μM Trolox Equivalent Antioxidant Capacity Research Articles

Electrospun Poly-ε-Caprolactone Nanofibers Incorporating Keratin Hydrolysates as Innovative Antioxidant Scaffolds.

This manuscript describes the development and characterization of electrospun nanofibers incorporating bioactive hydrolysates obtained from the microbial bioconversion of feathers, a highly available agro-industrial byproduct. The electrospun nanofibers were characterized using different instrumental methods, and their antioxidant properties and toxicological potential were evaluated. Keratin hydrolysates (KHs) produced by Bacillus velezensis P45 were incorporated at 1, 2.5, and 5% (w/w) into poly-ε-caprolactone (PCL; 10 and 15%, w/v solutions) before electrospinning. The obtained nanofibers were between 296 and 363 nm in diameter, showing a string-like morphology and adequate structural continuity. Thermogravimetric analysis showed three weight loss events, with 5% of the mass lost up to 330 °C and 90% from 350 to 450 °C. Infrared spectroscopy showed typical peaks of PCL and amide bands corresponding to keratin peptides. The biological activity was preserved after electrospinning and the hemolytic activity was below 1% as expected for biocompatible materials. In addition, the antioxidant capacity released from the nanofibers was confirmed by DPPH and ABTS radical scavenging activities. The DPPH scavenging activity observed for the nanofibers was greater than 30% after 24 h of incubation, ranging from 845 to 1080 µM TEAC (Trolox equivalent antioxidant capacity). The antioxidant activity for the ABTS radical assay was 44.19, 49.61, and 56.21% (corresponding to 972.0, 1153.3, and 1228.7 µM TEAC) for nanofibers made using 15% PCL with 1, 2.5, and 5% KH, respectively. These nanostructures may represent interesting antioxidant biocompatible materials for various pharmaceutical applications, including wound dressings, topical drug delivery, cosmetics, and packaging.

Novel Coconut Vinegar Attenuates Hepatic and Vascular Oxidative Stress in Rats Fed a High-Cholesterol Diet.

BackgroundHypercholesterolemia is an independent modifiable risk factor that accelerates the development of both non-alcoholic fatty liver and atherosclerosis. Coconut water contains a variety of phytochemicals that make it appealing for producing vinegar. Coconut vinegar is rapidly gaining popularity for health benefits in Southeast Asia. The purpose of this study is to evaluate the effect of daily supplementation of coconut vinegar on hepatic and vascular oxidative stress in rats fed a high-cholesterol diet (HCD).MethodsMature coconut water was fermented with coconut sap sugar using Saccharomyces cerevisiae and Acetobacter aceti vat Europeans, respectively. Bioactive compounds and antioxidant capacity of coconut vinegar were examined in vitro. Adult male Sprague–Dawley rats were randomly divided into four groups; the control group fed a standard diet (S), a group that received HCD (SC), a group that received HCD supplemented with coconut vinegar at a dose of 1 mL/kg/day (SCV), and a group that received HCD with atorvastatin at a dose of 30 mg/kg/day (SCA). After 8 weeks, serum metabolic profiles, fatty liver, hepatic, and vascular oxidative stress were determined.ResultsIn in vitro studies, coconut vinegar was rich in phenolic compounds and organic acids. The antioxidant capacity of 30 μL of coconut vinegar was 181.55 ± 8.15 μM Trolox equivalent antioxidant capacity (TEAC). In the HCD fed rats, daily supplementation of coconut vinegar reduced weight gain, serum triglycerides, and fasting blood sugar levels without renal or liver toxicity. In the liver, coconut vinegar reduced the accumulation of both hepatic cholesterol and hepatic triglyceride, and it also reduced hepatic 4-hydroxynonenal (4-HNE) lipid peroxidation. In the aortic tissues, coconut vinegar increased nitric oxide bioavailability and reduced aortic 4-HNE lipid peroxidation.ConclusionNovel coconut vinegar is the source of antioxidants, and daily supplementation of coconut vinegar was found to attenuate dyslipidemia-induced hepatic and vascular oxidative stress by protective against cellular lipid peroxidation.

