Mechanism of Different Stereoisomeric Astaxanthin in Resistance to Oxidative Stress inCaenorhabditis elegans

Phytoene and Phytoene-Rich Microalgae Extracts Extend Lifespan in C. elegans and Protect against Amyloid-β Toxicity in an Alzheimer's Disease Model

Phytoene is a colourless carotenoid widely available from dietary sources and a precursor for the synthesis of other carotenoids. Although present at high concentrations across different tissues, phytoene is largely viewed as not having physiological activity. Here, we utilize the model organism C. elegans to show that phytoene is bioactive and has anti-ageing properties. Supplementation with phytoene protects against oxidative damage and amyloid-β42 proteotoxicity (a major pathology of Alzheimer's disease), and extends lifespan. We also examine extracts from two microalgae, Chlorella sorokiniana and Dunaliella bardawil. We show that the extracts contain high levels of phytoene, and find that these phytoene-rich extracts have protective effects similar to pure phytoene. Our findings show that phytoene is a bioactive molecule with positive effects on ageing and longevity. Our work also suggests that phytoene-rich microalgae extracts can utilized to produce foods or supplements that promote healthy ageing and prevent the development of chronic age-related diseases.

Optimization of bacterioruberin production from Halorubrum ruber and assessment of its antioxidant potential

Haloarchaea produce bacterioruberin, a major C50 carotenoid with antioxidant properties that allow for its potential application in the food, cosmetic, and pharmaceutical industries. This study aimed to optimize culture conditions for total carotenoid, predominantly comprising bacterioruberin, production using Halorubrum ruber MBLA0099. A one-factor-at-a-time and statistically-based experimental design were applied to optimize the culture conditions. Culture in the optimized medium caused an increase in total carotenoid production from 0.496 to 1.966 mg L- 1 Maximal carotenoid productivity was achieved in a 7-L laboratory-scale fermentation and represented a 6.05-fold increase (0.492 mg L-1 d-1). The carotenoid extracts from strain MBLA0099 exhibited a 1.8-10.3-fold higher antioxidant activity in vitro, and allowed for a higher survival rate of Caenorhabditis elegans under oxidative stress conditions. These results demonstrated that Hrr. ruber MBLA0099 has significant potential as a haloarchaon for the commercial production of bacterioruberin.

Astaxanthin Isomers: A Comprehensive Review of Isomerization Methods and Analytic Techniques

The presence of multiple conjugated double bonds and chiral carbon atoms endows astaxanthin with geometric and optical isomers, and these isomers widely exist in biological sources, food processing, and in vivo absorption. However, there remains no systematic summary of astaxanthin isomers regarding isomerization methods and analytic techniques. To address this need, this Review focuses on a comprehensive analysis of Z-isomerization methods of astaxanthin, including solvent system, catalyst, and heat treatment. Comparatively, high-efficiency and health-friendly methods are more conducive to put into practical use, such as food-grade solvents and food-component catalysts. In addition, we outline the recent advances in analysis techniques of astaxanthin isomers, as well as the structural characteristics reflected by various methods (e.g., HPLC, NMR, FTIR, and RS). Furthermore, we summarized the related research on the safety evaluation of astaxanthin isomers. Finally, future trends and barriers in Z-transformation and analysis of astaxanthin isomers are also discussed.

High-Purity Bioactive Ingredient—3S,3′S-Astaxanthin: A New Preparation from Genetically Modified Kluyveromyces marxianus without Column Chromatography and Gel Filtration

A highly efficient methodology for bioactive ingredient 3S,3′S-astaxanthin (3S,3′S-AST) preparation from genetically modified yeast (Kluyveromyces marxianus) with a combination of enzyme-assisted extraction and salt-assisted liquid-liquid extraction (SALLE) was achieved. The highest yield of 3S,3′S-AST indicated that FoodPro® CBL for yeast cell walls hydrolysis could significantly enhance extraction and obtain, with the help of SALLE procedure, quantified 3S,3′S-AST over 99% in purity through cation chelation. In the oxygen radical antioxidant capacity (ORAC) assay, the antioxidant capacity of high-purity 3S,3′S-AST products were 18.3 times higher than that of the original raw material extract. This new combination preparation may replace previous methods and has the potential to be scaled up in the manufacture of high-purity 3S,3′S-AST from low-value bioresources of raw materials to high-value products in the food and/or drug industries with lower cost and simple equipment.

