Ambident reactivity of phenoxyl radicals in DNA adduction

2005 ◽  
Vol 83 (9) ◽  
pp. 1261-1267 ◽  
Author(s):  
Richard A Manderville
Keyword(s):  
Antioxidant Properties ◽  
Radical Scavenging ◽  
Phenoxyl Radicals ◽  
Beneficial Effects ◽  
Redox Active ◽  
Direct Reactions ◽  
Dna Adduction ◽  
Active Transition ◽  
Carcinogenic Process

Phenols are a class of compounds that can create beneficial effects in vivo owing to their antioxidant properties (through radical scavenging), or they can display hazardous effects owing to their pro-oxidant properties. The mechanism by which phenols act as pro-oxidants stems from their one-electron oxidation into reactive phenoxyl radicals by peroxidase enzymes or redox-active transition metals. In the presence of thiols and molecular oxygen, these reactive phenoxyl radicals stimulate an oxidative stress and cause oxidative damage to biomolecules, which is proposed to contribute to the occurrence of cancer in peroxidase rich tissues. Recent results from our laboratory show that certain phenoxyl radicals can also react directly with the C-8 site of deoxyguanosine to afford oxygen and carbon bonded adducts. This reactivity is consistent with the ambident (oxygen vs. C attachment) electrophilicity of phenoxyl radicals coupled with the susceptibility of the C-8 site of deoxyguanosine to radical attachment. Given that formation of covalent DNA adducts is regarded as the initiation event in the carcinogenic process, C-8 deoxyguanosine adducts of phenolic toxins are expected to contribute greatly to peroxidase driven toxic effects of phenolic xenobiotics. The focus of this review is the role of phenoxyl radicals in direct reactions with DNA and the use of Brown σ+ values to predict their reactivity.Key words: DNA adduction, phenoxyl radicals, chlorophenols, ochratoxin A, deoxyguanosine.

Punica granatum as a Source of Natural Antioxidant and Antimicrobial Agent; a Comprehensive Review on Related Investigations

2020 ◽  
Vol 17 ◽  
Author(s):  
Atefeh Jalali ◽  
Mohammadreza Kiafar ◽  
Masih Seddigh ◽  
Mohammad M. Zarshenas
Keyword(s):  
Antioxidant Activities ◽  
Antioxidant Properties ◽  
Radical Scavenging ◽  
Natural Antioxidants ◽  
Punica Granatum ◽  
Antimicrobial Activities ◽  
Natural Antioxidant ◽  
Antiviral Activities ◽  
Natural Foods

Background: The consumption of natural antioxidants is increasing due to the demand and tendency to natural foods. Punica granatum L. [Punicaceae] is a fruit with various bioactive ingredients. The effectiveness of this plant has been proved against various disorders such as hyperglycemia, hyperlipidemia, blood coagulation, infections, cancer, and dentistry. Among them, there are numerous researches on antimicrobial and antioxidant properties. Subsequently, the present study aimed to compile a review of those properties to outline this herb as a possible natural antioxidant and preservative. Methods: Synchronically, keywords "Punica granatum" with antimicrobial, or antibacterial, antifungal, antiviral, antioxidant and radical scavenging were searched through "Scopus" database up to 31st September 2019. Papers focusing on agriculture, genetics, chemistry, and environmental sciences were excluded and also related papers were collected. Results: Among 201 papers focusing on related activities, 111 papers have dealt with antioxidant activities focusing based on DPPH assay, 59 with antibacterial, on both gram+ and gram- bacteria, 24 with antifungal effects, mostly on Aspergillus niger and Candida albicans, and 7 papers with antiviral activities. There were about 50 papers focusing on in-vivo antioxidant activities of this plant. Conclusion: Taken together, botanical parts of P. granatum have possessed notable radical scavenging and antimicrobial activities that with these properties, this plant can be introduced as a natural safe source of preservative and antioxidant. Accordingly, P. granatum can be applied as excipient with the aforementioned properties in the pharmaceutical and food industries.

scholarly journals Hepatoprotective studies on methanolic extract fractions of Lindernia ciliata and development of qualitative analytical profile for the bioactive extract

2019 ◽  
Vol 5 (1) ◽  
Author(s):  
Praneetha Pallerla ◽  
Narsimha Reddy Yellu ◽  
Ravi Kumar Bobbala
Keyword(s):  
Methanolic Extract ◽  
Antioxidant Properties ◽  
Radical Scavenging ◽  
Liver Homogenate ◽  
Reducing Power ◽  
Hepatoprotective Activity ◽  
Total Phenolic ◽  
Effective Fraction

