Increase In Radical Scavenging Activity Research Articles

Investigation of novel radical scavenging mechanisms in the alkaline environment: Green, sustainable and environmentally friendly antioxidative agent(s)

Pharmaceutical and industrial utilization of synthetic chemicals has an immerse impact on the environment. In that sense, novel chemicals with potential for industrial application should be investigated for their behaviour in reactions with hydroxyl radical, simulating AOPs (Advanced Oxidation Processes). AOPs are known for being highly effective in wastewater management and natural water remediation. In this paper, exhaustive research on the radical scavenging activity of a newly synthesized coumarin derivative (4HCBH), as a representative of the series of coumarin-benzohydrazides with high antioxidative potential was conducted. This study took into consideration the pH value range significant for practically all living organisms (pH = 7.0–8.5). According to the experimentally obtained results, the 4HCBH showed an increase in radical scavenging activity, following the slight increase in pH values, which suggested that the formation of anionic form of 4HCBH is responsible for its antiradical activity. Further investigations led to the postulation of a novel mechanistic approach called Sequential Proton Loss Electron Transfer – Radical-Radical Coupling (SPLET-RRC), in which, by a series of steps, a new, stable compound was formed. Furthermore, it was demonstrated that the product generated through SPLET-RRC showed lower toxicity than the parent molecule.

Quality Attributes of Refrigerated Barhi Dates Coated with Edible Chitosan Containing Natural Functional Ingredients.

Edible chitosan coatings with natural functional ingredients were used to preserve quality attributes of fresh Barhi date fruit. Fruits were coated with chitosan and/or 1 and 2% olive cake extract (OCE) or orange peel extract (OPE). Both coated and uncoated fruits were stored at 4 °C for 4 weeks. A slight decrease in the pH and increase in acidity with storage was observed. However, when chitosan was mixed with OCE or OPE, an increase in pH was observed with a concomitant decrease in acidity. The phenolic content of the samples was decreased with time. However, coating the date with OCE or OPE significantly (p ≤ 0.05) increased the total phenolic with a concomitant increase in radical scavenging activity. The textural properties, particularly hardness, were better preserved in case of coated dates. The sensory evaluation data showed non-significant changes in the acceptability of the Barhi dates throughout the storage period. Chitosan-coating significantly (p ≤ 0.05) inhibited mold growth over time. Scanning electron microscope (SEM) imaging showed difference among different coatings. According to principal component analysis (PCA), OCE and OPE were found to have protective effects on fruit quality.

Exploring the antioxidant effects of peptides from almond proteins using PAni-Ag-GONC conjugated trypsin by improving enzyme stability & applications

Functionalized graphene oxide nano-sheets (PAni-Ag-GONC) were prepared and employed as carrier for covalent immobilization of trypsin. This low cost setting, which involves loading of high amount of enzyme on the matrix, displayed significantly enhanced thermo-stability and pH resistance. The nano-composite (NC) bound trypsin preserved 90% of activity whereas native trypsin retained only 44% of activity after 60 days of storage at a temperature of 4°C. Immobilized trypsin conserved 80.5% of activity even after its ten repeated uses. Almond protein hydrolysates prepared by native and conjugated enzyme was investigated for antioxidant activities and found that peptides resulted from NC bound trypsin displayed increase in radical scavenging activity (i.e. around 30% and 37% scavenging activity observed, respectively by native and NC bound trypsin from same concentration of peptides). This strategy provides a new approach for production of potential biopeptides which may be incorporated in drugs and functional food industries applying PAni-Ag-GONC based biocatalysis. Chemical compoundsTrichloroacetic acid (PubChem CID: 6421); Tris (hydroxymethyl)aminomethane (PubChem CID: 6503); Glycine (PubChem CID: 750); and 2,2′-diphenyl-1-picrylhydrazyl (PubChem CID: 74358); Nα- Benzoyl-DL-arginine 4-nitroanilide hydrochloride (PubChem CID: 2724371); Ammonium sulphate (PubChem CID: 6097028).

In vitro study on antioxidant activity of methanolic leaf extract of Cassia fistula Linn.

