Enhancing astaxanthin biosynthesis and pathway expansion towards glycosylated C40 carotenoids by Corynebacterium glutamicum.

Astaxanthin, a versatile C40 carotenoid prized for its applications in food, cosmetics, and health, is a bright red pigment with powerful antioxidant properties. To enhance astaxanthin production in Corynebacterium glutamicum, we employed rational pathway engineering strategies, focused on improving precursor availability and optimizing terminal oxy-functionalized C40 carotenoid biosynthesis. Our efforts resulted in an increased astaxanthin precursor supply with 1.5-fold higher ß-carotene production with strain BETA6 (18 mg g-1 CDW). Further advancements in astaxanthin production were made by fine-tuning the expression of the ß-carotene hydroxylase gene crtZ and ß-carotene ketolase gene crtW, yielding a nearly fivefold increase in astaxanthin (strain ASTA**), with astaxanthin constituting 72% of total carotenoids. ASTA** was successfully transferred to a 2 L fed-batch fermentation with an enhanced titer of 103 mg L-1 astaxanthin with a volumetric productivity of 1.5 mg L-1 h-1. Based on this strain a pathway expansion was achieved towards glycosylated C40 carotenoids under heterologous expression of the glycosyltransferase gene crtX. To the best of our knowledge, this is the first time astaxanthin-ß-D-diglucoside was produced with C. glutamicum achieving high titers of microbial C40 glucosides of 39 mg L-1. This study showcases the potential of pathway engineering to unlock novel C40 carotenoid variants for diverse industrial applications.

Astaxanthin from microalgae: A review on structure, biosynthesis, production strategies and application.

Astaxanthin is a red-colored secondary metabolite with excellent antioxidant properties, typically finds application as foods, feed, cosmetics, nutraceuticals, and medications. Astaxanthin is usually produced synthetically using chemicals and costs less as compared to the natural astaxanthin obtained from fish, shrimps, and microorganisms. Over the decades, astaxanthin has been naturally synthesized from Haematococcus pluvialis in commercial scales and remains exceptional, attributed to its higher bioactive properties as compared to synthetic astaxanthin. However, the production cost of algal astaxanthin is still high due to several bottlenecks prevailing in the upstream and downstream processes. To that end, the present study intends to review the recent trends and advancements in astaxanthin production from microalgae. The structure of astaxanthin, sources, production strategies of microalgal astaxanthin, and factors influencing the synthesis of microalgal astaxanthin were discussed while detailing the pathway involved in astaxanthin biosynthesis. The study also discusses the relevant downstream process used in commercial scales and details the applications of astaxanthin in various health related issues.

Fluorescence quenching in aggregates of fucoxanthin-chlorophyll protein complexes: Interplay of fluorescing and dark states.

Diatoms, a major group of algae, account for about a quarter of the global primary production on Earth. These photosynthetic organisms face significant challenges due to light intensity variations in their underwater habitat. To avoid photodamage, they have developed very efficient non-photochemical quenching (NPQ) mechanisms. These mechanisms originate in their light-harvesting antenna - the fucoxanthin-chlorophyll protein (FCP) complexes. Spectroscopic studies of NPQ in vivo are often hindered by strongly overlapping signals from the photosystems and their antennae. Fortunately, in vitro FCP aggregates constitute a useful model system to study fluorescence (FL) quenching in diatoms. In this work, we present streak-camera FL measurements on FCPa and FCPb complexes, isolated from a centric diatom Cyclotella meneghiniana, and their aggregates. We find that spectra of non-aggregated FCP are dominated by a single fluorescing species, but the FL spectra of FCP aggregates additionally contain contributions from a redshifted emissive state. We relate this red state to a charge transfer state between chlorophyll c and chlorophyll a molecules. The FL quenching, on the other hand, is due to an additional dark state that involves incoherent energy transfer to the fucoxanthin carotenoids. Overall, the global picture of energy transfer and quenching in FCP aggregates is very similar to that of major light-harvesting complexes in higher plants (LHCII), but microscopic details between FCPs and LHCIIs differ significantly.