Abstract Background The objective of the study is to evaluate the hepatoprotective activity of methanolic extract fractions of Lindernia ciliata (LC) and development of qualitative analytical profile of the bioactive fraction using HPLC fingerprinting analysis. All the fractions of methanolic extract of Lindernia ciliata (LCME) are assessed for their total phenolic, flavonoid contents and in vitro antioxidant properties by using DPPH, superoxide, nitric oxide, hydroxyl radical scavenging activities and reducing power assay. Acute toxicity study was conducted for all the fractions and the two test doses 50 and 100 mg/kg were selected for the hepatoprotective study. Liver damage was induced in different groups of rats by administering 3 g/kg.b.w.p.o. paracetamol and the effect of fractions were tested for hepatoprotective potential by evaluating serum biochemical parameters and histology of liver of rats. The effective fraction was evaluated for its antihepatotoxic activity against D-Galactosamine (400 mg/kg b.w. i.p.) and in vivo antioxidant parameters viz., Glutathione (GSH), Melondialdehyde (MDA) and Catalase (CAT) levels are estimated using liver homogenate. Results Among all the fractions, butanone fraction of LCME, (BNF-LCME) has shown better hepatoprotective activity and hence it is selected to evaluate the antihepatotoxicity against D-GaIN. The activity of BNF-LCME is well supported in in vitro and in vivo antioxidant studies and may be attributed to flavonoidal, phenolic compounds present in the fraction. Hence, BNF-LCME was subjected to the development of qualitative analytical profile using HPLC finger printing analysis. Conclusions All the fractions of LCME exhibited significant hepatoprotective activity and BNF-LCME (50 mg/kg) was identified as the most effective fraction.

scholarly journals Antioxidant Properties of Ergosterol and Its Role in Yeast Resistance to Oxidation

Antioxidants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1024
Author(s):  
Sebastien Dupont ◽  
Paul Fleurat-Lessard ◽  
Richtier Gonçalves Cruz ◽  
Céline Lafarge ◽  
Cédric Grangeteau ◽  
...  
Keyword(s):  
Computational Study ◽  
Antioxidant Properties ◽  
Beneficial Effects ◽  
Tert Butyl Hydroperoxide ◽  
Resistance To Oxidation ◽  
Specific Accumulation ◽  
The Subject

Although the functions and structural roles of sterols have been the subject of numerous studies, the reasons for the diversity of sterols in the different eukaryotic kingdoms remain unclear. It is thought that the specificity of sterols is linked to unidentified supplementary functions that could enable organisms to be better adapted to their environment. Ergosterol is accumulated by late branching fungi that encounter oxidative perturbations in their interfacial habitats. Here, we investigated the antioxidant properties of ergosterol using in vivo, in vitro, and in silico approaches. The results showed that ergosterol is involved in yeast resistance to tert-butyl hydroperoxide and protects lipids against oxidation in liposomes. A computational study based on quantum chemistry revealed that this protection could be related to its antioxidant properties operating through an electron transfer followed by a proton transfer mechanism. This study demonstrates the antioxidant role of ergosterol and proposes knowledge elements to explain the specific accumulation of this sterol in late branching fungi. Ergosterol, as a natural antioxidant molecule, could also play a role in the incompletely understood beneficial effects of some mushrooms on health.

scholarly journals ANTIOXIDANT PROPERTIES OF SINAPIC ACID: IN VITRO AND IN VIVO APPROACH

2017 ◽  
Vol 10 (6) ◽  
pp. 255 ◽  
Author(s):  
Nithya R ◽  
Subramanian S
Keyword(s):  
Antioxidant Properties ◽  
Intraperitoneal Administration ◽  
Radical Scavenging ◽  
Sinapic Acid ◽  
Lipid Peroxides ◽  
Diabetic Rats ◽  
Antioxidant Potential ◽  
Protein Carbonyls

