Antioxidant properties of lutein contribute to the protection against lipopolysaccharide-induced uveitis in mice

Polyvinylpyrrolidone-curcumin nanoparticles with immune regulatory and metabolism regulatory effects for the treatment of experimental autoimmune uveitis

Uveitis comprises a cluster of intraocular inflammatory disorders characterized by uncontrolled autoimmune responses and excessive oxidative stress leading to vision loss worldwide. In the present study, curcumin (CUR) was conjugated with polyvinylpyrrolidone (PVP) to form PVP-CUR nanoparticles with significantly elevated solubility and outstanding multiple radical scavenging abilities. In vitro studies revealed that PVP-CUR nanoparticles markedly mitigated oxidative stress and reduced apoptosis in a H2O2-induced human retinal pigment epithelial cell line (ARPE-19) and promoted phenotypic polarization from M1 to M2 in an LPS-induced human microglial cell line (HMC3). Further in vivo studies demonstrated the prominent therapeutic effects of PVP-CUR nanoparticles on experimental autoimmune uveitis (EAU), which relieved clinical and pathological progression, improved perfusion and tomographic manifestations of retinal vessels, and reduced blood-retinal barrier (BRB) leakage; these effects may be mediated by mitigating oxidative stress and attenuating macrophage/microglia-elicited inflammation. Notably, treatment with PVP-CUR nanoparticles was shown to regulate metabolite alterations in EAU rats, providing novel insights into the underlying mechanisms involved. Additionally, the PVP-CUR nanoparticles showed great biocompatibility in vivo. In summary, our study revealed that PVP-CUR nanoparticles may serve as effective and safe nanodrugs for treating uveitis and other oxidative stress- and inflammation-related diseases.

A mechanistic review on growing multiple therapeutic applications of lutein and its global market research

Lutein is a naturally occurring carotenoid synthesized by plants and algae that has a beneficial effect on several biological processes and associated ailments. Its immediate application is in ophthalmology, where it significantly lowers the incidences of age-related macular degeneration (AMD). It also has anti-inflammatory action, treatment of diabetic retinopathy, and cataracts, and enhancement of visual contrast. To critically assess lutein biosynthesis, therapeutic applicability, and market research literature. We have discussed its theoretical frameworks, experimental evidence, limitations, as well as clinical trial results, and future research prospects. The literature for this review article was mined and compiled by collecting and analyzing articles from several databases, including ScienceDirect, Google Scholar, PubMed, Wiley Online Library, Patentscope, and ClinicalTrials.gov published until March 30, 2022. Patent publications were identified using the search terms like IC:(C07C67/56) AND EN_AB:(lutein) OR EN_TI:(lutein) OR EN_AB:(extraction) OR EN_TI:(process). According to the literature, lutein is an essential nutrient given that it cannot be synthesized in the human body and acts as an antioxidant, affecting AMD, diabetic retinopathy, Rheumatic diseases, inflammation, and cancer. Due to inadequate production and laborious extraction, lutein is expensive despite its high demand and applicability. Market research predicts a 6.3% compound annual growth rate for lutein by 2032. Optimizing lutein extraction for high yield and purity is necessary. Lutein has proven applicability in various ailments as well as cosmetics that can be developed as a candidate drug for various diseases discussed in the review.

Lutein Encapsulated in PLGA–Phospholipid Nano-Carrier Effectively Mitigates Cytokines by Inhibiting Tumor Necrosis Factor TNF-α and Nuclear Factor NF-κB in Mice Retina

Lutein, a photo- and thermo-labile macular pigment, prevents the retina from suffering ocular inflammation with its antioxidant and anti-inflammatory activity. However, its biological activity is poor due to poor solubility and bioavailability. Therefore, we developed a PLGA NCs (+PL), (poly (lactic-co-glycolic acid) nanocarrier with phospholipid) to improve the biological availability and bioefficacy of lutein in the retina of lipopolysaccharide (LPS)-induced lutein-devoid (LD) mice. The effect of lutein-loaded NCs with/without PL was studied in comparison with micellar lutein. The induction of inflammation by LPS significantly increased the production of nitrites in the LPS-induced group, revealing higher levels of nitric oxide (NO) in the serum (760%) and retina (891%) compared to the control group. Malondialdehyde (MDA) levels in the serum (93%) and retina (205%) of the LPS-induced group were higher compared to the control group. LPS induction resulted in increased protein carbonyls in the serum (481%) and retina (487%) of the LPS group compared to the control group. Further, to conclude, lutein-PLGA NCs (+PL) effectively down-regulated inflammatory complications in the retina.

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.

Antiobesity drug-likeness properties and pancreatic lipase inhibition of a novel low molecular weight lutein oxidized product, LOP6

