scholarly journals Decursin Isolated fromAngelica gigasNakai Rescues PC12 Cells from Amyloidβ-Protein-Induced Neurotoxicity through Nrf2-Mediated Upregulation of Heme Oxygenase-1: Potential Roles of MAPK

2013 ◽  
Vol 2013 ◽  
pp. 1-14 ◽  
Author(s):  
Li Li ◽  
Ji-kun Du ◽  
Li-yi Zou ◽  
Tie Wu ◽  
Yong-woo Lee ◽  
...  
Keyword(s):  
Pc12 Cells ◽  
Nuclear Translocation ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Competitive Inhibitor ◽  
Heme Oxygenase 1 ◽  
Signal Pathways ◽  
Therapeutic Effects ◽  
Nrf2 Activation

Decursin (D), purified fromAngelica gigasNakai, has been proven to exert neuroprotective property. Previous study revealed that D reduced Aβ25‒35-induced cytotoxicity in PC12 cells. Our study explored the underlying mechanisms by which D mediates its therapeutic effectsin vitro. Pretreatment of cells with D diminished intracellular generation of ROS in response to Aβ25‒35. Western blot revealed that D significantly increased the expression and activity of HO-1, which was correlated with its protection against Aβ25‒35-induced injury. Addition of ZnPP, an HO-1 competitive inhibitor, significantly attenuated its protective effect in Aβ25‒35-treated cells, indicating the vital role of HO-1 resistance to oxidative injury. Moreover, D induced Nrf2 nuclear translocation, the upstream of HO-1 expression. While investigating the signaling pathways responsible for HO-1 induction, D activated ERK and dephosphorylated p38 in PC12 cells. Addition of U0126, a selective inhibitor of ERK, blocked D-induced Nrf2 activation and HO-1 induction and meanwhile reversed the protection of D against Aβ25‒35-induced cell death. These findings suggest D augments cellular antioxidant defense capacity through both intrinsic free radical scavenging activity and activation of MAPK signal pathways that leads to Nrf2 activation, and subsequently HO-1 induction, thereby protecting the PC12 cells from Aβ25‒35-induced oxidative cytotoxicity.

scholarly journals In vitro Antioxidant Activities of Maillard Reaction Products Produced in the Steaming Process of Polygonum multiflorum Root

2011 ◽  
Vol 6 (1) ◽  
pp. 1934578X1100600 ◽  
Author(s):  
Zhenli Liu ◽  
Yuanyan Liu ◽  
Zhimao Chao ◽  
Zhiqian Song ◽  
Chun Wang ◽  
...  
Keyword(s):  
Maillard Reaction ◽  
Antioxidant Activities ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Maillard Reaction Products ◽  
Therapeutic Effects ◽  
Reaction Products ◽  
Polygonum Multiflorum ◽  
Main Compound

The root of Polygonum multiflorum Thunb. (Heshouwu in Chinese) is one of the most popular herbs used in traditional Chinese medicine (TCM). However, after steam processing (Zhi-heshouwu in Chinese), the root is known to have different properties and medicinal values compared with Heshouwu. Eleven volatile Maillard reaction products were identified in the extract of Zhi-heshouwu, but not in that of Heshouwu. The new products were four furanones, two furans, two nitrogen compounds, one pyran, one alcohol and one sulfur compound. The antioxidant activities were compared between the extracts from Zhi-heshouwu and Heshouwu. The results showed that the extract from Zhi-heshouwu presented a higher 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity than the extract from Heshouwu, with IC50 values of 0.43 mg/mL and 2.9 mg/mL, respectively ( p<0.05). The hydroxyl radical scavenging activities of the two were similar (IC50 0.98 mg/mL and 1.45 mg/mL, respectively; p > 0.05). 5-Hydroxymethyl-furfural, a main compound in the extract of Zhi-heshouwu, showed IC50 values for scavenging DPPH radicals and hydroxyl radicals of 1.6 mg/mL and 0.24 mg/mL, respectively. The antioxidant activities of the extract from Zhi-heshouwu could partly explain the different therapeutic effects of Heshouwu and Zhi-heshouwu in TCM.

scholarly journals Characterization of Novel Synthetic Polyphenols: Validation of Antioxidant and Vasculoprotective Activities