Objective: This study was aimed to evaluate the antioxidant potential of sinapic acid in both in vitro and in vivo. Recently, we have reported that oral administration of sinapic acid (3,5-dimethoxy 4-hydroxycinnamic acid) an active phyto ingredient widely distributed in rye, mustard, berries, and vegetables has been shown to ameliorate hyperglycemia.Methods: Experimental Type 2 diabetes was induced in male Wistar rats by feeding high-fat diet to induce insulin resistance followed by intraperitoneal administration of a single low dose streptozotocin (35 mg/kg body weight [bw]). Sinapic acid was administered orally at a concentration of 25 mg/kg bw/rat/day for 30 days, and its efficacy was compared with metformin. In vitro, antioxidant scavenging properties of sinapic acid were determined using 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS), superoxide, and nitric oxide (NO) assay.Results: Sinapic acid treatment showed a significant decline in the levels of lipid peroxides, hydroperoxides and protein carbonyls in the plasma and vital tissues of diabetic rats. The treatment also improved the antioxidant status in diabetic rats indicating the antioxidant potential of sinapic acid. In addition, the results of DPPH, ABTS, superoxide, and NO radical scavenging assays substantiate the free radical scavenging efficacy of sinapic acid.Conclusion: The results of this study evidenced that sinapic acid possess significant antioxidant properties which in turn may be responsible for its antidiabetic properties.

scholarly journals Evaluation of Antioxidant Properties ofPhaulopsis fascisepalaC.B.Cl. (Acanthaceae)

2009 ◽  
Vol 6 (2) ◽  
pp. 227-231 ◽  
Author(s):  
S. A. Adesegun ◽  
A. Fajana ◽  
C. I. Orabueze ◽  
H. A. B. Coker
Keyword(s):  
Ascorbic Acid ◽  
Leaf Extract ◽  
Antioxidant Activities ◽  
Antioxidant Properties ◽  
Radical Scavenging ◽  
Reducing Power ◽  
Total Phenolic ◽  
Chelating Ability

The antioxidant activities of crude extract ofPhaulopsis fascisepalaleaf were evaluated and compared with α-tocopherol and BHT as synthetic antioxidants and ascorbic acid as natural-based antioxidant.In vitro, we studied its antioxidative activities, radical-scavenging effects, Fe2+-chelating ability and reducing power. The total phenolic content was determined and expressed in gallic acid equivalent. The extract showed variable activities in all of thesein vitrotests. The antioxidant effect ofP. fascisepalawas strongly dose dependent, increased with increasing leaf extract dose and then leveled off with further increase in extract dose. Compared to other antioxidants used in the study, α-Tocopherol, ascorbic acid and BHT,P. fascisepalaleaf extract showed less scavenging effect on α,α,-diphenyl-β-picrylhydrazyl (DPPH) radical and less reducing power on Fe3+/ferricyanide complex but better Fe2+-chelating ability. These results revealed thein vitroantioxidant activity ofP.fascisepala.Further investigations are necessary to verify these activitiesin vivo.

scholarly journals Purification and Characterization of Bioactive Compounds Extracted from Suaeda Maritima Leaf and its Impact on Pathogenicity of Pseudomonas Aeruginosa in Catla Catla Fingerlings

2021 ◽  
Author(s):  
Beulah G ◽  
Divya D ◽  
Sampath Kumar N.S. ◽  
Sravya M.V.N. ◽  
Govinda Rao K ◽  
...  
Keyword(s):  
Antioxidant Activities ◽  
Antioxidant Properties ◽  
Radical Scavenging ◽  
Ethanolic Extract ◽  
In Vivo Studies ◽  
Catla Catla ◽  
Active Fraction ◽  
Efficient Treatment ◽  
Suaeda Maritima

Abstract Incidence of various dreadful microbial infections and the development of antibiotic resistance by infection causative microbes are the main reasons for reducing aquaculture productivity. Hence, there is an immense need for the discovery of alternative and efficient treatment for quick recovery of diseased fishes. In the present study, Suaeda maritima leaf extracts (hexane, diethyl ether, ethanol, and water) were screened for in vitro and in vivo antibacterial and antioxidant activities. Out of all the four extracts, ethanolic extract showed highest antibacterial activity against S.aureus (4.9±1.3 mm), B.subtilis (1.6±0.3 mm), K.pneumonia (4.2±1.8 mm), and P.aeruginosa (4.1±1.2 mm). Similarly, antioxidant activity was also higher for ethanolic extract (500 µg/ml) based on DPPH radical scavenging ability (71.6±1.4 %) and reducing potential (149 μg/mL) assays. Further, ethanolic extract was purified consecutively via column chromatography and preparative TLC where an active fraction was selected based on highest antibacterial (10.1±1.4 mm) and antioxidant properties (82.3±2.8 %). Active fraction was loaded onto mass spectroscopy and identified the presence of four active constituents such as 1,2,9,10-tetramethoxy-6-methyl-5,6,6a,7-tetrahydro-4H-dibenzo[de,g]quinolin-3-yl) methanol; 3',7-Dimethoxy-3-hydroxyflavone; Saponin and (19R)9acetyl19hydroxy10,14dimethyl20oxopentacyclo[11.8.0.0<2,10>.0<4,9>.0<14,19>]henicos-17-yl-acetate. Besides, in vivo studies were conducted on Catla catla fingerlings infected with P. aeruginosa under laboratory conditions. The fingerlings were segregated into 5 groups, among which group 4 and 5 were treated with crude and purified extracts. Both the extracts were efficient in treating infected fingerlings and recorded 100% survival rate which is even better than group-3 treated with a synthetic antibiotic (77%). Hence, S. maritima leaf extract can be considered as a possible alternative medicine in aquaculture

