Reducing Power Values Research Articles

Biological Potential of Alternative Kombucha Beverages Fermented on Essential Oil Distillation By-Products

The complete waste streams (solid waste residue, wastewater, and hydrolate) from the essential oil production of basil, chamomile, lavender, rosemary, and hyssop plants were used as a cultivation media for fermentations of a health-beneficial beverage called kombucha. Considering that these waste streams have not been used as a medium for obtaining kombucha, the main focus of this study was on the biological profiling and sensory analysis of newly-obtained kombucha beverages. According to fermentation parameters and advanced mathematical modelling, it can be concluded that kombucha made from chamomile essential oil by-products achieved the fastest successful kombucha fermentation, with a maximal titratable acidity of 7.2 g/L and a minimal pH value of 2.8. The results of other kombucha fermentations varied between the chosen plant and the waste stream used for beverage production. The obtained phenol and flavonoid contents were in the range of 12.4–56.46 mg GA/100 mL and 0.25–5.07 mg RU/100 mL, respectively. Higher antioxidant capacity as well as anti-inflammatory and antihyperglycemic activities of all kombucha beverages were observed compared to controls. Briefly, achieved DPPH, ABTS, and reducing power values were in the range 30.28–73.70, 192.25–683.29, and 19.37–82.76 mmol TE/100 mL, respectively. According to sensory analysis, the best performance or complete acceptability was noted for kombucha beverages made from lavender and hyssops (in the case of solid waste stream mixed with hydrolate) as well as basil (in the case of concentrated wastewater and hydrolate).

Nanomechanical, Structural and Antioxidant Characterization of Nixtamalized Popcorn Pericarp

Expanded popcorn grain is widely consumed as a healthy snack all around the world; however, the study of the behavior of its components by processes such as nixtamalization is scarce. Therefore, the aim of this work was to characterize the nanomechanical, structural, and antioxidant properties of nixtamalized popcorn grain pericarp. FT-IR results showed that the secondary structure of proteins of the nixtamalized pericarp was α-helix with 42.10%, the turn was 21.5% and 36.33% β-sheet, and proteins of the pericarp did not present the random coil structure. Pericarp showed antioxidant activity, as their values were 550.1 ± 2.9 and 44.2 ± 1.6 (TE)/mL for ABTS and DPPH, respectively; total phenols content was 0.21 ± 0.008 (TE)/mL; reducing power values were around 29 to 31%; hydroxyl radical scavenging ranged from 36 to 55% and iron chelation around 115 to 140% compared to the standard acids. Thickness values of the nixtamalized pericarp by SEM image analysis were 0.15 ± 0.1 mm near the pedicel inferior tip, 0.07 ± 0.01 mm at middle, and 0.03 ± 0.02 mm at upper of the grain. Young’s modulus value was 261.72 ± 23.58 MPa with a Gaussian function fitting at the distribution of all values. This research provides novel and valuable information for understanding the nanomechanical and protein arrangement, as well as and the antioxidant activity of nixtamalized popcorn grain pericarp in order to promote other processes and uses for this kind of pericarp maize.

How does Flourensia microphylla extract affect polyphenolic composition, antioxidant capacity, and antifungal activity?