Astaxanthin as a King of Ketocarotenoids: Structure, Synthesis, Accumulation, Bioavailability and Antioxidant Properties

Astaxanthin (3,3-dihydroxy-β, β-carotene-4,4-dione) is a ketocarotenoid synthesized by Haematococcus pluvialis/lacustris, Chromochloris zofingiensis, Chlorococcum, Bracteacoccus aggregatus, Coelastrella rubescence, Phaffia rhodozyma, some bacteria (Paracoccus carotinifaciens), yeasts, and lobsters, among others However, it is majorly synthesized by Haematococcus lacustris alone (about 4%). The richness of natural astaxanthin over synthetic astaxanthin has drawn the attention of industrialists to cultivate and extract it via two stage cultivation process. However, the cultivation in photobioreactors is expensive, and converting it in soluble form so that it can be easily assimilated by our digestive system requires downstream processing techniques which are not cost-effective. This has made the cost of astaxanthin expensive, prompting pharmaceutical and nutraceutical companies to switch over to synthetic astaxanthin. This review discusses the chemical character of astaxanthin, more inexpensive cultivating techniques, and its bioavailability. Additionally, the antioxidant character of this microalgal product against many diseases is discussed, which can make this natural compound an excellent drug to minimize inflammation and its consequences.

Chemistry, Occurrence, Properties, Applications, and Encapsulation of Carotenoids-A Review

Carotenoids are natural lipophilic pigments and antioxidants that are present in many fruits and vegetables. The consumption of carotenoids is correlated with positive health effects and a decreased risk of several chronic diseases. Provitamin A carotenoids (β-carotene, α-carotene, γ-carotene, and β-cryptoxanthin) are essential for the development and maintenance of sight. β-carotene, α-carotene, zeaxanthin, β-cryptoxanthin, lutein, and lycopene have high antioxidant activity and promote free radical scavenging, which helps protect against chronic diseases. However, carotenoids are chemically unstable and prone to oxidation in the presence of light, heat, oxygen, acids, and metal ions. The use of carotenoids in the food industry is limited due to their poor solubility in water, bioavailability and quick release. Encapsulation techniques, such as microencapsulation, nanoencapsulation and supercritical encapsulation, are used to overcome these problems. The objective of this paper is to describe the characteristics and potential health benefits of carotenoids and advances in encapsulation techniques for protecting and enhancing their solubility or bioavailability.

Astaxanthin Induces Transcriptomic Responses Associated with Lifespan Extension in Caenorhabditis elegans

Astaxanthin is a marine xanthophyll carotenoid which effectively prevents intracellular oxidative stress and has beneficial effects against various human diseases. It has been shown that astaxanthin protects Caenorhabditis elegans (C. elegans) from oxidative damages and extends the lifespan of C. elegans possibly by modulating genes involved in insulin/insulin-like growth factor (IGF) signaling (IIS) and the oxidoreductase system, although the exact mechanisms remain elusive. In this study, RNA sequencing analyses were employed to identify the differentially expressed genes in C. elegans in response to astaxanthin treatment. A total of 190 mRNAs and 6 microRNAs (miRNAs) were significantly changed by astaxanthin treatment in C. elegans. Gene ontology (GO) term and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses indicated that the mRNAs and miRNAs significantly altered by astaxanthin mainly function in innate immunity, lipid metabolism and stress responses, a significant portion of which are related to lifespan regulation in C. elegans. The study revealed novel mRNA and miRNA targets of astaxanthin, providing new insights for understanding the anti-aging mechanisms and the biological function of astaxanthin.