Mediator subunit MED8 interacts with heat shock transcription factor HSF3 to promote fucoxanthin synthesis in the diatom Phaeodactylum tricornutum.

Fucoxanthin, a natural carotenoid that has substantial pharmaceutical value due to its anticancer, antioxidant, antiobesity, and antidiabetic properties, is biosynthesized from glyceraldehyde-3-phosphate (G3P) via a series of enzymatic reactions. However, our understanding of the transcriptional mechanisms involved in fucoxanthin biosynthesis remains limited. Using reverse genetics, the med8 mutant was identified based on its phenotype of reduced fucoxanthin content, and the biological functions of MED8 in fucoxanthin synthesis were characterized using approaches such as gene expression, protein subcellular localization, protein-protein interaction and chromatin immunoprecipitation assay. Gene-editing mutants of MED8 exhibited decreased fucoxanthin content as well as reduced expression levels of six key genes involved in fucoxanthin synthesis, namely DXS, PSY1, ZDS-like, CRTISO5, ZEP1, and ZEP3, when compared to the wild-type (WT) strain. Furthermore, we showed that MED8 interacts with HSF3, and genetic analysis revealed their shared involvement in the genetic pathway governing fucoxanthin synthesis. Additionally, HSF3 was required for MED8 association with the promoters of the six fucoxanthin synthesis genes. In conclusion, MED8 and HSF3 are involved in fucoxanthin synthesis by modulating the expression of the fucoxanthin synthesis genes. Our results increase the understanding of the molecular regulation mechanisms underlying fucoxanthin synthesis in the diatom P. tricornutum.

Exogenous arginine promotes the coproduction of biomass and astaxanthin under high-light conditions in Haematococcus pluvialis.

The economical way of Haematococcus pluvialis farming is to simultaneously achieve biomass, astaxanthin and lipid using less expensive chemicals. This paper explores the role of exogenous arginine in promoting growth and astaxanthin accumulation under stressful conditions. The application of arginine exerts a synergic effect on biomass, astaxanthin and lipid by improving carbon utilization, activating the arginine pathway and regulating carotenoid and lipid-related genes. Genes related to arginine catabolism, such as ADC, OCT, ASS1, NOS, and OAT, were up-regulated at both the cultivation and astaxanthin induction stages, signifying their importance in both growth and astaxanthin synthesis. Furthermore, transcriptome analysis revealed that arginine up-regulated transcription levels of genes involved carbon fixing, lipid biosynthesis, pyruvate metabolism, carotenoid, tricarboxylic acid cycle, and arginine and proline metabolism. The results provide a significant mechanism and applicability of using exogenous arginine and high light to stimulate bioproducts from Haematococcus pluvialis.

Advancement of Carotenogenesis of Astaxanthin from Haematococcus pluvialis: Recent Insight and Way Forward.

The demand for astaxanthin has been increasing for many health applications ranging from pharmaceuticals, food, cosmetics, and aquaculture due to its bioactive properties. Haematococcus pluvialis is widely recognized as the microalgae species with the highest natural accumulation of astaxanthin, which has made it a valuable source for industrial production. Astaxanthin produced by other sources such as chemical synthesis or fermentation are often produced in the cis configuration, which has been shown to have lower bioactivity. Additionally, some sources of astaxanthin, such as shrimp, may denature or degrade when exposed to high temperatures, which can result in a loss of bioactivity. Producing natural astaxanthin through the cultivation of H. pluvialis is presently a demanding and time-consuming task, which incurs high expenses and restricts the cost-effective industrial production of this valuable substance. The production of astaxanthin occurs through two distinct pathways, namely the cytosolic mevalonate pathway and the chloroplast methylerythritol phosphate (MEP) pathway. The latest advancements in enhancing product quality and extracting techniques at a reasonable cost are emphasized in this review. The comparative of specific extraction processes of H. pluvialis biological astaxanthin production that may be applied to large-scale industries were assessed. The article covers a contemporary approach to optimizing microalgae culture for increased astaxanthin content, as well as obtaining preliminary data on the sustainability of astaxanthin production and astaxanthin marketing information.

