Antioxidant effect of astaxanthin on phospholipid peroxidation in human erythrocytes

Effects of carotenoid supplementation on glycemic control: a systematic review and meta-analysis of randomized clinical trials

OBJECTIVES

We conducted a systematic review and meta-analysis to assess the effects of carotenoid supplementation on glycemic indices, and the certainty of evidence.

METHODS

A systematic literature search in PubMed, SCOPUS, ISI-Web of Science, and Cochrane Library was conducted from inception up to Jun 17, 2024. Randomized controlled trials (RCTs) investigating the effect of carotenoid supplementation on circulating glycemic parameters were included. Records were excluded when studies reported the effect of co-interventions with other nutrients, did not provide mean differences (MDs) and standard deviations (SD) for outcomes, or administered whole food rather than supplements of carotenoids. Summary mean differences (MDs) and 95% CI between intervention and control groups were estimated using a random-effects model. The risk of bias of the included studies was assessed using the Risk of Bias 2.0 (RoB 2.0) tool.

RESULTS

Overall, 36 publications with 45 estimated effect sizes were included in the meta-analyses. The overall findings showed an improvement in fasting blood glucose (FBG) (MD = -4.54 mg/dl; 95% CI: -5.9, -3.2; n = 45), and hemoglobin A1C (HbA1C) (MD = -0.25% (95% CI: -0.4, -0.11; n = 22) in the intervention group in comparison with the control group. Moreover, in individuals with type 2 diabetes (T2D), interventions with astaxanthin and fucoxanthin led to a reduction in FBG by 4.36 mg/dl (95% CI: -6.13, -2.6; n = 10). The findings also showed that the intervention with crocin reduced FBG levels by 13.5 mg/dl (95% CI: -15.5, -7.8; n = 5), and HbA1C by 0.55% (95% CI: -0.77, -0.34; n = 5) in individuals with T2D. However, the certainty of evidence was very low.

CONCLUSION

Carotenoid's supplementation improved glycemic parameters especially in people with T2D. However. the certainty of evidence was very low, mainly due to small sample size, and indirectness. Therefore, no specific recommendations can be provided at present and well-designed RCTs are required. REGISTRY URL: https://www.crd.york.ac.uk/PROSPERO/ REGISTRY NUMBER: CRD42021285084 REGISTRY AND REGISTRY NUMBER FOR SYSTEMATIC REVIEWS OR META-ANALYSES: PROSPERO ID: CRD42021285084.

Carotenoid Supplementation for Alleviating the Symptoms of Alzheimer's Disease

Alzheimer's disease (AD) is characterized by, among other things, dementia and a decline in cognitive performance. In AD, dementia has neurodegenerative features and starts with mild cognitive impairment (MCI). Research indicates that apoptosis and neuronal loss occur in AD, in which oxidative stress plays an important role. Therefore, reducing oxidative stress with antioxidants is a natural strategy to prevent and slow down the progression of AD. Carotenoids are natural pigments commonly found in fruits and vegetables. They include lipophilic carotenes, such as lycopene, α- and β-carotenes, and more polar xanthophylls, for example, lutein, zeaxanthin, canthaxanthin, and β-cryptoxanthin. Carotenoids can cross the blood-brain barrier (BBB) and scavenge free radicals, especially singlet oxygen, which helps prevent the peroxidation of lipids abundant in the brain. As a result, carotenoids have neuroprotective potential. Numerous in vivo and in vitro studies, as well as randomized controlled trials, have mostly confirmed that carotenoids can help prevent neurodegeneration and alleviate cognitive impairment in AD. While carotenoids have not been officially approved as an AD therapy, they are indicated in the diet recommended for AD, including the consumption of products rich in carotenoids. This review summarizes the latest research findings supporting the potential use of carotenoids in preventing and alleviating AD symptoms. A literature review suggests that a diet rich in carotenoids should be promoted to avoid cognitive decline in AD. One of the goals of the food industry should be to encourage the enrichment of food products with functional substances, such as carotenoids, which may reduce the risk of neurodegenerative diseases.

Effects of Astaxanthin Supplementation on Fatigue, Motor Function and Cognition: A Meta-Analysis of Randomized Controlled Trials

Dietary astaxanthin supplementation has been demonstrated to have many beneficial and health-promoting effects. The purpose of this systematic review and meta-analysis was to assess the effect of astaxanthin supplementation on fatigue, cognition, and exercise efficiency. A total of 11 randomized controlled trials (RCTs) with 346 healthy participants were included. The random effects model and pooled standardized mean difference (SMDs) were used according to Hedge's g for the meta-analysis, and a meta-regression was also conducted. The results of the two existing studies showed a positive trend for astaxanthin in subjective fatigue relief. The effects of astaxanthin supplementation for 8-12 weeks on cognitive accuracy were marginally significant (SMD: .12; 95% CI: -.02-.26) and on reaction time was not significant (SMD: -.08; 95% CI: -.26 to .10). Remarkably, astaxanthin supplementation combined with regular training could enhance the fat oxidation (SMD: 2.56; 95% CI: 1.24-3.89), and significantly improve the physical performance (SMD: .62; 95% CI: .17-1.06). The subgroup analysis further showed significantly greater benefits when performing the aerobic exercises performance (SMD: .45; 95% CI: .13-.76), when the dose was ≥ 20 mg (SMD: .37; 95% CI: .11-.63), and when the supplementation duration was > 12 weeks (SMD: .66; 95% CI: .13-.63). We conclude that astaxanthin supplementation could significantly enhance aerobic exercise efficiency, especially at higher doses and for longer durations. Further studies based on large sample sizes are imperatively warranted.

Astaxanthin and improvement of dementia: A systematic review of current clinical trials

Worldwide, the incidence of neurodegenerative diseases especially dementia is steadily increasing due to the aging population. Abundant research emerges on the probability of combating or preventing the degeneration process, with the most established one being to tackle the existence of oxidative stress and free radicals production due to their nature of aggravating dementia. Astaxanthin, a marine carotenoid, was proven to be a protective agent of cerebral ischemia through many animal model clinical trials. This review summarizes the evidence of Astaxanthin's benefits for cognitive function across clinical trials done in older age. The results are of interest as its supplementation does not exhibit unwanted issues on the consumer based on physical and laboratory examinations. Despite not being supported statistically, however, subjective and objective cognitive amelioration were reported according to the majority of this review's trial subjects. Although there is no clear and direct mechanism for cognitive improvement by Astaxanthin activity in the body systems, the encouragement of Astaxanthin supplementation should be considered as the elderly with dementia may highly benefit from the improved cognitive function.

