Astaxanthin prevents in vitro auto-oxidative injury in human lymphocytes

Dehydrozingerone ameliorates arsenic-induced reproductive toxicity in male Wistar rats

Arsenic (As3+), a significant environmental pollutant that has garnered global attention, is widely recognized for its adverse effects on reproductive health. This study assesses the aphrodisiac activity of Dehydrozingerone (DHZ) against As3+ induced sexual dysfunction in male Wistar rats. Male Wistar rats were divided into control, As3+, and As3++DHZ groups. The As3+ group received 5 mg/kg sodium arsenite (NaAsO2) orally while As3++DHZ group received 50 mg/kg synthesized DHZ along with As3+ for 42 days. Following administration, mount and intromission latency, frequency, and average time were measured to assess aphrodisiac and reproductive toxicity in male Wistar rats which had 1:1 coitus with female rats. On days 14th, 28th, and 42nd, sexual behaviour was measured. Further on 43rd day, animals were sacrificed, blood was collected to measure oxidative parameters and LH hormone, and then testes were collected to profile reproductive damage. As3+ treated rats had lower sperm counts, motility, and abnormalities. These alterations reduced sexual hormones. In addition, As3+ toxicity depleted antioxidant indicators including SOD, GSH and elevated ROS. Compared to the As3+ group, As3++DHZ showed a substantial (p < 0.05) increase in sperm count, motility, and reduced abnormalities. DHZ also reversed the rise in luteinizing hormone caused by As3+ therapy, restored oxidative indicators, and improved seminiferous tubule structural damage. 42 days As3+ exposure slightly increased rats' sexual desire but not sperm quality. However, As3++DHZ lower libido and sperm quality. Thus, DHZ therapy enhanced rat sexual desire and sperm quality compared to As3+.

The Clinical Promise of Microalgae in Rheumatoid Arthritis: From Natural Compounds to Recombinant Therapeutics

Rheumatoid arthritis (RA) is an invalidating chronic autoimmune disorder characterized by joint inflammation and progressive bone damage. Dietary intervention is an important component in the treatment of RA to mitigate oxidative stress, a major pathogenic driver of the disease. Alongside traditional sources of antioxidants, microalgae-a diverse group of photosynthetic prokaryotes and eukaryotes-are emerging as anti-inflammatory and immunomodulatory food supplements. Several species accumulate therapeutic metabolites-mainly lipids and pigments-which interfere in the pro-inflammatory pathways involved in RA and other chronic inflammatory conditions. The advancement of the clinical uses of microalgae requires the continuous exploration of phytoplankton biodiversity and chemodiversity, followed by the domestication of wild strains into reliable producers of said metabolites. In addition, the tractability of microalgal genomes offers unprecedented possibilities to establish photosynthetic microbes as light-driven biofactories of heterologous immunotherapeutics. Here, we review the evidence-based anti-inflammatory mechanisms of microalgal metabolites and provide a detailed coverage of the genetic engineering strategies to enhance the yields of endogenous compounds and to develop innovative bioproducts.

Formyl peptide receptors are involved in CTX-induced impairment of lymphocyte functions

Crotoxin (CTX) is a neurotoxin that is isolated from the venom of Crotalus durissus terrificus, which displays immunomodulatory, anti-inflammatory, and anti-tumoral effects. Previous research has demonstrated that CTX promotes the adherence of leukocytes to the endothelial cells in blood microcirculation and the high endothelial venules of lymph nodes, which reduces the number of blood cells and lymphocytes. Studies have also shown that these effects are mediated by lipoxygenase-derived mediators. However, the exact lipoxygenase-derived eicosanoid involved in the CTX effect on lymphocytes is yet to be characterized. As CTX stimulates lipoxin-derived mediators from macrophages and lymphocyte effector functions could be modulated by activating formyl peptide receptors, we aimed to investigate whether these receptors were involved in CTX-induced redistribution and functions of lymphocytes in rats. We used male Wistar rats treated with CTX to demonstrate that Boc2 (butoxycarbonyl-Phe-Leu-Phe-Leu-Phe), an antagonist of formyl peptide receptors, prevented CTX-induced decrease in the number of circulating lymphocytes and increased the expression of the lymphocyte adhesion molecule LFA1. CTX reduced the T and B lymphocyte functions, such as lymphocyte proliferation in response to the mitogen Concanavalin A and antibody production in response to BSA immunization, respectively, which was prevented by the administration of Boc2. Importantly, mesenteric lymph node lymphocytes from CTX-treated rats showed an increased release of 15-epi-LXA₄. These results indicate that formyl peptide receptors mediate CTX-induced redistribution of lymphocytes and that 15-epi-LXA₄ is a key mediator of the immunosuppressive effects of CTX.