Unraveling the underlying mechanism of interactions between astaxanthin geometrical isomers and bovine serum albumin.

The health benefits of astaxanthin (AST) are related to its geometric isomers. Generally, functional activity is realized by the interactions between active substances and transporters. Hereto, bovine serum albumin (BSA), as a model-binding protein and transporter, is able to recognize and transport isomers of active substances through binding with them. However, differences in the binding mechanism of isomers to BSA may affect the functional activities of isomers through the "binding-transport-activity" chain reaction. Thus, this study sought to elucidate the interactions between AST geometrical isomers and BSA using multi-spectroscopy, surface plasmon resonance and molecular docking. The results showed that Z-AST displayed more interacting amino acid residues and lower thermodynamic parameters than all-E-AST. Meanwhile, the order of binding affinity to BSA was 13Z-AST (1.56 × 10-7 M) > 9Z-AST (2.70 × 10-7 M) > all-E-AST (4.01 × 10-7 M), indicating that Z-AST possessed stronger binding ability to BSA. Moreover, AST isomers were located at the junction between subdomains ⅡA and ⅢA of BSA, and showed the same interaction forces (hydrogen bond and van der Waals force) as well as kinetic processes (slow combination, slow dissociation). These interaction parameters provide valuable insights into their pharmacokinetics in vivo, and it was of great significance to explain the potential differences among AST isomers in functional activities.

Lipid composition and properties affect protein-mediated carotenoid uptake efficiency from membranes.

Carotenoids are pigments of diverse functions ranging from coloration over light-harvesting to photoprotection. Yet, the number of carotenoid-binding proteins, which mobilize these pigments in physiological media, is limited, and the mechanisms of carotenoid mobilization are still not well understood. The same applies for the determinants of carotenoid uptake from membranes into carotenoproteins, especially regarding the dependence on the chemical properties of membrane lipids. Here, we investigate xanthophyll uptake capacity and kinetics of a paradigmatic carotenoid-binding protein, the homolog of the Orange Carotenoid Protein's C-terminal domain from Anabaena sp. PCC 7120 (AnaCTDH), using liposomes formed from defined lipid species and loaded with canthaxanthin (CAN) and echinenone (ECN), respectively. Phospholipids with different chain length and degree of saturation were investigated. The composition of carotenoid-loaded liposomes directly affected the incorporation yield and storage ratio of CAN and ECN as well as the rate of carotenoid uptake by AnaCTDH. Generally, saturated PC lipids were identified as unsuitable, and a high phase transition temperature of the lipids negatively affected the carotenoid incorporation and storage yield. For efficient carotenoid transfer, the velocity increases with increasing chain length or membrane thickness. An average transfer yield of 93 % and 43 % were obtained for the formation of AnaCTDH(CAN) and AnaCTDH(ECN) holoproteins, respectively. In summary, the most suitable lipids for the formation of AnaCTDH(CAN/ECN) holoproteins by carotenoid transfer from artificial liposomes are phosphatidylcholine (18:1) and phosphatidylglycerol (14:0). Thus, these two lipids provide the best conditions for further investigation of lipid-protein interaction and the carotenoid uptake process.

Kinetics of the xanthophyll cycle and its role in photoprotective memory and response.

Efficiently balancing photochemistry and photoprotection is crucial for survival and productivity of photosynthetic organisms in the rapidly fluctuating light levels found in natural environments. The ability to respond quickly to sudden changes in light level is clearly advantageous. In the alga Nannochloropsis oceanica we observed an ability to respond rapidly to sudden increases in light level which occur soon after a previous high-light exposure. This ability implies a kind of memory. In this work, we explore the xanthophyll cycle in N. oceanica as a short-term photoprotective memory system. By combining snapshot fluorescence lifetime measurements with a biochemistry-based quantitative model, we show that short-term memory arises from the xanthophyll cycle. In addition, the model enables us to characterize the relative quenching abilities of the three xanthophyll cycle components. Given the ubiquity of the xanthophyll cycle in photosynthetic organisms the model described here will be of utility in improving our understanding of vascular plant and algal photoprotection with important implications for crop productivity.

