Astaxanthin protects beta-cells against glucose toxicity in diabetic db/db mice

Astaxanthin: a nature's versatile compound utilized for diverse applications and its therapeutic effects

Astaxanthin (ASTX), red-colored xanthophyll, also known as the "king of carotenoids" exhibits a strong antioxidant property that can be naturally found in green algae Haematococcus pluvialis, red yeast Phaffia rhodozyma, and various aquatic species including salmon, krill, trout, and fish eggs. Due to their strong antioxidant qualities, ASTX nanoparticles may be crucial in fighting against phytotoxicity caused by heavy metal ions. Similarly, it may also reduce the uptake of heavy metal, i.e. cadmium, and translocation by improving the morpho-physiological profiles of plants. Furthermore, it can also have the ability to scavenge free radicals, therefore, it can protect plants from reactive oxygen species (ROS). Implementing ASTX nanoparticles on crops can also help to achieve higher food production while minimizing toxic effects. Additionally, it can also possess several therapeutic activities including anti-cancerous, anti-diabetic, antioxidant, anti-aging, anti-inflammation, hepatoprotective, and cardiovascular, etc. that can be beneficial to treat various types of diseases in humans and animals. Recently, it has gained more interest in food, agriculture, aquaculture, neutraceuticals, and pharmaceutical industries due to its wide range of applications including food-coloring agents, food supplements, and strong antioxidant property that helps in skin protection, and boosts immune function. However, ASTX possesses poor water solubility and chemical stability so the implementation of ASTX on human health is facing various issues. Therefore, nanoencapsulation of ASTX is very crucial to improve its chemical stability and solubility, ultimately leading to its bioavailability and bioaccessibility. Recently, ASTX has been commercially available with specific dosages in the market mainly in the form of tablets, gels, powders, creams, syrups, etc. The current review mainly highlights the present state of ASTX nanoparticle applications in various fields explaining its natural and synthetic sources, extraction methods, chemical structure, stability, nanoformulations, nano encapsulation, and various commercial aspects.

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

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

The Effects of Astaxanthin on Metabolic Syndrome: A Comprehensive Review

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

Astaxanthin has a beneficial influence on pain-related symptoms and opioid-induced hyperalgesia in mice with diabetic neuropathy-evidence from behavioral studies

BACKGROUND

The treatment of painful diabetic neuropathy is still a clinical problem. The aim of this study was to determine whether astaxanthin, a substance that inhibits mitogen-activated protein kinases, activates nuclear factor erythroid 2-related factor 2 and influences N-methyl-D-aspartate receptor, affects nociceptive transmission in mice with diabetic neuropathy.

METHODS

The studies were performed on streptozotocin-induced mouse diabetic neuropathic pain model. Single intrathecal and intraperitoneal administrations of astaxanthin at various doses were conducted in both males and females. Additionally, repeated twice-daily treatment with astaxanthin (25 mg/kg) and morphine (30 mg/kg) were performed. Hypersensitivity was evaluated with von Frey and cold plate tests.

RESULTS

This behavioral study provides the first evidence that in a mouse model of diabetic neuropathy, single injections of astaxanthin similarly reduce tactile and thermal hypersensitivity in both male and female mice, regardless of the route of administration. Moreover, repeated administration of astaxanthin slightly delays the development of morphine tolerance and significantly suppresses the occurrence of opioid-induced hyperalgesia, although it does not affect blood glucose levels, body weight, or motor coordination. Surprisingly, astaxanthin administered repeatedly produces a better analgesic effect when administered alone than in combination with morphine, and its potency becomes even more pronounced over time.

CONCLUSIONS

These behavioral results provide a basis for further evaluation of the potential use of astaxanthin in the clinical treatment of diabetic neuropathy and suggest that the multidirectional action of this substance may have positive effects on relieving neuropathic pain in diabetes.

Protection of pancreatic beta cells against high glucose-induced toxicity by astaxanthin-s-allyl cysteine diester: alteration of oxidative stress and apoptotic-related protein expression

Purpose: High glucose (HG)-induced oxidative stress is associated with apoptosis in pancreatic β-cells. The protective effect of astaxanthin-s-allyl cysteine diester (AST-SAC) against HG-induced oxidative stress in pancreatic β-cells (βTC-tet cell line) in in vitro was studied.Materials and Methods: βTC-tet cell line was exposed to HG in the presence and absence of AST-SAC. Various parameters such as cell viability, reactive oxygen species generation, mitochondrial membrane potential, DNA fragmentation and expression of proteins involved in apoptosis [p53, B-cell lymphoma 2 (Bcl-2), Bcl-2 associated X (Bax), cytochrome c and caspase 3] were studied.Results: Pre-treatment of βTC-tet cells with AST-SAC (4, 8 and 12 μg/ml) in the presence of HG (25 mM) protected the viability of the cells in a dose-dependent manner. AST-SAC treatment mitigated the oxidative stress thereby preventing the mitochondrial dysfunction, DNA damage and apoptosis in βTC-tet cells against HG toxicity. Treatment with AST-SAC prevented the increased expression of p53 under HG conditions. Further, AST-SAC treatment maintained the level of pro-apoptotic (Bax, cleaved caspase-3 and cytochrome c) and anti-apoptotic (Bcl-2) proteins to that of the control level under HG exposed conditions in βTC-tet cells.Conclusion: Altogether, AST-SAC alleviated HG-induced oxidative damage and apoptosis in pancreatic β-cells by enhancing the antioxidant status and altering apoptotic-related protein expression.

