International Journal of Molecular Sciences

Research

Jump to: Review

396 KiB

Open AccessArticle

Extracts of Phenolic Compounds from Seeds of Three Wild Grapevines—Comparison of Their Antioxidant Activities and the Content of Phenolic Compounds

by Stanisław Weidner, Anna Powałka, Magdalena Karamać and Ryszard Amarowicz

Int. J. Mol. Sci. 2012, 13(3), 3444-3457; https://doi.org/10.3390/ijms13033444 - 13 Mar 2012

Cited by 30 | Viewed by 7651

Abstract

Phenolic compounds were extracted from three wild grapevine species: Vitis californica, V. riparia and V. amurensis seeds using 80% methanol or 80% acetone. The total content of phenolic compounds was determined utilizing the Folin-Ciocalteu’s phenol reagent while the content of tannins was [...] Read more.

Phenolic compounds were extracted from three wild grapevine species: Vitis californica, V. riparia and V. amurensis seeds using 80% methanol or 80% acetone. The total content of phenolic compounds was determined utilizing the Folin-Ciocalteu’s phenol reagent while the content of tannins was assayed with the vanillin and BSA precipitation methods. Additionally, the DPPHfree radical scavenging activity and the reduction power of the extracts were measured. The RP-HPLC method was applied to identify the phenolic compounds in the extracts, such as phenolic acids and catechins. The seeds contained large amounts of tannins, catechins and gallic acid and observable quantities of p-coumaric acid. The total content of phenolic compounds and tannins was similar in the extracts from V. californica and V. riparia seeds. However, the total content of total phenolic compounds and tannins in the extracts from V. californica and V. riperia seeds were about two-fold higher than that in the extracts from V. amurensis seeds. Extracts from seeds of the American species (V. californica and V. riparia) contained similarly high concentrations of tannins, whereas extracts from seeds of V. amurensis had approximately half that amount of these compounds. The content of catechin and epicatechin was similar in all extracts. The highest DPPH^• anti-radical scavenging activity was observed in the acetonic and methanolic extracts of V. californica and V. riparia seeds—while the acetonic extract from the V. californica seeds was the strongest reducing agent. Full article

(This article belongs to the Special Issue Antioxidants)

► Show Figures

150 KiB

Open AccessArticle

Antioxidant Activity of Mulberry Fruit Extracts

by Muhammad Arfan, Rasool Khan, Anna Rybarczyk and Ryszard Amarowicz

Int. J. Mol. Sci. 2012, 13(2), 2472-2480; https://doi.org/10.3390/ijms13022472 - 22 Feb 2012

Cited by 103 | Viewed by 13334

Abstract

Phenolic compounds were extracted from the fruits of Morus nigra and Morus alba using methanol and acetone. The sugar-free extracts (SFEs) were prepared using Amberlite XAD-16 column chromatography. All of the SFEs exhibited antioxidant potential as determined by ABTS (0.75–1.25 mmol Trolox/g), DPPH [...] Read more.

Phenolic compounds were extracted from the fruits of Morus nigra and Morus alba using methanol and acetone. The sugar-free extracts (SFEs) were prepared using Amberlite XAD-16 column chromatography. All of the SFEs exhibited antioxidant potential as determined by ABTS (0.75–1.25 mmol Trolox/g), DPPH (2,2-diphenyl-1-picrylhydrazyl) (EC₅₀ from 48 μg/mL to 79 μg/mL), and reducing power assays. However, a stronger activity was noted for the SFEs obtained from Morus nigra fruits. These extracts also possessed the highest contents of total phenolics: 164 mg/g (methanolic SFE) and 173 mg/g (acetonic SFE). The presence of phenolic acids and flavonoids in the extracts was confirmed using HPLC method and chlorogenic acid and rutin were found as the dominant phenolic constituents in the SFEs. Full article

(This article belongs to the Special Issue Antioxidants)

► Show Figures

Graphical abstract

725 KiB

Open AccessArticle

Emodin Prevents Intrahepatic Fat Accumulation, Inflammation and Redox Status Imbalance During Diet-Induced Hepatosteatosis in Rats

by Anna Alisi, Anna Pastore, Sara Ceccarelli, Nadia Panera, Daniela Gnani, Giovannella Bruscalupi, Mara Massimi, Giulia Tozzi, Fiorella Piemonte and Valerio Nobili

Int. J. Mol. Sci. 2012, 13(2), 2276-2289; https://doi.org/10.3390/ijms13022276 - 20 Feb 2012

Cited by 54 | Viewed by 8584

Abstract

High-fat and/or high-carbohydrate diets may predispose to several metabolic disturbances including liver fatty infiltration (hepatosteatosis) or be associated with necro-inflammation and fibrosis (steatohepatitis). Several studies have emphasized the hepatoprotective effect of some natural agents. In this study, we investigated the potential therapeutic effects [...] Read more.