The impact of long-term acclimation to different growth light intensities on the regulation of zeaxanthin epoxidase in different plant species.

Proper short- and long-term acclimation to different growth light intensities is essential for the survival and competitiveness of plants in the field. High light exposure is known to induce the down-regulation and photoinhibition of photosystem II (PSII) activity to reduce photo-oxidative stress. The xanthophyll zeaxanthin (Zx) serves central photoprotective functions in these processes. We have shown in recent work with different plant species (Arabidopsis, tobacco, spinach and pea) that photoinhibition of PSII and degradation of the PSII reaction center protein D1 is accompanied by the inactivation and degradation of zeaxanthin epoxidase (ZEP), which catalyzes the reconversion of Zx to violaxanthin. Different high light sensitivity of the above-mentioned species correlated with differential down-regulation of both PSII and ZEP activity. Applying light and electron microscopy, chlorophyll fluorescence, and protein and pigment analyses, we investigated the acclimation properties of these species to different growth light intensities with respect to the ability to adjust their photoprotective strategies. We show that the species differ in phenotypic plasticity in response to short- and long-term high light conditions at different morphological and physiological levels. However, the close co-regulation of PSII and ZEP activity remains a common feature in all species and under all conditions. This work supports species-specific acclimation strategies and properties in response to high light stress and underlines the central role of the xanthophyll Zx in photoprotection.

Enhancement of astaxanthin production, recovery, and bio-accessibility in Haematococcus pluvialis through taurine-mediated inhibition of secondary cell wall formation under high light conditions.

This study explored the use of taurine in enhancing the production and bio-accessibility of astaxanthin in Haematococcus pluvialis, which typically forms a secondary cell wall hindering astaxanthin extraction. The biomass of taurine-treated group significantly increased by 18%, and astaxanthin yield surged by 34% in comparison to the control group. Without cell disruption, astaxanthin recovery from thin-walled cells in the taurine-treated group, using dimethyl sulfoxide and ethanol as extraction reagents, was 97% and 75%, respectively, which were 30-fold higher than those of thick-walled cells in the control group. Additionally, the cell fragmentation rate increased by 86% in taurine-treated group relative to the control group. Comparative transcriptome analysis identified taurine-induced upregulation of genes involved in the astaxanthin biosynthesis pathway and downregulation of those associated with secondary cell wall synthesis. This study thus offers an innovative taurine-based strategy to enhance astaxanthin production and bio-accessibility while shedding light on the mechanisms driving this process.

A novel drying film culture method applying a natural phenomenon: Increased carotenoid production by Haematococcus sp.

Low productivity and high cost remain major bottlenecks for the large-scale production of Haematococcus sp. This study explored biomass production and carotenoid accumulation in Haematococcus sp. (KCTC 12348BP) using drying film culture. The broth-cultured strain (3.2 × 106 cells/mL, 0.83 ± 0.02 mg/mL for a 21 d culture) was cultured under various conditions (different inoculum volumes and mist feeding intervals) in waterless agar plates at 28 ± 0.5 °C, under fluorescent light (12 h light-dark cycle) for 1 month. The maximum biomass obtained was 17.60 ± 0.72 g/m2, while the maximum astaxanthin concentration was 8.23 ± 1.13 mg/g in the culture using 1 mL inoculum and 3 d feeding interval. Drought stress in drying film culture effectively induced the accumulation of carotenoids from ß-carotene, facilitating the production of canthaxanthin via the astaxanthin biosynthesis pathway. This cost-effective culture system can increase the biomass and carotenoid pigment production in Haematococcus sp.

Transcriptomics analysis and fed-batch regulation of high astaxanthin-producing Phaffia rhodozyma/Xanthophyllomyces dendrorhous obtained through adaptive laboratory evolution.

