Protective effects of astaxanthin on 6-hydroxydopamine-induced apoptosis in human neuroblastoma SH-SY5Y cells

The potential of Pavlovophyceae species as a source of valuable carotenoids and polyunsaturated fatty acids for human consumption

Microalgae are a group of microorganisms, mostly photoautotrophs with high CO2 fixation capacity, that have gained increased attention in the last decades due to their ability to produce a wide range of valuable metabolites, such as carotenoids and polyunsaturated fatty acids, for application in food/feed, pharmaceutical, and cosmeceutical industries. Their increasing relevance has highlighted the importance of identifying and culturing new bioactive-rich microalgae species, as well as of a thorough understanding of the growth conditions to optimize the biomass production and master the biochemical composition according to the desired application. Thus, this review intends to describe the main cell processes behind the production of carotenoids and polyunsaturated fatty acids, in order to understand the possible main triggers responsible for the accumulation of those biocompounds. Their economic value and the biological relevance for human consumption are also summarized. In addition, an extensive review of the impact of culture conditions on microalgae growth performance and their biochemical composition is presented, focusing mainly on the studies involving Pavlovophyceae species. A complementary description of the biochemical composition of these microalgae is also presented, highlighting their potential applications as a promising bioresource of compounds for large-scale production and human and animal consumption.

A marine-derived antioxidant astaxanthin as a potential neuroprotective and neurotherapeutic agent: A review of its efficacy on neurodegenerative conditions

Astaxanthin is a potent lipid-soluble carotenoid produced by several different freshwater and marine microorganisms, including microalgae, bacteria, fungi, and yeast. The proven therapeutic effects of astaxanthin against different diseases have made this carotenoid popular in the nutraceutical market and among consumers. Recently, astaxanthin is also receiving attention for its effects in the co-adjuvant treatment or prevention of neurological pathologies. In this systematic review, studies evaluating the efficacy of astaxanthin against different neurodegenerative diseases such as Alzheimer's disease, Parkinson's disease, multiple sclerosis, cerebrovascular diseases, and spinal cord injury are analyzed. Based on the current literature, astaxanthin shows potential biological activity in both in vitro and in vivo models. In addition, its preventive and therapeutic activities against the above-mentioned diseases have been emphasized in studies with different experimental designs. In contrast, none of the 59 studies reviewed reported any safety concerns or adverse health effects as a result of astaxanthin supplementation. The preventive or therapeutic role of astaxanthin may vary depending on the dosage and route of administration. Although there is a consensus in the literature regarding its effectiveness against the specified diseases, it is important to determine the safe intake levels of synthetic and natural forms and to determine the most effective forms for oral intake.

Quercetin alleviates 6-OHDA-caused apoptosis in SH-SY5Y cells

Aim

This study is primarily designed to investigate the potential neuroprotective effects of polyphenol against 6-OHDAcaused neurotoxicity on SH-SY5Y cells.

Materials and Methods

Cytotoxic effect of 6-OHDA and valuable role of quercetin, myricetin and kaempferol on SH-SY5Y cells were analyzed by MTT assay. Generation of 6-OHDA-stimulated reactive oxygen species (ROS) was measured using DCFDA fluorescence dye. Alteration of 6-OHDA-caused mitochondrial membrane potential and nuclear condensation was investigated with the help of rhodamine-123 and hoechest stain. Immunoblotting was performed to detect the expression level of 6-OHDA-caused alpha-synuclein (á-syn), Bcl-2 associated protein X (BAX), caspase 3, cleaved Poly ADP - ribose polymerase (PARP) and Bcell lymphoma 2 proteins (Bcl-2).

Result

Through MTT assay, quercetin was selected over myricetin and kaempferol to counter 6-OHDA-caused cell death. The research delves into unraveling the intricate mechanisms underlying 6-OHDA-induced neurotoxicity, encompassing alterations in cellular morphology, escalation of oxidative stress, perturbation in mitochondrial membrane potential, and nuclear condensation. Exposure to 6-OHDA is implicated in the upregulation of á-syn protein, contributing to the aggravation of neurotoxicity. Concurrently, 6-OHDA orchestrates the apoptotic pathway by upregulating the expression of proapoptotic proteins such as BAX, caspase 3, and PARP, while down regulating the expression of the Bcl-2, affirming its role in apoptosis induction. Quercetin demonstrated ability to attenuate the expression of á-syn in the presence of 6-OHDA-caused injury in SH-SY5Y cells.

Conclusion

Taken together, these findings collectively underscore the therapeutic potential of quercetin as a promising agent against neurotoxicity caused by 6-OHDA.

The protective effect of parthenolide in an in vitro model of Parkinson's disease through its regulation of nuclear factor-kappa B and oxidative stress

BACKGROUND

Parkinson's disease (PD) is a neurodegenerative disorder characterized by motor and non-motor symptoms, and is due to the degeneration of dopaminergic neurons. It is multifactorial, caused by genetic and environmental factors and currently has no definitive cure. We have investigated the protective effects of parthenolide (PTN), a compound with known anti-inflammatory and antioxidant properties, in an in vitro model of PD, that is induced by 6-OHDA, and that causes neurotoxicity in SH-SY5Y human neuroblastoma cells.

METHODS AND RESULTS

SH-SY5Y cells were pretreated with PTN to assess its protective effects in 6-OHDA-induced cellular damage. Cell viability was measured using Alamar blue. Apoptosis was evaluated using an Annexin V-FITC/PI kit. Reactive oxygen species (ROS) levels were quantified, and expression levels of apoptotic markers (Bax, Bcl-2, p53) and NF-κB were analyzed via Western blotting and Quantitative real-time- (qRT-) PCR. We found that 6-OHDA reduced cell viability, that was inhibited significantly by pre-treatment with PTN (p < 0.05). Flow cytometry revealed that PTN reduced apoptosis induced by 6-OHDA. PTN also reduced the ROS levels raised by 6-OHDA (p < 0.05). Moreover, PTN decreased the expression of Bax, p53, NF-κB, and p-NF-κB that were increased by treatment with 6-OHDA.

CONCLUSION

These findings indicate the potential beneficial effects of PTN in an in vitro model of PD via mitigating oxidative stress and inflammation, suggested PTN as a promising agent to be used for PD therapy, warranting further investigation in preclinical and clinical studies.

Natural Antioxidants: An Effective Strategy for the Treatment of Alzheimer's Disease at the Early Stage

The critical role of oxidative stress in Alzheimer's disease (AD) has been recognized by researchers recently, and natural antioxidants have been demonstrated to have anti-AD activity in animal models, such as Ginkgo biloba extract, soy isoflavones, lycopene, and so on. This paper summarized these natural antioxidants and points out that natural antioxidants always have multiple advantages which are help to deal with AD, such as clearing free radicals, regulating signal transduction, protecting mitochondrial function, and synaptic plasticity. Based on the available data, we have created a relatively complete pathway map of reactive oxygen species (ROS) and AD-related targets and concluded that oxidative stress caused by ROS is the core of AD pathogenesis. In the prospect, we introduced the concept of a combined therapeutic strategy, termed "Antioxidant-Promoting Synaptic Remodeling," highlighting the integration of antioxidant interventions with synaptic remodeling approaches as a novel avenue for therapeutic exploration.