Mechanistic role of astaxanthin derived from shrimp against certain metabolic disorders

Oxidative stress caused by the imbalance between production of oxidants and antioxidants in the body leads to the development of different ailments. The bioactive compounds derived from marine sources are considered to be safe and appropriate to use. Astaxanthin possesses antioxidant activity about 100-500 times higher than other antioxidants such as α-tocopherol and β-carotene. It has numerous health benefits and vital pharmacological properties for the treatment of diseases like diabetes, hypertension, cancer, heart disease, ischemia, neurological disorders, and potential role in liver enzyme gamma-glutamyl transpeptidase which has significance in medicine as a diagnostic marker. The primary source of astaxanthin among crustaceans is shrimps and the presence of astaxanthin protects shrimps from oxidation of polyunsaturated fatty acids and cholesterol. Conclusively, astaxanthin derived from shrimps is very effective against oxidative stress which can lead to certain ailments.

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.

Microalgae Derived Astaxanthin: Research and Consumer Trends and Industrial Use as Food

Astaxanthin is a high-value carotenoid currently being produced by chemical synthesis and by extraction from the biomass of the microalga Haematococcus pluvialis. Other microalgae, such as Chlorella zofingiensis, have the potential for being used as sources of astaxanthin. The differences between the synthetic and the microalgae derived astaxanthin are notorious: not only their production and price but also their uses and bioactivity. Microalgae derived astaxanthin is being used as a pigment in food and feed or aquafeed production and also in cosmetic and pharmaceutical products. Several health-promoting properties have been attributed to astaxanthin, and these were summarized in the current review paper. Most of these properties are attributed to the high antioxidant capacity of this molecule, much higher than that of other known natural compounds. The aim of this review is to consider the main challenges and opportunities of microalgae derived products, such as astaxanthin as food. Moreover, the current study includes a bibliometric analysis that summarizes the current research trends related to astaxanthin. Moreover, the potential utilization of microalgae other than H. pluvialis as sources of astaxanthin as well as the health-promoting properties of this valuable compound will be discussed.

Antioxidant and anti‑inflammatory mechanisms of action of astaxanthin in cardiovascular diseases (Review)

Cardiovascular diseases are the most common cause of mortality worldwide. Oxidative stress and inflammation are pathophysiological processes involved in the development of cardiovascular diseases; thus, anti‑inflammatory and antioxidant agents that modulate redox balance have become research targets so as to evaluate their molecular mechanisms of action and therapeutic properties. Astaxanthin, a carotenoid of the xanthophyll group, has potent antioxidant properties due to its molecular structure and its arrangement in the plasma membrane, factors that favor the neutralization of reactive oxygen and nitrogen species. This carotenoid also has prominent anti‑inflammatory activity, possibly interrelated with its antioxidant effect, and is also involved in the modulation of lipid and glucose metabolism. Considering the potential beneficial effects of astaxanthin on cardiovascular health evidenced by preclinical and clinical studies, the aim of the present review was to describe the molecular and cellular mechanisms associated with the antioxidant and anti‑inflammatory properties of this carotenoid in cardiovascular diseases, particularly atherosclerosis. The beneficial properties and safety profile of astaxanthin indicate that this compound may be used for preventing progression or as an adjuvant in the treatment of cardiovascular diseases.

Roles of Carotenoids in Invertebrate Immunology

Carotenoids are biologically active pigments that are well-known to enhance the defense and immunity of the vertebrate system. However, in invertebrates, the role of carotenoids in immunity is not clear. Therefore, this study aims to review the scientific evidence for the role of carotenoids in invertebrate immunization. From the analysis of published literatures and recent studies from our laboratory, it is obvious that carotenoids are involved in invertebrate immunity in two ways. On the one hand, carotenoids can act as antioxidant enzymes to remove singlet oxygen, superoxide anion radicals, and hydroxyl radicals, thereby reducing SOD activity and reducing the cost of immunity. In some organisms, carotenoids have been shown to promote SOD activity by up-regulating the expression of the ZnCuSOD gene. Carotenoids, on the other hand, play a role in the expression and regulation of many genes involved in invertebrate immunity, including thioredoxins (TRX), peptidoglycan recognition receptor proteins (PGRPs), ferritins, prophenoloxidase (ProPO), vitellogenin (Vg), toll-like receptor (TLRs), heat shock proteins (HSPs), and CuZnSOD gene. The information in this review is very useful for updating our understanding of the progress of carotenoid research in invertebrate immunology and to help identify topics for future topics.

