Oxygen Radical Absorbance Capacity Values Research Articles

Exploring the potential of high hydrostatic pressure and ionic polysaccharides in improving interfacial stability of sweet potato protein hydrolysate emulsions

SummaryThis study aims to explore the potential of high hydrostatic pressure (HHP, 300–500 MPa) and ionic polysaccharides (sodium alginate, SA; chitosan, CH) in improving interfacial stability of sweet potato protein hydrolysate (SPPH) emulsions. HHP markedly improved emulsifying performance of SPPH with SA and CH at different concentrations (0.02% and 0.06%, w/v) and enhanced the apparent viscosities of their emulsions. SPPH‐CH0.02% at 400 MPa showed the highest emulsifying stability index (ESI, 255.96 min) and zeta potential absolute value (54.13 mV), and its emulsion exhibited the highest adsorbed peptide and CH at interface (31.72% and 1.51%, respectively) and oxygen radical absorbance capacity (ORAC) value of interfacial layer (264.56 μg TE mL−1). Additionally, multiple potential antioxidant peptides were obtained from interfacial layer of emulsion stabilised with SPPH‐CH0.02% at 400 MPa through LC‐MS/MS, and the relationship between their structure and emulsion stability was analysed. Therefore, HHP has great application potential in production of SPPH‐CH emulsion with enhanced stability.

Antioxidant compounds produced by endolichenic fungus Penicillium sp.-strain 1322P isolated from Pyxine subcinerea.

Endolichenic fungi are expecting for new bioresources of pharmacological compounds. However, the number of investigations targeting antioxidant compounds produced by endolichenic fungi remains limited. To discover new antioxidant compounds, we analyzed the antioxidant activity of the methanol extracts derived from isolated lichen mycobionts or endolichenic fungi induced from Pyxine subcinerea. We performed this analysis using the oxygen radical absorbance capacity (ORAC) method. As a result, we isolated from an endolichenic fungus identified as Penicillium sp.-stain 1322P in Pyxine subcinerea. This fungus produced a red pigment, and its chemical structure was determined to be sclerotioramine based on the analytical data obtained from NMR, LC-MS/MS, and HPLC-PDA. Sclerotioramine exhibited high antioxidant activity, and the ORAC values (mean ± SD) of sclerotioramine and sclerotiorin were 11.4 ± 0.36 and 4.86 ± 0.70 mmol TE per gram of the respective pure compound. Thus, the antioxidant activity of sclerotioramine was greater than twice that of sclerotiorin. This work represents the first report that the antioxidant activity of sclerotioramine is higher than that of the sclerotiorin.

Therapeutic Potential of Bacteroides fragilis SNBF-1 as a Next-Generation Probiotic: In Vitro Efficacy in Lipid and Carbohydrate Metabolism and Antioxidant Activity.

This study explores the potential of aerotolerant Bacteroides fragilis (B. fragilis) strains as next-generation probiotics (NGPs), focusing on their adaptability in the gastrointestinal environment, safety profile, and probiotic functions. From 23 healthy infant fecal samples, we successfully isolated 56 beneficial B. fragilis strains. Notably, the SNBF-1 strain demonstrated superior cholesterol removal efficiency in HepG2 cells, outshining all other strains by achieving a remarkable reduction in cholesterol by 55.38 ± 2.26%. Comprehensive genotype and phenotype analyses were conducted, including sugar utilization and antibiotic sensitivity tests, leading to the development of an optimized growth medium for SNBF-1. SNBF-1 also demonstrated robust and consistent antioxidant activity, particularly in cell-free extracts, as evidenced by an average oxygen radical absorbance capacity value of 1.061 and a 2,2-diphenyl-1-picrylhydrazyl scavenging ability of 94.53 ± 7.31%. The regulation of carbohydrate metabolism by SNBF-1 was assessed in the insulin-resistant HepG2 cell line. In enzyme inhibition assays, SNBF-1 showed significant α-amylase and α-glucosidase inhibition, with rates of 87.04 ± 2.03% and 37.82 ± 1.36%, respectively. Furthermore, the cell-free supernatant (CFS) of SNBF-1 enhanced glucose consumption and glycogen synthesis in insulin-resistant HepG2 cells, indicating improved cellular energy metabolism. This was consistent with the observation that the CFS of SNBF-1 increased the proliferation of HepG2 cells by 123.77 ± 0.82% compared to that of the control. Overall, this research significantly enhances our understanding of NGPs and their potential therapeutic applications in modulating the gut microbiome.

