Lutein Exerts Antioxidant and Anti-Inflammatory Effects and Influences Iron Utilization of BV-2 Microglia

Exploring anti-inflammatory and antioxidant-related quality markers of Artemisia absinthium L. based on spectrum-effect relationship

INTRODUCTION

Artemisia absinthium L. is a well-known medicinal, aromatic, and edible plant with important medicinal and economic properties and a long history of use in treating liver inflammation and other diseases; however, there has been insufficient progress in quality control.

OBJECTIVE

This study aimed to investigate the quality markers for the anti-inflammatory and antioxidant activities of A. absinthium based on spectrum-effect relationship analysis.

MATERIALS AND METHODS

Eighteen batches of A. absinthium from different origins were used. Chemical fingerprints were obtained by ultra-performance liquid chromatography (UPLC). The chemical compositions were identified by quadrupole-Orbitrap high-resolution mass spectrometry. Anti-inflammatory activity was assessed by inhibition of cyclooxygenase-2 and 15-lipoxygenase in vitro and inhibition of nitric oxide release in lipopolysaccharide-induced BV-2 cells. Antioxidant activity was assessed by DPPH and ABTS radical scavenging assays. The relationship between bioactivity and chemical fingerprints was then analyzed using chemometrics including gray relational analysis, bivariate correlation analysis, and orthogonal partial least squares analysis.

RESULTS

Different batches of A. absinthium extracts possessed significant anti-inflammatory and antioxidant activities to varying degrees. Eighty compounds were identified from A. absinthium, and 12 main common peaks were obtained from the UPLC fingerprints. P3 (chlorogenic acid), P5 (isochlorogenic acid A), and P6 (isochlorogenic acid C) were screened as the most promising active compounds by correlation analysis and further validated for their remarkable anti-inflammatory effects.

CONCLUSION

This is the first study to screen the quality markers of A. absinthium by establishing the spectrum-effect relationship, which can provide a reference for the development of quality standards and further research on A. absinthium.

P2X7 receptor: A receptor closely linked with sepsis-associated encephalopathy

Sepsis is defined as a dysregulated host response to infection resulting in life-threatening organ dysfunction. Sepsis-associated encephalopathy (SAE) is the main manifestation of sepsis. Inflammation, peroxidation stress injury, and apoptosis are the main factors involved in the pathogenesis of SAE. A growing body of evidence has proved that P2X7 receptor (P2X7R), a cationic channel receptor that is widely distributed in the body, plays a major role in the occurrence and development of inflammatory injury. Therefore, this review mainly describes the activation of P2X7R in sepsis, which leads to the recruitment of inflammatory cells to the cerebral vasculature, the destruction of the blood-brain barrier, the activation of microglial cells in the brain, the apoptosis of brain cells, and other damage processes. This review also illustrates the potential therapeutic value of P2X7R inhibition in SAE.

Lutein Production and Extraction from Microalgae: Recent Insights and Bioactive Potential

Microalgae have been reported to be excellent producers of bioactive molecules. Lutein is a pigment reported to have various beneficial effects for humans, and especially for eye well-being. In the current review, we summarize various methods that have been developed to optimize its extraction and bioactivities reported for human health. Several protective effects have been reported for lutein, including antioxidant, anticancer, anti-inflammatory, and cardioprotective activity. This review also reports attempts to increase lutein production by microalgae by changing culturing parameters or by using pilot-scale systems. Genetic engineering lutein production is also discussed. Considering the increasing aging of the worldwide population will create an increased need for lutein, a viable economic and eco-sustainable method to produce lutein is needed to face this market demand.

Polyunsaturated Lipids in the Light-Exposed and Prooxidant Retinal Environment

The retina is an oxidative stress-prone tissue due to high content of polyunsaturated lipids, exposure to visible light stimuli in the 400–480 nm range, and high oxygen availability provided by choroidal capillaries to support oxidative metabolism. Indeed, lipids’ peroxidation and their conversion into reactive species promoting inflammation have been reported and connected to retinal degenerations. Here, we review recent evidence showing how retinal polyunsaturated lipids, in addition to oxidative stress and damage, may counteract the inflammatory response triggered by blue light-activated carotenoid derivatives, enabling long-term retina operation despite its prooxidant environment. These two aspects of retinal polyunsaturated lipids require tight control over their synthesis to avoid overcoming their protective actions by an increase in lipid peroxidation due to oxidative stress. We review emerging evidence on different transcriptional control mechanisms operating in retinal cells to modulate polyunsaturated lipid synthesis over the life span, from the immature to the ageing retina. Finally, we discuss the antioxidant role of food nutrients such as xanthophylls and carotenoids that have been shown to empower retinal cells’ antioxidant responses and counteract the adverse impact of prooxidant stimuli on sight.