Background: The use of medicinal plants for maintaining good health is getting attention worldwide. Antioxidants play an important role to protect damage caused by oxidative stress. In the present study methanolic extracts of Cassia fistula was determined using DPPH for its antioxidant activity. Phytochemical investigation confirmed the presence of bioactive ingredients in the extract.Methods: The antioxidant activity of methanolic extract of Cassia fistula was evaluated using DPPH free radical assay. DPPH (1,1-diphenyl-2-picrylhydrazyine) free radical analysis is one of the accurate and frequently employed method for evaluating antioxidant activity.Results: The methanolic extracts showed increase in radical scavenging activity as concentration increases. The IC50 values were calculated for the methanolic extract. Ascorbic acid was used as control. Cassia fistula exhibited IC 50 of 79.42µg/ml.Conclusions: Scientific evidence suggests that antioxidants reduce the risk for chronic diseases including cancer and heart disease and infectious diseases. Further evaluation of pharmacological activities of Cassia fistula may prove useful in treatment of cancer and heart diseases.

Pre‐sowing seed treatment with cold plasma and electromagnetic field increases secondary metabolite content in purple coneflower (Echinacea purpurea) leaves

The effects of seed treatment with cold plasma (2–7 min), vacuum (7 min), and electromagnetic field (5–15 min) on Echinacea purpurea germination and performance are studied. All treatments induce faster germination but did not change the final germination percentage, except the decrease evoked by vacuum treatment. The plants grown from all groups of treated seeds have larger height, develop more leaves, some treatments increase root weight. The content of vitamin C and phenolic acids in extracts of plant leaves from the treated groups is substantially higher in comparison to the control, so that the amount of cichoric acid per plant increased up to 3.8‐fold, and amount of vitamin C per plant – up to 1.9‐fold. Seed treatments induce large increase in radical scavenging activity (up to 114%) in leaf extracts.

Mechanical hulling and thermal pre-treatment effects on rapeseed oil antioxidant capacity and related lipophilic and hydrophilic bioactive compounds

In this study, the effect of rapeseed mechanical hulling and thermal pre-treatment by microwaves (from 2 to 10 min with 2-min intervals, 800 W) and roasting (from 20 to 100 min with 20-min intervals, 165 °C) on the content of phytochemicals in the oil was investigated. Results showed that both pre-treatments applied differentiated the oils in terms of the content of bioactive compounds. In general, oils pressed from hulled and thermally pre-treated seeds contained higher content of tocopherols, PC-8 and phytosterols, while oils pressed from non-hulled and pre-processed seeds had significantly higher concentration of polyphenols. Both microwaving and roasting contributed to an increase of antioxidant capacity of studied oils. The increase of radical scavenging activity of oils was seen mainly in hydrophilic fraction of oil, which was highly positively correlated with the amount of canolol formed during seeds heating.

Effect of acid pretreatment and the germination period on the composition and antioxidant activity of rice bean (Vigna umbellata).

This research evaluated effect of germination period and acid pretreatment on chemical composition and antioxidant activity of rice bean sprouts. Moisture, total phenolics, reducing sugar and B vitamins (thiamine, riboflavin, and niacin) content of steamed sprouts increased with increasing germination time (p⩽0.05). Pretreatment with 1% (w/v) citric acid for 6h significantly increased the total phenolic content. The 18-h-germinated rice beans showed the highest crude protein content, as determined using the Kjeldahl method. During germination, acid pretreatment led to a significant decrease in the intensity of the 76-kDa band. Germination caused a significant increase in radical scavenging activity and ferric reducing antioxidant power, especially in sprouts from citric acid-treated seeds. The antioxidant activities of the ethanolic extracts from both pretreated beans and the control were 1.3-1.6 times higher than those obtained from the water extracts. Major phenolics found in both 0-h and 18-h-germinated rice beans were catechin and rutin.