Traditional uses, botany, phytochemistry, and pharmacology of Lonicerae japonicae flos and Lonicerae flos: A systematic comparative review

ETHNOPHARMACOLOGICAL RELEVANCE

Lonicerae japonicae flos (LJF) and Lonicerae flos (LF) belong to different genera of Caprifoliaceae with analogous appearances and functions. Historically, they have been used as herbal medicines to treat various diseases with confirmed wind-heat evacuation, heat-clearing, and detoxification effects. However, the Chinese Pharmacopoeia (2005 Edition) lists LJF and LF under different categories.

AIM OF THE STUDY

Few studies have systematically compared the similarities and dissimilarities of LJF and LF concerning their research achievements. This systematic review and comparison of the traditional use, identification, and phytochemical and pharmacological properties of LJF and LF provides valuable insights for their further application and clinical safety.

MATERIALS AND METHODS

Related document information was collected from databases that included Web of Science, X-MOL, Science Direct, PubMed, and the China National Knowledge Infrastructure.

RESULTS

The chemical constituents and pharmacological effects of LJF and LF were similar. A total of 337 and 242 chemical constituents were isolated and identified in LJF and LF, respectively. These included volatile oils, cyclic ether terpenes, flavonoids, phenolic acids, triterpenoids, and their saponins. Additionally, LJF plants contain more iridoids and flavonoids than LF plants. The latter have a variety of triterpenoid saponins and significantly higher chlorogenic acid content than LJF plants. Pharmacological studies have shown that LJF and LF have various anti-inflammatory, antiviral, antibacterial, anti-endotoxic, antioxidant, anti-tumor, anti-platelet, myocardial protective, and hepatoprotective effects.

CONCLUSIONS

This review was undertaken to explore whether LJF and LF should be listed separately in the Chinese Pharmacopoeia in terms of their disease prevention and treatment strategies. Although LJF and LF showed promising effects, their action mechanisms remains unclear. Specifically, their impact on gut microbiota, gastrointestinal tract, and blood parameters requires further investigation. These studies will provide the foundation for scientific utilization and clinical/non-clinical applications of LJF and LF, and the maximum benefits from their mutual use.

ErbB2pY -1248 as a predictive biomarker for Parkinson's disease based on research with RPPA technology and in vivo verification

AIMS

This study aims to reveal a promising biomarker for Parkinson's disease (PD) based on research with reverse phase protein array (RPPA) technology for the first time and in vivo verification, which gains time for early intervention in PD, thus increasing the effectiveness of treatment and reducing disease morbidity.

METHODS AND RESULTS

We employed RPPA technology which can assess both total and post-translationally modified proteins to identify biomarker candidates of PD in a cellular PD model. As a result, the phosphorylation (pY-1248) of the epidermal growth factor receptor (EGFR) ErbB2 is a promising biomarker candidate for PD. In addition, lapatinib, an ErbB2 tyrosine kinase inhibitor, was used to verify this PD biomarker candidate in vivo. We found that lapatinib-attenuated dopaminergic neuron loss and PD-like behavior in the zebrafish PD model. Accordingly, the expression of ErbB2pY-1248 significantly increased in the MPTP-induced mouse PD model. Our results suggest that ErbB2pY-1248 is a predictive biomarker for PD.

CONCLUSIONS

In this study, we found that ErbB2pY-1248 is a predictive biomarker of PD by using RPPA technology and in vivo verification. It offers a new perspective on PD diagnosing and treatment, which will be essential in identifying individuals at risk of PD. In addition, this study provides new ideas for digging into biomarkers of other neurodegenerative diseases.

Dipeptide mimetic of BDNF ameliorates motor dysfunction and striatal apoptosis in 6-OHDA-induced Parkinson's rat model: Considering Akt and MAPKs signaling

Parkinson's disease (PD) is a progressive and debilitating neurodegenerative disorder associated with motor and non-motor complaints. Dysregulation of neurotrophic factors and related signaling cascades have been reported to be common events in PD which is accompanied by dopaminergic (DA) neuron demise. However, the restoration of neurotrophic factors has several limitations. Bis-(N-monosuccinyl-L-methionyl-L-serine) heptamethylenediamide (BHME) is a dipeptide mimetic of brain-derived neurotrophic factor (BDNF) with reported anti-oxidant and neuroprotective effects in several experimental models. The current study has investigated the effect of BHME on 6-hydroxydopamine (6-OHDA)-caused motor anomalies in Wistar rats. In this regard, rats were treated daily with BHME (0.1 or 1 mg/kg) 1 h after 6-OHDA-caused damage until the twelfth day. Afterwards, motor behavior and DA neuron survival were evaluated via behavioral tests and immunohistochemistry (IHC) staining, respectively. Moreover, the activity of Akt, mitogen-activated protein kinases (MAPKs) family, and Bax/Bcl-2 ratio were evaluated by Western blotting. Our results indicated that BHME prevents motor dysfunction and DA cell death following 6-OHDA injection, and this improvement was in parallel with an enhancement in Akt activity, decrement of P38 phosphorylation, along with a reduction in Bax/Bcl-2 ratio. In conclusion, our findings indicated that BHME, as a mimetic of BDNF, can be considered for further research and is a promising therapeutic agent for PD therapy.

Combined Donepezil with Astaxanthin via Nanostructured Lipid Carriers Effective Delivery to Brain for Alzheimer's Disease in Rat Model

Introduction

Donepezil (DPL), a specific acetylcholinesterase inhibitor, is used as a first-line treatment to improve cognitive deficits in Alzheimer's disease (AD) and it might have a disease modifying effect. Astaxanthin (AST) is a natural potent antioxidant with neuroprotective, anti-amyloidogenic, anti-apoptotic, and anti-inflammatory effects. This study aimed to prepare nanostructured lipid carriers (NLCs) co-loaded with donepezil and astaxanthin (DPL/AST-NLCs) and evaluate their in vivo efficacy in an AD-like rat model 30 days after daily intranasal administration.

Methods

DPL/AST-NLCs were prepared using a hot high-shear homogenization technique, in vitro examined for their physicochemical parameters and in vivo evaluated. AD induction in rats was performed by aluminum chloride. The cortex and hippocampus were isolated from the brain of rats for biochemical testing and histopathological examination.

Results

DPL/AST-NLCs showed z-average diameter 149.9 ± 3.21 nm, polydispersity index 0.224 ± 0.017, zeta potential -33.7 ± 4.71 mV, entrapment efficiency 81.25 ±1.98% (donepezil) and 93.85 ±1.75% (astaxanthin), in vitro sustained release of both donepezil and astaxanthin for 24 h, spherical morphology by transmission electron microscopy, and they were stable at 4-8 ± 2°C for six months. Differential scanning calorimetry revealed that donepezil and astaxanthin were molecularly dispersed in the NLC matrix in an amorphous state. The DPL/AST-NLC-treated rats showed significantly lower levels of nuclear factor-kappa B, malondialdehyde, β-site amyloid precursor protein cleaving enzyme-1, caspase-3, amyloid beta (Aβ1‑42), and acetylcholinesterase, and significantly higher levels of glutathione and acetylcholine in the cortex and hippocampus than the AD-like untreated rats and that treated with donepezil-NLCs. DPL/AST-NLCs showed significantly higher anti-amyloidogenic, antioxidant, anti-acetylcholinesterase, anti-inflammatory, and anti-apoptotic effects, resulting in significant improvement in the cortical and hippocampal histopathology.

Conclusion

Nose-to-brain delivery of DPL/AST-NLCs is a promising strategy for the management of AD.

