ORAC Tests Research Articles

166 Helichrysum italicum essential oil prevents skin lipids peroxidation caused by pollution and UV

Skin is the first shield against external assaults. Chronic exposure to Ultraviolet (UV) and pollution causes oxidative stress, responsible for lipids, DNA and proteins damage which in turn generate inflammation, acne and premature skin aging. The aim of this study was to evaluate the antioxidant properties of Helichrysum italicum essential oil (HIEO). The value of 104 811.5 μmol Trolox equiv/100g. obtained in ORAC test indicated a strong ability of HIEO to absorb peroxide radical. It was also efficient in protecting liposomes from degradation by hydroxyl radical in the conjugated diene method (-73.6% degradation at 0.1%). Lipophilic vitamin E (Vit E), the main antioxidant of skin surface, is transported from blood through sebaceous glands. Its depletion is associated with increased sebum peroxidation. Using squalene as a simplified model of sebum, 0.1% and 1% HIEO better prevented squalene oxidation under ozone (O3: 19.7% and 32% protection) than Vit E at the same concentrations (18.6% and 26.9%). Under singlet oxygen (1O2) exposure, while HIEO and Vit E values were comparable at 0.1% (22% and 26.7% protection), only HIEO efficacy increased at higher concentration (42.1% at 1%). A cosmetic formula containing HIEO and Vit E showed even higher protection under O3 (29.9%) and 1O2 (59.1%) exposure suggesting a synergy between the two compounds. 51 volunteers living in urban area applied the formula twice a day onto the face for 2 months. Sebum on the forehead was collected on Day 0 (D0), D28 and D56. Between D0 and D28, squalene monoperoxide (SQOOH) decreased by 28%∗ while Vit E increased by 71%∗ (∗p<0.0001). At D56, these values tended to stabilize, suggesting that the skin antioxidant balance was restored. Taken together, these results suggest that Helichrysum italicum essential oil could protect skin from pollution and UV induced oxidative stress. Its radical scavenger properties seem complementary to that of Vit E. Their combination could better protect skin than increasing Vit E concentration alone.

Efecto del isoespintanol y el timol en la actividad antioxidante de semen equino diluido con fines de congelación

Una amplia variedad de antioxidantes evaluados en la congelación de semen equino no ha arrojado resultados satisfactorios en el mantenimiento de su calidad y fertilidad. El isoespintanol y el timol son moléculas de origen natural con una alta actividad antioxidante, lo que las hace potencialmente útiles para reducir el estrés oxidativo del semen durante la criopreservación. Este estudio tuvo como objetivo evaluar el efecto del isoespintanol y el timol en la actividad antioxidante total y enzimática de semen equino diluido con fines de congelación. El semen de cinco caballos criollos colombianos se diluyó en un medio de congelación, se dividió en tres alícuotas que se asignaron aleatoriamente a los tratamientos isoespintanol (40 μM), timol (50 μM) o control (sin antioxidante). Se evaluó la capacidad antioxidante total (TAC) por los ensayos ORAC y FRAP. La actividad de catalasa (CAT), superóxido dismutasa (SOD) y glutatión peroxidasa (GPx) se evaluaron mediante pruebas enzimáticas. La evaluación estadística se realizó mediante modelos mixtos, análisis de correlación y comparación de medias por la prueba de Tukey. Las actividades de SOD y GPx fueron menores para el isoespintanol (6,7 ± 2,2 U/ ml y 0,16 ± 0,02 U/ml), comparadas con el timol (6,9 ± 2,2 U/ml y 0,20 ± 0,02 U/ml) y el control (7,2 ± 2,2 U/ml y 0,22 ± 0,02 U/ml) (p &lt; 0,05). No hubo diferencias para la TAC o la CAT del semen (p &gt; 0,05). El isoespintanol reduce la actividad de SOD y GPx en el semen equino diluido con fines de congelación.