Tomato (Solanum lycopersicum L.) fruit is one of the most popular vegetables worldwide, as it is widely consumed due to its many nutrients and antioxidants. Fusarium oxysporum and Alternaria alternata are two phytopathogenic fungi that attack tomato in the field and postharvest. To control them, synthetic chemical fungicides are used; however, the fungi develop resistance to them, and they can cause damage to human health and the environment. Therefore, research on plant polyphenolic extracts with fungicidal potential has increased. Flourensia microphylla has shown antifungal activity in vitro against different phytopathogens; however, the extraction process is a main factor affecting this activity. Ultrasound-assisted extraction (UAE) has been reported to increase the bioactivity of plant extracts. Based on the above, the aims of the present study were to evaluate how F. microphylla extract affects polyphenolic composition, antioxidant capacity, and antifungal activity. A total of 9 F. microphylla extracts were obtained by UAE, and a control extract was obtained by conventional extraction. The yield, total phenolic and flavonoid contents (TPC and TFC, respectively), antioxidant activities by three methods, and polyphenol identification by high-performance liquid chromatography (UHPLC) of the extracts were evaluated. The antifungal activity of the extract was evaluated in vitro against F. oxysporum and A. alternata, for which an extract treatment was selected considering the treatment that obtained the highest TFC and antioxidant activity values as a criterion. As a result, three phenolic acids and six flavonoids were detected in the extract treatments: gallic, 4-hydroxybenzoic and ferulic acids, catechin, naringin, quercetin, kaempferol, isorhamentin and chrysin. In addition to reducing the extraction times, the treatment that was selected corresponded to a solvent-to-sample ratio of 40 mL/g and an extraction time of 20 min. The selected extract resulted in an extraction yield of 23.4 g/100 g dry weight (DW), TPC of 252.8 mg gallic acid equivalents (GAE)/g DW, and TFC of 435.9 mg quercetin equivalents (QE)/g DW. For antioxidant activities, the 2,2-diphenyl 1-picrylhydrazyl (DPPH), 2,2-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and reducing power values were 74.2, 740.4 mM Trolox/g DW and 33.0 mg ascorbic acid/g DW, respectively. Moreover, the F. microphylla treatment selected inhibited 87.72 % of the mycelial growth of F. oxysporum and 100 % of that of A. alternata, demonstrating fungistatic and fungicidal activity, respectively, in the fungi under study. Thus, the phenolic extract obtained by UAE increased the contents of phenolic compounds, mainly flavonoids, as well as antioxidants, which potentiated the bioactivity of F. microphylla against phytopathogenic fungi. In addition, the antifungal activity could be attributed to the presence of flavonoid compounds identified in the selected polyphenolic extract.

Streptomyces barringtoniae sp. nov., isolated from rhizosphere of plant with antioxidative potential.

A novel actinomycete strain, JA03T, belonging to the genus Streptomyces, was isolated from the rhizosphere of Barringtonia racemosa (L.) Spreng. It was characterized taxonomically using a polyphasic approach. It grew at 25-37 °C, at pH 5-10 and with 6 % (w/v) NaCl. It contained ll-diaminopimelic acid in the cell-wall peptidoglycan. Ribose and glucose were detected in its whole-cell hydrolysate. The predominant cellular fatty acids were iso-C16 : 0, anteiso-C15 : 0, C16 : 0, iso-C14 : 0 and iso-C15 : 0. Detected polar lipids were phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, phosphatidylinositol mannosides, unidentified phospholipids and unidentified amino lipids. Based on the results of 16S rRNA gene sequence analyses, strain JA03T showed highest similarity to Streptomyces filipinensis NBRC 12860T (98.76 %), Streptomyces fodineus TW1S1T (98.69 %) and Streptomyces shenzhennensis 172115T (98.68 %). Strain JA03T has a genome size of 9 092 851 bp with DNA G+C content of 71.28 mol%. The average nucleotide identity (ANI)-blast and ANI-MUMmer values of strain JA03T and related type strains were 79.6-89.2 and 86.7-92.5 %, respectively, and the digital DNA-DNA hybridization values were 27.3-46.4 %. Ethyl acetate extract of JA03T exhibited total phenolic content (33.4±0.6 µg mg-1 gallic acid equivalent), ferric reducing power value (70.8±1.8 µg mg-1 ascorbic acid equivalent) and 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity (IC50=67.0±21.1 µg ml-1). Intracellular reactive oxygen species and NO production in RAW264.7 macrophage cells induced by H2O2 and lipopolysaccharide were inhibited with IC50 of 67.40 and 16.95 µg ml-1, respectively. Based on the taxonomic results, it has been concluded that strain JA03T represents a novel species of the genus Streptomyces for which the name Streptomyces barringtoniae sp. nov., is proposed. The type strain is JA03T (=LMG 32415T=TISTR 2999T).