Elevated expression of peroxisome proliferator-activated receptor-gamma (PPAR-γ), a key regulator of adipogenesis, leads to lipid accumulation and obesity. Although orlistat is effective for obesity, flatus with discharge, faecal urgency, oily evacuation and other allied side effects limit its usage. Thus, natural product-based drug intervention is the future of research and development of novel treatment. We synthesized and characterized total lutein oxidized products (LOPs) by exposing lutein to direct sunlight with a solar intensity of 5.89 kW h m^-2 day^-1 and at 31 ± 2 °C for 1-10 days. Total LOPs were analyzed on C₁₈ and structural elucidation was carried on LCMS/MS-TOF. The pancreatic lipase inhibition kinetics was estimated. The binding effects of LOP6 (fragmented peak 6) on PPAR-γ, pancreatic lipase, pharmacokinetic properties and inhibition studies were analysed. Histological evaluation of liver and adipose tissues was performed to confirm the antiobesity effect of total LOPs. The yield of extracted lutein purified from shade-dried marigold flower petals was 6%. Total LOPs were formed on the 10th day upon exposure of lutein to direct sunlight. Total LOPs on the C₁₈ column fragmented into eight oxidized products (LOP1 to LOP8). The total LOPs showed significant inhibition of pancreatic lipase activity with an IC₅₀ of 1.6953 μg ml^-1, and K_m and V_max of 3.05 μg and 1.19 μg s^-1 respectively following mixed type of inhibition. The LOP6 [4-((1E,3E,5E)-3,7-dimethylocta-1,3,5,7-tetraen-1-yl)-3,5,5-trimethylcyclohex-3-enol] with an approximate molecular mass of 274.25 showed a binding energy of -5.40 kcal mol^-1 with a K_i of 109.43 μM for PPAR-γ and a docking score of -5.35 kcal mol^-1 with a K_i of 119.4 μM for pancreatic lipase. The IC₅₀ of LOP6 was 11.8420 μg ml^-1, and K_m and V_max were 2.519 μg and 1.294 μg s^-1. The pharmacokinetic properties such as solubility, permeability, bioavailability, and topological polar surface area when tested with LOP6 were significantly better than those of lutein alone. The histological examination of the liver and adipose tissue revealed that all three doses of total LOPs were effective in alleviating the ballooning and vesicular degeneration of hepatocytes and invasion of inflammatory cells in the adipose tissue. Total LOPs and LOP6 inhibited pancreatic lipase activity in vitro. LOP6 showed a better docking score for PPAR-γ and pancreatic lipase in comparison to orlistat. Histological data showed that the total LOPs exerted antiobesity activity. Thus, LOPs might provide a novel treatment approach for obesity.

Induction of lutein production in Scenedesmus obliquus under different culture conditions prior to its semipreparative isolation

Microalgae with their improved growth rates and accumulation of high-value-added products make their commercial production attractive. Among them, lutein, which is a carotenoid, plays a very important role due to its various applications in the food and pharmaceutical industry. Induction of its biosynthesis can be triggered by various stress conditions like light. In this study, three different light intensities (50,150 and 300 μmol photons/m2s) and aeration rates (1, 3, and 5 L/min) were utilized to induce the lutein biosynthesis and biomass productivity in Scenedesmus obliquus. Lutein was isolated by preparative chromatography using a semiprep C30 column (10 × 250 mm, 5μm) and its confirmation was made by LC-MS/MS. According to the results, Scenedesmus obliquus synthesized the maximum lutein (8.01 ± 0.1 mg/g) with biomass productivity of 1.698 g/L at 150 μmol photons/m2s light intensity using 3 L/min as aeration rate. To the best of the authors' knowledge, this was the first study that the lutein was isolated by preparative chromatography using semiprep C30 carotenoid column with a simple and rapid separation, which can be used as a reference methodology for the isolation of other carotenoids. Scenedesmus obliquus can be an important alternative source for commercial production of lutein, as it is indicated from the results of this study.

Gloeothece sp.-Exploiting a New Source of Antioxidant, Anti-Inflammatory, and Antitumor Agents

Bioactive lipidic compounds of microalgae, such as polyunsaturated fatty acids (PUFA) and carotenoids, can avoid or treat oxidation-associated conditions and diseases like inflammation or cancer. This study aimed to assess the bioactive potential of lipidic extracts obtained from Gloeothece sp.–using Generally Recognized as Safe (GRAS) solvents like ethanol, acetone, hexane:isopropanol (3:2) (HI) and ethyl lactate. The bioactive potential of extracts was assessed in terms of antioxidant (ABTS^•+, DPPH^•, ^•NO and O₂^•assays), anti-inflammatory (HRBC membrane stabilization and Cox-2 screening assay), and antitumor capacity (death by TUNEL, and anti-proliferative by BrdU incorporation assay in AGS cancer cells); while its composition was characterized in terms of carotenoids and fatty acids, by HPLC-DAD and GC-FID methods, respectively. Results revealed a chemopreventive potential of the HI extract owing to its ability to: (I) scavenge ^-NO^• radical (IC₅₀, 1258 ± 0.353 µg·mL⁻¹); (II) inhibit 50% of COX-2 expression at 130.2 ± 7.4 µg·mL⁻¹; (III) protect 61.6 ± 9.2% of lysosomes from heat damage, and (IV) induce AGS cell death by 4.2-fold and avoid its proliferation up to 40% in a concentration of 23.2 ± 1.9 µg·mL⁻¹. Hence, Gloeothece sp. extracts, namely HI, were revealed to have the potential to be used for nutraceutical purposes.

Development of Lutein-Containing Eye Drops for the Treatment of Dry Eye Syndrome

Dry eye syndrome (DES) is a common ophthalmological disease that decreases tear secretion and causes dryness, photophobia, pain, severe corneal rupture, and even blindness. Ocular and lacrimal gland inflammation is one of the pathological mechanisms underlying DES. Therefore, effective suppression of inflammation is a crucial strategy for the treatment of DES. Lutein, commonly found in healthy foods, has anti-inflammatory effects in corneal or retina-related cells and may be a potential therapy for DES. The addition of lutein to artificial tears (AT) as an eye-drop formulation for DES treatment in a mouse model was studied in the present work. Polyvinyl alcohol (PVA) was used as a thickener to increase the viscosity of eye drops to prolong drug retention on the ocular surface. A WST-8 assay in human corneal epithelial cells (HCE-2) showed that a concentration of <5 μM lutein (L5) and <1% PVA (P1) maintained the cell viability at 80%. A real-time PCR showed that the inflamed human corneal epithelial cells (HCECs) cocultured with L5P1 had downregulated expression of inflammatory genes such as IL-1β, IL-6, and TNF-α. In a benzalkonium chloride- (BAC) induced DES mouse model, AT/L5P1 could repair damaged corneas, elevate tear secretion, increase the number of goblet cells, and inhibit the production of inflammatory cytokines, such as IL-1β, IL-6, and TNF-α, in the cornea. In conclusion, we demonstrate that lutein/PVA as eye drops could prolong the drug ocular retention time and effectively to decrease inflammation in DES mice. Therefore, lutein, obtained from eye drops, has a potential therapeutic role for DES.

