Astaxanthin Ameliorates Lipopolysaccharide-Induced Neuroinflammation, Oxidative Stress and Memory Dysfunction through Inactivation of the Signal Transducer and Activator of Transcription 3 Pathway

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.

Research progress on the protection and mechanism of active peptides in Alzheimer's disease and Parkinson's disease

Neurodegenerative diseases are the main causes of death and morbidity among elderly people worldwide. From the pathological point of view, oxidative stress, neuroinflammation, mitochondrial damage and apoptosis are the causes of neuronal diseases, and play a harmful role in the process of neuronal cell death and neurodegeneration. The most common neurodegenerative diseases are Alzheimer's disease(AD) and Parkinson's disease(PD), and there is no effective treatment. The physiological role of active peptides in the human body is significant. Modern medical research has found that animal and plant peptides, natural peptides in human body, can act on the central nervous system, and their active components can improve learning and memory ability, and play the roles of antioxidation, anti-inflammation, anti-apoptosis and maintaining the structure and function of mitochondria. This review reviews the reports on neurodegenerative diseases such as AD and PD by active peptides from animals and plants and natural peptides from the human body, and summarizes the neuroprotective mechanism of peptides. A theoretical basis for further research and development of active peptides was provided by examining the research and application of peptides, which provided a theoretical basis for further research and development.

Marine Pharmacology in 2019-2021: Marine Compounds with Antibacterial, Antidiabetic, Antifungal, Anti-Inflammatory, Antiprotozoal, Antituberculosis and Antiviral Activities; Affecting the Immune and Nervous Systems, and Other Miscellaneous Mechanisms of Action

The current 2019-2021 marine pharmacology literature review provides a continuation of previous reviews covering the period 1998 to 2018. Preclinical marine pharmacology research during 2019-2021 was published by researchers in 42 countries and contributed novel mechanism-of-action pharmacology for 171 structurally characterized marine compounds. The peer-reviewed marine natural product pharmacology literature reported antibacterial, antifungal, antiprotozoal, antituberculosis, and antiviral mechanism-of-action studies for 49 compounds, 87 compounds with antidiabetic and anti-inflammatory activities that also affected the immune and nervous system, while another group of 51 compounds demonstrated novel miscellaneous mechanisms of action, which upon further investigation, may contribute to several pharmacological classes. Thus, in 2019-2021, a very active preclinical marine natural product pharmacology pipeline provided novel mechanisms of action as well as new lead chemistry for the clinical marine pharmaceutical pipeline targeting the therapy of several disease categories.

The preventive effects of Saccharomyces boulardii against oxidative stress induced by lipopolysaccharide in rat brain

The brain is sensitive to oxidative stress, which can trigger microglial activation and neuroinflammation. Antioxidant therapies may provide neuroprotection against oxidative stress. In recent years antioxidant effects of probiotics and their possible mechanisms in oxidative stress-related models have been determined. In the current study, for the first time, we assessed the effects of Saccharomyces boulardii on oxidative stress provoked by lipopolysaccharide (LPS) in the rat brain. Four groups of animals were used, including the control, LPS, S. boulardii + LPS, and S. boulardii groups. All animals received either saline or S. boulardii (1010 CFU) by gavage for four weeks. Between days 14 and 22, all animals received either LPS (250 μg/kg) or saline by intraperitoneal (i.p.) injection. S. boulardii was able to inhibit lipid peroxidation and prevent the reduction of antioxidant levels, including glutathione and catalase in the model of oxidative stress induced by LPS in the rat hippocampus and cortex. Also, it increased the lowered ratio of glutathione/oxidized glutathione in both tissues. Serum levels of anti-inflammatory interleukin 10 (IL-10) and proinflammatory cytokines IL-6 and IL-8 increased and decreased, respectively. S. boulardii has potential antioxidant activities in oxidative stress-related model, possibly modulating gut microbiota, immune defense, and antioxidant enzyme activities that can be considered in preventing oxidative stress-related central nervous system (CNS) diseases.

Doxycycline-Loaded Calcium Phosphate Nanoparticles with a Pectin Coat Can Ameliorate Lipopolysaccharide-Induced Neuroinflammation Via Enhancing AMPK

Neuroinflammation occurs in response to different injurious triggers to limit their hazardous effects. However, failure to stop this process can end in multiple neurological diseases. Doxycycline (DX) is a tetracycline, with potential antioxidant and anti-inflammatory properties. The current study tested the effects of free DX, DX-loaded calcium phosphate (DX@CaP), and pectin-coated DX@CaP (Pec/DX@CaP) nanoparticles on the lipopolysaccharide (LPS)-induced neuroinflammation in mice and to identify the role of adenosine monophosphate-activated protein kinase (AMPK) in this effect. The present study was conducted on 48 mice, divided into 6 groups, eight mice each. Group 1 (normal control), Group 2 (blank nanoparticles-treated), Group 3 (LPS (untreated)), Groups 4, 5, and 6 received LPS, then Group 4 received free DX, Group 5 received DX-loaded calcium phosphate nanoparticles (DX@CaP), and Group 6 received DX-loaded calcium phosphate nanoparticles with a pectin coat (Pec/DX@CaP). At the end of the experimentation period, behavioral tests were carried out. Then, mice were sacrificed, and brain tissue was extracted and used for histological examination, and assessment of interleukin-6 positive cells in different brain areas, in addition to biochemical measurement of SOD activity, TLR-4, AMPK and Nrf2. LPS can induce prominent neuroinflammation. Treatment with (Pec/DX@CaP) can reverse most behavioral, histopathological, and biochemical changes caused by LPS. The findings of the current study suggest that (Pec/DX@CaP) exerts a significant reverse of LPS-induced neuroinflammation by enhancing SOD activity, AMPK, and Nrf2 expression, in addition to suppression of TLR-4.

Docosahexaenoic Acid-Acylated Astaxanthin Monoester Ameliorates Amyloid-β Pathology and Neuronal Damage by Restoring Autophagy in Alzheimer's Disease Models

SCOPE

Astaxanthin (AST) is ubiquitous in aquatic foods and microorganisms. The study previously finds that docosahexaenoic acid-acylated AST monoester (AST-DHA) improves cognitive function in Alzheimer's disease (AD), although the underlying mechanism remains unclear. Moreover, autophagy is reportedly involved in amyloid-β (Aβ) clearance and AD pathogenesis. Therefore, this study aims to evaluate the preventive effect of AST-DHA and elucidates the mechanism of autophagy modulation in Aβ pathology.

METHODS AND RESULTS

In the cellular AD model, AST-DHA significantly reduces toxic Aβ1-42 levels and alleviated the accumulation of autophagic markers (LC3II/I and p62) in Aβ25-35 -induced SH-SY5Y cells. Notably, AST-DHA restores the autophagic flux in SH-SY5YmRFP-GFP-LC3 cells. In APP/PS1 mice, a 3-month dietary supplementation of AST-DHA exceeded free-astaxanthin (F-AST) capacity to increase hippocampal and cortical autophagy. Mechanistically, AST-DHA restores autophagy by activating the ULK1 signaling pathway and restoring autophagy-lysosome fusion. Moreover, AST-DHA relieves ROS production and mitochondrial stress affecting autophagy in AD. As a favorable outcome of restored autophagy, AST-DHA mitigates cerebral Aβ and p-Tau deposition, ultimately improving neuronal function.

