Subchronic (13-week) toxicity and prenatal developmental toxicity studies of dietary astaxanthin in rats

Xanthophyllomyces dendrorhous Is a Safe Dietary Supplement with Potent Antioxidant Defense Enhancing Activity

Xanthophyllomyces dendrorhous (X. dendrorhous), previously known as Phaffia rhodozyma, is a red yeast that is widely recognized as a rich source of carotenoids, particularly astaxanthin, which exhibits potent antioxidant activity and other health-promoting functions. However, there is currently a lack of research on the safety of consuming X. dendrorhous. To address this, we conducted an acute toxicity study followed by a 90-day subchronic toxicity trial to evaluate the safety of X. dendrorhous and investigate its in vivo antioxidant activity. In the acute toxicity study, Sprague-Dawley rats were administered a maximum of 12 g/kg body weight of X. dendrorhous powder by gavage and survived without any adverse effects for 14 days. In the subsequent subchronic toxicity test, the rats were randomly divided into five groups, each with free access to their diet adulterated with 0% (control), 2.5% (low), 5% (middle), 10% (high), and 20% (extreme high) X. dendrorhous powder. The rats' behavior, body weight, and food intake were monitored during the 90-day experiment. At the end of the experiment, urine, blood, and organs were collected from the rats for biochemical testing. Additionally, the antioxidant activity in rat sera was evaluated. The results of the acute toxicity test demonstrated that the LD50 of X. dendrorhous was greater than 12 g/kg body weight, indicating that the substance was not toxic. Throughout the 90-day period of subchronic toxicity, the triglyceride levels of male rats fed with 10 and 20% X. dendrorhous increased to 1.54 ± 0.17 and 1.55 ± 0.25 mmol/L (P < 0.05), respectively. This may be attributed to the elevated fat content of the diet in the high-dose and extreme high-dose groups, which was 5.5 and 2.5% higher than that in the control, respectively. Additionally, the white pulp in the spleen exhibited an increase, and the number of white blood cells in the extreme high-dose group increased by 2.41 × 109/L (P < 0.05), which may contribute to enhanced immunity. Finally, the body weight, food intake, blood and urine indexes, and histopathological examination results of the organs of the rats did not demonstrate any regular toxic effects. With the adulteration of X. dendrorhous, the activity of GSH-Px in male rats increased by 16-36.32%. The activity of GSH-Px in female rats of the extreme high-dose group increased by 14.70% (P < 0.05). The free radical scavenging ability of ABTS in male rats in the two high-dose groups exhibited an increase of 6.5 and 11.41% (P < 0.05). In contrast, the MDA content of male rats in the extreme high-dose group demonstrated a reduction of 2.73 nmol/mL (P < 0.05). These findings indicate that X. dendrorhous has no toxic effects, can be taken in high doses, and has a beneficial antioxidant effect that may enhance the body's immunity.

Traditional Chinese medicine and mitophagy: A novel approach for cardiovascular disease management

BACKGROUND

Cardiovascular disease (CVD) remains the leading cause of morbidity and mortality worldwide, imposing an enormous economic burden on individuals and human society. Laboratory studies have identified several drugs that target mitophagy for the prevention and treatment of CVD. Only a few of these drugs have been successful in clinical trials, and most studies have been limited to animal and cellular models. Furthermore, conventional drugs used to treat CVD, such as antiplatelet agents, statins, and diuretics, often result in adverse effects on patients' cardiovascular, metabolic, and respiratory systems. In contrast, traditional Chinese medicine (TCM) has gained significant attention for its unique theoretical basis and clinical efficacy in treating CVD.

PURPOSE

This paper systematically summarizes all the herbal compounds, extracts, and active monomers used to target mitophagy for the treatment of CVD in the last five years. It provides valuable information for researchers in the field of basic cardiovascular research, pharmacologists, and clinicians developing herbal medicines with fewer side effects, as well as a useful reference for future mitophagy research.

METHODS

The search terms "cardiovascular disease," "mitophagy," "herbal preparations," "active monomers," and "cardiac disease pathogenesis" in combination with "natural products" and "diseases" were used to search for studies published in the past five years until January 2024.