Autochthonous Fermentation as a Means to Improve the Bioaccessibility and Antioxidant Activity of Proteins and Phenolic Compounds of Yellow Pea Flour.

This study focused on evaluating the potential of the natural fermentation of pea flour to improve the release of antioxidant compounds. Preliminary fermentations of 36.4% w/w flour dispersions were performed in tubes under different conditions (24 and 48 h, 30 and 37 °C). Finally, fermented flours (FFs) were obtained in a bioreactor under two conditions: 1: 36.4% w/w, 24 h, 30 °C (FF1); 2: 14.3% w/w, 24 h, 37 °C (FF2). The pH values decreased to 4.4-4.7, with a predominance of lactic acid bacteria. As in the fermentations in tubes, an increment in the proteolysis degree (TNBS method) (greater for FF2), polypeptide aggregation and a decrease in their solubility, an increase in <2 kDa peptides, and an increase in the Oxygen Radical Absorption Capacity (ORAC) potency of PBS-soluble fractions after fermentation were demonstrated. Also, fermentation increased the proteolysis degree after simulated gastrointestinal digestion (SGID, COST-INFOGEST) with respect to the non-fermented flour digests, with some differences in the molecular composition of the different digests. ORAC and Hydroxyl Radical Averting Capacity (HORAC) potencies increased in all cases. The digest of FF2 (FF2D) presented the greater ORAC value, with higher activities for >4 kDa, as well as for some fractions in the ranges 2-0.3 kDa and <0.10 kDa. Fermentation also increased the 60%-ethanol-extracted phenolic compounds, mainly flavonoids, and the ORAC activity. After SGID, the flavan-3-ols disappeared, but some phenolic acids increased with respect to the flour. Fermentation in condition 2 was considered the most appropriate to obtain a functional antioxidant ingredient.

In-Vitro Bioactivity Evaluation of Hydrangenol Extracted from Hydrangea macrophylla (Thunb.) Ser. Leaves

Hydrangea macrophylla plant, native to Japan and Korea, has been attracting scientific attention due to its potential applications in both food science and health-related research. In this investigation, dry Hydrangea leaves were utilized as the source material. Subsequent to comminution and thermal treatment at 70 °C for an 18-hour duration, followed by a 30-minute ultrasonic bath extraction and a 5-minute centrifugation at 5000 rpm, hydrangenol was isolated through preparative HPLC. The investigation involved assessing the antioxidant capacity of hydrangenol, its impact on the activity of α-amylase and α-glucosidase enzymes, and its ability to prevent enzymatic browning. Quantification of antioxidant capacity, determined through TEAC (Trolox Equivalent Antioxidant Capacity), showed values from 1.8 to 3.2 mmol TE/mmol. Likewise, the ORAC (Oxygen Radical Absorbance Capacity) values were in the range of 16.5-27.0 mmol TE/mmol. Total phenolics content (Folin-Ciocalteu test) yielded a range of 7.1-11.2 g GAE (Gallic Acid Equivalents) per 100 g. Examining α-amylase inhibition, hydrangenol demonstrated a 52% inhibition (IC50: 3.6 mg/mL), whereas acarbose (positive control) displayed a higher inhibition of 99 % (IC50: 0.51 mg/mL). Regarding α-glucosidase inhibition, hydrangenol exhibited a 51% inhibition (IC50: 0.97 mg/mL), while acarbose displayed a 46% inhibition (IC50: 2.1 mg/mL). Additionally, the activity of PPO was suppressed by 61% at hydrangenol concentrations of 1 mg/mL and 2 mg/mL, and by 46% at a concentration of 4 mg/mL.