Effect of Rosa pimpinellifolia Extract on Human Tumor Cells Proliferation

The genus Rosa belongs to the Rosaceae family and contains more than 100 species which are distributed in Europe, Asia, the Middle East and North America. Rosa species have long been used in traditional treatment of cold, infections and various inflammatory diseases. Although various studies have reported antioxidant, antidiabetic, anti-inflammatory, renoprotective and anticancer activities of this genus, no previous studies have investigated the cytotoxic effect of Rosa pimpinellifolia on human cancer cells. The aim of this study was to evaluate the antioxidant properties of R. pimpinellifolia and its cytotoxic effect against human colon (WiDr), liver (HepG2) and lung (A549) cancer cells compared with a normal fibroblast (BJ) cell line. The antioxidant properties of extract was determined using colorimetric methods, while the cytotoxic effect of extract was evaluated using MTT assay. The total phenolic content and reducing power values of extract were calculated as 16.4±0.4 mg gallic acid equivalent and 34.3±2.4 mg trolox equivalent per g sample, respectively. Although the extract exhibits selective cytotoxic effect on three cancer cell lines in a dose-dependent manner compared to BJ cells, the highest selectivity index value (2.7-fold) was obtained for the WiDr cell line. In conclusion, this is the first study to demonstrate the cytotoxic effect of R. pimpinellifolia on cancer cells. To demonstrate the molecular mechanism of this cytotoxic effect and to carry out in vivo studies may be a guide for future clinical studies.

Structural features, chemical composition, antioxidant activities of organosolv lignins extracted from black and white sesame capsules and stalks

Sesame is an industrial crop widely planted in China. Sesame capsules and stalks are by-products of sesame oil production. The production of these byproducts is large, but their utilization rate is low. As lignocellulosic biomass, sesame stalks and capsules contain plentiful amounts of lignin. In this study, the ethanol organosolv method was used to isolate lignin from black sesame capsules (BSL-1) and stalks (BSL-2), and white sesame capsules (WSL-1) and stalks (WSL-2). In order to promote full utilization of these lignins, their structural features and chemical composition were investigated and are here reported for the first time; antioxidant capacities were also analyzed. Among the four lignin fractions, the yield of BSL-1 was highest (53.94%). Capsules (47.04%-53.94%) consistently yielded more lignin than stalks (40.23%–40.90%). The predominant monosaccharides associated with BSL-1, WSL-1, and WSL-2 (i.e., all except BSL-2) were glucose. BSL-2 showed the highest thermal stability with the highest molecular weight. A similar composition ratio of linkages (β-O-4', β-β', and β-5') was observed in BSL-1 and WSL-1, and in BSL-2 and WSL-2. All the lignins belong to the GSH type and had S/G ratio values (2.36–3.05) greater than 2.0. Antioxidant studies showed that BSL-1 had the highest DPPH scavenging activity (RSI = 3.31), WSL-2 had the highest ABTS scavenging activity (RSI = 16.31), and WSL-1 had the highest reducing power values. The current study advances understanding of the structural differences of organosolv lignin from sesame capsules and stalks and should promote their future applications.

Evaluation of Cytotoxic Effect of Onosma armeniacum Extract on Various Cancer Cells

The aim of this study was to investigate the antioxidant properties of the root extract of Onosma armeniacum and its cytotoxic effect against human liver (HepG2), lung (A549) and colon (WiDr) cancer cell lines compared with a normal fibroblast cell line. Antioxidant properties of the extract was determined using the colorimetric methods. The cytotoxic effect of the extract were investigated using MTT assay. The total phenolic content and reducing power values of extract were 26.1±0.4 mg gallic acid equivalent and 52.6±1.1 mg trolox equivalent per g sample, respectively. The extract exhibited selective cytotoxic effect in all studied cancer cell lines, especially HepG2 (3.6-fold). The results of this study reveal that O. armeniacum, which has been found to have acceptable antioxidant and cytotoxic effects, should be examined with more comprehensive studies.

Tea polyphenols increase the antioxidant status of laying hens fed diets with different levels of ageing corn.

This study was conducted to evaluate the effects of ageing corn levels (stored for 4 years) with or without the supplementation of tea polyphenols (TPP) on the performance, egg quality and antioxidant status of laying hens. A total of 288 Lohmann commercial laying hens (63-week-old) were used under a 2 × 4 factorial arrangement with 4 levels of dietary ageing corn (0%, 25%, 50%, or 100%) and 2 levels of TPP (0 and 600 mg/kg) for 8 wk. Dietary ageing corn linearly decreased (P < 0.05) the egg production, serum total antioxidant capacity (T-AOC), liver glutathione peroxidase (GSH-Px) of laying hens, yolk index, yolk colour, 1,1-diphenyl-2-picrylhydrazyl (DPPH) value and the reducing power value of egg yolk, but it linearly increased (P < 0.05) the feed conversion rate, ovary malondialdehyde (MDA) content of laying hens, and the protein carbonyl content of egg yolk. Tea polyphenol supplementation increased (P < 0.05) the serum T-AOC, serum superoxide dismutase (SOD), liver SOD, liver GSH-Px, ovary SOD, GSH-Px, the expression of antioxidant-related genes of laying hens, albumen height, Haugh unit, DPPH value and the majority free amino acids of egg yolk, but it decreased (P < 0.05) the serum MDA content of laying hens, MDA and protein carbonyl of egg yolk. In conclusion, the ageing corn significantly reduced the performance, egg quality, antioxidant status and egg antioxidant capacity of laying hens, while TPP supplementation partially counteracted the adverse effects, especially antioxidant status and egg antioxidant capacity of laying hens.