CONCLUSION

The findings demonstrate that AST-DHA can rectify autophagic impairment in AD, and confer neuroprotection in Aβ-related pathology, which supports the future application of AST as an autophagic inducer for maintaining brain health.

A systematic review for the development of Alzheimer's disease in in vitro models: a focus on different inducing agents

Alzheimer's disease (AD) is the most common progressive neurodegenerative disease and is associated with dementia. Presently, various chemical and environmental agents are used to induce in-vitro models of Alzheimer disease to investigate the efficacy of different therapeutic drugs. We screened literature from databases such as PubMed, ScienceDirect, and Google scholar, emphasizing the diverse targeting mechanisms of neuro degeneration explored in in-vitro models. The results revealed studies in which different types of chemicals and environmental agents were used for in-vitro development of Alzheimer-targeting mechanisms of neurodegeneration. Studies using chemically induced in-vitro AD models included in this systematic review will contribute to a deeper understanding of AD. However, none of these models can reproduce all the characteristics of disease progression seen in the majority of Alzheimer's disease subtypes. Additional modifications would be required to replicate the complex conditions of human AD in an exact manner. In-vitro models of Alzheimer's disease developed using chemicals and environmental agents are instrumental in providing insights into the disease's pathophysiology; therefore, chemical-induced in-vitro AD models will continue to play vital role in future AD research. This systematic screening revealed the pivotal role of chemical-induced in-vitro AD models in advancing our understanding of AD pathophysiology and is therefore important to understand the potential of these chemicals in AD pathogenesis.

Dietary Astaxanthin: A Promising Antioxidant and Anti-Inflammatory Agent for Brain Aging and Adult Neurogenesis

Decreased adult neurogenesis, or the gradual depletion of neural stem cells in adult neurogenic niches, is considered a hallmark of brain aging. This review provides a comprehensive overview of the intricate relationship between aging, adult neurogenesis, and the potential neuroregenerative properties of astaxanthin, a carotenoid principally extracted from the microalga Haematococcus pluvialis. The unique chemical structure of astaxanthin enables it to cross the blood-brain barrier and easily reach the brain, where it may positively influence adult neurogenesis. Astaxanthin can affect molecular pathways involved in the homeostasis, through the activation of FOXO3-related genetic pathways, growth, and regeneration of adult brain neurons, enhancing cell proliferation and the potency of stem cells in neural progenitor cells. Furthermore, astaxanthin appears to modulate neuroinflammation by suppressing the NF-κB pathway, reducing the production of pro-inflammatory cytokines, and limiting neuroinflammation associated with aging and chronic microglial activation. By modulating these pathways, along with its potent antioxidant properties, astaxanthin may contribute to the restoration of a healthy neurogenic microenvironment, thereby preserving the activity of neurogenic niches during both normal and pathological aging.

Inflammatory signaling pathways in the treatment of Alzheimer's disease with inhibitors, natural products and metabolites (Review)

The intricate nature of Alzheimer's disease (AD) pathogenesis poses a persistent obstacle to drug development. In recent times, neuroinflammation has emerged as a crucial pathogenic mechanism of AD, and the targeting of inflammation has become a viable approach for the prevention and management of AD. The present study conducted a comprehensive review of the literature between October 2012 and October 2022, identifying a total of 96 references, encompassing 91 distinct pharmaceuticals that have been investigated for their potential impact on AD by inhibiting neuroinflammation. Research has shown that pharmaceuticals have the potential to ameliorate AD by reducing neuroinflammation mainly through regulating inflammatory signaling pathways such as NF‑κB, MAPK, NLRP3, PPARs, STAT3, CREB, PI3K/Akt, Nrf2 and their respective signaling pathways. Among them, tanshinone IIA has been extensively studied for its anti‑inflammatory effects, which have shown significant pharmacological properties and can be applied clinically. Thus, it may hold promise as an effective drug for the treatment of AD. The present review elucidated the inflammatory signaling pathways of pharmaceuticals that have been investigated for their therapeutic efficacy in AD and elucidates their underlying mechanisms. This underscores the auspicious potential of pharmaceuticals in ameliorating AD by impeding neuroinflammation.

TRIM62 knockdown by inhibiting the TLR4/NF-κB pathway and NLRP3 inflammasome attenuates cognitive impairment induced by diabetes in mice

The tripartite motif 62 is an E3 ubiquitin ligase protein that regulates cellular processes, including differentiation, immunity, development and apoptosis, leading to various disease states, such as cancer and inflammatory diseases. However, the role and mechanism of the tripartite motif 62 in the process of diabetic-induced cognitive impairment have not been reported. Therefore, the aim of this study was to investigate the role and mechanism of the tripartite motif 62 in diabetic-induced cognitive impairment. The results showed that the expression of the tripartite motif 62 was up-regulated in diabetic mice. Silencing of TRIM62 increased body weight and decreased fasting blood glucose in diabetic mice. In addition, knockdown of the tripartite motif 62 inhibited STZ-induced inflammation, apoptosis and oxidative stress. Further studies showed that the TLR4/NF-κB pathway and NLRP3 inflammasomes were involved in the regulation of diabetic mice by the tripartite motif 62. More importantly, inhibition of the tripartite motif 62 improved cognitive impairment and learning ability in mice. In conclusion, inhibition of TRIM62 inhibits STZ-induced inflammation, cell apoptosis and oxidative stress, and improves the cognitive ability of mice. Therefore, the tripartite motif 62 may be an important target for the treatment of diabetes-induced cognitive impairment.

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.

Preventive Treatment with Astaxanthin Microencapsulated with Spirulina Powder, Administered in a Dose Range Equivalent to Human Consumption, Prevents LPS-Induced Cognitive Impairment in Rats

Cognitive alterations are a common feature associated with many neurodegenerative diseases and are considered a major health concern worldwide. Cognitive alterations are triggered by microglia activation and oxidative/inflammatory processes in specific areas of the central nervous system. Consumption of bioactive compounds with antioxidative and anti-inflammatory effects, such as astaxanthin and spirulina, can help in preventing the development of these pathologies. In this study, we have investigated the potential beneficial neuroprotective effects of a low dose of astaxanthin (ASX) microencapsulated within spirulina (ASXSP) in female rats to prevent the cognitive deficits associated with the administration of LPS. Alterations in memory processing were evaluated in the Y-Maze and Morris Water Maze (MWM) paradigms. Changes in microglia activation and in gut microbiota content were also investigated. Our results demonstrate that LPS modified long-term memory in the MWM and increased microglia activation in the hippocampus and prefrontal cortex. Preventive treatment with ASXSP ameliorated LPS-cognitive alterations and microglia activation in both brain regions. Moreover, ASXSP was able to partially revert LPS-induced gut dysbiosis. Our results demonstrate the neuroprotective benefits of ASX when microencapsulated with spirulina acting through different mechanisms, including antioxidant, anti-inflammatory and, probably, prebiotic actions.

4-Octyl itaconate attenuates LPS-induced acute kidney injury by activating Nrf2 and inhibiting STAT3 signaling

BACKGROUND

Septic acute kidney injury (S-AKI) is the leading form of acute kidney failure among hospitalized patients, and the inflammatory response is involved in this process. 4-octyl itaconate (4-OI) is a multi-target itaconate derivative with potent anti-inflammatory action. However, it remains elusive whether and how 4-OI contributes to the regulation of S-AKI.