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.

Enzymatic Degradation of Gracilariopsis lemaneiformis Polysaccharide and the Antioxidant Activity of Its Degradation Products

Gracilariopsis lemaneiformis polysaccharides (GLP) were degraded using pectinase, glucoamylase, cellulase, xylanase, and β-dextranase into low-molecular-weight polysaccharides, namely, GPP, GGP, GCP, GXP, and GDP, respectively, and their antioxidant capacities were investigated. The degraded GLP showed higher antioxidant activities than natural GLP, and GDP exhibited the highest antioxidant activity. After the optimization of degradation conditions through single-factor and orthogonal optimization experiments, four polysaccharide fractions (GDP1, GDP2, GDP3, and GDP4) with high antioxidant abilities (hydroxyl radical scavenging activity, DPPH radical scavenging activity, reduction capacity, and total antioxidant capacity) were obtained. Their cytoprotective activities against H2O2-induced oxidative damage in human fetal lung fibroblast 1 (HFL1) cells were examined. Results suggested that GDP pretreatment can significantly improve cell viability, reduce reactive oxygen species and malonaldehyde levels, improve antioxidant enzyme activity and mitochondria membrane potential, and alleviate oxidative damage in HFL1 cells. Thus, the enzyme degradation of GLP with β-dextranase can significantly improve its antioxidant activity, and GDP might be a suitable source of natural antioxidants.

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

Lutein is a tetraterpene carotenoid, which has been reported as an important antioxidant and it is widely used as a supplement. Oxidative stress participates in many human diseases, including different types of neurodegenerative disorders. Microglia, the primary immune effector cells in the central nervous system, are implicated in these disorders by producing harmful substances such as reactive oxygen species (ROS). The protective mechanisms which scavenge ROS include enzymes and antioxidant substances. The protective effects of different carotenoids against oxidative stress have been described previously. Our study focuses on the effects of lutein on antioxidant enzymes, cytokines and iron metabolism under stress conditions in BV-2 microglia. We performed cell culture experiments: BV-2 cells were treated with lutein and/or with H₂O₂; the latter was used for inducing oxidative stress in microglial cells. Real-time PCR was performed for gene expression analyses of antioxidant enzymes, and ELISA was used for the detection of pro- and anti-inflammatory cytokines. Our results show that the application of lutein suppressed the H₂O₂-induced ROS (10′: 7.5 ng + 10 µM H₂O₂, p = 0.0002; 10 ng/µL + 10 µM H₂O₂, p = 0.0007), influenced iron utilization and changed the anti-inflammatory and pro-inflammatory cytokine secretions in BV-2 cells. Lutein increased the IL-10 secretions compared to control (24 h: 7.5 ng/µL p = 0.0274; 10 ng/µL p = 0.0008) and to 10 µM H₂O₂-treated cells (24 h: 7.5 ng/µL + H₂O₂, p = 0.0003; 10 ng/µL + H₂O₂, p = 0.0003), while it decreased the TNFα secretions compared to H₂O₂ treated cells (24 h: 7.5 ng/µL + H₂O₂, p < 0.0001; 10 ng/µL + H₂O₂, p < 0.0001). These results contribute to understanding the effects of lutein, which may help in preventing or suppressing ROS-mediated microglia activation, which is related to neuronal degeneration in oxidative stress scenario.

The effect of lutein and Urtica dioica extract on in vitro production of embryo and oxidative status in polycystic ovary syndrome in a model of mice

BACKGROUND

Polycystic ovary syndrome (PCOS) is one of the most prevalent endocrinopathies in women during the reproductive age. Herbal medicines are used increasingly alone or in supplement with chemical medicines for the treatment of different diseases and dysfunctions. This study was aimed to evaluate the effects of lutein and nettle (Urtica dioica) extract on the biochemical parameters and the reproductive function in the PCOS model of mice.

METHODS

Following the induction of PCOS by dehydroepiandrosterone (DHEA), the mice (n = 98) were randomly assigned into seven groups, each consisting of fourteen mice; the groups were included control group (received solvent), PCOS group (received 6 mg/100 g B.W/day IP, DHEA for 21 days), PCOS+ Nettle extract (200 and 400 mg/kg), PCOS+ Lutein (125 and 250 mg/kg), and PCOS+ NL (200 mg/kg nettle extract and 125 mg/kg lutein). The nettle extract and lutein were administrated using gavage for 30 consecutive days after PCOS induction. Malondialdehyde (MDA), total antioxidant capacity (TAC), and estrogen were measured in serum, ovary, and uterus samples by the ELISA method. The total number of oocytes, oocyte quality, fertilization rate, 2-cell blastocyst, and arrested embryos (type I, type II, and type III) were also investigated.

RESULTS

A combination treatment of the nettle and lutein produced the lowest concentration of MDA in comparison to other groups which affected by the PCOS. The lowest level of TAC was observed in the PCOS group without treatment. The number of oocytes, oocyte quality, fertilization rate, and 2-cell blastocyst were significantly higher in the control group, but the lowest values were observed in the PCOS group without any treatment.

CONCLUSIONS

The most favorable findings include improving antioxidant capacity, oocyte and embryo quality were observed in the PCOS+ 125 L group.