Determination of Antioxidant Activity of Different Extracts From Bark of Pinus spp. grown in Giresun (Turkey) Province – Phenolic analysis by RP-HPLC-DAD

This study aimed to investigate the phenolic compounds, total phenolic content, and antioxidant activities of Pinus sylvestris L. var hamata Steven, Pinus pinaster Aiton subsp. pinaster, and Pinus pinea L. bark extracts prepared with hot water. The phenolic composition and total phenolic content (TPC) of extracts were determined by Reversed Phase-High Performance Liquid Chromatography-Diode Array Detector (RP-HPLC-DAD) and Folin–Ciocâlteu method, respectively. The antioxidant activity was determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH•) radical scavenging and ferric ion (III) reducing / antioxidant power (FRAP) assays. Besides, the highest total phenolic content was detected in P. pinea bark extract [984.46±4.08 μg mL-1 gallic acid equivalent (GAE) and 1163.33±4.04 μg mL-1 catechin equivalent (CE)] and the lowest result was detected in P. sylvestris bark extract (361.53±3.52 μg mL-1 GAE and 427.26±4.17 μg mL-1 CE). Among the tested materials, the most abundant phenolic compounds in P. pinea bark extract were catechin (3.586±0.114 mg g-1) and taxifolin (1.866±0.096 mg g-1). According to the antioxidant results, P. pinea bark extract exhibited remarkable antioxidant activity than standard BHT and Trolox [SC50: 1.64310±0.00003 µg mL-1 for DPPH and 1428.75±5.62 µM Trolox Equivalent Antioxidant Capacity (TEAC) for FRAP]. The obtained results indicated that pine bark extracts can be used as an easily obtainable natural source of antioxidants for the food and pharmaceutical industry.

GC-MS analyses and bioactivities of essential oil obtained from the roots of Chrysopogon zizanioides (L.) Roberty cultivated in Giresun, Turkey

The essential oils (EOs) constituents have trade importance due to their bioactivities. In this research, the essential oil of the roots of Chrysopogon zizanioides (L.) Roberty cultivated in Giresun was obtained by hydrodistillation. Then, the chemical composition and biological activities of Chrysopogon zizanioides root essential oil (CEO) were studied. Thirty compounds were identified by gas chromatography-mass spectrometry (GC-MS) and the major compounds were determined as isobutyl-angelate (11.15%), α-muurolene (10.56%), α-cedrene (8.42%), α-patchoulene (8.10%), and ethylene brassylate (7.49%). The antimicrobial effect of CEO was investigated against pathogenic bacteria and fungus. Minimal inhibition concentration (MIC) was determined 31.25 μg/mL against C. albicans and between 62.5 and 125 μg/mL against the rest of the microorganisms. According to the antioxidant assays, the total phenolic content of CEO was found to be 13.70 ± 2.10 μg/mL gallic acid equivalent (GAE) and 24.67 ± 3.79 μg/mL catechin equivalent (CE). Ferric reducing/antioxidant power (FRAP) of CEO was found to be 356.44 ± 2.34 μM Trolox equivalent antioxidant capacity (TEAC). 2,2-diphenyl-1-picrylhydrazyl (DPPH?) was determined as IC50 to be 7.124 ± 0.076 μg/mL. According to the obtained results, CEO has significant antimicrobial and antioxidant activities. This study is the first report determining the chemical composition, antimicrobial and antioxidant activities of essential oil obtained from vetiver grown in the Black Sea Region of Turkey.

Phenolic compounds, essential oil composition, and antioxidant activity of Angelica purpurascens (Avé-Lall.) Gill.