Astaxanthin targets IL-6 and alleviates the LPS-induced adverse inflammatory response of macrophages

Numerous natural compounds are recognized for their anti-inflammatory properties attributed to antioxidant effects and the modulation of key inflammatory factors. Among them, astaxanthin (AST), a potent carotenoid antioxidant, remains relatively underexplored regarding its anti-inflammatory mechanisms and specific molecular targets. In this study, human monocytic leukemia cell-derived macrophages (THP-1) were selected as experimental cells, and lipopolysaccharides (LPS) served as inflammatory stimuli. Upon LPS treatment, the oxidative stress was significantly increased, accompanied by remarkable cellular damage. Moreover, LPSs escalated the expression of inflammation-related molecules. Our results demonstrate that AST intervention could effectively alleviate LPS-induced oxidative stress, facilitate cellular repair, and significantly attenuate inflammation. Further exploration of the anti-inflammatory mechanism revealed AST could substantially inhibit NF-κB translocation and activation, and mitigate inflammatory factor production by hindering NF-κB through the antioxidant mechanism. We further confirmed that AST exhibited protective effects against cell damage and reduced the injury from inflammatory cytokines by activating p53 and inhibiting STAT3. In addition, utilizing network pharmacology and in silico calculations based on molecular docking, molecular dynamics simulation, we identified interleukin-6 (IL-6) as a prominent core target of AST anti-inflammation, which was further validated by the RNA interference experiment. This IL-6 binding capacity actually enabled AST to curb the positive feedback loop of inflammatory factors, averting the onset of possible inflammatory storms. Therefore, this study offers a new possibility for the application and development of astaxanthin as a popular dietary supplement of anti-inflammatory or immunomodulatory function.

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.

Biotechnological strategies overcoming limitations to H. pluvialis-derived astaxanthin production and Morocco's potential

Haematococcus pluvialis is the richest source of natural astaxanthin, but the production of H. pluvialis-derived astaxanthin is usually limited by its slow cell proliferation and astaxanthin accumulation. Efforts to enhance biomass productivity, astaxanthin accumulation, and extraction are ongoing. This review highlights different approaches that have previously been studied in microalgal species for enhanced biomass productivity, as well as optimized methods for astaxanthin accumulation and extraction, and how these methods could be combined to bypass the challenges limiting natural astaxanthin production, particularly in H. pluvialis, at all stages (biomass production, and astaxanthin accumulation and extraction). Biotechnological approaches, such as overexpressing low CO2 inducible genes, utilizing complementary carbon sources, CRISPR-Cas9 bioengineering, and the use of active compounds, for biomass productivity are outlined. Direct astaxanthin extraction from H. pluvialis zoospores and Morocco's potential for microalgal-based astaxanthin production are equally discussed. This review emphasizes the need to engineer an optimized H. pluvialis-derived astaxanthin production system combining two or more of these strategies for increased growth, and astaxanthin productivity, to compete in the larger, lower-priced market in aquaculture and nutraceutical sectors.

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

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

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

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

Astaxanthin attenuated the stress-induced intestinal motility disorder via altering the gut microbiota

Gut microbiota and short-chain fatty acids (SCFAs) are recognized as key factors in the pathophysiology of irritable bowel syndrome. Astaxanthin is a carotenoid with strong antioxidant and anti-inflammatory activities. In this study, we examined the effects of astaxanthin on gut microbiota-, SCFAs-, and corticotropin-releasing factor (CRH)-induced intestinal hypermotility. Male Wistar rats (n=12 per group) were fed a diet with or without 0. 02% (w/w) astaxanthin for four weeks and CRH or saline was administered intravenously. The number of fecal pellets was counted 2 h after injection. Then the rats were sacrificed, and the cecal content were collected 3 h after injection. The number of feces was significantly increased by CRH injection in the control group (2.0 vs. 6.5; p=0.028), but not in the astaxanthin group (1.0 vs. 2.2; p=0.229) (n=6 per group). The cecal microbiota in the astaxanthin group was significantly altered compared with that in the control group. The concentrations of acetic acid (81.1 μmol/g vs. 103.9 μmol/g; p=0.015) and butyric acid (13.4 μmol/g vs. 39.2 μmol/g; p<0.001) in the astaxanthin group were significantly lower than that in the control group (n=12 per group). Astaxanthin attenuates CRH-induced intestinal hypermotility and alters the composition of gut microbiota and SCFAs.

Therapeutic Potentials of Microalgae and Their Bioactive Compounds on Diabetes Mellitus

Diabetes mellitus is a metabolic disorder characterized by hyperglycemia due to impaired insulin secretion, insulin resistance, or both. Oxidative stress and chronic low-grade inflammation play crucial roles in the pathophysiology of diabetes mellitus. There has been a growing interest in applying natural products to improve metabolic derangements without the side effects of anti-diabetic drugs. Microalgae biomass or extract and their bioactive compounds have been applied as nutraceuticals or additives in food products and health supplements. Several studies have demonstrated the therapeutic effects of microalgae and their bioactive compounds in improving insulin sensitivity attributed to their antioxidant, anti-inflammatory, and pancreatic β-cell protective properties. However, a review summarizing the progression in this topic is lacking despite the increasing number of studies reporting their anti-diabetic potential. In this review, we gathered the findings from in vitro, in vivo, and human studies to discuss the effects of microalgae and their bioactive compounds on diabetes mellitus and the mechanisms involved. Additionally, we discuss the limitations and future perspectives of developing microalgae-based compounds as a health supplement for diabetes mellitus. In conclusion, microalgae-based supplementation has the potential to improve diabetes mellitus and be applied in more clinical studies in the future.

Hypoglycaemic Molecules for the Management of Diabetes Mellitus from Marine Sources

Diabetes mellitus (DM) is a chronic metabolic disorder recognized as a major health problem globally. A defective insulin activity contributes to the prevalence and expansion of DM. Treatment of DM is often hampered by limited options of conventional therapies and adverse effects associated with existing procedures. This has led to a spike in the exploration for potential therapeutic agents from various natural resources for clinical applications. The marine environment is a huge store of unexplored diversity of chemicals produced by a multitude of organisms. To date, marine microorganisms, microalgae, macroalgae, corals, sponges, and fishes have been evaluated for their anti-diabetic properties. The structural diversity of bioactive metabolites discovered has shown promising hypoglycaemic potential through in vitro and in vivo screenings via various mechanisms of action, such as PTP1B, α-glucosidase, α-amylase, β-glucosidase, and aldose reductase inhibition as well as PPAR alpha/gamma dual agonists activities. On the other hand, hypoglycaemic effect is also shown to be exerted through the balance of antioxidants and free radicals. This review highlights marine-derived chemicals with hypoglycaemic effects and their respective mechanisms of action in the management of DM in humans.