High-fat and/or high-carbohydrate diets may predispose to several metabolic disturbances including liver fatty infiltration (hepatosteatosis) or be associated with necro-inflammation and fibrosis (steatohepatitis). Several studies have emphasized the hepatoprotective effect of some natural agents. In this study, we investigated the potential therapeutic effects of the treatment with emodin, an anthraquinone derivative with anti-oxidant and anti-cancer abilities, in rats developing diet-induced hepatosteatosis and steatohepatitis. Sprague-Dawley rats were fed a standard diet (SD) for 15 weeks, or a high-fat/high-fructose diet (HFD/HF). After 5 weeks, emodin was added to the drinking water of some of the SD and HFD/HF rats. The experiment ended after an additional 10 weeks. Emodin-treated HFD/HF rats were protected from hepatosteatosis and metabolic derangements usually observed in HFD/HF animals. Furthermore, emodin exerted anti-inflammatory activity by inhibiting the HFD/HF-induced increase of tumor necrosis factor (TNF)-α. Emodin also affected the hepatocytes glutathione homeostasis and levels of the HFD/HF-induced increase of glutathionylated/phosphorylated phosphatase and tensin homolog (PTEN). In conclusion, we demonstrated that a natural agent such as emodin can prevent hepatosteatosis, preserving liver from pro-inflammatory and pro-oxidant damage caused by HFD/HF diet. These findings are promising, proposing emodin as a possible hindrance to progression of hepatosteatosis into steatohepatitis. Full article

(This article belongs to the Special Issue Antioxidants)

► Show Figures

260 KiB

Open AccessArticle

Lipid Peroxidative Damage on Cisplatin Exposure and Alterations in Antioxidant Defense System in Rat Kidneys: A Possible Protective Effect of Selenium

by Branka I. Ognjanović, Nataša Z. Djordjević, Miloš M. Matić, Jasmina M. Obradović, Jelena M. Mladenović, Andraš Š. Štajn and Zorica S. Saičić

Int. J. Mol. Sci. 2012, 13(2), 1790-1803; https://doi.org/10.3390/ijms13021790 - 8 Feb 2012

Cited by 106 | Viewed by 8977

Abstract

Cisplatin (Cis-diamminedichloroplatinum II, CP) is an important chemotherapeutic agent, useful in the treatment of several cancers, but with several side effects such as nephrotoxicity. The present study investigated the possible protective effect of selenium (Se) against CP-induced oxidative stress in the [...] Read more.

Cisplatin (Cis-diamminedichloroplatinum II, CP) is an important chemotherapeutic agent, useful in the treatment of several cancers, but with several side effects such as nephrotoxicity. The present study investigated the possible protective effect of selenium (Se) against CP-induced oxidative stress in the rat kidneys. Male Wistar albino rats were injected with a single dose of cisplatin (7 mg CP/kg b.m., i.p.) and selenium (6 mg Se/kg b.m, as Na₂SeO₃, i.p.), alone or in combination. The obtained results showed that CP increased lipid peroxidation (LPO) and decreased reduced glutathione (GSH) concentrations, suggesting the CP-induced oxidative stress, while Se treatment reversed this change to control values. Acute intoxication of rats with CP was followed by statistically significant decreased activity of antioxidant defense enzymes: superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), glutathione reductase (GR) and glutathione-S-transferase (GST). Treatment with Se reversed CP-induced alterations of antioxidant defense enzyme activities and significantly prevented the CP-induced kidney damage. Full article

(This article belongs to the Special Issue Antioxidants)

► Show Figures

449 KiB

Open AccessArticle

10-Shogaol, an Antioxidant from Zingiber officinale for Skin Cell Proliferation and Migration Enhancer

by Chung-Yi Chen, Kuo-Chen Cheng, Andy Y Chang, Ying-Ting Lin, You-Cheng Hseu and Hui-Min Wang

Int. J. Mol. Sci. 2012, 13(2), 1762-1777; https://doi.org/10.3390/ijms13021762 - 8 Feb 2012

Cited by 53 | Viewed by 9762

Abstract

In this work, one of Zingiber officinale components, 10-shogaol, was tested with 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging, metal chelating ability, and reducing power to show antioxidant activity. 10-Shogaol promoted human normal epidermal keratinocytes and dermal fibroblasts cell growths. 10-Shogaol enhanced growth factor production in [...] Read more.