Astaxanthin Protects PC12 Cells against Homocysteine- and Glutamate-Induced Neurotoxicity

Memory impairment has been shown to be associated with glutamate (Glu) excitotoxicity, homocysteine (Hcy) accumulation, and oxidative stress. We hypothesize that Glu and Hcy could damage neuronal cells, while astaxanthin (ATX) could be beneficial to alleviate the adverse effects. Using PC12 cell model, we showed that Glu and Hcy provoked a huge amount of reactive oxygen species (ROS) production, causing mitochondrial damage at EC₅₀ 20 and 10 mm, respectively. The mechanisms of action include: (1) increasing calcium influx; (2) producing ROS; (3) initiating lipid peroxidation; (4) causing imbalance of the Bcl-2/Bax homeostasis; and (5) activating cascade of caspases involving caspases 12 and 3. Conclusively, the damages caused by Glu and Hcy to PC12 cells can be alleviated by the potent antioxidant ATX.

Chemically-Induced Production of Anti-Inflammatory Molecules in Microalgae

Microalgae have been widely recognized as a valuable source of natural, bioactive molecules that can benefit human health. Some molecules of commercial value synthesized by the microalgal metabolism have been proven to display anti-inflammatory activity, including the carotenoids lutein and astaxanthin, the fatty acids EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid), and sulphated polysaccharides. These molecules can accumulate to a certain extent in a diversity of microalgae species. A production process could become commercially feasible if the productivity is high and the overall production process costs are minimized. The productivity of anti-inflammatory molecules depends on each algal species and the cultivation conditions, the latter being mostly related to nutrient starvation and/or extremes of temperature and/or light intensity. Furthermore, novel bioprocess tools have been reported which might improve the biosynthesis yields and productivity of those target molecules and reduce production costs simultaneously. Such novel tools include the use of chemical triggers or enhancers to improve algal growth and/or accumulation of bioactive molecules, the algal growth in foam and the surfactant-mediated extraction of valuable compounds. Taken together, the recent findings suggest that the combined use of novel bioprocess strategies could improve the technical efficiency and commercial feasibility of valuable microalgal bioproducts production, particularly anti-inflammatory compounds, in large scale processes.

Astaxanthin Restrains Nitrative-Oxidative Peroxidation in Mitochondrial-Mimetic Liposomes: A Pre-Apoptosis Model

Astaxanthin (ASTA) is a ketocarotenoid found in many marine organisms and that affords many benefits to human health. ASTA is particularly effective against radical-mediated lipid peroxidation, and recent findings hypothesize a “mitochondrial-targeted” action of ASTA in cells. Therefore, we examined the protective effects of ASTA against lipid peroxidation in zwitterionic phosphatidylcholine liposomes (PCLs) and anionic phosphatidylcholine: phosphatidylglycerol liposomes (PCPGLs), at different pHs (6.2 to 8.0), which were challenged by oxidizing/nitrating conditions that mimic the regular and preapoptotic redox environment of active mitochondria. Pre-apoptotic conditions were created by oxidized/nitr(osyl)ated cytochrome c and resulted in the highest levels of lipoperoxidation in both PCL and PCPGLs (pH 7.4). ASTA was less protective at acidic conditions, especially in anionic PCPGLs. Our data demonstrated the ability of ASTA to hamper oxidative and nitrative events that lead to cytochrome c-peroxidase apoptosis and lipid peroxidation, although its efficiency changes with pH and lipid composition of membranes.