Enhancing the neuroprotective effect of squid outer skin astaxanthin against rotenone-induced neurotoxicity in in-vitro model for Parkinson's disease

Rotenone is a widely used organic pesticide that induces neurotoxicity via inhibition of mitochondrial complex I and oxidative stress actions for the most of dopaminergic neurons as that occurring in Parkinsonism disease (PD). Astaxanthin (ASX) is a natural pigment (carotenoids) and a potent therapeutic compound due to its antioxidant and anti-inflammatory properties. The commercially important cephalopod Doryteuthis singhalensis is widely distributed in tropical and subtropical waters in World Ocean. D. singhalensis is an important source of astaxanthin that contains valuable biological active compounds with many valuable pharmacological effects. The present study evaluated the effect of astaxanthin in preventing rotenone-induced toxicity of SK-N-SH human neuroblastoma cells in an in vitro model of experimental Parkinsonism. The results revealed the strongly significant antioxidant capability of extracted squid astaxanthin in 1,1- diphenyl- 2- picrylhydrazyl (DPPH) radical scavenging activity. In addition, astaxanthin treatment based on dose dependent manner significantly attenuated rotenone induced cytotoxicity, mitochondrial dysfunction and oxidative stress in SKN- SH cells. It is concluded that the marine squid derived astaxanthin could be used as a potential neuroprotector against rotenone induced toxicity due to its antioxidant, and anti-apoptotic properties. Consequently, it could be a supportive remedy for neurodegenerative diseases like Parkinson's disease.

Marine-Derived Compounds Applied in Cardiovascular Diseases: Submerged Medicinal Industry

Cardiovascular diseases (CVDs) are among the most impactful illnesses globally. Currently, the available therapeutic option has several side effects, including hypotension, bradycardia, arrhythmia, and alteration in different ion concentrations. Recently, bioactive compounds from natural sources, including plants, microorganisms, and marine creatures, have gained a lot of interest. Marine sources serve as reservoirs for new bioactive metabolites with various pharmacological activities. The marine-derived compound such as omega-3 acid ethyl esters, xyloketal B, asperlin, and saringosterol showed promising results in several CVDs. The present review focuses on marine-derived compounds' cardioprotective potential for hypertension, ischemic heart disease, myocardial infarction, and atherosclerosis. In addition to therapeutic alternatives, the current use of marine-derived components, the future trajectory, and restrictions are also reviewed.

Potential candidates from marine and terrestrial resources targeting mitochondrial inhibition: Insights from the molecular approach

Mitochondria are the target sites for multiple disease manifestations, for which it is appealing to researchers' attention for advanced pharmacological interventions. Mitochondrial inhibitors from natural sources are of therapeutic interest due to their promising benefits on physiological complications. Mitochondrial complexes I, II, III, IV, and V are the most common sites for the induction of inhibition by drug candidates, henceforth alleviating the manifestations, prevalence, as well as severity of diseases. Though there are few therapeutic options currently available on the market. However, it is crucial to develop new candidates from natural resources, as mitochondria-targeting abnormalities are rising to a greater extent. Marine and terrestrial sources possess plenty of bioactive compounds that are appeared to be effective in this regard. Ample research investigations have been performed to appraise the potentiality of these compounds in terms of mitochondrial disorders. So, this review outlines the role of terrestrial and marine-derived compounds in mitochondrial inhibition as well as their clinical status too. Additionally, mitochondrial regulation and, therefore, the significance of mitochondrial inhibition by terrestrial and marine-derived compounds in drug discovery are also discussed.

Natural Astaxanthin Is a Green Antioxidant Able to Counteract Lipid Peroxidation and Ferroptotic Cell Death

Astaxanthin is a red orange xanthophyll carotenoid produced mainly by microalgae but which can also be chemically synthesized. As demonstrated by several studies, this lipophilic molecule is endowed with potent antioxidant properties and is able to modulate biological functions. Unlike synthetic astaxanthin, natural astaxanthin (NAst) is considered safe for human nutrition, and its production is considered eco-friendly. The antioxidant activity of astaxanthin depends on its bioavailability, which, in turn, is related to its hydrophobicity. In this study, we analyzed the water-solubility of NAst and assessed its protective effect against oxidative stress by means of different approaches using a neuroblastoma cell model. Moreover, due to its highly lipophilic nature, astaxanthin is particularly protective against lipid peroxidation; therefore, the role of NAst in counteracting ferroptosis was investigated. This recently discovered process of programmed cell death is indeed characterized by iron-dependent lipid peroxidation and seems to be linked to the onset and development of oxidative-stress-related diseases. The promising results of this study, together with the "green sources" from which astaxanthin could derive, suggest a potential role for NAst in the prevention and co-treatment of chronic degenerative diseases by means of a sustainable approach.

Citronellol Prevents 6-OHDA-Induced Oxidative Stress, Mitochondrial Dysfunction, and Apoptosis in Parkinson Disease Model of SH-SY5Y Cells via Modulating ROS-NO, MAPK/ERK, and PI3K/Akt Signaling Pathways

Parkinson disease is a neurodegenerative disorder distinguished by dopaminergic shortage in the striatum and the accumulation of α-synuclein neuronal aggregates in the brains of patients. Since, there is no accurate treatment available for Parkinson disease, researches are designed to alleviate the pathognomonic symptoms such as neuroinflammation, oxidative stress, mitochondrial dysfunction, and apoptosis. Accordingly, a number of compounds have been reported to inhibit these pathognomonic symptoms. In this study, we have assessed the neuroprotective potential of citronellol against 6-OHDA-induced neurotoxicity in SH-SY5Y cells. The results found that citronellol treatment effectively hindered the cell death caused by 6-OHDA and thereby maintaining the cell viability in SH-SY5Y cells at 50 µg/mL concentration. As expected, the citronellol treatment significantly reduced the 6-OHDA-induced secretion of inflammatory factors (IL-1β, IL-6, and TNF-α), which was obtained through ELISA technique. Similarly, citronellol hindered the 6-OHDA-induced oxidative stress by lowering the intracellular ROS and NO level and MDA leakage along with increased expression of SOD level in SH-SY5Y cells. The JC-1 staining showed that 6-OHDA increased the number of green fluorescent dots with ruptured mitochondrial membrane potential, while citronellol increased the amount of red fluorescent, showing the rescue potential against the 6-OHDA-induced mitochondrial dysfunction. Furthermore, citronellol hampered the 6-OHDA-induced apoptosis via the suppression of Bcl-2/Bax pathway. The western blotting results hypothesized that citronellol rescued SH-SY5Y cells from 6-OHDA-induced neurotoxicity via modulating ROS-NO, MAPK/ERK, and PI3K/Akt signaling pathways. However, further clinical trials are required to verify the anti-Parkinson efficacy.

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.

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.

Algae as an emerging source of bioactive pigments

Algae have been identified as natural producer of bioactive commercial pigments. To perform photosynthesis, algae use pigments to harvest sunlight energy. The pigments found in algae are categorized in chlorophylls, phycobilins, and carotenoids. Popular carotenoids include astaxanthin, lutein,fucoxanthin, canthaxanthin, zeaxanthin, β-cryptoxanthin and finds application as antioxidant, anti-inflammatory, immunoprophylactic, antitumor activities among others. Due to double-bonds in their structure, they exhibit broad health applications while protecting other molecules from oxidative stress induced by active radicals using various mechanisms. These carotenoids are synthesized by certain species as major products however they also present as byproducts in several species based on the pathway and genetic capability. Haematococcus pluvialis and Chlorella zofingiensis are ideal strains for commercial astaxanthin production. This review provides recent updates on microalgal pigment production, extraction, and purification processes to standardize and analyze for commercial production. Also, discussed the factors affecting its production, application, market potential, bottlenecks, and future prospects.