scholarly journals Polyphenols in human nutrition: from the in vitro antioxidant capacity to the beneficial effects on cardiometabolic health and related inter-individual variability – an overview and perspective

2019 ◽  
Vol 123 (3) ◽  
pp. 241-254 ◽  
Author(s):  
T. Ruskovska ◽  
V. Maksimova ◽  
D. Milenkovic
Keyword(s):  
Antioxidant Activity ◽  
Free Radical ◽  
Radical Scavenging ◽  
Individual Variability ◽  
Free Radical Scavengers ◽  
Cardiometabolic Health ◽  
Dietary Recommendations ◽  
Beneficial Effects

AbstractOxidative damage of cells and tissues is broadly implicated in human pathophysiology, including cardiometabolic diseases. Polyphenols, as important constituents of the human diet and potent in vitro free radical scavengers, have been extensively studied for their beneficial effects on cardiometabolic health. However, it has been demonstrated that the in vivo antioxidant activity of polyphenols is distinct from their in vitro free radical-scavenging capacity. Indeed, bioavailability of nutritional polyphenols is low and conditioned by complex mechanisms of absorption, distribution, metabolism and excretion. Nowadays, it is commonly accepted that the cellular antioxidant activity of polyphenols is mainly carried out via modification of transcription of genes involved in antioxidant defence. Importantly, polyphenols also contribute to cardiometabolic health by modulation of a plethora of cellular processes that are not directly associated with antioxidant enzymes, through nutri(epi)genomic mechanisms. Numerous human intervention studies have demonstrated beneficial effects of polyphenols on the key cardiometabolic risk factors. However, inconsistency of the results of some studies led to identification of the inter-individual variability in response to consumption of polyphenols. In perspective, a detailed investigation of the determinants of this inter-individual variability will potentially lead us towards personalised dietary recommendations. The phenomenon of inter-individual variability is also of relevance for supplementation with antioxidant (pro)vitamins.

scholarly journals Baru Pulp (Dipteryx alata Vogel): Fruit from the Brazilian Savanna Protects against Oxidative Stress and Increases the Life Expectancy of Caenorhabditis elegans via SOD-3 and DAF-16

Biomolecules ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1106
Author(s):  
Natasha Rios Leite ◽  
Laura Costa Alves de Araújo ◽  
Paola dos Santos da Rocha ◽  
Danielle Araujo Agarrayua ◽  
Daiana Silva Ávila ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Caenorhabditis Elegans ◽  
Life Expectancy ◽  
Biological Activities ◽  
Radical Scavenging ◽  
Brazilian Savanna ◽  
Beneficial Effects ◽  
Dipteryx Alata

Fruits are sources of bioactive compounds that are responsible for several biological activities. Therefore, this study aimed to identify the chemical composition of the pulp of the Brazilian Savanna fruit Dipteryx alata; evaluate its toxic effects, influence on the life expectancy of the nematode Caenorhabditis elegans, and its antioxidant activities in vitro and in vivo; and describe the mechanisms involved. The chemical compounds identified include phenols, terpenes, fatty acid derivatives, vitamins, and a carboxylic acid. The in vitro antioxidant activity was demonstrated by radical scavenging methods. in vivo, the D. alata fruit pulp was not toxic and promoted resistance to oxidative stress in nematodes exposed to a chemical oxidizing agent. Furthermore, it promoted an increased life expectancy in wild-type nematodes and increased the expression of superoxide dismutase and the nuclear translocation of DAF-16. These results suggest that the beneficial effects identified are related to these two genes, which are involved in the regulation of metabolic activities, the control of oxidative stress, and the lifespan of C. elegans. These beneficial effects, which may be related to its chemical constituents, demonstrate its potential use as a functional and/or nutraceutical food.