Biological and neurological activities of astaxanthin (Review)

Astaxanthin is a lipid‑soluble carotenoid produced by various microorganisms and marine animals, including bacteria, yeast, fungi, microalgae, shrimps and lobsters. Astaxanthin has antioxidant, anti‑inflammatory and anti‑apoptotic properties. These characteristics suggest that astaxanthin has health benefits and protects against various diseases. Owing to its ability to cross the blood‑brain barrier, astaxanthin has received attention for its protective effects against neurological disorders, including Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis, cerebral ischemia/reperfusion, subarachnoid hemorrhage, traumatic brain injury, spinal cord injury, cognitive impairment and neuropathic pain. Previous studies on the neurological effects of astaxanthin are mostly based on animal models and cellular experiments. Thus, the biological effects of astaxanthin on humans and its underlying mechanisms are still not fully understood. The present review summarizes the neuroprotective effects of astaxanthin, explores its mechanisms of action and draws attention to its potential clinical implications as a therapeutic agent.

DFT-based Raman spectral study of astaxanthin geometrical isomers

Astaxanthin is a carotenoid widely used in food additives, nutritional product and medicines, which shows many physiological functions such as antioxidant, anti-inflammatory, anti-hypertensive and anti-diabetic activities. It has been recognized that astaxanthin has all-trans and nine cis isomers, and these geometrical isomers have very different biological activities. The process of selective enrichment, metabolism and isomerization of astaxanthin in animals remains to be studied. Therefore, identifying isomers and obtaining their structural parameters are important for understanding the active mechanism of different molecular isomers. Although the traditional methods such as high-performance liquid chromatography (HPLC) and nuclear magnetic resonance (NMR) spectroscopy can be used to distinguish these isomers, these methods generally require considerable testing time, cost, sample volume, and hardly be applied in vivo. In this work, Raman spectroscopy combined with density functional theory (DFT) calculation was introduced to study different geometrical isomers of astaxanthin. The theoretical and experimental Raman spectra are in agreement, and we have demonstrated that all the known ten geometrical isomers of astaxanthin can be readily distinguished using this spectroscopic approach. The astaxanthin molecular vibrational modes, geometric structures, energies of ten geometric isomers are systematically scrutinized. Moreover, a lot of structural and Raman problems unsolved previously have been solved by the DFT-based spectral analysis. Therefore, this work provides an effective way for identification of different astaxanthin geometrical isomers, and may have important significance for promoting the research of astaxanthin isomers on biological property mechanisms and related applications in food molecular science.

DFT and Raman study of all-trans astaxanthin optical isomers

Astaxanthin (AST) is a xanthophyll carotenoid widely distributed in aquatic animals, which has many physiological functions such as antioxidant, anti-inflammatory, anti-hypertensive and anti-diabetic activities. AST has three optical isomers, including a pair of enantiomers (3S,3'S and 3R,3'R) and a meso form (3R,3'S). Different optical isomers have differences in a variety of physiological functions. Traditionally, High Performance Liquid Chromatography (HPLC) has been used to distinguish these isomers. In this work, it was found that Raman spectroscopy can be employed to distinguish the three optical isomers. The intensities of two Raman bands at 1190 and 1215 cm^-1 of three isomers are different. Density Functional Theory (DFT) calculations are performed to analyze the spectral differences. The mainly occupied conformers of these three optical isomers are speculated and identified.

Dietary astaxanthin: an excellent carotenoid with multiple health benefits

Astaxanthin is a carotenoid widely found in marine organisms and microorganisms. With extensive use in nutraceuticals, cosmetics, and animal feed, astaxanthin will have the largest share in the global market for carotenoids in the near future. Owing to its unique molecular features, astaxanthin has excellent antioxidant activity and holds promise for use in biochemical studies. This review focuses on the observed health benefits of dietary astaxanthin, as well as its underlying bioactivity mechanisms. Recent studies have increased our understanding of the role of isomerization and esterification in the structure-function relationship of dietary astaxanthin. Gut microbiota may involve the fate of astaxanthin during digestion and absorption; thus, further knowledge is needed to establish accurate recommendations for dietary intake of both healthy and special populations. Associated with the regulation of redox balance and multiple biological mechanisms, astaxanthin is proposed to affect oxidative stress, inflammation, cell death, and lipid metabolism in humans, thus exerting benefits for skin condition, eye health, cardiovascular system, neurological function, exercise performance, and immune response. Additionally, preclinical trials predict its potential effects such as intestinal flora regulation and anti-diabetic activity. Therefore, astaxanthin is worthy of further investigation for boosting human health, and wide applications in the food industry.

