New Source Of Natural Antioxidants Research Articles

Atividade antioxidante da polpa, casca e sementes do noni (Morinda citrifolia Linn)

Na busca pela identificação de novas fontes de antioxidantes naturais e de esclarecer lacunas acerca das reais propriedades benéficas atribuídas ao Noni (Morinda citrifolia Linn), este trabalho teve como objetivo realizar a caracterização química e avaliar a atividade antioxidante da polpa, casca e sementes do noni. Foram determinadas a composição centesimal (umidade, cinzas, proteínas, carboidratos e lipídios); os compostos bioativos (fenólicos totais, carotenoides totais e vitamina C) e a atividade in vitro em extratos aquoso, etanólico e acetônico. Os resultados demonstraram que o Noni possui quantidades significativas de carboidratos (27,21%; 9,70% e 8,37%) e de proteínas (2,64%; 2,23%; e 2,24%) nas sementes, casca e polpa, respectivamente. A polpa apresentou maior teor de vitamina C (23,1 mg/100g) e de carotenoides totais (3,90 mg/100g). No extrato acetônico da polpa, foram quantificados 109,81 mg/100g de fenólicos totais, seguidos pelos extratos acetônicos da casca (76,01 mg/100g), das sementes (28,75 mg/100g) e do extrato etanólico da polpa (20,33 mg/100g). Todos os extratos avaliados apresentaram atividade antioxidante in vitro; os extratos acetônico e etanólico da casca e das sementes do Noni apresentaram maior atividade pelo método β-caroteno/ ácido linoleico, enquanto o extrato etanólico da polpa teve maior atividade antioxidante pelo ensaio DPPH e ABTS, e o extrato acetônico da polpa, pelo método ABTS. O noni é um fruto com significativo teor de compostos fenólicos totais que apresentam atividade antioxidante in vitro.

Production and characterization of an extracellular polysaccharide from Streptomyces violaceus MM72

The isolation, optimization, purification and characterization of an extracellular polysaccharide (EPS) from a marine actinobacterium, Streptomyces violaceus MM72 were investigated. Medium composition and culture conditions for the EPS production by S. violaceus MM72 were optimized using two statistical methods: Plackett–Burman design applied to find the key ingredients and conditions for the best yield of EPS production and central composite design used to optimize the concentration of the three significant variables: glucose, tryptone and NaCl. The preferable culture conditions for EPS production were pH 7.0, temperature 35°C and NaCl concentration 2.0% for 120h with fructose and yeast extract as best carbon and nitrogen sources, respectively. The results showed that S. violaceus MM72 produced a kind of EPS having molecular weight of 8.96×105Da. In addition, the EPS showed strong DPPH radical-scavenging activity, superoxide scavenging and metal chelating activities while moderate inhibition of lipid peroxidation and reducing activities determined in this study. These results showed the great potential of EPS produced by S. violaceus MM72 could be used in industry in place of synthetic compounds. The EPS from S. violaceus MM72 may be a new source of natural antioxidants with potential value for health, food and therapeutics.

Assessment of the antioxidant potential and fatty acid composition of four Centaurea L. taxa from Turkey

This paper focused on the assessment of antioxidant property and fatty acid composition of four Centaurea species. The antioxidant activity of its methanol extract was evaluated by several in vitro experiments including phosphomolybedum assay, DPPH assay, β-carotene/linoleic acid, ferric and cupric reducing power. Total phenolic and flavonoid contents were also evaluated. The methanol extract of Centaurea pulcherrima var. pulcherrima showed the superior free radical scavenging activity, linoleic acid inhibition capacity, reducing power and also had the highest total phenolic content. A significant relationship between antioxidant capacity and total phenolic components was found. The oils of Centaurea taxa were also analysed for fatty acid concentration by gas chromatography. The principal fatty acids in the species were palmitic acid (23.38–30.49%) and linoleic acid (20.19–29.93%). These findings suggest that the Centaurea species could be used as a potential source of new natural antioxidants and unsaturated fatty acids in food industry, cosmetics and pharmaceutical preparations.

