Astaxanthin ameliorates features of metabolic syndrome in SHR/NDmcr-cp

Astaxanthin obtained from freshwater crustaceans mitigates visceral adiposity by modulating adipose tissue lipogenesis and ameliorates dyslipidemia in high-sucrose diet fed rats

The incidence of overweight and obesity continues to grow at alarming rates around the world. The search for foods with potential benefits in the prevention/treatment of overweight/obesity and related disorders has great relevance. The aim of this study was to evaluate the effect of astaxanthin (ASTX) from freshwater crustaceans (crabs) upon visceral adiposity, adipose tissue lipid metabolism disorders and dyslipidemia present in a Metabolic Syndrome rodent model. Male Wistar rats were fed for 90 days with 1 of 4 experimental diets: a-Reference group (RD) received a standard commercial rodent diet, b- High-sucrose diet (HSD) group received a HSD, c- RD+ASTX group received a standard commercial rodent diet plus ASTX, d- HSD+ASTX group received a HSD plus ASTX. The rats were given orally either ASTX (10 mg/kg body weight/day in sunflower oil) or only sunflower oil. Compared with HSD-fed rats, HSD+ASTX group had lower body weight gain (19%) and both reduced abdominal circumference (5%) and visceral adiposity index (5%). Energy intake was 24% lower at the middle of the experimental period. Epididymal adipocytes size and triglyceride (TG) content was reduced by 14%. Besides, fatty acid synthase, malic enzyme and glucose-6-phosphate dehydrogenase activities in epididymal adipose tissue were 43%, 28% and 38% lower respectively. These changes were accompanied by lower TG (25%) and cholesterol (27%) serum levels, atherogenic index (31%) and reduced Systolic (12%) and Diastolic (15%) blood pressure. The results show that ASTX could be a potential strategy to prevent/attenuate the incidence of metabolic risk factors such as overweight/adiposity and dyslipidemia.

Revolutionizing Diabetes Care: The Role of Marine Bioactive Compounds and Microorganisms

Diabetes is a metabolic condition characterized by high blood glucose levels. Aquatic products like microalgae, bacteria, seagrasses, macroalgae, corals, and sponges have been investigated for potential anti-diabetic properties. We looked at polyphenols, peptides, pigments, and sterols, as well as other bioactive substances found in marine resources, to see if they could help treat or manage diabetes, in addition to describing the several treatment strategies that alter diabetes and its implications, such as inhibition of protein tyrosine phosphatases 1B (PTP1B), α-glucosidase, α-amylase, dipeptidyl peptidase IV (DPP-IV), aldose reductase, lipase, glycogen synthase kinase 3β (GSK-3β), and insulin resistance prevention, promotion of liver antioxidant capacity, natural killer cell stimulant, anti-inflammatory actions, increased AMP-activated protein kinase (AMPK) phosphorylation and sugar and metabolism of the lipid, reducing oxidative stress, and β-pancreatic cell prevention. This study highlights the revolutionary potential of marine bioactive compounds and microorganisms in transforming diabetes care. We believe in a future in which innovative, sustainable, and efficient therapeutic approaches will result in improved quality of life and better outcomes for people with diabetes mellitus by forging a new path for treatment, utilizing the power of the world's oceans, and capitalizing on the symbiotic relationship between humans and the marine ecosystem. This study area offers optimism and promising opportunities for transforming diabetes care.

Unveiling astaxanthin: biotechnological advances, delivery systems and versatile applications in nutraceuticals and cosmetics

Astaxanthin (ASX), "king of carotenoids", is a xanthophyll carotenoid that is characterized by a distinct reddish-orange hue, procured from diverse sources including plants, microalgae, fungi, yeast, and lichens. It exhibits potent antioxidant and anti-ageing properties and has been demonstrated to mitigate ultraviolet-induced cellular and DNA damage, enhance immune system function, and improve cardiovascular diseases. Despite its broad utilization across nutraceutical, cosmetic, aquaculture, and pharmaceutical sectors, the large-scale production and application of ASX are constrained by the limited availability of natural sources, low production yields and stringent production requirements. This review provides a comprehensive analysis of ASX applications, emphasizing its dual roles in cosmetic and nutraceutical fields. It integrates insights into the qualitative differences of ASX from various natural sources and assesses biosynthetic pathways across organisms. Advanced biotechnological strategies for industrial-scale production are explored alongside innovative delivery systems, such as emulsions, films, microcapsules, nanoliposomes, and nanoparticles, designed to enhance ASX's bioavailability and functional efficacy. By unifying perspectives on its nutraceutical and cosmetic applications, this review highlights the challenges and advancements in formulation and commercialization. Prospective research directions for optimizing ASX's production and applications are also discussed, providing a roadmap for its future development.

The Effects of Astaxanthin on Metabolic Syndrome: A Comprehensive Review

Metabolic syndrome (MS) represents a complex cluster of metabolic disorders primarily characterized by obesity, insulin resistance, hyperglycemia, dyslipidemia, hypertension, and hyperuricemia. Diet and functional ingredients play a pivotal role in seeking non-pharmacological strategies to prevent and ameliorate MS. Astaxanthin (AST), a carotenoid found in various marine organisms, exhibits exceptional antioxidant properties and holds great promise as a natural compound that improves MS. This article introduces the basic properties of AST, including its absorptance and metabolic pathways, along with various isomers. Most importantly, we comprehensively review the effects and mechanisms of AST on improving the primary components of MS. These mechanisms primarily involve regulating signal transduction, transport, or metabolic pathways within the body, as well as influencing intestinal microbiota and metabolites, thereby exerting positive effects on metabolism and inhibiting the occurrence of MS. This review emphasizes the potential efficacy of AST in managing MS. However, more studies are needed to confirm the clinical effect of AST on MS and reveal potential molecular mechanisms.

The effect of long term astaxanthin supplementation on the antioxidant status of racing Arabian horses - preliminary study

Astaxanthin due to its strong antioxidant activity is believed to reduce oxidative stress and therefore is considered as feed additive in pathological conditions and also for the athletes. It is promoted by several equine web portals, however, data supporting that concept in horses is limited. Thus, the aim of this study was to evaluate the effect of astaxanthin supplementation on the parameters of oxidative status in 3 years old, racing Arabian horses during long term observation and the changes related to a single training session of high intensity. Six horses were supplemented with astaxanthin at a dose of 0.52-0.58 mg/kg BW and 7 received no supplementation. Astaxanthin supplementation resulted in the increase in total antioxidant status by 31.5%, accompanied by decreases in the amount of total thiobarbituric acid-reactive substances -TBARS and glutathione reductases - GR values by 34.5% and 45.4%, respectively, after 1 month and this effect persisted until the end of the observation. After individual training session the activities of glutathione peroxidases and GR were lower by 69% and 46%, respectively, and TBARS lower by 38% in supplemented horses. These results directly confirmed the beneficial effects of astaxanthin supplementation on the antioxidant status of race horses. Astaxanthin partially counterbalance the training-related oxidative stress, save the horse natural antioxidant defense, and shift the redox status towards a more reducing environment. At the same time, exercise-induced reactive oxygen species production at certain level was maintained and so that contributed to training progress.