The effects of astaxanthin supplementation on liver enzyme levels

According to previous studies, astaxanthin exerts various biological effects due to its anti-inflammatory and antioxidant capabilities; however, its effects on liver enzymes have not yet been well elucidated. Therefore, we conducted a meta-analysis to assess astaxanthin's effects on liver enzymes. A systematic literature search was conducted using scientific databases including PubMed, Scopus, Web of Science, the Cochrane databases, and Google Scholar up to February 2023 to find relevant randomized controlled trials (RCTs) examining the effects of astaxanthin supplementation on alanine transaminase (ALT), aspartate transaminase (AST), gamma-glutamyl transferase (GGT), and alkaline phosphatase (ALP). A random-effects model was used for the estimation of the pooled weighted mean difference (WMD). Overall, we included five trials involving 196 subjects. The duration of the intervention was between 4 and 48 weeks, and the dose was between 6 and 12 mg/day. ALT levels increased in the intervention group compared to the control group following astaxanthin supplementation (WMD: 1.92 U/L, 95% CI: 0.16 to 3.68, P=0.03), whereas supplementation with astaxanthin had a non-significant effect on AST (WMD: 0.72 U/L, 95% CI: -0.85 to 2.29, P=0.36), GGT (WMD: 0.48 U/L, 95% CI: -2.71 to 3.67, P=0.76), and ALP levels (WMD: 2.85 U/L, 95% CI: -7.94 to 13.63, P=0.60) compared to the placebo group. Our data showed that astaxanthin supplementation increases ALT concentrations in adults without affecting the levels of other liver enzymes. Further long-term and well-designed RCTs are necessary to assess and confirm these findings.

Recent progress in practical applications of a potential carotenoid astaxanthin in aquaculture industry: a review

Astaxanthin is the main natural C40 carotenoid used worldwide in the aquaculture industry. It normally occurs in red yeast Phaffia rhodozyma and green alga Haematococcus pluvialis and a variety of aquatic sea creatures, such as trout, salmon, and shrimp. Numerous biological functions reported its antioxidant and anti-inflammatory activities since astaxanthin possesses the highest oxygen radical absorbance capacity (ORAC) and is considered to be over 500 more times effective than vitamin E and other carotenoids such as lutein and lycopene. Thus, synthetic and natural sources of astaxanthin have a commanding influence on industry trends, causing a wave in the world nutraceutical market of the encapsulated product. In vitro and in vivo studies have associated astaxanthin's unique molecular features with various health benefits, including immunomodulatory, photoprotective, and antioxidant properties, providing its chemotherapeutic potential for improving stress tolerance, disease resistance, growth performance, survival, and improved egg quality in farmed fish and crustaceans without exhibiting any cytotoxic effects. Moreover, the most evident effect is the pigmentation merit, where astaxanthin is supplemented in formulated diets to ameliorate the variegation of aquatic species and eventually product quality. Hence, carotenoid astaxanthin could be used as a curative supplement for farmed fish, since it is regarded as an ecologically friendly functional feed additive in the aquaculture industry. In this review, the currently available scientific literature regarding the most significant benefits of astaxanthin is discussed, with a particular focus on potential mechanisms of action responsible for its biological activities.

Effect of carotenoid supplementation on blood pressure in adults: a GRADE-assessed systematic review and dose-response meta-analysis of randomized controlled trials

CONTEXT

Hypertension (HTN) is regarded as a serious public health issue throughout the world. High blood pressure (BP) may be improved by carotenoid supplementation; however, randomized controlled trials (RCTs) provide conflicting evidence.

OBJECTIVE

The aim of this study was to evaluate the effects of carotenoid supplementation on BP in RCTs by systematically review and meta-analysis.

DATA SOURCES

A comprehensive literature search was performed in the Scopus, PubMed, and Web of Science databases until October 2023, with no limitation on the date or language of publication.

DATA EXTRACTION

Studies that evaluated the net effects of carotenoids in the form of supplements on BP in adults were selected. Weighted mean differences (WMDs) and 95% confidence intervals (CIs) were calculated on the basis of a fixed or random-effects model. Sensitivity analysis, meta-regression, publication bias, and heterogeneity were assessed using standard methods. Cochrane quality assessments were used to evaluate the included studies' bias risks. Evidence certainty was calculated using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) framework).

DATA ANALYSIS

Reports on a total of 19 RCTs involving 1151 participants were included in this review. Carotenoid supplementation significantly reduced the systolic BP (SBP) (WMD, -2.492 mmHg; 95%CI, -4.52, -0.47; P = 0.016) and diastolic BP (DBP) (WMD, -1.60 mmHg; 95%CI, -2.73, -0.47; P = 0.005). Greater effects were observed in Asian participants, those aged >50 years, nonhealthy participants, and participants with a baseline SBP ≥130 mmHg and DBP ≥80 mmHg, at dose >10 mg. Dose-response analysis showed that carotenoid supplementation decreased SBP and DBP levels at doses of, respectively, 0-25 and 0-20 mg/d. Evidence for all SBP, DBP, and heart rate values was high quality.

CONCLUSIONS

Carotenoid supplementation had a beneficial effect on BP parameters, especially in nonhealthy study participants with high BP baseline levels.

PROSPERO REGISTRATION NO

CRD42023402740.

Lipidomic assessment of the impact of Nannochloropsis oceanica microalga lipid extract on human skin keratinocytes exposed to chronic UVB radiation

Considerable attention has been devoted to investigating the biological activity of microalgal extracts, highlighting their capacity to modulate cellular metabolism. This study aimed to assess the impact of Nannochloropsis oceanica lipid extract on the phospholipid profile of human keratinocytes subjected to UVB radiation. The outcomes revealed that treatment of keratinocytes with the lipid extract from microalgae led to a reduction in sphingomyelin (SM) levels, with a more pronounced effect observed in UVB-irradiated cells. Concomitantly, there was a significant upregulation of ceramides CER[NDS] and CER[NS], along with increased sphingomyelinase activity. Pathway analysis further confirmed that SM metabolism was the most significantly affected pathway in both non-irradiated and UVB-irradiated keratinocytes treated with the microalgal lipid extract. Additionally, the elevation in alkylacylPE (PEo) and diacylPE (PE) species content observed in UVB-irradiated keratinocytes following treatment with the microalgal extract suggested the potential induction of pro-survival mechanisms through autophagy in these cells. Conversely, a noteworthy reduction in LPC content in UVB-irradiated keratinocytes treated with the extract, indicated the anti-inflammatory properties of the lipid extract obtained from microalgae. However, to fully comprehend the observed alterations in the phospholipid profile of UVB-irradiated keratinocytes, further investigations are warranted to identify the specific fraction of compounds responsible for the activity of the Nannochloropsis oceanica extract.

Astaxanthin: Past, Present, and Future

Astaxanthin (AX), a lipid-soluble pigment belonging to the xanthophyll carotenoids family, has recently garnered significant attention due to its unique physical properties, biochemical attributes, and physiological effects. Originally recognized primarily for its role in imparting the characteristic red-pink color to various organisms, AX is currently experiencing a surge in interest and research. The growing body of literature in this field predominantly focuses on AXs distinctive bioactivities and properties. However, the potential of algae-derived AX as a solution to various global environmental and societal challenges that threaten life on our planet has not received extensive attention. Furthermore, the historical context and the role of AX in nature, as well as its significance in diverse cultures and traditional health practices, have not been comprehensively explored in previous works. This review article embarks on a comprehensive journey through the history leading up to the present, offering insights into the discovery of AX, its chemical and physical attributes, distribution in organisms, and biosynthesis. Additionally, it delves into the intricate realm of health benefits, biofunctional characteristics, and the current market status of AX. By encompassing these multifaceted aspects, this review aims to provide readers with a more profound understanding and a robust foundation for future scientific endeavors directed at addressing societal needs for sustainable nutritional and medicinal solutions. An updated summary of AXs health benefits, its present market status, and potential future applications are also included for a well-rounded perspective.