Antioxidants ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 787 ◽  
Author(s):  
María Jesús Pérez de Vega ◽  
Silvia Moreno-Fernández ◽  
Gloria María Pontes-Quero ◽  
María González-Amor ◽  
Blanca Vázquez-Lasa ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Radical Scavenging Activity ◽  
Antioxidant Properties ◽  
Radical Scavenging ◽  
Antioxidant Compounds ◽  
Therapeutic Effects ◽  
Protective Effects ◽  
Therapeutic Benefits ◽  
Anti Inflammatory

Antioxidant compounds, including polyphenols, have therapeutic effects because of their anti-inflammatory, antihypertensive, antithrombotic and antiproliferative properties. They play important roles in protecting the cardiovascular and neurological systems, by having preventive or protective effects against free radicals produced by either normal or pathological metabolism in such systems. For instance, resveratrol, a well-known potent antioxidant, has a counteracting effect on the excess of reactive oxygen species (ROS) and has a number of therapeutic benefits, like anti-inflammatory, anti-cancer and cardioprotective activities. Based on previous work from our group, and on the most frequent OH substitutions of natural polyphenols, we designed two series of synthetically accessible bis-polyhydroxyphenyl derivatives, separated by amide or urea linkers. These compounds exhibit high antioxidant ability (oxygen radical absorbance capacity (ORAC) assay) and interesting radical scavenging activity (RSA) values (2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and α,α-diphenyl-β-picrylhydrazyl (DPPH) tests). Some of the best polyphenols were evaluated in two biological systems, endothelial cells (in vitro) and whole aorta (ex vivo), highly susceptible for the deleterious effects of prooxidants under different inflammatory conditions, showing protection against oxidative stress induced by inflammatory stimuli relevant in cardiovascular diseases, i.e., Angiotensin II and IL-1β. Selected compounds also showed strong in vivo antioxidant properties when evaluated in the model organism Saccharomyces cerevisiae.

scholarly journals Methyl lucidone exhibits neuroprotective effects on glutamate-induced oxidative stress in HT-22 cells via Nrf-2/HO-1 signaling

2019 ◽  
Vol 62 (1) ◽  
Author(s):  
Jee-Yun Park ◽  
Khulan Amarsanaa ◽  
Yanji Cui ◽  
Ji-Hyung Lee ◽  
Jinji Wu ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Nuclear Translocation ◽  
Radical Scavenging Activity ◽  
Neuronal Cell Death ◽  
Radical Scavenging ◽  
Neuronal Cell ◽  
Heme Oxygenase 1 ◽  
Related Factor ◽  
Neuroprotective Effects ◽  
Akt Phosphorylation

Abstract Oxidative stress causes neuronal cell death in various neurodegenerative diseases, such as Alzheimer’s disease, ischemia, and Parkinson’s disease. Therefore, reducing intracellular reactive oxygen species (ROS) has been evaluated as an effective treatment strategy for neurodegenerative disorders. Methyl lucidone (MLC) extracted from Lindera erythrocarpa Makino (Lauraceae) has been previously reported to exhibit microglial-mediated neuroprotective effects via inhibiting neuroinflammation. However, the antioxidant effects of MLC are still unclear. The aim of this study was to determine the neuroprotective mechanism of MLC in HT-22 neurons against oxidative stress induced by glutamate. In results, the pretreatment of MLC significantly enhanced the viability of HT-22 cells under glutamate-induced oxidative conditions, suggesting that MLC has a neuronal mechanism to protect neurons without microglial regulation. Also, the glutamate effect to increase ROS production was effectively blocked by MLC without any free radical scavenging activity. To induce this antioxidant effect, MLC upregulated the expression of heme oxygenase 1 (HO-1) and nuclear translocation of nuclear factor-E2-related factor 2 (Nrf-2), known as an intracellular antioxidant enzyme, and its transcription factor. Additionally, Akt phosphorylation regulating Nrf-2 was confirmed to be involved in the neuroprotective signaling activated by MLC. These results indicate that MLC may play a role as an antioxidant agent to inhibit neurodegenerative processes via activating antioxidant signaling pathways that include Nrf-2 and phosphatidylinositol 3-kinase (PI3K).