Membrane-Based Preparation Process and Antioxidant and Anti-AGEs Activities of a Novel Propolis Ultrafiltrate.

Propolis is one functional supplement with hundreds of years of usage. However, it's rarely consumed directly for its resinous property. Herein, a pre-treated process which can remove the impurity while preserve its bioactivities is needed to maximise its therapeutic opportunities. In the present study, a membrane-based ultrafiltration process was developed on a KM1812-NF experimental instrument. Using Brazilian green propolis as testing material, all experimental steps and parameters were sequentially optimized. In addition, a mathematical model was developed to fit the process. As a result, the optimum solvent was 60 % ethanol adjusted to pH 8-9, while the optimum MWCO (molecular weight cut-off) value of membrane was 30 KDa. The membrane filtration dynamic model fitted with the function y=(ax+b)/(1+cx+dx2 ). The resulting propolis ultrafiltrate from Brazilian green propolis, termed P30K, contains the similar profile of flavonoids and phenolic acids as raw propolis. Meanwhile, the ORAC (oxygen radical absorbance capacity) value of P30K is 11429.45±1557.58 μM TE/g and the IC50 value of inhibition of fluorescent AGEs (advanced glycation end products) formation is 0.064 mg/mL. Our work provides an innovative alternative process for extraction of active compounds from propolis and reveals P30K as an efficient therapeutic antioxidant.

Antioxidant Capacity of Free and Peptide Tryptophan Residues Determined by the ORAC (Oxygen Radical Absorbance Capacity) Assay Is Modulated by Radical-Radical Reactions and Oxidation Products.

The ORAC (Oxygen Radical Absorbance Capacity) assay is commonly employed for determining the antioxidant capacity of bioactive peptides. To gain insights into the meaning of this index for peptides containing a single Trp, we studied the consumption of this residue and fluorescein (FLH, the probe of ORAC method), induced by radicals generated by AAPH (2,2'-Azo-bis(2-amidinopropane) dihydrochloride) thermolysis. ORAC values were rationalized from kinetics and computational calculations of bond dissociation energies (BDE) of the N-H bond (indole ring of Trp). Free Trp, di- and tri- peptides, and three larger peptides were studied. Solutions containing 70 nM FLH, 1-5 μM free Trp or peptides, and 10 mM AAPH were incubated at 37 °C in phosphate buffer. Kinetic studies showed that FLH minimally affected Trp consumption. However, a clear protection of FLH, characterized by pseudo-lag times, was evidenced, reflecting radical-radical reactions and FLH repairing. Peptides showed similar ORAC values (~1.9-2.8 Trolox equivalents), while BDE varied between 91.9 and 103.5 kcal. These results, added to the protection of FLH observed after total consumption of Trp, indicate a lack of discrimination of the assay for the chemical structure of peptides and the contribution of oxidation products to the index.

Syzigium aromaticum may protect against paraquat mediated toxicity via p53 and Sestrin2 modulation