In this work, one of Zingiber officinale components, 10-shogaol, was tested with 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging, metal chelating ability, and reducing power to show antioxidant activity. 10-Shogaol promoted human normal epidermal keratinocytes and dermal fibroblasts cell growths. 10-Shogaol enhanced growth factor production in transforming growth factor-β (TGF-β), platelet derived growth factor-αβ (PDGF-αβ) and vascular endothelial growth factors (VEGF) of both cells. In the in vitro wound healing assay for 12 or 24 h, with 10-shogaol, the fibroblasts and keratinocytes migrated more rapidly than the vehicle control group. Thus, this study substantiates the target compound, 10-shogaol, as an antioxidant for human skin cell growth and a migration enhancer with potential to be a novel wound repair agent. Full article

(This article belongs to the Special Issue Antioxidants)

► Show Figures

239 KiB

Open AccessArticle

Coenzyme Q Metabolism Is Disturbed in High Fat Diet-Induced Non Alcoholic Fatty Liver Disease in Rats

by Elena Bravo, Simonetta Palleschi, Barbara Rossi, Mariarosaria Napolitano, Luca Tiano, Emanuela D’Amore and Kathleen M Botham

Int. J. Mol. Sci. 2012, 13(2), 1644-1657; https://doi.org/10.3390/ijms13021644 - 2 Feb 2012

Cited by 12 | Viewed by 7555

Abstract

Oxidative stress is believed to be a major contributory factor in the development of non alcoholic fatty liver disease (NAFLD), the most common liver disorder worldwide. In this study, the effects of high fat diet-induced NAFLD on Coenzyme Q (CoQ) metabolism and plasma [...] Read more.

Oxidative stress is believed to be a major contributory factor in the development of non alcoholic fatty liver disease (NAFLD), the most common liver disorder worldwide. In this study, the effects of high fat diet-induced NAFLD on Coenzyme Q (CoQ) metabolism and plasma oxidative stress markers in rats were investigated. Rats were fed a standard low fat diet (control) or a high fat diet (57% metabolizable energy as fat) for 18 weeks. The concentrations of total (reduced + oxidized) CoQ9 were increased by > 2 fold in the plasma of animals fed the high fat diet, while those of total CoQ10 were unchanged. Reduced CoQ levels were raised, but oxidized CoQ levels were not, thus the proportion in the reduced form was increased by about 75%. A higher percentage of plasma CoQ9 as compared to CoQ10 was in the reduced form in both control and high fat fed rats. Plasma protein thiol (SH) levels were decreased in the high fat-fed rats as compared to the control group, but concentrations of lipid hydroperoxides and low density lipoprotein (LDL) conjugated dienes were unchanged. These results indicate that high fat diet-induced NAFLD in rats is associated with altered CoQ metabolism and increased protein, but not lipid, oxidative stress. Full article

(This article belongs to the Special Issue Antioxidants)

► Show Figures

112 KiB

Open AccessArticle

Effect of Byrsonima crassa and Phenolic Constituents on Helicobacter pylori-Induced Neutrophils Oxidative Burst

by Cibele Bonacorsi, Maria Stella G. Raddi, Luiz Marcos Da Fonseca, Miriam Sannomiya and Wagner Vilegas

Int. J. Mol. Sci. 2012, 13(1), 133-141; https://doi.org/10.3390/ijms13010133 - 23 Dec 2011

Cited by 16 | Viewed by 7968

Abstract

Byrsonima crassa Niedenzu (Malpighiaceae) is used in Brazilian folk medicine for the treatment of diseases related mainly to gastric ulcers. In a previous study, our group described the gastric protective effect of the methanolic extract from the leaves of B. crassa. The [...] Read more.

Byrsonima crassa Niedenzu (Malpighiaceae) is used in Brazilian folk medicine for the treatment of diseases related mainly to gastric ulcers. In a previous study, our group described the gastric protective effect of the methanolic extract from the leaves of B. crassa. The present study was carried out to investigate the effects of methanolic extract and its phenolic compounds on the respiratory burst of neutrophils stimulated by H. pylori using a luminol-based chemiluminescence assay as well as their anti-H. pylori activity. The suppressive activity on oxidative burst of H. pylori-stimulated neutrophils was in the order of methyl gallate > (+)-catechin > methanol extract > quercetin 3-O-α-l-arabinopyranoside > quercetin 3-O-β-d-galactopyranoside > amentoflavone. Methyl gallate, compound that induced the highest suppressive activity with IC₅₀ value of 3.4 µg/mL, did not show anti-H. pylori activity. B. crassa could be considered as a potential source of natural antioxidant in gastric ulcers by attenuating the effects on the damage to gastric mucosa caused by neutrophil generated reactive oxygen species, even when H. pylori displays its evasion mechanisms. Full article

(This article belongs to the Special Issue Antioxidants)

719 KiB

Open AccessArticle

Anti-UVC Irradiation and Metal Chelation Properties of 6-Benzoyl-5,7-dihydroxy-4-phenyl-chromen-2-one: An Implications for Anti-Cataract Agent

by Jiahn-Haur Liao, Tzu-Hua Wu, Feng-Lin Hsu, Yi-Shiang Huang, Po-Hung Chiang, Zih-You Huang, Chi-Hsien Huang, Shih-Hsiung Wu and Mei-Hsiang Lin