Synthesis, Characterization, Antimicrobial and Antioxidant Potential of Diazenyl Chalcones

2018 ◽  
Vol 18 (10) ◽  
pp. 844-856 ◽  
Author(s):  
Harmeet Kaur ◽  
Balasubramanian Narasimhan
Keyword(s):  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Antioxidant Potential ◽  
Dilution Method ◽  
Dpph Assay ◽  
Antimicrobial Potential ◽  
Structural Conformation ◽  
Uv Visible ◽  
Tube Dilution Method

A series of diazenyl chalcones was prepared by base catalyzed Claisen-Schmidt condensation of synthesized hydroxy substituted acetophenone azo dye with various substituted aromatic/ heteroaromatic aldehydes. The structural conformation of synthesized chalcones was done by a number of physicochemical and spectral means like FTIR, UV-visible, mass, NMR spectroscopy and CHNS/O analysis. These diazenyl chalcones were assessed for their in vitro antimicrobial potential against several Gram-negative, Gram-positive bacterial and fungal strains by serial tube dilution method. The fluconazole and cefadroxil were used as standard drugs. The target compounds were also evaluated for their antioxidant potential by DPPH assay. (2E)-3-(2,4-Dichlorophenyl)-1-(4-((2,6- dihydroxyphenyl)diazenyl)phenyl)prop-2-en-1-one (C-7) had shown very good antimicrobial potential with MIC ranges from 3.79 to 15.76 μg/ml against most of the tested microorganisms. Most of the synthesized diazenyl chalcones were found to be active against B. subtilis. The (2E)-1-(5-((2-Chloro- 4-nitrophenyl)diazenyl)-2-hydroxyphenyl)-3-(2-hydroxynaphthalen-1-yl)prop-2-en-1-one (C-10) had shown high free radical-scavenging activity when compared with the ascorbic acid as the reference antioxidant.

α-Glucosidase Inhibition, Antioxidant and Docking Studies of Hydroxycoumarins and their Mono and Bis O-alkylated/acetylated Analogs

2018 ◽  
Vol 15 (2) ◽  
pp. 127-135 ◽  
Author(s):  
Parvesh Singh ◽  
Nomandla Ngcoya ◽  
Ramgopal Mopuri ◽  
Nagaraju Kerru ◽  
Neha Manhas ◽  
...  
Keyword(s):  
In Silico ◽  
Biological Activities ◽  
Wide Spectrum ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Catalytic Site ◽  
Docking Simulations ◽  
In Silico Docking ◽  
Anti Oxidant

Background: Diabetes Mellitus (DM) is a complex metabolic disease illustrated by abnormally high levels of plasma glucose or hyperglycaemia. Accordingly, several α-glucosidase inhibitors have been developed for the treatment of diabetes and other degenerative disorders. While, a coumarin ring has the privilege to represent numerous natural and synthetic compounds with a wide spectrum of biological activities e.g. anti-cancer, anti-HIV, anti-viral, anti-malarial, anti-microbial, anti-convulsant, anti-hypertensive properties. Besides this, coumarins have also shown potential to inhibit α-glucosidase leading to a generation of new promising antidiabetic agents. However, the testing of O-substituted coumarins for α-glucosidase inhibition has evaded the attention of medicinal chemists. Methods: For O-alkylation/acetylation reactions, the hydroxyl coumarins (A-B) initially activated by K2CO3 in dry DMF were reacted with variedly substituted haloalkanes at room temperature under nitrogen. The synthesized compounds were tested for their α-glucosidase (from Saccharomyces cerevisiae) inhibitory activity and anti-oxidant activity using DPPH radical scavenging activity. In silico docking simulations were conducted using CDocker module in DS (Accelrys) to explore the binding modes of the representative compounds in the catalytic site of α-glucosidase. Results: All the coumarin analogues (A1, B1, A2-A10, B2-B8) including their precursors (A-B) were evaluated for their in vitro α-glucosidase inhibition using acarbose as a standard inhibitor. All the mono O-alkylated coumarins (except A1) showed significant (p <0.05) α-glucosidase inhibition relative to the hydroxyl coumarin (A) with IC50 values ranging between 11.084±0.117 to 145.24± 29.22 µg/mL. Compound 7-(benzyloxy)-4, 5-dimethyl-2H-chromen-2-one (A9) bearing a benzyl group (Ph-CH2-) at position 7 showed a remarkable (p <0.05) increase in the activity (IC50 = 11.084±0.117 µg/mL), almost four-fold more than acarbose (IC50 = 40.578±5.999 µg/mL). The introduction of –NO2 group dramatically improved the anti-oxidant activity of coumarin, while the O-alkylation/acetylation decreased the activity. Conclusion: The present study describes the synthesis of functionalized coumarins and their evaluation for α-glucosidase inhibition and antioxidant activity under in vitro conditions. Based on IC50 data, the mono O-alkylated coumarins were observed to be stronger inhibitors of α-glucosidase with respect to their bis O-alkylated analogues. Coumarin (A9) bearing O-benzyloxy group displayed the strongest α-glucosidase inhibition, even higher than the standard inhibitor acarbose. The coumarin (A10) bearing –NO2 group showed the highest anti-oxidant activity amongst the synthesized compounds, almost comparable to the ascorbic acid. Finally, in silico docking simulations revealed the role of hydrogen bonding and hydrophobic forces in locking the compounds in catalytic site of α-glucosidase.