METHODS

We employed a lipopolysaccharide (LPS)-induced AKI murine model and explored the potential renoprotective effect of 4-OI in vivo. In vitro experiments, BUMPT cells, a murine renal tubular cell line, were conducted to examine the effects of 4-OI on inflammation, oxidative stress, and mitophagy. Moreover, STAT3 plasmid was transfected in BUMPT cells to investigate the role of STAT3 signaling in the 4-OI-administrated state.

RESULTS

We demonstrate that 4-OI protects against S-AKI through suppressing inflammation and oxidative stress and enhancing mitophagy. 4-OI significantly reduced the levels of Scr, BUN, Ngal as well as the tubular injury in LPS-induced AKI mice. 4-OI restrained inflammation by reducing macrophage infiltration and suppressing the expression of IL-1β and NLRP3 in the septic kidney. 4-OI also reduced ROS levels, as well as cleaved caspase-3 and boosted antioxidants such as HO-1, and NQO1 in mice. In addition, the 4-OI treatment significantly promoted mitophagy. Mechanistically, 4-OI activated Nrf2 signaling and suppressed phosphorylated STAT3 in vivo and vitro. Molecular docking revealed the binding affinity of 4-OI towards STAT3. ML385, a specific Nrf2 inhibitor, partially repressed the anti-inflammatory and anti-oxidative effects of 4-OI and partially restricted the mitophagy induced by 4-OI in vivo and in vitro. Transfected with STAT3 plasmid partially suppressed mitophagy and the anti-inflammatory effect provoked by 4-OI in vitro.

CONCLUSION

These data suggest that 4-OI ameliorates LPS-induced AKI by suppressing inflammation and oxidative stress and enhancing mitophagy through the overactivation of the Nrf2 signaling pathway, and inactivation of STAT3. Our study identifies 4-OI as a promising pharmacologic for S-AKI.

Metabolite analysis of soybean oil on promoting astaxanthin production of Phaffia rhodozyma

BACKGROUND

Astaxanthin is a carotenoid with strong antioxidant property. In addition, it has anti-cancer, anti-tumor, anti-inflammatory and many other functions. The micro-organisms that mainly produce astaxanthin are Haematococcus pluvialis and Phaffia rhodozyma. Compared with H. pluvialis, P. rhodozyma has shorter fermentation cycle and easier to control culture conditions, but the yield of astaxanthin in P. rhodozyma is low. This article studied how to improve the astaxanthin production of P. rhodozyma.

RESULTS

The results showed that when 10 mL L^-1 soybean oil was added to the culture medium, astaxanthin production increased significantly, reaching 7.35 mg L^-1 , which was 1.4 times that of the control group, and lycopene and β-carotene contents also increased significantly. Through targeted metabolite analysis, the fatty acids in P. rhodozyma significantly increased under the soybean oil stimulation, especially the fatty acids closely related to the formation of astaxanthin esters, included palmitic acid (C16:0), stearic acid (C18:0), oleic acid (C18:1n9), linoleic acid (C18:2n6), α-linolenic acid (C18:3n3) and γ-linolenic acid (C18:3n6), thereby increasing the astaxanthin esters content.

CONCLUSION

It showed that the addition of soybean oil can promote the accumulation of astaxanthin by promoting the increase of astaxanthin ester content. © 2022 Society of Chemical Industry.

KDM4A, involved in the inflammatory and oxidative stress caused by traumatic brain injury-hemorrhagic shock, partly through the regulation of the microglia M1 polarization

BACKGROUND

Microglial polarization and the subsequent neuroinflammatory response and oxidative stress are contributing factors for traumatic brain injury (TBI) plus hemorrhagic shock (HS) induced brain injury. In the present work, we have explored whether Lysine (K)-specific demethylase 4 A (KDM4A) modulates microglia M1 polarization in the TBI and HS mice.

RESULTS

Male C57BL/6J mice were used to investigate the microglia polarization in the TBI + HS model in vivo. Lipopolysaccharide (LPS)-induced BV2 cells were used to examine the mechanism of KDM4A in regulating microglia polarization in vitro. We found that TBI + HS resulted in neuronal loss and microglia M1 polarization in vivo, reflected by the increased level of Iba1, tumor necrosis factor (TNF)-α, interleukin (IL)-1β, malondialdehyde (MDA) and the decreased level of reduced glutathione (GSH). Additionally, KDM4A was upregulated in response to TBI + HS and microglia were among the cell types showing the increased level of KDM4A. Similar to the results in vivo, KDM4A also highly expressed in LPS-induced BV2 cells. LPS-induced BV2 cells exhibited enhanced microglia M1 polarization, and enhanced level of pro-inflammatory cytokines, oxidative stress and reactive oxygen species (ROS), while this enhancement was abolished by the suppression of KDM4A.

CONCLUSION

Accordingly, our findings indicated that KDM4A was upregulated in response to TBI + HS and microglia were among the cell types showing the increased level of KDM4A. The important role of KDM4A in TBI + HS-induced inflammatory response and oxidative stress was at least partially realized through regulating microglia M1 polarization.

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

Background

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

Purpose

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

Methods

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

Results

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

Conclusion

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

Turmeronols (A and B) from Curcuma longa have anti-inflammatory effects in lipopolysaccharide-stimulated BV-2 microglial cells by reducing NF-κB signaling

Turmeronols (A and B), bisabolane-type sesquiterpenoids found in turmeric, reduce inflammation outside the brain in animals; however, their effects on neuroinflammation, a common pathology of various neurodegenerative diseases, are not understood. Inflammatory mediators produced by microglial cells play a key role in neuroinflammation, so this study evaluated the anti-inflammatory effects of turmeronols in BV-2 microglial cells stimulated with lipopolysaccharide (LPS). Pretreatment with turmeronol A or B significantly inhibited LPS-induced nitric oxide (NO) production; mRNA expression of inducible NO synthase; production of interleukin (IL)-1β, IL-6, and tumor necrosis factor α and upregulation of their mRNA expression; phosphorylation of nuclear factor-κB (NF-κB) p65 proteins and inhibitor of NF-κB kinase (IKK); and nuclear translocation of NF-κB. These results suggest that these turmeronols may prevent the production of inflammatory mediators by inhibiting the IKK/NF-κB signaling pathway in activated microglial cells and can potentially treat neuroinflammation associated with microglial activation.

Mitochondrial dysfunctions, oxidative stress and neuroinflammation as therapeutic targets for neurodegenerative diseases: An update on current advances and impediments

Neurodegenerative diseases (NDs) such as Alzheimer disease (AD), Parkinson disease (PD), and Huntington disease (HD) represent a major socio-economic challenge in view of their high prevalence yet poor treatment outcomes affecting quality of life. The major challenge in drug development for these NDs is insufficient clarity about the mechanisms involved in pathogenesis and pathophysiology. Mitochondrial dysfunction, oxidative stress and inflammation are common pathways that are linked to neuronal abnormalities and initiation of these diseases. Thus, elucidating the shared initial molecular and cellular mechanisms is crucial for recognizing novel remedial targets, and developing therapeutics to impede or stop disease progression. In this context, use of multifunctional compounds at early stages of disease development unclogs new avenues as it acts on act on multiple targets in comparison to single target concept. In this review, we summarize overview of the major findings and advancements in recent years focusing on shared mechanisms for better understanding might become beneficial in searching more potent pharmacological interventions thereby reducing the onset or severity of various NDs.