Protective effects of astaxanthin on lipopolysaccharide-induced inflammation in bovine endometrial epithelial cells†

Astaxanthin (AST), a natural antioxidant carotenoid, has been shown to exert anti-inflammatory effects. However, to our knowledge, no study has specifically addressed the potential protective effects of AST against bovine endometritis. The purpose of this study was to examine whether treatment with AST could protect endometrial epithelial cells against lipopolysaccharide (LPS)-induced inflammatory injury. Treatment of bovine endometrial (BEND) epithelial cell line with AST reduced LPS-induced production of interleukin-6 and tumor necrosis factor-alpha, increased the cellular activity of superoxide dismutase and catalase, decreased the proportion of apoptotic cells, and promoted the production of insulin-like growth factor and epithelial growth factor. The effects of AST were mediated through the downregulation of B-cell lymphoma 2 (Bcl-2) associated X, apoptosis regulator (Bax), and cleaved caspase-3 and through the upregulation of Bcl-2. Moreover, AST significantly increased the expression of the tight junction proteins (TJP) claudin, cadherin-1, and TJP1, which play an essential role in the maintenance of host endometrial defense barrier against pathogen infection. Collectively, these results demonstrated that treatment with AST protected against oxidative stress, prevented cell apoptosis, promoted BEND cells viability, and increased the production of growth factors, in addition to activating the endometrial defense barrier. Therefore, AST is a promising therapeutic agent for the prevention and treatment of endometritis. This finding is of utmost importance in the present times when the excessive use of antibiotics has resulted in the development of antibiotic-resistant bacteria.

Carotenoids from mamey (Pouteria sapota) and carrot (Daucus carota) increase the oxidative stress resistance of Caenorhabditis elegans

Carotenoids are natural pigments and antioxidants found in fruits and vegetables such as carrot, tomato, orange, mango, yellow corn, pumpkin, and mamey. In this study, we evaluated the antioxidant potential of mamey (Pouteria sapota) carotenoids and compared them to carrot (Daucus carota) carotenoids. The carotenoids were extracted from mamey and carrot, and their antioxidant capacity were determined via in vitro (ABTS method) and in vivo assays (resistance against oxidative stress in Caenorhabditis elegans). The carotenoid contents in mamey and carrot were 4.42 ± 0.12 and 5.47 ± 0.04 mg β-carotene/100 g, respectively. Despite the differences between the carotenoid contents in both products (p < 0.05), the in vitro antioxidant capacity results showed no significant differences between the extracts (p > 0.05). The mamey and carrot carotenoid extracts decreased the oxidative damage in C. elegans by 20–30% and 30–40%, respectively. Both extracts increased the resistance and enhanced the survival of the nematodes, and showed better effects than pure β-carotene, probably owing to the complex mixture in the carotenoid extracts. These results suggest that mamey is a good alternative source of carotenoids and that it protects against oxidative stress in C. elegans. The protective effect of mamey carotenoids was similar to the effect of carrot carotenoids.

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Mamey carotenoids displayed similar antioxidant activity to carrot carotenoids.

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Mamey and carrot carotenoids increased the oxidative stress resistance of C. elegans.

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Continuous exposure to carotenoids enhanced the resistance of the progeny.

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Natural mixture of carotenoids had better antioxidant effects than pure β-carotene.

Reprogramming microorganisms for the biosynthesis of astaxanthin via metabolic engineering

There is an increasing demand for astaxanthin in food, feed, cosmetics and pharmaceutical applications because of its superior anti-oxidative and coloring properties. However, naturally produced astaxanthin is expensive, mainly due to low productivity and limited sources. Reprogramming of microorganisms for astaxanthin production via metabolic engineering is a promising strategy. We primarily focus on the application of synthetic biology, enzyme engineering and metabolic engineering in enhancing the synthesis and accumulation of astaxanthin in microorganisms in this review. We also discuss the biosynthetic pathways of astaxanthin within natural producers, and summarize the achievements and challenges in reprogramming microorganisms for enhancing astaxanthin production. This review illuminates recent biotechnological advances in microbial production of astaxanthin. Future perspectives on utilization of new technologies for boosting microbial astaxanthin production are also discussed.

