to the delayed (6 DAT) intervention. From an agronomic perspective, the biostimulant reduced visual injury and restored the grain number per plant to control levels under simultaneous co-application, although the final yield of combined treatments did not differ statistically from either the untreated control or the treatment of tembotrione alone. This study shows that the integration of A. nodosum extracts into the chemical management of sensitive crops represents a viable biotechnological strategy to enhance herbicide selectivity and yield stability. Full article

Chroococcidiopsis sp. was isolated from the endolithic habitat of the Atacama Desert (northern Chile), one of the most challenging-to-life polyextreme environments on Earth. The photosynthetic machinery of microorganisms inhabiting this environment is supposed to be highly adapted to cope with the intense solar radiation of the area. Thus, PAR-red light ranging from 100 to 900 µmol photon·m⁻²·s⁻¹ has been investigated as a strategy to enhance culture productivity and stimulate the synthesis of bioactive molecules in Chroococcidiopsis sp. A control culture was maintained under white light at 100 µmol photon·m⁻²·s⁻¹. The results revealed that red light was utilized more efficiently than white light of similar irradiance, and its modulation enhanced both growth and photosynthetic activity of the cyanobacterium. Furthermore, Chroococcidiopsis sp. appeared to activate mechanisms to mitigate photooxidative stress produced by excess light energy. Specifically, increasing light irradiance induced photoacclimation responses, characterized by a decrease in chlorophyll content and a concomitant increase in carotenoid accumulation, likely aimed at reducing photon flux transduced to photosynthesis. Additionally, scytonemin synthesis was enhanced under high irradiances, contributing to dissipating excess light energy. Overall, this study demonstrates that modulation of red-light irradiance effectively improves the growth of Chroococcidiopsis sp. while promoting the accumulation of antioxidant compounds—primarily carotenoids and, to a lesser extent, scytonemin. Full article

Carotenoids are natural pigments of high industrial value, with recognized antioxidant properties, and are widely used in the food, cosmetic, and pharmaceutical industries. Oleaginous yeasts, such as Rhodotorula glutinis, represent a promising alternative for the sustainable production of these compounds through submerged fermentation, compared to their extraction from plant sources or chemical synthesis. This study aimed to optimize culture conditions to maximize biomass and carotenoid production in R. glutinis P4M422. To this end, the effects of various culture factors, including light, carbon-to-nitrogen (C/N) ratio, temperature, pH, and glycerol addition, on cell growth and pigment biosynthesis were evaluated. The results showed that agitation speed and C/N ratio are key variables in system performance, significantly influencing both growth and carotenoid accumulation. Under the established optimal conditions (210 rpm, C/N ratio of 50, red light, and 30 °C), a maximum volumetric yield of 343.1 mg/L and a productivity of 4.8 mg/L/h were achieved, representing a substantial improvement in process efficiency. These values position the R. glutinis P4M422 strain as a competitive alternative for the biotechnological production of carotenoids. Taken together, these findings confirm the efficiency of submerged culture as a platform for obtaining high-value-added biopigments and reinforce the potential of microbial fermentation systems as a sustainable, scalable, and controllable strategy for their production. Full article

Stressful effects on agriculture are of paramount importance in the 21st century. Water deficiency is considered a major constraint in crop succession, particularly for maize. Therefore, this study aimed to investigate the potential roles of brassinolide (BL) and silicon (Si) in mitigating biotic (incidence of pests and diseases) and abiotic stresses (naturally occurring water deficit) in maize grown after soybean harvest. The field experiments were conducted over two growing seasons on a Rhodic Haplustox in the Cerrado, Goiás, Brazil. A randomized complete block design was employed in a 5 × 2 factorial arrangement, with five BL doses (0.000, 0.050, 0.100, 0.150, and 0.200 mg L⁻¹) and two Si treatments (absence and presence), each with four replicates. BL was applied immediately when the soil moisture in the 0–0.20 m layer reached 16.25%, corresponding to the crop’s critical water threshold. This specific phenological point corresponded to the R₂ stage in the first off-season and the V₁₀ stage in the second off-season. Si applications were performed at the V₃ and V₈ stages. BL application enhanced growth, as well as physiological and metabolic performance by increasing protein synthesis and sugar content, thereby maintaining relative water content, sustaining antioxidant enzyme activity, and reducing lipid peroxidation under water-deficit conditions. The BL doses that achieved the highest yields were 0.149 mg L⁻¹ (R₂ stage) in the first off-season and 0.134 mg L⁻¹ (V₁₀ stage) in the second off-season. Si application effectively reduced pest damage and disease severity while improving plant water status. However, in the second off-season, a significant BL × Si interaction was limited to carotenoids, pheophytinization index, and disease severity. These results indicate that the combined use of BL and Si provides a promising strategy to enhance maize resilience by integrating BL-mediated yield promotion with Si-driven physical and biotic protection under adverse environmental conditions. Full article