Comparative Pharmacokinetic Study of Standard Astaxanthin and its Micellar Formulation in Healthy Male Volunteers

BACKGROUND AND OBJECTIVE

Astaxanthin is a naturally occurring carotenoid with high anti-oxidant properties, but it is a very lipophilic compound with low oral bioavailability. This study was conducted to compare the pharmacokinetic parameters of a novel astaxanthin preparation based on micellar solubilization technology, NovaSOL® 400-mg capsules (Test product), and those of astaxanthin 400-mg capsules (reference product), after single oral dose administration to healthy male adults.

METHODS

A single oral dose (400 mg equivalent to 8 mg astaxanthin) of test and reference astaxanthin were administered with 240 mL of water to 12 volunteers according to crossover design, in two phases, with a washout period of 1 week in between. Blood samples were collected at hourly intervals for the first 12 h, then at 24.0, 48.0, and 72.0 h after administration. Aliquots of plasma were centrifuged and the clear supernatant was injected into the high performance liquid chromatography-diode array detection (HPLC-DAD) system. Plasma concentration of astaxanthin versus time profiles were constructed, and the primary pharmacokinetic parameters, maximum concentration (Cmax), area under concentration time curve from time of administration (0) to time (t) [AUC0-t] or to infinity ∞, [AUC0-∞],  half-life (T½) and time to reach Cmax (Tmax) were calculated.

RESULTS

The test micellar astaxanthin reached a Cmax of 7.21 µg/ml after 3.67 h compared to only 3.86 µg/ml after 8.5 h for the reference native astaxanthin.

CONCLUSION

Micellar formulation of astaxanthin is capable of producing a high concentration of astaxanthin in plasma in a shorter time, thereby expected to provide faster potential therapeutic efficacy.

Astaxanthin Supplementation as a Potential Strategy for Enhancing Mitochondrial Adaptations in the Endurance Athlete: An Invited Review

Astaxanthin, a potent antioxidant found in marine organisms such as microalgae and krill, may offer ergogenic benefits to endurance athletes. Originally used in fish feed, astaxanthin has shown a greater ability to mitigate various reactive oxygen species and maintain the structural integrity of mitochondria compared to other exogenous antioxidants. More recent work has shown that astaxanthin may improve: (1) cycling time trial performance, (2) cardiorespiratory measures such as submaximal heart rate during running or cycling, (3) recovery from delayed-onset muscle soreness, and (4) endogenous antioxidant capacity such as whole blood glutathione within trained populations. In this review, the history of astaxanthin and its chemical structure are first outlined before briefly describing the various adaptations (e.g., mitochondrial biogenesis, enhanced endogenous antioxidant capacity, etc.) which take place specifically at the mitochondrial level as a result of chronic endurance training. The review then concludes with the potential additive effects that astaxanthin may offer in conjunction with endurance training for the endurance athlete and offers some suggested practical recommendations for athletes and coaches interested in supplementing with astaxanthin.

Effects of shrimp oil on cardio-metabolic risk factors in children and adolescents

Background: Antioxidants have beneficial effects on health. Shrimp oil has Astaxanthin and omega 3 that act as powerful antioxidants and might have anti-inflammatory effects on cardiovascular diseases. This study aims to investigate the effects of shrimp oil supplementation on cardio-metabolic risk factors in overweight and obese children and adolescents. Methods: This randomized, triple-blind, placebo-controlled clinical trial was conducted on 64 overweight and obese participants with 10-18 years of age. They were randomly assigned to receive either 500 mg shrimp oil or identical placebo that contained medium-chain triglycerides once per day for eight weeks. Dietary intake was obtained using food record questionnaire for three days at baseline and at the end of the study. Fasting blood samples were obtained at baseline and after eight weeks of intervention. Results: Overall, 53 participants completed the study; 30 subjects received shrimp oil and 23 subjects received placebo. There were no significant effects of shrimp oil on total cholesterol, triglyceride, HDL-C, LDL-C and blood pressure compared with the placebo group (p>0.05). Shrimp oil had no significant effects on body mass index, waist circumference and hip circumference compared with the placebo group (p>0.05). Conclusions: Supplementation with shrimp oil had no significant effects on improving the anthropometric measures and cardio-metabolic risk factors. Future clinical trials are needed to investigate the beneficial effects of higher doses of shrimp oil on cardio-metabolic risk factors in the pediatric age groups.

Effects of lipid extract from blue mussel (Mytilus edulis) on gut microbiota, and its relationship with glycemic traits in type 2 diabetes mellitus patients: a double-blind randomized controlled trial

Studies have shown that blue mussel lipid extract (BMLE) can improve the glycemic traits, inflammatory cytokines, and lipid profile of patients with type 2 diabetes mellitus (T2DM) in China. Gut microbiota is closely related to T2DM. This study aims to explore whether BMLE can improve the glycemic status of T2DM patients by regulating gut microbiota in a 60-day double-blind randomized controlled trial. A total of 133 T2DM subjects were randomized into BMLE (n = 44), fish oil (FO) (n = 44), and corn oil (CO) (n = 45) groups. The participants were asked to take two corresponding oil capsules (0.8 g per capsule each) every day. The faecal microbiota, glycemic traits, and other cardiometabolic factors were analyzed at baseline and endpoint. The α diversity estimators of Ace and Chao1 decreased significantly in all three groups, but there was no significant difference between the groups. Eight bacteria decreased significantly in the BMLE group but not in the FO and CO groups: unclassified_Clostridia_UCG_014, unclassified_Bacteroidia, Erysipelotrichaceae, and uncultured_Ruminococcaceae_bacterium at the family level and unclassified_Bacteroidia, uncultured_Ruminococcaceae_bacterium, unclassified_Clostridia_UCG_014, and Turicibacter at genus level. In the BMLE group, the change in the relative abundance of Erysipelotrichaceae was positively correlated with the changes in the homeostatic model assessment of insulin resistance (HOMA-IR) (r = 0.454, p < 0.01) and fasting insulin (r = 0.414, p < 0.01). The change in the relative abundance of Turicibacter was positively correlated with the changes in HOMA-IR (r = 0.431, p < 0.01), fasting insulin (r = 0.414, p < 0.01), total cholesterol (TC) (r = 0.358, p < 0.05), and triacylglycerol (TG) (r = 0.393 p = 0.013). In conclusion, BMLE might improve glycemic traits by modulating gut microbiota in T2DM patients.