Astaxanthin has high utilization value in functional food because of its strong antioxidant capacity. However, the astaxanthin content of Phaffia rhodozyma is relatively low. Adaptive laboratory evolution is an excellent method to obtain high-yield strains. TiO2 is a good inducer of oxidative stress. In this study, different concentrations of TiO2 were used to domesticate P. rhodozyma, and at a concentration of 1000 mg/L of TiO2 for 105 days, the optimal strain JMU-ALE105 for astaxanthin production was obtained. After fermentation, the astaxanthin content reached 6.50 mg/g, which was 41.61% higher than that of the original strain. The ALE105 strain was fermented by batch and fed-batch, and the astaxanthin content reached 6.81 mg/g. Transcriptomics analysis showed that the astaxanthin synthesis pathway, and fatty acid, pyruvate, and nitrogen metabolism pathway of the ALE105 strain were significantly upregulated. Based on the nitrogen metabolism pathway, the nitrogen source was adjusted by ammonium sulphate fed-batch fermentation, which increased the astaxanthin content, reaching 8.36 mg/g. This study provides a technical basis and theoretical research for promoting industrialization of astaxanthin production of P. rhodozyma. ONE-SENTENCE SUMMARY: A high-yield astaxanthin strain (ALE105) was obtained through TiO2 domestication, and its metabolic mechanism was analysed by transcriptomics, which combined with nitrogen source regulation to further improve astaxanthin yield.

Lutein and zeaxanthin - radio- and chemoprotective properties. Mechanism and possible use.

Lutein and zeaxanthin are naturally occurring xanthophylls, mainly present in green, leafy vegetables and egg's yolk. Their presence is connected with blue spectrum light absorbance, including UV. This property, and fact, that these xanthophylls are accumulated by human eye's macula, leads to eye's protective functions of them including protection from age-related macular degeneration (AMD). Also, antioxidative features of lutein and zeaxanthin are boosting overall health of human body. Numerous studies proves anti-inflammatory and protective attributes of these compounds, based on many, different mechanisms. One of them is regulating redox potential in cells, and impact on expression of linked genes. In preventing of eye diseases, an important gene that is regulated by lutein and zeaxanthin is the Nrf2 gene, whose increased activity leads to optimizing the cellular response to reactive oxygen species (ROS) and preventing related diseases. Other research confirms antiproliferative properties of mentioned compounds in case of certain human cancer cell lines. There are e.g.: HepG2 (hepatitis cancer), MCF-7 (breast cancer), which treated in vitro with lutein solution showed reduction of cell growth. Lutein alone, during in vivo studies conducted on mice, exhibited also radioprotective properties, positively affecting the vitality of animals. Lutein provides also increasing of tolerance to UV radiation, reducing inflammatory processes in the skin and preventing oncogenesis. Low intake of lutein and zeaxanthin, associated with "western diet", rich in simple carbohydrates and processed food, common in developed countries, including Poland, is linked with diabetes and obesity incidence. Assuming, lutein and zeaxanthin significantly affect the well-being of the human body, and their appropriate amount in diet can help reduce risk of many diseases. For supplementation, the optimized dosage of these xanthophylls includes doses of 10 mg for lutein and 2 mg for zeaxanthin, and it is recommended to consume along with fats or meals rich in fats.

How Do Xanthophylls Protect Lipid Membranes from Oxidative Damage?

Here, we address the problem of the antioxidant activity of carotenoids in biomembranes. The activity of lutein and zeaxanthin in the quenching of singlet oxygen generated by photosensitization was monitored in lipid vesicles using a singlet oxygen-sensitive fluorescent probe and with the application of fluorescence lifetime imaging microscopy. The antioxidant activity of xanthophylls was interpreted on the basis of electron paramagnetic resonance oximetry results showing that xanthophylls constitute a barrier to the penetration of molecular oxygen into lipid membranes: to a greater extent in the 13-cis configuration than in all-trans. These results are discussed in relation to the trans-cis photoisomerization of xanthophylls observed in the human retina. It can be concluded that photoisomerization of xanthophylls is a regulatory mechanism that is important for both the modulation of light filtration through the macula and photoprotection by quenching singlet oxygen and creating a barrier to oxygen permeation to membranes.