Uncovering Potential Applications of Cyanobacteria and Algal Metabolites in Biology, Agriculture and Medicine: Current Status and Future Prospects

Cyanobacteria and algae having complex photosynthetic systems can channelize absorbed solar energy into other forms of energy for production of food and metabolites. In addition, they are promising biocatalysts and can be used in the field of "white biotechnology" for enhancing the sustainable production of food, metabolites, and green energy sources such as biodiesel. In this review, an endeavor has been made to uncover the significance of various metabolites like phenolics, phytoene/terpenoids, phytols, sterols, free fatty acids, photoprotective compounds (MAAs, scytonemin, carotenoids, polysaccharides, halogenated compounds, etc.), phytohormones, cyanotoxins, biocides (algaecides, herbicides, and insecticides) etc. Apart from this, the importance of these metabolites as antibiotics, immunosuppressant, anticancer, antiviral, anti-inflammatory agent has also been discussed. Metabolites obtained from cyanobacteria and algae have several biotechnological, industrial, pharmaceutical, and cosmetic uses which have also been discussed in this review along with the emerging technology of their harvesting for enhancing the production of compounds like bioethanol, biofuel etc. at commercial level. In later sections, we have discussed genetically modified organisms and metabolite production from them. We have also briefly discussed the concept of bioprocessing highlighting the functioning of companies engaged in metabolites production as well as their cost effectiveness and challenges that are being addressed by these companies.

Microalgae as healthy ingredients for functional food: a review

Microalgae are very interesting and valuable natural sources of highly valuable bioactive compounds, such as vitamins, essential amino acids, polyunsaturated fatty acids, minerals, carotenoids, enzymes and fibre.

Astaxanthin Inhibits Proliferation and Induces Apoptosis and Cell Cycle Arrest of Mice H22 Hepatoma Cells

Background

It is widely recognized that astaxanthin (ASX), a member of the carotenoid family, has strong biological activities including antioxidant, anti-inflammation, and immune-modulation activities. Previous studies have confirmed that ASX can effectively inhibit hepatoma cells in vitro.

Material/Methods

MTT was used to assay proliferation of mice H22 cells, and flow cytometry was used to determine apoptosis and cell cycle arrest of H22 cells in vitro and in vivo. Moreover, anti-tumor activity of ASX was observed in mice.

Results

ASX inhibited the proliferation of H22 cells, promoted cell necrosis, and induced cell cycle arrest in G2 phase in vitro and in vivo.

Conclusions

This study indicated that ASX can inhibit proliferation and induce apoptosis and cell cycle arrest in mice H22 hepatoma cells in vitro and in vivo.

Krill oil reduces intestinal inflammation by improving epithelial integrity and impairing adherent-invasive Escherichia coli pathogenicity

BACKGROUND

Krill oil is a marine derived oil rich in phospholipids, astaxanthin and omega-3 fatty acids. Several studies have found benefits of krill oil against oxidative and inflammatory damage.

AIMS

We aimed at assessing the ability of krill oil to reduce intestinal inflammation by improving epithelial barrier integrity, increasing cell survival and reducing pathogenicity of adherent-invasive Escherichia coli.

METHODS

CACO2 and HT29 cells were exposed to cytomix (TNFα and IFNγ) to induce inflammation and co-exposed to cytomix and krill oil. E-cadherin, ZO-1 and F-actin levels were analyzed by immunofluorescence to assess barrier integrity. Scratch test was performed to measure wound healing. Cell survival was analyzed by flow cytometry. Adherent-invasive Escherichia coli LF82 was used for adhesion/invasion assay.

RESULTS

In inflamed cells E-cadherin and ZO-1 decreased, with loss of cell-cell adhesion, and F-actin polymerization increased stress fibres; krill oil restored initial conditions and improved wound healing, reduced bacterial adhesion/invasion in epithelial cells and survival within macrophages; krill oil reduced LF82-induced mRNA expression of pro-inflammatory cytokines.

CONCLUSIONS

Krill oil improves intestinal barrier integrity and epithelial restitution during inflammation and controls bacterial adhesion and invasion to epithelial cells. Thus, krill oil may represent an innovative tool to reduce intestinal inflammation.

Mitochondrion-Permeable Antioxidants to Treat ROS-Burst-Mediated Acute Diseases

Reactive oxygen species (ROS) play a crucial role in the inflammatory response and cytokine outbreak, such as during virus infections, diabetes, cancer, cardiovascular diseases, and neurodegenerative diseases. Therefore, antioxidant is an important medicine to ROS-related diseases. For example, ascorbic acid (vitamin C, VC) was suggested as the candidate antioxidant to treat multiple diseases. However, long-term use of high-dose VC causes many side effects. In this review, we compare and analyze all kinds of mitochondrion-permeable antioxidants, including edaravone, idebenone, α-Lipoic acid, carotenoids, vitamin E, and coenzyme Q10, and mitochondria-targeted antioxidants MitoQ and SkQ and propose astaxanthin (a special carotenoid) to be the best antioxidant for ROS-burst-mediated acute diseases, like avian influenza infection and ischemia-reperfusion. Nevertheless, astaxanthins are so unstable that most of them are inactivated after oral administration. Therefore, astaxanthin injection is suggested hypothetically. The drawbacks of the antioxidants are also reviewed, which limit the use of antioxidants as coadjuvants in the treatment of ROS-associated disorders.

