Inhibitory effects of isoflavones on nitric oxide- or peroxynitrite-mediated DNA damage in RAW 264.7 cells and phiX174 DNA

Free radical scavenging and anti-isolated human LDL oxidation activities of Butea superba Roxb. extract

BACKGROUND

Butea superba Roxb. (B. superba), is an herbal plant traditionally used for rejuvenation. Additionally, there have been reports on its antioxidant properties. Low-density lipoproteins (LDL) oxidation is the leading cause of cardiovascular diseases (CVDs). Natural products with antioxidant properties have the potential to inhibit LDL oxidation. However, no work has been done about the anti-isolated human LDL oxidation of B. superba extract (BSE). This study aimed to investigate the antioxidant potential of BSE and its ability to prevent isolated human (LDL) oxidation induced by free radical agents.

METHODS

The antioxidant properties were investigated by antioxidant assays, including 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2-azinobis-(3-ethylbenzothiazoline)-6-sulfonic acid (ABTS), ferric reducing ability power (FRAP), nitric oxide (NO) and peroxynitrite scavenging assay. More so, anti-isolated human LDL oxidation activities were evaluated by 2,2'-azobis (2-amidinopropane) dihydrochloride (AAPH) and 3-morpholinosydnonimine hydrochloride (SIN-1) induced LDL oxidation assay.

RESULTS

BSE exhibited a significant (p < 0.05) antioxidant activity in all the test systems, demonstrating its potential as a potent free radical scavenger. It displayed scavenging effects on DPPH (p < 0.05; IC50 = 487.67 ± 21.94 µg/ml), ABTS (p < 0.05; IC50 = 30.83 ± 1.29 µg/ml). Furthermore, it generated significantly (p < 0.05) increased antioxidant capacity in a dose-dependent manner in FRAP assay and exhibited significantly (p < 0.01) higher percent NO scavenging activity than gallic acid. Besides, BSE at 62.5 µg/ml exhibited a considerable percent peroxynitrite scavenging of 71.40 ± 6.59% after a 2 h period. Moreover, BSE demonstrated anti-isolated human LDL oxidation activity induced by AAPH and SIN-1 (p < 0.05) and revealed scavenging activity similar to ascorbic acid (p > 0.05). Identifying the main constituents of BSE revealed the presence of genistein, daidzein, and biochanin A through Liquid Chromatography-Mass Spectrometer/Mass Spectrometer (LC-MS/MS) analysis.

CONCLUSION

This is the first report that the presence of isoflavones in BSE could play an important role in its antioxidation and isolated human LDL oxidation scavenging properties. These findings suggest the potential for developing antioxidant herbal supplements. However, further studies must be investigated, including efficacious and safe human dosages.

Deciphering the anticancer, anti-inflammatory and antioxidant potential of Ti nanoparticles fabricated using Zingiber officinale

Rapid and sustainable green technology was implemented in the current study to fabricated Ti nanoparticles. The vegetable ginger with the scientific name Zingiber officinale was employed as a biological source in the fabrication process of nanoparticles. The optical, structural, morphological, and particle size of the fabricated Ti nanoparticles were characterized with the help of UV-visible absorption spectrum, FTIR (Fourier Transform Infrared) spectrum, SEM (Scanning Electron Microscope) analysis, DLS (Dynamic Light Scattering) technique and XRD (X-ray powder diffraction) crystallography technique. The presence of spherical-shaped Ti nanoparticles with an average particle size of 93 nm was confirmed based on these characterization techniques. The anti-cancer properties of the Z. officinale mediated Ti nanoparticles were analyzed through MTT assay against cell lines MCF-7 (Human breast adenocarcinoma cell line) and concentration-dependent anti-cancer properties were observed. The anti-inflammatory capacity of the Z. officinale mediated Ti nanoparticles were examined through protein denaturation and nitric oxide scavenging assay. The antioxidant capacity of the Z. officinale mediated Ti nanoparticles were examined through DPPH assay, hydrogen peroxide radical scavenging assay, hydroxyl radical scavenging assay, and FRAP (Ferric Reducing Antioxidant Power) analysis. The fabricated Ti nanoparticles exhibited anti-inflammatory and antioxidant capacity in a concentration-dependent pattern.