A review: traditional herbs and remedies impacting pathogenesis of Parkinson's disease

Parkinson's disease (PD) is characterized by progressive degeneration of dopaminergic neurons, leading to misbalance and loss of coordination. Current therapies are claimed only for symptomatic relief, on long-term use, which causes alteration in basal ganglia, and give rise to various adverse effects like dyskinesia and extra pyramidal side effects, which is reversed and proved to be attenuated with the help of various herbal approaches. Therefore, in order to attenuate the dopaminergic complications, focus of current research has been shifted from dopaminergic to non-dopaminergic strategies. Herbs and herbal remedies seems to be a better option to overcome the complications associated with current dopaminergic therapies. In recent years, various herbs and herbal remedies based on Ayurveda, traditional Chinese and Korean remedies, have become the target of various researches. These herbs and their bioactive compound are being extensively used to treat PD in India, China, Japan, and Korea. The major focus of this current review is to analyze preclinical studies with reference to various herbs, bioactive compounds, and traditional remedies for the management of Parkinson disorder, which will give an insight towards clinical trials.

An Overview of Autophagy in Helicobacter pylori Infection and Related Gastric Cancer

Helicobacter pylori (H. pylori) infection is considered a class I carcinogen in the pathogenesis of gastric cancer. In recent years, the interaction relationship between H. pylori infection and autophagy has attracted increasing attention. Most investigators believe that the pathogenesis of gastric cancer is closely related to the formation of an autophagosome-mediated downstream signaling pathway by H. pylori infection-induced cells. Autophagy is involved in H. pylori infection and affects the occurrence and development of gastric cancer. In this paper, the possible mechanism by which H. pylori infection affects autophagy and the progression of related gastric cancer signaling pathways are reviewed.

Nutraceuticals as Modulators of Autophagy: Relevance in Parkinson’s Disease

Dietary supplements and nutraceuticals have entered the mainstream. Especially in the media, they are strongly advertised as safe and even recommended for certain diseases. Although they may support conventional therapy, sometimes these substances can have unexpected side effects. This review is particularly focused on the modulation of autophagy by selected vitamins and nutraceuticals, and their relevance in the treatment of neurodegenerative diseases, especially Parkinson’s disease (PD). Autophagy is crucial in PD; thus, the induction of autophagy may alleviate the course of the disease by reducing the so-called Lewy bodies. Hence, we believe that those substances could be used in prevention and support of conventional therapy of neurodegenerative diseases. This review will shed some light on their ability to modulate the autophagy.

Therapeutic promise of carotenoids as antioxidants and anti-inflammatory agents in neurodegenerative disorders

Neurodegenerative disorders (NDs) including Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis, Huntington's disease, and multiple sclerosis have various disease-specific causal factors and pathological features. A very common characteristic of NDs is oxidative stress (OS), which takes place due to the elevated generation of reactive oxygen species during the progression of NDs. Furthermore, the pathological condition of NDs including an increased level of protein aggregates can further lead to chronic inflammation because of the microglial activation. Carotenoids (CTs) are naturally occurring pigments that play a significant role in averting brain disorders. More than 750 CTs are present in nature, and they are widely available in plants, microorganisms, and animals. CTs are accountable for the red, yellow, and orange pigments in several animals and plants, and these colors usually indicate various types of CTs. CTs exert various bioactive properties because of its characteristic structure, including anti-inflammatory and antioxidant properties. Due to the protective properties of CTs, levels of CTs in the human body have been markedly linked with the prevention and treatment of multiple diseases including NDs. In this review, we have summarized the relationship between OS, neuroinflammation, and NDs. In addition, we have also particularly focused on the antioxidants and anti-inflammatory properties of CTs in the management of NDs.

[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 Identification of Prohibitin in the Rat Heart Mitochondria in Heart Failure

Mitochondria are considered the main organelles in the cell. They play an important role in both normal and abnormal heart function. There is a supramolecular organization between the complexes of the respiratory chain (supercomplexes (SCs)), which are involved in mitochondrial respiration. Prohibitins (PHBs) participate in the regulation of oxidative phosphorylation (OXPHOS) activity and interact with some subunits of the OXPHOS complexes. In this study, we identified a protein whose level was decreased in the mitochondria of the heart in rats with heart failure. This protein was PHB. Isoproterenol (ISO) has been used as a compound to induce heart failure in rats. We observed that astaxanthin (AX) increased the content of PHB in rat heart mitochondria isolated from ISO-injected rats. Since it is known that PHB forms complexes with some mitochondrial proteins and proteins that are part of the complexes of the respiratory chain, the change in the levels of these proteins was investigated under our experimental conditions. We hypothesized that PHB may be a target for the protective action of AX.

Dietary agents in mitigating chemotherapy-related cognitive impairment (chemobrain or chemofog): first review addressing the benefits, gaps, challenges and ways forward

Chemobrain or chemofog is one of the important but less investigated side effects, where the cancer survivors treated with chemotherapy develop long-term cognitive impairments, affecting their quality of life. The biological mechanisms triggering the development of chemobrain are largely unknown. However, a literature study suggests the generation of free radicals, oxidative stress, inflammatory cytokines, epigenetic chromatin remodeling, decreased neurogenesis, secretion of brain-derived neurotropic factor (BDNF), dendritic branching, and neurotransmitter release to be the cumulative contributions to the ailment. Unfortunately, there is no means to prevent/mitigate the development and intensity of chemobrain. Given the lack of effective prevention strategies or treatments, preclinical studies have been underway to ascertain the usefulness of natural products in mitigating chemobrain in the recent past. Natural products used in diets have been shown to provide beneficial effects by inhibition of free radicals, oxidative stress, inflammatory processes, and/or concomitant upregulation of various cell survival proteins. For the first time, this review focuses on the published effects of astaxanthin, omega-3 fatty acids, ginsenoside, cotinine, resveratrol, polydatin, catechin, rutin, naringin, curcumin, dehydrozingerone, berberine, C-phycocyanin, the higher fungi Cordyceps militaris, thyme (Thymus vulgaris) and polyherbal formulation Mulmina™ in mitigating cognitive impairments in preclinical models of study, and also addresses their potential neuro-therapeutic mechanisms and applications in preventing/ameliorating chemobrain.

The neuroprotective potential of carotenoids in vitro and in vivo

BACKGROUND

Despite advances in research on neurodegenerative diseases, the pathogenesis and treatment response of neurodegenerative diseases remain unclear. Recent studies revealed a significant role of carotenoids to treat neurodegenerative diseases. The aim of this study was to systematically review the neuroprotective potential of carotenoids in vivo and in vitro and the molecular mechanisms and pathological factors contributing to major neurodegenerative diseases (Alzheimer's disease, Huntington's disease, Parkinson's disease, amyotrophic lateral sclerosis, and stroke).

HYPOTHESIS

Carotenoids as therapeutic molecules to target neurodegenerative diseases.