Hizikia fusiforme functional oil (HFFO) prevents neuroinflammation and memory deficits evoked by lipopolysaccharide/aluminum trichloride in zebrafish

Background

Oxidative stress, cholinergic deficiency, and neuroinflammation are hallmarks of most neurodegenerative disorders (NDs). Lipids play an important role in brain development and proper functioning. Marine-derived lipids have shown good memory-improving potentials, especially those from fish and microalgae. The cultivated macroalga Hizikia fusiforme is healthy food and shows benefits to memory, but the study is rare on the brain healthy value of its oil. Previously, we had reported that the Hizikia fusiforme functional oil (HFFO) contains arachidonic acid, 11,14,17-eicosatrienoic acid, phytol, and other molecules displaying in vitro acetylcholinesterase inhibitory and nitroxide scavenging activity; however, the in vivo effect remains unclear. In this study, we further investigated its potential effects against lipopolysaccharides (LPS)- or aluminum trichloride (AlCl3)-induced memory deficiency in zebrafish and its drug-related properties in silica.

Methods

We established memory deficit models in zebrafish by intraperitoneal (i.p.) injection of lipopolysaccharides (LPS) (75 ng) or aluminum trichloride (AlCl3) (21 μg), and assessed their behaviors in the T-maze test. The interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), acetylcholine (ACh), and malondialdehyde (MDA) levels were measured 24 h after the LPS/AlCl3 injection as markers of inflammation, cholinergic activity, and oxidative stress. Furthermore, the interaction of two main components, 11,14,17-eicosatrienoic acid and phytol, was investigated by molecular docking, with the important anti-inflammatory targets nuclear factor kappa B (NF-κB) and cyclooxygenase 2 (COX-2). Specifically, the absorption, distribution, metabolism, excretion, and toxicity (ADMET) and drug-likeness properties of HFFO were studied by ADMETlab.

Results

The results showed that HFFO reduced cognitive deficits in zebrafish T-maze induced by LPS/AlCl3. While the LPS/AlCl3 treatment increased MDA content, lowered ACh levels in the zebrafish brain, and elevated levels of central and peripheral proinflammatory cytokines, these effects were reversed by 100 mg/kg HFFO except for MDA. Moreover, 11,14,17-eicosatrienoic acid and phytol showed a good affinity with NF-κB, COX-2, and HFFO exhibited acceptable drug-likeness and ADMET profiles in general.

Conclusion

Collectively, this study's findings suggest HFFO as a potent neuroprotectant, potentially valuable for the prevention of memory impairment caused by cholinergic deficiency and neuroinflammation.

Paradigm Shift in Phytochemicals Research: Evolution from Antioxidant Capacity to Anti-Inflammatory Effect and to Roles in Gut Health and Metabolic Syndrome

Food bioactive components, particularly phytochemicals with antioxidant capacity, have been extensively studied over the past two decades. However, as new analytical and molecular biological tools advance, antioxidants related research has undergone significant paradigm shifts. This review is a high-level overview of the evolution of phytochemical antioxidants research. Early research used chemical models to assess the antioxidant capacity of different phytochemicals, which provided important information about the health potential, but the results were overused and misinterpreted despite the lack of biological relevance (Antioxidants v1.0). This led to findings in the anti-inflammatory properties and modulatory effects of cell signaling of phytochemicals (Antioxidants v2.0). Recent advances in the role of diet in modulating gut microbiota have suggested a new phase of food bioactives research along the phytochemicals-gut microbiota-intestinal metabolites-low-grade inflammation-metabolic syndrome axis (Antioxidants v3.0). Polyphenols and carotenoids were discussed in-depth, and future research directions were also provided.

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.

Antioxidant Therapy in Oxidative Stress-Induced Neurodegenerative Diseases: Role of Nanoparticle-Based Drug Delivery Systems in Clinical Translation

Free radicals are formed as a part of normal metabolic activities but are neutralized by the endogenous antioxidants present in cells/tissue, thus maintaining the redox balance. This redox balance is disrupted in certain neuropathophysiological conditions, causing oxidative stress, which is implicated in several progressive neurodegenerative diseases. Following neuronal injury, secondary injury progression is also caused by excessive production of free radicals. Highly reactive free radicals, mainly the reactive oxygen species (ROS) and reactive nitrogen species (RNS), damage the cell membrane, proteins, and DNA, which triggers a self-propagating inflammatory cascade of degenerative events. Dysfunctional mitochondria under oxidative stress conditions are considered a key mediator in progressive neurodegeneration. Exogenous delivery of antioxidants holds promise to alleviate oxidative stress to regain the redox balance. In this regard, natural and synthetic antioxidants have been evaluated. Despite promising results in preclinical studies, clinical translation of antioxidants as a therapy to treat neurodegenerative diseases remains elusive. The issues could be their low bioavailability, instability, limited transport to the target tissue, and/or poor antioxidant capacity, requiring repeated and high dosing, which cannot be administered to humans because of dose-limiting toxicity. Our laboratory is investigating nanoparticle-mediated delivery of antioxidant enzymes to address some of the above issues. Apart from being endogenous, the main advantage of antioxidant enzymes is their catalytic mechanism of action; hence, they are significantly more effective at lower doses in detoxifying the deleterious effects of free radicals than nonenzymatic antioxidants. This review provides a comprehensive analysis of the potential of antioxidant therapy, challenges in their clinical translation, and the role nanoparticles/drug delivery systems could play in addressing these challenges.

Differential Expression of miR-381-3p in Alzheimer's Disease Patients and Its Role in Beta-Amyloid-Induced Neurotoxicity and Inflammation

INTRODUCTION

This study aimed to explore the diagnostic value and effect of miR-381-3p on Alzheimer's disease (AD).

METHODS

RT-qPCR was used for the measurement of miR-381-3p levels. Pearson correlation coefficient was used for the correlation analysis. Receiver operating characteristic (ROC) curve was constructed to assess the distinct ability of miR-381-3p for AD. SH-SY5Y cells were treated with Aβ25-35 to establish an AD cell model. The role of miR-381-3p on cell proliferation and apoptosis was detected. ELISA was applied to detect the protein levels of inflammatory cytokine expression. The target relationship of miR-381-3p with PTGS2 was verified by luciferase reporter gene assay.

RESULTS

Low expression of miR-381-3p was detected in the serum of AD patients and cell models. There was a negative association of serum miR-381-3p with the serum inflammatory cytokines. The ROC curve demonstrated the distinct ability of serum miR-381-3p for AD, with the AUC value of 0.898, with a sensitivity of 87.5%, and a specificity of 77.7%. Overexpression of miR-381-3p reversed the influence of Aβ25-35 on cell proliferation and apoptosis, but miR-381-3p downregulation exacerbated the influence. miR-381-3p overexpression inhibited the release of IL-6, IL-1β, and TNF-α induced by Aβ25-35 treatment, whereas miR-381-3p downregulation further promoted the release of inflammatory cytokines. PTGS2 was the target gene of miR-381-3p and was upregulated in AD cell models.