More Than Pigments: The Potential of Astaxanthin and Bacterioruberin-Based Nanomedicines

Carotenoids are natural products regulated by the food sector, currently used as feed dyes and as antioxidants in dietary supplements and composing functional foods for human consumption. Of the nearly one thousand carotenoids described to date, only retinoids, derived from beta carotene, have the status of a drug and are regulated by the pharmaceutical sector. In this review, we address a novel field: the transformation of xanthophylls, particularly the highly marketed astaxanthin and the practically unknown bacterioruberin, in therapeutic agents by altering their pharmacokinetics, biodistribution, and pharmacodynamics through their formulation as nanomedicines. The antioxidant activity of xanthophylls is mediated by routes different from those of the classical oral anti-inflammatory drugs such as corticosteroids and non-steroidal anti-inflammatory drugs (NSAIDs): remarkably, xanthophylls lack therapeutic activity but also lack toxicity. Formulated as nanomedicines, xanthophylls gain therapeutic activity by mechanisms other than increased bioavailability. Loaded into ad hoc tailored nanoparticles to protect their structure throughout storage and during gastrointestinal transit or skin penetration, xanthophylls can be targeted and delivered to selected inflamed cell groups, achieving a massive intracellular concentration after endocytosis of small doses of formulation. Most first reports showing the activities of oral and topical anti-inflammatory xanthophyll-based nanomedicines against chronic diseases such as inflammatory bowel disease, psoriasis, atopic dermatitis, and dry eye disease emerged between 2020 and 2023. Here we discuss in detail their preclinical performance, mostly targeted vesicular and polymeric nanoparticles, on cellular models and in vivo. The results, although preliminary, are auspicious enough to speculate upon their potential use for oral or topical administration in the treatment of chronic inflammatory diseases.

Marine Natural and Nature-Inspired Compounds Targeting Peroxisome Proliferator Activated Receptors (PPARs)

Peroxisome proliferator-activated receptors α, γ and β/δ (PPARα, PPARγ, and PPARβ/δ) are a family of ligand-activated transcriptional factors belonging to the superfamily of nuclear receptors regulating the expression of genes involved in lipid and carbohydrate metabolism, energy homeostasis, inflammation, and the immune response. For this reason, they represent attractive targets for the treatment of a variety of metabolic diseases and, more recently, for neurodegenerative disorders due to their emerging neuroprotective effects. The degree of activation, from partial to full, along with the selectivity toward the different isoforms, greatly affect the therapeutic efficacy and the safety profile of PPAR agonists. Thus, there is a high interest toward novel scaffolds with proper combinations of activity and selectivity. This review intends to provide an overview of the discovery, optimization, and structure-activity relationship studies on PPAR modulators from marine sources, along with the structural and computational studies that led to their identification and/or elucidation, and rationalization of their mechanisms of action.

More Than an Antioxidant: Role of Dietary Astaxanthin on Lipid and Glucose Metabolism in the Liver of Rainbow Trout (Oncorhynchus mykiss)

This study investigated the influence of dietary astaxanthin (AX) on glucose and lipid metabolism in rainbow trout liver. Two iso-nitrogenous and iso-lipidic diets were tested for 12 weeks in rainbow trout with an initial mean weight of 309 g. The S-ASTA diet was supplemented with 100 mg of synthetic AX per kg of feed, whereas the control diet (CTRL) had no AX. Fish fed the S-ASTA diet displayed lower neutral and higher polar lipids in the liver, associated with smaller hepatocytes and lower cytoplasm vacuolization. Dietary AX upregulated adipose triglyceride lipase (atgl), hormone-sensitive lipase (hsl2) and 1,2-diacylglycerol choline phosphotransferase (chpt), and downregulated diacylglycerol acyltransferase (dgat2), suggesting the AX's role in triacylglycerol (TAG) turnover and phospholipid (PL) synthesis. Dietary AX may also affect beta-oxidation with the upregulation of carnitine palmitoyltransferase 1 (cpt1α2). Although hepatic cholesterol levels were not affected, dietary AX increased gene expression of sterol regulatory element-binding protein 2 (srebp2). Dietary AX upregulated the expression of 6-phosphogluconate dehydrogenase (6pgdh) and downregulated pyruvate kinase (pkl). Overall, results suggest that dietary AX modulates the oxidative phase of the pentose phosphate pathway and the last step of glycolysis, affecting TAG turnover, β-oxidation, PL and cholesterol synthesis in rainbow trout liver.

The landscape of potential health benefits of carotenoids as natural supportive therapeutics in protecting against Coronavirus infection

The Coronavirus Disease-2019 (COVID-19) pandemic urges researching possibilities for prevention and management of the effects of the virus. Carotenoids are natural phytochemicals of anti-oxidant, anti-inflammatory and immunomodulatory properties and may exert potential in aiding in combatting the pandemic. This review presents the direct and indirect evidence of the health benefits of carotenoids and derivatives based on in vitro and in vivo studies, human clinical trials and epidemiological studies and proposes possible mechanisms of action via which carotenoids may have the capacity to protect against COVID-19 effects. The current evidence provides a rationale for considering carotenoids as natural supportive nutrients via antioxidant activities, including scavenging lipid-soluble radicals, reducing hypoxia-associated superoxide by activating antioxidant enzymes, or suppressing enzymes that produce reactive oxygen species (ROS). Carotenoids may regulate COVID-19 induced over-production of pro-inflammatory cytokines, chemokines, pro-inflammatory enzymes and adhesion molecules by nuclear factor kappa B (NF-κB), renin-angiotensin-aldosterone system (RAS) and interleukins-6- Janus kinase-signal transducer and activator of transcription (IL-6-JAK/STAT) pathways and suppress the polarization of pro-inflammatory M1 macrophage. Moreover, carotenoids may modulate the peroxisome proliferator-activated receptors γ by acting as agonists to alleviate COVID-19 symptoms. They also may potentially block the cellular receptor of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), human angiotensin-converting enzyme 2 (ACE2). These activities may reduce the severity of COVID-19 and flu-like diseases. Thus, carotenoid supplementation may aid in combatting the pandemic, as well as seasonal flu. However, further in vitro, in vivo and in particular long-term clinical trials in COVID-19 patients are needed to evaluate this hypothesis.

Nutraceutical Prevention of Diabetic Complications—Focus on Dicarbonyl and Oxidative Stress

Oxidative and dicarbonyl stress, driven by excess accumulation of glycolytic intermediates in cells that are highly permeable to glucose in the absence of effective insulin activity, appear to be the chief mediators of the complications of diabetes. The most pathogenically significant dicarbonyl stress reflects spontaneous dephosphorylation of glycolytic triose phosphates, giving rise to highly reactive methylglyoxal. This compound can be converted to harmless lactate by the sequential activity of glyoxalase I and II, employing glutathione as a catalyst. The transcription of glyoxalase I, rate-limiting for this process, is promoted by Nrf2, which can be activated by nutraceutical phase 2 inducers such as lipoic acid and sulforaphane. In cells exposed to hyperglycemia, glycine somehow up-regulates Nrf2 activity. Zinc can likewise promote glyoxalase I transcription, via activation of the metal-responsive transcription factor (MTF) that binds to the glyoxalase promoter. Induction of glyoxalase I and metallothionein may explain the protective impact of zinc in rodent models of diabetic complications. With respect to the contribution of oxidative stress to diabetic complications, promoters of mitophagy and mitochondrial biogenesis, UCP2 inducers, inhibitors of NAPDH oxidase, recouplers of eNOS, glutathione precursors, membrane oxidant scavengers, Nrf2 activators, and correction of diabetic thiamine deficiency should help to quell this.