Xanthophyll: Health benefits and therapeutic insights

Xanthophylls constitute a major part of carotenoids in nature. They are an oxidized version of carotenoid. Xanthophyll has widely drawn scientists' attentions in terms of its functionality, bioavailability and diversity. An assortment of xanthophyll varieties includes lutein, zeaxanthin, β-cryptoxanthin, capsanthin, astaxanthin, and fucoxanthin. Chemically, lutein and zeaxanthin are dipolar carotenoids with hydroxyl groups at both ends of their molecules that bestow hydrophilic properties to them. Hydrophilic affinity in lutein and zeaxanthin makes better bioavailability in reaction with singlet oxygen in water phase, whereas non-polar carotenoids have shown to have less efficiency in scavenging free radicals. Xanthophylls have been studied for their effects in a wide variety of diseases including neurologic, ophthalmologic, oral, allergic and immune diseases. This review highlights pharmaco-pharmaceutical applications of xanthophylls as well asits drug interactions with beta-carotene. Different types of xanthophylls have been shown to have neuroprotective effects. Fucoxanthin demonstrated potent antiplasmodial activity. Lutein and zeaxanthin prevent the progression of age related macular degeneration. They have also demonstrated promising effects on uveitis, retinitis pigmentosa, scleritis, cataracts, glaucoma, retinal ischemia and choroideremia. Astaxanthin showed to have skin protecting effects against ultraviolet light injury. Astaxanthin have anti-allergic activity against the contact dermatitis especially to treat the patients having adverse reactions induced by steroids. Astaxanthin has been reported to exert beneficial effects in preventing oral lichen planus and early stage cancers. β-cryptoxanthin has been considered a good candidate for prevention of bone loss via osteoblastic bone formation and inhibiting osteoclastic bone resorption. There is also some concern that higher dose of xanthophylls may be linked to increased risk of skin cancer and gastric adenocarcinoma. However this increased risk was not statistically significant when adjusted for confounding factors. Further researches including clinical studies are needed to better evaluate the efficacy and safety of xanthophylls in prevention and treatment of different diseases.

A Systematic Review of Potential Therapeutic Use of Lycium Barbarum Polysaccharides in Disease

Objective

To evaluate the effect of Lycium barbarum polysaccharides in the treatment and/or prevention of diseases of different etiologies and systems.

Methods

We performed an Entrez PubMed literature search using keywords “lycium”, “barbarum”, “polysaccharides”, “anti-fibrotic”, “anti-apoptotic”, “anti-oxidizing”, “anti-aging”, “neuroprotection”, “metabolism”, “diabetes”, “hyperlipidemia”, “neuroprotection”, and “immunomodulation” on the 14^th of August 2018, resulting in 207 papers, of which 20 were chosen after filtering for ‘English language' and ‘published within 10 years' as well as curation for relevance by the authors.

Results

The 20 selected papers included 2 randomized control trials (1 double-blinded RCT and 1 double-blinded placebo-controlled RCT), 11 in vivo studies, 5 in vitro studies, 1 study with both in vivo and in vitro results, and 1 chemical study. There is good evidence from existing studies on the antifibrotic, antioxidizing, neuroprotective, anticancer, and anti-inflammatory effects of Lycium barbarum polysaccharides. However, there is a need for further studies in the form of large-scale clinical trials to support its use in humans. There is also significant potential for LBP as a safe and effective topical treatment in ocular surface diseases, owing to promising in vitro results and a lack of demonstrated toxic effects to corneal epithelial cells.

Conclusion

Results from existing studies suggest that LBP is a promising therapeutic agent, particularly in the management of liver disease, hyperlipidemia, and diabetes. One major limitation of current research is a lack of standardization and quality control for the LBP used. The availability of research-grade LBP will inevitably promote future research in this field worldwide.

Burn-Induced Multiple Organ Injury and Protective Effect of Lutein in Rats

Thermal injury may lead to multiple organ dysfunction through release of proinflammatory mediators and reactive oxygen radicals. This study investigated the effects of thermal injury on remote organs of rats and the possible protective effect of lutein. Thermal trauma was induced in the back of rats by exposing them to 90 °C bath for 10 s. Rats were sacrificed 48 h after burn, and blood samples were collected to monitor liver and kidney functions. Tissue samples from liver, kidneys, and lungs were taken for studying oxidative stress parameters, gene expressions of TNF-α and Casp-3, besides histopathological examination. Skin scald injury caused significant elevations of liver and kidney function biomarkers in the serum. In tissue samples, increments of MDA, GPx, and 8-OHdG were recorded while GSH level and the activities of CAT and SOD were suppressed. The expressions of TNF-α and caspase-3 mRNA were increased, and histopathological results revealed remote organ injury. Oral administration of lutein (250 mg/kg) resulted in amelioration of the biochemical and molecular changes induced by burn as well as the histopathological alterations. According to the findings of the present study, lutein possesses anti-oxidant, anti-inflammatory, and anti-apoptotic effects that protect against burn-induced damage in remote organs.

Lutein Suppresses Oxidative Stress and Inflammation by Nrf2 Activation in an Osteoporosis Rat Model

Background

Osteoporosis is a major health risk for women worldwide. Osteoporosis is caused by an imbalance between bone resorption and formation. Hormonal imbalance and increased redox signaling cause bone deterioration.

Material/Methods

Oxidative stress was determined through assessment of ROS, lipid peroxide levels, and antioxidant activity. Inflammatory protein markers and Nrf2-related protein expressions were determined through Western blot analysis. Interleukin expressions were determined using ELSA.

Results

In the present study, we showed that supplementation of lutein protects the ovariectomized (OVX) rats against oxidative stress through its antioxidant protection. OVX rats showed an increase in oxidative stress markers. Lutein treatment significantly decreased the lipid peroxidation levels and ROS in the OVX rats. OVX rats showed inflammatory responses through NF-κB activation and increased inflammatory cytokines (TNF-α, IL-6, IL-8). Further, there was significant upregulation in osteoclast-specific marker NFATc1 in OVX rats compared to sham rats. Lutein supplementation activated Nrf2 driven antioxidant gene expression (HO-1, NQO1) and protected OVX rats against inflammatory responses.