Autophagy Plays a Role in the Prolongation of the Life Span of Caenorhabditis elegans by Astaxanthin

Astaxanthin (AST), a xanthophyll belonging to the family of carotenoids, is a potent antioxidant. The effect of AST on longevity and its physiological and molecular mechanism are still unclear. In this study, we proved that AST could prolong the life span of Caenorhabditis elegans. To uncover whether AST could delay aging by upregulating autophagy, we measured the expression of autophagy gene and the life span of autophagy gene bec-1 mutant nematodes, and the results showed that the expression of autophagy gene was upregulated after AST intervention and the disruption of bec-1 weakened the extension of the life span. To explore the molecular mechanism of AST-induced autophagy upregulation, we knocked out the daf-16 or hlh-30 (key genes of insulin/insulin growth factor-1 [IGF-1] signal pathway or target of rapamycin [TOR] signal pathway) by RNA interference, and the expression of autophagy gene lgg-1 decreased. Collectively, our results strongly suggest that autophagy, which is both the insulin/IGF-1 signal pathway dependent and TOR signal pathway dependent, plays a role in the prolongation of the life span of Caenorhabditis elegans by AST.

Competitive Growth Assay of Mutagenized Chlamydomonas reinhardtii Compatible With the International Space Station Veggie Plant Growth Chamber

A biological life support system for spaceflight would capture carbon dioxide waste produced by living and working in space to generate useful organic compounds. Photosynthesis is the primary mechanism to fix carbon into organic molecules. Microalgae are highly efficient at converting light, water, and carbon dioxide into biomass, particularly under limiting, artificial light conditions that are a necessity in space photosynthetic production. Although there is great promise in developing algae for chemical or food production in space, most spaceflight algae growth studies have been conducted on solid agar-media to avoid handling liquids in microgravity. Here we report that breathable plastic tissue culture bags can support robust growth of Chlamydomonas reinhardtii in the Veggie plant growth chamber, which is used on the International Space Station (ISS) to grow terrestrial plants. Live cultures can be stored for at least 1 month in the bags at room temperature. The gene set required for growth in these photobioreactors was tested using a competitive growth assay with mutations induced by short-wave ultraviolet light (UVC) mutagenesis in either wild-type (CC-5082) or cw15 mutant (CC-1883) strains at the start of the assay. Genome sequencing identified UVC-induced mutations, which were enriched for transversions and non-synonymous mutations relative to natural variants among laboratory strains. Genes with mutations indicating positive selection were enriched for information processing genes related to DNA repair, RNA processing, translation, cytoskeletal motors, kinases, and ABC transporters. These data suggest that modification of DNA repair, signal transduction, and metabolite transport may be needed to improve growth rates in this spaceflight production system.

Optimization in continuous phase-transition extraction of crude flavonoids from finger citron fruit and evaluation on their antiaging activities

The development of antiaging functional products is a hot topic in the field of functional foods. However, the efficient extraction of functional ingredients is the limiting step for the functional food industry. Continuous phase-transition extraction (CPE) is a new extraction technique that combines the advantages of Soxhlet extraction and supercritical extraction, which may have a distinct advantage over traditional methods in the extraction of flavonoids. In our study, the Box-Behnken design combined with response surface methodology was used to optimize CPE of crude flavonoids from finger citron fruit. The antiaging activities of finger citron crude flavonoids (FCCF) were evaluated by Caenorhabditis elegans (C. elegans) model. The optimal extraction conditions for CPE were as follows: ethanol concentration 85%, temperature 90°C, time 120 min, and pressure 0.2 MPa. Compared with the heat reflux extraction, the extraction rate and content of FCCF extracted by CPE increased by 24.28% and 33.22% (p < .05), respectively. FCCF extended the lifespan of C. elegans by 14.94% without causing adverse effects on their reproduction and locomotion ability. A further analysis suggested that FCCF prolonged the lifespan of nematodes under normal and oxidative stress by increasing the activity of major enzymes in endogenous antioxidant defense system and reducing the accumulation of reactive oxygen species (ROS) and malondialdehyde (MDA). The results confirmed the effectiveness of CPE in extracting crude flavonoids from finger citron fruit, and the extracted FCCF exhibited strong antiaging activities.