Astaxanthin Protecting Membrane Integrity against Photosensitized Oxidation through Synergism with Other Carotenoids

Incorporation of astaxanthin or zeaxanthin in giant unilamellar vesicles (GUVs) of phosphatidylcholine resulted in a longer lag phase than incorporation of β-carotene or lycopene for the onset of budding induced by chlorophyll a photosensitization and quantified by a dimensionless entropy parameter using optical microscopy and digital image heterogeneity analysis. The lowest initial rate of GUV budding after the lag phase was seen for GUVs with astaxanthin as the least reducing carotenoid, while the lowest final level of entropy appeared for those with lycopene or β-carotene as a more reducing carotenoid. The combination of astaxanthin and lycopene gave optimal protection against budding with respect to both a longer lag phase and lower final level of entropy by combining good electron acceptance and good electron donation. Quenching of singlet oxygen by carotenoids close to chlorophyll a in the membrane interior in parallel with scavenging of superoxide radicals by astaxanthin anchored in the surface may explain the synergism between carotenoids involving both type I and type II photosensitization by chlorophyll a.

Redox Status and Neuro Inflammation Indexes in Cerebellum and Motor Cortex of Wistar Rats Supplemented with Natural Sources of Omega-3 Fatty Acids and Astaxanthin: Fish Oil, Krill Oil, and Algal Biomass

Health authorities worldwide have consistently recommended the regular consumption of marine fishes and seafood to preserve memory, sustain cognitive functions, and prevent neurodegenerative processes in humans. Shrimp, crabs, lobster, and salmon are of particular interest in the human diet due to their substantial provision of omega-3 fatty acids (n-3/PUFAs) and the antioxidant carotenoid astaxanthin (ASTA). However, the optimal ratio between these nutraceuticals in natural sources is apparently the key factor for maximum protection against most neuro-motor disorders. Therefore, we aimed here to investigate the effects of a long-term supplementation with (n-3)/PUFAs-rich fish oil, ASTA-rich algal biomass, the combination of them, or krill oil (a natural combination of both nutrients) on baseline redox balance and neuro-inflammation indexes in cerebellum and motor cortex of Wistar rats. Significant changes in redox metabolism were only observed upon ASTA supplementation, which reinforce its antioxidant properties with a putative mitochondrial-centered action in rat brain. Krill oil imposed mild astrocyte activation in motor cortex of Wistar rats, although no redox or inflammatory index was concomitantly altered. In summary, there is no experimental evidence that krill oil, fish oil, oralgal biomass (minor variation), drastically change the baseline oxidative conditions or the neuro-inflammatory scenario in neuromotor-associated rat brain regions.

Exploring the potential of using algae in cosmetics

The applications of microalgae in cosmetic products have recently received more attention in the treatment of skin problems, such as aging, tanning and pigment disorders. There are also potential uses in the areas of anti-aging, skin-whitening, and pigmentation reduction products. While algae species have already been used in some cosmetic formulations, such as moisturizing and thickening agents, algae remain largely untapped as an asset in this industry due to an apparent lack of utility as a primary active ingredient. This review article focuses on integrating studies on algae pertinent to skin health and beauty, with the purpose of identifying serviceable algae functions in practical cosmetic uses.

Astaxanthin protects steroidogenesis from hydrogen peroxide-induced oxidative stress in mouse Leydig cells

Androgens, especially testosterone produced in Leydig cells, play an essential role in development of the male reproductive phenotype and fertility. However, testicular oxidative stress may cause a decline in testosterone production. Many antioxidants have been used as reactive oxygen species (ROS) scavengers to eliminate oxidative stress to protect steroidogenesis. Astaxanthin (AST), a natural extract from algae and plants ubiquitous in the marine environment, has been shown to have antioxidant activity in many previous studies. In this study, we treated primary mouse Leydig cells or MA-10 cells with hydrogen peroxide (H₂O₂) to cause oxidative stress. Testosterone and progesterone production was suppressed and the expression of the mature (30 kDa) form of StAR protein was down-regulated in MA-10 cells by H₂O₂ and cAMP co-treatment. However, progesterone production and expression of mature StAR protein were restored in MA-10 cells by a one-hour pretreatment with AST. AST also reduced ROS levels in cells so that they were lower than the levels in untreated controls. These results provide additional evidence of the potential health benefits of AST as a potential food additive to ease oxidative stress.