Dietary Modulation of Bacteriophages as an Additional Player in Inflammation and Cancer

Natural compounds such as essential oils and tea have been used successfully in naturopathy and folk medicine for hundreds of years. Current research is unveiling the molecular role of their antibacterial, anti-inflammatory, and anticancer properties. Nevertheless, the effect of these compounds on bacteriophages is still poorly understood. The application of bacteriophages against bacteria has gained a particular interest in recent years due to, e.g., the constant rise of antimicrobial resistance to antibiotics, or an increasing awareness of different types of microbiota and their potential contribution to gastrointestinal diseases, including inflammatory and malignant conditions. Thus, a better knowledge of how dietary products can affect bacteriophages and, in turn, the whole gut microbiome can help maintain healthy homeostasis, reducing the risk of developing diseases such as diverse types of gastroenteritis, inflammatory bowel disease, or even cancer. The present review summarizes the effect of dietary compounds on the physiology of bacteriophages. In a majority of works, the substance class of polyphenols showed a particular activity against bacteriophages, and the primary mechanism of action involved structural damage of the capsid, inhibiting bacteriophage activity and infectivity. Some further dietary compounds such as caffeine, salt or oregano have been shown to induce or suppress prophages, whereas others, such as the natural sweeter stevia, promoted species-specific phage responses. A better understanding of how dietary compounds could selectively, and specifically, modulate the activity of individual phages opens the possibility to reorganize the microbial network as an additional strategy to support in the combat, or in prevention, of gastrointestinal diseases, including inflammation and cancer.

Genome-Protecting Compounds as Potential Geroprotectors

Throughout life, organisms are exposed to various exogenous and endogenous factors that cause DNA damages and somatic mutations provoking genomic instability. At a young age, compensatory mechanisms of genome protection are activated to prevent phenotypic and functional changes. However, the increasing stress and age-related deterioration in the functioning of these mechanisms result in damage accumulation, overcoming the functional threshold. This leads to aging and the development of age-related diseases. There are several ways to counteract these changes: 1) prevention of DNA damage through stimulation of antioxidant and detoxification systems, as well as transition metal chelation; 2) regulation of DNA methylation, chromatin structure, non-coding RNA activity and prevention of nuclear architecture alterations; 3) improving DNA damage response and repair; 4) selective removal of damaged non-functional and senescent cells. In the article, we have reviewed data about the effects of various trace elements, vitamins, polyphenols, terpenes, and other phytochemicals, as well as a number of synthetic pharmacological substances in these ways. Most of the compounds demonstrate the geroprotective potential and increase the lifespan in model organisms. However, their genome-protecting effects are non-selective and often are conditioned by hormesis. Consequently, the development of selective drugs targeting genome protection is an advanced direction.

The effects of isoflavone supplementation plus combined exercise on salivary markers of oxidative stress in postmenopausal women

This study tested the effect of isoflavone supplementation in addition to combined exercise training in salivary oxidative stress markers in non-obese postmenopausal women. Thirty-two postmenopausal women without hormone therapy were randomly assigned to exercise + placebo (n = 15) or exercise + isoflavone supplementation (n = 17) groups. They performed 30 sessions of combined exercises (aerobic plus resistance) over ten weeks and consumed 100 mg of isoflavone supplementation or placebo. Saliva samples were collected after an overnight fast. Superoxide dismutase, total antioxidant capacity, thiobarbituric acid reactive substances, catalase, total protein and nitrite were determined before and after ten weeks of the intervention. The ANOVA two-way analysis of variance was applied with α of 5%. Both groups increase (p<0.05) superoxide dismutase activity and decrease catalase levels. There was interaction (time × group) in both nitrite and thiobarbituric acid reactive substances results, with increase (p<0.05) in placebo group and decrease (p<0.05) in isoflavone group. No difference was found for total antioxidant capacity or total protein. The combination of isoflavone supplementation and exercise training can promote an antioxidant effect through reduction of lipid peroxidation and concentrations of salivary nitrite.

