scholarly journals Effects of a Newly Developed Enzyme-Assisted Extraction Method on the Biological Activities of Fucoidans in Ocular Cells

Marine Drugs ◽  
2020 ◽  
Vol 18 (6) ◽  
pp. 282 ◽  
Author(s):  
Philipp Dörschmann ◽  
Maria Dalgaard Mikkelsen ◽  
Thuan Nguyen Thi ◽  
Johann Roider ◽  
Anne S. Meyer ◽  
...  
Keyword(s):  
High Performance ◽  
Biological Activities ◽  
Alginate Lyase ◽  
Extraction Methods ◽  
Exchange Chromatography ◽  
Age Related Macular Degeneration ◽  
Saccharina Latissima ◽  
Enzyme Linked Immunosorbent Assay ◽  
Protective Effects ◽  
Age Related

Fucoidans from brown seaweeds are promising substances as potential drugs against age-related macular degeneration (AMD). The heterogeneity of fucoidans requires intensive research in order to find suitable species and extraction methods. Ten different fucoidan samples extracted enzymatically from Laminaria digitata (LD), Saccharina latissima (SL) and Fucus distichus subsp. evanescens (FE) were tested for toxicity, oxidative stress protection and VEGF (vascular endothelial growth factor) inhibition. For this study crude fucoidans were extracted from seaweeds using different enzymes and SL fucoidans were further separated into three fractions (SL_F1-F3) by ion-exchange chromatography (IEX). Fucoidan composition was analyzed by high performance anion exchange chromatography (HPAEC) after acid hydrolysis. The crude extracts contained alginate, while two of the fractionated SL fucoidans SL_F2 and SL_F3 were highly pure. Cell viability was assessed with an 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) assay in OMM-1 and ARPE-19. Protective effects were investigated after 24 h of stress insult in OMM-1 and ARPE-19. Secreted VEGF was analyzed via ELISA (enzyme-linked immunosorbent assay) in ARPE-19 cells. Fucoidans showed no toxic effects. In OMM-1 SL_F2 and several FE fucoidans were protective. LD_SiAT2 (Cellic®CTec2 + Sigma-Aldrich alginate lyase), FE_SiAT3 (Cellic® CTec3 + Sigma-Aldrich alginate lyase), SL_F2 and SL_F3 inhibited VEGF with the latter two as the most effective. We could show that enzyme treated fucoidans in general and the fractionated SL fucoidans SL_F2 and SL_F3 are very promising for beneficial AMD relevant biological activities.

scholarly journals Comparison of the Effects of Fucoidans on the Cell Viability of Tumor and Non-Tumor Cell Lines

Marine Drugs ◽  
2019 ◽  
Vol 17 (8) ◽  
pp. 441 ◽  
Author(s):  
Bittkau ◽  
Dörschmann ◽  
Blümel ◽  
Tasdemir ◽  
Roider ◽  
...  
Keyword(s):  
Cell Viability ◽  
Tumor Cells ◽  
Cell Lines ◽  
Biological Activities ◽  
Tumor Therapy ◽  
Age Related Macular Degeneration ◽  
Saccharina Latissima ◽  
Total Phenolic ◽  
Age Related ◽  
Hct 116

Fucoidans extracted from brown algae exert manifold biological activities paving the way for the development of numerous applications including treatments outside tumor therapy such as age-related macular degeneration or tissue engineering. In this study, we investigated the antiproliferative effects of fucoidans extracted from six different algae (Fucus vesiculosus, F. serratus, F. distichus subsp. evanescens, Dictyosiphon foeniculaceus, Laminaria digitata, Saccharina latissima) as well as three reference compounds (Sigma fucoidan, heparin, enoxaparin) on tumor (HL-60, Raji, HeLa, OMM-1, A-375, HCT-116, Hep G2) and non-tumor (ARPE-19, HaCaT) cell lines. All fucoidans were extracted according to a standardized procedure and tested in a commercially available MTS assay. Cell viability was measured after 24 h incubation with test compounds (1–100 µg/mL). Apart from few exceptions, fucoidans and heparins did not impair cell viability. In contrast, fucoidans significantly increased cell viability of suspension cell lines, but not of adherent cells. Fucoidans slightly increased viability of tumor cells and had no impact on the viability of non-tumor cells. The cell viability of HeLa and ARPE-19 cells negatively correlated with protein content and total phenolic content (TPC) of fucoidans, respectively. In summary, none of the tested fucoidans turned out to be anti-proliferative, rendering them interesting for future studies and applications.