Effect of steaming and frozen storage on polyphenol content and antioxidant properties of Mangifera odorata (Kuini) pulp

Mangifera odorata (kuini) is a potential source of antioxidant. As a seasonal fruit and easily perishable after harvesting, production of kuini pulp was a common practice to overcome this problem. Steaming treatment were involved in the production of kuini pulp before being stored at -18°C. These thermal treatment and storage are challenging due to the fact that it can induce changes of antioxidants properties of kuini pulp. Thus, this study evaluated the effect of steaming processing and frozen storage on the total phenolic content (TPC) and antioxidant activity (AOA) measured by ferric reducing antioxidant power (FRAP) and DPPH radical scavenging activity (RSA) method of M. odorata (kuini) pulps. Overall, a significant difference was observed for TPC and AOA for steaming kuini pulp compared to control samples. Steaming processing significantly increased the TPC and AOA of the kuini pulps (p &lt; 0.05). Significant relationships (p &lt; 0.05) were identified between total phenolics and total antioxidant activities. Storage at -18°C significantly affected the TPC and AOA of the frozen kuini pulp samples. After 12 months storage of all frozen kuini pulp samples, phenolics content was decreased up to 34%; the reducing power value decreased up to 50%, and DPPH RSA decreased up to 35% of the initial value. Steam blanching is recommended to enhance the phenolic content and the antioxidant but, frozen storage at -18°C cannot preserve the phenolic content and the antioxidant of kuini pulp.

Radical scavenging and antioxidant features of nano-pomegranate (Punica granatum L.) peel powder extracts

The replacement of synthetic antioxidants with natural antioxidants from agricultural waste has become a global interest due to their adverse effects on human health. Nanotechnology can facilitate the extraction of natural compounds. In this study, the preparation and characterization of nano-pomegranate peel powder fractions and their extracts were described. The nano-fractions (NPP45 and NPP90) were prepared by ultrafine grinding of the crude pomegranate peel powder (CPP) for 45 and 90 min. Extracts using different solvents were subjected to determine total phenolics (μg gallic acid equivalent (GAE)/ml extract), 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity (RSA), reducing power (RP), ferric reducing antioxidant power (FRAP). Polynomial quadratic regression was employed to calculate the predicted optimal RSA and FRAP and protective factor (PF) values. The mean particle size of NPP45 and NPP90 were 373 and 125nm, respectively. NPP90 methanolic extract had the highest phenolics content of 1.54 ± 0.04 μg GAE/ml compared to the methanolic CPP extract that contained 1.18 ± 0.03 μg GAE/ml with a 30.5% increase. The RSA, PF, RP and FRAP values were 94.1 ± 0.2%, 2.6, 0.76 ± 0.03 and 0.76 ± 0.03, respectively for the NPP90 methanolic extract. NPP90 methanolic extract reflected antiradical and antioxidant efficiency which was comparable with the efficiency of BHT (153.1 ppm). The results from the study showed potential replacement for BHT as a synthetic antioxidant with the natural NPP90 phenolics. This is the first time that an attempt has been done towards the extraction of phenolic compounds from pomegranate peels using nanotechnology.