Comparative studies on the antioxidant potential of vanillin-producing Saccharomyces boulardii extracts

Free radical-scavenging antioxidants have the potential as protective agents against various degenerative diseases caused by oxidative damage. Microorganisms are shown to be a promising new source of natural antioxidants. In the present study, supernatant (crude extract) and different solvent extracts (ethyl acetate, n-butanol, dichloromethane) of Saccharomyces boulardii’s growth were evaluated for the antioxidant activity using free radical scavenging (1,1-Diphenyl-2-picryl hydrazyl; DPPH) assay, superoxide radical scavenging (nitroblue tetrazolium; NBT) assay, and by estimating total phenolic and flavonoid contents (TPC and TFC). Antioxidative potential of S.boulardii extract was also tested in biological system, i.e. A549 lung cancer cell line using dichlorofluoroscein diacetate (DCF-DA) assay. Organic extracts were further explored by HPLC and mass spectrometry techniques to identify active principles responsible for antioxidant activity. Comparative studies on antiradical ability (DPPH, NBT) revealed that crude extract has the highest activity than its other solvent counterparts as evident by its lower IC50 values and higher TPC and TFC. In vitro studies also showed that S.boulardii extracts effectively quench intracellular reactive oxygen species. Vanillin was identified as one of the contributing antioxidant. It was found that S.boulardii extract is an efficient scavenger of free radicals and can be exploited as a potential new source of natural antioxidants.

Rapid micropropagation system in vitro and antioxidant activity of Scabiosa tschiliensis Grunning

A rapid micropropagation system for Scabiosa tschiliensis Grunning, an ethnic medicinal plant, has been developed. Calluses were induced from leaf and petiole explants on Murashige and Skoog (MS) medium supplemented with 2.0 mg l−1 thidiazuron and 0.5 mg l−1 2,4-dicholorophenoxyacetic acid. In this medium, callus induction rate was about 94.05 %. Adventitious shoots developed from leaf (86.30 %) and petiole (83.33 %) calluses when cultured on MS medium containing 4.0 or 2.0 mg l−1 N6-benzyladenine (BA), respectively. Up to 73.85 % of the regenerated shoots formed complete plantlets on MS medium supplemented with 2.0 mg l−1 indole-3-butyric acid, with an average of 3.25 roots per shoot. Quantitative analysis of flavonoids showed that the phytochemical profiles of calluses and regenerated plants were similar to that of wild-type plants. The 2, 2-diphenyl-1-picrylhydrazyl assay revealed that the flavonoid extracts of calluses, adventitious shoots and wild-type plants had stronger antioxidant activities, the inhibitory concentrations being 23.944, 31.329 and 26.502 μg ml−1, respectively, where 50 % of DPPH was scavenged (IC50). Results showed that this perennial herb could be used as a potential source of new natural antioxidants.

Guttation droplets of the edible mushroom Suillus bovinus as a new source of natural antioxidants

Although guttation is a well-known feature of several filamentous fungi, their potential as natural antioxidant sources is unknown. This study investigates the antioxidant capacity of the exudate produced by the wild edible mushroom Suillus bovinus and the effect of the temperature and of light/darkness exposure on antioxidants synthesis. The fungus was grown on solid media at 18°C or 25°C, under light/darkness conditions. The antioxidant activity of the exudate was evaluated by using 2,2-diphenyl-1-picrylhydrazyl radical scavenging capacity (DPPH) and reducing power assays. The fungal exudate proved to have antioxidant activity, showing values of reducing power ranging from 0.450 to 0.528, and of scavenging effects on DPPH radicals from 75.68 to 82.38%. Colonies grown under continuous light at 18°C had the lowest growth rate and exudate volume, but these environmental conditions proved to be the most appropriate to increase antioxidant activity of the droplets. These results indicated that the droplets of S. bovinus are a promising source of natural antioxidants and provide useful information on how to manipulate the production of such compounds.