scholarly journals Plasma Lutein, a Nutritional Biomarker for Development of Advanced Age-Related Macular Degeneration: The Alienor Study

Nutrients ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 2047
Author(s):  
Bénédicte M. J. Merle ◽  
Audrey Cougnard-Grégoire ◽  
Jean-François Korobelnik ◽  
Wolfgang Schalch ◽  
Stéphane Etheve ◽  
...  
Keyword(s):  
Macular Degeneration ◽  
High Performance ◽  
Population Based ◽  
Age Related Macular Degeneration ◽  
Cox Proportional Hazard ◽  
Age Related ◽  
Cox Proportional Hazard Models ◽  
Adjusted Model ◽  
Reduced Risk

Lutein and zeaxanthin may lower the risk of age-related macular degeneration (AMD). We evaluated the associations of plasma lutein and zeaxanthin with the incidence of advanced AMD in the Alienor study (Antioxydants Lipides Essentiels Nutrition et Maladies Oculaires). Alienor study is a prospective population-based cohort of 963 residents of Bordeaux, France, who were 73 years or older at baseline (2006–2008). The present study included 609 participants with complete ophthalmologic and plasma carotenoids data. Examinations were performed every two years over an eight-year period (2006 to 2017). Plasma lutein and zeaxanthin were determined at baseline from fasting blood samples using high-performance liquid chromatography. Cox proportional hazard models were used to assess associations between plasma lutein, zeaxanthin, and their (total cholesterol (TC) + triglycerides (TG)) ratios with AMD. Among the 609 included participants, 54 developed advanced incident AMD during a median follow-up time of 7.6 years (range 0.7 to 10.4). Participants with higher plasma lutein had a reduced risk for incident advanced AMD in the fully adjusted model (HR = 0.63 per 1-SD increase (95% CI, 0.41–0.97), p = 0.03). A similar association was observed using the lutein/(TC + TG) ratio (HR = 0.59 (95% CI, 0.39–0.90), p = 0.01). No associations were evidenced for other carotenoids. Higher plasma lutein was associated with a 37% reduced risk of incident advanced AMD.

scholarly journals Development of an ultra-sensitive human IL-33 biomarker assay for age-related macular degeneration and asthma drug development

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Elaine Mai ◽  
Joyce Chan ◽  
Levina Goon ◽  
Braeden K. Ego ◽  
Jack Bevers ◽  
...  
Keyword(s):  
Macular Degeneration ◽  
Inflammatory Diseases ◽  
Interleukin 1 ◽  
Age Related Macular Degeneration ◽  
Reduced Form ◽  
Enzyme Linked Immunosorbent Assay ◽  
Interleukin 33 ◽  
Age Related ◽  
Significant Difference ◽  
High Concentrations

Abstract Background Over the past decade, human Interleukin 33 (hIL-33) has emerged as a key contributor to the pathogenesis of numerous inflammatory diseases. Despite the existence of several commercial hIL-33 assays spanning multiple platform technologies, their ability to provide accurate hIL-33 concentration measurements and to differentiate between active (reduced) and inactive (oxidized) hIL-33 in various matrices remains uncertain. This is especially true for lower sample volumes, matrices with low hIL-33 concentrations, and matrices with elevated levels of soluble Interleukin 1 Receptor-Like 1 (sST2), an inactive form of ST2 that competes with membrane bound ST2 for hIL-33 binding. Results We tested the performance of several commercially available hIL-33 detection assays in various human matrices and found that most of these assays lacked the sensitivity to accurately detect reduced hIL-33 at biologically relevant levels (sub-to-low pg/mL), especially in the presence of human sST2 (hsST2), and/or lacked sufficient target specificity. To address this, we developed and validated a sensitive and specific enzyme-linked immunosorbent assay (ELISA) capable of detecting reduced and total hIL-33 levels even in the presence of high concentrations of sST2. By incorporating the immuno-polymerase chain reaction (iPCR) platform, we further increased the sensitivity of this assay for the reduced form of hIL-33 by ~ 52-fold. Using this hIL-33 iPCR assay, we detected hIL-33 in postmortem human vitreous humor (VH) samples from donors with age-related macular degeneration (AMD) and found significantly increased hIL-33 levels when compared to control individuals. No statistically significant difference was observed in aqueous humor (AH) from AMD donors nor in plasma and nasosorption fluid (NF) from asthma patients compared to control individuals. Conclusions Unlike existing commercial hIL-33 assays, our hIL-33 bioassays are highly sensitive and specific and can accurately quantify hIL-33 in various human clinical matrices, including those with high levels of hsST2. Our results provide a proof of concept of the utility of these assays in clinical trials targeting the hIL-33/hST2 pathway.