Astaxanthin impact on brain: health potential and market perspective

Nowadays, there is an emergent interest in new trend-driven biomolecules to improve health and wellbeing, which has become an interesting and promising field, considering their high value and biological potential. Astaxanthin is one of these promising biomolecules, with impressive high market growth, especially in the pharmaceutical and food industries. This biomolecule, obtained from natural sources (i.e., microalgae), has been reported in the literature to have several beneficial health effects due to its biological properties. These benefits seem to be mainly associated with Astaxanthin's high antioxidant and anti-inflammatory properties, which may act on several brain issues, thus attenuating symptoms. In this sense, several studies have demonstrated the impact of astaxanthin on a wide range of diseases, namely on brain disorders (such as Alzheimer's disease, Parkinson, depression, brain stroke and autism). Therefore, this review highlights its application in mental health and illness. Furthermore, a S.W.O.T. analysis was performed to display an approach from the market/commercial perspective. However, to bring the molecule to the market, there is still a need for more studies to increase deep knowledge regarding the real impact and mechanisms in the human brain.HIGHLIGHTSAstaxanthin has been mainly extracted from the algae Haematococcus pluvialisAstaxanthin, bioactive molecule with high antioxidant and anti-inflammatory propertiesAstaxanthin has an important protective effect on brain disordersAstaxanthin is highly marketable, mainly for food and pharmaceutical industries.

Effects of Astaxanthin supplementation on selected metabolic parameters, anthropometric indices, Sirtuin1 and TNF-α levels in patients with coronary artery disease: A randomized, double-blind, placebo-controlled clinical trial

Background

Atherosclerosis can develop as a result of an increase in oxidative stress and concurrently rising levels of inflammation. Astaxanthin (AX), a red fat-soluble pigment classified as a xanthophyll, may be able to prevent the vascular damage induced by free radicals and the activation of inflammatory signaling pathways. The objective of the current study is to assess the effects of AX supplementation on cardiometabolic risk factors in individuals with coronary artery disease (CAD).

Methods

This randomized double-blind placebo-controlled clinical trial was conducted among 50 CAD patients. Participants were randomly allocated into two groups to intake either AX supplements (12 mg/day) or placebo for 8 weeks. Lipid profile, glycemic parameters, anthropometric indices, body composition, Siruin1 and TNF-α levels were measured at baseline and after 8 weeks.

Results

Body composition, glycemic indices, serum levels of TNF-α, Sirtuin1 did not differ substantially between the AX and placebo groups (p > 0.05). The data of AX group showed significant reduction in total cholesterol (−14.95 ± 33.57 mg/dl, p < 0.05) and LDL-C (−14.64 ± 28.27 mg/dl, p < 0.05). However, TG and HDL-C levels could not be affected through AX supplementation.

Conclusion

Our results suggest that AX supplementation play a beneficial role in reducing some components of lipid profile levels. However, further clinical investigations in CAD patients are required to obtain more conclusive findings.

Clinical trial registration

www.Irct.ir., identifier IRCT20201227049857N1.

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

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

Nose to Brain Delivery of Astaxanthin–Loaded Nanostructured Lipid Carriers in Rat Model of Alzheimer’s Disease: Preparation, in vitro and in vivo Evaluation

Background

Astaxanthin (AST) is a second-generation antioxidant with anti-inflammatory and neuroprotective properties and could be a promising candidate for Alzheimer's disease (AD) therapy, but is shows poor oral bioavailability due to its high lipophilicity.

Purpose

This study aimed to prepare and evaluate AST-loaded nanostructured lipid carriers (NLCs), for enhanced nose-to-brain drug delivery to improve its therapeutic efficacy in rat model of AD.

Methods

AST-NLCs were prepared using hot high-pressure homogenization technique, and processing parameters such as total lipid-to-drug ratio, solid lipid-to-liquid lipid ratio, and concentration of surfactant were optimized.

Results

The optimized AST-NLCs had a mean particle size of 142.8 ± 5.02 nm, polydispersity index of 0.247 ± 0.016, zeta potential of -32.2 ± 7.88 mV, entrapment efficiency of 94.1 ± 2.46%, drug loading of 23.5 ± 1.48%, and spherical morphology as revealed by transmission electron microscopy. Differential scanning calorimetry showed that AST was molecularly dispersed in the NLC matrix in an amorphous state, whereas Fourier transform infrared spectroscopy indicated that there is no interaction between AST and lipids. AST displayed a biphasic release pattern from NLCs; an initial burst release followed by sustained release for 24 h. AST-NLCs were stable at 4-8 ±2°C for six months. Intranasal treatment of AD-like rats with the optimized AST-NLCs significantly decreased oxidative stress, amyloidogenic pathway, neuroinflammation and apoptosis, and significantly improved the cholinergic neurotransmission compared to AST-solution. This was observed by the significant decline in the levels of malondialdehyde, nuclear factor-kappa B, amyloid beta (Aβ_1‑42), caspase-3, acetylcholinesterase, and β-site amyloid precursor protein cleaving enzyme-1 expression, and significant increase in the contents of acetylcholine and glutathione after treatment with AST-NLCs.

Conclusion

NLCs enhanced the intranasal delivery of AST and significantly improved its therapeutic properties.

ALSUntangled # 69: astaxanthin

ALSUntangled reviews alternative and off-label treatments for people living with amyotrophic lateral sclerosis (PALS). Here we review astaxanthin which has plausible mechanisms for slowing ALS progression including antioxidant, anti-inflammatory, and anti-apoptotic effects. While there are no ALS-specific pre-clinical studies, one verified "ALS reversal" occurred in a person using a combination of alternative therapies which included astaxanthin. There have been no trials of astaxanthin in people living with ALS. Natural astaxanthin appears to be safe and inexpensive. Based on the above information, we support further pre-clinical and/or clinical trials of astaxanthin in disease models and PALS, respectively, to further elucidate efficacy.

Effects of diet containing astaxanthin on visual function in healthy individuals: a randomized, double-blind, placebo-controlled, parallel study

Visual display terminal work has increased rapidly in recent years. Loss of visual acuity is an unfortunate associated effect. Here, we performed a randomized, placebo-controlled study in 60 healthy adults. Participants received a diet containing astaxanthin (9 mg/day) or placebo for 6 weeks. Visual acuity, functional visual acuity, and pupil constriction rate were measured before and after visual display terminal work. In participants aged ≥40 years, corrected visual acuity of the dominant eye after visual display terminal work at 6 weeks after intake demonstrated a higher protective effect of astaxanthin in the astaxanthin group vs the control group (p<0.05). In participants aged <40 years, no significant difference was seen between the astaxanthin and control groups. Moreover, no significant difference was found in functional visual acuity and pupil constriction rate between the astaxanthin and control groups. These results suggest astaxanthin reduces oxidative stress caused by visual display terminal work. Age-related reduction in ciliary muscle strength is likely the main detractor of visual acuity. Correspondingly, astaxanthin reduced visual display terminal work-induced visual stress in the middle-aged and elderly. This study was registered in the UMIN-CTR database (UMIN000043089).

