scholarly journals Alpha-glucosidase inhibitory activity of some brown seaweeds collected in Nha Trang bay, Khanh Hoa province

2020 ◽  
Vol 19 (02) ◽  
pp. 90-98
Author(s):  
Han T. Nguyen
Keyword(s):  
Inhibitory Activity ◽  
Brown Seaweed ◽  
Postprandial Blood Glucose ◽  
Extraction Temperature ◽  
Brown Seaweeds ◽  
Extraction Solvent ◽  
Seaweed Extracts ◽  
Nha Trang Bay ◽  
Ic50 Values ◽  
Inhibited Enzyme

Diabetes has become a global problem in recent years. Inhibition of α-glucosidase is one of the effective approaches to control the postprandial blood glucose and thereby managing diabetes. This study evaluated inhibitory activity of seven brown seaweed extracts (Colpomenia sinuosa, Padina australis, Sargassum aquifolium, Sargassum mcclurei, Sargassum duplicatum, Sargassum polycystum and Sargassum swartzi) against α-glucosidase. The results indicated that all seaweed extracts inhibited enzyme activity with the IC50 values ranging from 154.27 to 426.27 μg/mL. The seaweed Sargassum mcclurei showed the highest α-glucosidase inhibitory activity. The effects of extraction conditions and extraction solvent fractions on α-glucosidase inhibitory activity of Sargassum mcclurei were investigated. The suitable extraction conditions were found to be the solid to liquid ratio (g/mL) of 1/40, the extraction time of 60 min and the extraction temperature of 60oC. The ethyl acetate extracted fraction showed the highest α-glucosidase inhibitory activity compared with other fractions.

scholarly journals Antibacterial potential of symbiont bacteria of brown algae (Turbinaria conoides) obtained from Indonesian waters

2020 ◽  
Vol 22 (1) ◽  
Author(s):  
Niken - Dharmayanti ◽  
ARMA ANTI ◽  
RESMI RUMENTA SIREGAR ◽  
YULIATI H. SIPAHUTAR ◽  
AEF PERMADI ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antibacterial Activity ◽  
Inhibitory Activity ◽  
Brown Seaweed ◽  
Internal Tissue ◽  
Brown Seaweeds ◽  
Turbinaria Conoides ◽  
Genotypic Analysis ◽  
Antibacterial Potential

Abstract. Dharmayanti N, Anti A, Siregar RR, Sipahutar Y, Permadi A, Siregar AN, Salampessy RB, Sujuliyanti, Nurbani SZ, Purnamasari HB. 2021. Title. Biodiversitas 22: 373-378. Brown seaweeds have the potential to produce bioactive compounds. Bacteria associated with seaweeds are involved in the production of metabolites. Microbes may be present as a living symbiotic in association with other algae as epiphytes or endophytes. In this study, bacteria isolated from brown seaweed (Turbinaria conoides) were tested for antibacterial activity. A total of 14 bacteria were isolated, of which 6 were isolated from external tissue, while 8 from internal tissue. Results of an antagonistic test revealed that 7 isolates showed inhibitory activity against Staphylococcus aureus and only 1 isolate showed the inhibition against both S. aureus and Escherichia coli. Phenotypic and genotypic analysis showed that the symbiont bacteria was Lactobacillus plantarum.

scholarly journals Comparison of edible brown algae extracts for the inhibition of intestinal carbohydrate digestive enzymes involved in glucose release from the diet

2021 ◽  
Vol 10 ◽  
Author(s):  
Maha Attjioui ◽  
Sinead Ryan ◽  
Aleksandra Konic Ristic ◽  
Thomas Higgins ◽  
Oscar Goñi ◽  
...  
Keyword(s):  
Brown Algae ◽  
Type Ii Diabetes ◽  
Digestive Enzymes ◽  
Brown Seaweed ◽  
Inhibitory Effect ◽  
Postprandial Blood Glucose ◽  
Type Ii ◽  
Seaweed Extracts ◽  
Gastrointestinal Side Effects ◽  
The Impact