In this study, methanol extracts (MEs) and essential oil (EO) of Angelica purpurascens (Avé-Lall.) Gill obtained from different parts (root, stem, leaf, and seed) were evaluated in terms of antioxidant activity, total phenolics, compositions of phenolic compound, and essential oil with the methods of 2,2-azino-bis(3ethylbenzo-thiazoline-6-sulfonic acid (ABTS•+), 2,2-diphenyl-1-picrylhydrazil (DPPH•) radical scavenging activities, and ferric reducing/antioxidant power (FRAP), the Folin–Ciocalteu, liquid chromatography−tandem mass spectrometry (LC−MS/MS), and gas chromatography-mass spectrometry (GC−MS), respectively. The root extract of A. purpurascens exhibited the highest ABTS•+, DPPH•, and FRAP activities (IC50: 0.05 ± 0.0001 mg/mL, IC50: 0.06 ± 0.002 mg/mL, 821.04 ± 15.96 µM TEAC (Trolox equivalent antioxidant capacity), respectively). Moreover, EO of A. purpurascens root displayed DPPH• scavenging activity (IC50: 2.95 ± 0.084 mg/mL). The root extract had the highest total phenolic content (438.75 ± 16.39 GAE (gallic acid equivalent), µg/mL)). Twenty compounds were identified by LC−MS/MS. The most abundant phenolics were ferulic acid (244.39 ± 15.64 μg/g extract), benzoic acid (138.18 ± 8.84 μg/g extract), oleuropein (78.04 ± 4.99 μg/g extract), and rutin (31.21 ± 2.00 μg/g extract) in seed, stem, root, and leaf extracts, respectively. According to the GC−MS analysis, the major components were determined as α-bisabolol (22.93%), cubebol (14.39%), α-pinene (11.63%), and α-limonene (9.41%) among 29 compounds. Consequently, the MEs and EO of A. purpurascens can be used as a natural antioxidant source.

Callus Culture of Thai Basil Is an Effective Biological System for the Production of Antioxidants.

Thai basil is a renowned medicinal plant and a rich source of bioactive antioxidant compounds with several health benefits, with actions to prevent of cancer, diabetes and cardiovascular disease. Plant cell and tissue culture technologies can be routinely established as an important, sustainable and low-cost biomass source to produce high-value phytochemicals. The current study aimed at developing an effective protocol to produce Thai basil leaf-derived callus cultures with sustainable and high production of biomass and antioxidants as an alternative of leaves production. MS basal medium with various concentrations of plant growth regulators (PGRs) compatible with nutraceutical applications (i.e., gibberellic acid (GA3) and 6-benzylaminopurine (BAP) either alone or in combination with naphthalene acetic acid (NAA)) were evaluated. Among all tested PGRs, the combination BAP:NAA (5 mg/L:1 mg/L) yields the maximum biomass accumulation (fresh weight (FW): 190 g/L and dry weight (DW): 13.05 g/L) as well as enhanced phenolic (346.08 mg/L) production. HPLC quantification analysis indicated high productions of chicoric acid (35.77 mg/g DW) and rosmarinic acid (7.35 mg/g DW) under optimized callus culture conditions. Antioxidant potential was assessed using both in vitro cell free and in vivo cellular antioxidant assays. Maximum in vitro antioxidant activity DPPH (93.2% of radical scavenging activity) and ABTS (1322 µM Trolox equivalent antioxidant capacity) was also observed for the extracts from callus cultures grown in optimal conditions. In vivo cellular antioxidant activity assay confirmed the effective protection against oxidative stress of the corresponding extract by the maximum inhibition of ROS and RNS production. Compared to commercial leaves, callus extracts showed higher production of chicoric acid and rosmarinic acid associated with higher antioxidant capacity. In addition, this biological system also has a large capacity for continuous biomass production, thus demonstrating its high potential for possible nutraceutical applications.

Carbonic anhydrase enzyme inhibition and biological activities of Satureja hortensis L. essential oil

Recently, there is a great need to discover new natural carbonic anhydrase (CA) inhibitor sources to be used as diuretic, antiglaucoma, anti-obesity, anticancer, and anti-infective drugs. Therefore, evaluation of CA inhibition activity and possible inhibition mechanism of the essential oil of Satureja hortensis L. (SHEO) were investigated for the first time by this study. Additionally, total phenolic content known effective for CA inhibition and the other biological activities was determined for the first time. Since the volatile compound and total phenolic content of essential oil of S. hortensis grown in Bingöl exhibited great differences than those in the literature, the antioxidant and antimicrobial activities of SHEO were also investigated. Carbonic anhydrase inhibition of SHEO was determined as IC50: 0.1 ± 0.002 μg/mL. Further, molecular docking studies between the main volatile compounds and CA have been conducted to better understand the CA inhibition mechanism of SHEO. The main compounds were as β-decalol (19.10%), perillaldehyde (17.11%), perillyl alcohol (16.87%), carvacrol (13.47%), and thymol (12.32%) by GC-MS. β-decalol was detected in an essential oil for the first time. Based on the molecular docking studies, thymol and β-decalol showed great potential for CA inhibition. Besides, total phenolic content was determined as 623 ± 2.88 μg/mL gallic acid equivalent (GAE) and 736 ± 3.46 μg/mL catechin equivalent (CE). The essential oil showed high antioxidant capacity [(SC50: 0.069 ± 0.283 μg/mL for 2,2-diphenyl-1-picrylhydrazyl (DPPH•) and 1031 ± 5.03 μM trolox equivalent antioxidant capacity (TEAC) for ferric reducing power (FRAP)]. The essential oil also showed significant antimicrobial activity against six Gram-positive and six Gram-negative bacteria, and a fungus. Minimal inhibitory concentrations (MICs) were 15.6 μg/mL and 31.2 μg/mL for MRSA ATCC 67101 and C. albicans, respectively. The rest of eleven bacteria exhibited MICs between 3.9-7.8 μg/mL. Consequently, SHEO could be used as antioxidant and antimicrobial agent at very low concentrations. In addition, SHEO significantly inhibited CA, thus, SHEO was a promising source for CA inhibitors and it might have potential to be used for treatment of CA related diseases.