A UHPLC-QTOF-MS screening provides new insights into the phytochemical composition and biological properties of six Consolida species from Turkey

The genus Consolida is one of the most important within the Ranunculaceae family and several members of this genus contain important biologically active compounds, such as phenolics and alkaloids. The present study attempts for the first time to assess the biological properties and phytochemical constituents of six Consolida species (C. glandulosa (Boiss. & A. Huet) Bornm, C. hellospontica (Boiss.) Chater, C. raveyi (Boiss.) Schrödinger, C. regalis (Boiss.) Schrödinger, C. staminosa P.H. Davis & Sorger and C. stenocarpa (P.H. Davis & M. Hossain) P.H. Davis) growing in Turkey. A comprehensive phytochemical profiling of the different species was achieved by using an ultra-high-performance liquid chromatography-quadrupole time-of-flight (UHPLC-QTOF) mass spectrometry, targeting polyphenols and diterpene alkaloids. Also, the in vitro antioxidant assays (2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid (ABTS), ferric reducing antioxidant power (FRAP), cupric reducing antioxidant capacity (CUPRAC), metal chelating and phosphomolybdenum) and enzyme inhibition (cholinesterases, tyrosinase, α-amylase, and α-glucosidase) potentials of the different Consolida methanolic extracts were evaluated. The UHPLC-QTOF profiling revealed 492 compounds, being 236 flavonoids, 93 phenolic acids, 78 tyrosol derivatives, 49 diterpene alkaloids, 29 lignans, and 7 stilbenes. The cumulative phenolic content ranged from 17.65 mg Eq./g for C. staminosa up to 43.04 mg Eq./g for C. glandulosa, whilst the total diterpene alkaloids content was exclusively found in C. glandulosa extracts (3.53 mg Eq./g). Consolida regalis (58. 61 mg trolox equivalent (TE)/g for DPPH and 65.38 mg TE/g for ABTS) and C. stenocarpa (46.81 mg TE/g for DPPH and 78.12 mg TE/g for ABTS) exhibited the highest anti-radical abilities, while the best reducing power values were recorded for C. glandulosa (129.46 mg TE/g for CUPRAC and 77.01 mg TE/g for FRAP) and C. raveyi (124.56 mg TE/g for CUPRAC and 78.36 mg TE/g for FRAP). Also, following the cholinesterases inhibition assays, C. hellospontica and C. glandulosa exhibited the highest inhibitory effects. Regarding tyrosinase inhibitory effects, C. raveyi showed the highest value, being 126.60 mg kojic acid equivalent (KAE)/g, followed by C. glandulosa (125.82 mg KAE/g) and C. stenocarpa (123.09 mg KAE/g). Besides, Consolida staminosa showed potential inhibition against α-amylase, but low glucosidase inhibitory properties. Therefore, the present findings could provide a starting point for further investigations to promote the industrial exploitation of these species with the aim of designing novel phyto-pharmaceuticals.

Combined Effect of Sonication and Acid Whey on Antioxidant and Angiotensin-Converting Enzyme Inhibitory Activities of Peptides Obtained from Dry-Cured Pork Loin

This study aimed to determine the effects of sonication and acid whey maceration on the oxidative stability, antioxidant activity and angiotensin-converting enzyme (ACE) inhibitory activity of peptides obtained from dry-cured pork loins. The changes in the selected parameters were documented over 7, 21 and 42 days of storage. The lowest antioxidant and angiotensin-converting enzyme inhibitory activities of peptides were noted in batches with curing salt (C) and acid whey (SW) compared to batches with sea salt (S). In this sample range, the lowest oxidation–reduction power values were associated with the use of ultrasound. In addition, higher antiradical activity (against ABTS•+) and reducing power values were observed for the sea salt ultrasound (SU) batches (after 21 and 42 days) and for the acid whey ultrasound (SWU) batches (after 7 and 21 days). Contrasting results were obtained for samples with sea salt (S and SU), which were characterized by a higher content of peptides, better antiradical properties and the highest potential to inhibit ACE (after seven days).

PHYTOCHEMICAL IDENTIFICATION AND ANTIOXIDANT ACTIVITY OF PASSIFLORA FOETIDA FRUITS AND LEAVES EXTRACTS: A COMPARATIVE STUDY