Comparative effect of fucoxanthin and vitamin C on oxidative and functional parameters of human lymphocytes

The aim of this study was to evaluate the effects of FUCO alone or combined with vitamin C on different features of lymphocyte function related to ROS/RNS (reactive oxygen/nitrogen species) production. For this purpose we have evaluated the cytotoxicity of increasing concentrations of FUCO and vitamin C, the proliferative capacity of stimulated T- and B-lymphocytes, superoxide anion radicals (O(2)), hydrogen peroxide (H(2)O(2)) and nitric oxide (NO) production, antioxidant enzyme activities and the indexes of oxidative damage in proteins (carbonyl and thiol content). We have also evaluated the release of inflammatory cytokines and glucose-6-phosphate dehydrogenase (G6PDH) activity. Healthy human lymphocytes were acutely treated in vitro with FUCO (2 μM) with or without vitamin C (100 μM). Results revealed that human lymphocytes treated with FUCO at 2μM did not present any significant alteration in the proliferation of T- and B-lymphocytes at both resting and stimulated conditions. Moreover, FUCO used at low concentrations showed more pro-oxidant than antioxidant effects, which were recognized by the increased H(2)O(2) and increased NO production. Anti-inflammatory activity of FUCO was confirmed by significantly increased IL-10 and decreased TNF-α production. Vitamin C increased T-lymphocyte proliferation, whereas vitamin C plus FUCO promoted a reduction in the proliferation rate of these cells. All groups decreased pro-inflammatory cytokine TNF-α and increased anti-inflammatory IL-10 production although only vitamin C decreased IFN-γ either alone or when combined with FUCO. Overall, the combination of the antioxidants had more antioxidant and anti-inflammatory effects than when they were applied alone.

Neuroprotective properties of the marine carotenoid astaxanthin and omega-3 fatty acids, and perspectives for the natural combination of both in krill oil

The consumption of marine fishes and general seafood has long been recommended by several medical authorities as a long-term nutritional intervention to preserve mental health, hinder neurodegenerative processes, and sustain cognitive capacities in humans. Most of the neurological benefits provided by frequent seafood consumption comes from adequate uptake of omega-3 and omega-6 polyunsaturated fatty acids, n-3/n-6 PUFAs, and antioxidants. Optimal n-3/n-6 PUFAs ratios allow efficient inflammatory responses that prevent the initiation and progression of many neurological disorders. Moreover, interesting in vivo and clinical studies with the marine antioxidant carotenoid astaxanthin (present in salmon, shrimp, and lobster) have shown promising results against free radical-promoted neurodegenerative processes and cognition loss. This review presents the state-of-the-art applications of n-3/n-6 PUFAs and astaxanthin as nutraceuticals against neurodegenerative diseases associated with exacerbated oxidative stress in CNS. The fundamental “neurohormesis” principle is discussed throughout this paper. Finally, new perspectives for the application of a natural combination of the aforementioned anti-inflammatory and antioxidant agents (found in krill oil) are also presented herewith.

Glycolaldehyde impairs neutrophil biochemical parameters by an oxidative and calcium-dependent mechanism--protective role of antioxidants astaxanthin and vitamin C

AIM

The present study examined the effects of glycolaldehyde (GC) on biochemical parameters of human neutrophils and whether the antioxidant astaxanthin associated with vitamin C can modulate these parameters.

METHODS

Neutrophils from healthy subjects were treated with GC (1mM) followed or not by the antioxidants astaxanthin (2 μM) and vitamin C (100 μM). We examined the phagocytic capacity, hypochlorous acid, myeloperoxidase (MPO) and glucose-6-phosphate dehydrogenase (G6PDH) activities, cytokines and [Ca(2+)](i). Also, superoxide anion, hydrogen peroxide, nitric oxide production, antioxidant enzyme activities and glutathione-recycling system were evaluated.