Phytoestrogens mediated anti-inflammatory effect through suppression of IRF-1 and pSTAT1 expressions in lipopolysaccharide-activated microglia

Microglial activation has been implicated in various neurological disorders, including Alzheimer's disease, Parkinson's disease, multiple sclerosis, and HIV encephalopathy. Phytoestrogens have been shown to be neuroprotective in neurotoxicity models; however, their effect on microglia has not been well established. In the current study, we report that the soy phytoestrogens, genistein, daidzein, and coumestrol, decreased nitric oxide (NO) production induced by lipopolysaccharide (LPS) in the rat microglial cell line (HAPI). The levels of inducible NO synthase (iNOS) mRNA and protein expression were also reduced. Transcription factors known to govern iNOS expression including interferon regulatory factor-1 (IRF-1) and phosphorylated STAT1 were down regulated. These observations explain, at least in part, the inhibitory effect of phytoestrogens on NO production. The levels of monocyte chemoattractant protein-1 and interleukin-6 mRNA, proinflammatory chemokine and cytokine associated with various neurological disorders, were also reduced following LPS stimulation when HAPI cells were pretreated with phytoestrogens. Hence, genistein, daidzein, and coumestrol could serve as anti-inflammatory agents and may have beneficial effects in the treatment of neurodegenerative diseases.

Comparative effect of genistein and daidzein on the expression of MCP-1, eNOS, and cell adhesion molecules in TNF-α-stimulated HUVECs

We compared the effects of genistein and daidzein on the expression of chemokines, cell adhesion molecules (CAMs), and endothelial nitric oxide synthase (eNOS) in tumor necrosis factor (TNF)-α-stimulated human umbilical vascular endothelial cells (HUVECs). TNF-α exposure significantly increased expression of monocyte chemoattractant protein (MCP)-1, vascular adhesion molecule (VCAM)-1, and intercellular adhesion molecule-1. Genistein significantly decreased MCP-1 and VCAM-1 production in a dose-dependent manner, whereas CAM expression was not significantly lowered by genistein treatment. However, daidzein slightly decreased MCP-1 production. The effects of genistein and daidzein on MCP-1 secretion coincided with mRNA expression. Pre-treatment with either genistein or daidzein elevated eNOS expression and nitric oxide production disturbed by TNF-α exposure. A low concentration of isoflavones significantly inhibited nuclear factor (NF)κB activation, whereas a high dose slightly ameliorated these inhibitive effects. These results suggest that genistein had a stronger effect on MCP-1 and eNOS expression than that of daidzein. Additionally, NFκB transactivation might be partially related to the down-regulation of these mRNAs in TNF-α-stimulated HUVECs.

Tomato ( Lycopersicon esculentum ) seeds: new flavonols and cytotoxic effect

In this study, seeds of Lycopersicon esculentum Mill. were analyzed by HPLC/UV-PAD/MS(n)-ESI. Fourteen flavonoids were identified, including quercetin, kaempferol, and isorhamnetin derivatives, with 13 of them being reported for the first time in tomato seeds. The major identified compounds were quercetin-3-O-sophoroside, kaempferol-3-O-sophoroside, and isorhamnetin-3-O-sophoroside. A significant cell proliferation inhibition (>80%), against rat basophile leukemia (RBL-2H3) cell line, was observed with this extract (IC(50) = 5980 microg/mL). For acetylcholinesterase inhibitory activity, a concentration-dependent effect was verified (IC(20) = 2400 microg/mL). The same behavior was noted regarding antioxidant capacity, evaluated against DPPH (IC(10) = 284 microg/mL), nitric oxide (IC(25) = 396 microg/L), and superoxide radicals (IC(25) = 3 microg/mL).