CONCLUSION

miR-381-3p is less expressed in the serum of AD patients and has potential diagnostic values for AD. Overexpression of miR-381-3p may attenuate Aβ25-35-induced neurotoxicity and inflammatory responses via targeting PTGS2 in SH-SY5Y cells.

A small molecule targeting CHI3L1 inhibits lung metastasis by blocking IL-13Rα2-mediated JNK-AP-1 signals

Our previous big data analyses showed a high level of association between chitinase 3 like1 (CHI3L1) expression and lung tumor development. In the present study, we investigated whether a CHI3L1‐inhibiting chemical, 2‐({3‐[2‐(1‐cyclohexen‐1‐yl)ethyl]‐6,7‐dimethoxy‐4‐oxo‐3,4‐dihydro‐2‐quinazolinyl}sulfanyl)‐N‐(4‐ethylphenyl)butanamide (K284), could inhibit lung metastasis and studied its mechanism of action. We investigated the antitumor effect of K284 both in vitro and in vivo. K284 (0.5 mg·kg⁻¹ body weight) significantly inhibited lung metastasis in in vivo models after injection of murine melanoma cells (B16F10) or adenocarcinomic human alveolar basal epithelial cells (A549). K284 significantly and concentration‐dependently also inhibited cancer cell proliferation and migration in the A549 and H460 lung cancer cell lines. We found that the binding of K284 to the chitin‐binding domain (CBD) of CHI3L1 prevented the binding of CHI3L1 to its receptor, interleukin‐13 receptor subunit alpha‐2 (IL‐13Rα2), thereby suppressing the CHI3L1 signal. This blocking of the CHI3L1‐IL‐13Rα2 signal caused the inhibition of c‐Jun N‐terminal kinase (JNK)‐activator protein 1 (AP‐1) signals, resulting in the prevention of lung metastasis and cancer cell growth. Our data demonstrate that K284 may serve as a potential candidate anticancer compound targeting CHI3L1.

The Circadian Rhythms of STAT3 in the Rat Pineal Gland and Its Involvement in Arylalkylamine-N-Acetyltransferase Regulation

In rodents, the melatonin production by the pineal gland is controlled through adrenergic signaling from the suprachiasmatic nuclei and regulation of the principal enzyme in its synthesis, arylalkylamine-N-acetyltransferase (AANAT). In the present study, we identified increased isoprenaline-induced aa-nat expression and nocturnal AANAT activity in the pineal glands in response to the silencing of the signal transducer and activator of transcription 3 (STAT3) with siRNA or STAT3 inhibitors WP1066 and AZD1480. This AANAT activity enhancement in vivo did not interfere with light-induced AANAT suppression. Systemic or in vitro lipopolysaccharide (LPS) administration markedly increased Stat3 expression and STAT3 phosphorylation, but it did not significantly affect AANAT expression or activity. Simultaneous LPS administration and Stat3 silencing enhanced the aa-nat transcription and AANAT activity to a similar extent as Stat3 inhibition without LPS co-administration. Furthermore, we describe the circadian rhythmicity in Stat3 expression and the phosphorylated form of STAT3 protein in the rat pineal gland. Our data suggest that the higher nocturnal endogenous level of STAT3 in the pineal gland decelerates or hampers the process of NA-induced AANAT activation or affects the AANAT enzyme stability.

Isoginkgetin treatment attenuated lipopolysaccharide-induced monoamine neurotransmitter deficiency and depression-like behaviors through downregulating p38/NF-κB signaling pathway and suppressing microglia-induced apoptosis

BACKGROUND

Microglia activation-induced neuroinflammation may contribute to the etiology of depression. Podocarpus nagi containing high concentration of isoginkgetin could effectively treat mental diseases in ancient times. However, the therapeutic role, peculiarly in the brain-immune modulation in depression is still unclear. This study aimed to determine effects of isoginkgetin on lipopolysaccharide (LPS)-induced depression-like changes. Furthermore, its modulation on the p38/nuclear factor-kappa B (NF-κB) pathway in LPS-activated microglia was evaluated.

METHODS

Adult Kunming mice were intraperitoneally injected vehicle or isoginkgetin (4 mg/kg) daily for 14 days before saline or LPS (0.83 mg/kg) administration. Depression-like behavior, neurotransmitter levels, and markers of neuroinflammation were determined. Isoginkgetin effect on LPS-induced microglial activation was then assessed in BV2 cells. Finally, conditioned medium (CM) derived from isoginkgetin-treated BV2 cells was co-cultured with SH-SY5Y cells for 24 h. Cell viability and apoptosis were evaluated.

RESULTS

LPS significantly induced helplessness and anxiety, which were associated with decreased 5-HT, noradrenaline, and dopamine concentrations. Meanwhile, LPS increased microglia M1 hallmark Iba1 expression and serum interleukin (IL)-1β concentration. These changes were attenuated by isoginkgetin treatment. In vitro, isoginkgetin markedly suppressed the production of IL-1β, IL-6, tumor necrosis factor-alpha, cyclooxygenase-2, inducible nitric oxide, and reactive oxygen species, which are released from LPS-stimulated BV2 cells. More interestingly, CM from isoginkgetin-treated BV2 cells significantly alleviated SH-SY5Y cell apoptosis and restored cell viability compared to LPS-treated group through the inhibition of p38/NF-κB signaling pathway.

CONCLUSION

These data demonstrate that isoginkgetin is an effective therapeutic agent for depression-like behaviors and neuropathological changes via potent anti-inflammatory property.

Anti-Inflammatory and Anticancer Effects of Microalgal Carotenoids

Acute inflammation is a key component of the immune system’s response to pathogens, toxic agents, or tissue injury, involving the stimulation of defense mechanisms aimed to removing pathogenic factors and restoring tissue homeostasis. However, uncontrolled acute inflammatory response may lead to chronic inflammation, which is involved in the development of many diseases, including cancer. Nowadays, the need to find new potential therapeutic compounds has raised the worldwide scientific interest to study the marine environment. Specifically, microalgae are considered rich sources of bioactive molecules, such as carotenoids, which are natural isoprenoid pigments with important beneficial effects for health due to their biological activities. Carotenoids are essential nutrients for mammals, but they are unable to synthesize them; instead, a dietary intake of these compounds is required. Carotenoids are classified as carotenes (hydrocarbon carotenoids), such as α- and β-carotene, and xanthophylls (oxygenate derivatives) including zeaxanthin, astaxanthin, fucoxanthin, lutein, α- and β-cryptoxanthin, and canthaxanthin. This review summarizes the present up-to-date knowledge of the anti-inflammatory and anticancer activities of microalgal carotenoids both in vitro and in vivo, as well as the latest status of human studies for their potential use in prevention and treatment of inflammatory diseases and cancer.

