A study of the antioxidant capacity of oak wood used in wine ageing and the correlation with polyphenol composition

The antioxidant capacity of oak wood used in the ageing of wine was studied by four different methods: measurement of scavenging capacity against a given radical (ABTS, DPPH), oxygen radical absorbance capacity (ORAC) and the ferric reducing antioxidant power (FRAP). Although, the four methods tested gave comparable results for the antioxidant capacity measured in oak wood extracts, the ORAC method gave results with some differences from the other methods. Non-toasted oak wood samples displayed more antioxidant power than toasted ones due to differences in the polyphenol compositon. A correlation analysis revealed that ellagitannins were the compounds mainly responsible for the antioxidant capacity of oak wood. Some phenolic acids, mainly gallic acid, also showed a significant correlation with antioxidant capacity

Role of antioxidant supplementation and exercise regimen in handling oxidative stress from natural PM2.5 exposure due to boreal forest fire

Thesis (M.S.) University of Alaska Fairbanks, 2019Particulate matter 2.5 (PM2.5) exposure induces oxidative stress that causes many negative health outcomes such as cancer, cardiovascular disease and neurodegenerative disease. Research shows that dietary antioxidants and an up-regulated endogenous antioxidant response from exercise play key roles in the antioxidant defense against oxidative stress. This study is the first to use an animal model to investigate the cumulative effects of using lifestyle interventions of antioxidant supplementation (Arthrospira platensis) and exercise regimen on the antioxidant response before, during, and after ambient PM2.5 exposure. In a two-factorial, longitudinal design, sled dogs (n=48) were divided into four groups (exercise and supplemented, exercise, supplemented, and control) to (1) test the effects of exercise and antioxidant regimen on antioxidant response after one month of implemented exercise and supplementation protocol and (2) measure the antioxidant response of all groups during and after a natural forest fire event in 2015. Commercial assays for Total antioxidant Power (TAP) and the enzymatic antioxidant Superoxide Dismutase (SOD) were used as markers for the total antioxidant response and the endogenous response at all time points. During the forest fire, SOD was increased 5-10-fold over pre/post-exposure levels in all groups suggesting potential implication for using SOD as a marker for the acute response to environmental stress. TAP was increased in the exercise groups after one month of exercise protocol implementation, demonstrating the cytoprotective increase of antioxidants after repeated exercise.Chapter 1: Introduction -- 1.1 PM2.5 -- 1.2 Oxidative stress and exercise -- 1.3 Antioxidants -- 1.4 Significance and research hypothesis -- Chapter 2 The effects of spirulina supplementation and exercise regimen on the antioxidant response to PM2.5 exposure in sled dogs -- 2.1 Introduction -- 2.2 Materials and methods -- 2.2.1 Animals -- 2.2.2 Experimental design -- 2.2.4 Exercise -- 2.2.5 Blood sampling -- 2.2.6 Biochemical analyses -- 2.2.7 Statistics -- 2.3 Results -- 2.4 Discussion -- 2.5 Conclusions -- Chapter 3 Conclusions and future directions -- References

Total Antioxidant Activity in Normal Pregnancy

Objective: Pregnancy is a state, which is more prone for oxidative stress. Various studies report development of a strong defence mechanisms against free radical damage, as the pregnancy progresses. Aim of our study is to assess the antioxidant status by measuring the total antioxidant activity. Methods: Total antioxidant activity was assayed by Koracevic’ et al’s method, with the plasma of twenty five pregnant women (with normal blood pressure) as test group and twenty five age matched non-pregnant women as control group. All complicated pregnancies are excluded from the study. Results: Highly significant decline (P< 0.001) in antioxidant activity was observed in pregnant women with a value of 1.40 ± 0.25mmol/l, as compared to controls, 1.63 ± 0.21 mmol/l. Conclusion: Reduction in total antioxidant activity could be due to the fall in individual antioxidant levels. But several studies report an elevated enzymatic and non-enzymatic antioxidants during pregnancy. Any way total antioxidant activity is not a simple sum of individual antioxidants, but the dynamic equilibrium & cooperation between them. So inspite the rise in individual antioxidants , total antioxidant activity may be low. Further studies need to be done with antioxidant activity as a marker of complicated pregnancies like pregnancy induced hypertension