RESULTS

Studies have shown that mitophagy plays a significant role in the progression and development of CVD, such as atherosclerosis (AS), heart failure (HF), myocardial infarction (MI), myocardial ischemia/reperfusion injury (MI/RI), cardiac hypertrophy, cardiomyopathy, and arrhythmia. Herbal compound preparations, crude extracts, and active monomers have shown potential as effective treatments for these conditions. These substances protect cardiomyocytes by inducing mitophagy, scavenging damaged mitochondria, and maintaining mitochondrial homeostasis. They display notable efficacy in combating CVD.

CONCLUSION

TCM (including herbal compound preparations, extracts, and active monomers) can treat CVD through various pharmacological mechanisms and signaling pathways by inducing mitophagy. They represent a hotspot for future cardiovascular basic research and a promising candidate for the development of future cardiovascular drugs with fewer side effects and better therapeutic efficacy.

Astaxanthin and meclizine extend lifespan in UM-HET3 male mice; fisetin, SG1002 (hydrogen sulfide donor), dimethyl fumarate, mycophenolic acid, and 4-phenylbutyrate do not significantly affect lifespan in either sex at the doses and schedules used

In genetically heterogeneous (UM-HET3) mice produced by the CByB6F1 × C3D2F1 cross, the Nrf2 activator astaxanthin (Asta) extended the median male lifespan by 12% (p = 0.003, log-rank test), while meclizine (Mec), an mTORC1 inhibitor, extended the male lifespan by 8% (p = 0.03). Asta was fed at 1840 ± 520 (9) ppm and Mec at 544 ± 48 (9) ppm, stated as mean ± SE (n) of independent diet preparations. Both were started at 12 months of age. The 90th percentile lifespan for both treatments was extended in absolute value by 6% in males, but neither was significant by the Wang-Allison test. Five other new agents were also tested as follows: fisetin, SG1002 (hydrogen sulfide donor), dimethyl fumarate, mycophenolic acid, and 4-phenylbutyrate. None of these increased lifespan significantly at the dose and method of administration tested in either sex. Amounts of dimethyl fumarate in the diet averaged 35% of the target dose, which may explain the absence of lifespan effects. Body weight was not significantly affected in males by any of the test agents. Late life weights were lower in females fed Asta and Mec, but lifespan was not significantly affected in these females. The male-specific lifespan benefits from Asta and Mec may provide insights into sex-specific aspects of aging.

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.

Safety Assessment of 3S, 3'S Astaxanthin Derived from Metabolically Engineered K. marxianus

Previous reviews have already explored the safety and bioavailability of astaxanthin, as well as its beneficial effects on human body. The great commercial potential in a variety of industries, such as the pharmaceutical and health supplement industries, has led to a skyrocketing demand for natural astaxanthin. In this study, we have successfully optimized the astaxanthin yield up to 12.8 mg/g DCW in a probiotic yeast and purity to 97%. We also verified that it is the desired free-form 3S, 3'S configurational stereoisomer by NMR and FITR that can significantly increase the bioavailability of astaxanthin. In addition, we have proven that our extracted astaxanthin crystals have higher antioxidant capabilities compared with natural esterified astaxanthin from H. pluvialis. We also screened for potential adverse effects of the pure astaxanthin crystals extracted from the engineered probiotic yeast by dosing SD rats with 6, 12, and 24 mg/kg/day of astaxanthin crystals via oral gavages for a 13-week period and have found no significant biological differences between the control and treatment groups in rats of both genders, further confirming the safety of astaxanthin crystals. This study demonstrates that developing metabolically engineered microorganisms provides a safe and feasible approach for the bio-based production of many beneficial compounds, including astaxanthin.