Lutein Isomers: Preparation, Separation, Structure Elucidation, and Occurrence in 20 Medicinal Plants

Lutein and its cis-isomers occur in a lot of plants, including a variety of flowers. In this study, lutein isomers were produced via iodine-catalyzed isomerization, and four cis-isomers (9Z-, 9'Z-, 13Z-, and 13Z') were isolated by means of column chromatography and semipreparative HPLC. The structures of the 9'Z- and 13'Z-isomers were elucidated via NMR measurements. These compounds were used as standards for the HPLC-DAD-MS determination of the carotenoid composition of the flowers of 20 plant species, in which lutein and its geometrical isomers are the main components. The flowers showed great variation in their cis- and trans-lutein content, and also in the presence or absence of other carotenoids, such as violaxanthin, neoxanthin, β-cryptoxanthin, and β-carotene. Some of the investigated flowers were found to be rich sources of lutein without zeaxanthin.

Lutein Decreases Inflammation and Oxidative Stress and Prevents Iron Accumulation and Lipid Peroxidation at Glutamate-Induced Neurotoxicity

The xanthophyll carotenoid lutein has been widely used as supplementation due to its protective effects in light-induced oxidative stress. Its antioxidant and anti-inflammatory features suggest that it has a neuroprotective role as well. Glutamate is a major excitatory neurotransmitter in the central nervous system (CNS), which plays a key role in regulating brain function. Excess accumulation of intracellular glutamate accelerates an increase in the concentration of reactive oxygen species (ROS) in neurons leading to glutamate neurotoxicity. In this study, we focused on the effects of glutamate on SH-SY5Y neuroblastoma cells to identify the possible alterations in oxidative stress, inflammation, and iron metabolism that affect the neurological function itself and in the presence of antioxidant lutein. First, ROS measurements were performed, and then catalase (CAT) and Superoxide Dismutase (SOD) enzyme activity were determined by enzyme activity assay kits. The ELISA technique was used to detect proinflammatory TNFα, IL-6, and IL-8 cytokine secretions. Alterations in iron uptake, storage, and release were followed by gene expression measurements and Western blotting. Total iron level detections were performed by a ferrozine-based iron detection method, and a heme assay kit was used for heme measurements. The gene expression toward lipid-peroxidation was determined by RT-PCR. Our results show glutamate changes ROS, inflammation, and antioxidant enzyme activity, modulate iron accumulation, and may initiate lipid peroxidation in SH-SY5Y cells. Meanwhile, lutein attenuates the glutamate-induced effects on ROS, inflammation, iron metabolism, and lipid peroxidation. According to our findings, lutein could be a beneficial, supportive treatment in neurodegenerative disorders.

The Role of Microglia in Alzheimer’s Disease From the Perspective of Immune Inflammation and Iron Metabolism

Alzheimer’s disease (AD), the most common type of senile dementia, includes the complex pathogenesis of abnormal deposition of amyloid beta-protein (Aβ), phosphorylated tau (p-tau) and neuroimmune inflammatory. The neurodegenerative process of AD triggers microglial activation, and the overactivation of microglia produces a large number of neuroimmune inflammatory factors. Microglia dysfunction can lead to disturbances in iron metabolism and enhance iron-induced neuronal degeneration in AD, while elevated iron levels in brain areas affect microglia phenotype and function. In this manuscript, we firstly discuss the role of microglia in AD and then introduce the role of microglia in the immune-inflammatory pathology of AD. Their role in AD iron homeostasis is emphasized. Recent studies on microglia and ferroptosis in AD are also reviewed. It will help readers better understand the role of microglia in iron metabolism in AD, and provides a basis for better regulation of iron metabolism disorders in AD and the discovery of new potential therapeutic targets for AD.

Orobanche crenata Forssk. Extract Affects Human Breast Cancer Cell MCF-7 Survival and Viral Replication

BACKGROUND

Breast cancer (BC) is the leading cause of death worldwide. The severity of BC strictly depends on the molecular subtype. The less aggressive hormone-positive subtype is treated with adjuvant endocrine therapy (AET), which causes both physical and psychological side effects. This condition strongly impacts the adherence and persistence of AET among oncologic patients. Moreover, viral infections also constitute a serious problem for public health. Despite their efficacy, antiviral agents present several therapeutic limits. Accordingly, in the present work, we investigated the antitumor and antiviral activities of Orobanche crenata Forssk. (O. crenata), a parasitic plant, endemic to the Mediterranean basin, traditionally known for its beneficial properties for human health.