Morinda Lucida: Antioxidant and Reducing Activities of Crude Methanolic Stem Bark Extract

The antioxidant activity of Morinda lucida (Benth.) stem bark was investigated. Air dried stem bark of Morinda lucida was powdered and extracted with 95 % v/v methanol and the extract concentrated at 40oC using rotary evaporator. The total phenolic composition of methanolic extract of air - dried stem bark was estimated using spectrophotometric method. Phenolic composition was calculated to be approximately 80 %. Antioxidant activity of the extract was determined using its ability to prevent the oxidation of â-carotene. Ferric reducing ability of extract was also determined. Antioxidant and ferric reducing activities exhibited by plant extract were concentration dependent. Plant extract achieved a maximum antioxidant activity of 6% within 40minutes. The total phenolic content, antioxidant activity and reducing power of the extract had direct relationship

Paradoxical roles of antioxidant enzymes:Basic mechanisms and health implications

Reactive oxygen species (ROS) and reactive nitrogen species (RNS) are generated from aerobic metabolism, as a result of accidental electron leakage as well as regulated enzymatic processes. Because ROS/RNS can induce oxidative injury and act in redox signaling, enzymes metabolizing them will inherently promote either health or disease, depending on the physiological context. It is thus misleading to consider conventionally called antioxidant enzymes to be largely, if not exclusively, health protective. Because such a notion is nonetheless common, we herein attempt to rationalize why this simplistic view should be avoided. First we give an updated summary of physiological phenotypes triggered in mouse models of overexpression or knockout of major antioxidant enzymes. Subsequently, we focus on a series of striking cases that demonstrate “paradoxical” outcomes, i.e., increased fitness upon deletion of antioxidant enzymes or disease triggered by their overexpression. We elaborate mechanisms by which these phenotypes are mediated via chemical, biological, and metabolic interactions of the antioxidant enzymes with their substrates, downstream events, and cellular context. Furthermore, we propose that novel treatments of antioxidant enzyme-related human diseases may be enabled by deliberate targeting of dual roles of the pertaining enzymes. We also discuss the potential of “antioxidant” nutrients and phytochemicals, via regulating the expression or function of antioxidant enzymes, in preventing, treating, or aggravating chronic diseases. We conclude that “paradoxical” roles of antioxidant enzymes in physiology, health, and disease derive from sophisticated molecular mechanisms of redox biology and metabolic homeostasis. Simply viewing antioxidant enzymes as always being beneficial is not only conceptually misleading but also clinically hazardous if such notions underpin medical treatment protocols based on modulation of redox pathways

Antioxidant and Antitumor Activity of Indonesian Herbal Ingredients

The present study was to aimed to evaluated and compare in vitro antioxidant activities of 2 Indonesian herbal ingredients (A and B), determined total phenol content., cytotoxic and apoptosis induction activities on HL-60 cells. These data were providing some useful information for people healthy dietary and the new potential application of natural antioxidant containing food materials in functional foods and also as new cancer therapeutics promising candidates. The parameters were total antioxidant activity, amount of total cytotoxic effect on the growth of human promyelocytic leukemia cells (HL-60). Statistical comparison was perform with Student's t-test at p<0.05. The correlation coefficient (r2) between the parameters tested was established by regression analysis. The scavenging effect of extracts herbal on DPPH radicals increased from 0.3-1.5 mg/ml, where is sample A 14.33% to 64.29% and sample B 9.09% to 57.53% was obtained. High content of total phenol compounds were in sample A (21.72 mg GAE/g), lower amounts were in sample B (17.53 mg GAE/g). Apoptosis of HL-60 cells from the morphological changes side (chromatin condensation). Chromatin condensation, a specific and distinct feature of apoptotic cells, was found in the majority of treated cells. The results indicated that the cell death receptor pathway was involved in the apoptosis induced by Indonesian herbal extracts

