Natural Antioxidant Activity Research Articles

발아일수에 따른 해바라기 싹의 이화학적 특성 및 항산화성 비교

It is well known that sunflower (SF) sprout has more beneficial effects than SF seed due to increased levels of phytochemical components such as vitamins, total phenolics, and isoflavones during germination. This study investigated the physicochemical properties and antioxidative activities of SF seed during both germination and cultivation. In a proximate analysis, the water content of SF groat was 9.17% and then increased to 15.32% on the 11th day after seeding. On a dry weight basis, crude fat content decreased while the contents of carbohydrates, crude protein, and crude ash increased. As cultivation proceeded, the contents of minerals were in decreasing order of K, Mg, Ca, Na, Zn, Fe, Mn, and Cu, in which SF sprout cultivated for 9 or 11 days contained the highest mineral contents. Though vitamin C was not detected on SF groat, the content of vitamin C continuously increased up to the 5th day of cultivation and then decreased gradually. Vitamin E content in SF groat was higher than that in SF sprout. It was also found that the vitamin E content in SF sprout was the highest on the 5th day of cultivation. Daidzin was not detected in SF groat, but its concentration reached a maximum on the 5th day of cultivation in SF sprouts. Furthermore, higher amounts of daidzein were observed on the 3rd, 5th, and 9th days of cultivation. The highest total isoflavone content was observed on either the 3rd or 5th day of cultivation. The highest content of total phenolics was observed on the 5th of cultivation. When DPPH radical and peroxyl radical scavenging activities of SF sprout were measured in order to measure antioxidant efficacy, it was found that 5 day-cultivated SF sprout had the highest scavenging activities. In conclusion, SF sprout cultivated for 9 or 11 days was found to be a good source of minerals. Furthermore, the fifth-day after seeding was the optimal time for the production of SF sprout with effective natural antioxidant activity and high amounts of functional components such as vitamins, total phenolics, and isoflavones.

Alkali extraction and in vitro antioxidant activity of Monascus mycelium polysaccharides.

In the present work, alkali extraction technology was used to optimize the extraction of Monascus mycelium polysaccharides for the first time. The extracting parameters of alkali extracted Monascus mycelium polysaccharides were optimized by Box-Behnken design (BBD). The optimum conditions were extraction temperature 49°C, alkali concentration 7%, solvent/material ratio 23:1 (ml/g) and extraction time 2.3h with an enhanced yield of 10.1%, compared with the yield 4.76% of hot water extraction, indicating that alkali extraction is a more efficient way. In order to discuss the biological activity of alkali extracted polysaccharides, we compared the in vitro antioxidant activity of alkali extracted polysaccharides (AMP) with hot water extracted polysaccharides (HMP). The result showed that AMP have the similar capability of scavenging both superoxide radical and 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical of HMP in vitro. Therefore, alkali extraction technology is not only a high-efficiency way to extract AMP, but also can retain the natural antioxidant activities of AMP, which can be used in pharmaceutical and food industries.

In-vitro free radical scavenging activities of anthocyanins from three berries

The purpose of this study was to evaluate the antioxidant and free radical scavenging properties of anthocyanin extracts from three berries (Lonicera caerulea var. edulis,Vaccinium uliginosum Linn. and Rubus idaeus). The anthocyanins extracted were found to show remarkable scavenging activity on 2,2-Diphenyl-1-picrylhydrazyl (DPPH) radical, 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical, hydroxyl radical (•OH) and superoxide anion radical (•O2-). The effect of these three anthocyanins on their reducing power increases in a dose dependent manner. The results obtained in the present study indicate that the three anthocyanins can be a potential source for natural antioxidant activity. Key words: Anthocyanin, berry, free radical, antioxidant activity.