RESULTS

Aggregation of toxic proteins, mitochondrial dysfunction, oxidative stress, the excitotoxic pathway, and neuroinflammation were the major pathological factors contributing to the progression of neurodegenerative diseases. Furthermore, in vitro and in vivo studies supported the beneficiary role of carotenoids, namely lycopene, β-carotene, crocin, crocetin, lutein, fucoxanthin and astaxanthin in alleviating disease progression. These carotenoids provide neuroprotection by inhibition of neuro-inflammation, microglial activation, excitotoxic pathway, modulation of autophagy, attenuation of oxidative damage and activation of defensive antioxidant enzymes. Additionally, studies conducted on humans also demonstrated that dietary intake of carotenoids lowers the risk of neurodegenerative diseases.

CONCLUSION

Carotenoids may be used as drugs to prevent and treat neurodegenerative diseases. Although, the in vitro and in vivo results are encouraging, further well conducted clinical studies on humans are required to conclude about the full potential of neurodegenerative diseases.

Neuroprotective effect of α-pinene self-emulsifying nanoformulation against 6-OHDA induced neurotoxicity on human SH-SY5Y cells and its in vivo validation for anti-Parkinson's effect

Oxidative stress (OS) is involved in the multifaceted pathogenic paradigm of neurodegenerative diseases like Parkinson's disease (PD). Monoterpenes like α-pinene (ALP) is considered to be a therapeutically potent antioxidant agent able to attenuate and scavenge various reactive oxygen species and reactive nitrogen species. The present study aimed to evaluate the in vitro and in vivo neuroprotective effect of α-pinene self-emulsifying nanoformulation (ALP-SENF) for PD. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay was done to evaluate the neurotoxic dose of the ALP-SENF; however, the neuroprotective effect was assessed by 6-hydroxydopamine (6-OHDA) induced neurotoxicity model on SH-SY5Y taking NAC (N-acetyl-l-cysteine) as standard. The in vivo anti-Parkinson's activity of the ALP-SENF was compared with that of the plain ALP suspension by using reserpine antagonism and haloperidol-induced Parkinsonism model in rats. Various behavioral tests and biochemical antioxidant enzymes were estimated. The in vitro results revealed that treatment with ALP-SENF at a concentration of 100 and 200 µM was found to show significant neuronal SH-SY5Y cell viability against 50 µM 6-OHDA. ALP-SENF treated animals have seen significant neurobehavioral improvement. Furthermore, the levels of antioxidative enzymes in biochemical test reveals a marked enhancement in the expression of antioxidant enzymes that significantly attenuated the OS induced neurodegeneration. Due to the mechanisms of their antioxidant action, it was probably due to the scavenging of free radicals and the expression of antioxidant enzymes. It also improved neurobehavioral changes induced by reserpine and haloperidol.

Central Nervous System Migration of Astaxanthin and Adonixanthin Following Their Oral Administration in Cynomolgus Monkeys

Astaxanthin, which has been shown to have significant antioxidant activity, is rapidly spreading as a health functioning ingredient in the health food and cosmetics sectors worldwide. It is well known that astaxanthin acts on the brain; however, there is little evidence of brain translocation due to the difficulty in identifying astaxanthin in tissues. Therefore, in this study, we investigated the concentrations of astaxanthin and adonixanthin, the latter being a biosynthetic intermediate from β-carotene to astaxanthin, in the brain after oral administration in primates. Cynomolgus monkeys were orally administered astaxanthin or adonixanthin at a dose of 50 mg/kg for 10 d, through a disposable catheter inserted into the stomach via the nasal passage. Following euthanization, the monkeys' brains and various other organs were collected. The carotenoid content in serum and individual organs was analyzed by high-performance liquid chromatography. Adonixanthin was found to accumulate at a higher concentration than astaxanthin in monkey brain tissues. Also, both astaxanthin and adonixanthin were found to be distributed in the heart, spleen, liver, and kidneys. These findings indicate that astaxanthin and adonixanthin can enter the central nervous system of primates following their oral administration. This provides important evidence for the activity of astaxanthin and adonixanthin on the central nervous system.

Astaxanthin Protects Human Granulosa Cells against Oxidative Stress through Activation of NRF2/ARE Pathway and Its Downstream Phase II Enzymes

Objective

Astaxanthin (AST) has been introduced as a radical scavenger and an anti-apoptotic factor that acts via regulating the nuclear factor-E2-related factor 2 (NRF2) and related factors. Here, we intended to examine the effect of AST on granulosa cells (GCs) against oxidative stress by examining NRF2 and downstream phase II antioxidant enzymes.

Materials and Methods

In this experimental study, we used cultured human primary GCs for the study. First, we performed the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) test to evaluate cells viability after treatment with hydrogen peroxide (H2O2) and AST. The apoptosis rate and ROS levels were measured by flow cytometry. To determine NRF2 and phase II enzymes expression, we performed real-time polymerase chain reaction (PCR). Finally, we used western blot to measure the protein levels of NRF2 and Kelch-like ECsH-associated protein 1 (KEAP1). Enzyme activity analysis was also performed to detect NRF2 activity.

Results

This study showed that AST suppressed ROS generation (P<0.01) and cell death (P<0.05) in GCs induced by oxidative stress. AST also elevated gene and protein expression and nuclear localization of NRF2 and had an inhibitory effect on the protein levels of KEAP1 (P<0.05). Furthermore, when we used trigonelline (Trig) as a known inhibitor of NRF2, it attenuated the protective effects of AST by decreasing NRF2 activity and gene expression of phase II enzymes (P<0.05).

Conclusion

Our results presented the protective role of AST against oxidative stress in GCs which was mediated through up-regulating the phase II enzymes as a result of NRF2 activation. Our study may help in improving in vitro fertilization (IVF) outcomes and treatment of infertility.

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

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

On the therapeutic targets and pharmacological treatments for pain relief following spinal cord injury: A mechanistic review

Spinal cord injury (SCI) is globally considered as one of the most debilitating disorders, which interferes with daily activities and life of the affected patients. Despite many developments in related recognizing and treating procedures, post-SCI neuropathic pain (NP) is still a clinical challenge for clinicians with no distinct treatments. Accordingly, a comprehensive search was conducted in PubMed, Medline, Scopus, Web of Science, and national database (SID and Irandoc). The relevant articles regarding signaling pathways, therapeutic targets and pharmacotherapy of post-SCI pain were also reviewed. Data were collected with no time limitation until November 2020. The present study provides the findings on molecular mechanisms and therapeutic targets, as well as developing the critical signaling pathways to introduce novel neuroprotective treatments of post-SCI pain. From the pathophysiological mechanistic point of view, post-SCI inflammation activates the innate immune system, in which the immune cells elicit secondary injuries. So, targeting the critical signaling pathways for pain management in the SCI population has significant importance in providing new treatments. Indeed, several receptors, ion channels, excitatory neurotransmitters, enzymes, and key signaling pathways could be used as therapeutic targets, with a pivotal role of n-methyl-D-aspartate, gamma-aminobutyric acid, and inflammatory mediators. The current review focuses on conventional therapies, as well as crucial signaling pathways and promising therapeutic targets for post-SCI pain to provide new insights into the clinical treatment of post-SCI pain. The need to develop innovative delivery systems to treat SCI is also considered.

