Source Of Antioxidant Compounds Research Articles

Chemical composition, antioxidant and antifungal potential of Melaleuca alternifolia (tea tree) and Eucalyptus globulus essential oils against oralCandida species

Eucalyptus globulus and Melaleuca alternifolia essential oils has been of interest to researchers because they are traditionally used for the treatment of fungal infections and especially candidiasis. The chemical composition of hydrodistilled essential oils were analyzed by gas chromatography-mass spectrometry (GC-MS), and their antifungal activity was tested against 32 Candida strains including 15 species. The antioxidant activities (DPPH, reducing power, and superoxide anion radical-scavenging activity) were also investigated. Tea tree essential oil was particularly rich on terpinen-4-ol (40.44%), gamma terpinene (19.54%) and 1,8-cineole (95.61%) and alpha-pinene (1.5%) for the E. globulus oil. E. globulus oil was more efficient and had the best antifungal effect on oral Candida albicans and Candida glabratastrains comparing to the results obtained with Amphotericin B. Even at low concentrations, these oils drastically impair the maximum yield and growth rate of both C. albicans and C. glabrata on YPD medium. The Tea Tree essential oil displayed the highest DPPH scavenging ability with the lowest IC50 value (IC50, 12.5 µg/ml), the greater reducing power and bleaching of β-carotene (EC50, 24 µgml-1 and IC50, 42 µgml-1, respectively) as compared to E. globulusoil and BHT. These findings support the interest of E. globulus and M. alternifolia essential oilsas an efficient oral hygiene tool (anti-Candida spp.) and as a source of antioxidant compounds. Key words: Candida, Melaleuca alternifolia, Eucalyptus globulus, gas chromatography-mass spectrometry, antioxidant, antifungal activities.

Bio-screening of a few green seaweeds from India for their cytotoxic and antioxidant potential

It has been evidenced in several epidemiological studies that seaweeds when consumed as diet protect against several chronic oxidative stress-related diseases. Seaweeds, raw, cooked, or dried, are used as food in many cultures, although not very popularly in India. Globally, several studies have indicated that seaweeds are a rich source of phenolic compounds and have antioxidant properties. In the present study, we screened methanolic extracts (MEs) of five species of green seaweeds commonly found in India for their cytotoxic activity by brine shrimp lethality assay and antioxidant properties using various in vitro assays, including 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging, reducing power and metal ion chelating assays. A markedly variable, dose-dependent activity was observed in all the seaweed extracts relative to their total phenolic content. Statistical analysis indicated a significantly strong correlation between the DPPH radical scavenging activity and total phenolic content (R(2) = 0.88, P < 0.05) as well as reducing power and total phenolic content (R(2) = 0.99, P < 0.01) of the dry MEs. Also, a very poor correlation between total phenolic content and metal chelating activity (R(2) = 0.13, P > 0.05) was noted. None of the seaweed extracts were potently cytotoxic. The underlying results endorse seaweeds as a rich, novel source of antioxidant compounds needing systemic exploration.

Extraction of antioxidants from eucalyptus (Eucalyptus globulus) bark

The extraction of phenolic compounds from eucalyptus (Eucalyptus globulus) bark was examined with the aim of analyzing the potential of the extracts as natural antioxidants. Experiments were planned according to a 23 factorial design to analyze the influence of temperature and Na2SO3 and NaOH concentrations in aqueous solutions on extraction yield, extract total phenols content, ferric reducing antioxidant power (FRAP), and number- and weight-average molecular weights. Extract total phenols content and FRAP antioxidant activity in the ranges 0.91–2.58 g gallic acid equivalent (GAE)/100 g oven-dried bark and 4.70–11.96 mmol ascorbic acid equivalent (AAE)/100 g oven-dried bark, respectively, demonstrated the potential of eucalyptus bark as a source of antioxidant compounds. Extraction at the highest temperature (100°C), the lowest Na2SO3 concentration (1.5% on oven-dried bark), and without NaOH provided the highest extract total phenols content and FRAP antioxidant activity. Those eucalyptus bark extracts with lower molecular weight showed higher antioxidant activity. Matrix-assisted laser desorption ionization time-of-flight and reverse-phase high-performance liquid chromatography electrospray ionization time-of-flight mass spectrometry revealed the presence of polygalloyl glucoses, catechin, epicatechin, ellagic acid, quercetin-3-o-rhamnoside, and isorhamnetin in eucalyptus bark aqueous extracts.