Objective: The objective of this study was to compare the phytochemical composition and antioxidant activity of Passiflora foetida fruits and leaves extract.&#x0D; Methods: The parameters observed in this study were phytochemical compounds including alkaloid, flavonoid, phenolic, sterol, triterpenoid, saponin, tannin, and cardiac glycoside, total phenolic content Folin Ciocalteu method is based on reduction of Folin Ciocalteu reagent in alkaline medium; the metal complex produced measured at λmax: 760 nm; total flavonoids content with AlCl3 Colorimetric method based on complex formation of AlCl3 and flavonoid content in alkaline medium, the AlCl3-flavonoid complex produced measured at λmax: 510 nm; free radical DPPH scavenging activity; and ferric reducing power based on reduction of Fe3+ion into Fe2+ion that reacted with FeCl3 to form a ferric-ferrous complex that measured at λmax: 700 nm.&#x0D; Results: Passiflora leaves extract has phytochemical compound such as alkaloids, phenolics, flavonoids, saponins, and cardiac glycosides, total phenol was 22.92±0.18 mg GAE/g sample dry base, total flavonoid was 7.01±0.10 mg CE/g sample dry base, DPPH scavenging activity was 2.77±0.02 mg GAE/g sample dry base and ferric reducing power was 3.20±0.04 mg GAE/g sample dry base meanwhile Passiflora fruits extract had phytochemical compounds such as alkaloid, phenolic, flavonoids, cardiac glycosides, total phenol was 6.53±1.02 mg GAE/g sample dry base, total flavonoids were 1.56±0.27 mg CE/g sample dry base, DPPH free radical scavenging activity was 1.00±0.15 mg GAE/g sample dry base, and ferric reducing power was 1.12±0.17 mg GAE/g sample dry base.&#x0D; Conclusion: Passiflora leaves extract has higher total phenol, total flavonoid and antioxidant activity measured by DPPH scavenging activity and ferric reducing power value compared with Passiflora fruits extract.

Values of antioxidant activities (ABTS and DPPH) and ferric reducing and chelating powers of gamma-irradiated rosemary extract

Abstract This study was carried out to evaluate the effect of the various gamma dose irradiations on the antioxidant activity of rosemary PBS (phosphate-buffered saline) extract. The PBS extract of rosemary was irradiated with gamma rays at the doses of 10, 20, 30, 40 and 50 kGy, and their antioxidant activities were investigated by DPPH (1,1-diphenyl-2-picrylhydrazyl), radical cation ABTS•+ (2,2-Azino-Bis (3-Ethylbenzthiazoline-6-Sulfonic Acid), Diammonium Salt), ferric reducing antioxidant power assay (FRAP) and ferric chelating capacity using ferrozine. The scavenging activities of gamma irradiated rosemary were observed to be significantly higher at 30 and 40 kGy using both methods, DPPH and ABST. Also, the reducing power values of 30 kGy gamma irradiated rosemary were higher than that of non-irradiated (P &lt; 0.05) and the other doses of irradiation could not make any significant difference in reducing power of non-irradiated rosemary. The gamma irradiation of rosemary (at 10–50 kGy), significantly increased the Fe2+ chelating activity compared to non-irradiated rosemary while increasing the absorbed doses reduced Fe2+ chelating activity in rosemary (P &lt; 0.05). There is no significant difference in the rosemary irradiated with 10 kGy and 30 kGy. The gamma irradiated rosemary showed higher antioxidant activities at doses of 30 kGy (79.5 %) and 40 kGy (80 %) with DPPH method, while slightly lower activities were recorded at doses of 30 kGy (34.8 %) and 40 kGy (34.2 %) with ABTS test. Also, results indicate that the 30 kGy might be an effective dose with maximum enhancement in the antioxidant properties of the gamma irradiated rosemary.

Estimation of the antioxidant properties of milk protein preparations hydrolyzed by Lactobacillus helveticus T80, T105 and B734

The investigation determined the influence of Lactobacillus helveticus strains (T80, T105, B734 and DSMZ 20075) and Lactobacillus acidophilus La-05 (probiotic strain) on the antioxidant activity of whey and milk protein preparations. In order to indicate possible mechanism of antioxidant activity of the obtained hydrolysates, the reducing power (RP) assay, ability to neutralize free radicals and Fe2+ chelating activity analysis were employed. The results suggest that antioxidant activity of tested hydrolysates depends on the type of protein preparation (substrate) and the applied bacterial strain. The strongest antioxidant activity was exhibited by whey protein isolate hydrolysate obtained by using L. helveticus T80. A majority of fermented products obtained with the use of the probiotic strain were characterized by higher antioxidant properties than those obtained by application of L. helveticus. The solution of caseinoglicomacropeptide fermented by strain T105 exhibited the highest RP values, while α-lactalbumin hydrolysed by probiotic strain (La-5) was characterized by the strongest Fe2+ chelating activity. The analysed protein preparations and their hydrolysates obtained with using tested bacteria might potentially be applied in food products in order to inhibit oxidation processes.