scholarly journals Potential TSPO Ligand and Photooxidation Quencher Isorenieratene from Arctic Ocean Rhodococcus sp. B7740

Marine Drugs ◽  
2019 ◽  
Vol 17 (6) ◽  
pp. 316 ◽  
Author(s):  
Yashu Chen ◽  
Mengyao Guo ◽  
Jifang Yang ◽  
Jigang Chen ◽  
Bijun Xie ◽  
...  
Keyword(s):  
Arctic Ocean ◽  
Oxidation Process ◽  
Cell Model ◽  
Age Related Macular Degeneration ◽  
The Arctic ◽  
Protective Effects ◽  
Uvb Radiation ◽  
Age Related ◽  
Active Natural ◽  
Rhodococcus Sp

Due to its special aromatic structure, isorenieratene is thought to be an active natural antioxidant and photo/UV damage inhibitor. In this work, isorenieratene that was extracted from Rhodococcus sp. B7740 isolated from the Arctic Ocean, showed excellent scavenging ability of both singlet oxygen and hydroxyl radical in the UVB-induced auto-oxidation process using the EPR method. Within an ARPE-19 cell model damaged by UVB radiation, isorenieratene showed fine protective effects (1.13 ± 0.03 fold) compared with macular xanthophylls (MXs) through upregulating of tspo. The molecular docking was firstly performed to investigate the interaction of isorenieratene with TSPO as a special ligand. Results showed isorenieratene might form a better binding conformation (S-score −8.5438) than MXs and indicate that isorenieratene not only can function as a direct antioxidant but also activate tspo in ARPE-19 cells. Thus, isorenieratene might ease the UV-related damages including age-related macular degeneration (AMD).

scholarly journals Mechanisms and Treatment of Light-Induced Retinal Degeneration-Associated Inflammation: Insights from Biochemical Profiling of the Aqueous Humor

2020 ◽  
Vol 21 (3) ◽  
pp. 704 ◽  
Author(s):  
Dmitry V. Chistyakov ◽  
Viktoriia E. Baksheeva ◽  
Veronika V. Tiulina ◽  
Sergei V. Goriainov ◽  
Nadezhda V. Azbukina ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Retinal Degeneration ◽  
Aqueous Humor ◽  
Rabbit Model ◽  
Age Related Macular Degeneration ◽  
Protective Effects ◽  
Cyclooxygenase Inhibitor ◽  
Degenerative Diseases ◽  
Age Related ◽  
Retinal Degenerative Diseases

Ocular inflammation contributes to the pathogenesis of blind-causing retinal degenerative diseases, such as age-related macular degeneration (AMD) or photic maculopathy. Here, we report on inflammatory mechanisms that are associated with retinal degeneration induced by bright visible light, which were revealed while using a rabbit model. Histologically and electrophysiologically noticeable degeneration of the retina is preceded and accompanied by oxidative stress and inflammation, as evidenced by granulocyte infiltration and edema in this tissue, as well as the upregulation of total protein, pro-inflammatory cytokines, and oxidative stress markers in aqueous humor (AH). Consistently, quantitative lipidomic studies of AH elucidated increase in the concentration of arachidonic (AA) and docosahexaenoic (DHA) acids and lyso-platelet activating factor (lyso-PAF), together with pronounced oxidative and inflammatory alterations in content of lipid mediators oxylipins. These alterations include long-term elevation of prostaglandins, which are synthesized from AA via cyclooxygenase-dependent pathways, as well as a short burst of linoleic acid derivatives that can be produced by both enzymatic and non-enzymatic free radical-dependent mechanisms. The upregulation of all oxylipins is inhibited by the premedication of the eyes while using mitochondria-targeted antioxidant SkQ1, whereas the accumulation of prostaglandins and lyso-PAF can be specifically suppressed by topical treatment with cyclooxygenase inhibitor Nepafenac. Interestingly, the most prominent antioxidant and anti-inflammatory benefits and overall retinal protective effects are achieved by simultaneous administrating of both drugs indicating their synergistic action. Taken together, these findings provide a rationale for using a combination of mitochondria-targeted antioxidant and cyclooxygenase inhibitor for the treatment of inflammatory components of retinal degenerative diseases.