TLC Screening for Antioxidant Activity of Extracts from Fifteen Bamboo Species and Identification of Antioxidant Flavone Glycosides from Leaves of Bambusa. textilis McClure

Interest in the antioxidant activity of bamboo leaves is growing. To discover new sources of natural antioxidants, a TLC bioautography method combined with a new image processing method was developed to evaluate the antioxidant activity of leaf extracts from 15 different species of bamboo. The results showed that the methanolic extract of Bambusa. textilis McClure possessed the highest antioxidant activity among the selected bamboo species. To rapidly identify the antioxidant compounds, the crude extract of B. textilis McClure was analysed by HPLC-UV, and HPLC-micro-fractionation of the extract was carried out. Based on TLC bioautography-guided fractionation, three antioxidant fractions were isolated from B. textilis McClure by preparative chromatography. These three antioxidant compounds were identified as isoorientin 4''-O-β-D-xylopyranoside (1), isoorientin 2''-O-α-L-rhamnoside (2) and isoorientin (3) according to their UV, MS, and NMR data. The proposed TLC screening method could therefore be an easy way to evaluate the antioxidant activity of bamboo leaves, and the results achieved should prove very helpful for promoting their utilization, as B. textilis McClure can be considered a promising plant source of natural antioxidants.

Variability of phenolic composition and biological activities of two Tunisian halophyte species from contrasted regions

The present study consists in evaluating the inter- and intraspecific variability of phenolic contents and biological capacities of Limoniastrum monopetalum L. and L. guyonianum Boiss. extracts. Ultimately, they were subjected to HPLC for phenolic identification. Results showed a great variation of phenolic content as function of species and localities. In fact, L. guyonianum extracts (El Akarit) contained the highest polyphenol (57 mg GAE g−1 DW), flavonoid (9.47 mg CE g−1 DW) and condensed tannin contents (106.58 mg CE g−1 DW). These amounts were accompanied by the greatest total antioxidant activity (128.53 mg GAE g−1 DW), antiradical capacity (IC50 = 4.68 μg/ml) and reducing power (EC50 = 120 μg/ml). In addition, L. monopetalum and L. guyonianum extracts exhibited an important and variable antibacterial activity with a diameter of inhibition zone ranging from 6.00 to 14.83 mm. Furthermore, these extracts displayed considerable antifungal activity. L. monopetalum extracts (Enfidha) showed the strongest activity against Candida glabrata and C. krusei with a diameter exceeding 12 mm. The phytochemical investigation of these extracts confirmed the variability of phenolic composition, since the major phenolic compound varied as a function of species and locality. These findings suggest that these two halophytes may be a new source of natural antioxidants that are increasingly important for human consumption, as well as for agro-food, cosmetic and pharmaceutical industries.

Optimization and characterization of a polysaccharide produced by Pseudomonas fluorescens WR-1 and its antioxidant activity

The extracellular polysaccharide produced by a newly isolated strain Pseudomonas fluorescens WR-1 was purified and characterized and its production was optimized using response surface methodology. The results showed that the strain WR-1 produced one kind of EPS that was composed of arabinose, glucose and uronic acid. The molecular weight of the EPS was determined to be 6.78×106Da. The preferable culture conditions for EPS production were pH 7.0, temperature 28°C for 72h with peptone and maltose as best N and C sources, respectively. The model predicted that the maximum EPS production (39.6gL−1) was appeared with maltose 48.65gL−1, Mn2+ 1118μM and Zn2+ 901μM. The EPS also showed good H2O2 scavenging activity while moderate free radical scavenging activity and reductive ability were determined. The EPS from WR-1 may be a new source of natural antioxidants with potential value for health, food and industry.

Antioxidant ActivitiesIn Vitroof Ethanol Extract and Fractions from Mushroom,Lenzites Betulina