Curcumin-based antioxidant and glycohydrolase inhibitor compounds: Synthesis and in vitro appraisal of the dual activity against diabetes

2020 ◽  
Vol 16 ◽  
Author(s):  
Sajjad Esmaeili ◽  
Nazanin Ghobadi ◽  
Donya Nazari ◽  
Alireza Pourhossein ◽  
Hassan Rasouli ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Enzyme Inhibitor ◽  
Radical Scavenging Activity ◽  
Curcuma Longa ◽  
Radical Scavenging ◽  
Reducing Power ◽  
Inhibitory Effect ◽  
Curcumin Derivatives ◽  
Reducing Power Assay

Background: Curcumin, as the substantial constituent of the turmeric plant (Curcuma longa), plays a significant role in the prevention of various diseases, including diabetes. It possesses ideal structure features as enzyme inhibitor, including a flexible backbone, hydrophobic nature, and several available hydrogen bond (H-bond) donors and acceptors. Objective: The present study aimed at synthesizing several novel curcumin derivatives and further evaluation of these compounds for possible antioxidant and anti-diabetic properties along with inhibitory effect against two carbohydrate-hydrolyzing enzymes, α-amylase and α-glucosidase, as these enzymes are therapeutic targets for attenuation of postprandial hyperglycemia. Methods: Therefore, curcumin-based pyrido[2,3-d]pyrimidine derivatives were synthesized and identified using an instrumental technique like NMR spectroscopy and then screened for antioxidant and enzyme inhibitory potential. Total antioxidant activity, reducing power assay and 1,1-diphenyl-2-picrylhydrazyl (DPPH• ) radical scavenging activity were done to appraisal the antioxidant potential of these compounds in vitro. Results: Compounds L6-L9 showed higher antioxidant activity while L4, L9, L12 and especially L8 exhibited the best selectivity index (lowest α-amylase/α-glucosidase inhibition ratio). Conclusion: These antioxidant inhibitors may be potential anti-diabetic drugs, not only to reduce glycemic index but also to limit the activity of the major reactive oxygen species (ROS) producing pathways.

scholarly journals Therapeutic Effects of Dipterocarpus tuberculatus with High Antioxidative Activity Against UV-Induced Photoaging of NHDF Cells and Nude Mice

Antioxidants ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 791
Author(s):  
Su Jin Lee ◽  
Ji Eun Kim ◽  
Yun Ju Choi ◽  
Jeong Eun Gong ◽  
So Hae Park ◽  
...  
Keyword(s):  
Nude Mice ◽  
Dermal Fibroblast ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Inflammasome Activation ◽  
Therapeutic Effects ◽  
Asiatic Acid ◽  
Active Components ◽  
Normal Human Dermal Fibroblast ◽  
Sod Activity

To investigate the therapeutic effects of methanol extracts of Dipterocarpus tuberculatus Roxb. (MED) against UV-induced photoaging, we assessed for alterations in the antioxidant activity, anti-apoptotic effects, ECM modulation, skin appearances, and anti-inflammatory response in normal human dermal fibroblast (NHDF) cells and nude mice orally treated with MED. High levels of tannin content and high free radical scavenging activity to DPPH were determined in MED, while seven active components, namely, gallic acid, bergenin, ellagic acid, ε-viniferin, asiatic acid, oleanolic acid, and 2α-hydroxyursolic acid, were identified using LC–MS analyses. UV-induced alterations in the NO concentration, SOD activity, and Nrf2 expression were remarkably recovered in MED-treated NHDF cells. Moreover, the decreased number of apoptotic cells and G2/M phase arrest were observed in the UV + MED-treated groups. Similar recoveries were detected for β-galactosidase, MMP-2/9 expression, and intracellular elastase activity. Furthermore, MED treatment induced suppression of the COX-2-induced iNOS mediated pathway, expression of inflammatory cytokines, and inflammasome activation in UV-radiated NHDF cells. The anti-photoaging effects observed in NHDF cells were subsequently evaluated and validated in UV + MED-treated nude mice through skin phenotypes and histopathological structure analyses. Taken together, these results indicate that MED exerts therapeutic effects against UV-induced photoaging and has the potential for future development as a treatment for photoaging.