scholarly journals Protective Effect of Metformin against Hydrogen Peroxide-Induced Oxidative Damage in Human Retinal Pigment Epithelial (RPE) Cells by Enhancing Autophagy through Activation of AMPK Pathway

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Xia Zhao ◽  
Linlin Liu ◽  
Yizhou Jiang ◽  
Marta Silva ◽  
Xuechu Zhen ◽  
...  
Keyword(s):  
Oxidative Damage ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Age Related Macular Degeneration ◽  
Protective Effects ◽  
Rpe Cells ◽  
Mitochondria Membrane Potential ◽  
Ampk Pathway ◽  
Age Related ◽  
Diabetes Drug

Age-related macular degeneration (AMD) is a leading cause of blindness with limited effective treatment. Although the pathogenesis of this disease is complex and not fully understood, the oxidative damage caused by excessive reactive oxygen species (ROS) in retinal pigment epithelium (RPE) has been considered as a major cause. Autophagy is essential for the degradation of cellular components damaged by ROS, and its dysregulation has been implicated in AMD pathogenesis. Therefore, strategies aiming to boost autophagy could be effective in protecting RPE cells from oxidative damage. Metformin is the first-line anti-type 2 diabetes drug and has been reported to stimulate autophagy in many tissues. We therefore hypothesized that metformin may be able to protect RPE cells against H2O2-induced oxidative damage by autophagy activation. In the present study, we found that metformin attenuated H2O2-induced cell viability loss, apoptosis, elevated ROS levels, and the collapse of the mitochondria membrane potential in D407 cells. Autophagy was stimulated by metformin, and inhibition of autophagy by 3-methyladenine (3-MA) and chloroquine (CQ) or knockdown of Beclin1 and LC3B blocked the protective effects of metformin. In addition, we showed that metformin could activate the AMPK pathway, whereas both pharmacological and genetic inhibitions of AMPK blocked the autophagy-stimulating and protective effects of metformin. Metformin conferred a similar protection against H2O2-induced oxidative damage in primary cultured human RPE cells. Taken together, these results demonstrate that metformin could protect RPE cells from H2O2-induced oxidative damage by stimulating autophagy via the activation of the AMPK pathway, supporting its potential use in the prevention and treatment of AMD.

scholarly journals Prediction of age-related macular degeneration disease using a sequential deep learning approach on longitudinal SD-OCT imaging biomarkers

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Imon Banerjee ◽  
Luis de Sisternes ◽  
Joelle A. Hallak ◽  
Theodore Leng ◽  
Aaron Osborne ◽  
...  
Keyword(s):  
Clinical Trial ◽  
High Performance ◽  
Cross Validation ◽  
Time Frame ◽  
Age Related Macular Degeneration ◽  
Imaging Biomarkers ◽  
Imaging Features ◽  
Short Term ◽  
Age Related ◽  
Proposed Model

Abstract We propose a hybrid sequential prediction model called “Deep Sequence”, integrating radiomics-engineered imaging features, demographic, and visual factors, with a recursive neural network (RNN) model in the same platform to predict the risk of exudation within a future time-frame in non-exudative AMD eyes. The proposed model provides scores associated with risk of exudation in the short term (within 3 months) and long term (within 21 months), handling challenges related to variability of OCT scan characteristics and the size of the training cohort. We used a retrospective clinical trial dataset that includes 671 AMD fellow eyes with 13,954 observations before any signs of exudation for training and validation in a tenfold cross validation setting. Deep Sequence achieved high performance for the prediction of exudation within 3 months (0.96 ± 0.02 AUCROC) and within 21 months (0.97 ± 0.02 AUCROC) on cross-validation. Training the proposed model on this clinical trial dataset and testing it on an external real-world clinical dataset showed high performance for the prediction within 3-months (0.82 AUCROC) but a clear decrease in performance for the prediction within 21-months (0.68 AUCROC). While performance differences at longer time intervals may be derived from dataset differences, we believe that the high performance and generalizability achieved in short-term predictions may have a high clinical impact allowing for optimal patient follow-up, adding the possibility of more frequent, detailed screening and tailored treatments for those patients with imminent risk of exudation.