Health benefits of astaxanthin against age-related diseases of multiple organs: A comprehensive review

Age-related diseases are associated with increased morbidity in the past few decades and the cost associated with the treatment of these age-related diseases exerts a substantial impact on social and health care expenditure. Anti-aging strategies aim to mitigate, delay and reverse aging-associated diseases, thereby improving quality of life and reducing the burden of age-related pathologies. The natural dietary antioxidant supplementation offers substantial pharmacological and therapeutic effects against various disease conditions. Astaxanthin is one such natural carotenoid with superior antioxidant activity than other carotenoids, as well as well as vitamins C and E, and additionally, it is known to exhibit a plethora of pharmacological effects. The present review summarizes the protective molecular mechanisms of actions of astaxanthin on age-related diseases of multiple organs such as Neurodegenerative diseases [Alzheimer's disease (AD), Parkinson's disease (PD), Stroke, Multiple Sclerosis (MS), Amyotrophic lateral sclerosis (ALS), and Status Epilepticus (SE)], Bone Related Diseases [Osteoarthritis (OA) and Osteoporosis], Cancers [Colon cancer, Prostate cancer, Breast cancer, and Lung Cancer], Cardiovascular disorders [Hypertension, Atherosclerosis and Myocardial infarction (MI)], Diabetes associated complications [Diabetic nephropathy (DN), Diabetic neuropathy, and Diabetic retinopathy (DR)], Eye disorders [Age related macular degeneration (AMD), Dry eye disease (DED), Cataract and Uveitis], Gastric Disorders [Gastritis, Colitis, and Functional dyspepsia], Kidney Disorders [Nephrolithiasis, Renal fibrosis, Renal Ischemia reperfusion (RIR), Acute kidney injury (AKI), and hyperuricemia], Liver Diseases [Nonalcoholic fatty liver disease (NAFLD), Alcoholic Liver Disease (AFLD), Liver fibrosis, and Hepatic Ischemia-Reperfusion (IR) Injury], Pulmonary Disorders [Pulmonary Fibrosis, Acute Lung injury (ALI), and Chronic obstructive pulmonary disease (COPD)], Muscle disorders (skeletal muscle atrophy), Skin diseases [Atopic dermatitis (ATD), Skin Photoaging, and Wound healing]. We have also briefly discussed astaxanthin's protective effects on reproductive health.

Astaxanthin Relieves Testicular Ischemia-Reperfusion Injury-Immunohistochemical and Biochemical Analyses

Testicular torsion potentially leads to acute scrotum and testicle loss, and requires prompt surgical intervention to restore testicular blood flow, despite the paradoxical negative effect of reperfusion. While no drug is yet approved for this condition, antioxidants are promising candidates. This study aimed to determine astaxanthin's (ASX), a potent antioxidant, effect on rat testicular torsion-detorsion injury. Thirty-two prepubertal male Fischer rats were divided into four groups. Group 1 underwent sham surgery. In group 2, the right testis was twisted at 720° for 90 min. After 90 min of reperfusion, the testis was removed. ASX was administered intraperitoneally at the time of detorsion (group 3) and 45 min after detorsion (group 4). Quantification of caspase-3 positive cells and oxidative stress markers detection were determined immunohistochemically, while the malondialdehyde (MDA) value, superoxide dismutase (SOD), and glutathione peroxidase (GPx) activities were determined by colorimetric assays. The number of apoptotic caspase-3 positive cells and the MDA value were lower in group 4 compared to group 2. A significant increase in the SOD and GPx activity was observed in group 4 compared to groups 2 and 3. We conclude that ASX has a favorable effect on testicular ischemia-reperfusion injury in rats.

Safety and efficacy of a feed additive consisting of astaxanthin-rich Phaffia rhodozyma for salmon and trout (Igene Biotechnology, Inc.)

Following a request from the European Commission, the FEEDAP Panel was asked to deliver a scientific opinion on the safety and efficacy of astaxanthin (ATX)-rich Phaffia rhodozyma. The additive, belonging to the category 'sensory additives' and the functional group 'substances which, when fed to animals, add colours to food of animal origin' is intended to be used in feed for salmon and trout from an age of six months onwards up to a maximum content of 100 mg ATX/kg complete feed. The product is produced by the telemorph of Phaffia rhodozyma, Xanthophyllomyces dendrorhous, and it is declared to contain 995 g dried inactivated biomass and 5 g ascorbic acid per kg additive. The main active principle of the additive is ATX; however, the FEEDAP Panel noted that some other carotenoids are also present in lower quantities. The minimum ATX concentration is specified to be 5,000 mg per kg additive. The yeast Xanthophyllomyces dendrorhous is considered by EFSA to be suitable for the qualified presumption of safety (QPS) approach to safety assessment; therefore, the use of the production strain in the production of the additive would not raise any safety concern for the target species, the consumers of products from animals fed the additive and the environment. In the absence of a tolerance study with the additive, the FEEDAP Panel cannot conclude on the safety for the target species. In the absence of residue and toxicity data of ATX, no final conclusions on the safety for the consumer can be drawn. The FEEDAP Panel concluded that the additive is irritant to skin and eyes, and a skin and respiratory sensitiser, although exposure by inhalation is likely low. The FEEDAP Panel considers that ATX from the biomass does not pose a significant additional risk to the environment compared with other natural sources of ATX. In absence of adequate evidence, no conclusion can be made on the efficacy of the additive.