Hesperidin alleviates bupivacaine anesthesia-induced neurotoxicity in SH-SY5Y cells by regulating apoptosis and oxidative damage

Local anesthetic with bupivacaine (BV) administration may cause severe neurotoxicity and neurological complications in developing neurons. Any substances that can mitigate the toxic effects of BV are of great importance in surgical procedures and pain management. The present study attempted to investigate if hesperidin (HN) could inhibit or prevent BV-induced neurotoxicity in SH-SY5Y cells. Exposure of BV at 5 mM resulted in a significant decrease of cell viability and a remarkable increase of lactate dehydrogenase release via the induction of apoptosis and production of reactive oxygen species. Moreover, a loss of mitochondrial membrane potential, decreased Bcl-2 protein expression, as well as increased expression of cytoplasmic cytochrome c, Bax, and cleaved caspase-3 protein was also observed in BV-stimulated SH-SY5Y cells. In addition, BV stimulation impaired the balance of oxidation-reduction and inflammation system, as evidenced by the increased malondialdehyde content, decreased superoxide dismutase and catalase activity, and reduced level of reduced glutathione, interleukin-6 (IL-6), IL-1β, and tumor necrosis factor-α. However, these iatrogenic changes were all reversed by the HN (5, 10, and 20 μM) supplement for 48 h in a concentration-dependent manner. In conclusion, HN can protect SH-SY5Y cells against BV-stimulated neurotoxicity via the inhibition of apoptosis, oxidative stress, and inflammation response. The present findings suggested that HN may be an effective alternative agent to inhibit or prevent BV-induced neurotoxicity in human patients.

Molecular Mechanisms of Astaxanthin as a Potential Neurotherapeutic Agent

Neurological disorders are diseases of the central and peripheral nervous system that affect millions of people, and the numbers are rising gradually. In the pathogenesis of neurodegenerative diseases, the roles of many signaling pathways were elucidated; however, the exact pathophysiology of neurological disorders and possible effective therapeutics have not yet been precisely identified. This necessitates developing multi-target treatments, which would simultaneously modulate neuroinflammation, apoptosis, and oxidative stress. The present review aims to explore the potential therapeutic use of astaxanthin (ASX) in neurological and neuroinflammatory diseases. ASX, a member of the xanthophyll group, was found to be a promising therapeutic anti-inflammatory agent for many neurological disorders, including cerebral ischemia, Parkinson's disease, Alzheimer's disease, autism, and neuropathic pain. An effective drug delivery system of ASX should be developed and further tested by appropriate clinical trials.

Anti-androgenic effect of astaxanthin in LNCaP cells is mediated through the aryl hydrocarbon-androgen receptors cross talk

The aim of this study was to investigate the anti-androgenic effects of astaxanthin (AST) on human prostatic cancer cell growth, and its impact on androgen receptor (AR) signaling using prostate cancer (PCa) cell line LNCaP. LNCaP cells were treated with AST alone and in combination with CH223191 and flutamide (Flu) in the presence and absence of testosterone. MTT assay, cellular prostate-specific antigen (PSA) and dihydrotestosterone (DHT) production, mRNA levels of CYP1A1, PSA, Kallikrein-Related Peptidase 2 (KLK2), Transmembrane Serine Protease 2 (TMPRSS2), and AR genes were measured as endpoints. The expression of CYP1A1, PSA, KLK2, TMPRSS2, and AR mRNA levels was decreased which results in reducing the production of PSA and DHT in the presence of testosterone. Our data clearly demonstrate that AST has a potential ability to suppress the human prostate LNCaP cells growth at high concentrations. AST was able to repress the testosterone-induced transcription of AR-target genes. PRACTICAL APPLICATIONS: Astaxanthin is a natural compound with the most potent antioxidant activity among other antioxidants. In the current study, ASX suppressed the LNCaP cells at high concentrations. Furthermore, AST inhibited testosterone-induced transcriptional activation of androgen-related genes. AST induced the expression of CYP1A1, which is able to metabolize the steroid hormones. It seems that AST can act as AhR exogenous ligand by induction of CYP1A1, which results in testosterone metabolism and consequent suppression of AR genes. So that, AST could prevent the growth of testosterone-dependent PCa cells, downregulate downstream genes in testosterone pathways, and enhance the metabolism of testosterone via AhR pathway. Collectively, AST could be considered as a potential candidate for the treatment of PCa.

Characterization, antioxidant, and cytotoxic effects of some Egyptian wild plant extracts

Background

Natural products from plants are very safe as compared to synthetic ones, so the aim of this study was to assess the in vitro antioxidant and antitumor activities of the ethanolic extracts of four Egyptian wild plant species (Varthemia candicans, Peganum harmala, Suaeda vermiculata, and Conyza dioscoridis), as well as polyphenols and flavonoid contents with gas chromatography–mass spectrometry (GC-MS). The antioxidant activity of the four plant extracts was assessed using 2,2-diphenyl-1-picrylhydrazyl (DPPH) to determine 50% inhibition of DPPH radical scavenging activity and reducing power by phosphomolybdate assay. In addition, the chemical composition of the four sample extracts was investigated using GC-MS. The total phenolic and flavonoid levels were also determined. Then, the antitumor activity of the plant extracts against HepG2 cells was determined using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay.

Results

The results showed that Varthemia candicans extract was the highest one regarding both polyphenols and flavonoid contents. Moreover, the extract of Suaeda vermiculata exhibited the lowest half maximum inhibitory concentration (IC50) against DPPH, thus indicating its highest effectiveness. All studied plant extracts decreased the viability of HepG2 cells, in a dose- and time-dependent manner, and the lowest IC50 was for Suaeda vermiculata.

Conclusion

The investigated plant extracts showed potent antioxidant and antitumor activities in vitro due to their phytochemical contents.

Benefits under the Sea: The Role of Marine Compounds in Neurodegenerative Disorders

Marine habitats offer a rich reservoir of new bioactive compounds with great pharmaceutical potential; the variety of these molecules is unique, and its production is favored by the chemical and physical conditions of the sea. It is known that marine organisms can synthesize bioactive molecules to survive from atypical environmental conditions, such as oxidative stress, photodynamic damage, and extreme temperature. Recent evidence proposed a beneficial role of these compounds for human health. In particular, xanthines, bryostatin, and 11-dehydrosinulariolide displayed encouraging neuroprotective effects in neurodegenerative disorders. This review will focus on the most promising marine drugs' neuroprotective potential for neurodegenerative disorders, such as Parkinson's and Alzheimer's diseases. We will describe these marine compounds' potential as adjuvant therapies for neurodegenerative diseases, based on their antioxidant, anti-inflammatory, and anti-apoptotic properties.

Cognitive Effects of Astaxanthin Pretreatment on Recovery From Traumatic Brain Injury

Traumatic brain injury (TBI), caused by mechanical impact to the brain, is a leading cause of death and disability among young adults, with slow and often incomplete recovery. Preemptive treatment strategies may increase the injury resilience of high-risk populations such as soldiers and athletes. In this work, the xanthophyll carotenoid Astaxanthin was examined as a potential nutritional preconditioning method in mice (sabra strain) to increase their resilience prior to TBI in a closed head injury (CHI) model. The effect of Astaxanthin pretreatment on heat shock protein (HSP) dynamics and functional outcome after CHI was explored by gavage or free eating (in pellet form) for 2 weeks before CHI. Assessment of neuromotor function by the neurological severity score (NSS) revealed significant improvement in the Astaxanthin gavage-treated group (100 mg/kg, ATX) during recovery compared to the gavage-treated olive oil group (OIL), beginning at 24 h post-CHI and lasting throughout 28 days (p < 0.007). Astaxanthin pretreatment in pellet form produced a smaller improvement in NSS vs. posttreatment at 7 days post-CHI (p < 0.05). Cognitive and behavioral evaluation using the novel object recognition test (ORT) and the Y Maze test revealed an advantage for Astaxanthin administration via free eating vs. standard chow during recovery post-CHI (ORT at 3 days, p < 0.035; improvement in Y Maze score from 2 to 29 days, p < 0.02). HSP profile and anxiety (open field test) were not significantly affected by Astaxanthin. In conclusion, astaxanthin pretreatment may contribute to improved recovery post-TBI in mice and is influenced by the form of administration.