The Role of Astaxanthin as a Nutraceutical in Health and Age-Related Conditions

The current review provides an up-to-date analysis of scientific data on astaxanthin (ASX) sources and experimental studies on its health benefits as a potent antioxidant in the aging process. ASX is a liposoluble carotenoid nutrient and reddish-orange pigment, naturally synthesized by numerous microalgae, yeasts, and bacteria as secondary metabolites. Provides a reddish hue to redfish and shellfish flesh that feed on ASX-producing microorganisms. The microalga Haematococcus pluvialis is the most important source for its industrial bioproduction. Due to its strong antioxidant properties, numerous investigations reported that natural ASX is a more significant antioxidant agent than other antioxidants, such as vitamin C, vitamin E, and β-carotene. Furthermore, several data show that ASX possesses important nutraceutical applications and health benefits, especially in healthy aging processes. However, further studies are needed for a deeper understanding of the potential mechanisms through which ASX could lead to its effective role in the healthy aging process, such as supporting brain health and skin homeostasis. This review highlights the current investigations on the effective role of ASX in oxidative stress, aging mechanisms, skin physiology, and central nervous system functioning, and shows the potential clinical implications related to its consumption.

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.

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 Influence on Health Outcomes of Adults at Risk of Metabolic Syndrome: A Systematic Review and Meta-Analysis

The use of medication is effective in managing metabolic syndrome (MetS), but side effects have led to increased attention on using nutraceuticals and supplements. Astaxanthin shows positive effects in reducing the risk of MetS, but results from individual studies are inconclusive. This systematic review summarizes the latest evidence of astaxanthin in adults with risk factors of MetS. A systematic search of English and Chinese randomized controlled trials in 14 electronic databases from inception to 30 June 2021 was performed. Two reviewers independently screened the titles and abstracts, and conducted full-text review, quality appraisal, and extraction of data. Risk of bias was assessed by PEDro. A total of 7 studies met the inclusion criteria with 321 participants. Six studies were rated to have excellent methodological quality, while the remaining one was rated at good. Results show marginal effects of astaxanthin on reduction in total cholesterol and systolic blood pressure, and a significant attenuating effect on low-density lipoprotein cholesterol. Further robust evidence is needed to examine the effects of astaxanthin in adults at risk of MetS.

Effect of Paprika Xanthophyll Supplementation on Cognitive Improvement in a Multitasking Exercise: A Pilot Study for Middle-Aged and Older Adults

Ingestion of paprika xanthophyll supplement (PX), which has antioxidant effects, has been recently reported to maintain red blood cell deformability and improve oxygen delivery efficiency. Therefore, we hypothesized that the brain activation induced by multitasking exercise in middle-aged and older participants along with the improved erythrocyte oxygen-carrying efficiency induced by PX supplementation would show a synergistic effect, increasing oxygen supply to the brain and improving cognitive function more effectively. In study 1, cerebral blood flow measurements were conducted during the multitasking exercise and cognitive function tests to verify their effect on cognitive function. The results confirmed that cerebral blood flow increased during the exercise and cognitive function improved after the exercise. In study 2, we compared the effects of the multitasking exercise on cognitive function before and after PX supplementation in middle-aged and older participants to evaluate the effects of PX supplementation. The results suggested that PX supplementation enhanced the effects of active multitasking exercise on cognitive function. We speculate that the improvement of oxygen transport efficiency by PX resulted in more effective oxygen supply, allowing the multitasking exercise to occur more effectively, which was reflected as an improvement in the cognitive function.

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.

Lipid oxidation that is, and is not, inhibited by vitamin E: Consideration about physiological functions of vitamin E

Lipids are oxidized in vivo by multiple oxidizing species with different properties, some by regulated manner to produce physiological mediators, while others by random mechanisms to give detrimental products. Vitamin E plays an important role as a physiologically essential antioxidant to inhibit unregulated lipid peroxidation by scavenging lipid peroxyl radicals to break chain propagation independent of the type of free radicals which induce chain initiation. Kinetic data suggest that vitamin E does not act as an efficient scavenger of nitrogen dioxide radical, carbonate anion radical, and hypochlorite. The analysis of regio- and stereo-isomer distribution of the lipid oxidation products shows that, apart from lipid oxidation by CYP enzymes, the free radical-mediated lipid peroxidation is the major pathway of lipid oxidation taking place in humans. Compared with healthy subjects, the levels of racemic and trans,trans-hydro (pero)xyoctadecadienoates, specific biomarker of free radical lipid oxidation, are elevated in the plasma of patients including atherosclerosis and non-alcoholic fatty liver diseases. α-Tocopherol acts as a major antioxidant, while γ-tocopherol scavenges nitrogen dioxide radical, which induces lipid peroxidation, nitration of aromatic compounds and unsaturated fatty acids, and isomerization of cis-fatty acids to trans-fatty acids. It is essential to appreciate that the antioxidant effects of vitamin E depend on the nature of both oxidants and substrates being oxidized. Vitamin E, together with other antioxidants such as vitamin C, contributes to the inhibition of detrimental oxidation of biological molecules and thereby to the maintenance of human health and prevention of diseases.

Investigation of Lipoproteins Oxidation Mechanisms by the Analysis of Lipid Hydroperoxide Isomers

The continuous formation and accumulation of oxidized lipids (e.g., lipid hydroperoxides (LOOH)) which are present even in plasma lipoproteins of healthy subjects, are ultimately considered to be linked to various diseases. Because lipid peroxidation mechanisms (i.e., radical, singlet oxygen, and enzymatic oxidation) can be suppressed by certain proper antioxidants (e.g., radical oxidation is efficiently suppressed by tocopherol), in order to suppress lipid peroxidation successfully, the determination of the peroxidation mechanism involved in the formation of LOOH is deemed crucial. In this study, to determine the peroxidation mechanisms of plasma lipoproteins of healthy subjects, we develop novel analytical methods using liquid chromatography-tandem mass spectrometry (LC-MS/MS) for 1-palmitoyl-2-linoleoyl-sn-glycero-3-phosphocholine hydroperoxide (PC 16:0/18:2;OOH) and cholesteryl linoleate hydroperoxide (CE 18:2;OOH) isomers. Using the newly developed methods, these PC 16:0/18:2;OOH and CE 18:2;OOH isomers in the low-density lipoprotein (LDL) and high-density lipoprotein (HDL) of healthy subjects are analyzed. Consequently, it is found that predominant PC 16:0/18:2;OOH and CE 18:2;OOH isomers in LDL and HDL are PC 16:0/18:2;9OOH, PC 16:0/18:2;13OOH, CE 18:2;9OOH, and CE 18:2;13OOH, which means that PC and CE in LDL and HDL are mainly oxidized by radical and/or enzymatic oxidation. In conclusion, the insights about the oxidation mechanisms shown in this study would be useful for a more effective suppression of oxidative stress in the human organism.

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.