Suppressive effects of hydroxytyrosol on oxidative stress and nuclear Factor-kappaB activation in THP-1 cells

This study was designed to investigate whether hydroxytyrosol (HT) may ameliorate oxidative stress and nuclear factor kappaB (NF-kappaB) activation in the lipopolysaccharide (LPS)-stimulated THP-1 cell line. We measured the intracellular reactive oxygen species (ROS) formation using 2,7-dichlorofluorescein diacetate (DCFH-DA) as a fluorescent probe. Intracellular glutathione (GSH) level was estimated by fluorometric methods. Nitric oxide (NO) production was measured as nitrite (a stable metabolite of NO) concentrations using the Griess reagent system following Jiancheng Institute of Biotechnology protocols. To study the effect of HT on LPS-induced NF-kappaB activation in THP-1 cells, Western blot analysis of the nuclear fraction of cell lysates was performed. The results showed that treatment of THP-1 cells with HT significantly reduced LPS-stimulated NO production and ROS formation in a concentration-dependent manner. HT at 50 and 100 microM concentrations increased the GSH level. The specific DNA-binding activities of NF-kappaB on nuclear extracts from 50 and 100 microM HT treatments were significantly suppressed. The antioxidant N-acetylcysteine (NAC) also showed the same effects as HT on LPS-induced ROS and NO generation, change of GSH level, and NF-kappaB activation. These findings suggest that HT has antioxidant activity to suppress intracellular oxidative stress and NF-kappaB activation in THP-1 cells.

Isoflavone daidzein possesses no antioxidant activities in cell-free assays but induces the antioxidant enzyme catalase

Epidemiologic studies have shown that dietary intake of isoflavonones is associated with several properties beneficial to human health. It has been suggested that at least some of these effects are related to the antioxidant activity of isoflavonoids. We analyzed the antioxidant activity of the major isoflavones found in soybeans, but none of these compounds showed prominent antioxidant effects in cell-free assay systems (trolox equivalent antioxidant capacity assay and 2,2-diphenyl-1-picrylhydrazyl assay). Therefore, we examined the hypothesis that the antioxidative effects of isoflavones are caused indirectly by up-regulation of antioxidative enzymes, thereby lowering intracellular concentration of reactive oxygene species. Daidzein shows a significant induction of catalase promoter activity at 100 micromol/L in a reporter gene assay and at 200 micromol/L in Northern blot experiments. Another hypothesis for antioxidant effects caused by isoflavones is due to metabolism by intestinal bacteria. Analyzing the daidzein metabolites 3'-OH-daidzein and 6-OH-daidzein in our cell culture model, we found strong antioxidant effects (2,2-diphenyl-1-picrylhydrazyl and trolox equivalent antioxidant capacity assay). We conclude that isoflavone daidzein up-regulates the antioxidant enzyme catalase but shows only little antioxidant capacity per se. Antioxidant effects of this dietary isoflavonone may also be due to formation of the antioxidant metabolites 6-OH-daidzein and 3'-OH-daidzein.

Tronchuda cabbage (Brassica oleracea L. var. costata DC): scavenger of reactive nitrogen species

The ability of tronchuda cabbage ( Brassica oleracea L. var. costata DC) to act as a scavenger of the reactive nitrogen species nitric oxide and peroxynitrite was investigated. The aqueous extracts obtained from tronchuda cabbage seeds and from its external and internal leaves exhibited a concentration dependent scavenging capacity. The antioxidant potential observed against the two reactive species was as follows: seeds > external leaves > internal leaves. In order to establish a possible correlation with the chemical composition of the extracts, the activity of ascorbic and sinapic acids and kaempferol 3- O-rutinoside was also studied. Among the compounds tested, sinapic acid showed the strongest antioxidant activity against both species.

Protective effects of green tea polyphenols in the 6-OHDA rat model of Parkinson's disease through inhibition of ROS-NO pathway

BACKGROUND

Nitric oxide (NO) and related pathways are thought to play an important role in the pathogenesis of Parkinson's disease (PD). Our in vitro experiments suggested that green tea polyphenols (GTP) might protect dopamine neurons through inhibition of NO and reactive oxygen species (ROS).

METHODS

Immunohistochemistry, terminal deoxynucleotidyl transferase-mediated dUTP Nick End Labeling assay, electron spin resonance spin trapping, enzyme linked immunosorbent assay, and molecular biological methods were used to investigate the effects of GTP in an unilateral 6-hydroxydopamine (6-OHDA)-treated rat model of PD.