Conclusions

We showed the critical role of Lutein in protection against osteoporosis in OVX rats by downregulation of inflammation and osteoclast-specific marker (NFATc1) expression through Nrf2 activation.

Protective effects of radish (Raphanus sativus L.) leaves extract against hydrogen peroxide-induced oxidative damage in human fetal lung fibroblast (MRC-5) cells

Natural antioxidants play a critical role in the promotion of good health for its prevention of oxidative stress. The main purpose of this study is to investigate the protective effects of radish leaves extract on the oxidative damage in human fetal lung fibroblast (MRC-5) cells. F2, a fraction of radish leaves extracts, which was fractionated by different polarity solvents and AB-8 macroporous resins column shows the best free radical scavenging ability, the highest total polyphenol contents (TPC), and the most potent protective effects on H₂O₂-induced oxidative damage in MRC-5 cells. The results indicated that pretreatment with F2 before the exposure of cells to H₂O₂ led to a significant increase in cell viability and internal antioxidant enzyme activities, and a decrease in the content of malondialdehyde (MDA). Furthermore, F2 attenuated the increase in intracellular reactive oxygen species (ROS) level and restored the loss of mitochondria membrane potential (MMP) caused by H₂O₂. In addition, pretreatment of F2 down-regulated the pro-apoptosis protein (Bax) and up-regulated the anti-apoptosis protein (Bcl-2) suggested its preliminary mechanism of protective effect. In summary, F2 from radish leaves might be used as a source of antioxidant for protecting the oxidative damage of lung.

Lutein prevents osteoarthritis through Nrf2 activation and downregulation of inflammation

INTRODUCTION

Osteoarthritis is an inflammatory disorder associated with oxidative stress and apoptosis leading to cartilage destruction and impairment of cartilage formation. In the present study, we studied the protective effect of lutein against monosodium iodoacetate (MIA)-induced osteoarthritis in primary chondrocyte cells.

MATERIAL AND METHODS

Oxidative stress was determined through testing antioxidant status, reactive oxygen species levels and lipid peroxide content. Also, Nrf2 expression and its downstream target genes HO-1 and NQO-1 were determined. Inflammation was analyzed through NF-κB, COX-2 and pro-inflammatory cytokines (IL-6, TNF-α, IL-1β). In addition, the effects of MIA and lutein on mitochondrial membrane potential and caspase-3 levels were analyzed.

RESULTS

The results showed that lutein treatment significantly increased the cell viability of chondrocytes and offered significant cytoprotection by enhancing the antioxidant defense mechanisms and reducing oxidative stress (reactive oxygen species and lipid peroxidation). Lutein treatment showed anti-inflammatory effects by downregulating inflammatory proteins (NF-κB, COX-2) and pro-inflammatory cytokines (IL-6, TNF-α, IL-1β). Lutein reduced MIA-induced apoptosis through maintaining mitochondrial membrane potential and downregulating caspase-3 activity.

CONCLUSIONS

The present study shows significant cytoprotection offered by lutein against MIA-induced oxidative stress, inflammation and apoptosis by the modulatory effect of NF-κB and Nrf2 activation.

Molecular Cloning and Characterization of Carotenoid Pathway Genes and Carotenoid Content in Ixeris dentata var. albiflora

Ixeris dentata var. albiflora is considered as a potential therapeutic agent against mithridatism, calculous, indigestion, pneumonia, hepatitis, and tumors as well as good seasoned vegetable in Far East countries. Phytoene synthase (PSY), phytoene desaturase (PDS) ξ-carotene desaturase (ZDS), lycopene β-cyclase (LCYB), lycopene ε-cyclase (LCYE), ε-ring carotene hydroxylase (CHXB), and zeaxanthin epoxidase (ZDS) are vital enzymes in the carotenoid biosynthesis pathway. We have examined these seven genes from I. dentata that are participated in carotenoid biosynthesis utilizing an Illumina/Solexa HiSeq 2000 platform. In silico analysis of the seven deduced amino acid sequences were revealed its closest homology with other Asteracea plants. Further, we explored transcript levels and carotenoid accumulation in various organs of I. dentata using quantitative real time PCR and high-performance liquid chromatography, respectively. The highest transcript levels were noticed in the leaf for all the genes while minimal levels were noticed in the root. The maximal carotenoid accumulation was also detected in the leaf. We proposed that these genes expressions are associated with the accumulation of carotenoids. Our findings may suggest the fundamental clues to unravel the molecular insights of carotenoid biosynthesis in various organs of I. dentata.

Lutein and zeaxanthin isomers modulates lipid metabolism and the inflammatory state of retina in obesity-induced high-fat diet rodent model

Background

Several studies associated high-fat intakes with a high incidence of age-related macular degeneration (AMD). Lutein and Zeaxanthin isomers (L/Zi) may counteract reactive oxygen species produced by oxidative stress. The present study was conducted to determine the possible effects of L/Zi administration on lipid profile, protein genes associated with oxidative stress and inflammation pathways in the obesity induced by a high-fat diet (HFD) in rodents.

Methods

Twenty-eight male Wistar rats were allocated into four groups as follows: (i) Control, (ii) Control + L/Zi, (iii) High Fat Diet (HFD), and (iv) HFD+ L/Z. L/Zi was administrated for 8 weeks at a daily dose of 100 mg/kg BW.