Phytochemical and antioxidant evaluation of <i>Moringa oleifera</i> (Moringaceae) leaf and seed

Moringa oleifera , a plant with a wide range of medicinal, nutritional and economic benefits was examined for phytochemicals and evaluated for antioxidant activities. Phytochemical tests, total phenol and flavonoid contents were determined using standard procedures. Antioxidant activities of the methanol extracts and fractions were evaluated using the 2,2-diphenyl-1-picryl hydrazyl radical scavenging assay. The leaf and seed contained alkaloids, saponins, phenols and flavonoids. The ethyl acetate fraction of the leaf contained significantly (P < 0.05) more phenol (78.67 ± 3.40 mgGAE/g Extract) than the crude extract and petroleum ether fraction with total phenolic content of 58.00 ± 1.00 and 26.17 ± 3.88 mg GAE/g Extract respectively while the seed extract had a total phenol content of 17.67 ± 2.02 mg GAE/g Extract. The petroleum ether fraction of the leaf was found to contain significantly (P < 0.05) more flavonoid (161.33 ± 19.05 mgQE/g Extract) than the other samples (31.73 ± 2.66, 30.20 ± 10.14 and 20.73 ± 4.16 mgQE/g Extract for the crude leaf extract, leaf petroleum ether fraction and seed extract respectively). The leaf and seed extracts exhibited remarkable and concentration-dependent increase in radical scavenging activities with IC50 values ranging from 5.72-42.56 μg/mL. The results therefore support the use of Moringa oleifera as a natural plant antioxidant by preventing free radical damage. Keywords : Moringa oleifera ; Antioxidant; Phytochemical, Free radical

Kefir Properties Prepared with Goat Milk and Black Rice (Oryza sativa L.) Extract and its Influence on the Improvement of Pancreatic beta-Cells in Diabetic Rats

This study were to evaluate the properties of kefir prepared with a combination of goat milk and black rice extract and its influence on the improvement of beta-cells in streptozotocin-nicotinamide (STZ-NA) -induced diabetic rats. Kefir was divided into four groups using the following materials: goat milk (GM), goat milk + inulin (GM + IN), goat milk + black rice extract (1:1)(GM + BRE), and goat milk + black rice extract + inulin (GM + BRE + IN). After fermentation, all kefir were stored at 4 degrees C for 1 and 7 d, and then were analyzed for microbial, chemical properties and antioxidant activity. Furthermore, three kinds doses of kefir combination from goat milk and black rice extract (GM + BRE) were administered to rats. Thirty male rats 8-12 weeks old were divided into 6 groups: 1) negative control (normal rats); 2) positive control (untreated diabetic rats); 3) diabetic rats fed kefir ; 4 > diabetic rats fed kefir (2.0 ml); 5) diabetic rats fed kefir (4.0 ml), and 6) diabetic rats received glibenclamide. After 28 d experiment, the rats were sacrificed for sampling pancreatic tissues. Subtitution of goat milk with black rice extract in kefir fermentation could decrease their pH and increase in radical-scavenging activity. Inulin addition able to increase (p < 0.05) in radical-scavenging activity of kefir. Alcohol and total phenolic contents of kefir increased (p < 0.05) after 7 d of storage, while the pH decreased. To improve insulin-producing pancreatic beta-cells in diabetic rats, it was required at least 2.0 ml dose of kefir combination from goat milk and black rice extract to achieve similar effect to glibenclamide as antidiabetic agent.

Abrus precatorius Leaves: Antioxidant Activity in Food and Biological Systems, pH, and Temperature Stability.

Natural antioxidants present in foods and other biological materials have attracted considerable interest because of their presumed safety and potential nutritional and therapeutic effects. Antioxidant constituents of plant materials act as radical scavengers and convert the radicals to less reactive species. Abrus precatorius (AP) was analyzed for its proximate and phytochemical composition. The leaves were extracted with methanol (ME) and analyzed for antioxidant activity by radical scavenging method, reducing power, ferric reducing capacity, and in vitro inhibition of Fenton's reagent-induced oxidation in oil emulsion and microsomes. In addition, the effect of temperature (100°C, 15, and 30 min) and pH (4.5, 7, and 9) C on the antioxidant activity of ME was investigated. The leaves were rich in total polyphenols, flavonoids, β-carotene, glutathione, α-tocopherol, and ascorbic acid. The ME exhibited varying degree of antioxidant activity in a dose-dependent manner. The AP exhibited more inhibition of oxidation in microsomes (73%) than compared to oil emulsion (21%). Heat treatment resulted in an increase of radical scavenging activity of extract (28% to 43%). At pH 4.5 the extract exhibited more antioxidant activity and stability compared to pH 7 and 9. Data indicates that potential exists for the utilization of Abrus precatorius as a natural antioxidant.