RESULTS

GTP treatment dose-dependently protected dopaminergic neurons by preventing from midbrain and striatal 6-OHDA-induced increase in 1) both ROS and NO levels, 2) lipid peroxidation, 3) nitrite/nitrate content, 4) inducible nitric oxide synthase, and 5) protein-bound 3-nitro-tyrosine. Moreover, GTP treatment dose-dependently preserved the free radical scavenging capability of both the midbrain and the striatum.

CONCLUSIONS

These results support the in vivo protection of GTP against 6-OHDA and suggest that GTP treatment might represent a neuroprotective treatment of PD.

Effects of soy germ isoflavones and hormone therapy on nitric oxide derivatives, low-density lipoprotein oxidation, and vascular reactivity in hypercholesterolemic postmenopausal women

OBJECTIVE

To evaluate the effects of soy germ isoflavones and hormone therapy on vascular reactivity, the formation of nitric oxide derivatives, and lipid peroxidation in hypercholesterolemic postmenopausal women.

DESIGN

Women were treated with soy germ, 17beta-estradiol or 17beta-estradiol + noretisterone acetate for 3 months after taking placebo for 1 month. The plasma concentrations of nitrite + nitrate and S-nitrosothiols were evaluated by gaseous phase chemiluminescence; nitrotyrosine, electronegative low-density lipoprotein, and estradiol levels were determined by enzyme-linked immunosorbent assay; cholesterol oxides and isoflavones were determined by gas chromatography and high-performance liquid chromatography, respectively. Vascular reactivity was analyzed by high-resolution ultrasonography.

RESULTS

Soy germ isoflavones and hormone therapy induced a decrease in nitrite + nitrate, electronegative low-density lipoprotein, and cholesterol oxides, as well as an increase in S-nitrosothiols. Soy germ isoflavones lowered electronegative low-density lipoprotein, and cholesterol oxides more efficiently than did hormone therapy. Only soy isoflavones inhibited nitrotyrosine formation. A significant improvement of vascular reactivity was only seen in women treated with 17beta-estradiol.

CONCLUSIONS

The soy germ isoflavones and 17beta-estradiol, alone or associated with noretisterone acetate, in the doses and forms used here, have similar effects on the bioavailability of nitric oxide. Soy germ treatment inhibited lipid peroxidation more effectively than hormone therapy.

Drugs modulating the biological effects of peroxynitrite and related nitrogen species

The term "reactive nitrogen species" includes nitrogen monoxide, commonly called nitric oxide, and some other remarkable chemical entities (peroxynitrite, nitrosoperoxycarbonate, etc.) formed mostly from nitrogen monoxide itself in biological environments. Regardless of the specific mechanisms implicated in their effects, however, it is clear that an integrated pharmacological approach to peroxynitrite and related species is only just beginning to take shape. The array of affected chemical and pathological processes is extremely broad. One of the most conspicuous mechanisms observed thus far has been the scavenging of the peroxynitrite anion by molecules endowed with antioxidant activity. This discovery has in turn lent great significance to several naturally occurring and synthetic antioxidants, which usually protect not only against oxidative reactions, but also from nitrating ones, both in vitro and in vivo. This has proven to be beneficial in different tissues, especially within the central nervous system. Taking these results and those of other biochemical investigations into account, many research lines are currently in progress to establish the true potential of reactive nitrogen species deactivators in the therapy of neurological diseases, ischemia-reperfusion damage, renal failure, and lung injury, among others.

Protective effect of green tea polyphenols on the SH-SY5Y cells against 6-OHDA induced apoptosis through ROS-NO pathway

Green tea polyphenols (GTP) are thought to help prevent oxidative stress-related diseases, such as cancer, cardiovascular disease, neurodegenerative disease, and aging. We here investigate the protective mechanisms of GTP on SH-SY5Y cells against apoptosis induced by the pro-parkinsonian neurotoxin 6-hydroxydopamine (6-OHDA). GTP rescued the changes in condensed nuclear and apoptotic bodies, attenuated 6-OHDA-induced early apoptosis, prevented the decrease in mitochondrial membrane potential, and suppressed accumulation of reactive oxygen species (ROS) and of intracellular free Ca(2+). GTP also counteracted the 6-OHDA-induced nitric oxide increase and overexpression of nNOS and iNOS, and decreased the level of protein-bound 3-nitrotyrosine (3-NT). In addition, GTP inhibited the autooxidation of 6-OHDA and scavenged oxygen free radicals in a dose- and time-dependent manner. Our results show that the protective effects of GTP on SH-SY5Y cells are mediated, at least in part, by controlling the ROS-NO pathway.