scholarly journals Inhibitory Effect of Antidesma bunius Fruit Extract on Carbohydrate Digestive Enzymes Activity and Protein Glycation In Vitro

Antioxidants ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 32
Author(s):  
Pattamaporn Aksornchu ◽  
Netima Chamnansilpa ◽  
Sirichai Adisakwattana ◽  
Thavaree Thilavech ◽  
Charoonsri Choosak ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Radical Scavenging Activity ◽  
Digestive Enzyme ◽  
Radical Scavenging ◽  
Protein Glycation ◽  
Trolox Equivalent Antioxidant Capacity ◽  
Fruit Extract ◽  
Antioxidant Power ◽  
Ic50 Values

Antidesma bunius (L.) spreng (Mamao) is widely distributed in Northeastern Thailand. Antidesma bunius has been reported to contain anthocyanins, which possess antioxidant and antihypertensive actions. However, the antidiabetic and antiglycation activity of Antidesma bunius fruit extract has not yet been reported. In this study, we investigated the inhibitory activity of anthocyanin-enriched fraction of Antidesma bunius fruit extract (ABE) against pancreatic α-amylase, intestinal α-glucosidase (maltase and sucrase), protein glycation, as well as antioxidant activity. A liquid chromatography-tandem mass spectrometry (LC-MS/MS) chromatogram revealed that ABE contained phytochemical compounds such as cyanidin-3-glucoside, delphinidin-3-glucoside, ellagic acid, and myricetin-3-galactoside. ABE inhibited intestinal maltase and sucrase activity with the IC50 values of 0.76 ± 0.02 mg/mL and 1.33 ± 0.03 mg/mL, respectively. Furthermore, ABE (0.25 mg/mL) reduced the formation of fluorescent AGEs and the level of Nε-carboxymethyllysine (Nε-CML) in fructose and glucose-induced protein glycation during four weeks of incubation. During the glycation process, the protein carbonyl and β-amyloid cross structure were decreased by ABE (0.25 mg/mL). In addition, ABE exhibited antioxidant activity through DPPH radical scavenging activity and Trolox equivalent antioxidant capacity (TEAC) with the IC50 values 15.84 ± 0.06 µg/mL and 166.1 ± 2.40 µg/mL, respectively. Meanwhile, ferric reducing antioxidant power (FRAP) showed an EC50 value of 182.22 ± 0.64 µg/mL. The findings suggest that ABE may be a promising agent for inhibiting carbohydrate digestive enzyme activity, reducing monosaccharide-induced protein glycation, and antioxidant activity.

scholarly journals Enhancement of Antioxidant and Hydrophobic Properties of Alginate via Aromatic Derivatization: Preparation, Characterization, and Evaluation

Polymers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2575
Author(s):  
Smaher M. Elbayomi ◽  
Haili Wang ◽  
Tamer M. Tamer ◽  
Yezi You
Keyword(s):  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Hydroxyl Group ◽  
Hydroxyl Groups ◽  
Gravimetric Analysis ◽  
Scanning Calorimetry ◽  
Benzoyl Group ◽  
Antioxidant Evaluation ◽  
Thermo Stability

The preparation of bioactive polymeric molecules requires the attention of scientists as it has a potential function in biomedical applications. In the current study, functional substitution of alginate with a benzoyl group was prepared via coupling its hydroxyl group with benzoyl chloride. Fourier transform infrared spectroscopy indicated the characteristic peaks of aromatic C=C in alginate derivative at 1431 cm−1. HNMR analysis demonstrated the aromatic protons at 7.5 ppm assigned to benzoyl groups attached to alginate hydroxyl groups. Wetting analysis showed a decrease in hydrophilicity in the new alginate derivative. Differential scanning calorimetry and thermal gravimetric analysis showed that the designed aromatic alginate derivative demonstrated higher thermo-stability than alginates. The aromatic alginate derivative displayed high anti-inflammatory properties compared to alginate. Finally, the in vitro antioxidant evaluation of the aromatic alginate derivative showed a significant increase in free radical scavenging activity compared to neat alginate against DPPH (2,2-diphenyll-picrylhydrazyl) and ABTS free radicals. The obtained results proposed that the new alginate derivative could be employed for gene and drug delivery applications.

Sign in / Sign up

Export Citation Format

Share Document