COMPARATIVE STUDY ON PHENOLIC COMPOUNDS AND ANTIOXIDANT ACTIVITY OF FEUTRELL'S EARLY AND KINNOW PEEL EXTRACTS

Phenolic compounds and antioxidant activities of 70% ethanol extracts of the peels from two Pakistani citrus mandarin cultivars, namely, Feutrell's Early and Kinnow, were investigated. Results were compared with synthetic antioxidants and also with Chinese Ponkan mandarin peel to see the varietal and geographical effects. The cultivars showed the significant differences in total polyphenols, flavonoids and phenolic acids. Ferulic acid ranging from 1193.84 to 1640.87 µg/g dry weight was the dominant phenolic acid in all cultivars. The antioxidant activity of extracts as determined by β-carotene bleaching assay ranged from 28.40 to 43.78% and was in the following order: Kinnow < Feutrell's Early < Ponkan. A strong positive correlation was observed among the analyzed phenolic compounds and the antioxidant capacities. Results reveal that citrus peels under study might be used as an economical source of natural antioxidants, and both cultivars and geographical factors affect the bioactive composition in citrus mandarin peel. PRACTICAL APPLICATIONS Foods from plant origin usually contain natural antioxidants that can scavenge free radical and may contribute to reduce human diseases. Therefore, many studies have been undertaken to find the new sources of antioxidant compounds. Citrus mandarin (Citrus reticulata Blanco) peels are the source of bioactive compounds with enhanced antioxidant activity. Feutrell's Early and Kinnow peels contain a high amount of polyphenols, flavonoids and phenolic acids, and, therefore, can be the basis for food ingredient designed for functional food applications. The varietal and geographical conditions affect the antioxidant potential of citrus cultivars, and Feutrell's Early seems to be a promising one, for its raw material usage in the food and the pharmaceutical industry as a potential natural antioxidant and a functional ingredient.

HPLC Fingerprint of a Flower Extract of Tilia × viridis and Correlation with Antiproliferative and Antioxidant Activity

Tilia species have been used in Europe and in America to treat anxiety and also for the treatment of colds, influenza, bronchitis, fever and inflammation. Tilia × viridis is a Tilia species distributed widely in Buenos Aires, Argentina. The flavonoids present in Tilia species have antioxidant properties, acting as reactive oxygen species (ROS) scavengers, principally on hydrogen peroxide (H(2)O(2)) and the superoxide anion (O(2)(·-)), which are involved in many diseases, including cancer. The aim of this study was to determine the phytochemical pattern of the ethanol extract of Tilia × viridis, principally the flavonoid content, and to evaluate the antiproliferative effects on both normal and tumoral cells, and the antioxidant activity in relation to H(2)O(2) modulation. The extract was found to present a selective antiproliferative activity on a lymphoma cell line and this was related to free radical scavenging activity. In addition, one of its main compounds, rutin, showed antioxidant effects related to peroxidase activity. T. × viridis may therefore be a source of antioxidant compounds that contribute to a selective antiproliferative action on tumoral cells, acting by modulation of H(2)O(2) levels.