Astaxanthin as a Potent Antioxidant for Promoting Bone Health: An Up-to-Date Review

In recent years, bone loss and its associated diseases have become a significant public health concern due to increased disability, morbidity, and mortality. Oxidative stress and bone loss are correlated, where oxidative stress suppresses osteoblast activity, resulting in compromised homeostasis between bone formation and resorption. This event causes upregulation of bone remodeling turnover rate with an increased risk of fractures and bone loss. Therefore, supplementation of antioxidants can be proposed to reduce oxidative stress, facilitate the bone remodeling process, suppress the initiation of bone diseases, and improve bone health. Astaxanthin (3,3'-dihydroxy-4-4'-diketo-β-β carotene), a potent antioxidant belonging to the xanthophylls family, is a potential ROS scavenger and could be a promising therapeutic nutraceutical possessing various pharmacological properties. In bone, astaxanthin enhances osteoblast differentiation, osteocytes numbers, and/or differentiation, inhibits osteoclast differentiation, cartilage degradation markers, and increases bone mineral density, expression of osteogenic markers, while reducing bone loss. In this review, we presented the up-to-date findings of the potential anabolic effects of astaxanthin on bone health in vitro, animal, and human studies by providing comprehensive evidence for its future clinical application, especially in treating bone diseases.

Formulation Approaches to Crystalline Status Modification for Carotenoids: Impacts on Dissolution, Stability, Bioavailability, and Bioactivities

Carotenoids, including carotenes and xanthophylls, have been identified as bioactive ingredients in foods and are considered to possess health-promoting effects. From a biopharmaceutical perspective, several physicochemical characteristics, such as scanty water solubility, restricted dissolution, and susceptibility to oxidation may influence their oral bioavailability and eventually, their effectiveness. In this review, we have summarized various formulation approaches that deal with the modification of crystalline status for carotenoids, which may improve their physicochemical properties, oral absorption, and biological effects. The mechanisms involving crystalline alteration and the typical methods for examining crystalline states in the pharmaceutical field have been included, and representative formulation approaches are introduced to unriddle the mechanisms and effects more clearly.

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.

Carotenoids in Drug Discovery and Medicine: Pathways and Molecular Targets Implicated in Human Diseases

Carotenoids are isoprenoid-derived natural products produced in plants, algae, fungi, and photosynthetic bacteria. Most animals cannot synthesize carotenoids because the biosynthetic machinery to create carotenoids de novo is absent in animals, except arthropods. Carotenoids are biosynthesized from two C20 geranylgeranyl pyrophosphate (GGPP) molecules made from isopentenyl pyrophosphate (IPP) and dimethylallyl pyrophosphate (DMAPP) via the methylerythritol 4-phosphate (MEP) route. Carotenoids can be extracted by a variety of methods, including maceration, Soxhlet extraction, supercritical fluid extraction (SFE), microwave-assisted extraction (MAE), accelerated solvent extraction (ASE), ultrasound-assisted extraction (UAE), pulsed electric field (PEF)-assisted extraction, and enzyme-assisted extraction (EAE). Carotenoids have been reported to exert various biochemical actions, including the inhibition of the Akt/mTOR, Bcl-2, SAPK/JNK, JAK/STAT, MAPK, Nrf2/Keap1, and NF-κB signaling pathways and the ability to increase cholesterol efflux to HDL. Carotenoids are absorbed in the intestine. A handful of carotenoids and carotenoid-based compounds are in clinical trials, while some are currently used as medicines. The application of metabolic engineering techniques for carotenoid production, whole-genome sequencing, and the use of plants as cell factories to produce specialty carotenoids presents a promising future for carotenoid research. In this review, we discussed the biosynthesis and extraction of carotenoids, the roles of carotenoids in human health, the metabolism of carotenoids, and carotenoids as a source of drugs and supplements.

Nanocarrier System: State-of-the-Art in Oral Delivery of Astaxanthin

Astaxanthin (3,3′-dihydroxy-4,4′-diketo-β-β carotene), which belongs to the xanthophyll class, has shown potential biological activity in in vitro and in vivo models including as a potent antioxidant, anti-lipid peroxidation and cardiovascular disease prevention agent. It is mainly extracted from an alga, Haematococcus pluvialis. As a highly lipid-soluble carotenoid, astaxanthin has been shown to have poor oral bioavailability, which limits its clinical applications. Recently, there have been several suggestions and the development of various types of nano-formulation, loaded with astaxanthin to enhance their bioavailability. The employment of nanoemulsions, liposomes, solid lipid nanoparticles, chitosan-based and PLGA-based nanoparticles as delivery vehicles of astaxanthin for nutritional supplementation purposes has proven a higher oral bioavailability of astaxanthin. In this review, we highlight the pharmacological properties, pharmacokinetics profiles and current developments of the nano-formulations of astaxanthin for its oral delivery that are believed to be beneficial for future applications. The limitations and future recommendations are also discussed in this review.