Allopurinol does not enhance antioxidant properties of extracellular fluid

1988 ◽  
Vol 255 (1) ◽  
pp. H202-H206 ◽  
Author(s):  
B. J. Zimmerman ◽  
D. A. Parks ◽  
M. B. Grisham ◽  
D. N. Granger
Keyword(s):  
Free Radical ◽  
Xanthine Oxidase ◽  
Hypochlorous Acid ◽  
Ischemia Reperfusion ◽  
Parenchymal Cell ◽  
Antioxidant Properties ◽  
Radical Scavenging ◽  
Extracellular Fluid ◽  
Free Radical Scavenging ◽  
Beneficial Effects

Allopurinol has been shown to provide significant protection against ischemia/reperfusion-induced microvascular and parenchymal cell injury. It has been hypothesized that the protection seen with allopurinol after ischemia/reperfusion (I/R) is caused by inhibition of xanthine oxidase. However, recent reports suggest that the beneficial effects of allopurinol in I/R may be caused by direct free radical scavenging. The objective of this study was to determine whether the regimen of allopurinol administration used in most I/R studies leads to a significant modification of the free radical scavenging properties of extracellular fluid (ECF), i.e., plasma and lymph. Plasma and intestinal lymph samples obtained from both control and allopurinol-treated cats were used to assess the following: 1) allopurinol and oxypurinol concentrations, 2) xanthine oxidase inhibition, 3) myoglobin-catalyzed linolenic acid peroxidation, 4) hypochlorous acid scavenging, and 5) protein and nonprotein sulfhydryl content. ECF from allopurinol-treated animals contained approximately 10 microM each of allopurinol and oxypurinol. Ten percent ECF resulted in 80% inhibition of xanthine oxidase activity. Comparable volumes of control ECF did not inhibit xanthine oxidase. Furthermore, allopurinol treatment did not enhance the antioxidant properties of ECF. The results of this study do not support the contention that the beneficial effects of allopurinol in I/R injury are caused by the scavenging of oxidants produced in ECF by activated granulocytes.

scholarly journals Investigation of invitro Antioxidant and invivo Protective Effects of Hypericum triquetrifolium Seed Methanol Extracts against Cyclophosphamide-Induced Acute Myelotoxicity, Hemotoxicity and Hepatotoxicity in Rats

2018 ◽  
Author(s):  
Songul Cetik Yildiz ◽  
Cumali Keskin ◽  
Adnan Ayhanci
Keyword(s):  
Antioxidant Activities ◽  
Antioxidant Properties ◽  
Radical Scavenging ◽  
Stress Index ◽  
Total Phenolic ◽  
Rat Tissues ◽  
Protective Effects ◽  
Methanol Extracts

The aim of this study was to investigate in-vitro antioxidant properties and in-vivo protective effects of different concentrations of Hypericum triquetrifolium Turra. (HT) seed methanol extracts against acute hepatotoxicity, myelotoxicity and hematotoxicity in rats exposed to overdose of cyclophosphamide (CP). HT seed methanol extracts were tested in view of its in-vitro antioxidant activities as total phenolic contents and DPPH free radical-scavenging activity. To investigate in-vivo protective effects of HT seed methanol extracts on rat tissues; tested animals were divided into nine groups. Three groups only were treated with HT extracts (25, 50 and 100 mg/kg HT) for 6 days. Three groups were pre-treated with the extract of HT (25, 50 and 100 mg/kg HT) for 6 days and on the last day they were injected with single dose of CP (150-mg/kg body weight). Two groups were used as control groups and one group was only treated with CP (150 mg/kg) on the 6th day. The toxic effects of CP and protective effects of HT extracts on the nucleated cells which were produced by bone marrow and serum alanine transaminase (ALT), alkaline phosphatase (ALP), lactate dehydrogenase (LDH), oxidative stress index (OSI) levels were investigated biochemically. Additionally, liver tissue samples were examined histopathologically. Our results show that HT seed methanol extract has high total phenolic content and antioxidant activity. Over dose CP administration caused hepatotoxicity, myelotoxicity and hematotoxicity on rat. Whereas, 25, 50 and 100 mg/kg HT plus CP administered groups showed significant protective effects on nucleated cells. And 25, 50, 100 mg/kg HT plus CP treated groups showed an important decrease on serum ALT, ALP, LDH and OSI levels when compared with CP treated group. Our results showed that the administration of different HT doses with high doses of CP significantly reduced hepatotoxicity, myelotoxicity and hematoxicity on rats.

Sign in / Sign up

Export Citation Format

Share Document