Modulation of the antioxidant activity of phenols by non-covalent interactions

Non-covalent (H-bonding) interactions, either intramolecular or with the surrounding medium, have a major influence on the activity of natural and synthetic phenolic antioxidants, due to the modulation of their reactivity with radical species, such as peroxyl radicals. Different cases can be distinguished. (i) Intra- or inter-molecular H-bonding involving the reactive -OH moiety will depress the antioxidant activity if the -OH acts as H-bond donor, while the opposite will generally occur if it acts as H-bond acceptor. (ii) Remote intra- and inter-molecular H-bonding, involving a distant -OH group (in polyphenols) or a ring substituent, may increase or decrease the reactivity of an antioxidant toward free radicals, depending on whether the stabilization produced by the H-bond increases or decreases along the reaction coordinate, on proceeding from reactants to the transition state. In this Perspective, the role of non-covalent interactions in the complex chemistry of natural polyphenolic antioxidants is discussed with the aid of literature data on simplified model compounds, aiming at the composition of a clear picture that might guide future research.

Anti-oxidant activities of extracts of the inflorescences and aerial parts of the herb, Artemisia amygdalina Decne.

SummaryThe aim of this study was to evaluate the anti-oxidant activities of petroleum ether, methanol, ethyl acetate, and aqueous extracts of the aerial parts and inflorescences of the herb, Artemisia amygdalina Decne. Methanolic extracts of the aerial parts and aqueous extracts of the inflorescences gave the maximum levels of inhibition (90.6% and 76.4%, respectively) in the 1, 1-diphenyl-2-picrylhydrazyl (DPPH) assay when compared to ascorbic acid, which showed 77.9% inhibition. The superoxide radical scavenging activity was highest in methanolic extracts of the aerial parts and in methanolic extracts of inflorescences (94.3% and 88.5%, respectively). These values were comparable to the reference standard, ascorbic acid, which showed 92.8% superoxide radical scavenging activity. In the deoxyribose assay, α-tocopherol showed 50.1% inhibition, while methanolic extracts of the aerial parts and inflorescences showed 46.2% and 46.4% inhibitory activity, respectively, against hydroxyl radicals. In the ferric thiocyanate assay, petroleum ether extracts of the aerial parts showed 78.7% inhibition, while ethyl acetate extracts of inflorescences showed 80.2% inhibition. The commercial standard, α-tocopherol, showed 79.7% scavenging activity. Extracts of A. amygdalina may provide an alternative source of natural anti-oxidant activity.

Effect of Ginkgo Biloba Extract 50 on Immunity and Antioxidant Enzyme Activities in Ischemia Reperfusion Rats

The aim of the study was to investigate the effect of Ginkgo biloba extract 50 (GBE50), a well-known natural antioxidant, against immunity and antioxidant enzyme activities in ischemia reperfusion (IR) rats. Rats were then divided into six groups fed for 15 days with the same diet: three groups (IV, V, VI) were treated by different doses of GBE50 suspension [20, 40, or 60 mg/kg body weight by oral gavage every day at a fixed time (10.00 a.m.)] (equal to 5, 10 and 20 times, respectively, the maximum recommended human dose), and three groups (I, II, III) were untreated. At the end of the experiment, rats’ hearts were subjected to 30 min of ischemia followed by 90 min of reperfusion. Results showed that IR significantly enhanced heart rate, S-T height, myocardium (myeloperoxidase) MPO activity and blood interleukin-8 (IL-8), tumor necrosis factor Alpha (TNF-α), interleukin-1β (IL-1β) levels, blood aspartate transaminase (AST), lactate dehydrogenase (LDH), and creatinine kinase (CK) activities, reduced myocardium sodium-potassium adenosine triphosphatase (Na+-K+-ATPase), calcium-magnesium adenosine triphosphatase (Ca2+-Mg2+-ATPase) activities and antioxidant enzyme activities in IR group (III) compared to sham control group (II). Pretreatment of GBE50 markedly significantly reduced heart rate, S-T height, myocardium MPO activity and blood IL-8, TNF-α, IL-1β levels, blood AST, LDH, and CK activities, enhanced myocardium Na+-K+-ATPase, Ca2+-Mg2+-ATPase activities and antioxidant enzyme activities in IR group (II) compared to IR group (III). The results suggested that the GBE50 may reduce the oxidative stress in the reperfused myocardium, and increased immunity and antioxidant activities in IR rats.