AbstractBackgroundNumerous environmental risk factors, particularly neurotoxins, have been linked to the development of sporadic Parkinson’s disease (PD), even though its exact cause is still unknown. The common spice Syzigium aromaticum has the greatest ORAC (Oxygen Radical Absorbance Capacity) value according to the National Institute on Aging. One of the three components of healthy ageing, vata, is calmed by Syzigium aromaticum while also stimulates nerves. The study investigated the rescue effect of Syzigium aromaticum ethanolic extract against paraquat (PQ) mediated PD type toxicity and elucidated the underlying molecular mechanism using the cell line.MethodThe cold extraction method was used to prepare the Syzigium aromaticum ethanolic extract by powdering, soaking in ethanol and stirring for 72 h. Then the supernatant was gradually aliquoted and filtered with Whatman filter paper no 1. Paraquat, at different doses, was used to generate PD type toxicity in SH‐SY5Y cells for 24, 48, and 72 hours, and MTT test was used to measure the cytotoxicity. The rescue effect was demonstrated by simultaneously treating cells with 100 mM PQ and various doses of Syzigium aromaticum and then performing MTT assay. The protein expression studies was done using western blot technique to elucidate the underlying mechanism.ResultThe toxicity experiment showed that PQ‐treated cells exhibited significant cell death, with the maximal toxicity occurring after 72 hours. However, the cells treated with Syzigium aromaticum were protected from the PQ‐induced cell death. Syzigium aromaticum exhibited rescue effect in proportion to its dose. The western blot analysis of PQ treated SH‐SY5Y cells demonstrated a dose‐dependent increase in the levels of p53, Setrin2, and phosphorylated AMPK (P‐AMPK). The levels of AMPK, mTOR and p70S6K remain unchanged, however, the phosphorylated p70S6K (P‐p70S6K) levels were declined. When cells were simultaneously treated with PQ and increasing dose of Syzigium aromaticum, the levels of p53, Sesn2, and P‐AMPK lowered similar to control. Further, there was an increase in the level of phosphorylated p70S6K (P‐p70S6K) in proportion to the dose of Syzigium aromaticum.ConclusionThe current study showed that the Syzigium aromaticum ethanolic extract prevented PQ‐induced cell death in SH‐SY5Y by targeting p53 and sestrin2.

Evaluation of Crocin Content and In Vitro Antioxidant and Anti-Glycation Activity of Different Saffron Extracts.

Crocin, a glycoside carotenoid that exhibits several health benefits, is mainly obtained from saffron (Crocus sativus L.), whose quality and content of phytochemicals can be strongly affected by environmental conditions. Therefore, in this work, the crocin content and in vitro antioxidant activity of saffron extracts obtained from three different varieties (Greek, Sicilian, and Iranian saffron) were assessed. Crocin content in saffron extracts was quantified via ultra-performance liquid chromatography coupled with mass spectrometry. The antioxidant activity of saffron extracts was evaluated using the oxygen radical absorbance capacity (ORAC) assay and nitric oxide (NO) radical scavenging test. The Maillard reaction was used to assess anti-glycation activity. Although the Sicilian and Iranian saffron extracts contained higher amounts of crocin (128 ± 6 ng/mL and 126 ± 4 ng/mL, respectively) compared to the Greek extracts (111 ± 2 ng/mL), ORAC values (50.9 ± 0.5) and % NO inhibition (35.2 ± 0.2) were higher for the Greek variety, which displayed a total phenolic content about two-fold greater than that of the other two extracts. Sicilian and Greek saffron had similar anti-glycation activities, while Iranian saffron was less effective. These results suggest that the antioxidant activity of saffron extracts could be ascribed to their naturally occurring complex mixture of phytochemicals, deserving further investigation as supplements to prevent pathological conditions induced by radical species.

Antioxidant Activity of Different Hop (Humulus lupulus L.) Genotypes.

The antioxidant activity (AA) of hop extracts obtained from different hop genotypes (n = 14) was studied. For comparison, the purified β-acids-rich fraction and α-acids-with-β-acids-rich fraction were also used to test the antioxidative potential. The AA of purified hydroacetonic hop extracts was investigated using the Ferric Reducing Ability of Plasma (FRAP), Oxygen Radical Absorption Capacity (ORAC) and Intracellular Antioxidant (IA) methods. The FRAP values in different hop genotypes ranged between 63.5 and 101.6 μmol Trolox equivalent (TE)/g dry weight (DW), the ORAC values ranged between 1069 and 1910 μmol TE/g DW and IA potential values ranged between 52.7 and 118.0 mmol TE/g DW. Significant differences in AA between hop genotypes were observed with all three methods. AAs were determined using three different methods, which did not highly correlate with each other. We also did not find significant correlations between AA and different chemical components, which applies both to AA determined using individual methods as well as the total AA. Based on this fact, we assume that the synergistic or antagonistic effects between hop compounds have a more pronounced effect on AA than the presence and quantity of individual hop compounds.