Int. J. Mol. Sci. 2011, 12(10), 7059-7076; https://doi.org/10.3390/ijms12107059 - 21 Oct 2011

Cited by 5 | Viewed by 8935

Abstract

Coumarin derivative 1, 5,7-dihydroxy-6-(3-methyl-1-butyryl)-4-phenyl-chromen-2-one, has been reported to possess radical scavenging activity and DNA protection. We have synthesized a series of coumarins with structural modifications at positions C4, C5, C6 and C7 and evaluated them for their anti-UVC properties. Coumarin 7, 6-benzoyl-5,6-dihydroxy-4-phenyl-chromen-2-one, was [...] Read more.

Coumarin derivative 1, 5,7-dihydroxy-6-(3-methyl-1-butyryl)-4-phenyl-chromen-2-one, has been reported to possess radical scavenging activity and DNA protection. We have synthesized a series of coumarins with structural modifications at positions C4, C5, C6 and C7 and evaluated them for their anti-UVC properties. Coumarin 7, 6-benzoyl-5,6-dihydroxy-4-phenyl-chromen-2-one, was found to have the most potent activity in protecting porcine γ-crystallin against UVC insults. Results of fluorescence assays indicated that compound 7 was capable of decreasing the loss of intensity while lens crystallins and DNA PUC19 were irradiated with UVC. Presence of compound 7 decreased hydroxyl radical levels determined by probe 1b and the free iron concentrations determined by Ferrozine reagent. The chelation assay showed that compound 7 was chelated to metal via 6-CO and 5-OH on the benzopyrone ring. The observed protective effects of compound 7 towards crystallins from insults of UVC and free radicals may be due to its iron-chelating activity and its peak absorption at 254 nm. Full article

(This article belongs to the Special Issue Antioxidants)

► Show Figures

Graphical abstract

268 KiB

Open AccessArticle

N-Acetylcysteine Reduces Markers of Differentiation in 3T3-L1 Adipocytes

by Pablo Calzadilla, Daiana Sapochnik, Soledad Cosentino, Virginia Diz, Lelia Dicelio, Juan Carlos Calvo and Liliana N. Guerra

Int. J. Mol. Sci. 2011, 12(10), 6936-6951; https://doi.org/10.3390/ijms12106936 - 19 Oct 2011

Cited by 84 | Viewed by 8915

Abstract

Oxidative stress plays a critical role in the pathogenesis of diabetes, hypertension and atherosclerosis. Some authors reported that fat accumulation correlates to systemic oxidative stress in humans and mice, but the relationship of lipid production and oxidative metabolism is still unclear. In our [...] Read more.

Oxidative stress plays a critical role in the pathogenesis of diabetes, hypertension and atherosclerosis. Some authors reported that fat accumulation correlates to systemic oxidative stress in humans and mice, but the relationship of lipid production and oxidative metabolism is still unclear. In our laboratory we used 3T3-L1 preadipocytes, which are able to differentiate into mature adipocytes and accumulate lipids, as obesity model. We showed that intracellular reactive oxygen species (ROS) and antioxidant enzymes superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities increased in parallel with fat accumulation. Meanwhile N-acetylcysteine (NAC), a well known antioxidant and Glutathione (GSH) precursor, inhibited ROS levels as well as fat accumulation in a concentration-dependent manner. NAC also inhibited both adipogenic transcription factors CCAAT/enhancer binding protein beta (C/EBP β) and peroxisomal proliferator activated receptor gamma (PPAR γ) expression; we suggested that intracellular GSH content could be responsible for these effects. Full article

(This article belongs to the Special Issue Antioxidants)

► Show Figures

575 KiB

Open AccessArticle

Antioxidant Properties of the Edible Basidiomycete Armillaria mellea in Submerged Cultures

by Ming-Yeou Lung and Yu-Cheng Chang

Int. J. Mol. Sci. 2011, 12(10), 6367-6384; https://doi.org/10.3390/ijms12106367 - 26 Sep 2011

Cited by 36 | Viewed by 8779

Abstract

Antioxidant components, ascorbic acid, total flavonoids and total phenols are produced effectively by Armillaria mellea submerged cultures. Dried mycelia and mycelia-free broths obtained by A. mellea submerged cultures are extracted with methanol and hot water and investigated for antioxidant properties. Methanolic extracts from [...] Read more.