Haematococcus pluvialis as a Potential Source of Astaxanthin with Diverse Applications in Industrial Sectors: Current Research and Future Directions

Haematococcus pluvialis, a green microalga, appears to be a rich source of valuable bioactive compounds, such as astaxanthin, carotenoids, proteins, lutein, and fatty acids (FAs). Astaxanthin has a variety of health benefits and is used in the nutraceutical and pharmaceutical industries. Astaxanthin, for example, preserves the redox state and functional integrity of mitochondria and shows advantages despite a low dietary intake. Because of its antioxidant capacity, astaxanthin has recently piqued the interest of researchers due to its potential pharmacological effects, which include anti-diabetic, anti-inflammatory, and antioxidant activities, as well as neuro-, cardiovascular-, ocular, and skin-protective properties. Astaxanthin is a popular nutritional ingredient and a significant component in animal and aquaculture feed. Extensive studies over the last two decades have established the mechanism by which persistent oxidative stress leads to chronic inflammation, which then mediates the majority of serious diseases. This mini-review provides an overview of contemporary research that makes use of the astaxanthin pigment. This mini-review provides insight into the potential of H. pluvialis as a potent antioxidant in the industry, as well as the broad range of applications for astaxanthin molecules as a potent antioxidant in the industrial sector.

Astaxanthin protective barrier and its ability to improve the health in patients with COVID-19

Inflammation acts like a double-edged sword and can be harmful if not appropriately controlled. COVID-19 is created through a novel species of coronavirus SARS-CoV-2 (2019-nCoV). Elevated levels of inflammatory factors such as interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), etc. lead to Acute Respiratory Distress Syndrome (ARDS) and severe complications of infection in the lungs of coronavirus-infected patients. Astaxanthin is a natural and potent carotenoid with powerful antioxidant activity as well as an anti-inflammatory agent that supports good health. The effects of astaxanthin on the regulation of cyclooxygenase-2 (COX-2) pathways and the reduction and suppression of cytokines and other inflammatory agents such as IL-6 and TNF-α have already been identified. Therefore, these unique features can make this natural compound an excellent option to minimize inflammation and its consequences.

The effect of astaxanthin on testicular torsion-detorsion injury in rats - Detailed morphometric evaluation of histological sections

INTRODUCTION

Testicular torsion is one of the conditions of the acute scrotum that requires immediate surgical intervention. If not recognized at time, it can result of ischemic injuries and testicular loss. Restoration of blood flow is essential to save ischemic tissue, but reperfusion itself paradoxically causes further damage. Seaweed and sponges are considered to be the richest source of bioactive compounds that have antioxidant activity. The antioxidant activity of astaxanthin is 10 times higher than zeaxanthin, lutein, canthaxanthin, β-carotene and 100 times higher than α-tocopherol. Since to date there is no drug given to patients with torsion-detorsion testicular injury, we have investigated the effect of this powerful antioxidant.

OBJECTIVE

The aim of this study was to determine the effect of astaxanthin (ASX) on testicular torsion-detorsion injury in rats.

MATERIALS AND METHODS

Thirty-two male Fischer prepubertal rats were divided into 4 groups of 8 individuals. Group 1 underwent sham surgery to determine basal values for histological evaluation. In group 2 (torsion-detorsion group), right testis was twisted at 720° for 90 min. After 90min of reperfusion, the testis was removed. Astaxanthin was administered intraperitoneally at the time of detorsion (group 3) and 45 min after detorsion (group 4) in the treatment groups. Using software ImageJ®, histological morphometric values were measured.