Systematic Review and Meta-Analysis on the Effects of Astaxanthin on Human Skin Ageing

Context: Astaxanthin (ASX), a xanthophyll carotenoid derived from microalgae Haematococcus pluvialis, mitigating skin photoaging and age-related skin diseases by its antioxidant and anti-inflammatory effects in animal studies. Objective: The aim was to systematically evaluate if ASX applications have anti-ageing effects in humans. Methods: A comprehensive search of PubMed, Scopus and Web of Science found a total of eleven studies. Nine randomised, controlled human studies assessed oral ASX effects and two open-label, prospective studies evaluated topical, oral-topical ASX effects on skin ageing. GetData Graph Digitizer was used to extract mean values and standard deviations of baseline and endpoint, and Cochrane Collaboration’s tool assessed RoB for all included studies. Review Manager 5.4 was used to conduct meta-analysis of RCTs; the results were reported as effect size ± 95% confidence interval. Results: Oral ASX supplementation significantly restored moisture content (SMD = 0.53; 95% CI = 0.05, 1.01; I² = 52%; p = 0.03) and improved elasticity (SMD = 0.77; 95% CI = 0.19, 1.35; I² = 75%; p = 0.009) but did not significantly decrease wrinkle depth (SMD = −0.26; 95% CI = −0.58, 0.06; I² = 0%; p = 0.11) compared to placebo. Open-label, prospective studies suggested slightly protective effects of topical and oral-topical ASX applications on skin ageing. Conclusions: Ingestion and/or topical usages of ASX may be effective in reducing skin ageing and have promising cosmetical potential, as it improves moisture content and elasticity and reduces wrinkles.

Astaxanthin from Haematococcus pluvialis: processes, applications, and market

Astaxanthin is a xanthophyll carotenoid widely used in aquaculture and nutraceutical industries. Among natural sources, the microalga Haematococcus pluvialis is the non-genetically modified organism with the greatest capacity to accumulate astaxanthin. Therefore, it is important to understand emerging strategies in upstream and downstream processing of astaxanthin from this microalga. This review covers all aspects regarding the production and the market of natural astaxanthin from H. pluvialis. Astaxanthin biosynthesis, metabolic pathways, and nutritional metabolisms from the green vegetative motile to red hematocyst stage were reviewed in detail. Also, traditional and emerging techniques on biomass harvesting and astaxanthin recovery were presented and evaluated. Moreover, the global market of astaxanthin was discussed, and guidelines for sustainability increasing of the production chain of astaxanthin from H. pluvialis were highlighted, based on biorefinery models. This review can serve as a baseline on the current knowledge of H. pluvialis and encourage new researchers to enter this field of research.

Effects of Dietary Food Components on Cognitive Functions in Older Adults

Population aging has recently been an important issue as the number of elderly people is growing worldwide every year, and the extension of social security costs is financially costly. The increase in the number of elderly people with cognitive decline is a serious problem related to the aging of populations. Therefore, it is necessary to consider not only physical care but also cognitive patterns in the future care of older adults. Since food contains a variety of bioactive substances, dietary patterns may help improve age-related cognitive decline. However, the relationship between cognitive function and individual food components remains ambiguous as no clear efficacy or mechanism has been confirmed. Against this background, this review summarizes previous reports on the biological process of cognitive decline in the elderly and the relationship between individual compounds in foods and cognitive function, as well as the role of individual components of food in cognitive function, in the following order: lipids, carotenoids, vitamins, phenolic compounds, amino acids, peptides, and proteins. Based on the research presented in this review, a proper diet that preserves cognitive function has the potential to improve age-related cognitive decline, Alzheimer's disease, and Parkinson's disease. Hopefully, this review will help to trigger the development of new foods and technologies that improve aging and cognitive functions and extend the healthy life span.

Therapeutic potential of astaxanthin and superoxide dismutase in Alzheimer's disease

Oxidative stress, the imbalance of the antioxidant system, results in an accumulation of neurotoxic proteins in Alzheimer's disease (AD). The antioxidant system is composed of exogenous and endogenous antioxidants to maintain homeostasis. Superoxide dismutase (SOD) is an endogenous enzymatic antioxidant that converts superoxide ions to hydrogen peroxide in cells. SOD supplementation in mice prevented cognitive decline in stress-induced cells by reducing lipid peroxidation and maintaining neurogenesis in the hippocampus. Furthermore, SOD decreased expression of BACE1 while reducing plaque burden in the brain. Additionally, Astaxanthin (AST), a potent exogenous carotenoid, scavenges superoxide anion radicals. Mice treated with AST showed slower memory decline and decreased depositions of amyloid-beta (Aβ) and tau protein. Currently, the neuroprotective potential of these supplements has only been examined separately in studies. However, a single antioxidant cannot sufficiently resist oxidative damage to the brain, therefore, a combinatory approach is proposed as a relevant therapy for ameliorating pathological changes in AD.

A Critical Review of the Use of Surfactant-Coated Nanoparticles in Nanomedicine and Food Nanotechnology

Surfactants, whose existence has been recognized as early as 2800 BC, have had a long history with the development of human civilization. With the rapid development of nanotechnology in the latter half of the 20th century, breakthroughs in nanomedicine and food nanotechnology using nanoparticles have been remarkable, and new applications have been developed. The technology of surfactant-coated nanoparticles, which provides new functions to nanoparticles for use in the fields of nanomedicine and food nanotechnology, is attracting a lot of attention in the fields of basic research and industry. This review systematically describes these "surfactant-coated nanoparticles" through various sections in order: 1) surfactants, 2) surfactant-coated nanoparticles, application of surfactant-coated nanoparticles to 3) nanomedicine, and 4) food nanotechnology. Furthermore, current progress and problems of the technology using surfactant-coated nanoparticles through recent research reports have been discussed.

Beneficial effects and health benefits of Astaxanthin molecules on animal production: A review

Astaxanthin (AST) is a red pigment of carotenoid and is considered a high-quality keto-carotenoid pigment with food, livestock, cosmetic, therapeutic and nutraceutical proposes. Astaxanthin exists naturally in fish, crustacean, algae, and birds that naturally exists, principally as fatty acid esters. Many investigations have exhibited the beneficial impacts of astaxanthin when utilized as a pharmaceutical agent in animal nutrition. Astaxanthin has a variety of considerable biological actions, such as being antihypertensive, an antioxidant, anti-obesity properties, and anti-carcinogenic. Astaxanthin has recently acquired popularity as a powerful immunomodulator to maintain the health status and well-being of both animals and humans. The use of astaxanthin is broadly utilized in medical sciences and the nutrition pf aquatic species; however, it presently has limited applications in broader animal nutrition. Understanding astaxanthin's structure, source, and mode of action in the body provides a conceptual base for its clinical application and could enhance the screening of compounds associated with the treatment of many diseases. This review article aims to clarify the important aspects of astaxanthin such as its synthesis, bioavailability, and therapeutics actions, with special interest in practical applications. Awareness of this benefits and production is expected to aid the livestock industry to develop nutritional strategies that ensure the protection of animal health.