Astaxanthin Improved the Cognitive Deficits in APP/PS1 Transgenic Mice Via Selective Activation of mTOR

Astaxanthin (Ast) is an effective neuroprotective and antioxidant compound used to treat Alzheimer's disease (AD); however, the underlying in vivo molecular mechanisms remain unknown. In this study, we report that Ast can activate the mammalian target of rapamycin (mTOR) pathway in the 8-month-old APP/PS1 transgenic mouse model of AD. Our results suggest that Ast could ameliorate the cognitive defects in APP/PS1 mice by activating the mTOR pathway. Moreover, mTOR activation perturbed the mitochondrial dynamics, increased the synaptic plasticity after 21 days of treatment with Ast (10 mg/kg/day), and increased the expression of Aβ-degrading enzymes, mitochondrial fusion, and synapse-associated proteins and decreased the expression of mitochondrial fission proteins. Intraperitoneal injection of the mTOR inhibitor, rapamycin, abolished the effects of Ast. In conclusion, Ast activates the mTOR pathway, which is necessary for mitochondrial dynamics and synaptic plasticity, leading to improved learning and memory. Our results support the use of Ast for the treatment of cognitive deficits. Graphical abstract In summary, Ast ameliorates cognitive deficits via facilitating the mTOR-dependent mitochondrial dynamics and synaptic damage, and reducing Aβ accumulation. This model supports the use of Ast for the treatment of cognitive deficits.

Effect of Cladribine on Neuronal Apoptosis: New Insight of In Vitro Study in Multiple Sclerosis Therapy

Background: Cladribine (2-CdA) can cross the blood–brain barrier, resulting in inhibition of DNA synthesis and repair and disruption of cellular proliferation in actively dividing lymphocytes. No data on effect on neurons are available. Aim: To study “in vitro” 2-CdA apoptotic effects on neurons in healthy donor and multiple sclerosis patient lymphocytes. Methods: Neuroblastoma cells were co-cultured with lymphocytes, with and without 2-CdA. Results: Apoptosis increased in lymphocytes with 2-CdA; increase was also observed when lymphocytes were cultured with neuronal cells. However, neurons were not affected by 2-CdA for apoptosis. Conclusions: 2-CdA causes peripheral and central lymphocyte death preserving neurons, with a reasonable impact on inflammation and neuroprotection.

Structures of Astaxanthin and Their Consequences for Therapeutic Application

Reactive oxygen species (ROS) are continuously generated as a by-product of normal aerobic metabolism. Elevated ROS formation leads to potential damage of biological structures and is implicated in various diseases. Astaxanthin, a xanthophyll carotenoid, is a secondary metabolite responsible for the red-orange color of a number of marine animals and microorganisms. There is mounting evidence that astaxanthin has powerful antioxidant, anti-inflammatory, and antiapoptotic activities. Hence, its consumption can result in various health benefits, with potential for therapeutic application. Astaxanthin contains both a hydroxyl and a keto group, and this unique structure plays important roles in neutralizing ROS. The molecule quenches harmful singlet oxygen, scavenges peroxyl and hydroxyl radicals and converts them into more stable compounds, prevents the formation of free radicals, and inhibits the autoxidation chain reaction. It also acts as a metal chelator and converts metal prooxidants into harmless molecules. However, like many other carotenoids, astaxanthin is affected by the environmental conditions, e.g., pH, heat, or exposure to light. It is hence susceptible to structural modification, i.e., via isomerization, aggregation, or esterification, which alters its physiochemical properties. Here, we provide a concise overview of the distribution of astaxanthin in tissues, and astaxanthin structures, and their role in tackling singlet oxygen and free radicals. We highlight the effect of structural modification of astaxanthin molecules on the bioavailability and biological activity. These studies suggested that astaxanthin would be a promising dietary supplement for health applications.

Astaxanthin Counteracts Excitotoxicity and Reduces the Ensuing Increases in Calcium Levels and Mitochondrial Reactive Oxygen Species Generation

Astaxanthin (ASX) is a carotenoid pigment with strong antioxidant properties. We have reported previously that ASX protects neurons from the noxious effects of amyloid-β peptide oligomers, which promote excessive mitochondrial reactive oxygen species (mROS) production and induce a sustained increase in cytoplasmic Ca²⁺ concentration. These properties make ASX a promising therapeutic agent against pathological conditions that entail oxidative and Ca²⁺ dysregulation. Here, we studied whether ASX protects neurons from N-methyl-D-aspartate (NMDA)-induced excitotoxicity, a noxious process which decreases cellular viability, alters gene expression and promotes excessive mROS production. Incubation of the neuronal cell line SH-SY5Y with NMDA decreased cellular viability and increased mitochondrial superoxide production; pre-incubation with ASX prevented these effects. Additionally, incubation of SH-SY5Y cells with ASX effectively reduced the basal mROS production and prevented hydrogen peroxide-induced cell death. In primary hippocampal neurons, transfected with a genetically encoded cytoplasmic Ca²⁺ sensor, ASX also prevented the increase in intracellular Ca²⁺ concentration induced by NMDA. We suggest that, by preventing the noxious mROS and Ca²⁺ increases that occur under excitotoxic conditions, ASX could be useful as a therapeutic agent in neurodegenerative pathologies that involve alterations in Ca²⁺ homeostasis and ROS generation.

Effect of Astaxanthin on Activation of Autophagy and Inhibition of Apoptosis in Helicobacter pylori-Infected Gastric Epithelial Cell Line AGS

Helicobacter pylori (H. pylori) infection leads to the massive apoptosis of the gastric epithelial cells, causing gastric ulcers, gastritis, and gastric adenocarcinoma. Autophagy is a cellular recycling process that plays important roles in cell death decisions and can protect cells by preventing apoptosis. Upon the induction of autophagy, the level of the autophagy substrate p62 is reduced and the autophagy-related ratio of microtubule-associated proteins 1A/1B light chain 3B (LC3B)-II/LC3B-I is heightened. AMP-activated protein kinase (AMPK) and mammalian target of rapamycin (mTOR) are involved in the regulation of autophagy. Astaxanthin (AST) is a potent anti-oxidant that plays anti-inflammatory and anti-cancer roles in various cells. In the present study, we examined whether AST inhibits H. pylori-induced apoptosis through AMPK-mediated autophagy in the human gastric epithelial cell line AGS (adenocarcinoma gastric) in vitro. In this study, H. pylori induced apoptosis. Compound C, an AMPK inhibitor, enhanced the H. pylori-induced apoptosis of AGS cells. In contrast, metformin, an AMPK activator, suppressed H. pylori-induced apoptosis, showing that AMPK activation inhibits H. pylori-induced apoptosis. AST inhibited H. pylori-induced apoptosis by increasing the phosphorylation of AMPK and decreasing the phosphorylation of RAC-alpha serine/threonine-protein kinase (Akt) and mTOR in H. pylori-stimulated cells. The number of LC3B puncta in H. pylori-stimulated cells increased with AST. These results suggest that AST suppresses the H. pylori-induced apoptosis of AGS cells by inducing autophagy through the activation of AMPK and the downregulation of its downstream target, mTOR. In conclusion, AST may inhibit gastric diseases associated with H. pylori infection by increasing autophagy through the activation of the AMPK pathway.