RESULTS

MSTD (mean seminiferous tubule diameter) values increase statistically significantly in ASX groups compared to T/D group. MSLD (mean seminiferous lumen diameter) value was statistically significantly lower in the ASX group 3 compared to the T/D group. Epithelial height was statistically significantly higher in ASX groups compared to the T/D group. Tubular area is statistically significantly higher in ASX group 4, while the luminal area is statistically significantly lower in the ASX group 3 compared to the T/D group. Johnsen score was statistically significantly higher in the ASX groups compared to the T/D group.

DISCUSSION

This is the first scientific paper to study the effects of a single powerful antioxidant on all morphometric parameters. In previous scientific papers, scientists have mainly measured MSTD and the Johnsen score.

CONCLUSION

By measuring all histological morphometric parameters (mean seminiferous tubule diameter, mean seminiferous lumen diameter, epithelial height, tubular area, luminal area, Johnsen score) it can be concluded that astaxanthin has a favorable effect comparing the treated groups to untreated group.

Developmental toxicity of lead in rats after gestational exposure and the protective role of taurine

The present study was conducted to investigate the potential adverse effect of Pb on pregnant Sprague-Dawley rats and their fetuses after maternal exposure, on gestational days (GD) 7-16. The possible protective role of taurine (TA), administered throughout the gestation period (GD 1-20) against Pb toxicity, was also evaluated. Pregnant rats were divided into four groups: Group 1 (control) was given distilled water; Group 2 was exposed to Pb (250 ppm) in drinking water (GD 7-16), whereas Group 3 received TA (50 mg/kg/day) by oral gavage (GD 1-20); Group 4 was exposed to Pb (GD 7-16), whereas pretreated with TA from GD 1 till the end of the gestation period. After termination on GD 20, maternal and embryo-fetal outcomes were evaluated. Blood samples were collected for hematological and biochemical parameters assessment. The results showed that, Pb induced a significant reduction in the maternal body weight, weight gain, uterine and placental weight, in addition to a high incidence of abortion and fetal resorption. Meanwhile, fetuses demonstrated decreased body weight and length, with a high rate of mortality as well as external and skeletal abnormalities. Additionally, Pb induced severe hematological and biochemical alterations in both dams and fetuses. The toxicity of Pb was further emphasized by placental histopathological examination and hepatic DNA fragmentation. Pretreatment with TA greatly attenuated the impact of Pb on both maternal and fetal parameters. Moreover, TA alleviated the incidence of placental damage and hepatic DNA fragmentation. The results highlight the potential prophylaxis role of TA against maternal and developmental Pb toxicity.

Natural antioxidants in diabetes treatment and management: prospects of astaxanthin

Diabetes remains a major health emergency in our entire world, affecting hundreds of millions of people worldwide. In conjunction with its much-dreaded complications (e.g., nephropathy, neuropathy, retinopathy, cardiovascular diseases, etc.) it substantially reduces the quality of life, increases mortality as well as economic burden among patients. Over the years, oxidative stress and inflammation have been highlighted as key players in the development and progression of diabetes and its associated complications. Much research has been devoted, as such, to the role of antioxidants in diabetes. Astaxanthin is a powerful antioxidant found mostly in marine organisms. Over the past years, several studies have demonstrated that astaxanthin could be useful in the treatment and management of diabetes. It has been shown to protect β-cells, neurons as well as several organs including the eyes, kidney, liver, etc. against oxidative injuries experienced during diabetes. Furthermore, it improves glucose and lipid metabolism along with cardiovascular health. Its beneficial effects are exerted through multiple actions on cellular functions. Considering these and the fact that foods and natural products with biological and pharmacological activities are of much interest in the 21st-century food and drug industry, astaxanthin has a bright prospect in the management of diabetes and its complications.

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.