Docosahexaenoic acid-acylated astaxanthin ester exhibits superior performance over non-esterified astaxanthin in preventing behavioral deficits coupled with apoptosis in MPTP-induced mice with Parkinson's disease

Non-esterified astaxanthin (AST) has been reported to exhibit protective effects from Parkinson's disease (PD). Notably, DHA-acylated astaxanthin ester (DHA-AST) is widely distributed in the seafood. However, whether DHA-AST has an effect on PD, and the differences between DHA-AST, non-esterified AST and the combination of non-esterified AST (AST) with DHA (DHA + AST) is unclear. In the present study, mice with PD, induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), were employed to investigate the effects of DHA-AST, AST and DHA + AST on Parkinson's disease. The rotarod test results showed that DHA-AST significantly suppressed the PD development in MPTP-induced mice, and was better than the effects of AST and DHA + AST. Further mechanistic studies indicated that all three astaxanthin supplements could inhibit oxidative stress in the brain. It was noted that DHA-AST had the best ability to suppress the apoptosis of dopaminergic neurons via the mitochondria-mediated pathway and JNK and P38 MAPK pathway in the brain among the three treated groups. DHA-AST was superior to AST in preventing behavioral deficits coupled with apoptosis rather than oxidative stress, and might provide a valuable reference for the prevention and treatment of neurodegenerative diseases.

"Therapeutic uses of natural astaxanthin: An evidence-based review focused on human clinical trials"

Astaxanthin is a natural C40 carotenoid with numerous reported biological functions, most of them associated with its antioxidant and anti-inflammatory activity, standing out from other antioxidants as it has shown the highest oxygen radical absorbance capacity (ORAC), 100-500 times higher than ⍺-tocopherol and a 10 times higher free radical inhibitory activity than related antioxidants (α-tocopherol, α-carotene, β -carotene, lutein and lycopene). In vitro and in vivo studies have associated astaxanthin's unique molecular features with several health benefits, including neuroprotective, cardioprotective and antitumoral properties, suggesting its therapeutic potential for the prevention or co-treatment of dementia, Alzheimer, Parkinson, cardiovascular diseases and cancer. Benefits on skin and eye health promotion have also been reported, highlighting its potential for the prevention of skin photo-aging and the treatment of eye diseases like glaucoma, cataracts and uveitis. In this review, we summarize and discuss the currently available evidence on astaxanthin benefits, with a particular focus on human clinical trials, including a brief description of the potential mechanisms of action responsible for its biological activities.

Molecules and Mechanisms to Overcome Oxidative Stress Inducing Cardiovascular Disease in Cancer Patients

Reactive oxygen species (ROS) are molecules involved in signal transduction pathways with both beneficial and detrimental effects on human cells. ROS are generated by many cellular processes including mitochondrial respiration, metabolism and enzymatic activities. In physiological conditions, ROS levels are well-balanced by antioxidative detoxification systems. In contrast, in pathological conditions such as cardiovascular, neurological and cancer diseases, ROS production exceeds the antioxidative detoxification capacity of cells, leading to cellular damages and death. In this review, we will first describe the biology and mechanisms of ROS mediated oxidative stress in cardiovascular disease. Second, we will review the role of oxidative stress mediated by oncological treatments in inducing cardiovascular disease. Lastly, we will discuss the strategies that potentially counteract the oxidative stress in order to fight the onset and progression of cardiovascular disease, including that induced by oncological treatments.

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.

Lipid hydroperoxides in nutrition, health, and diseases

Research on lipid peroxidation in food degradation, oil and fat nutrition, and age-related diseases has gained significant international attention for the view of improvement of societal health and longevity. In order to promote basic studies on these topics, a chemiluminescence detection-high performance liquid chromatography instrument using a high-sensitivity single photon counter as a detector was developed. This instrument enabled us to selectively detect and quantify lipid hydroperoxides, a primary product of lipid peroxidation reactions, as hydroperoxide groups at the lipid class level. Furthermore, an analytical method using liquid chromatography-tandem mass spectrometry has been established to discriminate the position and stereoisomerization of hydroperoxide groups in lipid hydroperoxides. Using these two methods, the reaction mechanisms of lipid peroxidation in food and in the body have been confirmed.

Potential of natural astaxanthin in alleviating the risk of cytokine storm in COVID-19

Host excessive inflammatory immune response to SARS-CoV-2 infection is thought to underpin the pathogenesis of COVID-19 associated severe pneumonitis and acute lung injury (ALI) or acute respiratory distress syndrome (ARDS). Once an immunological complication like cytokine storm occurs, anti-viral based monotherapy alone is not enough. Additional anti-inflammatory treatment is recommended. It must be noted that anti-inflammatory drugs such as JAK inhibitors, IL-6 inhibitors, TNF-α inhibitors, colchicine, etc., have been either suggested or are under trials for managing cytokine storm in COVID-19 infections. Natural astaxanthin (ASX) has a clinically proven safety profile and has antioxidant, anti-inflammatory, and immunomodulatory properties. There is evidence from preclinical studies that supports its preventive actions against ALI/ARDS. Moreover, ASX has a potent PPARs activity. Therefore, it is plausible to speculate that ASX could be considered as a potential adjunctive supplement. Here, we summarize the mounting evidence where ASX is shown to exert protective effect by regulating the expression of pro-inflammatory factors IL-1β, IL-6, IL-8 and TNF-α. We present reports where ASX is shown to prevent against oxidative damage and attenuate exacerbation of the inflammatory responses by regulating signaling pathways like NF-ĸB, NLRP3 and JAK/STAT. These evidences provide a rationale for considering natural astaxanthin as a therapeutic agent against inflammatory cytokine storm and associated risks in COVID-19 infection and this suggestion requires further validation with clinical studies.

Cognitive function improvement with astaxanthin and tocotrienol intake: a randomized, double-blind, placebo-controlled study

We examined the effects of the mixed ingestion of astaxanthin derived from Haematococcus pluvialis and tocotrienols on the cognitive function of healthy Japanese adults who feel a memory decline. Forty-four subjects were randomly but equally assigned to the astaxanthin-tocotrienols or placebo group. An astaxanthin-tocotrienols or placebo capsule was taken once daily before or after breakfast for a 12-week intervention period. The primary outcome was composite memory from the Cognitrax cognitive test, and the secondary outcomes were other cognitive functions and subjective symptoms for memory. Each group included 18 subjects in the efficacy analysis (astaxanthin-tocotrienols group, 55.4 ± 7.9 years; placebo group, 54.6 ± 6.9 years). The astaxanthin-tocotrienols group showed a significant improvement in composite memory and verbal memory in Cognitrax at Δ12 weeks compared with the placebo group. Additionally, the astaxanthin-tocotrienols group showed a significant improvement in the subjective symptom of "During the last week, have you had trouble remembering people's names or the names of things?" compared with the placebo group after 12 weeks. No adverse events were observed in this study. The results demonstrated that taking an astaxanthin-tocotrienols combination improves the composite memory and verbal memory of Japanese adults who feel a memory decline (UMIN 000031758).