Antioxidant components, ascorbic acid, total flavonoids and total phenols are produced effectively by Armillaria mellea submerged cultures. Dried mycelia and mycelia-free broths obtained by A. mellea submerged cultures are extracted with methanol and hot water and investigated for antioxidant properties. Methanolic extracts from dried mycelia (MEM) and mycelia-free broth (MEB) and hot water extracts from dried mycelia (HWEM) by A. mellea submerged cultures show good antioxidant properties as evidenced by low EC₅₀ values (< 10 mg/mL). Total flavonoid is mainly found in hot water extracts; however, total phenol is rich in methanol and hot water extracts from mycelia. Ascorbic acid and total phenol contents are well correlated with the reducing power and the scavenging effect on superoxide anions. Total flavonoid content is dependent on the antioxidant activity and the chelating effect on ferrous ions. Total antioxidant component contents are closely related to the antioxidant activity and the scavenging superoxide anion ability. Results confirm that extracts with good antioxidant properties from fermenting products by A. mellea are potential good substitutes for synthetic antioxidants and can be applied to antioxidant-related functional food and pharmaceutical industries. Full article

(This article belongs to the Special Issue Antioxidants)

► Show Figures

729 KiB

Open AccessArticle

Different Impacts of Cardiovascular Risk Factors on Oxidative Stress

by Maria L. Mansego, Josep Redon, Sergio Martinez-Hervas, Jose T. Real, Fernando Martinez, Sebastian Blesa, Veronica Gonzalez-Albert, Guillermo T. Saez, Rafael Carmena and Felipe J. Chaves

Int. J. Mol. Sci. 2011, 12(9), 6146-6163; https://doi.org/10.3390/ijms12096146 - 20 Sep 2011

Cited by 19 | Viewed by 9012

Abstract

The objective of the study was to evaluate oxidative stress (OS) status in subjects with different cardiovascular risk factors. With this in mind, we have studied three models of high cardiovascular risk: hypertension (HT) with and without metabolic syndrome, familial hypercholesterolemia (FH) and [...] Read more.

The objective of the study was to evaluate oxidative stress (OS) status in subjects with different cardiovascular risk factors. With this in mind, we have studied three models of high cardiovascular risk: hypertension (HT) with and without metabolic syndrome, familial hypercholesterolemia (FH) and familial combined hyperlipidemia (FCH) with and without insulin resistance. Oxidative stress markers (oxidized/reduced glutathione ratio, 8-oxo-deoxyguanosine and malondialdehide) together with the activity of antioxidant enzyme triad (superoxide dismutase, catalase, glutathione peroxidase) and activation of both pro-oxidant enzyme (NAPDH oxidase components) and AGTR1 genes, as well as antioxidant enzyme genes (CuZn-SOD, CAT, GPX1, GSR, GSS and TXN) were measured in mononuclear cells of controls (n = 20) and patients (n = 90) by assessing mRNA levels. Activity of some of these antioxidant enzymes was also tested. An increase in OS and pro-oxidant gene mRNA values was observed in patients compared to controls. The hypertensive group showed not only the highest OS values, but also the highest pro-oxidant activation compared to those observed in the other groups. In addition, in HT a significantly reduced antioxidant activity and mRNA induction of antioxidant genes were found when compared to controls and the other groups. In FH and FCH, the activation of pro-oxidant enzymes was also higher and antioxidant ones lower than in the control group, although it did not reach the values obtained in hypertensives. The thioredoxin system was more activated in patients as compared to controls, and the highest levels were in hypertensives. The increased oxidative status in the presence of cardiovascular risk factors is a consequence of both the activation of pro-oxidant mechanisms and the reduction of the antioxidant ones. The altered response of the main cytoplasmic antioxidant systems largely contributes to OS despite the apparent attempt of the thioredoxin system to control it. Full article

(This article belongs to the Special Issue Antioxidants)

► Show Figures

477 KiB

Open AccessArticle

Identification of a Protein with Antioxidant Activity that is Important for the Protection against Beer Ageing

by Ming J. Wu, Frank M. Clarke, Peter J. Rogers, Paul Young, Narelle Sales, Patrick J. O’Doherty and Vincent J. Higgins

Int. J. Mol. Sci. 2011, 12(9), 6089-6103; https://doi.org/10.3390/ijms12096089 - 19 Sep 2011

Cited by 34 | Viewed by 12139

Abstract

This study was carried out with fresh Australian lager beer which was sampled directly off the production line, the same samples aged for 12 weeks at 30 °C, and the vintage beer which was kept at 20 °C for 5 years. Characteristic Australian [...] Read more.