Astaxanthin Carotenoid Modulates Oxidative Stress in Adipose-Derived Stromal Cells Isolated from Equine Metabolic Syndrome Affected Horses by Targeting Mitochondrial Biogenesis

Astaxanthin is gaining recognition as a natural bioactive component. This study aimed to test whether astaxanthin could protect adipose-derived stromal stem cells (ASCs) from apoptosis, mitochondrial dysfunction and oxidative stress. Phaffia rhodozyma was used to extract astaxanthin, whose biocompatibility was tested after 24, 48 and 72 h of incubation with the cells; no harmful impact was found. ASCs were treated with optimal concentrations of astaxanthin. Several parameters were examined: cell viability, apoptosis, reactive oxygen levels, mitochondrial dynamics and metabolism, superoxide dismutase activity, and astaxanthin’s antioxidant capacity. A RT PCR analysis was performed after each test. The astaxanthin treatment significantly reduced apoptosis by modifying the normalized caspase activity of pro-apoptotic pathways (p21, p53, and Bax). Furthermore, by regulating the expression of related master factors SOD1, SOD2, PARKIN, PINK 1, and MFN 1, astaxanthin alleviated the oxidative stress and mitochondrial dynamics failure caused by EMS. Astaxanthin restored mitochondrial oxidative phosphorylation by stimulating markers associated with the OXPHOS machinery: COX4I1, COX4I2, UQCRC2, NDUFA9, and TFAM. Our results suggest that astaxanthin has the potential to open new possibilities for potential bio-drugs to control and suppress oxidative stress, thereby improving the overall metabolic status of equine ASCs suffering from metabolic syndrome.

Pharmaceutical and nutraceutical potential of natural bioactive pigment: astaxanthin

Astaxanthin (3,3'-dihydroxy-β,β-carotene-4,4'-dione) is an orange-red, lipophilic keto-carotenoid pigment. It is majorly found in marine ecosystems particularly in aquatic animals such as salmon, shrimp, trout, krill, crayfish, and so on. It is also synthesized in microalgae Heamatococcus pluvialis, Chlorococcum, Chlorella zofingiensis, red yeast Phaffia rhodozyma and bacterium Paracoccus carotinifaciens. Some aquatic and terrestrial creatures regarded as a primary and secondary sources of the astaxanthin producing and accumulating it through their metabolic pathways. Astaxanthin is the powerful antioxidant, nutritional supplement as well as promising therapeutic compound, observed to have activities against different ravaging diseases and disorders. Researchers have reported remarkable bioactivities of astaxanthin against major non-communicable chronic diseases such as cardiovascular diseases, cancer, diabetes, neurodegenerative, and immune disorders. The current review discusses some structural aspects of astaxanthin. It further elaborates its multiple potencies such as antioxidant, anti-inflammatory, anti-proliferative, anti-cancer, anti-obese, anti-diabetic, anti-ageing, anti-TB, anti-viral, anti-COVID 19, neuro-protective, nephro-protective, and fertility-enhancing properties. These potencies make it a more precious entity in the preventions as well as treatments of prevalent systematic diseases and/or disorders. Also, the review is acknowledging and documenting its powerful bioactivities in relation with the pharmaceutical as well as nutraceutical applicability.

Astaxanthin Enhances Gingival Wound Healing following High Glucose-Induced Oxidative Stress

Fibroblasts of the gingiva play a key role in oral wound healing in diabetes. In this study, effects of astaxanthin (ASTX), a xanthophyll carotenoid, were tested on gingival fibroblasts in a wound healing assay in vitro. The aim of this study was to determine whether ASTX can recover delayed wound healing or not when oxidative stress is elevated by high glucose exposure. For this purpose, human gingival fibroblasts were incubated with or without ASTX following exposure to systemic doses of low glucose (LG) and high glucose (HG) in culture media (5- and 25-, 50 mM D-glucose in DMEM Ham's F12) following 24 hours of incubation. Levels of ROS (Reactive oxygen species) were determined for each experimental group by confocal microscopy. Cell proliferation and viability were assessed by an automated cell counter with trypan blue assay. Wound healing assay was designed in 60 mm petri dishes. Cells were exposed to 5-, 25-, and 50 mM glucose for 24 hours, and a straight line free of cells was created upon full confluency. 100 μM ASTX was added to the recovery group, simultaneously. Cells were monitored with JuLI^Ⓡ-Br Cell History Recorder. ROS levels were significantly increased with increasing glucose levels, while cell proliferation and viability demonstrated a negative correlation with increasing oxidative stress. ROS levels significantly decreased in the 100 μM ASTX-treated group compared to the gingival fibroblasts treated with 50 mM HG medium-only, as well as growth rate and viability. Wound healing was delayed in a dose-dependent manner following high glucose exposure, while ASTX treatment recovered wounded area by 1.16-fold in the 50 mM HG group. Our results demonstrated that ASTX enhances gingival wound healing through its antioxidative properties following high glucose induced oxidative stress. Therefore, ASTX can be suggested as a promising candidate to maintain oral health in chronic wounds of the oral tissues related to diabetes.

Improved intestinal absorption and oral bioavailability of astaxanthin using poly (ethylene glycol)-graft-chitosan nanoparticles: preparation, in vitro evaluation, and pharmacokinetics in rats

BACKGROUND

Astaxanthin (ASTA) is a kind of food-derived active ingredient (FDAI) with antioxidant and antidiabetic functions. It is nontoxic but its poor solubility and low bioavailability hinder its application in the food industry. In this study, a novel carrier, polyethylene glycol-grafted chitosan (PEG-g-CS) was applied to enhance the bioavailability of astaxanthin. It encapsulated astaxanthin completely by solvent evaporation to manufacture astaxanthin using poly (ethylene glycol)-graft-chitosan nanoparticles (ASTA-PEG-g-CS) nanoparticles to improve absorption.

RESULTS

The ASTA-PEG-g-CS nanoparticles were spherical, with a particle size below 200 nm and a ζ potential of about -26 mV. Polyethylene glycol-grafted chitosan can encapsulate astaxanthin well, and the encapsulated astaxanthin was released rapidly - in 15 min in an in vitro release study. In a rat single-pass intestinal perfusion study, a low concentration of ASTA-PEG-g-CS nanoparticle (0.2 μg mL^-1 ) was better absorbed in the intestine. In particular, the jejunum could absorb most astaxanthin without a change in the concentration. An in vivo release study also demonstrated that ASTA-PEG-g-CS nanoparticles enhanced oral bioavailability significantly.

CONCLUSION

This novel carrier, PEG-g-CS, provided a simple way to encapsulate food, which improved the bioavailability of hydrophobic ingredients. © 2021 Society of Chemical Industry.