Development of Fermented Shrimp Shell Product with Hypoglycemic and Hypolipidemic Effects on Diabetic Rats

In 2020, approximately 9.3 billion tons of crustaceans were consumed, and 45–48% of shrimp shell (SS) by-products were discarded as waste. In this study, the SS of Litopenaeus vannamei was fermented by Lactobacillus plantarum LV33204, Stenotrophomonas maltophilia LV2122 (strong proteolytic activity), and Aeromonas dhakensis LV1111 (chitin-degrading activity), and the optimal fermentation conditions of liquid-fermented SS was established. Contents of total peptide, astaxanthin, and total phenolic content of the fermented SS were significantly higher than that of unfermented SS. In the presence of fermented SS, glucose uptake and insulin resistance of TNF-α-stimulated FL83B hepatocytes were markedly improved. Furthermore, daily oral supplement of fermented SS to streptozotocin (STZ)/nicotinamide (NA)-induced diabetic rats for 7 weeks significantly reduced plasma glucose and insulin resistance. Meanwhile, ingestion of fermented SS might enhance hepatic catabolism of glucose by increasing hexokinase and glucose-6-phosphate dehydrogenase activity and decreasing glucose-6-phosphatase activity. In addition, the fermented SS downregulated plasma total cholesterol (TG), triglycerides (TCs), low-density lipoprotein cholesterol (LDL-C), liver TG, and TC and lipid peroxidation levels in diabetic rats. In conclusion, a biorefinery process for waste SS was established through mixed strain fermentation. The in vitro and in vivo data reveal that the fermented SS is a promising functional food for the management of diabetic hyperglycemia and hyperlipidemia.

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.

The Putative Role of Astaxanthin in Neuroinflammation Modulation: Mechanisms and Therapeutic Potential

Neuroinflammation is a protective mechanism against insults from exogenous pathogens and endogenous cellular debris and is essential for reestablishing homeostasis in the brain. However, excessive prolonged neuroinflammation inevitably leads to lesions and disease. The use of natural compounds targeting pathways involved in neuroinflammation remains a promising strategy for treating different neurological and neurodegenerative diseases. Astaxanthin, a natural xanthophyll carotenoid, is a well known antioxidant. Mounting evidence has revealed that astaxanthin is neuroprotective and has therapeutic potential by inhibiting neuroinflammation, however, its functional roles and underlying mechanisms in modulating neuroinflammation have not been systematically summarized. Hence, this review summarizes recent progress in this field and provides an update on the medical value of astaxanthin. Astaxanthin modulates neuroinflammation by alleviating oxidative stress, reducing the production of neuroinflammatory factors, inhibiting peripheral inflammation and maintaining the integrity of the blood-brain barrier. Mechanistically, astaxanthin scavenges radicals, triggers the Nrf2-induced activation of the antioxidant system, and suppresses the activation of the NF-κB and mitogen-activated protein kinase pathways. With its good biosafety and high bioavailability, astaxanthin has strong potential for modulating neuroinflammation, although some outstanding issues still require further investigation.

The pharmaco-therapy potential of astaxanthin: human and animal targeting roles

The recent pandemic stress and the impacts of climatic changes on humans’ and animals’ health status and well-being resulted in severe drawbacks. Initially, stress-induced oxidation resulting from the generation of free radicals leading to the impairment of cellular function and a high possibility of attack with infection. Astaxanthin is a bioactive material derived from fish, crustaceans, and algae with high antioxidative potential. Astaxanthin is a lipid-soluble carotenoid that can easily cross through the cellular membrane layers to catch the reactive oxygen metabolites. Astaxanthin also has pigmentation properties making it suitable for pharmaceutical, cosmetic, nutraceutical, agriculture, and aquaculture sectors. Recently, astaxanthin is suggested as a natural scavenger for free radicals induced by COVID-19. Besides, using astaxanthin as antioxidative and immunostimulant agents is well-reported in several clinical studies. The output of these investigations should be simplified and presented to the scientific community to utilize the available information and fill the gap of knowledge. Also, it is necessary to update the researchers with the recent recommendations of applying astaxanthin in vivo and in vitro to help in proposing new horizons for engaging natural antioxidative agents to protect human and animal health. Herein, this review article tackled the nature, sources, potential roles, applicable sides, and availability of astaxanthin to fortify the scientific community with the required knowledge for further research efforts.

Astaxanthin as a Modulator of Nrf2, NF-κB, and Their Crosstalk: Molecular Mechanisms and Possible Clinical Applications

Astaxanthin (AST) is a dietary xanthophyll predominantly found in marine organisms and seafood. Due to its unique molecular features, AST has an excellent antioxidant activity with a wide range of applications in the nutraceutical and pharmaceutical industries. In the past decade, mounting evidence has suggested a protective role for AST against a wide range of diseases where oxidative stress and inflammation participate in a self-perpetuating cycle. Here, we review the underlying molecular mechanisms by which AST regulates two relevant redox-sensitive transcription factors, such as nuclear factor erythroid 2-related factor 2 (Nrf2) and nuclear factor κB (NF-κB). Nrf2 is a cellular sensor of electrophilic stress that coordinates the expression of a battery of defensive genes encoding antioxidant proteins and detoxifying enzymes. Likewise, NF-κB acts as a mediator of cellular stress and induces the expression of various pro-inflammatory genes, including those encoding cytokines, chemokines, and adhesion molecules. The effects of AST on the crosstalk between these transcription factors have also been discussed. Besides this, we summarize the current clinical studies elucidating how AST may alleviate the etiopathogenesis of oxidative stress and inflammation.

Nanotechnology-Abetted Astaxanthin Formulations in Multimodel Therapeutic and Biomedical Applications

Astaxanthin (AXT) is one of the most important fat-soluble carotenoids that have abundant and diverse therapeutic applications namely in liver disease, cardiovascular disease, cancer treatment, protection of the nervous system, protection of the skin and eyes against UV radiation, and boosting the immune system. However, due to its intrinsic reactivity, it is chemically unstable, and therefore, the design and production processes for this compound need to be precisely formulated. Nanoencapsulation is widely applied to protect AXT against degradation during digestion and storage, thus improving its physicochemical properties and therapeutic effects. Nanocarriers are delivery systems with many advantages─ease of surface modification, biocompatibility, and targeted drug delivery and release. This review discusses the technological advancement in nanocarriers for the delivery of AXT through the brain, eyes, and skin, with emphasis on the benefits, limitations, and efficiency in practice.