Antioxidant activity and identification of food proteins by digestive enzyme supplementation and fermentation with Lactobacillus kefiri

Casein, gluten, and soy protein are widely used in food processing for structure, texture, and flavour improvement. These large proteins might be hydrolysed to shorter peptides or amino acids, which provide antioxidant activities through enzymatic and fermentative food processes. Casein, gluten, and soy protein were digested with an enzyme supplement product containing dipeptidyl peptidase IV (DPPIV) and protease in this study. Then, each protein was hydrolysed by Lactobacillus kefiri strain. 2,2, diphenyl 1-picryl hydrazyl (DPPH) radical scavenging activity and reducing power (RP) were measured for undigested and digested samples. According to our results, all proteins were hydrolysed. Soy protein demonstrated the highest IC&lt;sub&gt;50&lt;/sub&gt; value of DPPH for undigested (2.64 mg/ml) and digested samples (1.56 mg/ml) as well as the highest RP value (0.171 for undigested and 0.234 for digested at 700 nm). On the other hand, casein provided the weakest DPPH radical scavenging activity (1.58 ± 0.041% for undigested and 21.86 ± 0.012% for digested samples). A strong correlation was found between cell growth and antioxidant activity of casein during the microbial fermentation. In addition, the changes in protein expression levels by microbial fermentation were analysed by using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Mass spectrometry-based protein identification studies revealed that EF-G, DNA-K, and DNA-J were mainly overexpressed indicating L. kefiri adapts itself by changing the overall proteome.

Effect of frost on flavonol glycosides accumulation and antioxidant activities of mulberry (Morus alba L.) leaves

Background: Both Pharmacopoeia of the People's Republic of China and the ancient Chinese herbal formulas recorded that mulberry leaves collected after frost had good quality. However, the reason has not yet been fully elucidated. Objective: We investigated the effect of frost on the accumulation of flavonoids and antioxidant activities of mulberry leaves. Materials and Methods: Liquid chromatography-mass spectrometry and high-performance liquid chromatography were used to analyze chemical components and determine the content of five flavonol glycosides from mulberry leaves collected before and after frost, respectively. Antioxidant activities of the same mulberry leaves were evaluated by total antioxidant capacity (TAC), Fe2+ equivalent (FeE), reducing power (RP), 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging assay, and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid (ABTS) free radical scavenging assay. Results: Ten compounds were identified as flavonol glycosides exception of chlorogenic acid. Quantitative analysis showed that content of isoquercitrin, astragalin, and kaempferol-3-O-(6''-acetyl)-β-D-glucopyranoside reached a maximum of 3.05 mg/g, 0.70 mg/g, and 0.69 mg/g after Frost's Descent, respectively. Moreover, the lowest value of flavonol glycosides appeared in August. The antioxidant activities were also found to have the same tendency. The maximum value of TAC, FeE, RP, DPPH and ABTS were 64.3 rutin equivalent (RE) mg/g, 46.2 RE mg/g, 31.3 RE mg/g, 22.5 RE mg/g and 26.7 RE mg/g, respectively, in November. They were 1.4 times, 1.4 times, 1.6 times, 1.6 times, and 1.9 times of the minimum values, respectively, in August. There was a significantly and positively correlation between antioxidant activities and content of flavonol glycosides (P

Rhododendron luteum Yaprak Ekstraktının İnsan Kanser Hücre Serilerindeki Sitotoksik Etkisi

Rhododendron luteum belongs to the genus Rhododendron, members of which are frequently used in folk medicine. Various studies have investigated the cytotoxic effect of different Rhododendron species, but there have been limited studies of the cytotoxic effect of R. luteum. The aim of this study was to investigate the antioxidant properties and cytotoxic effect of R. luteum leaf extract on the human cancer cells. The total phenolic content (TPC), total flavonoid content (TFC), and reducing power of the extract were evaluated using spectrophotometric procedures. The cytotoxic effect of the extract on five cancers (human breast, colon, lung, prostate, and liver carcinoma) and human fibroblast cells was determined using the MTT assay. TPC and reducing power values of extract were found 173.2±3.97 mg gallic acid equivalents, and 629.5±3.49 mg trolox equivalents per to g sample, respectively. R. luteum leaf extract exhibited selective cytotoxicity especially against colon (1.9 fold) and liver (2.2 fold) cancer cells compared to normal fibroblast cells. This is the first study to reveal the antiproliferative effect of R. luteum leaf extract. Further studies are now needed to identify the cytotoxic molecules in the extract and their mechanisms.