Astaxanthin as a Novel Mitochondrial Regulator: A New Aspect of Carotenoids, beyond Antioxidants

Astaxanthin is a member of the carotenoid family that is found abundantly in marine organisms, and has been gaining attention in recent years due to its varied biological/physiological activities. It has been reported that astaxanthin functions both as a pigment, and as an antioxidant with superior free radical quenching capacity. We recently reported that astaxanthin modulated mitochondrial functions by a novel mechanism independent of its antioxidant function. In this paper, we review astaxanthin’s well-known antioxidant activity, and expand on astaxanthin’s lesser-known molecular targets, and its role in mitochondrial energy metabolism.

Astaxanthin Ameliorates high-fat diet-induced cardiac damage and fibrosis by upregulating and activating SIRT1

This study evaluated the protective effect of astaxanthin (ASX) against high-fat diet (HFD)-induced cardiac damage and fibrosis in rats and examined if the mechanism of protection involves modulating SIRT1. Rat were divided into 5 groups (n = 10/group) as: 1) control: fed normal diet (3.82 kcal/g), 2) control + ASX (200 mg/kg/orally), 3) HFD: fed HFD (4.7 kcal/g), 4) HFD + ASX (200 mg/kg/orally), and HFD + ASX + EX-527 (1 mg/kg/i.p) (a selective SIRT1 inhibitor). All treatments were conducted for 14 weeks. Administration of ASX reduced cardiomyocyte damage, inhibited inflammatory cell infiltration, preserved cardiac fibers structure, prevented collagen deposition and protein levels of TGF-β 1 in the left ventricles (LVs) of HFD-fed rats. In the LVs of both the control and HFD-fed rat, ASX significantly reduced levels of reactive oxygen species (ROS), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and p-smad2/3 (Lys19) but increased the levels of glutathione (GSH), catalase, and manganese superoxide dismutase (MnSOD). Concomitantly, it increased the nuclear activity of Nrf2 and reduced that of NF-κB p65. Furthermore, administration of ASX to both the control and HFD-fed rats increased total and nuclear levels of SIRT1, stimulated the nuclear activity of SIRT1, and reduced the acetylation of Nrf2, NF-κB p65, and Smad3. All these cardiac beneficial effects of ASX in the HFD-fed rats were abolished by co-administration of EX-527. In conclusion, ASX stimulates antioxidants and inhibits markers of inflammation under basal and HFD conditions. The mechanism of protection involves, at least, activation SIRT1 signaling.

Astaxanthin, a Marine Carotenoid, Maintains the Tolerance and Integrity of Adipose Tissue and Contributes to Its Healthy Functions

Recently, obesity-induced insulin resistance, type 2 diabetes, and cardiovascular disease have become major social problems. We have previously shown that Astaxanthin (AX), which is a natural antioxidant, significantly ameliorates obesity-induced glucose intolerance and insulin resistance. It is well known that AX is a strong lipophilic antioxidant and has been shown to be beneficial for acute inflammation. However, the actual effects of AX on chronic inflammation in adipose tissue (AT) remain unclear. To observe the effects of AX on AT functions in obese mice, we fed six-week-old male C57BL/6J on high-fat-diet (HFD) supplemented with or without 0.02% of AX for 24 weeks. We determined the effect of AX at 10 and 24 weeks of HFD with or without AX on various parameters including insulin sensitivity, glucose tolerance, inflammation, and mitochondrial function in AT. We found that AX significantly reduced oxidative stress and macrophage infiltration into AT, as well as maintaining healthy AT function. Furthermore, AX prevented pathological AT remodeling probably caused by hypoxia in AT. Collectively, AX treatment exerted anti-inflammatory effects via its antioxidant activity in AT, maintained the vascular structure of AT and preserved the stem cells and progenitor's niche, and enhanced anti-inflammatory hypoxia induction factor-2α-dominant hypoxic response. Through these mechanisms of action, it prevented the pathological remodeling of AT and maintained its integrity.

Multi-Mechanistic Antidiabetic Potential of Astaxanthin: An Update on Preclinical and Clinical Evidence

Diabetes mellitus (DM) is a cluster of physiological dysfunctions typified by persistent hyperglycemia. Diet plays a paramount role in human health, and regular consumption of a fruit- and vegetable-rich diet can delay or prevent DM and its associated complications. The promising effect of fruits and vegetables could be partly attributed to their antioxidant constituents, including carotenoids. Carotenoids are natural antioxidants that occur in many vegetables, fruits, microalgae, and other natural sources. Astaxanthin is a xanthophyll carotenoid predominantly present in microalgae and some red-colored marine organisms. It is currently marketed as a health supplement and is well-known for its antioxidant capacity. Accumulating evidence indicates that astaxanthin exerts its beneficial effects against DM by acting on various molecular targets and signaling pathways in multiple organs/tissues. Astaxanthin can lower blood glucose levels by preserving β-cell function, improving insulin resistance (IR), and increasing insulin secretion. This manuscript summarizes the connection between glucose homeostasis, oxidative stress, and DM. This is followed by a review of recent studies on astaxanthin's pharmacological effects against IR, microvascular (diabetic retinopathy, diabetic nephropathy, and neurological damage), and macrovascular DM complications emphasizing the cellular and molecular mechanisms involved. A few lines of clinical evidence supporting its antidiabetic potential are also highlighted.

Astaxanthin attenuates hepatic steatosis in high-fat diet-fed rats by suppressing microRNA-21 via transactivation of nuclear factor erythroid 2-related factor 2

This study examined whether astaxanthin (ASX) could alleviate hepatic steatosis in rats fed a high-fat diet (HFD) by modulating the nuclear factor erythroid 2-related factor 2 (Nrf2)/miR-21 axis. Rats (n = 8/group) were fed either a standard diet (3.8 kcal/g; 10% fat) or HFD (4.6 kcal/g; 40% fat) and treated orally with either the vehicle or ASX (6 mg/kg) daily for 8 days. Another group was fed HFD and treated with ASX and brusatol (an Nrf2 inhibitor) (2 mg/kg/twice per week/i.p.). ASX prevented the gain in body and liver weights and attenuated hepatic lipid accumulation in HFD-fed rats. In the control and HFD-fed rats, ASX did not affect food intake, serum free fatty acid (FFA) content, and glucose and insulin levels and tolerance. However, serum triglyceride (TG), cholesterol, and low-density lipoprotein-cholesterol levels; hepatic levels of TGs and FFAs; and hepatic levels of Srebp1, Srebp2, HMGCR, and fatty acid synthase mRNAs and miR-21 were reduced and the mRNA levels of Pparα were significantly increased in both the groups. These effects were associated with a reduction in the hepatic levels of reactive oxygen species, malondialdehyde, tumor necrosis factor-α, and interlukin-6 as well as an increase in superoxide dismutase levels, total glutathione content, and nuclear levels and activity of Nrf2. miR-21 levels were strongly correlated with the nuclear activity of Nrf2. Brusatol completely reversed the effects of ASX. In conclusion, ASX prevents hepatic steatosis mainly by transactivating Nrf2 and is associated with the suppression of miR-21 and Srebp1/2 and upregulation of Pparα expression.