Phenolic compounds content and antioxidant activity in pomace from selected red grapes (Vitis vinifera L. and Vitis labrusca L.) widely produced in Brazil

The phenolic compounds content and antioxidant activity of pomace from the vinification of grape varieties widely produced in Brazil (Cabernet Sauvignon, Merlot, Bordeaux and Isabel) were investigated with a view to their exploitation as a potential source of natural antioxidants. Cabernet Sauvignon grape pomace was found to have the highest content of total phenolic compounds (74.75mg gallic acid equivalent (GAE)/g), the highest antioxidant activity (determined using the 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonate) (ABTS) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging methods; 485.42 and 505.52μMol Trolox equivalent antioxidant capacity (TEAC)/g, respectively), and the highest reducing power (determined using the FRAP method; 249.46μMol TEAC/g). The Bordeaux variety showed the highest oxidation inhibition power (41.13%), determined using the β-carotene/linoleic acid method and the highest content of total anthocyanins (HPLC; 29.17mg/g). Catechin was the most abundant non-anthocyanic compound identified in the grape pomace (150.16mg/100g) for all varieties. In this study, pomaces of the red wine vinification of Cabernet Sauvignon and Bordeaux varieties showed the highest potential as a source of antioxidant compounds and natural colourants, respectively.

Supercritical fluid extraction with a modifier of antioxidant compounds from jabuticaba (Myrciaria cauliflora) byproducts: economic viability

Jabuticaba (Myrciaria cauliflora) is a grape-like fruit that is found extensively throughout Brazil. In spite of the very few studies done on its chemical constituents, some authors have reported the potential use of jabuticaba as a source of antioxidant compounds, which are believed to play an important role in the prevention of many oxidative and inflammatory diseases. Local populations enjoy jabuticaba as a favorite fruit, but the majority of these crops are wasted during harvesting and processing. Thus, the application of innovative technologies such as supercritical fluid extraction (SFE) for processing by-products is important to obtain high quality yields, which increases the value of the product. In addition, processing by-products currently represents an increasing niche market, which is mainly due to their ecological, economic and social implications. In order to evaluate their industrial applicability, it is essential to perform a critical analysis of the chemical composition and economic viability of the extracts obtained. The objective of this study is to evaluate the feasibility of antioxidant recovery by SFE with a co-solvent using varying conditions of pressure and temperature. SFE was carried out under two temperatures (323 and 333K) and three pressures (10, 20 and 30MPa) using ethanol as a modifier at 20% v/v, for a total of six different extraction conditions. The assays were performed in triplicate. The extracts were evaluated for their global yield (X0) and antioxidant capacity by radical scavenging activity using the DPPH method.

In vitro cultures of Salvia officinalis L. as a source of antioxidant compounds

The concentrations of carnosic acid, carnosol and rosmarinic acid in different materials from differentiated (multiple shoot cultures and regenerated plants) and undifferentiated (callus and cell suspension) in vitro cultures of &lt;em&gt;Salvia officinalis&lt;/em&gt; were determined by HPLC. The results suggested that diterpenoid (carnosic acid and carnosol) production is closely related to shoot differentiation. The highest diterpenoid yield (11.4 mg g&lt;sup&gt;-1&lt;/sup&gt; for carnosic acid and 1.1 mg g&lt;sup&gt;-1&lt;/sup&gt; for carnosol) was achieved in shoots of 10-week-old micropropagated plants. The levels were comparable to those found in shoots of naturally growing plants. Undifferentiated callus and cell suspension cultures produced only very low amounts of carnosol (ca. 0.05 mg g&lt;sup&gt;-1&lt;/sup&gt; of dry weight). In contrast, content of rosmarinic acid in callus and suspension cultures as well as shoots growing in vitro and in vivo was similar and ranged between 11.2 and 18.6 mg g&lt;sup&gt;-1&lt;/sup&gt; of dry weight.