Integrated process for the production of natural extracts from black spruce bark

Black spruce bark is an underestimated by-product from Quebec wood industry containing important quantities of valuable chemicals. We are presenting here an integrated process leading to a simultaneous extraction of an essential oil, a hydrosol and a polyphenol enriched hot water extract while the residual bark remains available for heat generation due to its preserved calorific value. Two types of hydrodistillation were tested: steam distillation (SD) and water distillation (WD). Since no difference was found between the two processes neither in respect to the essential oil and hydrosol production nor in respect to their chemical compositions, the focus of the present research was on the hot water extracts obtained from the two processes. The drained extract from water distillation process (WD-DE) was obtained at high yield (21.6%), and was determined to have the phenol and proanthocyanidin contents (337mg GAE/g, 139mg CChE/g) in the same range as the control (extract from simple hot water extraction), along with the remarkable concentration of trans-resveratrol (627mg/100g dry extract). The results of DPPH radical and ORAC tests indicate that all studied extracts have antioxidant activities, especially the WD-DE. Higher heating values of the remaining bark after extractions were determined to be almost identical as those of the original bark (around 20MJ/kg), indicating that black spruce bark would still be available for combustion, otherwise its conventional use, after the extraction. The integrated process of black spruce bark extraction presented here represents a new approach to the complete valorization of residual bark from wood transformation.

P 239 - Effects of persimmon extract in 3T3-L1 cells

There is growing evidence that natural products are important in the relationship between nutrients and healthin humans. Currently, one of the biggest problems in the food industries is the waste management that is generated in food production. In the present work, we have obtained a persimmon extract (PE) rich in bioactive compounds from the industrial sub-product of natural persimmon juice. We present here the characterization of bioactive components of PE and document their effects in hypertrophic and insulin resistant adipocytes. High-performance liquid chromatography coupled to mass spectrometry (HPLC-ESI-MS) was used for detected and identified carotenoids such as α-carotene, β-carotene and β-criptoxantin and polyphenols such as quercetin, procyanidin, hesperidin/neohesperidin, among others. To determine the properties of the PE, the antioxidant status was measured by the TEAC, FOLIN, FRAP and ORAC tests, showing a strong antioxidant activity. The intracellular ROS generation and triglyceride accumulation was measured by sensitive fluorescent probes in a hypertrophied adipocyte model. The results show that the PE exhibited an effective dose-dependent decrease of intracellular ROS generation as well as triglyceride accumulation in hypertrophic adipocytes. Therefore, PE extract can be used for preventive purposes against oxidative stress and obesity.

Protective effects of lichen metabolites evernic and usnic acids against redox impairment-mediated cytotoxicity in central nervous system-like cells

Lichens species produce unique secondary metabolites that attract increasing pharmacological interest, including their redox modulatory activities. Current work evaluated for the first time the in vitro cytoprotective properties, based on the antioxidant activities, of the Parmeliaceae lichens Evernia prunastri and Usnea ghattensis and the mechanism of action of their major phenolic constituents: the evernic and usnic acids, respectively. In two models of central nervous system-like cells (U373-MG and SH-SY5Y cell lines), exogenous H2O2 induced oxidative stress-mediated cytotoxicity. We first assessed their radical scavenging capacities (ORAC and DPPH tests) and the phenolic content of the extracts. At the optimal concentrations, pretreatments with evernic acid displayed significant protection against H2O2-induced cytotoxic damage in both models. It reversed the alterations in oxidative stress markers (including ROS generation, glutathione system and lipid peroxidation levels) and cellular apoptosis (caspase-3 activity). Such effects were in part mediated by a notable enhancement of the expression of intracellular phase-II antioxidant enzymes; a plausible involvement of the Nrf2 cytoprotective pathway is suggested. Usnic acid exerted similar effects, to some extent more moderate. Results suggest that lichen polyketides evernic and usnic acids merit further research as promising antioxidant candidates in the therapy of oxidative stress-related diseases, including the neurodegenerative disorders.