Results

L/Zi administration significantly reduced insulin and free fatty acid (FFA) levels (P < 0.001) and ameliorated the oxidative damage by reducing malondialdehyde (MDA) concentration and increasing antioxidant enzymes activities of retina induced by HFD. In addition, supplementation decreased the levels of vascular endothelial growth factor (VEGF), inducible nitric oxide synthase (iNOS), nuclear factor-kappa B (NF-κB) and intercellular adhesion molecule-1 (ICAM) (P < 0.001, respectively) and improved nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase 1 (HO-1) gene proteins in retinal tissues (P < 0.001).

Conclusion

Rats fed with HFD exhibited increased oxidative stress and upregulation of inflammatory indicators. However, L/Zi supplementation modulates genes involved oxidative stress and inflammation including NF-κB and Nrf2 signaling pathways in the retina which may contribute to ameliorating retinal damage induced by HFD.

Effects of Lutein on Hyperosmoticity-Induced Upregulation of IL-6 in Cultured Corneal Epithelial Cells and Its Relevant Signal Pathways

Dry eye is a common disorder characterized by deficiency of tear. Hyperosmoticity of tear stimulates inflammation and damage of ocular surface tissues and plays an essential role in the pathogenesis of dry eye. Cultured human corneal epithelial (CE) cells were used for the study of effects of lutein and hyperosmoticity on the secretion of IL-6 by CE cells. Cell viability of CE cells was not affected by lutein at 1–10 μM as determined by MTT assay. Hyperosmoticity significantly elevated the secretion of IL-6 by CE cells as measured by ELISA analysis. The constitutive secretion of IL-6 was not affected by lutein. Lutein significantly and dose-dependently inhibited hyperosmoticity-induced secretion of IL-6. Phosphorylated- (p)- p38 MAPK, p-JNK levels in cell lysates and NF-κB levels in cell nuclear extracts were increased by being exposed to hyperosmotic medium. JNK, p38, and NF-κB inhibitors decreased hyperosmoticity-induced secretion of IL-6. Lutein significantly inhibited hyperosmoticity-induced elevation of NF-κB, p38, and p-JNK levels. We demonstrated that lutein inhibited hyperosmoticity-induced secretion of IL-6 in CE cells through the deactivation of p38, JNK, and NF-κB pathways. Lutein may be a promising agent to be explored for the treatment of dry eye.

Lutein derived fragments exhibit higher antioxidant and anti-inflammatory properties than lutein in lipopolysaccharide induced inflammation in rats

In the present study, we appraise the anti-inflammatory efficacy of lutein oxidative degradation derivatives mediated through UV-irradiation over lutein in counteracting the inflammation induced by lipopolysaccharide (LPS) in rats (n = 5 per group). UV-irradiated lutein fragments were identified as anhydrolutein (B, C40H54O), 2,6,6-trimethylcyclohexa-1,4-dienylium (M1, C9H13), (2E,4E,6E,8E)-9-(4-hydroxy-2,6,6-trimethylcyclohex-1-1en-1-yl)-3,7-dimethylnona-2,4,6,8-tetraen-1-ylium (M2, C20H29O), 4-[(1E,3E,5E,7E)-3,7,-dimethyldeca-1,3,5,7-tetraen-1-yl]-3,5,5-methylcyclohex-3-en-1-ol (M3, C21H30O) and zeaxanthin (M4, C40H56O) and its isomers as 13'-Z zeaxanthin, 13'-Z lutein, all-trans zeaxanthin, and 9-Z lutein. Induction of inflammation by LPS significantly increased the production of nitrites (3.3 fold in the serum and 2.6 fold in the liver), prostaglandin E2 (26 fold in the serum), and pro-inflammatory cytokines like tumor necrosis factor-α (6.6 fold in the serum), and interleukin-6 (4.8 fold in the serum). Oxidative derivatives of lutein, especially M1, M2 and M3, ameliorated acute inflammation in rats by inhibiting the production of nitrites, malondialdehyde (MDA), PGE2, TNF-α, and IL-6 cytokines more efficiently than lutein in rats. The anti-inflammatory mechanism of derivatives might be related to the decrease of inflammatory cytokines and the increase of antioxidant enzymes (superoxide dismutase, catalase, glutathione peroxidase, glutathione S transferase, glutathione reductase), which would result in the reduction of iNOS, COX-2 and MDA and subsequently inflammatory responses.

Management of Ocular Diseases Using Lutein and Zeaxanthin: What Have We Learned from Experimental Animal Studies?

Zeaxanthin and lutein are two carotenoid pigments that concentrated in the retina, especially in the macula. The effects of lutein and zeaxanthin on the prevention and treatment of various eye diseases, including age-related macular degeneration, diabetic retinopathy and cataract, ischemic/hypoxia induced retinopathy, light damage of the retina, retinitis pigmentosa, retinal detachment, and uveitis, have been studied in different experimental animal models. In these animal models, lutein and zeaxanthin have been reported to have beneficial effects in protecting ocular tissues and cells (especially the retinal neurons) against damage caused by different etiological factors. The mechanisms responsible for these effects of lutein and zeaxanthin include prevention of phototoxic damage by absorption of blue light, reduction of oxidative stress through antioxidant activity and free radical scavenging, and their anti-inflammatory and antiangiogenic properties. The results of these experimental animal studies may provide new preventive and therapeutic procedures for clinical management of various vision-threatening diseases.