This study was carried out with fresh Australian lager beer which was sampled directly off the production line, the same samples aged for 12 weeks at 30 °C, and the vintage beer which was kept at 20 °C for 5 years. Characteristic Australian lager flavour was maintained in the fresh and vintage beers but was lost in the aged beer. Sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) and free thiol group labelling analyses of beer proteins found that this flavour stability correlated with the presence of an unknown 10 kilodaltons (kDa) protein with a higher level of free thiols. The protein was purified by size-exclusion chromatography, then peptide sequencing and database matching identified it as the barley lipid transfer protein (LTP1). Further characterisation using diphenylpicrylhydrazyl (DPPH) free radical scavenging and a Saccharomyces cerevisiae-based antioxidant screening assay demonstrated that the LTP1 protein was active in DPPH reduction and antioxidant activity. The absence of free thiol in the aged beer indicates that the thiol functional groups within the LTP1 protein were saturated and suggests that it is important in the flavour stability of beer by maintaining reduction capacity during the ageing process. Full article

(This article belongs to the Special Issue Antioxidants)

► Show Figures

691 KiB

Open AccessArticle

The Antioxidant Activity of New Coumarin Derivatives

by Abdul Amir H. Kadhum, Ahmed A. Al-Amiery, Ahmed Y. Musa and Abu Bakar Mohamad

Int. J. Mol. Sci. 2011, 12(9), 5747-5761; https://doi.org/10.3390/ijms12095747 - 7 Sep 2011

Cited by 160 | Viewed by 14766

Abstract

The antioxidant activity of two synthesized coumarins namely, N-(4,7-dioxo-2-phenyl-1,3-oxazepin-3(2H,4H,7H)-yl)-2-(2-oxo-2H-chromen-4-yloxy)acetamide 5 and N-(4-oxo-2-phenylthiazolidin-3-yl)-2-(2-oxo-2H-chromen-4-yloxy)acetamide 6 were studied with the DPPH, hydrogen peroxide and nitric oxide radical methods and compared with the known antioxidant [...] Read more.

The antioxidant activity of two synthesized coumarins namely, N-(4,7-dioxo-2-phenyl-1,3-oxazepin-3(2H,4H,7H)-yl)-2-(2-oxo-2H-chromen-4-yloxy)acetamide 5 and N-(4-oxo-2-phenylthiazolidin-3-yl)-2-(2-oxo-2H-chromen-4-yloxy)acetamide 6 were studied with the DPPH, hydrogen peroxide and nitric oxide radical methods and compared with the known antioxidant ascorbic acid. Compounds 5 and 6 were synthesized in a good yield from the addition reaction of maleic anhydride or mercaptoacetic acid to compound 4， namely N'-benzylidene-2-(2-oxo-2H-chromen-4-yloxy)acetohydrazide. Compound 4 was synthesized by the condensation of compound 3, namely 2-(2-oxo-2H-chromen-4-yloxy) acetohydrazide, with benzaldehyde. Compound 3, however, was synthesized from the addition of hydrazine to compound 2, namely ethyl 2-(2-oxo-2H-chromen-4-yloxy)acetate, which was synthesized from the reaction of ethyl bromoacetate with 4-hydroxycoumarin 1. Structures for the synthesized coumarins 2–6 are proposed on the basis of spectroscopic evidence. Full article

(This article belongs to the Special Issue Antioxidants)

► Show Figures

236 KiB

Open AccessArticle

Synthesis of Xylooligosaccharides of Daidzein and Their Anti-Oxidant and Anti-Allergic Activities

by Kei Shimoda, Hiroki Hamada and Hatsuyuki Hamada

Int. J. Mol. Sci. 2011, 12(9), 5616-5625; https://doi.org/10.3390/ijms12095616 - 31 Aug 2011

Cited by 31 | Viewed by 7959

Abstract

The biocatalytic synthesis of xylooligosaccharides of daidzein was investigated using cultured cells of Catharanthus roseus and Aspergillus sp. β-xylosidase. The cultured cells of C. roseus converted daidzein into its 4'-O-β-glucoside, 7-O-β-glucoside, and 7-O-β-primeveroside, which was a new [...] Read more.

The biocatalytic synthesis of xylooligosaccharides of daidzein was investigated using cultured cells of Catharanthus roseus and Aspergillus sp. β-xylosidase. The cultured cells of C. roseus converted daidzein into its 4'-O-β-glucoside, 7-O-β-glucoside, and 7-O-β-primeveroside, which was a new compound. The 7-O-β-primeveroside of daidzein was further xylosylated by Aspergillus sp. β-xylosidase to daidzein trisaccharide, i.e., 7-O-[6-O-(4-O-(β-D-xylopyranosyl))-β-D-xylopyranosyl]-β-D-glucopyranoside, which was a new compound. The 4'-O-β-glucoside, 7-O-β-glucoside, and 7-O-β-primeveroside of daidzein exerted DPPH free-radical scavenging and superoxide radical scavenging activity. On the other hand, 7-O-β-glucoside and 7-O-β-primeveroside of daidzein showed inhibitory effects on IgE antibody production. Full article

(This article belongs to the Special Issue Antioxidants)