Astaxanthin Prevents Diet-Induced NASH Progression by Shaping Intrahepatic Immunity

Dietary change leads to a precipitous increase in non-alcoholic fatty liver disease (NAFLD) from simple steatosis to the advanced form of non-alcoholic steatohepatitis (NASH), affecting approximately 25% of the global population. Although significant efforts greatly advance progress in clarifying the pathogenesis of NAFLD and identifying therapeutic targets, no therapeutic agent has been approved. Astaxanthin (ASTN), a natural antioxidant product, exerts an anti-inflammation and anti-fibrotic effect in mice induced with carbon tetrachloride (CCl4) and bile duct ligation (BDL); thus, we proposed to further investigate the potential effect of ASTN on a diet-induced mouse NASH and liver fibrosis, as well as the underlying cellular and molecular mechanisms. By treating pre-development of NASH in mice induced with a choline-deficient, L-amino acid-defined, high-fat diet (CDAHFD), we have demonstrated that oral administration ASTN preventively ameliorated NASH development and liver fibrosis by modulating the hepatic immune response, liver inflammation, and oxidative stress. Specifically, ASTN treatment led to the reduction in liver infiltration of monocyte-derived macrophages, hepatic stellate cell (HSC) activation, oxidative stress response, and hepatocyte death, accompanied by the decreased hepatic gene expression of proinflammatory cytokines such as TNF-α, TGF-β1, and IL-1β. In vitro studies also demonstrated that ASTN significantly inhibited the expression of proinflammatory cytokines and chemokine CCL2 in macrophages in response to lipopolysaccharide (LPS) stimulation. Overall, in vivo and in vitro studies suggest that ASTN functions as a promising therapeutic agent to suppress NASH and liver fibrosis via modulating intrahepatic immunity.

Advances in Technologies for Highly Active Omega-3 Fatty Acids from Krill Oil: Clinical Applications

Euphausia superba, commonly known as krill, is a small marine crustacean from the Antarctic Ocean that plays an important role in the marine ecosystem, serving as feed for most fish. It is a known source of highly bioavailable omega-3 polyunsaturated fatty acids (eicosapentaenoic acid and docosahexaenoic acid). In preclinical studies, krill oil showed metabolic, anti-inflammatory, neuroprotective and chemo preventive effects, while in clinical trials it showed significant metabolic, vascular and ergogenic actions. Solvent extraction is the most conventional method to obtain krill oil. However, different solvents must be used to extract all lipids from krill because of the diversity of the polarities of the lipid compounds in the biomass. This review aims to provide an overview of the chemical composition, bioavailability and bioaccessibility of krill oil, as well as the mechanisms of action, classic and non-conventional extraction techniques, health benefits and current applications of this marine crustacean.

Anti-diabetic effects of astaxanthin on an STZ-induced diabetic model in rats

Type 2 diabetes mellitus (T2DM), which is characterized by insulin resistance and relative insulin insufficiency, has become the most common chronic metabolic disease threatening global health. The preferred therapies for T2DM include lifestyle interventions and the use of anti-diabetic drugs. However, considering their adverse reactions, it is important to find a low-toxicity and effective functional food or drug for diabetes prevention and treatment. Astaxanthin is a potent antioxidant carotenoid found in marine organisms has been reported to prevent diet-induced insulin resistance and hepatic steatosis. To investigate the anti-diabetic effects of astaxanthin, male Wistar rats were fed a high-energy diet for 4 weeks, followed by a low dose streptozotocin (STZ) injection to induce the diabetes model, and the rats were then fed an astaxanthin-containing diet for another 3 weeks. Astaxanthin significantly decreased blood glucose and total cholesterol (TC) levels, and increased blood levels of high density lipoprotein cholesterol (HDL-C) in STZ-induced diabetic rats in a dose dependent manner. These results were associated with increased expression of insulin sensitivity related genes (adiponectin, adipoR1, and adipoR2) in vivo, thereby attenuating STZ-induced diabetes. In addition, we also compared the anti-diabetic effects of astaxanthin and monacolin K, which has been reported to downregulate hyperlipidemia and hyperglycemia. The results revealed that astaxanthin and monacolin K showed similar anti-diabetic effects in STZ-induced diabetic rats. Therefore, astaxanthin may be developed as an anti-diabetic agent in the future.

Effect of Astaxanthin on the Expression and Activity of Aquaporin-3 in Skin in an In-Vitro Study

Astaxanthin (3,3′-dihydroxy-β,β-carotene-4,4′-dione) is a red lipophilic pigment with strong antioxidant action. Oral or topical administration of astaxanthin has been reported to improve skin function, including increasing skin moisture. In this study, we examined the mechanism by which astaxanthin improves skin function by focusing on the water channel aquaporin-3 (AQP3), which plays important roles in maintaining skin moisture and function. When astaxanthin was added to PHK16-0b or HaCaT cells, the mRNA expression level of AQP3 increased significantly in a concentration-dependent manner in both cell lines. The AQP3 protein expression level was also confirmed to increase when astaxanthin was added to HaCaT cells. Similarly, when astaxanthin was added to 3D human epidermis model EpiSkin, AQP3 expression increased. Furthermore, when glycerol and astaxanthin were simultaneously added to EpiSkin, glycerol permeability increased significantly compared with that observed for the addition of glycerol alone. We demonstrated that astaxanthin increases AQP3 expression in the skin and enhances AQP3 activity. This result suggests that the increased AQP3 expression in the skin is associated with the increase in skin moisture by astaxanthin. Thus, we consider astaxanthin useful for treating dry skin caused by decreased AQP3 due to factors such as diabetes mellitus and aging.

Impact of Astaxanthin on Diabetes Pathogenesis and Chronic Complications

Oxidative stress (OS) plays a pivotal role in diabetes mellitus (DM) onset, progression, and chronic complications. Hyperglycemia-induced reactive oxygen species (ROS) have been shown to reduce insulin secretion from pancreatic β-cells, to impair insulin sensitivity and signaling in insulin-responsive tissues, and to alter endothelial cells function in both type 1 and type 2 DM. As a powerful antioxidant without side effects, astaxanthin (ASX), a xanthophyll carotenoid, has been suggested to contribute to the prevention and treatment of DM-associated pathologies. ASX reduces inflammation, OS, and apoptosis by regulating different OS pathways though the exact mechanism remains elusive. Based on several studies conducted on type 1 and type 2 DM animal models, orally or parenterally administrated ASX improves insulin resistance and insulin secretion; reduces hyperglycemia; and exerts protective effects against retinopathy, nephropathy, and neuropathy. However, more experimental support is needed to define conditions for its use. Moreover, its efficacy in diabetic patients is poorly explored. In the present review, we aimed to identify the up-to-date biological effects and underlying mechanisms of ASX on the ROS-induced DM-associated metabolic disorders and subsequent complications. The development of an in-depth research to better understand the biological mechanisms involved and to identify the most effective ASX dosage and route of administration is deemed necessary.