RESULTS

GC promoted a marked reduction on the phagocytic capacity, maximal G6PDH and MPO activities, hypochlorous acid production and release of IL-1β, IL-6 and TNF-α cytokines. Some impairment in the neutrophils biochemical parameters appears to be mediated by oxidative stress through ROS/RNS production and calcium reduction. Oxidative stress was evidenced by reduction in the activities of the main antioxidant enzymes, GSH/GSSG ratio and in the increment of O(2)(-) and H(2)O(2) and NO.

CONCLUSIONS

Treatment of cells with the combination of the antioxidants astaxanthin and vitamin C was able to restore some neutrophils function mainly by decreasing ROS/RNS production and improving the redox state. Overall, our findings demonstrate that GC modulates several neutrophils biochemical parameters in vitro.

Hepatoprotective potential of astaxanthin against 2,3,7,8-tetrachlorodibenzo-p-dioxin in cultured rat hepatocytes

The purpose of this study was to evaluate the effect of carotenoid astaxanthin (ASTA) on cultured primary rat hepatocytes treated with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) on the cell viability (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide, MTT), lactate dehydrogenase (LDH) activity, 8-oxo-2-deoxyguanosine (8-OH-dG), total antioxidant capacity (TAC), and total oxidative stress (TOS) levels, and liver micronucleus rates. ASTA (2.5, 5, and 10 µM) was added to cultures alone or simultaneously with TCDD (5 and 10 µM) for 48 h. The results of MTT and LDH assays showed that both doses of TCDD caused significant decrease in cell viability. Also, TCDD significantly increased TOS and decreased TAC level in rat hepatocytes. On the basis of increasing doses, the dioxin caused significant increase in micronucleated hepatocytes) and 8-OH-dG level as compared to control culture. The presence of ASTA with TCDD minimized its effects on primary hepatocytes cultures and DNA damages.

Carotenoids in antioxidant networks. Colorants or radical scavengers

Optical and electronic properties of carotenoids as also reflected in their colors have been fine-tuned through evolution, resulting in a structural diversity important for carotenoid properties as radical scavengers and as quenchers of electronically excited states. Carotenoids form antioxidant networks based on one-electron transfer with other carotenoids depending on the balance between ionization energy and electron affinity of the individual carotenoids as has been demonstrated by real-time kinetic studies and later confirmed by quantum mechanical calculations. The more hydrophilic xanthophylls serve as molecular wiring across membranes in these networks through anchoring in water/lipid interfaces resulting in synergism with more lipophilic carotenoids. Radical scavenging of such networks seems to be thermodynamically controlled according to a two-dimensional classification of potential antioxidants. Carotenoids in birds' plumage, as reflected by their color and color intensity, seem to be indicators of good antioxidant status and health of the bird, and such antioxidant networks appear to be in "equilibrium". Carotenoids are under other conditions involved in networks with other types of antioxidants as in egg yolk and in some fish. For the more hydrophilic (iso)flavonoids and their glycosides, antioxidant synergism through regeneration of the lipophilic carotenoids active as radical scavengers becomes kinetically controlled at interfaces. Carotenoids appear accordingly, and also in food, as antioxidants under two types of conditions: (i) in "equilibrium" with other antioxidants in thermodynamically controlled networks serving as color indicators of good antioxidant status and (ii) as antioxidants active through radical scavenging in networks with kinetically controlled regeneration.

Combined fish oil and astaxanthin supplementation modulates rat lymphocyte function

PURPOSE

Higher intakes of n-3 polyunsaturated fatty acids that are abundant in marine fishes have been long described as a "good nutritional intervention" with increasing clinical benefits to cardiovascular health, inflammation, mental, and neurodegenerative diseases. The present study was designed to investigate the effect of daily fish oil (FO-10 mg EPA/kg body weight (BW) and 7 mg DHA/kg BW) intake by oral gavage associated with the antioxidant astaxanthin (ASTA-1 mg/kg BW) on the redox metabolism and the functional properties of lymphocytes from rat lymph nodes.

METHODS

This study was conducted by measurements of lymphocyte proliferation capacity, ROS production [superoxide (O₂(•-)) and hydrogen peroxide (H₂O₂)], nitric oxide (NO(•)) generation, intracellular calcium release, oxidative damage to lipids and proteins, activities of major antioxidant enzymes, GSH/GSSG content, and cytokines release.