Platinum nanoparticles Protect Against Lipopolysaccharide-Induced Inflammation in Microglial BV-2 Cells via Decreased Oxidative Damage and Increased Phagocytosis

Neuroinflammation and oxidative stress cooperate to compromise the function of the central nervous system (CNS). Colloidal platinum nanoparticles (Pt NPs) are ideal candidates for reducing the deleterious effects of neuroinflammation since they act as free radical scavengers. Here we evaluated the effects of Pt NPs on several markers of lipopolysaccharide (LPS)-induced inflammation in cultured BV-2 microglial cells. BV-2 cells were treated with increased dilutions (1-100 ppm) of Colloidal Pt and/or LPS (1-10 µg/mL) at different exposure times. Three different protocols of exposure were used combining Pt NPs and LPS: (a) conditioning-protective effect (pre-post-treat), (b) therapeutic effect (co-treat) and (c) conditioning-therapeutic effect (pre-co-treat). After exposure to LPS for 24 h, cells were used for assessment of cell viability, reactive oxygen species (ROS) generation, lactate dehydrogenase (LDH) activity, apoptosis and caspase-3 levels, cell proliferation, mitochondrial membrane potential, inducible nitric oxide (iNOS) activity, pro-inflammatory cytokine (IL-1β, TNF-α and IL-6) levels, and phagocytic activity. Low concentrations (below or equal to 10 ppm) of Colloidal Pt prevented or ameliorated the LPS-induced increase in ROS formation, loss of mitochondrial membrane potential, induction of apoptosis, increase in LDH release, increase in pro-inflammatory cytokines and iNOS, inhibition of phagocytosis linked to microglial persistence in the M1 phase phenotype, loss of cell adhesion, differentiation and/or proliferation, as well as loss of cell viability. These protective effects were evident when cells were preconditioned with Pt NPs prior to LPS treatment. Collectively, the findings demonstrate that at low concentrations, Pt NPs can regulate the function and phenotype of BV-2 cells, activating protective mechanisms to maintain the microglial homeostasis and reduce inflammatory events triggered by the inflammatory insults induced by LPS. These preventive/protective effects on the LPS pro-inflammatory model are linked to the antioxidant properties and phagocytic activity of these NPs.

Hydrogen sulfide and mesenchymal stem cells-extracted microvesicles attenuate LPS-induced Alzheimer's disease

Both hydrogen sulfide (H2 S) and mesenchymal stem cells (MSCs) extracted microvesicles (MVs) are potent anti-inflammatory molecules. They play an essential role in lowering the production of tumor necrosis factor-alpha (TNF-α). The latter could strongly stimulate MiR-155 that contributes to neurodegeneration and Alzheimer's disease (AD). miR-155 could repress the expression of inositol 5-phosphatase-1 (SHIP-1) leading eventually to activation of Akt kinase and neurofibrillary development in AD. The current study was conducted to evaluate the role of miR-155 in a rat model of lipopolysaccharide (LPS)-induced AD and to investigate the effect of using MVs and H2 S that were given either separately or combined in regulating pro-inflammatory signaling. Thirty female Wistar albino rats aged 6 months to 1 year were equally divided into five groups; control group, LPS-induced AD group, LPS + MVs group, LPS + NaHS group, and LPS + MVs and NaHS group. The increased miR-155 level was associated with decreased SHIP-1 level and positively correlated with TNF-α. In addition, treatment with MVs and/or NaHS resulted in attenuation of inflammation, decreasing miR-155, pAkt levels, and downregulation of apoptosis along with improvement of the hippocampal and cortical histopathological alterations. LPS enhanced production of malondialdehyde (MDA) and reduced glutathione (GSH) levels indicating oxidative stress-induced neural damage, whereas MVs and NaHS could mitigate oxidative damage and accelerate antioxidant capacity via increasing catalase enzyme. In conclusion, downregulation of TNF-α, miR-155, and pAkt and increased SHIP-1 could improve the neuro-inflammatory state and cognitive function of LPS-induced Alzheimer's disease.

Evaluation of Anti-inflammatory Nutraceuticals in LPS-induced Mouse Neuroinflammation Model: An Update

It is known that peripheral infections, accompanied by inflammation, represent significant risk factors for the development of neurological disorders by modifying brain development or affecting normal brain aging. The acute effects of systemic inflammation on progressive and persistent brain damage and cognitive impairment are well documented. Anti-inflammatory therapies may have beneficial effects on the brain, and the protective properties of a wide range of synthetic and natural compounds have been extensively explored in recent years. In our previous review, we provided an extensive analysis of one of the most important and widely-used animal models of peripherally induced neuroinflammation and neurodegeneration - lipopolysaccharide (LPS)-treated mice. We addressed the data reproducibility in published research and summarized basic features and data on the therapeutic potential of various natural products, nutraceuticals, with known anti-inflammatory effects, for reducing neuroinflammation in this model. Here, recent data on the suitability of the LPS-induced murine neuroinflammation model for preclinical assessment of a large number of nutraceuticals belonging to different groups of natural products such as flavonoids, terpenes, non-flavonoid polyphenols, glycosides, heterocyclic compounds, organic acids, organosulfur compounds and xanthophylls, are summarized. Also, the proposed mechanisms of action of these molecules are discussed.

Astaxanthin protects against early acute kidney injury in severely burned rats by inactivating the TLR4/MyD88/NF-κB axis and upregulating heme oxygenase-1

Early acute kidney injury (AKI) contributes to severe morbidity and mortality in critically burned patients. Renal inflammation plays a vital role in the progression of early AKI, acting as a therapeutic target. Astaxanthin (ATX) is a strong antioxidant widely distributed in marine organisms that exerts many biological effects in trauma and disease. ATX is also suggested to have anti-inflammatory activity. Hence, we attempted to explore the role of ATX in protecting against early postburn AKI via its anti-inflammatory effects and the related mechanisms. A severely burned model was established for histological and biochemical assessments based on adult male rats. We found that oxidative stress-induced tissue inflammation participated in the development of early AKI after burn injury and that the MyD88-dependent TLR4/NF-κB pathway was activated to regulate renal inflammation. The TLR4 and NF-κB inhibitors TAK242 and PDTC showed similar effects in attenuating burn-induced renal inflammation and early AKI. Upon ATX treatment, the release of inflammatory mediators in the kidneys was downregulated, while the TLR4/MyD88/NF-κB axis was inhibited in a dose-related manner. TAK242 and PDTC could enhance the anti-inflammatory effect of high-dose ATX, whereas lipopolysaccharide (LPS) reversed its action. Furthermore, the expression of heme oxygenase (HO)-1 was upregulated by ATX in a dose-related manner. Collectively, the above data suggest that ATX protects against renal inflammation in a dose-related manner by regulating the TLR4/MyD88/NF-κB axis and HO-1 and ultimately prevents early AKI following severe burns.

Pouteria sapota (Red Mamey Fruit): Chemistry and Biological Activity of Carotenoids

BACKGROUND

Red mamey fruit known as P. sapota, comes from trees found in Mesoamerica and Asia. This fruit is considered a nutraceutical food due to it's a food and has multiple beneficial health including anti-amyloidogenic activity and potential anti-tumorigenic property. Red mamey fruit contain a variety of carotenoids including novel ketocarotenoids such as sapotexanthin and cryptocapsin. A ketocarotenoid is a chemical compound with a carbonyl group present in the β-ring or in the double bond chain of a carotenoid. In red mamey, the 3'-deoxy-k-end group in sapotexanthin has proved to be an important pro-vitamin A source, which is essential for maintaining a healthy vision and cognitive processes.

OBJECTIVE

Summarize the chemistry and biological activity of the studied carotenoids present in this fruit until now.

METHOD

An exhaustive extraction is the most usual methodology to isolate and thoroughly characterize the carotenoids present in this fruit. High performance liquid chromatography is used to determine the profile of total carotenoid and its purity. Atmospheric pressure chemical ionization is used to determine the molecular weight of carotenoid. Nuclear magnetic resonance is used to determine the structure of carotenoids.