Mechanistic role of astaxanthin derived from shrimp against certain metabolic disorders

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

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.

Inhibitory Effects of Astaxanthin on CML-HSA-Induced Inflammatory and RANKL-Induced Osteoclastogenic Gene Expression in RAW 264.7 Cells

Objective: Elevated levels of serum N^ε-carboxymethyllysine (CML), a well-known advanced glycation end-product (AGE), were observed in patients with inflammation or osteoporosis. Astaxanthin was reported to possess anti-inflammatory and antioxidant effects. In the present study, we investigated the effects of commercially available dietary supplement AstaReal ACT^R (ASR) capsule content as astaxanthin on CML-HSA-induced inflammatory and receptor activator of nuclear factor-kappa-Β ligand (RANKL)-induced osteoclastogenic gene expression. Methods: RAW 264.7 murine macrophage cells were stimulated with CML-HSA to trigger inflammatory gene expression and treated with either a vehicle control or varied concentrations of astaxanthin. Inflammatory gene expression was measured using an enzyme-linked immunosorbent assay (ELISA) or qPCR. We triggered osteoclastogenesis using RANKL, and osteoclastogenic gene expression was measured through tartrate-resistant acid phosphatase (TRAP) activity, staining, immunofluorescence, and qPCR analyses. Results: CML-HSA showed a stimulatory effect on inflammatory gene expression, and astaxanthin reduced the expression by at least two-fold. The levels of autoinflammatory gene expression were reduced by astaxanthin. The RANKL-induced osteoclastogenesis was significantly inhibited by astaxanthin, with reductions in the activation of nuclear factor-κB (NF-κB), the expression of NFATc1 (nuclear factor of activated T cells 1), multinucleated cell formation, and the expression of mature osteoclast marker genes. Conclusion: Astaxanthin has potential as a remedy for CML-HSA-induced inflammation and RANKL-induced excessive bone loss.

Maintaining Effective Beta Cell Function in the Face of Metabolic Syndrome-Associated Glucolipotoxicity-Nutraceutical Options

In people with metabolic syndrome, episodic exposure of pancreatic beta cells to elevated levels of both glucose and free fatty acids (FFAs)-or glucolipotoxicity-can induce a loss of glucose-stimulated insulin secretion (GSIS). This in turn can lead to a chronic state of glucolipotoxicity and a sustained loss of GSIS, ushering in type 2 diabetes. Loss of GSIS reflects a decline in beta cell glucokinase (GK) expression associated with decreased nuclear levels of the pancreatic and duodenal homeobox 1 (PDX1) factor that drives its transcription, along with that of Glut2 and insulin. Glucolipotoxicity-induced production of reactive oxygen species (ROS), stemming from both mitochondria and the NOX2 isoform of NADPH oxidase, drives an increase in c-Jun N-terminal kinase (JNK) activity that promotes nuclear export of PDX1, and impairs autocrine insulin signaling; the latter effect decreases PDX1 expression at the transcriptional level and up-regulates beta cell apoptosis. Conversely, the incretin hormone glucagon-like peptide-1 (GLP-1) promotes nuclear import of PDX1 via cAMP signaling. Nutraceuticals that quell an increase in beta cell ROS production, that amplify or mimic autocrine insulin signaling, or that boost GLP-1 production, should help to maintain GSIS and suppress beta cell apoptosis in the face of glucolipotoxicity, postponing or preventing onset of type 2 diabetes. Nutraceuticals with potential in this regard include the following: phycocyanobilin-an inhibitor of NOX2; agents promoting mitophagy and mitochondrial biogenesis, such as ferulic acid, lipoic acid, melatonin, berberine, and astaxanthin; myo-inositol and high-dose biotin, which promote phosphatidylinositol 3-kinase (PI3K)/Akt activation; and prebiotics/probiotics capable of boosting GLP-1 secretion. Complex supplements or functional foods providing a selection of these agents might be useful for diabetes prevention.

[Therapeutic mechanism of natural astaxanthin against renal clear cell carcinoma based on network pharmacology and bioinformatics]

OBJECTIVE

To explore the molecular mechanism by which natural astaxanthin (AST) inhibits renal clear cell carcinoma (KIRC) based on network pharmacology and bioinformatics.

METHODS

PharmMapper database was used to retrieve the targets of natural astaxanthin, and TCGA database was used to identify the differentially expressed genes (DEGs) in KIRC and adjacent tissues. The target genes of AST was analyzed using Cytoscape software to construct the "drug-target" network diagram. The visual protein-protein interaction (PPI) network was constructed using String database, and GO enrichment analysis of the core targets was performed. Single gene bioinformatics was performed to verify the screened core target of AST, namely placental growth factor (PGF). The effect of natural AST on the viability of KIRC cells was tested using CCK-8 method, and the binding between natural AST and PGF was assessed with molecular docking technology. The effect of natural AST on the mRNA and protein expression of the target genes was analyzed using RT-qPCR and Western blotting.

RESULTS

We identified 278 candidate targets of AST, 1081 KIRC-related targets, and 7 core targets involved in the therapeutic mechanism of AST against KIRC. Among these 7 core targets, PGF showed significantly upregulated expression in KIRC (P < 0.001) in correlation with a poor prognosis (HR=1.37, P=0.043). Molecular docking showed that the binding energy of AST and PGF was -5.43 kcal/mol. CCK-8 assay showed that AST at the concentration of 50 μmol/L was capable of inhibiting the proliferation of KIRC cells, and a higher concentration resulted in a stronger inhibitory effect. The results of RT-qPCR and Western blotting showed that AST treatment significantly reduced the expression of PGF at both the mRNA and protein levels in KIRC cells.

CONCLUSION

Natural AST can suppress the proliferation of KIRC and inhibit the expression of PGF in the cells.