► Show Figures

1025 KiB

Open AccessArticle

Chemical Structures of 4-Oxo-Flavonoids in Relation to Inhibition of Oxidized Low-Density Lipoprotein (LDL)-Induced Vascular Endothelial Dysfunction

by Long Yi, Xin Jin, Chun-Ye Chen, Yu-Jie Fu, Ting Zhang, Hui Chang, Yong Zhou, Jun-Dong Zhu, Qian-Yong Zhang and Man-Tian Mi

Int. J. Mol. Sci. 2011, 12(9), 5471-5489; https://doi.org/10.3390/ijms12095471 - 26 Aug 2011

Cited by 38 | Viewed by 10240

Abstract

Vascular endothelial dysfunction induced by oxidative stress has been demonstrated to be the initiation step of atherosclerosis (AS), and flavonoids may play an important role in AS prevention and therapy. Twenty-three flavonoids categorized into flavones, flavonols, isoflavones, and flavanones, all with 4-oxo-pyronenucleus, were [...] Read more.

Vascular endothelial dysfunction induced by oxidative stress has been demonstrated to be the initiation step of atherosclerosis (AS), and flavonoids may play an important role in AS prevention and therapy. Twenty-three flavonoids categorized into flavones, flavonols, isoflavones, and flavanones, all with 4-oxo-pyronenucleus, were examined for what structural characteristics are required for the inhibitory effects on endothelial dysfunction induced by oxidized low-density lipoprotein (oxLDL). Human vascular endothelial cells EA.hy926 were pretreated with different 4-oxo-flavonoids for 2 hs, and then exposed to oxLDL for another 24 hs. Cell viability and the level of malondialdehyde (MDA), nitric oxide (NO) and soluble intercellular adhesion molecule-1 (sICAM-1) were measured, respectively. Then, correlation analysis and paired comparison were used to analyze the structure–activity relationships. Significant correlations were observed between the number of –OH moieties in total or in B-ring and the inhibitory effectson endothelial dysfunction. Furthermore, 3',4'-ortho-dihydroxyl on B-ring, 3-hydroxyl on C-ring and 2,3-double bondwere correlated closely to the inhibitory effects of flavonolson cell viability decrease and lipid peroxidation. 5,7-meta-dihydroxyl group on A-ring was crucial for the anti-inflammatory effects of flavones and isoflavones in endothelial cells. Moreover, the substituted position of B-ring on C3 rather than C2 was important for NO release. Additionally, hydroxylation at C6 position significantly attenuated the inhibitory effects of 4-oxo-flavonoids on endothelial dysfunction. Our findings indicated that the effective agents in inhibiting endothelial dysfunction include myricetin, quercetin, luteolin, apigenin, genistein and daidzein. Our work might provide some evidence for AS prevention and a strategy for the design of novel AS preventive agents. Full article

(This article belongs to the Special Issue Antioxidants)

► Show Figures

331 KiB

Open AccessArticle

Polyphenolic Contents and Antioxidant Potential of Stem Bark Extracts from Jatropha curcas (Linn)

by Osamuyimen O. Igbinosa, Isoken H. Igbinosa, Vincent N. Chigor, Olohirere E. Uzunuigbe, Sunday O. Oyedemi, Emmanuel E. Odjadjare, Anthony I. Okoh and Etinosa O. Igbinosa

Int. J. Mol. Sci. 2011, 12(5), 2958-2971; https://doi.org/10.3390/ijms12052958 - 5 May 2011

Cited by 89 | Viewed by 12443

Abstract

We assessed the polyphenolic contents and antioxidant potential of the aqueous, ethanol and methanol stem bark extracts of Jatropha curcas. The total phenol, flavonoids, flavonols and proanthocyanidin contents of the extracts were evaluated to determine their effect on the antioxidant property of [...] Read more.

We assessed the polyphenolic contents and antioxidant potential of the aqueous, ethanol and methanol stem bark extracts of Jatropha curcas. The total phenol, flavonoids, flavonols and proanthocyanidin contents of the extracts were evaluated to determine their effect on the antioxidant property of this plant, using standard phytochemical methods. The antioxidant and free radical scavenging activity of ethanol, methanol and aqueous extracts of the plant were also assessed against 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2’-azino-bis-(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS), ferric reducing, nitric oxide (NO), superoxide anion, (O₂⁻) and hydrogen peroxide (H₂O₂) using spectroscopic methods and results were compared with that of butylated hydroxyl toluene (BHT) and ascorbic acid as standards. The concentrations of different classes of phenolic compounds were higher in methanol and ethanol extracts compared to aqueous extracts. There was correlation between total phenol, total flavonoids, total flavonol and total proanthocyanidins (r = 0.996, 0.978, 0.908, and 0.985) respectively. There was correlations between the amount of phenolic compounds and percentage inhibition of DPPH radicals scavenging activity of the extract (r = 0.98). Findings from the present study indicated that J. curcas is a potential source of natural antioxidants and may be a good candidate for pharmaceutical plant based products. Full article