사료 내 항산화원으로서 커피박 첨가가 닭의 사양성적, 혈액생화학성상 및 항산화 작용에 미치는 영향

본 연구는 커피박 첨가 사료가 육계의 사양 성적, 면역 장기 무게, 혈액성상 및 항산화 방어 작용에 미치는 영향에 대하여 조사하기 위하여 실시되었다. 실험 설계로서 3일령 육계 162수를 각 처리구당 54수씩(n=6, 케이지당 9수) 대조군(CON), 커피박 0.5%(CM0.5) 및 1.0%(CM.0) 3 처리군에 완전임의 배치하여 35일령까지 사양 시험을 실시하였다. 커피박 분말은 육계 후기 사양 기간(2~35일령) 동안에 첨가하여 급여하였다. In vitro radical 소거능 분석(DPPH 방법) 결과, 커피박 추출물은 매우 높은 radical 소거능(RSA)을 보였다. 사양 시험 결과, 커피박 0.5 및 1.0% 참가 급여는 체중, 증체량, 사료 섭취량 및 사료 요구율에 따른 부정적 영향이 없는 것으로 나타났다. 또한 간, 비장 및 F-낭 등 면역 관련 장기 무게 역시 커피박 첨가에 따른 영향을 받지 않았으나, 흉선의 무게는 커피박 첨가군에서 유의적으로(P<0.05) 증가되었다. 혈액 생화학 성상에서도 glucose, total protein, triglyceride, cholesterol 등은 차이가 없었으나, albumin은 커피박 첨가군에서 유의하게(P<0.05) 증가하였다. 소장점막세포 및 간조직에서 SOD, GPX 및 GST와 같은 항산화 효소의 활성도 및 GSH 함량은 커피박 첨가에 따른 영향을 받지 않는 것으로 나타났다. 그러나 간세포의 microsome 조직에서 지질과 산화도(MDA)는 커피박 첨가에 따라 감소되었으며, CM0.5 군에서 대조군에 비해 현저히(P<0.05) 감소되었다. 결론적으로 0.5~1.0% 수준의 커피박 첨가 급여는 육계의 사양 성적에 부정적인 영향을 미치지 않았으며, 오히려 간 조직의 지질과산화를 억제하여 체 조직에서 항산화력을 증가시키므로 육계 사료 내 천연 항산화 소재로서 이용이 가능할 것으로 사료된다. The effects of dietary supplementation of dried coffee meal (CM) on growth performance, blood biochemical profiles, the weights of immune-related organs, and the antioxidant defense system in broiler chicks were examined. A total of 162, 3-day-old male broiler chickens were assigned to three dietary groups: control group (CON), control diet added with 0.5% CM (CM0.5), and control diet added with 1.0% CM (CM1.0). In vitro antioxidant activity test, coffee extracts showed concentration-dependent increase in radical scavenging activity. Dietary addition of 0.5 and 1.0% of CM did not have negative effects on growth performance and feed conversion during the experimental periods, whereas dietary CM significantly (P<0.05) increased the relative weight of thymus without changes in the other organ weights. In addition, birds fed the diet supplemented with CM (0.5 and 1.0%) significantly increased blood albumin without affecting other components including glucose, triglyceride and cholesterol compared with those fed control diet. In antioxidant defense system, the specific activities of superoxide dismutase, glutathione peroxidase and glutathione S-transferase and the level of glutathione in the small intestine and liver were not affected by dietary supplementation of CM. However, hepatic lipid peroxidation in birds fed the diet supplemented with 0.5% CM was significantly (P<0.05) decreased compared with that in control birds. In conclusion, dietary supplementation of CM(0.5~1.0%) has potential for use as a natural antioxidant source without negative effect on growth performance in broiler chickens.