RESULT

For each 100 g of fresh weight, 0.12 mg of total carotenoid from this fruit can be obtained. Out of the more than 47 reported carotenoids in red mamey, only 34 have a detailed characterization.

CONCLUSION

it is important to continue studying the chemical composition and biological activity of this unique tropical fruit with commercial and nutritional value.

Astaxanthin alleviates pathological brain aging through the upregulation of hippocampal synaptic proteins

Oxidative stress is currently considered to be the main cause of brain aging. Astaxanthin can improve oxidative stress under multiple pathological conditions. It is therefore hypothesized that astaxanthin might have therapeutic effects on brain aging. To validate this hypothesis and investigate the underlying mechanisms, a mouse model of brain aging was established by injecting amyloid beta (Aβ)25–35 (5 μM, 3 μL/injection, six injections given every other day) into the right lateral ventricle. After 3 days of Aβ_25–35 injections, the mouse models were intragastrically administered astaxanthin (0.1 mL/d, 10 mg/kg) for 30 successive days. Astaxanthin greatly reduced the latency to find the platform in the Morris water maze, increased the number of crossings of the target platform, and increased the expression of brain-derived neurotrophic factor, synaptophysin, sirtuin 1, and peroxisome proliferator-activated receptor-γ coactivator 1α. Intraperitoneal injection of the sirtuin 1 inhibitor nicotinamide (500 μM/d) for 7 successive days after astaxanthin intervention inhibited these phenomena. These findings suggest that astaxanthin can regulate the expression of synaptic proteins in mouse hippocampus through the sirtuin 1/peroxisome proliferator-activated receptor-γ coactivator 1α signaling pathway, which leads to improvements in the learning, cognitive, and memory abilities of mice. The study was approved by the Animal Ethics Committee, China Medical University, China (approval No. CMU2019294) on January 15, 2019.

Improved Anti-Inflammatory Effects of Liposomal Astaxanthin on a Phthalic Anhydride-Induced Atopic Dermatitis Model

Previously, we found that astaxanthin (AST) elicited an anti-inflammatory response in an experimental atopic dermatitis (AD) model. However, the use of AST was limited because of low bioavailability and solubility. We hypothesized that liposome formulation of AST could improve this. In this study, we compared the anti-inflammatory and anti-dermatotic effects of liposomal AST (L-AST) and free AST. We evaluated the effect of L-AST on a phthalic anhydride (PA)-induced animal model of AD by analyzing morphological and histopathological changes. We measured the mRNA levels of AD-related cytokines in skin tissue and immunoglobulin E concentrations in the serum. Oxidative stress and transcriptional activities of signal transducer and activator of transcription 3 (STAT3) and nuclear factor (NF)-κB were analyzed via western blotting and enzyme-linked immunosorbent assay. PA-induced dermatitis severity, epidermal thickening, and infiltration of mast cells in skin tissues were ameliorated by L-AST treatment. L-AST suppressed AD-related inflammatory mediators and the inflammation markers, inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX)-2 in PA-induced skin conditions. Oxidative stress and expression of antioxidant proteins, glutathione peroxidase-1 (GPx-1) and heme oxygenase-1 (HO-1), were recovered by L-AST treatment in skin tissues from PA-induced mice. L-AST treatment reduced transcriptional activity of STAT3 and NF-κB in PA-induced skin tissues. Our results indicate that L-AST could be more effective than free AST for AD therapy.

Anti-inflammatory effects of astaxanthin against fungal keratitis

AIM

To characterize effect of astaxanthin (ASX) in Aspergillus fumigatus (A. fumigatus) induced keratitis in mouse model.

METHODS

In vivo, fungal keratitis mouse model was established in C57BL/6 mice using A. fumigatus, followed by ASX or dimethyl sulfoxide (DMSO) treatment. Clinical responses were evaluated by clinical score and myeloperoxidase (MPO) assay. Inflammatory cytokines were assessed by reverse-transcription polymerase chain reaction (RT-PCR), Western blot, immunofluorescence, and enzyme-linked immuno sorbent assay (ELISA).

RESULTS

In animal model, ASX improved corneal transparency and clinical response, suppressed the expression of inflammatory cytokine like IL-1β, TNF-α, and HMGB-1. Neutrophil levels have been shown to decrease in ASX-treated cornea by immunofluorescence and MPO. TLR2 and TLR4 levels were lower in ASX-treated group than DMSO-treated.

CONCLUSION

ASX can suppress inflammatory response and reduce inflammatory cytokine production in mice model with A. fumigatus keratitis.

Attenuation of Nrf2/Keap1/ARE in Alzheimer's Disease by Plant Secondary Metabolites: A Mechanistic Review

Alzheimer’s disease (AD) is a progressive neuronal/cognitional dysfunction, leading to disability and death. Despite advances in revealing the pathophysiological mechanisms behind AD, no effective treatment has yet been provided. It urges the need for finding novel multi-target agents in combating the complex dysregulated mechanisms in AD. Amongst the dysregulated pathophysiological pathways in AD, oxidative stress seems to play a critical role in the pathogenesis progression of AD, with a dominant role of nuclear factor erythroid 2-related factor 2 (Nrf2)/Kelch-like ECH-associated protein-1 (Keap1)/antioxidant responsive elements (ARE) pathway. In the present study, a comprehensive review was conducted using the existing electronic databases, including PubMed, Medline, Web of Science, and Scopus, as well as related articles in the field. Nrf2/Keap1/ARE has shown to be the upstream orchestrate of oxidative pathways, which also ameliorates various inflammatory and apoptotic pathways. So, developing multi-target agents with higher efficacy and lower side effects could pave the road in the prevention/management of AD. The plant kingdom is now a great source of natural secondary metabolites in targeting Nrf2/Keap1/ARE. Among natural entities, phenolic compounds, alkaloids, terpene/terpenoids, carotenoids, sulfur-compounds, as well as some other miscellaneous plant-derived compounds have shown promising future accordingly. Prevailing evidence has shown that activating Nrf2/ARE and downstream antioxidant enzymes, as well as inhibiting Keap1 could play hopeful roles in overcoming AD. The current review highlights the neuroprotective effects of plant secondary metabolites through targeting Nrf2/Keap1/ARE and downstream interconnected mediators in combating AD.

Two-dimensional liquid chromatography analysis of all-trans-, 9-cis-, and 13-cis-astaxanthin in raw extracts from Phaffia rhodozyma

An effective two-dimensional liquid chromatography method has been established for the analysis of all-trans-astaxanthin and its geometric isomers from Phaffia rhodozyma employing a C18 column at the first dimension and a C30 column in the second dimension, connected by a 10-port valve using the photo-diode array detector. The regression equation of astaxanthin calibration curve was established, and the precision and accuracy values were found to be in the range of 0.32-1.14% and 98.21-106.13%, respectively. By using two-dimensional liquid chromatography, it was found that day light, ultrasonic treatment, and heat treatment have significant influence on the content of all-trans-astaxanthin in the extract from P. rhodozyma due to the transformation of all-trans-astaxanthin to cis-astaxanthin. The day light and ultrasonic treatments more likely transform all-trans-astaxanthin to 9-cis-astaxanthin, and the thermal treatment transforms all-trans-astaxanthin to 13-cis-astaxanthin. These results indicate that the two-dimensional liquid chromatography method can facilitate monitoring astaxanthin isomerization in the raw extract from P. rhodozyma. In addition, the study will provide a general reference for monitoring other medicals and bioactive chemicals with geometric isomers.