(This article belongs to the Special Issue Antioxidants)

► Show Figures

Review

Jump to: Research

219 KiB

Open AccessReview

Inflammation, Oxidative Stress, and Obesity

by Alba Fernández-Sánchez, Eduardo Madrigal-Santillán, Mirandeli Bautista, Jaime Esquivel-Soto, Ángel Morales-González, Cesar Esquivel-Chirino, Irene Durante-Montiel, Graciela Sánchez-Rivera, Carmen Valadez-Vega and José A. Morales-González

Int. J. Mol. Sci. 2011, 12(5), 3117-3132; https://doi.org/10.3390/ijms12053117 - 13 May 2011

Cited by 1115 | Viewed by 43832

Abstract

Obesity is a chronic disease of multifactorial origin and can be defined as an increase in the accumulation of body fat. Adipose tissue is not only a triglyceride storage organ, but studies have shown the role of white adipose tissue as a producer [...] Read more.

Obesity is a chronic disease of multifactorial origin and can be defined as an increase in the accumulation of body fat. Adipose tissue is not only a triglyceride storage organ, but studies have shown the role of white adipose tissue as a producer of certain bioactive substances called adipokines. Among adipokines, we find some inflammatory functions, such as Interleukin-6 (IL-6); other adipokines entail the functions of regulating food intake, therefore exerting a direct effect on weight control. This is the case of leptin, which acts on the limbic system by stimulating dopamine uptake, creating a feeling of fullness. However, these adipokines induce the production of reactive oxygen species (ROS), generating a process known as oxidative stress (OS). Because adipose tissue is the organ that secretes adipokines and these in turn generate ROS, adipose tissue is considered an independent factor for the generation of systemic OS. There are several mechanisms by which obesity produces OS. The first of these is the mitochondrial and peroxisomal oxidation of fatty acids, which can produce ROS in oxidation reactions, while another mechanism is over-consumption of oxygen, which generates free radicals in the mitochondrial respiratory chain that is found coupled with oxidative phosphorylation in mitochondria. Lipid-rich diets are also capable of generating ROS because they can alter oxygen metabolism. Upon the increase of adipose tissue, the activity of antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx), was found to be significantly diminished. Finally, high ROS production and the decrease in antioxidant capacity leads to various abnormalities, among which we find endothelial dysfunction, which is characterized by a reduction in the bioavailability of vasodilators, particularly nitric oxide (NO), and an increase in endothelium-derived contractile factors, favoring atherosclerotic disease. Full article

(This article belongs to the Special Issue Antioxidants)

► Show Figures

222 KiB

Open AccessReview

Antioxidant Properties of Aminoethylcysteine Ketimine Decarboxylated Dimer: A Review

by Alberto Macone, Mario Fontana, Marco Barba, Bruno Botta, Mirella Nardini, Francesca Ghirga, Andrea Calcaterra, Laura Pecci and Rosa Marina Matarese

Int. J. Mol. Sci. 2011, 12(5), 3072-3084; https://doi.org/10.3390/ijms12053072 - 12 May 2011

Cited by 11 | Viewed by 9086

Abstract

Aminoethylcysteine ketimine decarboxylated dimer is a natural sulfur-containing compound detected in human plasma and urine, in mammalian brain and in many common edible vegetables. Over the past decade many studies have been undertaken to identify its metabolic role. Attention has been focused on [...] Read more.

Aminoethylcysteine ketimine decarboxylated dimer is a natural sulfur-containing compound detected in human plasma and urine, in mammalian brain and in many common edible vegetables. Over the past decade many studies have been undertaken to identify its metabolic role. Attention has been focused on its antioxidant properties and on its reactivity against oxygen and nitrogen reactive species. These properties have been studied in different model systems starting from plasma lipoproteins to specific cellular lines. All these studies report that aminoethylcysteine ketimine decarboxylated dimer is able to interact both with reactive oxygen and nitrogen species (hydrogen peroxide, superoxide anion, hydroxyl radical, peroxynitrite and its derivatives). Its antioxidant activity is similar to that of Vitamin E while higher than other hydrophilic antioxidants, such as trolox and N-acetylcysteine. Full article

(This article belongs to the Special Issue Antioxidants)

► Show Figures

Journal Menu

Journal Browser

Antioxidants

Share This Special Issue

Special Issue Editor

Special Issue Information

Keywords

Benefits of Publishing in a Special Issue

Related Special Issues

Published Papers (18 papers)

Research

Review

Further Information

Guidelines

MDPI Initiatives

Follow MDPI