Isolation, identification and activity of natural antioxidants from horehound (Marrubium vulgare L.) cultivated in Lithuania

In an earlier screening of Lithuanian plants, horehound (Marrubium vulgare) showed good antioxidant activity and as this species is used in herbal teas and cough pastilles it was selected for further investigation. Some fractions of the aerial parts were strong scavengers of the model free radicals DPPH and ABTS+. Activity in the β-carotene bleaching assay and the rapeseed oil oxidation assay was lower. Several active compounds were observed in the crude methanol–water extract, and in butanol and methyl tert-butyl ether fractions using HPLC with on-line radical scavenging detection. After multi-step fractionation of these fractions five compounds possessing radical scavenging activity were purified and their structures were elucidated by NMR and MS as 5,6-dihydroxy-7,4′-dimethoxyflavone (syn. ladanein), 7-O-β-glucopyranosyl luteolin, 7-O-β-glucuronyl luteolin, verbascoside and forsythoside B. Their activities were tested in off-line DPPH and ABTS+ free radical scavenging assays, and compared with the antioxidants rosmarinic acid and Trolox.

Improving meat quality through natural antioxidants

Nowadays, consumers are demanding more natural foods, obliging the industry to include natural antioxidants in foods. Natural antioxidants have been used instead of synthetic antioxidants to retard lipid oxidation in foods to improve their quality and nutritional value. This review discusses some aspects of recent research on antioxidant activity of plant extracts and natural compounds to improve meat quality. Many herbs, spices, and their extracts have been reported as having high antioxidant capacity, such as some plants of the Lamiaceae family, e.g., oregano (Origanum vulgare L.), rosemary (Rosmarinus officinalis L.), and sage (Salvia officinalis L.). The antioxidant activity of these plants is attributed to their phenolic compound content, which includes volatile compounds also known as essential oils. Several factors that cause some differences on the antioxidant activity of plant extracts include: type of solvent used during extraction, measurement method, and number of samples. Some studies have demonstrated that shelf-life and meat quality can be improved by using natural antioxidants in some stages of meat production. The main effects of these compounds are reducing microbial growth and lipid oxidation during storage. Nevertheless, more research is needed to determine antimicrobial activity of natural antioxidants in meat during storage, identify the main metabolic pathway of these compounds, and its effect on other meat quality parameters.

마디풀 추출물의 Pancreatic Lipase 저해 및 항산화 활성 평가

As part of our continuing search for novel bioactive natural products, antioxidant and pancreatic lipase inhibitory activities of the aqueous ethanolic extract of Polygonum aviculare were investigated. In addition, the total phenolic content was quantified by a spectrophotometric method. The antioxidant properties of the extract were evaluated by radical scavenging assays such as DPPH and radicals. The anti-obesity efficacy of P. aviculare extract was tested by porcine pancreatic lipase assay. All tested samples showed a dose-dependent pancreatic lipase inhibitory and radical scavenging activities. In terms of the value, the ethyl acetate (EtOAc) soluble portion was most potent than other solvent soluble portions. The results suggested that P. aviculare could be considered as a new potential source of natural antioxidant and anti-obesity agent for food, nutraceutical, cosmetics industries.