Abstract Type II diabetes is considered the most common metabolic disorder in the developed world and currently affects about one in ten globally. A therapeutic target for the management of type II diabetes is the inhibition of α- glucosidase, an essential enzyme located at the brush border of the small intestinal epithelium. The inhibition of α-glucosidase results in reduced digestion of carbohydrates and a decrease in postprandial blood glucose. Although pharmaceutical synthetic inhibitors are available, these are usually associated with significant gastrointestinal side effects. In the present study, the impact of inhibitors derived from edible brown algae is being investigated and compared for their effect on glycaemic control. Carbohydrate- and polyphenolic-enriched extracts derived from Ascophyllum nodosum, Fucus vesiculosus and Undaria pinnatifida were characterised and screened for their inhibitory effects on maltase and sucrase enzymes. Furthermore, enzyme kinetics and the mechanism of inhibition of maltase and sucrase were determined using linear and nonlinear regression methods. All tested extracts showed a dose-dependent inhibitory effect of α-glucosidase with IC50 values ranging from 0⋅26 to 0⋅47 mg/ml for maltase; however, the only extract that was able to inhibit sucrase activity was A. nodosum, with an IC50 value of 0⋅83 mg/ml. The present study demonstrates the mechanisms in which different brown seaweed extracts with varying composition and molecular weight distribution differentially inhibit α-glucosidase activities. The data highlight that all brown seaweed extracts are not equal in the inhibition of carbohydrate digestive enzymes involved in postprandial glycaemia.

Inhibition of Protein Tyrosine Phosphatase 1B by Lutein Derivatives isolated from Mexican Oregano (Lippia graveolens)

2018 ◽  
Vol 17 (3) ◽  
pp. 134-139
Author(s):  
R.M. Perez-Gutierrez
Keyword(s):  
Protein Tyrosine Phosphatase ◽  
Inhibitory Activity ◽  
Spectroscopic Data ◽  
Methanol Extract ◽  
Tyrosine Phosphatase ◽  
Positive Control ◽  
Protein Tyrosine Phosphatase 1B ◽  
Protein Tyrosine ◽  
Ic50 Value ◽  
Ic50 Values

Methanol extract from Lippia graveolens (Mexican oregano) was studied in order to identify inhibitory bioactives for protein tyrosine phosphatase 1B (PTP1B). Known flavone as lutein (1), and another flavone glycoside such as lutein-7-o-glucoside (2), 6-hydroxy-lutein-7-ohexoside (3) and lutein-7-o-ramnoide (4) were isolated from methanol extract of aerial parts of the Lippia graveolens. All isolates were identified based on extensive spectroscopic data analysis, including UV, IR, NMR, MS and compared with spectroscopic data previously reported. These flavones were evaluated for PTP1B inhibitory activity. Among them, compounds 1 and 3 displayed potential inhibitory activity against PTP1B with IC50 values of 7.01 ± 1.25 μg/ml and 18.4 μg/ml, respectively. In addition, compound 2 and 4 showed moderate inhibitory activity with an IC50 value of 23.8 ± 6.21 and 67.8 ± 5.80 μg/ml respectively. Among the four compounds, luteolin was found to be the most potent PTP1B inhibitor compared to the positive control ursolic acid, with an IC50 value of 8.12 ± 1.06 μg/ml. These results indicate that flavonoids constituents contained in Lippia graveolens can be considered as a natural source for the treatment of type 2 diabetes.

scholarly journals Fine-Tuning the Biological Profile of Multitarget Mitochondriotropic Antioxidants for Neurodegenerative Diseases

Antioxidants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 329
Author(s):  
Daniel Chavarria ◽  
Ophelie Da Silva ◽  
Sofia Benfeito ◽  
Sandra Barreiro ◽  
Jorge Garrido ◽  
...  
Keyword(s):  
Inhibitory Activity ◽  
Antioxidant Properties ◽  
Neuroblastoma Cells ◽  
Oxidation Potential ◽  
Fine Tuning ◽  
Mitochondrial Oxidative Stress ◽  
Electric Eel ◽  
Ic50 Values ◽  
System Extension ◽  
Inhibition Potency