Comparative Antioxidant Activity on the Ficus Benjamina and Annona Reticulata Leaves

Antioxidants can prevent free radical formation. Natural antioxidants found in many plants, such as Ficus benjamina and Annona reticulata. The study aimed to compare the antioxidant activity of extracts and fractions of Ficus benjamina and Annona reticulata leaves against 1,1-diphenyl-2-picrilhydrazyl. The steps of this study consist of extraction, fractionation with n-hexane, ethyl acetate and water, phytochemical screening, antioxidant activity determination, and comparing the IC50 values. Percentage scavenging activity of the extracts and fractions against DPPH was calculated to determine the antioxidant activity. The IC50 value of Ficus benjamina was 127.86 ppm for ethanolic extract, 94.01 ppm for water fraction, 115.48 ppm for ethyl acetate fraction, and 335.50 ppm for n-hexane fraction. The IC50 value of Annona reticulata was 274.31 ppm for ethanolic extract, 211.42 ppm for water fraction, 367.91 ppm for ethyl acetate fraction, and 741.08 ppm for n-hexane fraction. The results showed that the Ficus benjamina water fraction was the best antioxidant compared to other extract and fraction

Amperometric enzyme sensor to check the total antioxidant capacity of several mixed berries. comparison with two other spectrophotometric and fluorimetric methods

The aim of this research was to test the correctness of response of a superoxide dismutase amperometric biosensor used for the purpose of measuring and ranking the total antioxidant capacity of several systematically analysed mixed berries. Several methods are described in the literature for determining antioxidant capacity, each culminating in the construction of an antioxidant capacity scale and each using its own unit of measurement. It was therefore endeavoured to correlate and compare the results obtained using the present amperometric biosensor method with those resulting from two other different methods for determining the total antioxidant capacity selected from among those more frequently cited in the literature. The purpose was to establish a methodological approach consisting in the simultaneous application of different methods that it would be possible to use to obtain an accurate estimation of the total antioxidant capacity of different mixed berries and the food product

Effect of Steaming and Boiling on the Antioxidant Properties and Biogenic Amines Content in Green Bean (Phaseolus vulgaris) Varieties of Different Colours

Effects of boiling and steaming cooking methods were studied on total polyphenols, antioxidant capacity, and biogenic amines of three green bean varieties, purple, yellow, and green.The vegetables gave good values both for antioxidant capacity and for phenolics content, with the purple variety being the richest in healthful components. Both the heat treatments affected the antioxidant properties of these vegetables, with boiling that reduced the initial antioxidant capacity till 30%in the yellowvariety, having the same trend for total polyphenols, with the major decrement of 43% in the green variety. On the contrary, biogenic amines significantly increased only after boiling in green and yellow variety, while purple variety did not show any changes in biogenic amines after cooking. The steaming method showed being better cooking approach in order to preserve the antioxidant properties of green beans varieties and to maintain the biogenic amines content at the lowest level

In vitro assessment of antioxidant activity of Newbouldia laevis

Poverty, drug resistance and other factors including increasing difficulty in the control of mosquitoes (the vector of the causative organism of malaria), have led to a growing interest in phytochemical research. The antioxidant activity of Newbouldia laevis stem bark was investigated. Air dried stem bark of N. laevis was powdered and extracted with 95 % v/v methanol by maceration, and the extract concentrated at 40oC using rotary evaporator. The total phenolic composition of methanolic extract of air dried stem bark was estimated using spectrophotometric method. Antioxidant activity of the extract was evaluated on the basis of its ability to prevent the oxidation of _-carotene and the strength of its ferric reducing capacity also determined. Phenolic composition was calculated to be approximately 35%. Plant extract showed concentration - dependent antioxidant activity and ferric reducing power. Plant extract achieved a maximum antioxidant activity of 4% within 40 min. The total phenolic content, antioxidant activity and reducing power of the extract had direct relationship