METHODS

The MTT assay was carried out to evaluate the cytotoxic effect of O. crenata leaf extract (OCLE) on human breast cancer cells (MCF-7 and MDA-MB-231) and the primary HFF-1 cell line. The lactic dehydrogenase (LDH) assay was performed on MCF-7 cells to analyze necrotic cell death. The antioxidant effect of OCLE was evaluated by intracellular determination of the reactive oxygen species and thiol groups, by DPPH and ABTS assays. The antiviral activity of OCLE was determined against Poliovirus 1, Echovirus 9, Human respiratory syncytial virus, Adenovirus type 2 and type 5, Coxsackievirus B1 (CoxB1) and B3 (CoxB3), Herpes simplex type 1 (HSV-1) and type 2 (HSV-2), and β-Coronavirus by the plaque reduction assay.

RESULTS

The extract, after 24 h of incubation, did not affect MDA-MB-231 and HFF-1 cell viability. However, at the same time point, it showed a dose-dependent inhibitory effect on MCF-7 cells, with an increase in LDH release. OCLE exhibited free radical scavenging activity and significantly increased non-protein thiol levels in MCF-7 cells. OCLE effectively inhibited HSV-1, HSV-2, CoxB1, and CoxB3 replication.

CONCLUSIONS

The overall results showed an interesting inhibitory effect of OCLE on both MCF-7 cell survival and viral replication.

Effective inhibition of adipogenesis-mediated inflammation by a macular carotenoid, lutein in vitro

An absolute interlinks between inflammation and obesity with scarce investigations on the role of lutein in inflammation-induced obesity motivated us to explore the protective mechanism of lutein on adipogenesis-mediated inflammation in vitro by culturing RAW264.7 macrophages in adipocyte conditioned medium. The RAW264 macrophage cells were cultured with adipocyte-conditioned media, and the potency of lutein on the expression of adipocyte inflammation-associated protein markers (IL-1β, MCP-1, TNF-α, IL-6, NF-κB, and IKKα/β) were analyzed by western blotting. The data revealed that lutein effectively reduces the protein levels of major inflammatory markers such as NF-κB, IL-1β, MCP-1, and TNF-α in differentiated adipocytes. Interestingly, lutein hampered inflammation in the RAW264 cells that were cultured in adipocyte-conditioned media by lowering the protein expression of IL-1β, MCP-1, and TNF-α. The blockage of inflammation by lutein in both differentiated adipocytes, and adipogenesis-induced macrophages is associated with suppression of IKK α/β phosphorylation. These data suggest that lutein potentially alters adipocyte differentiation-mediated inflammation by regulating the NF-κB signaling pathway. Thus, lutein could be utilized as a potent nutraceutical agent in the management of obesity and associated inflammation. PRACTICAL APPLICATIONS: Lutein isolated from a dietary source exhibited an inhibitory effect in adipogenesis-induced inflammations. The findings of this study authenticate the diversified prospective of lutein in regulating obesity and other inflammation-related diseases. Thus, it is understood that continuous intake of lutein-rich food or dietary intervention of lutein may reduce the risk of developing obesity.

Comparison between Egg Intake versus Choline Supplementation on Gut Microbiota and Plasma Carotenoids in Subjects with Metabolic Syndrome

We previously demonstrated that intake of three eggs/d for 4 weeks increased plasma choline and decreased inflammation in subjects with metabolic syndrome (MetS). The purpose of the current study was to further explore the effects of phosphatidylcholine (PC) provided by eggs versus a choline bitartrate (CB) supplement on the gut microbiota, trimethylamine N-oxide (TMAO) formation, and plasma carotenoids lutein and zeaxanthin in MetS. This randomized, controlled crossover clinical trial included 23 subjects with MetS. Following a washout period of 2 weeks without consuming any choline-containing foods, subjects were randomly allocated to consume either three eggs/d or a CB supplement for 4 weeks (both diets had a choline equivalent of 400 mg/day). DNA was extracted from stool samples to sequence the 16S rRNA gene region for community analysis. Operational taxonomic units (OTUs) and the α-diversity of the community were determined using QIIME software. Plasma TMAO, methionine, betaine, and dimethylglycine (DMG) were quantified by stable isotope dilution liquid chromatography with tandem mass spectrometry. Plasma carotenoids, lutein, and zeaxanthin were measured using reversed-phase high-performance liquid chromatography. There were significant increases in plasma lutein and zeaxanthin after egg intake compared to the baseline or intake of CB supplement (p < 0.01). In contrast, TMAO was not different between treatments compared to the baseline (p > 0.05). Additionally, while diet intervention had no effects on microbiota diversity measures or relative taxa abundances, a correlation between bacterial biodiversity and HDL was observed. Following egg intake, the observed increases in plasma lutein and zeaxanthin may suggest additional protection against oxidative stress, a common condition in MetS.