Neurotransmitter depletion and mitochondrial dysfunction are among the multiple pathological events that lead to neurodegeneration. Following our previous studies related with the development of multitarget mitochondriotropic antioxidants, this study aims to evaluate whether the π-system extension on the chemical scaffolds of AntiOXCIN2 and AntiOXCIN3 affects their bioactivity and safety profiles. After the synthesis of four triphenylphosphonium (TPP+) conjugates (compounds 2–5), we evaluated their antioxidant properties and their effect on neurotransmitter-metabolizing enzymes. All compounds were potent equine butyrylcholinesterase (eqBChE) and moderate electric eel acetylcholinesterase (eeAChE) inhibitors, with catechols 4 and 5 presenting lower IC50 values than AntiOXCIN2 and AntiOXCIN3, respectively. However, differences in the inhibition potency and selectivity of compounds 2–5 towards non-human and human cholinesterases (ChEs) were observed. Co-crystallization studies with compounds 2–5 in complex with human ChEs (hChEs) showed that these compounds exhibit different binging modes to hAChE and hBChE. Unlike AntiOXCINs, compounds 2–5 displayed moderate human monoamine oxidase (hMAO) inhibitory activity. Moreover, compounds 4 and 5 presented higher ORAC-FL indexes and lower oxidation potential values than the corresponding AntiOXCINs. Catechols 4 and 5 exhibited broader safety windows in differentiated neuroblastoma cells than benzodioxole derivatives 2 and 3. Compound 4 is highlighted as a safe mitochondria-targeted antioxidant with dual ChE/MAO inhibitory activity. Overall, this work is a contribution for the development of dual therapeutic agents addressing both mitochondrial oxidative stress and neurotransmitter depletion.

scholarly journals Inhibitory Effects of Secondary Metabolites from the Lichen Stereocaulon evolutum on Protein Tyrosine Phosphatase 1B

Planta Medica ◽  
2021 ◽  
Author(s):  
Birgit Waltenberger ◽  
Françoise Lohézic-Le Dévéhat ◽  
Thi Huyen Vu ◽  
Olivier Delalande ◽  
Claudia Lalli ◽  
...  
Keyword(s):  
Protein Tyrosine Phosphatase ◽  
Inhibitory Activity ◽  
Tyrosine Phosphatase ◽  
Inhibitory Effect ◽  
Positive Control ◽  
Protein Tyrosine Phosphatase 1B ◽  
Protein Tyrosine ◽  
Ic50 Values ◽  
A Cell

AbstractProtein tyrosine phosphatase 1B plays a significant role in type 2 diabetes mellitus and other diseases and is therefore considered a new drug target. Within this study, an acetone extract from the lichen Stereocaulon evolutum was identified to possess strong protein tyrosine phosphatase 1B inhibition in a cell-free assay (IC50 of 11.8 µg/mL). Fractionation of this bioactive extract led to the isolation of seven known molecules belonging to the depsidones and the related diphenylethers and one new natural product, i.e., 3-butyl-3,7-dihydroxy-5-methoxy-1(3H)-isobenzofurane. The isolated compounds were evaluated for their inhibition of protein tyrosine phosphatase 1B. Two depsidones, lobaric acid and norlobaric acid, and the diphenylether anhydrosakisacaulon A potently inhibited protein tyrosine phosphatase 1B with IC50 values of 12.9, 15.1, and 16.1 µM, respectively, which is in the range of the protein tyrosine phosphatase 1B inhibitory activity of the positive control ursolic acid (IC50 of 14.4 µM). Molecular simulations performed on the eight compounds showed that i) a contact between the molecule and the four main regions of the protein is required for inhibitory activity, ii) the relative rigidity of the depsidones lobaric acid and norlobaric acid and the reactivity related to hydrogen bond donors or acceptors, which interact with protein tyrosine phosphatase 1B key amino acids, are involved in the bioactivity on protein tyrosine phosphatase 1B, iii) the cycle opening observed for diphenylethers decreased the inhibition, except for anhydrosakisacaulon A where its double bond on C-8 offsets this loss of activity, iv) the function present at C-8 is a determinant for the inhibitory effect on protein tyrosine phosphatase 1B, and v) the more hydrogen bonds with Arg221 there are, the more anchorage is favored.