The antioxidant potential of different fractions of Lenzites betulina was investigated. Fraction 2 showed the highest antioxidant activity in the 2, 2-diphenyl-1-picrylhydrazyl (DPPH) and hydroxyl (OH) radical-scavenging assays. Three natural p-terphenyls were identified in this fraction. The structure of a new natural compound was established as 2-phenyl-[1H-2-benzopyran][4,3-e][p]benzoquinone in addition to two other compounds, 2,5-diphenyl-3,6-dimethoxy-p-benzoquinone and 2-phenyl-3-methoxy-[1H-2-benzopyran][4,3-e][p]benzoquinone that have been previously reported in L. betulina. The antioxidant activities of these p-terphenyls were evaluated by DPPH and OH radical-scavenging assays. 2-phenyl-3-methoxy-[1H-2-benzopyran][4,3-e][p]benzoquinone was the most active in the OH radical-scavenging test (IC 50 = 37.69 μg/mL) and showed little inhibition in the DPPH assay. The chemical components of L. betulina therefore have some antioxidant capacities, and this species could be used as a potential source of new natural antioxidants. Practical Applications Lenzites betulina has been used as a kind of medicinal fungus in China. In order to find its potential application, the antioxidant potential of L. betulina was investigated. It was found that the total ethanol extracts and the fraction 2 of L. betulina showed strong antioxidative capacity in the 2, 2-diphenyl-1-picrylhydrazyl and hydroxyl (OH) radical-scavenging assays. The OH radical-scavenging activity of the fraction 2 (IC 50 = 19.42 ± 0.4 μg/mL) was similar to that of ascorbic acid (IC 50 = 20.55 ± 0.2 μg/mL). Meanwhile, three natural p-terphenyl (a new natural compound and two known compounds) were identified in this fraction. Compound 2 showed the most activity in the OH radical-scavenging test (IC 50 = 37.69 μg/mL), so this species could be used as a potential source of new natural antioxidants.

ANTIOXIDANT POTENTIAL AND OXIDATIVE DNA DAMAGE PREVENTIVE ACTIVITY OFCHRYSANTHEMUM INDICUMEXTRACTS

ABSTRACT The objective of this study was to characterize the antioxidant properties of the extracts from Chrysanthemum indicum flower (CIF). The water and ethanol extracts were prepared from CIF and its antioxidant activity was investigated in vitro by different methods including 1,1-diphenyl-2-picrylhydrazyl, 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt, hydroxyl and superoxide radicals and nitrite scavenging, reducing (Fe3+ to Fe2+) power, linoleic acid oxidation inhibition as well as free radical-induced DNA damage prevention activity. The cytotoxic effect of the ethanol extract was determined on chang normal liver cell. The ethanol-based extract prevented free radical-induced DNA damage and did not show any cytotoxicity. The antioxidant activity was highly correlated with the observed phenolic and flavonoid contents. The present study suggests that the extracts of CIF could be considered as a potent source of natural antioxidants. PRACTICAL APPLICATIONS Chrysanthemum indicum Linné has been used as a traditional medicine for various immune-related diseases as well as in mixed spices and alcoholic beverages in Korea, China and Japan. The tea prepared from chrysanthemum flower could prevent sore throat and promote the reduction of fever. Recently, Chrysanthemum indicum flower (CIF) extracts has been reported to have therapeutic potential in a variety of immune-related cutaneous diseases and lowering blood pressure activity. In this context, we studied antioxidant activities and DNA damage preventive activity of CIF. The results suggest that the extract may have potential as a new source of natural antioxidant.

Ontogenetic Variation of Total Phenolics and Antioxidant Activity in Roots, Leaves and Flowers of Astragalus compactus Lam. (Fabaceae).

The potential health risks and toxicity of synthetic antioxidants resulted in an upsurge of interest in phytochemicals as new sources of natural antioxidants. Phenolics of Astragalus L. (Fabaceae) possess antioxidant properties and have been shown to have a protective effect against several degenerative diseases. The objective of this study was to determine total phenolics and antioxidant activity of methanolic extracts from different parts of A. compactus Lam. at different phenological phases and to investigate the correlations between antioxidation and the contents of the total phenolics. Total phenolic content (TPC) was determined using the Folin-Ciocalteau reagent and the antioxidant capacity was evaluated with the 1,1-diphenyl-2-picrylhydrazyl (DPPH) test. Generally, the TPC in leaves was higher than that of the roots and flowers. TPC in leaves, roots and flowers of the species varied from 5.01-8.25, 4.29-7.89 and 4.19 μg GAE/mg DW, respectively. In addition, roots and leaves at fructification stage possessed higher TPC than vegetative and flowering stages. Therefore, the leaf extracts at fructification phase showed the highest TPC that accompanied with best antioxidant activity. In the root extracts, fructification stage was also characterized by the highest antioxidant activity. A positive relationship between antioxidant activity and TPC showed that phenolics were the dominant antioxidant components in the species. The results obtained suggest that A. compactus methanolic extracts may serve as potential sources of natural phenolic antioxidants and that the fructification phase could be considered as the best stage for the harvesting of this plant.