Determination and Evaluation of Antioxidative Activity in Red Dragon Fruit (&lt;i&gt;Hylocereus undatus&lt;/i&gt;) and Green Kiwi Fruit (&lt;i&gt;Actinidia deliciosa&lt;/i&gt;)

Problem statement: Dragon fruit or pitahaya (Hylocereus undatus), is believed to be a healthy source of vitamins, fiber and antioxidants, especially the red-fleshed varieties which contain lycopene. Approach:Compared to green kiwi fruit (Actinidia deliciosa), which already known contain high antioxidant activity. Results:The antioxidant capacity of Hylocereus undatus (H. undatus) and Actinidia deliciosa (A. deliciosa) in three different solvent extraction; ethanol, methanol and aqueous, was estimated by DPPH free radical scavenging assay. The inhibition of free radical by A. deliciosa is almost 90% compared with H. undatus which only 60-10% in different solvents. Additionally, their total phenolic contents were analyzed by folin-ciocalteau method. The result showed that A. deliciosa (533.70 mg L-1 in ethanol, 460.87 mg L-1 in methanol and 420.652 mg L-1 in distilled water) seemed to be better sources of antioxidant compounds then H. undatus (179.35 mg L-1 in ethanol, 160.87 mg L-1 in methanol and 157.61 in distilled water). Conclusion: When compared between the three different solvent, extract in ethanol shown the most highly antioxidant content followed by methanol and water. The experiment showed the potential of dragon fruit and kiwi extracts high rich in antioxidant which can scavenge free radical in human body. Further study on isolation of individual antioxidant in both extracts can be providing for commercialize the extracts in jus form.

Influence on Olive Leaves (&lt;i&gt;Olea Europaea&lt;/i&gt;, var. Serrana) Antioxidant Extraction Kinetics of Ultrasound Assisted Drying

The olive crop has a great importance in the economy of Spain. Every year during the pruning of the olive trees a significant quantity of leaves are cut and discarded. It is known that these leaves constitute a source of antioxidant compounds and its processing would provide an added value to this raw material. Antioxidant compounds may be damaged when drying, the previous process to extraction. Thus, the goal of this work was to study the influence of the high intensity ultrasound applied during the drying of olive leaves on the kinetic of extraction of antioxidants compounds. From the parameters identified from Naik model, it can be concluded that the application of high intensity ultrasound during drying reduced the antioxidant activity of extracts at the equilibrium but increased the initial extraction kinetic compared to conventional hot air drying. This last aspect could have high interest to the antioxidant extraction from an industrial scale point of view.

Optimisation of Polyphenols Extraction from Chestnut Shell by Response Surface Methodology

The extraction of polyphenols from a waste product from the food industry, the shell of the chestnut fruit, was examined with the aim of analyzing the potential of the extracts for the formulation of wood adhesives, for leather tanning and as natural antioxidants. Experiments were planned according to a 23 factorial design to analyze the influence of temperature and Na2SO3 and NaOH concentrations on extraction yield and on different extract properties: Stiasny number, total phenols, tannins and non-tannins contents, tannin/soluble solids ratio, proanthocyanidins content, antioxidant activity, average molecular weights, surface tension and power law rheological parameters of extract aqueous solutions. Extraction yields in the range 26.1–56.4% together with extract Stiasny numbers higher than 84 and total phenols contents and FRAP antioxidant activities in the range 10.86–33.33 g GAE/100 g shell and 92.05–166.32 mmol AAE/100 g shell, respectively, demonstrated the potential of chestnut shell extracts in the formulation of adhesives and as sources of antioxidant compounds. Additionally, the surfactant character and pseudoplastic behaviour of chestnut shell extracts solutions could improve wood wettability when used in adhesive formulation. Under a range of operating conditions, extracts with tannin content higher than 10% and tannin/soluble solids ratio higher than 0.6 were obtained that could be used as tanning agents. The experimental design performed demonstrated the capacity of chestnut shell extracts for the applications proposed and allowed selecting the optimal extraction conditions for obtaining not only high quality extracts but also high extraction yields.