The Beneficial Effects of Astaxanthin on Glucose Metabolism and Modified Low-Density Lipoprotein in Healthy Volunteers and Subjects with Prediabetes

Astaxanthin (ASTX) is an antioxidant agent. Recently, its use has been focused on the prevention of diabetes and atherosclerosis. We examined the effects of astaxanthin supplementation for 12 weeks on glucose metabolism, glycemic control, insulin sensitivity, lipid profiles and anthropometric indices in healthy volunteers including subjects with prediabetes with a randomized, placebo-controlled trial. Methods: We enrolled 53 subjects who met our inclusion criteria and administered them with 12 mg astaxanthin or a placebo once daily for 12 weeks. Subsequently, their HbA1c levels, lipid profiles and biochemical parameters were determined. The participants also underwent a 75 g oral glucose tolerance test (OGTT), vascular endothelial function test and measurement of the visceral fat area. Results: After astaxanthin supplementation for 12 weeks, glucose levels after 120 min in a 75 g OGTT significantly decreased compared to those before supplementation. Furthermore, the levels of HbA1c (5.64 ± 0.33 vs. 5.57 ± 0.39%, p < 0.05), apo E (4.43 ± 1.29 vs. 4.13 ± 1.24 mg/dL, p < 0.05) and malondialdehyde-modified low-density lipoprotein (87.3 ± 28.6 vs. 76.3 ± 24.6 U/L, p < 0.05) were also reduced, whereas total cholesterol (TC), triglyceride (TG) and high-density lipoprotein-C (HDL-C) levels were unaltered. The Matuda index, which is one of the parameters of insulin resistance, was improved in the ASTX group compared to that before supplementation. Conclusions: our results suggest that ASTX may have preventive effects against diabetes and atherosclerosis and may be a novel complementary treatment option for the prevention of diabetes in healthy volunteers, including subjects with prediabetes, without adverse effects.

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

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

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

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

Effects of astaxanthin in animal models of obesity-associated diseases: A systematic review and meta-analysis

BACKGROUND AND AIM

Obesity is a major risk factor for several diseases, including metabolic syndrome (MetS), non-alcoholic fatty liver disease (NAFLD) and type 2 diabetes (T2D). The use of natural products, such as astaxanthin (ASX), a potent antioxidant compound produced by the freshwater green microalga Haematococcus pluvialis, has gained particular interest to reduce oxidative stress and inflammation, and to improve redox status, often associated with obesity. A systematic review and meta-analysis was performed to comprehensively examine the effects of ASX in animal models of diet induced obesity-associated diseases in order to inform the design of future human clinical studies for ASX use as supplement or nutraceutical.

METHODS

Cinahl, Cochraine, MEDLINE, Scopus and Web of Science were searched for English-language manuscripts published between January 2000 and April 2020 using the following key words: astaxanthin, obesity, non-alcoholic fatty liver disease, diabetes mellitus type 2, NAFLD and metabolic.

RESULTS

Seventeen eligible articles, corresponding to 21 animal studies, were included in the final quantitative analysis. ASX, at different concentrations and administered for different length of time, induced a significant reduction in adipose tissue weight (P = 0.05) and systolic blood pressure (P < 0.0001) in control animals. In animal models of T2D, ASX significantly reduced serum glucose levels (P = 0.04); whereas it improved several disease biomarkers in the blood (e.g. cholesterol, triglycerides, ALT and AST, P < 0.10), and reduced liver (P = 0.0002) and body weight (P = 0.11), in animal models of NAFLD.

CONCLUSIONS

Supplementation of ASX in the diet has positive effects on symptoms associated with obesity related diseases in animals, by having lipid-lowering, hypo-insulin and hypoglycaemic capacity, protecting organs from oxidative stress and mitigating the immune system, as suggested in this review.

Mitochondrion as a Target of Astaxanthin Therapy in Heart Failure

Mitochondria are considered to be important organelles in the cell and play a key role in the physiological function of the heart, as well as in the pathogenesis and development of various heart diseases. Under certain pathological conditions, such as cardiovascular diseases, stroke, traumatic brain injury, neurodegenerative diseases, muscular dystrophy, etc., mitochondrial permeability transition pore (mPTP) is formed and opened, which can lead to dysfunction of mitochondria and subsequently to cell death. This review summarizes the results of studies carried out by our group of the effect of astaxanthin (AST) on the functional state of rat heart mitochondria upon direct addition of AST to isolated mitochondria and upon chronic administration of AST under conditions of mPTP opening. It was shown that AST exerted a protective effect under all conditions. In addition, AST treatment was found to prevent isoproterenol-induced oxidative damage to mitochondria and increase mitochondrial efficiency. AST, a ketocarotenoid, may be a potential mitochondrial target in therapy for pathological conditions associated with oxidative damage and mitochondrial dysfunction, and may be a potential mitochondrial target in therapy for pathological conditions.

Potential Glioprotective Strategies Against Diabetes-Induced Brain Toxicity

Astrocytes are crucial for the maintenance of brain homeostasis by actively participating in the metabolism of glucose, which is the main energy substrate for the central nervous system (CNS), in addition to other supportive functions. More specifically, astrocytes support neurons through the metabolic coupling of synaptic activity and glucose utilization. As such, diabetes mellitus (DM) and consequent glucose metabolism disorders induce astrocyte damage, affecting CNS functionality. Glioprotective molecules can promote protection by improving glial functions and avoiding toxicity in different pathological conditions, including DM. Therefore, this review discusses specific pathomechanisms associated with DM/glucose metabolism disorder-induced gliotoxicity, namely astrocyte metabolism, redox homeostasis/mitochondrial activity, inflammation, and glial signaling pathways. Studies investigating natural products as potential glioprotective strategies against these deleterious effects of DM/glucose metabolism disorders are also reviewed herein. These products include carotenoids, catechins, isoflavones, lipoic acid, polysaccharides, resveratrol, and sulforaphane.