A standardized extract of Echinacea purpurea containing higher chicoric acid content enhances immune function in murine macrophages and cyclophosphamide-induced immunosuppression mice

Context Preparations of Echinacea have been used by herbalists to boost the immune system. Objective In this study, Echinacea purpurea (L.) Moench (Asteraceae) extract with enriched chicoric acid content was investigated for immunomodulation. Materials and methods The standardized hydroalcoholic extract (4% chicoric acid) was prepared from the aerial parts of E. purpurea (SEP). The extract was screened for in vitro antioxidant activities, and immunomodulation in RAW 264.7 cells, at 200 and 400 µg/mL. Further, the male BALB/c mice (20-25 g) were divided into 4 groups (n = 6 per group). All the groups except control, were intraperitoneally injected with 70 mg/kg/day of cyclophosphamide (CTX) for 4 consecutive days. The treatment groups received SEP extract (100 and 200 mg/kg body weight) p.o. from day 5 to 14. Results The SEP extract inhibited DPPH (IC50 = 106.7 µg/mL), ABTS+ (IC50 = 19.88 µg/mL) and nitric oxide (IC50 = 120.1 µg/mL). The SEP extract’s ORAC (oxygen radical absorbance capacity) value was 1931.63 µM TE/g. In RAW 264.7 cells, SEP extract increased the nitric oxide production by 30.76- and 39.07-fold at 200 and 400 µg/mL, respectively, compared to the untreated cells. SEP extract significantly increased phagocytosis and cytokine release (TNF-α, IL-6, and IL-1β) in the cells. Further, the extract improved immune organ indices, lymphocyte proliferation and serum cytokine levels in CTX-induced mice. The extract at 200 mg/kg significantly increased the natural killer cell activity (24.6%) and phagocytic index (28.03%) of CTX mice. Conclusion Our results strongly support SEP extract with 4% chicoric acid as a functional ingredient for immunomodulation.

Insights into tissue-specific anthocyanin accumulation in Japanese plum (Prunus salicina L.) fruits: A comparative study of three cultivars

In the present study, three matured Japanese plum cultivars with different colored peel and flesh were selected to mine the key transcription factors regulating anthocyanin formation in tissues. Results showed that PsMYB10 was correlated with structural genes C4H, F3H, and ANS. PsMYB6 could positively regulate C4H (r = 0.732) and accumulated anthocyanins in Sanhua plum’s flesh. Sanhua plum has the highest phenolic and anthocyanin contents (10.24 ± 0.37 gallic acid equivalent mg g−1 dry weight (DW) and 68.95 ± 1.03 μg g−1 DW), resulting itself superior biological activity as 367.1 ± 42.9 Trolox equivalent mg g−1 DW in oxygen radical absorbance capacity value and 72.79 ± 4.34 quercetin equivalent mg g−1 DW in cellular antioxidant activity value. The present work provides new insights into the regulatory mechanism of tissue-specific anthocyanin biosynthesis, confirming the pivotal role of anthocyanins in the biological activity of plums, providing essential support for the development of horticultural products enriched with anthocyanins.

Elaboration of the Effective Multi-Target Therapeutic Platform for the Treatment of Alzheimer's Disease Based on Novel Monoterpene-Derived Hydroxamic Acids.