Pharmacological Inhibition of Spermine Oxidase Suppresses Excitotoxicity Induced Neuroinflammation in Mouse Retina

Polyamine oxidation plays a major role in neurodegenerative diseases. Previous studies from our laboratory demonstrated that spermine oxidase (SMOX, a member of the polyamine oxidase family) inhibition using MDL 72527 reduced neurodegeneration in models of retinal excitotoxicity and diabetic retinopathy. However, the mechanisms behind the neuroprotection offered by SMOX inhibition are not completely studied. Utilizing the experimental model of retinal excitotoxicity, the present study determined the impact of SMOX blockade in retinal neuroinflammation. Our results demonstrated upregulation in the number of cells positive for Iba-1 (ionized calcium-binding adaptor molecule 1), CD (Cluster Differentiation) 68, and CD16/32 in excitotoxicity-induced retinas, while MDL 72527 treatment reduced these changes, along with increases in the number of cells positive for Arginase1 and CD206. When retinal excitotoxicity upregulated several pro-inflammatory genes, MDL 72527 treatment reduced many of them and increased anti-inflammatory genes. Furthermore, SMOX inhibition upregulated antioxidant signaling (indicated by elevated Nrf2 and HO-1 levels) and reduced protein-conjugated acrolein in excitotoxic retinas. In vitro studies using C8-B4 cells showed changes in cellular morphology and increased reactive oxygen species formation in response to acrolein (a product of SMOX activity) treatment. Overall, our findings indicate that the inhibition SMOX pathway reduced neuroinflammation and upregulated antioxidant signaling in the retina.

Identifying Potential Antioxidant Properties from the Viscera of Sea Snails (Turbo cornutus)

Turbo cornutus, the horned turban sea snail, is found along the intertidal and basaltic shorelines of Jeju Island, Korea. T. cornutus feeds on seaweeds (e.g., Undaria sp., and Ecklonia sp.) composed of diverse antioxidants. This study identified potential antioxidant properties from T. cornutus viscera tissues. Diverse extracts were evaluated for their hydrogen peroxide (H₂O₂) scavenging activities. T. cornutus viscera protamex-assisted extracts (TVP) were purified by gel filtration chromatography (GFC), and potential antioxidant properties were analyzed for their amino acid sequences and its peroxidase inhibition effects by in silico molecular docking and in vitro analysis. According to the results, T. cornutus viscera tissues are composed of many protein contents with each over 50%. Among the extracts, TVP possessed the highest H₂O₂ scavenging activity. In addition, TVP-GFC-3 significantly decreased intracellular reactive oxygen species (ROS) levels and increased cell viability in H₂O₂-treated HepG2 cells without cytotoxicity. TVP-GFC-3 comprises nine low molecular bioactive peptides (ELR, VGPQ, TDY, ALPHA, PAH, VDY, WSDK, VFSP, and FAPQY). Notably, the peptides dock to the active site of the myeloperoxidase (MPO), especially TDY and FAPQY showed the MPO inhibition effects with IC₅₀ values of 646.0 ± 45.0 µM and 57.1 ± 17.7 µM, respectively. Altogether, our findings demonstrated that T. cornutus viscera have potential antioxidant properties that can be used as high value-added ingredients.

Association between Dietary Lutein/Zeaxanthin Intake and Metabolic Syndrome among US Females: An Analysis of National Health and Examination Surveys 2015-2018

The prevalence of metabolic syndrome (MetS) is greater among US females than males, mainly due to higher risks of dyslipidemia and hyperglycemia. Lutein and zeaxanthin (L/Z) are carotenoids that can alter the composition of lipoproteins, which may affect components of MetS. However, little is known about the association between L/Z intake and MetS, especially in females. The purpose of this study was to explore the relation between dietary L/Z or dietary plus supplemental L/Z intakes and MetS in women (n = 630), aged 20-50 y, participating in the NHANES 2015-2018. Compared with the lowest quartile, women in the highest quartile of dietary L/Z intake had significantly lower risk of MetS after adjusting for confounders (OR = 0.46; 95% CI: 0.21, 0.98). No significant relation was noted between dietary plus supplemental L/Z intake and MetS. Future cohort studies should investigate the effects of L/Z on MetS development in women.