Comparative evaluation of selected strains of lactobacilli for the development of antioxidant activity in milk

Species of Lactobacillus are widely used as starter cultures in the dairy industry and have been reported to play a significant role in the production of bioactive peptides in fermented dairy products. The aim of the present study was to screen selected strains of Lactobacillus for their ability to generate antioxidant activity during the fermentation of milk and to correlate their proteolytic activity with antioxidative peptide production. Skim milk fermented with 19 strains of Lactobacillus from ten species was evaluated for antioxidant activity by 2, 2′-azinobis (3-ethylbenzothiazoline-6-sulphonic acid) decolourization assay. The whey fraction of fermented skim milk showed radical scavenging activity ranging from 0.12 to 0.49 mmol·L−1 Trolox equivalent antioxidant capacity. The proteolytic activity of the different strains ranged from 0.40 to 2.25 mmol·Leu·L−1. Seven strains including Lactobacillus delbrueckii subsp. bulgaricus NCDC08, Lactobacillus plantarum NCDC25, Lactobacillus casei subsp. casei NCDC17, Lactobacillus rhamnosus NCDC24, Lactobacillus paracasei subsp. paracasei NCDC63, Lactobacillus fermentum NCDC141 and Lactobacillus helveticus NCDC288 exhibited a positive correlation between antioxidant and proteolytic activity. On hydrolysis of casein with cell-free extract from these seven strains, L. rhamnosus NCDC24, L. casei subsp. casei NCDC17 and L. paracasei subsp. paracasei NCDC63 showed a significant (P < 0.05) increase in radical scavenging activity. The low molecular weight peptides (<3 kg·mol−1) represented 60–70% of the total radical scavenging activity for these three strains. The development of antioxidant activity was found to be strain specific and that these strains of Lactobacillus may be useful in developing functional foods to combat oxidative stress.

ORGANIC SWEET CHERRY DEHYDROFREEZING AND QUALITY: CULTIVAR SELECTION BRIDGED WITH INNOVATIVE TECHNOLOGY

Four cultivars of organic sweet cherry were considered in this work. The influence of both a steam and an osmo-blanching step applied to fruit halves before freezing, on colour and on radical-scavenging activity related to the recovery of total phenols and anthocyanins was studied. A 60% (wt/wt) glucose-fructose mixture (2:1) was used for the osmo-blanching, carried out at 87°C for 3 min. Fruit blanching induced a significant recovery increase of total anthocyanins, with a consequently significant increase of radical-scavenging activity. Osmo-blanching proved to be more effective than steam-blanching in 'Adriana'.

Production of enzymatic hydrolysates with antioxidant and angiotensin-I converting enzyme inhibitory activity from pumpkin oil cake protein isolate

Protein isolate from pumpkin oil cake (PuOC PI) was hydrolysed by alcalase, flavourzyme and by sequential use of these enzymes, respectively, and the antioxidant properties and angiotensin-I converting enzyme (ACE) inhibitory activities of hydrolysates were evaluated. Under the same reaction conditions, alcalase hydrolysates showed a higher degree of hydrolysis (DH) than did flavourzyme hydrolysates. The highest DH’s by individual enzymes were 53.23 ± 0.7% and 37.17 ± 1.05%, respectively, both at 60 min. The increase of radical scavenging activity (RSA) in hydrolysates was positively correlated with the increase of DH, for both enzymes, though hydrolysates with flavourzyme showed two- or three-fold lower RSA than with alcalase. The highest bioactive potential was determined in the alcalase hydrolysate at 60 min, with RSA being 7.59 ± 0.081 mM TEAC/mg and ACE-inhibitory activity 71.05 ± 7.5% (IC 50 = 0.422 mg/ml). When this hydrolysate was further hydrolysed by flavourzyme, DH increased up to 69.29 ± 0.9%, but lower RSA (4.82 ± 0.21 mM TEAC/mg) and ACE-inhibitory activity (55.81 ± 6.196%) were determined in the final hydrolysate. This study suggested that the PuOC proteins could be converted into protein hydrolysates with antioxidant and ACE-inhibitory activities by enzymatic hydrolysis. Alcalase was shown as promising enzyme in further development of bioprocesses for the production of new bioactive food ingredients.

PH-Dependent Radical Scavenging Capacity of Green Tea Catechins

The effect of pH on the radical scavenging capacity of green tea catechins was investigated using experimental as well as theoretical methods. It was shown that the radical scavenging capacity of the catechins, quantified by the TEAC value, increases with increasing pH of the medium. Comparison of the pKa values to theoretically calculated parameters for the neutral and deprotonated forms indicates that the pH-dependent increase in radical scavenging activity of the catechins is due to an increase of electron-donating ability upon deprotonation. The data also reveal that the radical scavenging activity of the catechins containing the pyrogallol (or catechol) and the galloyl moiety over the whole pH range is due to an additive effect of these two independent radical scavenging structural elements. Altogether, the results obtained provide better insight into the factors determining the radical scavenging activity of the catechins and reveal that the biological activity of green tea catechins will be influenced by the pH of the surrounding medium or tissues.