Novel monoterpene-based hydroxamic acids of two structural types were synthesized for the first time. The first type consisted of compounds with a hydroxamate group directly bound to acyclic, monocyclic and bicyclic monoterpene scaffolds. The second type included hydroxamic acids connected with the monoterpene moiety through aliphatic (hexa/heptamethylene) or aromatic linkers. An in vitro analysis of biological activity demonstrated that some of these molecules had powerful HDAC6 inhibitory activity, with the presence of a linker area in the structure of compounds playing a key role. In particular, it was found that hydroxamic acids containing a hexa- and heptamethylene linker and (-)-perill fragment in the Cap group exhibit excellent inhibitory activity against HDAC6 with IC50 in the submicromolar range from 0.56 ± 0.01 µM to 0.74 ± 0.02 µM. The results of the study of antiradical activity demonstrated the presence of moderate ability for some hydroxamic acids to scavenge 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2ROO• radicals. The correlation coefficient between the DPPH radical scavenging activity and oxygen radical absorbance capacity (ORAC) value was R2 = 0.8400. In addition, compounds with an aromatic linker based on para-substituted cinnamic acids, having a monocyclic para-menthene skeleton as a Cap group, 35a, 38a, 35b and 38b, demonstrated a significant ability to suppress the aggregation of the pathological β-amyloid peptide 1-42. The 35a lead compound with a promising profile of biological activity, discovered in the in vitro experiments, demonstrated neuroprotective effects on in vivo models of Alzheimer's disease using 5xFAD transgenic mice. Together, the results obtained demonstrate a potential strategy for the use of monoterpene-derived hydroxamic acids for treatment of various aspects of Alzheimer's disease.

Dietary total antioxidant capacity and serum 8-OHdG in patients with schizophrenia.

Dietary total antioxidant capacity serves as an indicator for dietary quality and reflects daily antioxidant intake. This study aimed to determine the oxidative stress status of patients with schizophrenia and to examine the relationship between dietary total antioxidant capacity (dTAC) and 8-hydroxy-2'-deoxyguanosine (8-OHdG), a marker for oxidative stress. This study was conducted in Turkey and involved 40 patients diagnosed with schizophrenia or schizoaffective disorder according to the Diagnostic and Statistical Manual of Mental Disorders, 5th ed., and 30 healthy controls matched for age and gender. The participants' sociodemographic characteristics and nutritional habits were determined through face-to-face interviews and through the use of questionnaires. The dTAC and dietary oxidative balance scores were calculated using a three-day dietary intake record. 8-OHdG levels were analyzed in the serum samples collected from the subjects. Dietary ferric reducing antioxidant power (FRAP-1, FRAP-2), Trolox equivalence antioxidant capacity (TEAC), and oxygen radical absorbance capacity (H-ORAC) values were lower in patients with schizophrenia than in the healthy controls (P < 0.05). Serum 8-OHdG levels were found similar in both groups (P > 0.05). Nutritional interventions are needed in patients with schizophrenia given that insufficient antioxidant intake may increase oxidative stress, which in turn affects disease development. Therefore, healthy nutrition, especially sufficient intake of dietary antioxidants, should be encouraged in patients with schizophrenia.

Global Patterns of Antioxidant-Rich Food Crops Based on Geographical Origins

We mapped antioxidant values of 118 common food crops at a global scale based on geographical origins using median oxygen radical absorbance capacity (ORAC) and total phenolics (TP) for twenty-three regions to evaluate broad-scale patterns. Using the U.S. Department of Agriculture Food Composition Database we used k-means clustering to differentiate regions based on ORAC and TP values. Latitude is positively associated with ORAC (r s = 0.51, p < 0.02) and TP (r s = 0.48, p < 0.02) with the highest values found in northeastern Europe, North America, and temperate South America. The lowest ORAC values are associated with equatorial and subtropical regions. Latitudinal differences in antioxidant properties of crops are positively associated with cold stress in the promotion of higher ORAC and TP values in colder regions. Latitudinal pattern exceptions occur in southwestern Europe where maritime conditions moderate cold stress and in the Andes where high-elevation conditions promote cold stress. Global evaluation of crop antioxidants reveals distinct geographical patterns that incorporate the long- and short-term effects of anthropogenic activity. Our findings suggest that results from smaller scale studies are operative at broader (regional-level) scales despite the influence of crop domestication and dispersal of crops across floristic boundaries.