Antihyperlipidemic and Antioxidant Capacities, Nutritional Analysis and UHPLC-PDA-MS Characterization of Cocona Fruits (Solanum sessiliflorum Dunal) from the Peruvian Amazon

Cocona fruits are a popular food and medicinal fruit used mainly in the Amazon and several countries of South America for the preparation of several food products such as drinks, jams and milk shakes. In this study five ecotypes of cocona native to Peru have been studied regarding their nutritional and antioxidants values plus antihyperlipidemic activities. Seventy bioactive compounds have been detected in Peruvian cocona ecotypes including several phenolic acids, aminoacids and flavonoids; of those six were spermidines, (peaks 1, 2, 25, 26, 38 and 39), thirteen were aminoacids, (peaks 3-9, 11-13, 16, 17, 22-24), eighteen flavonoids (peaks 28, 30-32 45,46, 48-53 56, 57, 61 and 64-66), twelve were phenolics (peaks 19, 21, 27, 29, 34, 35, 36, 42, 43, 44, 54, and 59), two carotenoids, (peak 62 and 63), eight were lipid derivatives (peaks 37, 55, 58, 60 and 67-70), one sugar (peak 47), four terpenes (peaks 33, 40, 41 and 47), two amides, (peaks 10 and 18), one aldehyde, (peak 15), and three saturated organic acids, (peaks 4, 5 and 20). Hypercholesterolemic rats administered with pulp of the ecotypes CTR and SRN9 showed the lowest cholesterol and triglyceride levels after treatment (126.74 ± 6.63; 102.11 ± 9.47; 58.16 ± 6.64; 61.05 ± 4.00 mg/dL, for cholesterol, triglycerides, high-density lipoprotein and low-density lipoprotein respectively, for the group treated with SRN9 pulp, and 130.09 ± 8.55; 108.51 ± 10.04; 57.30 ± 5.72; and 65.41 ± 7.68 mg/dL, for cholesterol, triglycerides, HDL and LDL lipoproteins respectively for the group treated with CTR pulp). The ecotypes proved to be good sources of natural antioxidants and their consumption represent an alternative for the prevention of atherosclerosis.

Early Pediatric Benefit of Lutein for Maturing Eyes and Brain-An Overview

Lutein is a dietary carotenoid preferentially accumulated in the eye and the brain in early life and throughout the life span. Lutein accumulation in areas of high metabolism and oxidative stress such as the eye and the brain suggest a unique role of this ingredient during the development and maturation of these organs of common embryological origin. Lutein is naturally provided to the developing baby via the cord blood, breast milk and then infant diet. The presence of this carotenoid depends on fruit and vegetable intakes and its bioavailability is higher in breastmilk. This paper aims to review the anatomical development of the eye and the brain, explore the presence and selective deposition of lutein in these organs during pregnancy and infancy and, based on its functional characteristics, present the latest available research on the beneficial role of lutein in the pediatric population. The potential effects of lutein in ameliorating conditions associated with increase oxidative stress such as in prematurity will be also addressed. Since consumption of lutein rich foods falls short of government guidelines and in most region of the world infant formulas lack this bioactive, dietary recommendations for pregnant and breastfeeding women and their child can help to bridge the gap.

In silico studies of selected xanthophylls as potential candidates against SARS-CoV-2 targeting main protease (Mpro) and papain-like protease (PLpro)

Introduction: The main protease (Mpro) and the papain-like protease (PLpro) are essential for the replication of SARS-CoV-2. Both proteases can be targets for drugs acting against SARS-CoV-2.

Objective: This paper aims to investigate the in silico activity of nine xanthophylls as inhibitors of Mpro and PLpro.

Methods: The structures of Mpro (PDB-ID: 6LU7) and PLpro (PDB-ID: 6W9C) were obtained from RCSB Protein Data Bank and developed with BIOVIA Discovery Studio. Active sites of proteins were performed using CASTp. For docking the PyRx was used. Pharmacokinetic parameters of ADMET were evaluated using SwissADME and pkCSM.

Results: β-cryptoxanthin exhibited the highest binding energy: –7.4 kcal/mol in the active site of Mpro. In PLpro active site, the highest binding energy had canthaxanthin of –9.4 kcal/mol, astaxanthin –9.3 kcal/mol, flavoxanthin –9.2 kcal/mol and violaxanthin –9.2 kcal/mol. ADMET studies presented lower toxicity of xanthophylls in comparison to ritonavir and ivermectin.

Conclusion: Our findings suggest that xanthophylls can be used as potential inhibitors against SARS-CoV-2 main protease and papain-like protease.