Aronia dietary drinks fortified with selected herbal extracts preserved by thermal pasteurization and high pressure carbon dioxide

The aim of this study was to design innovative aronia-herbal drinks, with a high content (80%) of fruit juice and high antioxidant capacity. Drinks contained cloudy aronia (chokeberry, Aronia melanocarpa) juice and extracts of cistus (Cistus incanus), green tea (Camellia sinensis) and nettle (Urtica dioica). Drinks were prepared in two lines: traditional with sucrose and a dietary version of 30% lower energy value with stevia extracts. Drinks were preserved using high pressure carbon dioxide (HPCD) and by thermal pasteurization (TP). Antioxidant capacity (AC) was assayed using ORAC, ABTS and DPPH tests, also the total content of polyphenols (TCP) and anthocyanins (TCA) were determined. Addition of herbal extracts to drinks increased the AC up to the level of 100% juice. The AC measured with the ORAC method was 20% (traditional line) and 16% (dietary line) higher than the sum of the ACs of the individual components, indicating the synergistic effect of fruit and herbal components. The DPPH test also showed a 14% synergistic effect for sucrose sweetened drinks. HPCD treatment reduced TCA in drinks by ca. 2–3 times less compared to TP; sucrose had a significant protective effect.

Imidazopyranotacrines as Non-Hepatotoxic, Selective Acetylcholinesterase Inhibitors, and Antioxidant Agents for Alzheimer's Disease Therapy.

Herein we describe the synthesis and in vitro biological evaluation of thirteen new, racemic, diversely functionalized imidazo pyranotacrines as non-hepatotoxic, multipotent tacrine analogues. Among these compounds, 1-(5-amino-2-methyl-4-(1-methyl-1H-imidazol-2-yl)-6,7,8,9-tetrahydro-4H-pyrano[2,3-b]quinolin-3-yl)ethan-1-one (4) is non-hepatotoxic (cell viability assay on HepG2 cells), a selective but moderately potent EeAChE inhibitor (IC50 = 38.7 ± 1.7 μM), and a very potent antioxidant agent on the basis of the ORAC test (2.31 ± 0.29 μmol·Trolox/μmol compound).

Hydrolyzable Tannins from Sweet Chestnut Fractions Obtained by a Sustainable and Eco-friendly Industrial Process

Sweet Chestnut (Castanea sativa Mill.) wood extracts, rich in Hydrolyzable Tannins (HTs), are traditionally used in the tanning and textile industries, but recent studies suggest additional uses. The aim of this work is the HPLC-DAD-ESI-MS characterization of Sweet Chestnut aqueous extracts and fractions obtained through a membrane separation technology system without using other solvents, and the evaluation of their antioxidant and antiradical activities. Total tannins range between 2.7 and 138.4 mM; gallic acid ranges between 6% and 100%; castalagin and vescalagin range between 0% and 40%. Gallic Acid Equivalents, measured with the Folin-Ciocalteu test, range between 0.067 and 56.99 g/100 g extract weight; ORAC test results for the marketed fractions are 450.4 and 3050 µmol/g Trolox Equivalents/extract weight. EC₅₀ values, measured with the DPPH test, range between 0.444 and 2.399 µM. These results suggest a new ecofriendly and economically sustainable method for obtaining chestnut fractions with differentiated, stable and reproducible chemical compositions. Such fractions can be marketed for innovative uses in several sectors.

Assessment of Antioxidant Activity and Neuroprotective Capacity on PC12 Cell Line of Frankenia thymifolia and Related Phenolic LC-MS/MS Identification.

This work aimed to investigate the richness of a Tunisian xerohalophyte Frankenia thymifolia aerial and root parts on phenolics and to evaluate the antioxidant and neuroprotective properties of this medicinal species. After fractionation using increasing and different solvent polarities, results displayed five fractions, where ethyl acetate (EtOAc) shoot and root fractions possess considerable total phenolic contents (221 and 308 mg of GAE/g of E, resp.) related to their important antioxidant activities such as ORAC (918 and 713 mg of TE/g of E), DPPH (282 and 821 mg of TE/g), and ABTS (778 and 1320 mg of TE/g) tests. Then, the identification of the main compounds by HPLC-DAD-ESI-MS and neuroprotective property of the most active fraction EtOAc were assessed. A total of 14 molecules were identified, which have been described for the first time in F. thymifolia. The major compounds identified were pinoresinol and kaempferol glycoside in aerial parts and gallic acid and ellagitannin in roots. Neuroprotective capacity against β-amyloid (Aβ) peptide induced toxicity in PC12 cells of EtOAc fraction showed a significant protective activity at lower concentration (25 and 50 µM). The relevant antioxidant and neuroprotective activities of F. thymifolia EtOAc fraction corroborated their chemical compositions.