Antioxidant potential of the diet in Italian children with food allergies.

A reduced fruit and vegetable consumption, which implies a decreased intake of antioxidant compounds, seems to play a role in allergic diseases onset. Data on the antioxidant capacity of diet in children with food allergies, who are on an avoidance diet, are still lacking. This pilot study aims to assess the antioxidant potential of diet in Italian children with food allergies, compared to healthy children, using the oxygen radical absorbance capacity (ORAC) method. 95 children (54 with confirmed food allergies and 41 controls), with a median age of 7.8 years, were enrolled and underwent a nutritional assessment. Mean nutrient intakes were compared using the Mann-Whitney test. ORAC resulted significantly lower in allergic children (median 2,908, IQR: 1450;4,716) compared to control children (median 4,392, IQR: 2523;5,836; p = 0.049). Among micronutrients with antioxidant properties, vitamin A intakes were significantly higher in controls than in allergic children. Using Spearman's correlation, a moderate-to-strong correlation between ORAC and vitamin C, potassium and magnesium was observed (ρ = 0.648, p < 0.001; ρ = 0.645, p < 0.001; ρ = 0.500, p < 0.001, respectively). Iron, phosphorus, vitamin E and vitamin A intakes were also moderately-to-low correlated with ORAC values (ρ = 0.351, p < 0.001; ρ = 0.367, p < 0.001; ρ = 0.346, p < 0.001; and ρ = 0.295, p = 0.004, respectively). We hypothesize that the reduced antioxidant potential of the diet might be related to a reduced variety of the diet in children with food allergies. Our study suggests that the diet of children with food allergies has a lower antioxidant potential (expressed as ORAC value) compared to the diet of healthy children, regardless of the allergenic food excluded from the diet. This issue should be further investigated in prospective, powered studies.

Long-Term Supplementation of Canthaxanthin Does Not Inhibit Gastric Epithelial Cell Proliferation in Helicobacter mustelae-Infected Ferrets

The effect of canthaxanthin (CX), a non-provitamin A carotenoid, on gastric epithelial proliferation was studied in ferrets colonized with Helicobacter mustelae, which causes a chronic gastritis and an increased gastric epithelial cell proliferation. Seven spayed female ferrets were dosed by gavage with CX beadlets (50 mg/kg body wt, 5 d/wk) over 2 y, whereas seven control animals were given placebo beadlets. At the end of the 2-y-period, ferrets were killed, and gastric tissues were obtained from the antrum and body regions. A cell-proliferating biomarker, proliferating cell nuclear antigen (PCNA), was assayed by immunohistochemistry. The PCNA positivity was measured by a computer-based image analysis system. Serum concentrations of carotenoids, retinoids and tocopherols were analyzed by HPLC. Serum antioxidant status was measured by the oxygen radical absorbance capacity (ORAC) assay. The PCNA positivity in both antrum and body regions was not significantly different between CX-fed ferrets and controls. Serum CX concentrations were significantly higher in CX-fed ferrets vs. controls (P<0.001), whereas levels of other carotenoids, retinoids and tocopherols were not significantly different. The ORAC values were not significantly different between groups. This study does not suggest inhibitory effects of CX on gastric epithelial cell proliferation in H. mustelae infected ferrets.

Exploiting Kinetic Features of ORAC Assay for Evaluation of Radical Scavenging Capacity.