scholarly journals Scale-Up Preparation of Crocins I and II from Gardeniajasminoides by a Two-Step Chromatographic Approach and Their Inhibitory Activity Against ATP Citrate Lyase

Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3137
Author(s):  
Shuguang Guan ◽  
Qiaoli Pu ◽  
Yinan Liu ◽  
Honghong Wu ◽  
Wenbo Yu ◽  
...  
Keyword(s):  
Inhibitory Activity ◽  
High Speed ◽  
Scale Up ◽  
Cost Effective ◽  
Atp Citrate Lyase ◽  
Gardenia Jasminoides ◽  
Citrate Lyase ◽  
Human Disorders ◽  
Ic50 Values ◽  
Counter Current

Crocins are highly valuable natural compounds for treating human disorders, and they are also high-end spices and colorants in the food industry. Due to the limitation of obtaining this type of highly polar compound, the commercial prices of crocins I and II are expensive. In this study, macroporous resin column chromatography combined with high-speed counter-current chromatography (HSCCC) was used to purify crocins I and II from natural sources. With only two chromatographic steps, both compounds were simultaneously isolated from the dry fruit of Gardenia jasminoides, which is a cheap herbal medicine distributed in a number of countries. In an effort to shorten the isolation time and reduce solvent usage, forward and reverse rotations were successively utilized in the HSCCC isolation procedure. Crocins I and II were simultaneously obtained from a herbal resource with high recoveries of 0.5% and 0.1%, respectively, and high purities of 98.7% and 99.1%, respectively, by HPLC analysis. The optimized preparation method was proven to be highly efficient, convenient, and cost-effective. Crocins I and II exhibited inhibitory activity against ATP citrate lyase, and their IC50 values were determined to be 36.3 ± 6.24 and 29.7 ± 7.41 μM, respectively.

scholarly journals Clinical Efficacy of Brown Seaweeds Ascophyllum nodosum and Fucus vesiculosus in the Prevention or Delay Progression of the Metabolic Syndrome: A Review of Clinical Trials

Molecules ◽  
2021 ◽  
Vol 26 (3) ◽  
pp. 714
Author(s):  
Enver Keleszade ◽  
Michael Patterson ◽  
Steven Trangmar ◽  
Kieran J. Guinan ◽  
Adele Costabile
Keyword(s):  
Metabolic Syndrome ◽  
Clinical Trials ◽  
Brown Seaweed ◽  
Public Health Problem ◽  
Ascophyllum Nodosum ◽  
Fucus Vesiculosus ◽  
Total Phenolic ◽  
World Population ◽  
Brown Seaweeds ◽  
The Metabolic Syndrome

Metabolic syndrome (MetS) is a global public health problem affecting nearly 25.9% of the world population characterised by a cluster of disorders dominated by abdominal obesity, high blood pressure, high fasting plasma glucose, hypertriacylglycerolaemia and low HDL-cholesterol. In recent years, marine organisms, especially seaweeds, have been highlighted as potential natural sources of bioactive compounds and useful metabolites, with many biological and physiological activities to be used in functional foods or in human nutraceuticals for the management of MetS and related disorders. Of the three groups of seaweeds, brown seaweeds are known to contain more bioactive components than either red and green seaweeds. Among the different brown seaweed species, Ascophyllum nodosum and Fucus vesiculosus have the highest antioxidant values and highest total phenolic content. However, the evidence base relies mainly on cell line and small animal models, with few studies to date involving humans. This review intends to provide an overview of the potential of brown seaweed extracts Ascophyllum nodosum and Fucus vesiculosus for the management and prevention of MetS and related conditions, based on the available evidence obtained from clinical trials.