Antioxidant potential of microalgae in relation to their phenolic and carotenoid content

In the past decades, food scientists have been searching for natural alternatives to replace synthetic antioxidants. In order to evaluate the potential of microalgae as new source of safe antioxidants, 32 microalgal biomass samples were screened for their antioxidant capacity using three antioxidant assays, and both total phenolic content and carotenoid content were measured. Microalgae were extracted using a one-step extraction with ethanol/water, and alternatively, a three-step fractionation procedure using successively hexane, ethyl acetate, and water. Antioxidant activity of the extracts varied strongly between species and further depended on growth conditions and the solvent used for extraction. It was found that industrially cultivated samples of Tetraselmis suecica, Botryococcus braunii, Neochloris oleoabundans, Isochrysis sp., Chlorella vulgaris, and Phaeodactylum tricornutum possessed the highest antioxidant capacities in this study and thus could be a potential new source of natural antioxidants. The results from the different types of extracts clearly indicated that next to the well-studied carotenoids, phenolic compounds also contribute significantly to the antioxidant capacity of microalgae.

ANTIOXIDANT AND ANTIBACTERIAL ACTIVITIES OF VARIOUS EXTRACTS OFBORAGO OFFICINALISFLOWERS

ABSTRACT Antioxidant and antibacterial activities of various extract of Borage (Borago officinalis) flowers were evaluated. The antioxidant activity of the extracts was assessed using 2,2-diphenyl-1-picrylhydrazyl (DPPH), β-carotene/linoleic acid and reducing power assays. In DPPH assay, the order of free radical scavenging activity of the extracts was: methanol extract (ME) > acetone extract (AE) > water extract (WE). In β-carotene/linoleic acid assay, the inhibition capacity (%) of WE (95.62%) was in the highest level. When reducing power assay was used, a similar activity pattern was observed as given in the DPPH assay. The antibacterial activity of the extracts was tested by disk agar diffusion against four bacteria. The AE and WE of Borage flowers were effective against Bacillus subtilis and Listeria monocytogenes, respectively. In conclusion, the WE of Borage flower showed potent antioxidant activity. PRACTICAL APPLICATIONS In recent years, many researches have been carried out to find new sources of natural antioxidants. Natural antioxidants, derived from plants, can be used to preserve raw and processed foods. B. officinalis flowers are used as herbal tea and medicine in Iran. However, its antioxidant activity is still unknown. In this study, the WE of Borage exhibited potent antioxidant activity. Therefore, this extract has the potential to be used in food systems.

Antioxidant and antimicrobial activities of Saraca thaipingensis Cantley ex Prain

ObjectiveTo investigate antioxidant and antimicrobial activities of Saraca thaipingensis Cantley ex Prain; and isolation of its flower extracts. MethodsThe plant species (flowers, leaves, and twigs) were extracted by hexane, dichloromethane, ethyl acetate and methanol; and tested for antioxidant activity (DPPH assay) and antimicrobial activity (agar dilution method) against twenty-seven strains of microorganisms; gram positive and gram negative bacteria, and diploid fungus. Bioactive constituents were isolated by column chromatography. ResultsThe plant extracts has been firstly reported to display strong antioxidant activity and antimicrobial activity selective against gram positive bacteria (Corynebacterium diphtheriae NCTC 10356 and Streptococcus pyogenes) with MIC of 256 μg/mL. Stigmasterol and a mixture of triterpenoids and phenolic compounds were isolated from the flower extracts. ConclusionsThe study revealed that the S. thaipingensis is a new source of natural antioxidants and antimicrobials with potential for medicinal uses.