Antioxidative and Anti-Inflammatory Effects of Saururus chinensis Methanol Extract in RAW 264.7 Macrophages

Natural products are known to be sources of bioactive components exerting antioxidative and anti-inflammatory activities. We evaluated the suppressive effects of the methanol extract (0-45 microg/mL) of the aerial parts of Saururus chinensis (Lour.) Baill (Saururaceae) on lipopolysaccharide (LPS)-stimulated nitric oxide (NO) production and oxidative stress buildup in the RAW 264.7 murine macrophages. Treatment of RAW 264.7 cells with S. chinensis methanol extract (SME) significantly reduced LPS-stimulated NO production in a concentration-dependent manner. Treatment with SME reduced thiobarbituric acid-reactive substances accumulation and enhanced glutathione levels and activities of antioxidative enzymes, including superoxide dismutase, catalase, glutathione peroxidase, and glutathione reductase, in LPS-stimulated macrophages compared with LPS-only treated cells. Expression of inducible NO synthase (iNOS) mRNA was also suppressed in SMEtreated cells. The specific DNA binding activities of nuclear factor kappaB (NFkappaB) on nuclear extracts from SME-treated cells were significantly suppressed. These results suggest that SME has antioxidative and anti-inflammatory activities by enhancing antioxidative defense systems and suppressing NO production via the down-regulation of iNOS expression and NFkappaB activity.

Chlorella dichloromethane extract ameliorates NO production and iNOS expression through the down-regulation of NFκB activity mediated by suppressed oxidative stress in RAW 264.7 macrophages

BACKGROUND

It has been proposed that chlorella extracts have antioxidative and anti-inflammatory effects.

METHODS

RAW 264.7 murine macrophage cell line was preincubated with various concentrations (0-100 mug/ml) of chlorella dichloromethane extract (CDE) and stimulated with lipopolysaccharide (LPS) to induce oxidative stress and inflammation.

RESULTS

Treatments of CDE reduced thiobarbituric acid-reactive substances (TBARS) accumulation, enhancing glutathione level and activities of antioxidative enzymes including superoxide dismutase (SOD), catalase, glutathione peroxidase (GSH-px), and glutathione reductase in LPS-stimulated macrophages than LPS-only treated cells. Nitric oxide (NO) production was significantly suppressed in a dose-dependent manner (p<0.05) with an IC(50) of 30.5 microg/ml. Treatment of CDE at 50 microg/ml suppressed NO production to 6% of LPS-control. Treatment with CDE suppressed the levels of inducible nitric oxide synthase (iNOS) protein and mRNA expressions. The specific DNA binding activities of nuclear factor kappa B (NF kappa B) on nuclear extracts from CDE treatments were significantly suppressed with an IC(50) of 62.7 mug/ml in a dose-dependent manner.

CONCLUSIONS

CDE ameliorates NO production and iNOS expression through the down-regulation of NF kappa B activity, which may be mediated by attenuated oxidative stress in RAW 264.7 macrophages.

Dietary isoflavones suppress endotoxin-induced inflammatory reaction in liver and intestine

Dietary isoflavone intake has been linked to cancer prevention and their anti-inflammation activity was examined. Intraperitoneal lipopolysaccharide (LPS) injection in mice led to a decrease in the liver antioxidant glutathione level but this decrease was prevented in mice fed with an isoflavone-containing diet. Similarly, isoflavone diet prevented the inflammation-associated induction of metallothionein (MT) in the intestine; and the induction of manganese superoxide dismutase (Mn-SOD) in the liver. Results from the intestinal cell studies suggest that isoflavones suppress the intestinal response to inflammation by modulating the action of pro-inflammatory cytokine, IL-6. IL-6 secretion and the STAT3 (signal transducer and activator of transcription protein 3) nuclear translocation in response to IL-6 were both decreased by genistein.