Astaxanthin in Liver Health and Disease: A Potential Therapeutic Agent

Astaxanthin is a carotenoid derived from oxygen-containing non-vitamin A sources and is mainly obtained from marine organisms. Studies have demonstrated that astaxanthin is a natural antioxidant product and it is widely used in the fields of medicine, health-care products and cosmetics. Studies have shown that astaxanthin has important preventive and therapeutic effects on liver fibrosis, non-alcoholic fatty liver, liver cancer, drug and ischemia-induced liver injury, and its mechanism is related to antioxidant and anti-inflammatory activities, and the regulation of multiple signaling pathways. In this review, we discuss the latest data on astaxanthin in the prevention and treatment of liver diseases. An understanding of the structure, source and mechanism of action of astaxanthin in the body would not only provide a theoretical basis for its clinical application but could also have important significance in screening and improving related compounds for the treatment of liver diseases.

Safety assessment of astaxanthin from Haematococcus pluvialis: Acute toxicity, genotoxicity, distribution and repeat-dose toxicity studies in gestation mice

Natural astaxanthin is the strongest antioxidant ever discovered, with many biological functions, and it is widely used in the fields of health food and biomedical research. In the present study, we aimed to investigate the plasma concentration, distribution and safety of astaxanthin from Haematococcus pluvialis in pregnant mice. In the acute studies, the oral LD₅₀ of astaxanthin was greater than 20 g/kg·bw. In mouse bone marrow micronucleus test, 10 g/kg·bw astaxanthin did not cause damage to chromosomes and mitotic apparatus of pregnant mice. After treatment with a single dose of 500 mg/kg·bw astaxanthin, the concentration of astaxanthin in plasma reached the maximum at 8 h (55.7 μg/L), which was completely metabolized after 48 h. In the repeat-dose toxicity test, 100, 250 and 500 mg/kg·bw astaxanthin showed no abnormalities in terms of body and organ weight as well as hematological and biochemical parameters in clinical observation throughout the pregnancy. During pregnancy, the liver accumulated the highest content of astaxanthin, while the eye exhibited the least. The results indicated that administration of astaxanthin from H. pluvialis throughout pregnancy had no adverse effect on mice.

Trends in use, pharmacology, and clinical applications of emerging herbal nutraceuticals

The nutraceuticals market is vast, encompassing many different products with inconsistent levels of evidence available to support their use. This overview represents a Western perspective of the nutraceuticals market, with a brief comparison with that in China, as an illustration of how individual health supplements increase and decrease in popularity in regional terms. Recent changes in sales patterns, mainly taken from the US market, are summarized and a selection of five newer products, which have not been subject to extensive recent review are profiled: astaxanthin, a carotenoid found in red algae, seafood, salmon and trout, as an antioxidant; cannabidiol, a non-euphoric marijuana ingredient used as mood enhancer and for painful/inflammatory conditions; modified extracts of ginseng used in new indications including dementia and space travel; monk fruit, a non-sugar high intensity sweetener and nigella seed, a popular food ingredient and Asian medicine, which has experienced an extraordinary rise in sales recently. LINKED ARTICLES: This article is part of a themed section on The Pharmacology of Nutraceuticals. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v177.6/issuetoc.

Astaxanthin-antioxidant impact on excessive Reactive Oxygen Species generation induced by ischemia and reperfusion injury

Oxidative stress induced by Reactive Oxygen Species (ROS) was shown to be involved in the pathogenesis of chronic diseases such as cardiovascular pathologies. Particularly, oxidative stress has proved to mediate abnormal platelet function and dysfunctional endothelium-dependent vasodilatation representing a key factor in the progression of ischemic injuries. Antioxidants like carotenoids have been suggested to contribute in their prevention and treatment. Astaxanthin, a xanthophyll carotenoid produced naturally and synthetically, shows interesting antioxidant and anti-inflammatory properties. In vivo studies applying different models of induced ischemia and reperfusion (I/R) injury confirm astaxanthin's protective action after oral or intravenous administration. However, some studies have shown some limitations after oral administration such as low stability, bioavailability and bioefficacy, revealing a need for the implementation of new biomaterials to act as astaxanthin vehicles in vivo. Here, a brief overview of the chemical characteristics of astaxanthin, the carrier systems developed for overcoming its delivery drawbacks and the animal studies showing its potential effect to treat I/R injury are presented.