The analysis and interpretation of data retrieved from Oxygen Radical Absorbance Capacity (ORAC) assays represent a challenging task. ORAC indexes originate from different mathematical approaches often lacking correct elucidation of kinetic features concerning radical scavenging reactions by antioxidant compounds. In this work, the expression of ORAC values as area under fluorescein (FL) decay curves (AUC) and lag time are critically compared. This multi-parametric analysis showed the extension of radical scavenging reactions beyond the lag time period for caffeic acid, gallic acid, reduced glutathione and quercetin, extending their antioxidant protection of FL. Ethanol delayed the reaction of both FL and antioxidant compounds with free radical species generated from 2,2'-azobis(2-amidinopropane) dihydrochloride thermolysis. Trolox equivalent values, commonly used to express ORAC values, were more affected by the differences in radical scavenging kinetics between the reference and the tested antioxidant compounds when calculated from AUC than from lag time. These findings stressed the importance of choosing calibrator compounds presenting ORAC kinetics similar to samples to prevent biased estimation of the antioxidant capacity. Additionally, the framework proposed here provides a sustainable analytical method for the evaluation of antioxidant capacity, with an AGREE score of 0.73.

In the Beginning Was the Bud: Phytochemicals from Olive (Olea europaea L.) Vegetative Buds and Their Biological Properties.

Even though Olea europaea L. is one of the most important and well-studied crops in the world, embryonic parts of the plants remain largely understudied. In this study, comprehensive phytochemical profiling of olive vegetative buds of two Croatian cultivars, Lastovka and Oblica, was performed with an analysis of essential oils and methanol extracts as well as biological activities (antioxidant, antimicrobial, and cytotoxic activities). A total of 113 different volatiles were identified in essential oils with hydrocarbons accounting for up to 60.30% and (Z)-3-heptadecene being the most abundant compound. Oleacein, oleuropein, and 3-hydroxytyrosol had the highest concentrations of all phenolics in the bud extracts. Other major compounds belong to the chemical classes of sugars, fatty acids, and triterpenoid acids. Antioxidant, antimicrobial, and cytotoxic activities were determined for both cultivars. Apart from antioxidant activity, essential oils had a weak overall biological effect. The extract from cultivar Lastovka showed much better antioxidant activity than both isolates with both methods (with an oxygen radical absorbance capacity value of 1835.42 μM TE/g and DPPH IC50 of 0.274 mg/mL), as well as antimicrobial activity with the best results against Listeria monocytogenes. The human breast adenocarcinoma MDA-MB-231 cell line showed the best response for cultivar Lastovka bud extract (IC50 = 150 μg/mL) among three human cancer cell lines tested. These results demonstrate great chemical and biological potential that is hidden in olive buds and the need to increase research in the area of embryonic parts of plants.

The effect of in vitro digestion on the chemical and antioxidant properties of Lycium barbarum polysaccharides

Although the antioxidant properties of Lycium barbarum polysaccharides (LBPs) are well known, little is known about how gastrointestinal digestion impacts their chemical and antioxidant properties. In this study, the molecular weight (Mw), total polysaccharide, protein and phenolic contents and the structural changes of LBPs were determined following digestion in vitro. During digestion, the decrease in the Mw of LBPs was observed. High Mw polysaccharides were found to be more stable compared to those with low Mw. There were 8 monosaccharides composed LBPs. The proportions of the monosaccharides increased except for the one of glucose after digestion. With the consuming of glucose, the percentages of glucuronic acid (GlcA) and galacturonic acid (GalA) significant multiplied from 1.18% to 1.94%, and 1.69%–4.25%, respectively. The total protein and phenolic contents were increased from 9.04% to 10.87% and 3.46%–3.89%, while the weight of total polysaccharides was decreased from 39.42% to 36.09%. Phenolics occur in their bound form, which conjugated to proteins or esterified to sugars. The changes of chemical features would take place in the gastric phase. The digestive product of LBPs (LBPs-IVD) exhibited a noticeably increase in antioxidant activities, as measured by oxygen radical absorbance capacity value, scavenging activity on ABTS+ free radical and reducing capacity. The increase in the bioactivity of LBPs-IVD is attributed to the high contents of phenolics and protein conjugated in LBPs and the high level of GalA and GlcA. Our results provide a new perspective for understanding the antioxidant properties of LBPs.