Evaluation of Carotenoids Protection Against Oxidative Stress in the Animal Model Caenorhabditis elegans

The nematode Caenorhabditis elegans is a versatile and powerful model organism for animal experimental research and, despite being an invertebrate, displays remarkably similar molecular bases and conserved cellular pathways to those of humans. Oxidative stress is an etiological factor that influences numerous diseases, degenerative processes and aging. C. elegans has revealed as an opportune and feasible organism to investigate the antioxidant effects of different bioactives or complex food matrices, and a number of protocols have been developed by using different oxidative stressors. Carotenoids are recognized as quenchers and scavengers of reactive oxygen species, and many of their related health benefits attributed in the diet are tightly linked to their antioxidant properties. In this chapter, we report a simple and rapid assay to evaluate the protection capacity of pure carotenoids or complex carotenoid extracts against oxidative stress in the model system C. elegans. The protocol describes a representative feeding experiment by adding carotenoids to the nematode growth medium and after an incubation period, the C. elegans populations fed with carotenoids are exposed to an acute oxidative stress by using H₂O₂ as oxidative agent. The protection against oxidative stress is evaluated as the survival rate of the nematodes fed with the carotenoid prior to receiving oxidative treatment compared with the survival rate of control nematode population. In order to confirm the carotenoid intake by the nematodes during the feeding experiment a bioassimilation experiment is also reported.

Disruption of Phaffia rhodozyma cells and preparation of microencapsulated astaxanthin with high water solubility

A novel process was developed for encapsulation of astaxanthin from Phaffia rhodozyma. The yeast cells were disrupted by glass beads and the high shearing force partially emulsified the astaxanthin in aqueous phase. The enzymolysis method was then adopted to prepare the yeast extract for a full use of the cells. The gelatin and porous starch were used to microencapsulate the emulsified astaxanthin. Under optimized conditions, the recovery of amino nitrogen and solid reached 3.68 ± 0.32% and 49.22 ± 2.34%, respectively. The microencapsulation conditions were optimized through orthogonal experiment and the encapsulation efficiency, loading astaxanthin, and amino-nitrogen reached 88.56%, 1.55 mg/g, and 1.35 ± 0.14%, respectively. The water solubility of microcapsules reached 81.5 ± 0.35%. Color and storage stability analysis showed that microencapsulation of astaxanthin possessed higher thermal stability. The results demonstrated that the established process was effective and practical.

β-Cryptoxanthin Reduces Body Fat and Increases Oxidative Stress Response in Caenorhabditis elegans Model

β-Cryptoxanthin (BCX) is a major dietary pro-vitamin A carotenoid, found mainly in fruits and vegetables. Several studies showed the beneficial effects of BCX on different aspects of human health. In spite of the evidence, the molecular mechanisms of action of BCX need to be further investigated. The Caenorhabditis elegans model was used to analyze in vivo the activity of BCX on fat reduction and protection to oxidative stress. Dose-response assays provided evidence of the efficacy of BCX at very low dose (0.025 µg/mL) (p < 0.001) on these processes. Moreover, a comparative analysis with other carotenoids, such as lycopene and β-carotene, showed a stronger effect of BCX. Furthermore, a transcriptomic analysis of wild-type nematodes supplemented with BCX revealed upregulation of the energy metabolism, response to stress, and protein homeostasis as the main metabolic targets of this xanthophyll. Collectively, this study provides new in vivo evidence of the potential therapeutic use of BCX in the prevention of diseases related to metabolic syndrome and aging.