Tomato high pigment-2 (hp-2^dg, hp-2, and hp-2^j) mutant lines are characterized by mutations in the DE-ETIOLATED1 (SlDET1; Solyc01g056340) gene. SlDET1 is responsible for encoding a nuclear protein that acts as a negative regulator involved in light signaling, repressing photomorphogenesis. These tomato mutant lines are known for increased levels of antioxidant pigments in fruits, such as flavonoids and carotenoids, compared to the wild-type fruits. In this study, CRISPR/Cas9, followed by the non-homologous end joining mechanism of repair (NHEJ), was used to target the SlDET1 gene and investigate whether the effects of these mutations could mimic the effects of hp-2 mutant lines, improving the nutritional features of tomato fruits. Our results indicated that mutations generated by CRISPR/Cas9 NHEJ in the hp-2 and hp-2^j regions (exon 11) resulted in significant changes in the SlDET1 coding and protein sequences. These mutations caused a low survival rate of edited sprouts and regenerated plants with a very compromised capacity of allelic heritability of these mutations for the following generations. However, regenerated plants containing these site-specific mutations in the SlDET1 gene showed higher levels of phytochemicals in ripe fruits. Furthermore, these edited plants also showed an upregulation of structural genes involved in the synthesis of these biocompounds. Although the SlDET1 gene could be considered an interesting target gene for the nutritional improvement of tomato fruits, our results showed that mutations within its exon 11 are quite critical and can induce severe perturbations in plant physiology, with a compromised possibility to develop new stable edited lines. Full article

Fungal pigments have gained attention as eco-friendly and versatile materials for green nanotechnology because of their varied chemical structures, inherent redox properties, and strong metal ion-binding capabilities. These pigments, such as polyketides, azaphilones, melanins, and carotenoids, can function simultaneously as reducing, capping, and surface-functionalizing agents, facilitating the environmentally friendly production of metallic nanoparticles without the use of harmful chemicals. This review provides a critical overview of recent progress in the production, extraction, and application of fungal pigments for nanoparticle synthesis, focusing on the mechanistic roles of pigment functional groups in metal ion reduction, nanoparticle nucleation, growth, and stabilization. The impact of pigment chemistry and reaction conditions on the nanoparticle size, shape, crystallinity, and colloidal stability was thoroughly examined. Additionally, this review highlights the emerging biomedical, environmental, and industrial applications of pigment-mediated nanoparticles, emphasizing their biocompatibility and functional adaptability. Key challenges, such as variability in pigment yield and composition, limited mechanistic validation, lack of standardized synthesis protocols, and insufficient toxicity assessment, are critically analyzed in this review. Finally, future directions are outlined, emphasizing the importance of process optimization, omics-guided pigment discovery, and comprehensive safety evaluations as crucial steps toward the scalable and reliable use of fungal pigment-mediated nanoparticle synthesis in sustainable nanotechnology. Full article

Previous studies have considered the iridescent feathers of the peafowl as a classic example of structural coloration. The structural color is primarily attributed to a two-dimensional (2D) photonic crystal structure composed of melanin rods and air channels embedded in a keratin matrix. While previous optical models have successfully explained spectral tuning via geometric parameters such as lattice constants and cortex thickness, the potential contribution of auxiliary pigments to these complex hues has been largely overlooked. In this study, we combined high-sensitivity UPLC-MS and transcriptome analysis to elucidate the biochemical and genetic mechanisms underlying peafowl coloration. We identified trace amounts of the Xanthophyll lutein (one of the carotenoids) in iridescent train feathers, challenging the purely structural paradigm. Transcriptome analysis revealed significant differences in the expression of the melanin-related gene ASIP between iridescent and non-iridescent feather follicles. Furthermore, we observed significant expression differences in the carotenoid deposition-related gene GSTA2, correlating with the presence of lutein in iridescent regions. We conclude that while melanin provides the structural foundation for iridescence, lutein acts as an indispensable conditional modulator. The coordinated differential expression of melanin synthesis (ASIP) and carotenoid deposition (GSTA2) genes constitutes the genetic basis for the vibrant iridescent coloration of peafowl feathers. Full article

Carotenoids are increasingly studied for their robust antioxidant capacity, anti-inflammatory potential, protective vision and validated contribution to human health. Carotenoids are mainly obtained through chemical synthesis and plant extraction, which results in relatively high costs for producing carotenoids. However, microalgae represent a sustainable and high-yield platform for natural carotenoid production, with advantages including rapid growth, high pigment accumulation, and broad environmental adaptability. This review summarizes recent biotechnological advances in enhancing carotenoid production, with a focus on metabolic engineering, environmental regulation, and cultivation strategies. CRISPR/Cas9 enables precision metabolic pathway engineering, while environmental factors like light, nutrients, and stress significantly influence yield. Different cultivation strategies allow carotenoids to fulfill commercial or research needs. The two-stage strategy achieves rapid biomass increase during the growth stage, then shifts to accumulate carotenoids. This regulatory mode significantly reduces cell death by continuous stress, providing high productivity and stability in large-scale production. Carotenoids participate in many innovative applications across various fields, including treatments in medicine, skin protection in cosmetics, protein stabilization in foods, enhancing animals’ survival and so on. Future research will integrate bioprocess optimization, precision strain engineering, and adaptive environmental strategies to scale high-value microalgal carotenoid production as a commercially and environmentally viable solution. Full article