Fucoxanthin Attenuates Inflammation via Interferon Regulatory Factor 3 (IRF3) to Improve Sepsis.

Suppression of excessive inflammatory responses improves the survival of patients with sepsis. We previously illustrated the anti-inflammatory effects of fucoxanthin (FX), a natural carotenoid isolated from brown algae; nevertheless, the underlying mechanism remains unknown. In this study, we examine the mechanism of the action of FX by targeting interferon regulatory factor 3 (IRF3) to inhibit inflammatory response. We observed that FX regulated innate immunity by inhibiting IRF3 phosphorylation in vitro. The in silico approach demonstrated a good binding mode between FX and IRF3. To examine the in vivo effects of FX, a mouse model of sepsis induced by cecal ligation and puncture (CLP) was created using both wild-type (WT) and Irf3-/- mice. FX significantly reduced pro-inflammatory cytokine levels and reactive oxygen species production, changed the circulating immune cell composition, and increased the survival rate of the CLP-induced sepsis model. Overall, FX ameliorated sepsis by targeting IRF3 activation, providing novel insights into the therapeutic potential and molecular mechanism of action of FX in the treatment of sepsis and suggesting that it may be used clinically to improve the survival rate in mice undergoing sepsis.

The Amount of Zeaxanthin Epoxidase But Not the Amount of Violaxanthin De-Epoxidase Is a Critical Determinant of Zeaxanthin Accumulation in Arabidopsis thaliana and Nicotiana tabacum.

The generation of violaxanthin (Vx) de-epoxidase (VDE), photosystem II subunit S (PsbS) and zeaxanthin (Zx) epoxidase (ZEP) (VPZ) lines, which simultaneously overexpress VDE, PsbS and ZEP, has been successfully used to accelerate the kinetics of the induction and relaxation of non-photochemical quenching (NPQ). Here, we studied the impact of the overexpression of VDE and ZEP on the conversion of the xanthophyll cycle pigments in VPZ lines of Arabidopsis thaliana and Nicotiana tabacum. The protein amount of both VDE and ZEP was determined to be increased to about 3- to 5-fold levels of wild-type (WT) plants for both species. Compared to WT plants, the conversion of Vx to Zx, and hence VDE activity, was only marginally accelerated in VPZ lines, whereas the conversion of Zx to Vx, and thus ZEP activity, was strongly increased in VPZ lines. This indicates that the amount of ZEP but not the amount of VDE is a critical determinant of the equilibrium of the de-epoxidation state of xanthophyll cycle pigments under saturating light conditions. Comparing the two steps of epoxidation, particularly the second step (antheraxanthin to Vx) was found to be accelerated in VPZ lines, implying that the intermediate Ax is released into the membrane during epoxidation by ZEP.

Metabolic engineering of Escherichia coli for high-level production of violaxanthin.

BACKGROUND: Xanthophylls are a large class of carotenoids that are found in a variety of organisms and play particularly important roles in the light-harvesting and photoprotection processes of plants and algae. Violaxanthin is an important plant-derived xanthophyll with wide potential applications in medicines, foods, and cosmetics because of its antioxidant activity and bright yellow color. To date, however, violaxanthins have not been produced using metabolically engineered microbes on a commercial scale. Metabolic engineering for microbial production of violaxanthin is hindered by inefficient synthesis pathway in the heterologous host. We systematically optimized the carotenoid chassis and improved the functional expression of key enzymes of violaxanthin biosynthesis in Escherichia coli. RESULTS: Co-overexpression of crtY (encoding lycopene ß-cyclase), crtZ (encoding ß-carotene 3-hydroxylase), and ZEP (encoding zeaxanthin epoxidase) had a notable impact on their functions, resulting in the accumulation of intermediate products, specifically lycopene and ß-carotene. A chassis strain that did not accumulate the intermediate was optimized by several approaches. A promoter library was used to optimize the expression of crtY and crtZ. The resulting strain DZ12 produced zeaxanthin without intermediates. The expression of ZEP was further systematically optimized by using DZ12 as the chassis host. By using a low copy number plasmid and a modified dithiol/disulfide system, and by co-expressing a full electron transport chain, we generated a strain producing violaxanthin at about 25.28 ± 3.94 mg/g dry cell weight with decreased byproduct accumulation. CONCLUSION: We developed an efficient metabolically engineered Escherichia coli strain capable of producing a large amount of violaxanthin. This is the first report of a metabolically engineered microbial platform that could be used for the commercial production of violaxanthin.