Natural constituents from food sources as therapeutic agents for obesity and metabolic diseases targeting adipose tissue inflammation

Adipose tissue, an endocrine and paracrine organ, plays critical roles in the regulation of whole-body metabolic homeostasis. Obesity is accompanied with a chronic low-grade inflammation status in adipose tissue, which disrupts its endocrine function and results in metabolic derangements, such as type 2 diabetes. Dietary bioactive components, such as flavonoids, polyphenols and unsaturated fatty acids from fruits and vegetables, have been widely revealed to alleviate both systemic and adipose tissue inflammation, and improve metabolic disorders. Remarkably, some dietary bioactive components mitigate the inflammatory response in adipocytes, macrophages, and other immune cells, and modulate the crosstalk between adipocytes and macrophages or other immune cells, in adipose tissue. Epidemiological and preclinical studies related to these substances have indicated beneficial effects on adipose tissue inflammation. The main purpose of this review is to provide a comprehensive and up-to-date state of knowledge on dietary components targeting adipose tissue inflammation and their underlying mechanisms. These natural products have great potential to be developed as functional food or lead compounds for treating and/or preventing metabolic disorders.

Astaxanthin stimulates mitochondrial biogenesis in insulin resistant muscle via activation of AMPK pathway

BACKGROUND

Skeletal muscle is mainly responsible for insulin-stimulated glucose disposal. Dysfunction in skeletal muscle metabolism especially during obesity contributes to the insulin resistance. Astaxanthin (AX), a natural antioxidant, has been shown to ameliorate hepatic insulin resistance in obese mice. However, its effects in skeletal muscle are poorly understood. The current study aimed to investigate the molecular target of AX in ameliorating skeletal muscle insulin resistance.

METHODS

We fed 6-week-old male C57BL/6J mice with normal chow (NC) or NC supplemented with AX (NC+AX) and high-fat-diet (HFD) or HFD supplemented with AX for 24 weeks. We determined the effect of AX on various parameters including insulin sensitivity, glucose uptake, inflammation, kinase signaling, gene expression, and mitochondrial function in muscle. We also determined energy metabolism in intact C2C12 cells treated with AX using the Seahorse XFe96 Extracellular Flux Analyzer and assessed the effect of AX on mitochondrial oxidative phosphorylation and mitochondrial biogenesis.

RESULTS

AX-treated HFD mice showed improved metabolic status with significant reduction in blood glucose, serum total triglycerides, and cholesterol (p< 0.05). AX-treated HFD mice also showed improved glucose metabolism by enhancing glucose incorporation into peripheral target tissues, such as the skeletal muscle, rather than by suppressing gluconeogenesis in the liver as shown by hyperinsulinemic-euglycemic clamp study. AX activated AMPK in the skeletal muscle of the HFD mice and upregulated the expressions of transcriptional factors and coactivator, thereby inducing mitochondrial remodeling, including increased mitochondrial oxidative phosphorylation component and free fatty acid metabolism. We also assessed the effects of AX on mitochondrial biogenesis in the siRNA-mediated AMPK-depleted C2C12 cells and showed that the effect of AX was lost in the genetically AMPK-depleted C2C12 cells. Collectively, AX treatment (i) significantly ameliorated insulin resistance and glucose intolerance through regulation of AMPK activation in the muscle, (ii) stimulated mitochondrial biogenesis in the muscle, (iii) enhanced exercise tolerance and exercise-induced fatty acid metabolism, and (iv) exerted antiinflammatory effects via its antioxidant activity in adipose tissue.

CONCLUSIONS

We concluded that AX treatment stimulated mitochondrial biogenesis and significantly ameliorated insulin resistance through activation of AMPK pathway in the skeletal muscle.

Astaxanthin: A Potential Mitochondrial-Targeted Antioxidant Treatment in Diseases and with Aging

Oxidative stress is characterized by an imbalance between prooxidant and antioxidant species, leading to macromolecular damage and disruption of redox signaling and cellular control. It is a hallmark of various diseases including metabolic syndrome, chronic fatigue syndrome, neurodegenerative, cardiovascular, inflammatory, and age-related diseases. Several mitochondrial defects have been considered to contribute to the development of oxidative stress and known as the major mediators of the aging process and subsequent age-associated diseases. Thus, mitochondrial-targeted antioxidants should prevent or slow down these processes and prolong longevity. This is the reason why antioxidant treatments are extensively studied and newer and newer compounds with such an effect appear. Astaxanthin, a xanthophyll carotenoid, is the most abundant carotenoid in marine organisms and is one of the most powerful natural compounds with remarkable antioxidant activity. Here, we summarize its antioxidant targets, effects, and benefits in diseases and with aging.

Storage of Carotenoids in Crustaceans as an Adaptation to Modulate Immunopathology and Optimize Immunological and Life-History Strategies

Why do some invertebrates store so much carotenoids in their tissues? Storage of carotenoids may not simply be passive and dependent on their environmental availability, as storage variation exists at various taxonomic scales, including among individuals within species. While the strong antioxidant and sometimes immune-stimulating properties of carotenoids may be beneficial enough to cause the evolution of features improving their assimilation and storage, they may also have fitness downsides explaining why massive carotenoid storage is not universal. Here, the functional and ecological implications of carotenoid storage for the evolution of invertebrate innate immune defenses are examined, especially in crustaceans, which massively store carotenoids for unclear reasons. Three testable hypotheses about the role of carotenoid storage in immunological (resistance and tolerance) and life-history strategies (with a focus on aging) are proposed, which may ultimately explain the storage of large amounts of these pigments in a context of host-pathogen interactions.

Immune Defenses of a Beneficial Pest: The Mealworm Beetle, Tenebrio molitor

The mealworm beetle, Tenebrio molitor, is currently considered as a pest when infesting stored grains or grain products. However, mealworms are now being promoted as a beneficial insect because their high nutrient content makes them a viable food source and because they are capable of degrading polystyrene and plastic waste. These attributes make T. molitor attractive for mass rearing, which may promote disease transmission within the insect colonies. Disease resistance is of paramount importance for both the control and the culture of mealworms, and several biotic and abiotic environmental factors affect the success of their anti-parasitic defenses, both positively and negatively. After providing a detailed description of T. molitor's anti-parasitic defenses, we review the main biotic and abiotic environmental factors that alter their presentation, and we discuss their implications for the purpose of controlling the development and health of this insect.

Inhibition of PPARγ by Natural Compounds as a Promising Strategy in Obesity and Diabetes

A wide group of natural compounds (flavonoids, stilbenes, neolignans and others) has been identified as Peroxisome Proliferator-Activated Receptor (PPAR) agonists, with a large variety of chemical structure and different activity versus the three PPAR subtypes. These receptors are transcription factors controlling metabolic pathways in the organism, involved in lipid and glucose metabolism, cell differentiation and energy homeostasis. Otherwise, very little is known about natural compounds able to inhibit PPARs. A number of studies demonstrate that PPARγ repression has a beneficial effect in reducing body weight and improving insulin sensitivity, suggesting a potential clinical role in obesity and type 2 diabetes. This review analyzes natural compounds able to repress PPAR activity and their potential use in metabolic disorders.