The Role of Astaxanthin on Chronic Diseases

Natural astaxanthin exists widely in algae, fungi, shrimp and crab, and, as a strong antioxidant, has potential effects on cardiovascular diseases, cancer, liver diseases and other physical health diseases. The treatment of many diseases involves the body’s signal transduction to regulate the body’s antioxidant defense system and inflammation. Astaxanthin is usually used as a dietary supplement, which plays an antioxidant and anti-inflammatory role in the organism. This article reviews the structure, source of astaxanthin and how it plays an anti-inflammatory and anti-oxidant role in organisms, especially in treating diabetes.

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

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

Unlocking the Health Potential of Microalgae as Sustainable Sources of Bioactive Compounds

Microalgae are known to produce a plethora of compounds derived from the primary and secondary metabolism. Different studies have shown that these compounds may have allelopathic, antimicrobial, and antipredator activities. In addition, in vitro and in vivo screenings have shown that several compounds have interesting bioactivities (such as antioxidant, anti-inflammatory, anticancer, and antimicrobial) for the possible prevention and treatment of human pathologies. Additionally, the enzymatic pathways responsible for the synthesis of these compounds, and the targets and mechanisms of their action have also been investigated for a few species. However, further research is necessary for their full exploitation and possible pharmaceutical and other industrial applications. Here, we review the current knowledge on the chemical characteristics, biological activities, mechanism of action, and the enzymes involved in the synthesis of microalgal metabolites with potential benefits for human health.

The Effect of Astaxanthin and Metformin on Oxidative Stress in Granulosa Cells of BALB C Mouse Model of Polycystic Ovary Syndrome

Reactive oxygen species (ROS), involved in the pathogenesis of the polycystic ovary syndrome (PCOS), play a key role in the onset of apoptosis in follicles and granulosa cells (GCs). We aimed to investigate the antioxidant effects of AST and metformin separately and in combination on GCs using a PCOS mouse model. Forty-eight prepubertal female BALB C mice aged 25-30 days and weighing 12-14 g were studied. The PCOS model was created by subcutaneous injection of the dehydroepiandrosterone (DHEA) hormone in 8 mice of BALB C for 20 consecutive days. Apoptosis and the amount of ROS were evaluated in GCs of the ovaries via flow cytometry. The activity of AKT protein was measured by western blot, and the viability of GCs was investigated using spectrophotometry. Ovarian tissue sections were prepared, stained with H&E, and the morphology of the sections was examined. Statistical analysis was performed by SPSS v22.0 software using one-way ANOVA. We found that AST administration leads to a significant reduction in oxidative stress (P<0.01) and consequently a significant decrease in the rate of apoptosis (P<0.01). While the expression of AKT in the AST group revealed a significant increase (P<0.05), it decreased in the metformin group. However, it was still significantly higher than the control and PCOS groups. Ovulation was confirmed in both metformin and AST groups. Further studies are warranted to prove the efficacy of AST and to introduce it as a complementary therapeutic agent in PCOS.

Therapeutic Potential of Astaxanthin in Diabetic Kidney Disease

Astaxanthin is a carotenoid that has potent protective effects on diabetic kidney disease (DKD) in diabetic mice models. DNA microarray study clearly demonstrated the involvement of mitochondrial oxidative phosphorylation pathway in the renal glomerular cells of diabetic mice and also showed that the expression of upregulated genes associated with this pathway was decreased by the treatment with astaxanthin. Proteomic analysis confirmed that the increases of 4-hydroxy-2-nonenal (HNE)- and N^ε-(hexanonyl)lysine (HEL)-modified proteins were inhibited by the treatment with astaxanthin. These results demonstrated that astaxanthin exerts a protective effect against hyperglycemia-induced DKD by attenuating mitochondrial oxidative stress and subsequent cellular dysfunction.

Marine Natural Products: Promising Candidates in the Modulation of Gut-Brain Axis towards Neuroprotection

In recent decades, several neuroprotective agents have been provided in combating neuronal dysfunctions; however, no effective treatment has been found towards the complete eradication of neurodegenerative diseases. From the pathophysiological point of view, growing studies are indicating a bidirectional relationship between gut and brain termed gut-brain axis in the context of health/disease. Revealing the gut-brain axis has survived new hopes in the prevention, management, and treatment of neurodegenerative diseases. Accordingly, introducing novel alternative therapies in regulating the gut-brain axis seems to be an emerging concept to pave the road in fighting neurodegenerative diseases. Growing studies have developed marine-derived natural products as hopeful candidates in a simultaneous targeting of gut-brain dysregulated mediators towards neuroprotection. Of marine natural products, carotenoids (e.g., fucoxanthin, and astaxanthin), phytosterols (e.g., fucosterol), polysaccharides (e.g., fucoidan, chitosan, alginate, and laminarin), macrolactins (e.g., macrolactin A), diterpenes (e.g., lobocrasol, excavatolide B, and crassumol E) and sesquiterpenes (e.g., zonarol) have shown to be promising candidates in modulating gut-brain axis. The aforementioned marine natural products are potential regulators of inflammatory, apoptotic, and oxidative stress mediators towards a bidirectional regulation of the gut-brain axis. The present study aims at describing the gut-brain axis, the importance of gut microbiota in neurological diseases, as well as the modulatory role of marine natural products towards neuroprotection.

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.