Nutraceuticals Targeting Generation and Oxidant Activity of Peroxynitrite May Aid Prevention and Control of Parkinson's Disease

Parkinson's disease (PD) is a chronic low-grade inflammatory process in which activated microglia generate cytotoxic factors-most prominently peroxynitrite-which induce the death and dysfunction of neighboring dopaminergic neurons. Dying neurons then release damage-associated molecular pattern proteins such as high mobility group box 1 which act on microglia via a range of receptors to amplify microglial activation. Since peroxynitrite is a key mediator in this process, it is proposed that nutraceutical measures which either suppress microglial production of peroxynitrite, or which promote the scavenging of peroxynitrite-derived oxidants, should have value for the prevention and control of PD. Peroxynitrite production can be quelled by suppressing activation of microglial NADPH oxidase-the source of its precursor superoxide-or by down-regulating the signaling pathways that promote microglial expression of inducible nitric oxide synthase (iNOS). Phycocyanobilin of spirulina, ferulic acid, long-chain omega-3 fatty acids, good vitamin D status, promotion of hydrogen sulfide production with taurine and N-acetylcysteine, caffeine, epigallocatechin-gallate, butyrogenic dietary fiber, and probiotics may have potential for blunting microglial iNOS induction. Scavenging of peroxynitrite-derived radicals may be amplified with supplemental zinc or inosine. Astaxanthin has potential for protecting the mitochondrial respiratory chain from peroxynitrite and environmental mitochondrial toxins. Healthful programs of nutraceutical supplementation may prove to be useful and feasible in the primary prevention or slow progression of pre-existing PD. Since damage to the mitochondria in dopaminergic neurons by environmental toxins is suspected to play a role in triggering the self-sustaining inflammation that drives PD pathogenesis, there is also reason to suspect that plant-based diets of modest protein content, and possibly a corn-rich diet high in spermidine, might provide protection from PD by boosting protective mitophagy and thereby aiding efficient mitochondrial function. Low-protein diets can also promote a more even response to levodopa therapy.

Astaxanthin Prevents Mitochondrial Impairment Induced by Isoproterenol in Isolated Rat Heart Mitochondria

Mitochondria are considered to be a power station of the cell. It is known that they play a major role in both normal and pathological heart function. Alterations in mitochondrial bioenergetics are one of the main causes of the origin and progression of heart failure since they have an inhibitory effect on the activity of respiratory complexes in the inner mitochondrial membrane. Astaxanthin (AST) is a xanthophyll carotenoid of mainly marine origin. It has both lipophilic and hydrophilic properties and may prevent mitochondrial dysfunction by permeating the cell membrane and co-localizing within mitochondria. The carotenoid suppresses oxidative stress-induced mitochondrial dysfunction and the development of diseases. In the present study, it was found that the preliminary oral administration of AST upregulated the activity of respiratory chain complexes and ATP synthase and the level of their main subunits, thereby improving the respiration of rat heart mitochondria (RHM) in the heart injured by isoproterenol (ISO). AST decreased the level of cyclophilin D (CyP-D) and increased the level of adenine nucleotide translocase (ANT) in this condition. It was concluded that AST could be considered as a potential mitochondrial-targeted agent in the therapy of pathological conditions associated with oxidative damage and mitochondrial dysfunction. AST, as a dietary supplement, has a potential in the prevention of cardiovascular diseases.

Biologically Active Echinulin-Related Indolediketopiperazines from the Marine Sediment-Derived Fungus Aspergillus niveoglaucus

Seven known echinulin-related indolediketopiperazine alkaloids (1–7) were isolated from the Vietnamese sediment-derived fungus Aspergillus niveoglaucus. Using chiral HPLC, the enantiomers of cryptoechinuline B (1) were isolated as individual compounds for the first time. (+)-Cryptoechinuline B (1a) exhibited neuroprotective activity in 6-OHDA-, paraquat-, and rotenone-induced in vitro models of Parkinson’s disease. (−)-Cryptoechinuline B (1b) and neoechinulin C (5) protected the neuronal cells against paraquat-induced damage in a Parkinson’s disease model. Neoechinulin B (4) exhibited cytoprotective activity in a rotenone-induced model, and neoechinulin (7) showed activity in the 6-OHDA-induced model.

Astaxanthin Suppresses Cigarette Smoke-Induced Emphysema through Nrf2 Activation in Mice

Oxidative stress plays an important role in the pathogenesis of chronic obstructive pulmonary disease (COPD). The activation of nuclear factor erythroid 2-related factor 2 (Nrf2) is a key cellular defense mechanism against oxidative stress. Recent studies have shown that astaxanthin protects against oxidative stress via Nrf2. In this study, we investigated the emphysema suppression effect of astaxanthin via Nrf2 in mice. Mice were divided into four groups: control, smoking, astaxanthin, and astaxanthin + smoking. The mice in the smoking and astaxanthin + smoking groups were exposed to cigarette smoke for 12 weeks, and the mice in the astaxanthin and astaxanthin + smoking groups were fed a diet containing astaxanthin. Significantly increased expression levels of Nrf2 and its target gene, heme oxygenase-1 (HO-1), were found in the lung homogenates of astaxanthin-fed mice. The number of inflammatory cells in the bronchoalveolar lavage fluid (BALF) was significantly decreased, and emphysema was significantly suppressed. In conclusion, astaxanthin protects against oxidative stress via Nrf2 and ameliorates cigarette smoke-induced emphysema. Therapy with astaxanthin directed toward activating the Nrf2 pathway has the potential to be a novel preventive and therapeutic strategy for COPD.

Ultrafast Simultaneous Raman-Fluorescence Spectroscopy

Raman and fluorescence spectroscopies offer complementary approaches in bioanalytical chemistry, particularly in microbiological assays. The former method is used to detect lipids, metabolites, and nonspecific proteins and nucleic acids in a label-free manner, while the latter is used to investigate targeted proteins, nucleic acids, and their interactions via labeling or transfection. Despite their complementarity, these regimes are seldom used in conjunction due to fluorescent signals overwhelming inherently weak Raman signals by more than several orders of magnitude. Here we report a multimodal spectrometer that simultaneously performs Raman and fluorescence spectroscopies at high speed. It is made possible by Fourier-transform-coherent anti-Stokes Raman scattering (FT-CARS) and Fourier-transform-two-photon excitation (FT-TPE) measurements powered by a femtosecond pulse laser coupled to a homemade rapid-scan Michelson interferometer, operating at 24 000 spectra per second. As a proof-of-principle demonstration, we validate the ultrafast fluoRaman spectrometer by measuring coumarin dyes in organic solvents. To show its potential for applications that require rapid fluoRaman spectroscopy, we also demonstrate fluoRaman flow cytometry of Haematococcus pluvialis cells under varying culture conditions with a high throughput of ∼10 events per second to perform large-scale single-cell analysis of their metabolic stress response.