Astaxanthin protects oocyte maturation against cypermethrin-induced defects in pigs.

Cypermethrin (CYP), a pyrethroid insecticide, exerts the detrimental effect on the reproductive system, while astaxanthin (AST), a xanthophyll carotenoid, possesses the powerful antioxidant property and can protect oocyte maturation. However, the toxicity of CYP and the protective role of AST against CYP during oocyte maturation remain unclear. Here, porcine oocytes were applied to investigate the potential effects and underlying mechanisms of CYP and AST during oocyte maturation. This work demonstrated that CYP significantly decreased oocyte maturation rate and subsequent embryo development in a dose-dependent manner (P < 0.05). And, CYP obviously induced the overproduction of reactive oxygen species and the reduction of glutathione content by downregulating the expression of redox genes in oocytes (P < 0.05). Moreover, CYP significantly caused oocyte DNA damage and disturbed the function of endoplasmic reticulum by altering the transcription of DNA damage repair and endoplasmic reticulum stress related genes (P < 0.05). Whereas CYP-exposed oocytes were treated with AST, these defects caused by CYP were significantly ameliorated (P < 0.05). In conclusion, this study demonstrated that CYP exerted the toxic effect on porcine oocytes, while AST effectively alleviated CYP-induced defects. This work provides a potential strategy to prevent pesticide toxicity and protect oocyte maturation in mammalian reproduction.

Fucoxanthin levels in maternal serum at birth and eczema risk in offspring in early childhood: A birth cohort study.

BACKGROUND: Fucoxanthin, a marine xanthophyll carotenoid, has been shown to exert beneficial health effects. Cell-based and animal-based experimental studies have shown that fucoxanthin has the potential to mitigate eczema symptoms. Hence, we sought to assess whether fucoxanthinol 3-arachidate, a fucoxanthin metabolite, measured in maternal serum at birth is associated with eczema development during early childhood. METHODS: Data from the 1989/1990 Isle of Wight birth cohort were analyzed. We focused on data obtained from the 1, 2, and 4 years follow-ups. Fucoxanthinol 3-arachidate was measured in maternal serum at the child's birth as abundance relative to the reference lipids. Eczema was ascertained according to parent-reported clinical history and characteristic morphology and distribution. Log-binomial regression models were used to estimate adjusted risk ratios (aRR) and their 95% confidence intervals (CI). RESULTS: A total of 592 subjects (49.2% males and 50.8% females) were included in the current analysis. Associations between fucoxanthinol 3-arachidate levels and eczema risk during the first 4 years of life (longitudinal analysis) were evaluated using four modeling approaches, which showed higher fucoxanthinol 3-arachidate levels were associated with reduced eczema risk: (i) aRRper 10 unit increase = 0.88, 95% CI: 0.76-1.03; (ii) aRR>0 vs. =0 = 0.67, 0.45-0.99; (iii) aRR≥2.3 vs. <2.3 = 0.66, 0.44-0.98; and (iv) aRRtertile 3 vs. tertile 1 = 0.65, 0.42-0.99. CONCLUSION: Our findings suggest that increased fucoxanthinol 3-arachidate levels measured in maternal serum at the child's birth is associated with reduced eczema risk during the first 4 years of the offspring life.