Antioxidant and cytotoxic potential of leaf extracts of Costus igneus

Background: Costus igneus leaves are traditionally used to treat diabetes and this plant is commonly known as insulin plant. Hypothesis: The purpose of this study was to evaluate the antioxidant and cytotoxic potential of different leaf extracts of C. igneus. Materials and Methods: The antioxidant potential of various leaf extracts of C. igneus was established by ferric reducing antioxidant power (FRAP) assay, 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assay, metal-chelating activity, phosphomolybdenum assay, superoxide radical scavenging activity, 2,2-diphenylpicrylhydrazyl (DPPH) assay, reducing power assay, and cytotoxic activity by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay on breast cancer cell line Michigan Cancer Foundation (MCF-7). Results: In FRAP assay, acetone extract showed higher activity of 276.31 mmol Fe (II) E/mg extract. In ABTS assay, hexane extract showed the highest scavenging activity of 12878.893 μM Trolox equivalent antioxidant capacity (TEAC)/g extract. Hot water extract registered higher metal ion-chelating ability with 2.94 mg ethylenediaminetetraacetic acid equivalent/g extract. Hexane extract has recorded the highest total antioxidant capacity of 65.00 mg AAE/mg in phosphomolybdenum assay. Superoxide radical scavenging activity was found maximum in acetone extract with 41.11%. In DPPH assay, acetone extract recorded total free radical scavenging capacity with IC50 value of 40.70 μg/ml. Hexane extract has recorded significant highest reducing power at concentration 100 μg/μl with maximum optical density of 0.177. Acetone extract of C. igneus leaf extract at concentration of 150 μg/ml showed the highest cytotoxic activity on cancer cell line with cell viability of 65.51%. Conclusion: The present study explored that C. igneus shows efficient antioxidant activity as well as cytotoxic activity and could act as safe and cost-effective with potential biological applications.

Extraction efficiency, phytochemical profiles and antioxidative properties of different parts of Saptarangi (Salacia chinensis L.) – An important underutilized plant

The study aimed to evaluate extraction efficiency, detection and quantification of phytochemicals, minerals and antioxidative capacity of different parts of Salacia chinensis L. Continuous shaking extraction, steam bath assisted extraction, ultrasonic extraction and microwave assisted extraction with varied time intervals were employed for extraction of phenolics, flavonoids, and antioxidants. Preliminary screening revealed the presence of wide array of metabolites along with carbohydrates and starch. Steam bath assisted extraction for 10min exposure was found most suitable for extraction phenolics (46.02 ± 2.30mg of gallic acid equivalent per gram of dry weight and 48.57 ± 2.42mg of tannic acid equivalent per gram of dry weight) and flavonoids (35.26 ± 1.61mg of quercetin equivalent per gram of dry weight and 51.60 ± 2.58mg of ellagic acid equivalent per gram of dry weight). In support, reverse phase-high performance liquid chromatography- diode array detector confirmed the presence of seven pharmaceutically important phenolic acids. Antioxidant capacity was measured by 1, 1- diphenyl-1-picryl hydrazyl (DPPH), ferric reducing antioxidant power (FRAP), 2, 2′-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) scavenging (ABTS) and N, N-dimethyl-p-phenylenediamine (DMPD) assays and represented as trolox equivalent antioxidant capacity (TEAC) and ascorbic acid equivalent antioxidant capacity (AEAC). Antioxidant capacity ranged from 121.02 ± 6.05 to 1567.28 ± 78.36µM trolox equivalent antioxidant capacity and 56.62 ± 2.83 to 972.48 ± 48.62µM ascorbic acid equivalent antioxidant capacity. Roots showed higher yields of illustrated biochemical parameters, however fresh fruit pulp was found a chief source of minerals. Gas chromatography-mass spectroscopic analysis revealed the presence of a vast array of phytoconstituents associated with different plant parts. The present study revealed the amounts of minerals and diverse phytoconstituents in various parts of S. chinensis and confirmed its medicinal and nutritional implications.