scholarly journals Methodology for quantitative determination of the carbohydrate composition of brown seaweeds (Laminariaceae)

RSC Advances ◽  
2014 ◽  
Vol 4 (49) ◽  
pp. 25736-25746 ◽  
Author(s):  
D. Manns ◽  
A. L. Deutschle ◽  
B. Saake ◽  
A. S. Meyer
Keyword(s):  
High Performance ◽  
Monosaccharide Composition ◽  
Anion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Saccharina Latissima ◽  
Carbohydrate Composition ◽  
Laminaria Digitata ◽  
Brown Seaweeds ◽  
Cellulase Treatment

The monosaccharide composition of four different samples of brown seaweeds Laminaria digitata and Saccharina latissima were compared by different high performance anion exchange chromatography (HPAEC) methods after different acid hydrolysis treatments or a cellulase treatment.

scholarly journals The Protective Role of Antioxidants in the Defence against ROS/RNS-Mediated Environmental Pollution

2014 ◽  
Vol 2014 ◽  
pp. 1-22 ◽  
Author(s):  
Borut Poljšak ◽  
Rok Fink
Keyword(s):  
Oxidative Stress ◽  
Nitrosative Stress ◽  
Environmental Pollutants ◽  
Protective Role ◽  
Age Related Macular Degeneration ◽  
Protective Effects ◽  
Age Related ◽  
Dietary Antioxidant ◽  
Polycyclic Aromatic ◽  
Antioxidant Supplements

Overproduction of reactive oxygen and nitrogen species can result from exposure to environmental pollutants, such as ionising and nonionising radiation, ultraviolet radiation, elevated concentrations of ozone, nitrogen oxides, sulphur dioxide, cigarette smoke, asbestos, particulate matter, pesticides, dioxins and furans, polycyclic aromatic hydrocarbons, and many other compounds present in the environment. It appears that increased oxidative/nitrosative stress is often neglected mechanism by which environmental pollutants affect human health. Oxidation of and oxidative damage to cellular components and biomolecules have been suggested to be involved in the aetiology of several chronic diseases, including cancer, cardiovascular disease, cataracts, age-related macular degeneration, and aging. Several studies have demonstrated that the human body can alleviate oxidative stress using exogenous antioxidants. However, not all dietary antioxidant supplements display protective effects, for example,β-carotene for lung cancer prevention in smokers or tocopherols for photooxidative stress. In this review, we explore the increases in oxidative stress caused by exposure to environmental pollutants and the protective effects of antioxidants.

scholarly journals A Review of the Analytical Methods for the Determination of 4(5)-Methylimidazole in Food Matrices

Chemosensors ◽  
2021 ◽  
Vol 9 (11) ◽  
pp. 322
Author(s):  
Panagiota-Kyriaki Revelou ◽  
Marinos Xagoraris ◽  
Eleftherios Alissandrakis ◽  
Christos S. Pappas ◽  
Petros A. Tarantilis
Keyword(s):  
Mass Spectrometry ◽  
Analytical Methods ◽  
High Performance ◽  
Water Solubility ◽  
Solid Phase ◽  
Sample Pretreatment ◽  
Extraction Methods ◽  
Exchange Chromatography ◽  
Food Matrices

4(5)-Methylimidazole (4(5)MEI) is a product of the Maillard reaction between sugars and amino acids, which occurs during the thermal processing of foods. This compound is also found in foods with caramel colorants additives. Due to its prevalence in foods and beverages and its potent carcinogenicity, 4(5)MEI has received federal and state regulatory agency attention. The aim of this review is to present the extraction procedures of 4(5)MEI from food matrices and the analytical methods for its determination. Liquid and gas chromatography coupled with mass spectrometry are the techniques most commonly employed to detect 4(5)MEI in food matrices. However, the analysis of 4(5)MEI is challenging due to the high polarity, water solubility, and the absence of chromophores. To overcome this, specialized sample pretreatment and extraction methods have been developed, such as solid-phase extraction and derivatization procedures, increasing the cost and the preparation time of samples. Other analytical methods for the determination of 4(5)MEI, include capillary electrophoresis, paper spray mass spectrometry, micellar electrokinetic chromatography, high-performance cation exchange chromatography, fluorescence-based immunochromatographic assay, and a fluorescent probe.

Sign in / Sign up

Export Citation Format

Share Document