Evaluation of potential applications for chestnut ( Castanea sativa) shell and eucalyptus ( Eucalyptus globulus) bark extracts

The potential of chestnut shell and eucalyptus bark extracts as phenol substitutes in the formulation of adhesives, as chrome substitutes in leather tanning and as a source of antioxidants compounds has been studied. The influence of extraction conditions, type and concentration of alkaline compounds (NaOH, Na 2SO 3 and Na 2CO 3) and temperature, on extraction yield and on extract characteristics: Stiasny number, tannin content, total phenols content, FRAP (ferric reducing/antioxidant power) antioxidant capacity and molecular weight distribution was analysed. Chestnut shell extracts had much better properties than eucalyptus bark extracts and significantly higher extraction yields were obtained. The increase of temperature from 70 to 90 °C not only increased the extraction yield but also improved the quality of the extracts. For both materials, the 2.5% Na 2SO 3–90 °C extract, together with the 2.5% NaOH–2.5% Na 2SO 3–90 °C extract for chestnut shell, showed high extraction yields and the best properties for all the applications proposed.

Antioxidant activity and total phenolic content of Agaricus brasiliensis ( Agaricus blazei Murril) in two stages of maturity

The antioxidant capability and total phenolic contents of methanolic extracts of Agaricus brasiliensis in two stages of maturity, young (YB) and mature (MB), were evaluated in this work. Four complementary assays, reducing power, radical scavenging capacity, inhibition of lipid peroxidation and chelating ability for ferrous ions were used to screen the antioxidant properties of extracts. Minor differences in the composition of phenolic compounds were detected, but the extracts showed similar antioxidant activities, except for the chelating ability for ferrous ions, higher in MB than in YB. Our results support the use of both young and mature fruiting bodies of Agaricus blazei as sources of antioxidant compounds.

In vitro radical scavenging activity of two Columbian Magnoliaceae

The recent interest in the conservation of the tropical forest is due, at least in part, to the potential economic and health benefits that can be exploited from several plants. This report shows the in vitro antioxidant activity of some fractions isolated from leaves of two Columbian Magnoliaceae, Talauma hernandezii G. Lozano-C and Dugandiodendron yarumalense Lozano. The activity was determined using the radical monocation 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS.+) and the stable free radical 2-2-diphenyl-1-picrylhydrazyl (DPPH.), as part of general biological screening of these plants. The antioxidant capacity obtained from fractions was similar to those of alpha-tocopherol, tert-butylated hydroxyanisole (BHA), and ascorbic acid. The most active scavenger extract was the fraction 7 (TAA = 48.6 mmol Trolox/kg extract and IC50 < or = 0.01 kg extract/mmol DPPH); and the least active was the fraction 1 (TAA = 11.23 mmol Trolox/kg extract and IC50 = 0.21 kg extract/mmol DPPH) all of them isolated from D. yarumalense. These results suggest that these plants can be attractive as source of antioxidant compounds with the ability to reduce radicals like ATBS and DPPH.

Antioxidant activity of leaf extracts from Bauhinia monandra

Bauhinia monandra Kurz. is used in Brazil for the treatment of diabetes. Since this activity may be correlated with the presence of antioxidant compounds, leaf extracts of B. monandra were evaluated for their radical scavenging capacity (RSC). An ethanolic extract was taken up in aqueous methanol and partitioned with hexane, chloroform, ethyl acetate to yield three organic extracts together with remaining aqueous extract. The RSC was determined spectrophotometrically using 1,1-diphenylpicrylhydrazyl free radical (DPPH). The chloroform and ethyl acetate extracts were the most appropriate as sources of antioxidant compounds as shown by their inhibition concentration (IC 50) and inhibition percentage (IP) values. The antioxidant activity of such extracts was attributed to the presence of three compounds of different polarities (flavonoids and steroids). The chloroform and ethyl acetate extracts exhibited an IC 50 of approximately 2 mg/g DPPH and IP values in the range of 60–65%. The results indicate that the extracts of B. monandra have a very potent antioxidant activity, compared with the pure catechins used as positive controls and with other plant extracts.