Evaluation of Invitro and Invivo Antioxidant Activity of Oscillatoria annae

In the present study, the ethanol extract of Oscillatoria annae is evaluated for invitro and invivo antioxidant activity. The extract exhibited concentration dependendent 1, 1-diphenyl -2picryl-hydrazyl (DPPH), nitric oxide and hydroxyl radical scavenging activity with IC50 values of 80 μg/ml, 220μg/ml and107.5μg/ml. Further, the protective effect of ethanol extract of Oscillatoria annae against carbon tetrachloride induced oxidative damage was evaluated in albino wistar rats. The results of the Invivo study revealed that, pretreatment with ethanol extract of Oscillatoria annae in doses 200mg/kg and 400mg/kg orally enhanced the tissue superoxide dismutase (SOD), Catalase (CAT), glutathione peroxidase (GPx), Glutathione (GSH) and Glutathione reductase (GR). The results obtained in the present study indicate that ethanol extract of Oscillatoria annae can be a potential source of natural antioxidant activity.

Comprehensive evaluation of natural antioxidants and antioxidant potentials in Ziziphus jujuba Mill. var. spinosa (Bunge) Hu ex H. F. Chou fruits based on geographical origin by TOPSIS method

Technique for Order Performance by Similarity to Ideal Solution (TOPSIS) method was used to comprehensively evaluate total natural antioxidants and antioxidant activities in Ziziphus jujuba Mill. var. spinosa (Bunge) Hu ex H. F. Chou fruits based on geographical origin. Correlations between natural antioxidants, antioxidant activities and geographical conditions were investigated. TOPSIS evaluation showed that the fruits from Ningxia possess the largest amount of natural antioxidants and antioxidant activities among other samples. Correlation analyses indicated that both altitude and annual precipitation exert profound effects on natural antioxidant levels. Moreover, the fruits exhibited significant DNA damage protection activity and in vitro antiradical potentials. In particular, the fruits from Ningxia, Gansu and Shaanbei which were grown in the semi-arid regions of loess plateaus showed fairly higher antioxidant activities. To a certain degree, this study concludes that the fruits in arid harsh and high-altitude areas can accumulate higher levels of natural antioxidants and display stronger antioxidant activities.

Variation in the uric acid transporter gene SLC2A9 and its association with AAO of Parkinson's disease.

Based on the observed inverse association between hyperuricemia and Parkinson's disease (PD) risk, the natural antioxidant activity of uric acid has been suggested to play a protective role. SLC2A9 has been indicated as the most effective of all uric acid transporters, and SLC2A9 variants have been shown to influence circulating uric acid levels. With this study, we aimed to test the association between such SLC2A9 polymorphisms and age at onset (AAO) of PD. Variants rs733175, rs737267, rs1014290, and rs6449213 within SLC2A9 were genotyped in 664 PD individuals from three European centers. The effect of each polymorphism on AAO was estimated within each center using a linear regression model adjusted for gender and genotype at the other SNPs and assuming an additive genetic model. Results across centers were combined using inverse-variance weighted fixed-effect meta-analysis. The minor allele of rs1014290, previously shown to be associated with lower serum uric acid levels, was found to be associated with a lower AAO of PD (pooled estimate -4.56 years; 95% CI -8.13, -1.00; p=0.012). The association remained significant after adjustment for multiple comparisons and was highly consistent across centers (heterogeneity, I (2) 0%). No gender differences were observed. Our study suggests that SLC2A9 genetic variants influence age of onset of Parkinson's disease.

The kinetic characteristics of natural antioxidants in vegetable oils

The total content and activity of natural antioxidants of the phenol type in coconut, palm, corn, and rice oils were measured by the chemiluminescent method. The existence of antioxidants of two types in palm and rice oils was shown. The synergistic action of citric acid in the presence of tocopherol was observed for the example of coconut oil.