RESULTS

After 45 days of FO + ASTA supplementation, the proliferation capacity of activated T- and B-lymphocytes was significantly diminished followed by lower levels of O₂(•-), H₂O₂ and NO(•) production, and increased activities of total/SOD, GR and GPx, and calcium release in cytosol. ASTA was able to prevent oxidative modification in cell structures through the suppression of the oxidative stress condition imposed by FO. L: -selectin was increased by FO, and IL-1β was decreased only by ASTA supplementation.

CONCLUSION

We can propose that association of ASTA with FO could be a good strategy to prevent oxidative stress induced by polyunsaturated fatty acids and also to potentiate immuno-modulatory effects of FO.

Astaxanthin limits fish oil-related oxidative insult in the anterior forebrain of Wistar rats: putative anxiolytic effects?

The habitual consumption of marine fish is largely associated to human mental health. Fish oil is particularly rich in n-3 polyunsaturated fatty acids that are known to play a role in several neuronal and cognitive functions. In parallel, the orange-pinkish carotenoid astaxanthin (ASTA) is found in salmon and displays important antioxidant and anti-inflammatory properties. Many neuronal dysfunctions and anomalous psychotic behavior (such as anxiety, depression, etc.) have been strongly related to the higher sensitivity of cathecolaminergic brain regions to oxidative stress. Thus, the aim of this work was to study the combined effect of ASTA and fish oil on the redox status in plasma and in the monoaminergic-rich anterior forebrain region of Wistar rats with possible correlations with the anxiolytic behavior. Upon fish oil supplementation, the downregulation of superoxide dismutase and catalase activities combined to increased "free" iron content resulted in higher levels of lipid and protein oxidation in the anterior forebrain of animals. Such harmful oxidative modifications were hindered by concomitant supplementation with ASTA despite ASTA-related antioxidant protection was mainly observed in plasma. Although it is clear that ASTA properly crosses the brain-blood barrier, our data also address a possible indirect role of ASTA in restoring basal oxidative conditions in anterior forebrain of animals: by improving GSH-based antioxidant capacity of plasma. Preliminary anxiolytic tests performed in the elevated plus maze are in alignment with our biochemical observations.

Marine carotenoids: biological functions and commercial applications

Carotenoids are the most common pigments in nature and are synthesized by all photosynthetic organisms and fungi. Carotenoids are considered key molecules for life. Light capture, photosynthesis photoprotection, excess light dissipation and quenching of singlet oxygen are among key biological functions of carotenoids relevant for life on earth. Biological properties of carotenoids allow for a wide range of commercial applications. Indeed, recent interest in the carotenoids has been mainly for their nutraceutical properties. A large number of scientific studies have confirmed the benefits of carotenoids to health and their use for this purpose is growing rapidly. In addition, carotenoids have traditionally been used in food and animal feed for their color properties. Carotenoids are also known to improve consumer perception of quality; an example is the addition of carotenoids to fish feed to impart color to farmed salmon.

ROS production in neutrophils from alloxan-induced diabetic rats treated in vivo with astaxanthin

BACKGROUND

Astaxanthin (ASTA) is a carotenoid which has powerful antioxidant, anti-tumor, anti-diabetic, anti-inflammatory and cardioprotective properties. The present study investigated the effect of daily ASTA intake on oxidative stress and the functional properties of neutrophils from alloxan-induced diabetic rats.

METHODS

Neutrophils isolated from ASTA-fed rats (30days, 20mg ASTA/kg of body weight - BW) induced to diabetes by alloxan treatment (i.p. 75mg/BW) were assessed by: production of superoxide and hydrogen peroxide, nitric oxide, basal calcium release, oxidative damage (TBARS and carbonyls content), and activities of major antioxidant enzymes.

RESULTS

Our results show that diabetes promotes a significant oxidative stress in neutrophils. The production of superoxide was significantly increased in neutrophils from diabetic rats and treatment with ASTA was not effective in reducing superoxide levels. At the same time, a reduction in the activity of total superoxide dismutase enzyme was observed, which was not restored after treatment with ASTA. At resting conditions, neutrophils have a higher basal production of hydrogen peroxide, which is enhanced following PMA-stimulation. Treatment with ASTA does not restore values to the basal levels. The indicators of oxidative damage to biomolecules showed that diabetic rats significantly increased the lipid and protein damage, but this change was reversed after treatment with ASTA.

CONCLUSION

Our results show that diabetes condition promotes a marked oxidative stress in neutrophils and treatment with ASTA for 30days at a dose of 20mg/kg of BW partially reverses those deleterious effects.