Abiotic stresses disrupt redox homeostasis and reduce crop productivity. Antioxidant networks support resilience by limiting excess reactive oxygen species (ROS) and maintaining redox signalling for stress perception, gene expression, and metabolic reprogramming. We summarize advances (2000–2025) in ROS generation, detoxification mechanisms, and signalling across organelles, including chloroplasts, mitochondria, peroxisomes, and the apoplast. This includes compartmentalized enzymes—superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), glutathione peroxidase (GPX), and glutathione reductase (GR)—as well as the peroxiredoxin–thioredoxin system and non-enzymatic buffers like ascorbate, glutathione, tocopherols, carotenoids, and flavonoids. We uniquely synthesize these findings in a compartment-resolved “redox rheostat” model, linking ROS concentration–time windows (signaling vs. damage) to antioxidant network design (kinetic tiers, compartmentation, and trade-offs) and identifying intervention points for breeding, genome editing, and field-scale priming. We emphasize constraints, such as NADPH supply and antioxidant recycling capacity, that lead to context-dependent outcomes. We evaluate omics, transgenic strategies, genome editing (CRISPR and Cas systems), exogenous applications, and plant–microbe associations. This synthesis clarifies how antioxidant systems protect photosynthetic and respiratory machinery while supporting signalling, thus outlining routes to climate-resilient, yield-stable crops across varied environments and stresses. Full article

The increasing global population and progressive soil salinization threaten future food security and sustainable agriculture. Halophytes, as salt-tolerant plants adapted to saline environments, represent promising alternative crops and valuable sources of nutrients and bioactive compounds. This review presents a structured synthesis of selected halophytes, with emphasis on wild species of ethnobotanical relevance. The nutritional value of halophytes is discussed with respect to proteins, polysaccharides, lipids, minerals, and vitamins, together with their diverse profiles regarding bioactive compounds, such as polyphenols, terpenes and terpenoids (including carotenoids), alkaloids, saponins and chlorophylls. In addition, the biological activities and available clinical evidence of halophyte-derived compounds are summarized, with Lobularia maritima presented as a representative example. By organizing nutritional and phytochemical data according to compound classes, this review provides a perspective largely absent from previous studies and highlights the potential of halophytes as innovative ingredients for the food and pharmaceutical industries, as well as outlining future research challenges and prospects. Full article

The fruits of Solanum lycopersicum L. cultivar “Microtom” are a powerful source of antioxidants. We investigated whether two light-quality regimes, i.e., fluorescent white (FL) and red-blue (RB), influenced the antioxidant composition in such fruits, and assessed the potential radioprotective properties of their extracts on normal human cells exposed to clinical photons as used in cancer radiotherapy (RT). Increasing normal-tissue tolerance to radiation is critical for reducing the risk of RT-associated sequelae. Biochemical characterization showed that RB enhanced the content of antioxidant phytochemicals (i.e., polyphenols, flavonoids, total carotenoids, lycopene), while FL promoted ascorbic acid synthesis. Initially tested at 200 µg/mL, RB-derived extracts decreased radiation-induced DNA damage as measured by the cytokinesis-block micronucleus (CBMN) assay in epidermal HaCaT cells. Both RB and FL regimes were subsequently studied in MCF-10A breast cancer (BC) cells, a model of normal-tissue radioresponse in BC RT, using extracts at 100 and 200 µg/mL and also evaluating oxidative stress by a ROS detection assay. Both FL and RB afforded radioprotection. However, RB suppressed radiation-induced MN formation and oxidative stress to a greater extent compared to FL. Therefore, modulation of light-quality regimes represents an innovative approach for developing radionutraceuticals with potential benefits for RT patients. Full article

This study evaluated protein hydrolysates from fish collagen (Col) and sheep keratin (Ker) as potential biostimulants in the hydro-priming of coriander (Coriandrum sativum L.) seeds. Seeds treated with low, non-nutritional doses of Col (0.5%) and Ker (1%) were compared with non-primed (C) and water-primed (H) controls under optimal conditions and after high-temperature stress (35 °C, 9 days). After stress removal, H-Col and H-Ker seeds achieved ~90% germination, whereas H and C reached 78% and 60%, respectively, confirming improved seed quality and post-stress recovery. Seedlings from Col- and Ker-treated seeds showed enhanced growth, higher biomass, and increased chlorophyll and precursor content. High-temperature stress also acted as a priming factor, modifying elemental profiles and stimulating carotenoid antioxidant synthesis. ATR–FTIR analyses indicated changes in cell wall composition and protein structure, particularly in the H-Ker variant. The results demonstrate that collagen and keratin hydrolysates, as industrial by-products, possess strong phytobiostimulatory potential and can be applied in sustainable strategies to improve seed quality and plant stress resilience. Full article