Novel Insights into the Biotechnological Production of Haematococcus pluvialis-Derived Astaxanthin: Advances and Key Challenges to Allow Its Industrial Use as Novel Food Ingredient

Astaxanthin shows many biological activities. It has acquired a high economic potential and its current market is dominated by its synthetic form. However, due to the increase of the health and environmental concerns from consumers, natural forms are now preferred for human consumption. Haematococcus pluvialis is artificially cultured at an industrial scale to produce astaxanthin used as a dietary supplement. However, due to the high cost of its cultivation and its relatively low biomass and pigment productivities, the astaxanthin extracted from this microalga remains expensive and this has probably the consequence of slowing down its economic development in the lower added-value market such as food ingredient. In this review, we first aim to provide an overview of the chemical and biochemical properties of astaxanthin, as well as of its natural sources. We discuss its bioavailability, metabolism, and biological activities. We present a state-of-the-art of the biology and physiology of H. pluvialis, and highlight novel insights into the biotechnological processes which allow optimizing the biomass and astaxanthin productivities. We are trying to identify some lines of research that would improve the industrial sustainability and economic viability of this bio-production and to broaden the commercial potential of astaxanthin produced from H. pluvialis.

Astaxanthin Ameliorated Parvalbumin-Positive Neuron Deficits and Alzheimer's Disease-Related Pathological Progression in the Hippocampus of AppNL-G-F/NL-G-F Mice

Growing evidence suggests that oxidative stress due to amyloid β (Aβ) accumulation is involved in Alzheimer's disease (AD) through the formation of amyloid plaque, which leads to hyperphosphorylation of tau, microglial activation, and cognitive deficits. The dysfunction or phenotypic loss of parvalbumin (PV)-positive neurons has been implicated in cognitive deficits. Astaxanthin is one of carotenoids and known as a highly potent antioxidant. We hypothesized that astaxanthin's antioxidant effects may prevent the onset of cognitive deficits in AD by preventing AD pathological processes associated with oxidative stress. In the present study, we investigated the effects of astaxanthin intake on the cognitive and pathological progression of AD in a mouse model of AD. The App^{NL-G-F/NL-G-F} mice were fed with or without astaxanthin from 5-to-6 weeks old, and cognitive functions were evaluated using a Barnes maze test at 6 months old. PV-positive neurons were investigated in the hippocampus. Aβ42 deposits, accumulation of microglia, and phosphorylated tau (pTau) were immunohistochemically analyzed in the hippocampus. The hippocampal anti-oxidant status was also investigated. The Barnes maze test indicated that astaxanthin significantly ameliorated memory deficits. Astaxanthin reduced Aβ42 deposition and pTau-positive areal fraction, while it increased PV-positive neuron density and microglial accumulation per unit fraction of Aβ42 deposition in the hippocampus. Furthermore, astaxanthin increased total glutathione (GSH) levels, although 4-hydroxy-2,3-trans-nonenal (4-HNE) protein adduct levels (oxidative stress marker) remained high in the astaxanthin supplemented mice. The results indicated that astaxanthin ameliorated memory deficits and significantly reversed AD pathological processes (Aβ42 deposition, pTau formation, GSH decrease, and PV-positive neuronal deficits). The elevated GSH levels and resultant recovery of PV-positive neuron density, as well as microglial activation, may prevent these pathological processes.

Effect of astaxanthin-rich extract derived from Paracoccus carotinifaciens on the status of stress and sleep in adults

This study investigated the effect of a dietary supplement containing astaxanthin-rich extract derived from Paracoccus carotinifaciens (astaxanthin supplement) on the status of stress and sleep in individuals aged 20-64 years. Twenty-five subjects orally administered 12 mg astaxanthin/day of astaxanthin supplement for 8 weeks (astaxanthin group) and 29 subjects given a placebo (placebo group) were evaluated with Profile of Mood States 2nd Edition for stress and Oguri-Shirakawa-Azumi Sleep Inventory for Middle-aged and Aged version for sleep. We did not observe any significant intergroup differences in the stress and sleep. A subgroup analysis was performed after dividing the subjects into two groups: those who scored >65 and those who scored ≤65 in the "Depression-Dejection" dimension of Profile of Mood States 2nd Edition. The sleep of subjects who scored >65 ("Depression-Dejection") showed significant improvement in the astaxanthin group compared with the placebo group, whereas no significant improvement was observed in stress and the other subjects. Our results indicate that people who tend to be strongly depressed may experience improved sleep after ingesting astaxanthin supplement. On the basis of the parameters tested, administration of astaxanthin supplement was not associated with any problems related to safety. Clinical registration: This study has been registered at the University Hospital Medical Information Network (https://upload.umin.ac.jp/cgi-open-bin/ctr/ctr_view.cgi?recptno=R000038619) on August 24, 2018 as "A study to evaluate the effect of intake of astaxanthin on the status of stress and sleep in adults," Identification No. UMIN000033863.

Asthaxanthin Improves Aerobic Exercise Recovery Without Affecting Heat Tolerance in Humans

Objectives: To examine the supplementation effects of the xanthophyll carotenoid Astaxanthin on physical performance and exertional heat strain in humans.

Design: A randomized double blind placebo controlled trial.

Methods: Twenty two male participants (Age: 23.14 ± 3.5 y, height: 175 ± 6 cm, body mass: 69.6 ± 8.7 kg, % body fat: 16.8 ± 3.8) received placebo (PLA, n = 10) or Astaxanthin (ATX, n = 12) 12 mg/day Per os (P.O), for 30 days, and were tested pre and post-supplementation with a maximal oxygen uptake (VO₂ Max) test and the heat tolerance test (HTT) (2 h walk at 40°C, 40% relative humidity (RH), 5 kph, 2% incline). NIH database registration no. NCT02088242. Gas exchange, Heart rate (HR), Relative perceived exertion (RPE), and blood lactate were measured during the VO₂ Max test. Heart rate (HR), rectal (Trec), and skin (Tskin) temperatures, RPE, and sweat rate (SR) were monitored in the HTT. Serum heat shock protein 72 (HSP72), Creatine phospho-kinase (CPK), C-reactive protein (CRP), and lipid profile were measured before and after the test.

Results: The rise in blood lactate caused by the VO₂ Max test was significantly diminished in the ATX group (9.4 ± 3.1 and 13.0 ± 3.1 mmole^*l⁻¹ in the ATX and PLA groups, respectively P < 0.02), as was the change in oxygen uptake during recovery (−2.02 ± 0.64 and 0.83 ± 0.79% of VO₂ Max in the ATX and PLA group, respectively, p = 0.001). No significant differences were observed in the anaerobic threshold or VO₂ Max. In the HTT, no significant physiological or biochemical differences were observed (HR <120 bpm, Trec rose by ~1°C to <38°C, no difference in SR).

Conclusions: Astaxanthin supplementation improved exercise recovery. No benefit was observed for ATX over PLA in response to heat stress. Further examination of Astaxanthin in higher exertional heat strain is required.