scholarly journals Physicochemical Characterization, Antioxidant and Immunostimulatory Activities of Sulfated Polysaccharides Extracted from Ascophyllum nodosum

Molecules ◽  
2018 ◽  
Vol 23 (8) ◽  
pp. 1912 ◽  
Author(s):  
Ligen Chen ◽  
Yan Wang ◽  
Hui Yang ◽  
Han Li ◽  
Wei Xu ◽  
...  
Keyword(s):  
Glucuronic Acid ◽  
Physicochemical Characterization ◽  
Ascophyllum Nodosum ◽  
Food Supplement ◽  
Raw Material ◽  
Sulfated Polysaccharides ◽  
Extraction Temperature ◽  
Molecular Weights ◽  
Extraction Solvent ◽  
Fast Flow

Polysaccharides from Ascophyllum nodosum (AnPS) were extracted and purified via an optimized protocol. The optimal extraction conditions were as follows: extraction time of 4.3 h, extraction temperature of 84 °C and ratio (v/w, mL/g) of extraction solvent (water) to raw material of 27. The resulting yield was 9.15 ± 0.23% of crude AnPS. Two fractions, named AnP1-1 and AnP2-1 with molecular weights of 165.92 KDa and 370.68 KDa, were separated from the crude AnPS by chromatography in DEAE Sepharose Fast Flow and Sephacryl S-300, respectively. AnP1-1 was composed of mannose, ribose, glucuronic acid, glucose and fucose, and AnP2-1 was composed of mannose, glucuronic acid, galactose and fucose. AnPS, AnP1-1 and AnP2-1 exhibited high scavenging activities against ABTS radical and superoxide radical, and showed protective effect on H2O2-induced oxidative injury in RAW264.7 cells. Furthermore, the immunostimulatory activities of AnP1-1 and AnP2-1 were evaluated by Caco-2 cells, the results showed both AnP1-1 and AnP2-1 could significantly promote the production of immune reactive molecules such as interleukin (IL)-8, IL-1β, interferon (IFN)-γ, and tumor necrosis factor (TNF)-α. Therefore, the results suggest that AnPS and its two fractions may be explored as a potential functional food supplement.

scholarly journals Mammalian Arginase Inhibitory Activity of Methanolic Extracts and Isolated Compounds from Cyperus Species

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1694
Author(s):  
Kamel Arraki ◽  
Perle Totoson ◽  
Alain Decendit ◽  
Andy Zedet ◽  
Justine Maroilley ◽  
...  
Keyword(s):  
Inhibitory Activity ◽  
Methanolic Extract ◽  
Significant Inhibition ◽  
Isolation And Identification ◽  
Vasorelaxant Effect ◽  
Methanolic Extracts ◽  
Phytochemical Investigation ◽  
Ic50 Values ◽  
First Time

Polyphenolic enriched extracts from two species of Cyperus, Cyperus glomeratus and Cyperus thunbergii, possess mammalian arginase inhibitory capacities, with the percentage inhibition ranging from 80% to 95% at 100 µg/mL and 40% to 64% at 10 µg/mL. Phytochemical investigation of these species led to the isolation and identification of two new natural stilbene oligomers named thunbergin A-B (1–2), together with three other stilbenes, trans-resveratrol (3), trans-scirpusin A (4), trans-cyperusphenol A (6), and two flavonoids, aureusidin (5) and luteolin (7), which were isolated for the first time from C.thunbergii and C. glomeratus. Structures were established on the basis of the spectroscopic data from MS and NMR experiments. The arginase inhibitory activity of compounds 1–7 was evaluated through an in vitro arginase inhibitory assay using purified liver bovine arginase. As a result, five compounds (1, 4–7) showed significant inhibition of arginase, with IC50 values between 17.6 and 60.6 µM, in the range of those of the natural arginase inhibitor piceatannol (12.6 µM). In addition, methanolic extract from Cyperus thunbergii exhibited an endothelium and NO-dependent vasorelaxant effect on thoracic aortic rings from rats and improved endothelial dysfunction in an adjuvant-induced arthritis rat model.

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