Individual and combined effects of drought and heat on antioxidant parameters and growth performance in Buffel grass (Cenchrus ciliaris L.) genotypes

Drought and heat stress are two critical threats to crop growth and sustainable agriculture worldwide. In the last decade, many studies focused on the response of crops to a single stress, nevertheless studying the response of plants to a combination stress may be critical to our understanding of stress tolerance in plants and the development of tolerant genotypes. Buffel grass (Cenchrus ciliaris L.) is a warm-season grass known in arid and semiarid regions for its tolerance to heat and drought stress, productivity, and forage quality. However, in our previous works, several accessions have exhibited different responses to abiotic stresses. Therefore, the objective of this work was to evaluate the effects of combination of drought and heat stresses on biochemical parameters and plant growth and to compare the impacts of the stresses separately and when combined. We found that sensitive genotype exhibited higher lipid peroxidation content, lower total reducing power values and reduced catalase and superoxide dismutase activities than tolerant under drought or heat stress or combination stress. In this study, heat stress had a predominant effect on buffel grass genotypes over drought stress, which explained why simultaneous application of heat and drought revealed similar biochemical and growth responses to the heat stress. Antioxidant metabolism seems to be critical for tolerate abiotic stress. This study may provide useful information to perform a rapid and low-cost characterization in new buffel grass germplasm and to identify genotypes with better growth performance under drought and heat conditions.

Assessing phenolic content and antioxidant potential diversity in Allium plants using multivariate data analysis

The genus Allium includes hundreds of plant species and is regarded as one of the most cultivated vegetables. It is an important source of novel therapeutic compounds known for their beneficial effects on human health; however, there could be differences in content, composition, type, and bioactivity of the phytochemicals found among the Allium plants. The main purpose of this study was to acquire insights on the variation in antioxidant profiles and phenolic content between Allium accessions in different species, as well as between similar species of several varieties. We collected 112 accessions from more than 20 countries, and grew them under similar agronomic conditions. The antioxidant potential was evaluated by using 2,2′-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS), 1,1-diphenyl-1-picrylhydrazyl (DPPH), ferric reducing antioxidant power (FRAP), and reducing power (RP) assays. The total phenolic content (TPC) was studied using the Folin–Ciocalteu method. TPC varied from 3.43 (accession 199897) to 22.19 (accession 273483) µg gallic acid equivalent/mg dry weight (DW) of the aerial organs of Allium. The antioxidant activity of Allium samples ranged from 4.37 (accession 806595) to 57.46 (accession number 711971) µg Trolox equivalent/mg DW; 0.35 (accession 117246) to 9.53 (accession 711971) µg ascorbic acid equivalents/mg DW; 2.92 (accession 199890) to 21.20 (accession 803493) µgAAE/mg DW; and 0.80 (accession 117260) to 31.13 (accession 803527) µgAAE/mg DW using ABTS, DPPH, FRAP, and RP assays, respectively. Accessions 273483 (A. cepa), 283346 (A. cepa ‘cepa’), and 803527 (unknown species) had the highest TPC, FRAP, and RP values among those tested, while the highest ABTS and DPPH radical scavenging activities were recorded in accession 711971 (A. ramosum). Pearson’s coefficient of correlations indicated that variables (TPC, ABTS, DPPH, FRAP, and RP values) correlated significantly each other, with r-values between 0.585 and 0.894. Principal component analysis plots and hierarchical cluster analysis indicated significant variability in antioxidant activity and phenolic content among all the accessions studied, as well as within similar species. Based on our results from principal component and hierarchical cluster analysis, accession 283346 (A. cepa ‘cepa’), K139348 (A. fistulosum), and 711971 (A. ramosum) are potential sources of phenolics and natural antioxidants. The variability in total phenolic and antioxidant activity among the Allium accessions can be used by breeders, food technologists, nutritionist, and researchers for assessing breeding lines for genetic selection and for monitoring levels of these factors during food storage and processing.