Inflammation/bioenergetics-associated neurodegenerative pathologies and concomitant diseases: a role of mitochondria targeted catalase and xanthophylls

Various inflammatory stimuli are able to modify or even "re-program" the mitochondrial metabolism that results in generation of reactive oxygen species. In noncommunicable chronic diseases such as atherosclerosis and other cardiovascular pathologies, type 2 diabetes and metabolic syndrome, these modifications become systemic and are characterized by chronic inflammation and, in particular, "neuroinflammation" in the central nervous system. The processes associated with chronic inflammation are frequently grouped into "vicious circles" which are able to stimulate each other constantly amplifying the pathological events. These circles are evidently observed in Alzheimer's disease, atherosclerosis, type 2 diabetes, metabolic syndrome and, possibly, other associated pathologies. Furthermore, chronic inflammation in peripheral tissues is frequently concomitant to Alzheimer's disease. This is supposedly associated with some common genetic polymorphisms, for example, Apolipoprotein-E ε4 allele carriers with Alzheimer's disease can also develop atherosclerosis. Notably, in the transgenic mice expressing the recombinant mitochondria targeted catalase, that removes hydrogen peroxide from mitochondria, demonstrates the significant pathology amelioration and health improvements. In addition, the beneficial effects of some natural products from the xanthophyll family, astaxanthin and fucoxanthin, which are able to target the reactive oxygen species at cellular or mitochondrial membranes, have been demonstrated in both animal and human studies. We propose that the normalization of mitochondrial functions could play a key role in the treatment of neurodegenerative disorders and other noncommunicable diseases associated with chronic inflammation in ageing. Furthermore, some prospective drugs based on mitochondria targeted catalase or xanthophylls could be used as an effective treatment of these pathologies, especially at early stages of their development.

Evaluation of microbiological, chemical, and sensory properties of cooked probiotic sausages containing different concentrations of astaxanthin, thymol, and nitrite

In this study, the effects of different concentrations of thymol and astaxanthin on control of Clostridium perfringenes and also microbial, chemical, and organoleptic properties of common and probiotic beef cooked sausages containing two levels of nitrite during storage at refrigerated condition during 45 days were evaluated. Based on findings, control group had significantly higher total volatile base nitrogen (TVB-N) than nitrite-, thymol-, and astaxanthin-treated samples. At the end of the storage time in control, thiobarbituric acid reactive substances (TBARS) value reached 1.96 mg/kg, while the values for treated samples remained lower than 1.63 mg/kg. Final count of lactic acid bacteria decreased approximately 1.67-3.79 log CFU/g in treated samples compared with the control group (p < .05). A reduction between 1.46 and 2.46 log CFU/g in C. perfringenes count was recorded for the treated samples in comparison with control group after 45 days of storage.

Astaxanthin alleviates gestational diabetes mellitus in mice through suppression of oxidative stress

Gestational diabetes mellitus (GDM) affects 7% of pregnant women worldwide, which increases the risk of diabetes and cardiovascular disease for both the mother and the fetus. Natural compound Astaxanthin has been reported to have benefits in obesity and diabetes. A pregnant C57BL/KsJ db/+ mouse was used as a genetic GDM model to investigate the effect of Astaxanthin on GDM symptoms and reproductive outcomes. Blood glucose, plasma insulin, glucose intolerance, insulin sensitivity, biochemical indexes of plasma, and the liver were measured; Nrf2 and HO-1 protein levels were detected by Western blotting. Astaxanthin significantly alleviated the glucose intolerance and β cell insufficiency, inhibited in vivo oxidative stress, enhanced the activity of antioxidant enzymes, and improved reproductive outcomes. Mechanistically, the effect of Astaxanthin was mediated by restoring the Nrf2/HO-1 antioxidant pathway in the liver of GDM mice. Our findings supported that Astaxanthin was a potential therapeutic reagent for not only diabetes but also GDM symptomology.

Network Pharmacology Combined with Transcriptional Analysis to Unveil the Biological Basis of Astaxanthin in Reducing the Oxidative Stress Induced by Diabetes Mellitus

PURPOSE

Astaxanthin (Ast) has been reported to reduce oxidative stress induced by diabetes mellitus (DM). The aim of this research was to give a systematic overview of the biological basis for this process.

METHODS

Ast-targeted proteins were collected from the BATMAN database, Comparative Toxicogenomics Database, and STITCH database. Putative DM-related protein targets were collected from the GeneCards database. A DM-rat model was then built with streptozotocin (STZ) combined with a high-sugar, high-fat diet for 30 days. Total cholesterol (TC), triglycerides (TGs), and insulin levels were examined using whole tail-vein blood from overnight-fasted rats. SOD, GSH, and MDA activy was detected in liver tissue (p<0.05). In addition, we used RNA-sequencing analysis to detect gene-transcription level in liver tissue of rats and GO biological process analysis to show all the log2FC≥2 genes in the Ast-fed DM rats compared with the DM group using the STRING database. Ast-intersecting targets were collected with Venn analysis. Docking analysis between Ast and targeted proteins was down with the SwissDock server. Ast targets-pathway networks were built using Cytoscape 3.7.2 software.

RESULTS

A total of 120 Ast-targeted proteins and 13,784 DM-related targets were collected. Ast functioned in reducing TC, TG, and MDA levels, promoting SOD activity and GSH expression, and alleviating islet-cell injury in Ast-fed DM rats compared with DM control rats. Furthermore, genes involved in MAPK, TNF, AMPK, and FOXO signaling pathways were differently expressed in Ast-treated DM rats compared with DM rats. The differentially expressed genes were enriched in euchromatin, thyroid cancer, and metaphase-plate congression. Three Ast-intersecting targets - Col5A1, Nqo1, and Notch2 - were then identified. We found possible binding patterns of Ast with Nqo1 and Notch2, respectively. Ast targets-pathway networks were finally built to show a systematic overview of how Ast works in multiple pathways to reduce oxidative stress. Taken together, Ast is predicted to target Col5A1, Nqo1, and Notch2 to form a network of systemic pharmacological effects to: 1) promote insulin-releasing balance and relieve insulin resistance, 2) reduce testicular cell apoptosis, and 3) maintain normal size in marginal-zone B cells and inhibit autoimmune DM, all of which contribute to the balance of lipid metabolism and reduction of oxidative stress in DM patients.

CONCLUSION

Ast functions in reducing oxidative stress in DM rats by regulating a variety of targets to form a comprehensive antioxidative network.