ANTIOXIDANT ACTIVITY OF MUME FRUCTUS EXTRACT

We have evaluated the antioxidant and radical scavenging activity of the water extract of Mume Fructus by applying various in vitro assays. We have determined total phenolic and flavonoid contents, 1,1‐diphenyl‐2‐picryl‐hydrazyl (DPPH), 2,2′‐azino‐bis(3‐ethylbenzthiazoline‐6‐sulfonic acid) (ABTS), hydroxyl radical (OH•), superoxide radical (O2 ‐•) and nitrite scavenging activities, inhibition of linoleic acid oxidation and reducing power activity. The extract exhibited high scavenging activities on DPPH, ABTS, hydroxyl and superoxide radicals with the IC50 of 0.40, 0.36, 1.75 and 1.60 mg/mL, respectively. The extract also showed nitrite scavenging and reducing power activity in a dose‐dependent manner. It inhibited 69.42% of linoleic acid oxidation at the concentration of 0.4 mg/mL. Owing to have high antioxidant activity, the water extract of Mume Fructus may serve as a new dietary supplement. PRACTICAL APPLICATIONS: Mume Fructus has been used as a medicine in China, Korea and Japan. It has been reported that the water extract of Mume Fructus is able to inhibit pro‐inflammatory mediators in lipopolysaccharide‐stimulated macrophages. The fruit has been used for stomachic, alexipharmic expectorant and eye pain and skin disease since before. People also used fruits as folk medicine for fever, cough and intestinal disorder, etc. Dried fruits have been used for thirst, refrigerant, laxative. In addition, previous reporters showed the inhibitory activities of fruit juice against Helicobacter pylori motility, human influenza disease as well as proliferation of cancer cells. In this context, we studied antioxidant and free radical‐scavenging activities of Mume Fructus in vitro. The results of this study suggest that it may have potential as new source of natural antioxidant and dietary supplement.

Antioxidant and anti food-borne bacterial activities of extracts from leaf and different fruit parts of Myristica fragrans Houtt

The main products of Myristica fragrans are the dried seed (nutmeg) and aril (mace), which are used as spices or condiments to flavor foods. In this study, its leaf and different parts of fruit (pericarp, aril, seed-kernel and shell) were compared for their total phenolic content, antioxidant and anti food-borne bacterial capacities. The 80% methanol extracts of aril, seed-kernel and shell shared the highest total phenolic content with shell extract acted as the greatest primary antioxidant, by having the highest ferric reducing antioxidant power (FRAP) activity (EC50 9.7±0.1μg/mL), β-carotene-bleaching activity (EC50 21.5±2.7μg/mL) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging activity (EC50 160.9±13.9μg/mL), whereas the pericarp extract exhibited highest secondary antioxidant activity as a metal chelator (EC50 75.6±14.4μg/mL). Only the aril and seed-kernel extracts were found to inhibit the food-borne bacteria with the lowest minimum inhibition concentration of 50μg/mL, against Staphylococcus aureus (ATCC12600) and Bacillus cereus (ATCC10876). Our findings suggest the possibility of using the aril and seed-kernel extracts as natural food preservative and other parts as a new source of natural antioxidant for food and pharmaceutical industries.

Antioxidant Activity of Some Carduus Species Growing in Bulgaria

Background: Species of genus Carduus are traditionally used in Bulgarian folk medicine as diuretic, cardiotonic and antihemorroidal remedies. C. candicans ssp. globifer and C. kerneri ssp. austro-orientalis are Balkan endemic, whereas C. acanthoides, C. nutans, C. thoermeri C. are invasive alien weeds in the Americas, Australia and New Zealand, and causes major economic losses. The aim of the present study was to screen some Carduus spesies growing in Bulgaria for radical scavenging and inhibitition of lipid peroxidation in order to discover new natural sources of antioxidants for further investigation. Methods: Antioxidant activity of Carduus species were investigated using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2´-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) di-ammonium salt (ABTS) free radicals; ferric reducing antioxidant power (FRAP) assay and inhibition of lipid peroxidation in linoleic acid system by the ferric thiocyanate method (FTC). Butylated hydroxytoluene (BHT) and ascorbic acid were used as positive controls. In addition, the quantification of total water soluble polyphenols and flavanoids were determinate by Folin-Chiocalteu reagent and AlCl3, respectively. Results: The highest concentrations of total water soluble polyphenols and flavonoids were found in C. thoermeri (2.06 ± 0.03 g /100 g dw and 3.31 ± 0.12 g /100 g dw, respectively), followed by C. nutans (1.88 ± 0.01 g/100 g dw; 2.60 ± 0.09 g /100 g dw, respectively) and C. candicans ssp. globifer (1.85 ± 0.04 g/100 g dw). Conclusions: All tested extracts demonstrate significant antioxidant activity moreover C. thoermeri, C. nutans and C. candicans ssp. globifer were found to be the most potent and can be a good new source of natural antioxidants.