Effects of Lutein and Zeaxanthin on LPS-Induced Secretion of IL-8 by Uveal Melanocytes and Relevant Signal Pathways

The effects of lutein and zeaxanthin on lipopolysaccharide- (LPS-) induced secretion of IL-8 by uveal melanocytes (UM) were tested in cultured human UM. MTT assay revealed that LPS (0.01-1 μg/mL) and lutein and zeaxanthin (1-10 μM) did not influence the cell viability of cultured UM. LPS caused a dose-dependent increase of secretion of IL-8 by cultured UM. Lutein and zeaxanthin did not affect the constitutive secretion of IL-8. However, lutein and zeaxanthin decreased LPS-induced secretion of IL-8 in cultured UM in a dose-dependent manner. LPS significantly increased NF-κB levels in cell nuclear extracts and p-JNK levels in the cell lysates from UM, but not p-p38 MAPK and p-ERG. Lutein or zeaxanthin significantly reduced LPS-induced increase of NF-κB and p-JNK levels, but not p38 MAPK and ERG levels. The present study demonstrated that lutein and zeaxanthin inhibited LPS-induced secretion of IL-8 in cultured UM via JNK and NF-κB signal pathways. The anti-inflammatory effects of lutein and zeaxanthin might be explored as a therapeutic approach in the management of uveitis and other inflammatory diseases of the eye.

Crosslinked chitosan-dextran sulfate nanoparticle for improved topical ocular drug delivery

PURPOSE

To examine the benefits of chitosan-dextran sulfate nanoparticles (CDNs) as a topical ocular delivery system with lutein as a model drug.

METHODS

CDNs were developed by polyelectrolyte complexation of positively charged chitosan (CS) and negatively charged dextran sulfate (DS). 1-Ethyl-3-(3-dimethylaminopropyl)-carbodiimide (EDC) and polyethylene glycol 400 (PEG400) were used as co-crosslinking and stabilizing agents, respectively. The influence of these on the properties of CDNs, including drug release and mucoadhesiveness, was examined. The chemical stability of lutein in CDNs (LCDNs) was also examined.

RESULTS

Typically, LCDNs showed a spherical shape, possessing a mean size of ~400 nm with a narrow size distribution. The entrapment efficiency of lutein was in the range of 60%-76%. LCDNs possessing a positive surface charge (+46 mV) were found to be mucoadhesive. The release profile of LCDNs followed Higuchi's square root model, suggesting drug release by diffusion from the polymer matrix. Lutein in LCDNs showed increased chemical stability during storage compared to its solution form.

CONCLUSIONS

These characteristics of CDNs make them suitable for drug delivery to the ocular surface.

Brewers’ rice modulates oxidative stress in azoxymethane-mediated colon carcinogenesis in rats

AIM: To investigate the mechanistic action of brewers’ rice in regulating the Wnt/nuclear factor-kappa B (NF-κB)/Nrf2-signaling pathways during colon carcinogenesis in male Sprague-Dawley rats.

METHODS: Male Sprague-Dawley rats were randomly divided into the following five groups (six rats in each group): (G1) normal, (G2) azoxymethane (AOM) alone, (G3) AOM + 10% (weight (w)/weight (w)) brewers’ rice, (G4) AOM + 20% (w/w) brewers’ rice, and (G5) AOM + 40% (w/w) brewers’ rice. They were intraperitoneally administered 15 mg/kg body weight of AOM in saline once weekly over a two-week period and treated with an American Institute of Nutrition (AIN)-93G diet containing 10%, 20%, and 40% (w/w) brewers’ rice. The mRNA levels of glycogen synthase kinase 3β (GSK3β), β-catenin, key inflammation markers, nuclear factor E2-related factor 2 (Nrf2), and heme oxygenase-1 (HO-1)-dependent transcriptional activity were assessed by quantitative real-time polymerase chain reaction analyses. The colon superoxide dismutase, malondialdehyde, and nitric oxide levels were also analyzed to assess the antioxidant effect of these treatments. The results were analyzed using one-way analysis of variance (ANOVA), and a P value of < 0.05 was considered significant.

RESULTS: The overall analyses demonstrated that the dietary administration of brewers’ rice in AOM-induced rat colon carcinogenesis resulted in the transcriptional upregulation of GSK3β, inducible nitric oxide synthase (iNOS), Nrf2, and HO-1. We discovered that the dietary administration of brewers’ rice downregulated the β-catenin and NF-κB mRNA levels. A significant reduction in β-catenin expression was found in the groups administered with 20% (0.611 ± 0.034) and 40% (0.436 ± 0.045) (w/w) brewers’ rice compared with that of the group treated with AOM alone (1.000 ± 0.064) (P < 0.05). The NF-κB expression was significantly lower between the AOM-alone group (1.000 ± 0.048) and those groups fed with diets containing 10% (w/w) brewers’ rice (0.255 ± 0.022), 20% (w/w) brewers’ rice (0.450 ± 0.045), or 40% (w/w) brewers’ rice (0.541 ± 0.027) (P < 0.05). Brewers’ rice improved the antioxidant levels, indicating that brewers’ rice can enhance effective recovery from oxidative stress induced by AOM.

CONCLUSION: Our results provide evidence that brewers’ rice can suppress colon cancer via the regulation of Nrf2 expression and the inhibition of the Wnt/NF-κB signaling pathways.

Lutein dietary supplementation attenuates streptozotocin-induced testicular damage and oxidative stress in diabetic rats

Background

Diabetes mellitus with the successive generation of reactive oxygen species signifies a major risk factor for testicular dysfunction. Antioxidant supplements are one of the best options to prevent such disorder. In the present study, lutein as dietary supplement has been used to explore its potential protective effects against diabetes-induced oxidative stress in testicular cells.

Methods

Diabetes was induced using a single IP injection of streptozotocin (STZ). Lutein was mixed with rat chow powder and supplemented to diabetic rats for 5 weeks. Serum testosterone levels were estimated. In testicular cells, thiobarbituric acid reactive substances (TBARS), total sulfhydryl groups (T-GSH), non-protein sulfhydryl groups (NP-SH), superoxide dismutase (SOD) and catalase (CAT) activities were measured. Pro-inflammatory mediators like tumor necrosis factor α (TNF-α) and interleukin 1β (IL-1β) were measured in the testis. Nucleic acids and total protein (TP) levels were also estimated in testicular cells. Histopathological changes were evaluated in testis.