Monitoring lipid oxidation events at frying temperatures through radical scavenging assays

This communication proposes an alternative approach for monitoring oils during thermal stress at frying temperatures through radical scavenging assays. Oxidation events for extra virgin olive, pomace, sesame, sunflower, soybean, corn and of a commercial blend of oils are followed through the DPPH assay during heating at 100, 150 and 190?C. Radical scavenging activity decrease expressed as trolox equivalent antioxidant capacity (?TEAC, mmol trolox kg-1 oil) is found to be linearly related to increases in total oxidation (?TOTOX) values. This relationship is valid down to a certain - ?TEAC value cutoff that is different for different oils. Considerable consumption of antioxidants demonstrated by high -?TEAC values renders the linear relationship invalid indicating that antioxidants cannot control late events of oxidative damage. Radical scavenging activity is found to increase upon sesame oil heating in contrast to all other oils. It is postulated that sesamolin, a phenolic antioxidant, decomposes during heating to the more potent antioxidant sesamol accounting for the increase of radical scavenging activity upon heating. This paper demonstrates prospects of radical scavenging activity assays as a tool for monitoring oxidation events during frying and warrants further research and evaluation.

Changes in the antioxidant properties of protein solutions in the presence of epigallocatechin gallate

β-Casein and α-casein showed radical-scavenging activities in aqueous solution, whereas bovine serum albumin (BSA), α-lactalbumin and β-lactoglobulin showed much weaker antioxidant activity, when assessed by the 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) radical-scavenging assay. However, β-casein and α-casein showed reduced antioxidant activity after storage at 30 °C. An increase in radical-scavenging activity and a fall in fluorescence of the protein component were evident after 6 h, when BSA, β-lactoglobulin or casein were mixed with EGCG, and excess EGCG was removed, indicating the formation of a complex with this protein on mixing. Storage of all the proteins with EGCG at 30 °C caused an increase in the antioxidant activity of the isolated protein component after separation from excess EGCG. This showed that EGCG was reacting with the proteins and that the protein-bound catechin had antioxidant properties. The reaction of EGCG with BSA, casein and β-lactoglobulin was confirmed by the loss of fluorescence of the protein on storage, and the increase in UV absorbance between 250 and 400 nm. The increase in antioxidant activity of BSA after storage with EGCG was confirmed by the ferric reducing antioxidant potential (FRAP) and the oxygen radical antioxidant capacity (ORAC) assays.

Grape Seed and Skin Extracts Inhibit Platelet Function and Release of Reactive Oxygen Intermediates

Red wine and purple grape juice contain polymeric flavonoids with antioxidant properties believed to be protective against cardiovascular events but the alcohol and sugar content of these beverages has curtailed their medicinal use. Acute cardiac events are also associated with enhanced inflammation and thrombosis. In this study, the extracts from grape skins or seeds were examined for their anti-inflammatory properties and effect on platelet release of reactive oxygen intermediates. Incubation of platelets with seed or skin extract led to a decrease in platelet aggregation from 68.8+/-19.8% to 45+/-3.6% for seeds and to 27+/-7.2% for skin, respectively (P<0.05). Platelet incubation with grape skin or seed extracts led to a marked decrease in superoxide release from 73+/-6.2 to 2+/-3.4 for grape seeds and to 0.33+/-0.57 for grape skin (chemilum. units; P<0.05) as well as a significant increase in radical-scavenging activity, decrease in reactive oxygen species release by confocal microscopy, and enhanced platelet NO was measured using an NO-sensitive microelectrode. These effects were dose dependent for both grape extracts. Coincubation with seeds and skins led to additive inhibition of platelet aggregation, enhanced NO release, and prevented superoxide production. Incubation with seed or skin extracts led to an immediate attenuation of release of the inflammatory mediator, soluble CD40 ligand. Thus, the extracts from purple grape skins and seeds inhibit platelet function and platelet-dependent inflammatory responses at pharmacologically relevant concentrations. These findings suggest potentially beneficial platelet-dependent antithrombotic and anti-inflammatory properties of purple grape-derived flavonoids.