Isolation, identification and activity of natural antioxidants from costmary (Chrysanthemum balsamita) cultivated in Lithuania

Abstract The sweet, minty-lemony leaves of costmary ( Chrysanthemum balsamita ) are used for salads and tea, and as flavourings in meats, sausages, cakes and ale. In this study, the extracts isolated from costmary aerial parts were investigated as antioxidants in rapeseed oil and as free radical-scavengers in DPPH and ABTS + assays. It was found that costmary extracts and their fractions were weak antioxidants in rapeseed oil; however, some fractions were active in scavenging synthetic free radicals. Crude methanol–water extract, its tert -butyl methyl ether and butanol fractions were the most effective in DPPH assay by scavenging 87.0%, 86.9% and 86.4% of radicals present in the reaction, respectively. Several active compounds were detected in these fractions, using HPLC with on-line radical-scavenging detection. After multi-step fractionation of these fractions, four radical-scavenging constituents were isolated and their properties were assessed by DPPH (antiradical power, ARP, calculated as an inverse value of the effective concentration, 1/EC 50 ) and ABTS + (Trolox equivalent antioxidant capacity, TEAC 6min ) free radical-scavenging assays. The following structures were elucidated by NMR and MS: 5- O -caffeoylquinic acid (ARP = 3.85; TEAC 6min = 0.60), 3,5- O -dicaffeoylquinic acid (ARP = 6.25; TEAC 6min = 1.16), 5,7,4′-trihydroxy-3′,8-dimethoxyflavone (ARP = 0.03) and 5,7,3′,4′-tetrahydroxy-3,8-dimethoxyflavonol (ARP = 3.79; TEAC 6min = 1.50).

Prunus armeniaca L (apricot) protects rat testes from detrimental effects of low-dose x-rays

Exposure to low x-ray doses damages the spermatozoa, mainly by late-onset (ie, after 3 months) oxidative stress. Antioxidants ameliorate oxidation and prevent tissue damage. Prunus armeniaca L (apricot), rich in carotenoids and vitamins, is a potent natural antioxidant. We hypothesized that an apricot-rich diet might ameliorate the detrimental effects of low-dose x-rays on testis tissue. A 20% apricot diet was composed isoenergetically to the regular rodent diet. The total phenolic content, reducing power, and antioxidant capacity of both diets were determined. Sprague-Dawley rats received apricot-rich diets before and after x-ray exposure. Regular diets were given to controls. Rats were exposed to 0.2 Gy x-rays at the eighth week and were euthanized at the 20th postexposure week. Testicular oxidative status was determined by tissue thiobarbituric acid-reactive substances, reduced glutathione, superoxide dismutase, and catalase activities. For histologic evaluation, qualitative and quantitative microscopic determinations were performed, and Leydig and Sertoli cell counts and Johnsen scores were measured. The control diet group had significant testicular oxidative stress and mild tissue deterioration. Leydig and Sertoli cell counts, tubule diameters, and Johnsen scores were significantly decreased in the exposure groups. Apricot-rich diet significantly ameliorated the oxidative status and prevented the damage in tubular histology. The protective effects were prominent when the diet was maintained throughout the time course and were partially protected when the diet was initiated after exposure. The natural antioxidant activity of apricot ameliorates the delayed detrimental effects of low-dose irradiation on testis tissue. The high total antioxidant capacity of the apricot deserves further investigation.

Antigenotoxic activity and antioxidant properties of organic and aqueous extracts of pequi fruit (Caryocar brasiliense Camb.) pulp

The daily consumption of natural antioxidants protects against oxidative damage caused by reactive oxygen species (ROS), including DNA damage, and can reduce the risk of cancer, atherosclerosis and other degenerative diseases. The pulp of pequi (Caryocar brasiliense Camb.) fruit, a tree native to the Brazilian savannah, contains several compounds with antioxidant properties, including carotenoids, vitamin C, phenolic compounds such as flavonoids, saponins and tannins, and essential oils. In this work, we examined the ability of organic and aqueous extracts of pequi fruit pulp to protect against the genotoxicity induced by two antineoplastic drugs, cyclophosphamide (CP) and bleomycin (BLM). Micronucleus tests with mouse bone marrow cells and single-cell gel electrophoresis (comet assay) with peripheral blood leukocytes were used to examine the effects of CP and BLM, respectively. The antioxidant activity of the extracts was assessed by measuring lipid peroxidation with the TBARS method in mouse plasma. The fruit pulp extracts had no clastogenic or genotoxic effects in the cells studied, but both extracts protected against oxidative DNA damage caused by BLM or CP, indicating an ability to inhibit chemical mutagenesis in vivo. However, the protective effect against oxidative DNA damage depended on the dose of extract used. At the doses tested, the aqueous extract enhanced lipid peroxidation in mice of both sexes, especially in males. In contrast, the organic extract enhanced lipid peroxidation only in male mice, with no significant effect in females. These results suggest that, with adequate adjustment of the dose, an organic extract of pequi fruit pulp could be a useful dietary supplement with natural antioxidant activity, at least in females.