Preliminary characterization of the structure and immunostimulatory and anti-aging properties of the polysaccharide fraction ofHaematococcus pluvialis

In this study, a polysaccharide fraction (HPP-c3-s1) was obtained from Haematococcus pluvialis using DEAE-52 anion exchange and Sephacryl S400 chromatographies. The structure of HPP-c3-s1 was partially characterized and its biological activity was investigated. HPP-c3-s1 is a homogeneous polysaccharide with a molecular weight of 23 413 kDa as determined by high-performance gel permeation chromatography and polyacrylamide gel electrophoresis. Periodate oxidation and Smith degradation analysis combined with GC-MS determined that HPP-c3-s1 contains 1 → 2, 1 → 3, 1 → 4, and probably a few 1 → 6 glycosyl linkages. Fourier transform infrared spectroscopy and nuclear magnetic resonance analyses indicate HPP-c3-s1 is a pyranose containing an amino and O-acetyl group. The sugar chains in HPP-c3-s1 contain both α and β glycosidic configurations, where the β configuration is the primary form. It was observed that the HPP-c3-s1 nanostructure had linear and branched forms at a concentration of 5 μg mL⁻¹ and created different sized aggregates at a higher concentration of 50 μg mL⁻¹. Furthermore, HPP-c3-s1 had significant immunostimulatory effects on splenocytes and B lymphocytes. In assays assessing anti-aging effects, HPP-c3-s1 extended the mean survival of Caenorhabditis elegans without adversely affecting reproduction. In addition, treatment with HPP-c3-s1 resulted in delays in age-related physiologic parameters, including body movement, rates of head swing and body bending, and accumulation of intestinal lipofuscinosis in C. elegans. Overall, these results suggest HPP-c3-s1 has remarkable immunomodulatory and anti-aging properties that may serve as the basis for development of functional foods and dietary supplements.

HPP-c3-s1 is a pyranose with an average molecular weights of 23 413 kDa, which exhibited siginificant immunomodulatory and anti-aging activities.

Neuroprotective mechanisms of astaxanthin: a potential therapeutic role in preserving cognitive function in age and neurodegeneration

Astaxanthin (AXT) is a carotenoid with multiple health benefits. It is currently marketed as a health supplement and is well known for its antioxidant capacity. Recent evidence has emerged to suggest a broad range of biological activities. The interest in this compound has increased dramatically over the last few years and many studies are now applying this molecule across many disease models. Results from the current research are beginning to come together to suggest neuroprotective properties including anti-inflammatory, anti-apoptotic, and antioxidant effects, as well as the potential to promote or maintain neural plasticity. These emergent mechanisms of actions implicate AXT as a promising therapeutic agent for neurodegenerative disease. This review will examine and extrapolate from the recent literature to build support for the use of AXT in mitigating neuropathy in normal aging and neurodegenerative disease.

Cytoproliferative and Cytoprotective Effects of Striatisporolide A Isolated from Rhizomes of Athyrium multidentatum (Doell.) Ching on Human Umbilical Vein Endothelial Cells

OBJECTIVES

The aim of this study was to investigate the proliferative and protective effects of striatisporolide A (SA) obtained from the rhizomes of Athyrium multidentatum (Doell.) Ching on human umbilical vein endothelial cells (HUVECs).

METHODS

Cell viability was measured by the MTT method. Cell apoptosis was determined by flow cytometry. Intracellular ROS was measured by the 2,7-dichlorodihydrofluorescein diacetate (DCFH-DA) fluorescent probe.

RESULTS

The viability rate in cells treated with 100 µM SA alone was increased to 128.72% ± 0.19% and showed a significant difference compared with the control group (p < 0.05). Meanwhile, SA augmented the cell viabilities in H₂O₂-treated HUVECs, and the cell viability was enhanced to 56.94% ± 0.13% (p < 0.01) when pre-incubated with 50 µM SA. The cell apoptosis rates were reduced to 2.17% ± 0.20% (p < 0.05) and 3.1% ± 0.34% (p < 0.01), respectively, after treatment with SA alone or SA/H₂O₂. SA inhibited the overproduction of reactive oxygen species (ROS) in HUVECs induced by H₂O₂ and the fluorescent intensity was abated to 9.47 ± 0.61 after pre-incubated with 100 μM SA.

CONCLUSIONS

The biological activities of SA were explored for the first time. Our results stated that SA exhibited significant cytoproliferative and minor cytoprotective effects on HUVECs. We presume that the mechanisms of the proliferation and protection actions of SA involve interference with the generation of ROS and the cell apoptosis. These findings provide a new perspective on the biological potential of butenolides.