Results

Serum testosterone level was significantly decreased in diabetic animals compared to controls. Diabetes markedly reduced T-GSH, NP-SH, CAT and SOD, while TBARS, TNF-α and IL-1β levels were increased in the diabetic testis compared to non-diabetic controls. Lutein supplementation, significantly and dose dependently increased the serum testosterone level. The elevated TBARS levels were significantly decreased compared to diabetic group, while the decreased levels of T-GSH and NP-SH and activities of CAT and SOD were found increased by lutein treatments in dose dependent manner. Lutein pretreatment also inhibited the TNF-α and IL-1β levels compared to diabetic group. The decreased values of nucleic acids and total protein in diabetic group were also significantly increased in lutein supplemented groups. The histopathological evaluation revealed protection the damaged testicular cells in the diabetic rats by lutein supplementation.

Conclusion

These findings showed that lutein has potential beneficial effects in diabetes-induced testicular damage, probably through its antioxidant and anti-inflammatory properties.

Diet carotenoid lutein modulates the expression of genes related to oxygen transporters and decreases DNA damage and oxidative stress in mice

Lutein (LT) is a carotenoid obtained by diet and despite its antioxidant activity had been biochemically reported, few studies are available concerning its influence on the expression of antioxidant genes. The expression of 84 genes implicated in antioxidant defense was quantified using quantitative reverse transcription polymerase chain reaction array. DNA damage was measured by comet assay and glutathione (GSH) and thiobarbituric acid reactive substances (TBARS) were quantified as biochemical parameters of oxidative stress in mouse kidney and liver. cDDP treatment reduced concentration of GSH and increased TBARS, parameters that were ameliorated in treatment associated with LT. cDDP altered the expression of 32 genes, increasing the expression of GPx2, APC, Nqo1 and CCs. LT changed the expression of 37 genes with an induction of 13 mainly oxygen transporters. In treatments associating cDDP and LT, 30 genes had their expression changed with a increase of the same genes of the cDDP treatment alone. These results suggest that LT might act scavenging reactive species and also inducing the expression of genes related to a better antioxidant response, highlighting the improvement of oxygen transport. This improved redox state of the cell through LT treatment could be related to the antigenotoxic and antioxidant effects observed.

Effects of constant light during perinatal periods on the behavioral and neuronal development of mice with or without dietary lutein

Constant light conditions (LL) carry a risk of disrupting the biological clock of developing animals. Our purpose in this study was to investigate what disorders occur in animals receiving an LL stress during the late embryonic and suckling periods as compared with animals housed in dark-light (14 h-10 h) conditions (DL). In addition, we examined ameliorating effects against the disorder by the oral administration of lutein as an antioxidant. LL caused hypertrophy of the spleen and induced a higher expression of serotonin transporter (5HTT) in the corpus striatum and hippocampus in 15-day-old pups. In 9-week-old offspring, LL caused abnormal behavior in the elevated plus-maze test. The expression levels of 5HTT in the brain of the LL group changed to lower than those in DL group. The oral administration of lutein lessened the abnormality in behavior and 5HTT expression in the hippocampus to a certain degree although the expression levels of 5HTT in the corpus striatum were not altered by lutein diet. LL also induced disorders in the maternal brain with lower expression levels of 5HTT and neuregulin 1. These results indicate that LL during the perinatal periods may induce some neuronal abnormalities in both offspring and mothers that may be partially ameliorated by dietary lutein as an antioxidant.

The role of lutein in eye-related disease

The lens and retina of the human eye are exposed constantly to light and oxygen. In situ phototransduction and oxidative phosphorylation within photoreceptors produces a high level of phototoxic and oxidative related stress. Within the eye, the carotenoids lutein and zeaxanthin are present in high concentrations in contrast to other human tissues. We discuss the role of lutein and zeaxanthin in ameliorating light and oxygen damage, and preventing age-related cellular and tissue deterioration in the eye. Epidemiologic research shows an inverse association between levels of lutein and zeaxanthin in eye tissues and age related degenerative diseases such as macular degeneration (AMD) and cataracts. We examine the role of these carotenoids as blockers of blue-light damage and quenchers of oxygen free radicals. This article provides a review of possible mechanisms of lutein action at a cellular and molecular level. Our review offers insight into current clinical trials and experimental animal studies involving lutein, and possible role of nutritional intervention in common ocular diseases that cause blindness.

Antioxidant and hepatoprotective effect of aqueous extract of germinated and fermented mung bean on ethanol-mediated liver damage

Mung bean is a hepatoprotective agent in dietary supplements. Fermentation and germination processes are well recognized to enhance the nutritional values especially the concentration of active compounds such as amino acids and GABA of various foods. In this study, antioxidant and hepatoprotective effects of freeze-dried mung bean and amino-acid- and GABA-enriched germinated and fermented mung bean aqueous extracts were compared. Liver superoxide dismutase (SOD), malondialdehyde (MDA), ferric reducing antioxidant power (FRAP), nitric oxide (NO) levels, and serum biochemical profile such as aspartate transaminase (AST), alanine transaminase (ALT), triglycerides (TG), and cholesterol and histopathological changes were examined for the antioxidant and hepatoprotective effects of these treatments. Germinated and fermented mung bean have recorded an increase of 27.9 and 7.3 times of GABA and 8.7 and 13.2 times of amino acid improvement, respectively, as compared to normal mung bean. Besides, improvement of antioxidant levels, serum markers, and NO level associated with better histopathological evaluation indicated that these extracts could promote effective recovery from hepatocyte damage. These results suggested that freeze-dried, germinated, and fermented mung bean aqueous extracts enriched with amino acids and GABA possessed better hepatoprotective effect as compared to normal mung bean.