In Vitro Methods of Assay of Antioxidants: An Overview

With the current upsurge of interest in the function, measurement of efficacy and use of natural antioxidants, testing of antioxidant activity has received much attention. Several methods are being used, both in vitro and in vivo, to determine the antioxidant activity of natural antioxidants. Although, there is a great multiplicity of the methods used for the determination of antioxidant activity, there is no approved standardized in vitro method to evaluate the antioxidants of interest. This article presents a critical review of the various in vitro methods used for the determination of antioxidant activity and their merits and limitations.

New examples of the involvement of air oxygen in chemical reactions in solution

Two different processes, oxidation of the simplest alkylarenes in aqueous solutions and assessment of antiradical activity of natural antioxidants in blood serum by the rate of formation of fluorescing products from fluorescein dibutyrate, are characterized from a common viewpoint of the involvement in the reactions of air oxygen dissolved in the reaction medium.

How To Standardize the Multiplicity of Methods To Evaluate Natural Antioxidants

A great multiplicity of methods has been used to evaluate the activity of natural antioxidants by using different techniques of inducing and catalyzing oxidation and measuring the end point of oxidation for foods and biological systems. Antioxidant in vitro protocols for foods should be based on analyses at relatively low levels of oxidation under mild conditions and on the formation and decomposition of hydroperoxides. For antioxidant in vivo protocols, widely different methods have been used to test the biological protective activity of phenolic compounds. Unfortunately, many of these protocols have been based on questionable methodology to accurately measure oxidative damage and to assess relevant changes in biological targets. Many studies testing the ex vivo activity of phenolic compounds to inhibit human low-density lilpoprotein (LDL) oxidation have been difficult to evaluate because of the structural complexity of LDL particles and because a multitude of markers of oxidative damage have been used. Although studies with animal models of atherosclerosis have demonstrated the antioxidant effect of phenolic compounds in delaying the progress of this disease, human clinical trials of antioxidants have reported inconsistent and mixed results. Complex mixtures of plant polyphenols have been shown to be absorbed to varying degrees as metabolites in the intestine, but little is known about their interactions, bioavailability, and their in vivo antioxidant activity. Several metabolites identified in human plasma after consuming flavonoids need to be tested for possible nonantioxidant activities. More research and better-designed human studies are required to clarify the complex questions of bioavailability of polyphenols and the factors affecting their in vivo activities. Until we know what relevant in vivo activities to measure, any claims on the biological and health protective effects of natural polyphenolic compounds in our diet are premature.

In Vitro Activity of Vitamins, Flavonoids, and Natural Phenolic Antioxidants Against the Oxidative Deterioration of Oil-Based Systems

It is well-known, that lipid antioxidants can retard the oxidative rancidity of foods caused by atmospheric oxidation, and thus protect oils, fats, and fat-soluble components from their quality degradation. In the last few years, much emphasis has been put on the promotion and use of natural antioxidants, commonly occurring in many fruits and vegetables and thereby produced from various natural extracts. This review gives a summary of previously reported work together with more recent trends in the field of natural antioxidants. Focus is given on the mechanism of actions and the inhibitory effect of certain vitamins against the oxidative degradation of oil-based systems. Moreover, the use of natural phenolics (flavonoids, olive-oil penolics, herb extracts etc.) as antioxidants in numerous lipid food applications is discussed.