Screening for in vitro antioxidant properties and fatty acid profiles of five Centaurea L. species from Turkey flora

Centaurea species are used for the treatment of various ailments in the popular medicine in some countries. This study was designed to examine antioxidant potentials and fatty acid profiles of five Centaurea species from Turkey flora. Antioxidant properties of methanolic extracts from these species were evaluated by six different methods: phosphomolybdenum assay, free radical scavenging assay, β-carotene/linoleic acid test system, metal chelating activity, ferric and cupric reducing power. Total phenolic and flavonoid concentrations of each extract were also determined using the Folin–Ciocalteu reagent and aluminum chloride. The results of these assay showed a significant antioxidant capacity in all researched extracts. Centaurea cheirolopha extract, with the highest amount of total phenolic and flavonoids, showed the highest antioxidant activities in all assay, except for metal chelating. Fatty acid profiles of these species were examined by GC–FID and 30 fatty acids were identified. Palmitic, linoleic, oleic, and linolenic acid were detected as the main components. The results of the study indicated that the Centaurea species can be considered as a source of new natural antioxidants and unsaturated fatty acids for food, cosmetic and pharmaceutical industries.

ANTIOXIDANT ACTIVITY AND PHENOLIC CONTENT OF FLOUR AND PROTEIN CONCENTRATE OF AMARANTHUS CRUENTUS SEEDS

The aim of this work was to investigate bioactive compounds and antioxidant activity in flour (FAc) and protein concentrate (PCAc) from Amaranthus cruentus seeds (Ac), and to study their effect on the liver histoarchitecture of Wistar rats. Total phenols (mg gallic acid eq/100 g dry weight) content was 73.78 ± 1.70 for FAc, and 190.23 ± 1.50 for PCAc. The antioxidant activity was estimated by: 1,1-diphenyl-2-picrylhydrazyl (DPPH), nitric oxide scavenging activity (NO) and β-carotene bleaching method (β-carotene). The values expressed as percentage correspond to FAc and PCAc, respectively. DPPH: 86.30 ± 1.1 and 88.83 ± 1.2; NO: 29.38 ± 1.9 and 48.75 ± 1.7; andβ-carotene: 83.00 ± 1.8 and 44.60 ± 1.5. The histopathological diagnosis indicates that casein-fed rats present moderate fat infiltration in the liver, whereas in PCAc-fed rats, the liver has structural integrity. The presence of phenols would provoke an increase of the antioxidant defenses and would produce a protective role in liver. It is suggested that Ac could be a good antioxidant source. PRACTICAL APPLICATIONS A number of epidemiological studies initially indicated the utility of antioxidants in disease prevention, particularly for cardiovascular disease and cancer. This association is often attributed to different antioxidant components, such as polyphenols, vitamin C, vitamin E, carotenoids and other phytochemicals. Amaranth species are receiving special attention in developing countries as an alternative to tackle protein deficiencies in diets. At present, some studies have been conducted on amaranth antioxidant activity (AA). Furthermore, protein concentrates, as nutritional sources, also exhibit physiological effects. In order to understand the protective effect of natural compounds, in vitro studies of antioxidant components must be conducted, followed by an assessment of their antioxidant function. Our results are a contribution to research into new sources of natural antioxidants in this and other related species, and we hope that they will enhance the national food composition database.