Carotenoids and Markers of Oxidative Stress in Human Observational Studies and Intervention Trials: Implications for Chronic Diseases

Carotenoids include C30, C40 and C50 terpenoid-based molecules, many of which constitute coloured pigments. However, >1100 of these are known to occur in nature and only about a dozen are known to play a role in our daily diet. Carotenoids have received much attention due to their proposed health benefits, including reducing the incidence of chronic diseases, such as cardiovascular disease and diabetes. Many of these diseases are characterized by chronic inflammation co-occurring with oxidative stress, characterized by, for example, enhanced plasma F2-isoprostane concentrations, malondialdehyde, and 8-hydroxyguanosine. Though carotenoids can act as direct antioxidants, quenching, for example, singlet oxygen and peroxide radicals, an important biological function appears to rest also in the activation of the body's own antioxidant defence system, related to superoxide-dismutase, catalase, and glutathione-peroxidase expression, likely due to the interaction with transcription factors, such as nuclear-factor erythroid 2-related factor 2 (Nrf-2). Though mostly based on small-scale and observational studies which do not allow for drawing conclusions regarding causality, several supplementation trials with isolated carotenoids or food items suggest positive health effects. However, negative effects have also been reported, especially regarding beta-carotene for smokers. This review is aimed at summarizing the results from human observational studies/intervention trials targeting carotenoids in relation to chronic diseases characterized by oxidative stress and markers thereof.

Effects of Composite Supplement Containing Astaxanthin and Sesamin on Cognitive Functions in People with Mild Cognitive Impairment: A Randomized, Double-Blind, Placebo-Controlled Trial

Background:

Dementia and its first or transitional stage, mild cognitive impairment (MCI), is a major concern for the aging Japanese society. Thus, the use of dietary supplements to improve or maintain cognitive function has become a topic of public interest.

Objective:

In this study, we evaluated the effects of a composite supplement containing food-derived antioxidants, specifically astaxanthin and sesamin (AS), on cognitive function in people with MCI.

Method:

Twenty-one healthy participants with MCI were recruited in our double-blind placebo-controlled pilot study. They were assigned to either an AS group, who received ingestible capsules containing AS, or a placebo group, who received identical placebo capsules. To assess cognitive functions, we performed the Japanese version of the Central Nervous System Vital Signs (CNSVS) test and the Alzheimer’s Disease Assessment Scale-Cog test at baseline, after 6 weeks, and after 12 weeks of dietary supplementation.

Results:

The CNSVS test revealed significant improvements in psychomotor speed and processing speed in the AS group compared with the placebo group, suggesting that the daily supplementation of AS improved cognitive functions related to the ability to comprehend, and perform complex tasks quickly and accurately.

Conclusion:

Our results provide support for the use of AS as a dietary supplementation for improving cognitive functions.

Effects of Astaxanthin Supplementation on Oxidative Stress

A systematic review and meta-analysis was conducted in six databases from 1948 to 2015 to assess the antioxidant activity of astaxanthin in humans. Nine randomized controlled trials were included in the systematic review. Results of meta-analysis revealed a borderline significant antioxidant effect of astaxanthin between the intervention and control groups, with a malondialdehyde-lowering effect for lipid peroxidation (p = 0.050). However, the data included here are insufficient. When compared with the baseline in intervention groups, the meta-analysis suggested that astaxanthin supplements significantly decreased plasma malondialdehyde {Standard mean difference (SMD) -1.32 μmol/L [95% CI -1.92, -0.72]; p < 0.0001} and isoprostane (SMD -3.10 ng/mL [95% CI -4.69, -1.51]; p < 0.0001). However, they increased superoxide dismutase (SMD 1.57 U/mL [95% CI 0.57, 2.56]; p = 0.002) and total antioxidant capacity (SMD 0.77 mmol 95% CI [0.12, 1.43]; p = 0.018). For dosage subgroup analysis, high dose (≥20 mg/day) of astaxanthin showed significant antioxidant effect (on total antioxidant capacity, isoprostane, and superoxide dismutase, p < 0.05). However, low dose (<20 mg/day) showed no significant effect (p > 0.05). Further duration subgroup analysis indicated that astaxanthin showed antioxidant effect after a 3-week intervention (p < 0.001), whereas this effect was not observed after a 12-week or 3-month intervention (on isoprostane and superoxide dismutase, p > 0.05). This review suggested that the antioxidant effect of astaxanthin on humans is unclear.

Evaluation of γ-oryzanol Accumulation and Lipid Metabolism in the Body of Mice Following Long-Term Administration of γ-oryzanol

γ-Oryzanol (OZ), abundant in rice bran oil, has gained attention due to its physiological activities (e.g., lipid-lowering effects). However, the absorption and metabolism of orally ingested OZ have not yet been fully elucidated. In this study, diets containing normal or high contents of OZ were fed to obesity model mice for 8 weeks, and OZ concentrations in plasma and organs were analyzed by HPLC-MS/MS. To evaluate the relationship between OZ accumulation and lipid metabolism in vivo, lipid concentrations in the mice plasma and liver were also measured. As a result, the accumulation of intact OZ in plasma and organs was seen in mice fed diets containing OZ, where mice fed diets containing higher OZ contents demonstrated higher levels of OZ accumulation and lower amounts of plasma lipids. These results, in combination with our additional data from a single oral administration test, suggest the possibility that intact OZ, along with its metabolites (e.g., ferulic acid), is biologically-active.

NUtraceutical TReatment for hYpercholesterolemia in HIV-infected patients: The NU-TRY(HIV) randomized cross-over trial

BACKGROUND AND AIMS

Despite hypercholesterolemia has been recognized to increase cardiovascular risk in human immunodeficiency virus (HIV)-infected patients, cholesterol-lowering therapy is underused in this population, due to fear of drug-drug interactions with antiretroviral therapy (ART). We investigated the effects of a nutraceutical combination (NC) on lipid profile, proprotein convertase subtilisin/kexin type 9 (PCSK9), subclinical inflammation and arterial stiffness in ART-treated HIV-infected patients.

METHODS

This was a prospective randomized open-label trial with a cross-over design including 30 stable HIV-infected patients on ART with low-density lipoprotein cholesterol (LDL-C) >115 mg/dL, not taking lipid-lowering treatment. After a 3-week lipid stabilization period, the effects associated with 3 months of an oral NC containing red yeast rice and berberine vs. no active treatment (noNC) were assessed for plasma total cholesterol (TC), LDL-C, high-density lipoprotein cholesterol (HDL-C), triglyceride (TG), lipoprotein(a), PCSK9, high-sensitivity C-reactive protein (hs-CRP) levels and aortic pulse wave velocity (aPWV).

RESULTS

At baseline, significant correlations between PCSK9 levels, age (rho = -0.51, p=0.004), waist circumference (rho = 0.36, p=0.005) and CD4⁺ cell count (rho = -0.40, p=0.027) were observed. NC treatment effects corrected for noNC were significant for TC (-14%, p<0.001), LDL-C (-19%, p<0.001), PCSK9 (-12%, p=0.02), hs-CRP (-14%, p=0.03) and aPWV (-6%, p=0.005). No significant effects were observed for HDL-C, TG and lipoprotein(a). NC treatment was safe and no significant alterations in muscle, liver and immunovirological parameters were observed. No carry over effect was recorded.

CONCLUSIONS

The tested NC significantly reduced plasma cholesterol and PCSK9 levels, attenuated subclinical inflammation and improved arterial stiffness in stable HIV-infected patients on ART.