Antiproliferative and antioxidant activity of xanthohumol acyl derivatives

A series of mono- and diacyl- xanthohumol (1) derivatives was synthesized with yields of 10–30%. All the compounds were tested against the antiproliferative activity of human cancer cell line of colon adenocarcinoma (HT-29) using SRB assay. The most active (IC50 values < 12 μM) were three compounds: 4-O-acetylxanthohumol (2) (IC50 = 11.84 μM), 4,4′-Di-O-acetylxanthohumol (3) (IC50 = 11.75 μM) and 4-Odecanoylxanthohumol (4) (IC50 = 10.04 μM). For the starting compound xanthohumol (1) IC50 = 9.74 μM. The antioxidant activity was determined by the method of 2.2-diphenyl-1-picrylhydrazyl radical and 2,2′-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid and expressed as μM of Trolox equivalent antioxidant capacity per gram. Only one compound 4-O-acetylxanthohumol (2) (15 μM Trolox equivalent antioxidant capacity for 2,2-diphenyl-1-picrylhydrazyl radical and 160 μM Trolox equivalent antioxidant capacity for 2,2′-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid methods) showed a lower antioxidant activity compared to xanthohumol (1) (38 μM Trolox equivalent antioxidant capacity for 2,2-diphenyl-1-picrylhydrazyl radical and 19 μM Trolox equivalent antioxidant capacity for 2,2′-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid methods). Other tested compounds showed comparable or higher antioxidant activity as xanthohumol (1).

English

The present study aimed to determine the content of minerals, bioactive compounds and the antioxidant activity of ‘Cajui’ (Anacardium humille St. Hill) during the ripening. The fruits were collected in three maturity stages. The content of the minerals, total phenolics, proanthocyanidin and carotenoids contents as well as the antioxidant activity, ABTS (2,2-azinobis-3-ethylben-zothiazoline-6-sulphonic acid), DPPH (2,2-diphenyl-1-picrylhydrazyl) and FRAP (ferric reducing antioxidant power) were determined, with results expressed on Trolox equivalent antioxidant capacity (TEAC). The Student’s t-test was employed to analyse the data, based on a significance level of p < 0.05. The total phenolic contents were determined as 1424.33 ± 28.62, 991.16 ± 21.52 and 867.08 ± 28.56 mg GAE.100 g-1 for the immature, semi-mature and mature stages, respectively. Regarding the carotenoid content, 18.05 ± 1.01 was obtained for the immature stage, 8.62 ± 0.96 was obtained for the semi-mature stage, and 8.32 ± 0.97 mg-β-carotene.100 g-1 was obtained for the mature stage. Regarding the antioxidant activity; it was particularly relevant for the fruits in the immature stage in the three methods used: DPPH (30399.63 ± 27.06 µM TEAC.100g-1), ABTS (40860.62 ± 9.32 µM TEAC 100 g-1) and FRAP (6118.22 ± 83.04 µM TEAC.100 g-1). The ‘cajui’ exhibited high antioxidant activity and content of bioactive compounds, especially for the immature stage. Among the minerals, ‘cajui’ showed high levels of K (potassium), P (phosphorus), and Mg (magnesium). Thus, the cajui presents itself as a good source of antioxidant compounds which can be exploited by the food industry as an ingredient for the development of a food with functional properties and the pharmaceutical industry, as phytochemical. Key words: Minerals, phenolic compounds; maturation stages; antioxidant activity.