Marine Biocompounds for Neuroprotection-A Review

While terrestrial organisms are the primary source of natural products, recent years have witnessed a considerable shift towards marine-sourced biocompounds. They have achieved a great scientific interest due to the plethora of compounds with structural and chemical properties generally not found in terrestrial products, exhibiting significant bioactivity ten times higher than terrestrial-sourced molecules. In addition to the antioxidant, anti-thrombotic, anti-coagulant, anti-inflammatory, anti-proliferative, anti-hypertensive, anti-diabetic, and cardio-protection properties, marine-sourced biocompounds have been investigated for their neuroprotective potential. Thus, this review aims to describe the recent findings regarding the neuroprotective effects of the significant marine-sourced biocompounds.

Pyropia yezoensis Extract Suppresses IFN-Gamma- and TNF-Alpha-Induced Proinflammatory Chemokine Production in HaCaT Cells via the Down-Regulation of NF-κB

Pyropia yezoensis, a red alga, is popular and harvested a lot in East Asia and is famous for its medicinal properties attributable to its bioactive compounds including amino acids (porphyra-334 and shinorine, etc.), polysaccharides, phytosterols, and pigments, but its anti-inflammatory effect and mechanism of anti-atopic dermatitis (AD) have not been elucidated. In this study, we investigate the anti-AD effect of P. yezoensis extract (PYE) on mRNA and protein levels of the pro-inflammatory chemokines, thymus, and activation-regulated chemokine (TARC/CCL17) and macrophage-derived chemokine (MDC/CCL22), in human HaCaT keratinocyte cells treated to interferon (IFN)-γ or tumor necrosis factor (TNF)-α (10 ng/mL each). The effect of the PYE on extracellular signal-regulated kinase (ERK) and other mitogen-activated protein kinases (MAPKs) was related to its suppression of TARC and MDC production by blocking NF-κB activation in HaCaT cells. Furthermore, astaxanthin and xanthophyll from P. yezoensis were identified as anti-AD candidate compounds. These results suggest that the PYE may improve AD and contained two carotenoids by regulating pro-inflammatory chemokines.

Dietary Supplementation of the Antioxidant Curcumin Halts Systemic LPS-Induced Neuroinflammation-Associated Neurodegeneration and Memory/Synaptic Impairment via the JNK/NF-κB/Akt Signaling Pathway in Adult Rats

Curcumin is a natural polyphenolic compound widely known to have antioxidant, anti-inflammatory, and antiapoptotic properties. In the present study, we explored the neuroprotective effect of curcumin against lipopolysaccharide- (LPS-) induced reactive oxygen species- (ROS-) mediated neuroinflammation, neurodegeneration, and memory deficits in the adult rat hippocampus via regulation of the JNK/NF-κB/Akt signaling pathway. Adult rats were treated intraperitoneally with LPS at a dose of 250 μg/kg for 7 days and curcumin at a dose of 300 mg/kg for 14 days. After 14 days, the rats were sacrificed, and western blotting and ROS and lipid peroxidation assays were performed. For immunohistochemistry and confocal microscopy, the rats were perfused transcardially with 4% paraformaldehyde. In order to verify the JNK-dependent neuroprotective effect of curcumin and to confirm the in vivo results, HT-22 neuronal and BV2 microglial cells were exposed to LPS at a dose of 1 μg/ml, curcumin 100 μg/ml, and SP600125 (a specific JNK inhibitor) 20 μM. Our immunohistochemical, immunofluorescence, and biochemical results revealed that curcumin inhibited LPS-induced oxidative stress by reducing malondialdehyde and 2,7-dichlorofluorescein levels and ameliorating neuroinflammation and neuronal cell death via regulation of the JNK/NF-κB/Akt signaling pathway both in vivo (adult rat hippocampus) and in vitro (HT-22/BV2 cell lines). Moreover, curcumin markedly improved LPS-induced memory impairment in the Morris water maze and Y-maze tasks. Taken together, our results suggest that curcumin may be a potential preventive and therapeutic candidate for LPS-induced ROS-mediated neurotoxicity and memory deficits in an adult rat model.

Bee Venom Soluble Phospholipase A2 Exerts Neuroprotective Effects in a Lipopolysaccharide-Induced Mouse Model of Alzheimer's Disease via Inhibition of Nuclear Factor-Kappa B

Neuroinflammation is important in the pathogenesis and development of Alzheimer's disease (AD). In the AD brain, microglial activation and upregulation of pro-inflammatory mediators both induce amyloid beta (Aβ) accumulation. Regulatory T cells (Tregs) and nuclear factor-kappa B (NF-κB) signaling have been implicated in AD development through their effects on neuroinflammation and microglial activation. The bee venom soluble phospholipase A2 (bv-sPLA2) enzyme is known to exert anti-inflammatory and anti-immune effects. Here, we investigated the inhibitory effects of bv-sPLA2 on memory deficiency in a lipopolysaccharide (LPS)-induced mouse model of AD. We examined whether bv-sPLA2 (0.02, 0.2, and 2 mg/kg by i.p. injection three times for 1 week) could inhibit neuroinflammation and memory impairment in LPS-treated mice (250 μg/kg by i.p. injection daily for 1 week). We also assessed the effects of bv-sPLA2 administration (0.01, 0.1, and 1 μg/ml) on LPS (1 μg/ml)-treated microglial BV-2 cells. In the LPS-injected mouse brain, sPLA2 treatment rescued memory dysfunction and decreased Aβ levels, through the downregulation of amyloidogenic proteins, and decreased the expression of inflammatory proteins and pro-inflammatory cytokines. Moreover, the LPS-mediated increase in inflammatory protein expression was attenuated bv-sPLA2 treatment in BV-2 cells. Treatment with bv-sPLA2 also downregulated signaling by NF-κB, which is considered to be an important factor in the regulation of neuroinflammatory and amyloidogenic responses, both in vivo and in vitro. Additionally, co-treatment with NF-κB (5 μM) and bv-sPLA2 (0.1 μg/ml) exerted more marked anti-inflammatory effects, compared to bv-sPLA2 treatment alone. These results indicate that bv-sPLA2 inhibits LPS-induced neuroinflammation and amyloidogenesis via inhibition of NF-κB.

Antioxidant Therapies for Neuroprotection-A Review

Although moderate concentrations of reactive oxygen species (ROS) and reactive nitrogen species (RNS) are crucial for various physiological processes within the human body, their overproduction leads to oxidative stress, defined as the imbalance between the production and accumulation of ROS and the ability of the body to neutralize and eliminate them. In the brain, oxidative stress exhibits significant effects, due to its increased metabolical activity and limited cellular regeneration. Thus, oxidative stress is a major factor in the progressive loss of neurons structures and functions, leading to the development of severe neurodegenerative disorders. In this context, recent years have witnessed tremendous advancements in the field of antioxidant therapies, with a special emphasis for neuroprotection. The aim of this paper is to provide an overview of the oxidative stress and antioxidant defense mechanisms and to present the most recent studies on antioxidant therapies for neuroprotection.