The comparison of krill oil extracted through ethanol-hexane method and subcritical method

This study aimed to develop a safe method EH (ethanol-hexane) to extract two kinds of krill oil (KO) simultaneously and analyze their composition. Meanwhile, subcritical butane and subcritical butane-dimethyl ether extraction were used to extract KO for analysis comparison. Folch method was used to extract total lipids. When the volume ratio of ethanol to hexane is 4:6, the separation effect of ethanol layer and hexane layer is best. At this condition, the EH method yielded similar amount of lipids (up to 97. 72% of total lipids) with subcritical butane extraction method (97.60%). The recovery rate of ethanol and hexane was 83.6% and 86.86%, respectively. KO in hexane layer and extracted by the subcritical butane method are abundant in astaxanthin (910 and 940 mg/kg respectively), while KO in the ethanol layer had the highest phospholipid (PL) content (47.34%), n-3 polyunsaturated fatty acids (PUFA) content (45.51%), and the lowest fluorine content (11.17 μg/g), making it a potential candidate in the nutraceutical and antioxidant industry.

Effects of astaxanthin on sensory-motor function in a compression model of spinal cord injury: Involvement of ERK and AKT signalling pathway

BACKGROUND

Spinal cord injury (SCI) causes continuous neurological deficits and major sensory-motor impairments. There is no effective treatment to enhance sensory-motor function following SCI. Thus, it is crucial to develop novel therapeutics for this particular patient population. Astaxanthin (AST) is a strong antioxidant, anti-inflammatory and anti-apoptotic agent. In the present study, it was tested in a severe compression SCI model with emphasis on sensory-motor outcomes, signalling pathway, along with other complications.

METHODS

A severe SCI was induced by compression of the rat thoracic spinal cord with an aneurysm clip and treatment with AST or the vehicle was carried out, 30 min after injury. Behavioural tests including open field, von Frey, hot plate and BBB were performed weekly to 28 days post-injury. Rats were assigned to measure blood glucose, weight and auricle temperature. Western blot and histological analysis also were performed at the same time points.

RESULTS

AST decreased mechanical and thermal pain and also improved motor function performance, reduced blood glucose and auricle temperature increases and attenuated weight loss in SCI rats. Western blot analysis showed decreased activation of ERK1/2 and increased activation of AKT following AST treatment. The histology results revealed that AST considerably preserved myelinated white matter and the number of motor neurons following SCI.

CONCLUSION

Taken together, the beneficial effects of AST to improve sensory-motor outcomes, attenuate pathological tissue damage and modulate ERK and AKT signalling pathways following SCI, suggest it as a strong therapeutic agent towards clinical applications.

SIGNIFICANCE

Spinal cord injury (SCI) impairs sensory-motor function and causes complications, which astaxanthin (AST) has the potential to be used as a treatment for. The present study investigates the effects of AST in a compression model of SCI with emphasis on sensory-motor outcomes alongside other complications, histopathological damage and also related signalling pathways.

Effect of astaxanthin-rich extract derived from Paracoccus carotinifaciens on cognitive function in middle-aged and older individuals

This study was conducted to investigate the effect of dietary supplement containing astaxanthin-rich extract derived from Paracoccus carotinifaciens (astaxanthin supplement) on cognitive function of subjects aged 45–64 years. Cognitive functions of 28 subjects orally administered 8 mg astaxanthin/day of astaxanthin supplement for 8 weeks (astaxanthin group) and 26 subjects given a placebo (placebo group) were compared by word memory test, verbal fluency test, and Stroop test. The astaxanthin group experienced significantly larger increase in blood astaxanthin level than the placebo group. However, there were no significant intergroup differences in the results of the tests. A subgroup analysis was performed after dividing subjects into the <55 years old and ≥55 years old age groups. The result of “words recalled after 5 minutes” in word memory test in <55 years old subjects showed significant improvement in the astaxanthin group than in the placebo group, which was not found in ≥55 years old subjects. Our results indicate that people aged 45–54 years may experience improved cognitive function after ingesting astaxanthin supplement for 8 weeks. On the basis of the parameters tested, administration of astaxanthin supplement was not associated with any problems related to safety.

A Review of the Biological Activities of Microalgal Carotenoids and Their Potential Use in Healthcare and Cosmetic Industries

Carotenoids are natural pigments that play pivotal roles in many physiological functions. The characteristics of carotenoids, their effects on health, and the cosmetic benefits of their usage have been under investigation for a long time; however, most reviews on this subject focus on carotenoids obtained from several microalgae, vegetables, fruits, and higher plants. Recently, microalgae have received much attention due to their abilities in producing novel bioactive metabolites, including a wide range of different carotenoids that can provide for health and cosmetic benefits. The main objectives of this review are to provide an updated view of recent work on the health and cosmetic benefits associated with carotenoid use, as well as to provide a list of microalgae that produce different types of carotenoids. This review could provide new insights to researchers on the potential role of carotenoids in improving human health.

Marine carotenoids: Bioactivities and potential benefits to human health

Among natural pigments, carotenoids play important roles in physiological functions. The characteristics of carotenoids and their effects on human health have been reported for a long time, but most studies have focused on carotenoids from vegetables, fruits, and other parts of higher plants. Few reports are available on carotenoids from marine sources, such as seaweeds, microalgae, and marine animals, which have attracted attention in recent decades. Hundreds of carotenoids have been identified and isolated from marine organisms and their beneficial physiological functions, such as anticancer, antiobesity, antidiabetic, anti-inflammatory, and cardioprotective activities have been reported. The purpose of this review is to discuss the literature on the beneficial bioactivities of some of the most abundant marine carotenoids, including fucoxanthin, astaxanthin, cantaxanthin, peridinin, fucoxanthinol, and halocynthiaxanthin.

Microbial diversity and composition in different gut locations of hyperlipidemic mice receiving krill oil

Low-dose (LD, 100 mg kg^-1 day^-1), moderate-dose (MD, 200 mg kg^-1 day^-1), and high-dose (HD, 600 mg kg^-1 day^-1) krill oil treatments have a stepwise, enhanced effect on alleviating hyperlipidemia, and 16S rRNA sequencing of the fecal samples demonstrates that krill oil treatment alters microbial communities. Feces may not represent all microbial communities in the gastrointestinal (GI) tract. Therefore, in this study, the stored ileal and colon samples collected from LD and HD groups were sequenced, and the location-specific modulations of microbial communities were observed after krill oil treatments. The 16S rRNA sequencing of the ileal samples showed that the LD and HD groups have similar patterns between control and high-fat diet (HFD) treatments, and six most abundant genera and 40 operational taxonomic units that respond to krill oil treatment were identified. However, the 16S rRNA sequencing of the colon samples showed that LD krill oil shifts the structure from the HFD to that of the control, whereas the HD group was distributed between the control and HFD groups. The corresponding most abundant genera and responsive OTUs totaled 4 and 45, respectively. In conclusion, different gastrointestinal tract locations contain different microbial communities. These results will help to provide a comprehensive understanding of the role of dietary krill oil in modulating the gut microbiota and alleviating hyperlipidemia.