Antioxidant, cytoprotective, anti-inflammatory and anticancer activities of Pistacia lentiscus (Anacardiaceae) leaf and fruit extracts

IntroductionPistacia lentiscus (Anacardiaceae) is used in Algeria for the treatment of inflammation, burns and gastrointestinal complaints. The present work was designed to establish the rational for the medical use of P. lentiscus, especially to determine the antioxidant, anti-inflammatory, cytoprotective and anticancer activities of leaf and fruit extracts and their fractions. MethodsThe antioxidant activity was assessed using the ORAC test, and the cytoprotective effect on H2O2-induced oxidative stress was also investigated. Anti-inflammatory activity was examined by measuring the secretion of interleukin-1β by macrophages exposed to ATP or H2O2. The anticancer potential of the crude extracts against melanoma (B16F10) and mammary (EMT6) cell lines was equally evaluated. UPLC–MS analysis was carried out for compound identification. ResultsThe crude extracts of leaf and fruit exhibited strong antioxidant activity in the ORAC assay and showed significant cytoprotective effect with maximum protection at 100μg/mL increasing cell viability by 108.25±1.73 and 104.13±0.97%, respectively. Fractions obtained from fruit extracts were ineffective, while the hydro-alcoholic-eluted fraction 3 of leaf displayed a significant cytoprotective effect. Leaf extract (100μg/mL) showed significant anti-inflammatory activity, compared to acetylsalicylic acid (ASA). Moreover, leaf and fruit extracts inhibited the growth of B16F10 cells (IC50=56.40 and 58.04μg/mL, respectively). Spectral analysis allowed the identification of six flavonol glycosides and five phenolic acids. ConclusionResults obtained in this study indicate that P. lentiscus extracts exhibited antioxidant, anti-inflammatory and anticancer properties, in accordance with the traditional uses of the plant.

Design, synthesis and biological activity of a novel Rutin analogue with improved lipid soluble properties

Recent interest in flavonoids has increased greatly due to their biological and pharmacological activities. Flavonoids, consist of a large group of low molecular weight polyphenolic substances, naturally occurring in fruits, vegetables, tea, and wine, and are an integral part of the human diet.Rutin is a common dietary flavonoid that is widely consumed worldwide from plant-derived beverages and foods as traditional and folk medicine remedy as well. Rutin exhibit important pharmacological activities, including anti-oxidation, anti-inflammation, anti-diabetic, anti-adipogenic, neuroprotective and hormone therapy. Here, we present the synthesis, antimicrobial, antiproliferative and pro-apoptotic effect on human leukemic K562 cells of compound R2, a new semi-synthetic derivative of Rutin as compared to Rutin itself. The new derivative was also included in finished topical formulations to evaluate a potential application to the dermatology field in view of the antioxidant/antimicrobial/antiinflammatory properties. Stability studies were performed by HPLC; PCL assay and ORAC tests were used to determine the antioxidant activity. R2 presented an antioxidant activity very close to that of the parent Rutin while bearing much better lipophilic character. Regarding antiproliferative effects on the human K562 cell line, R2 was found to be more effective than parent Rutin. Preliminary experiments demonstrated that R2 inhibits NF-kB activity and promotes cellular apoptosis.

Synthesis of natural-like acylphloroglucinols with anti-proliferative, anti-oxidative and tube-formation inhibitory activity

Two series of natural and natural-like mono- and bicyclic acylphloroglucinols derived from secondary metabolites in the genus Hypericum (Hypericaceae) were synthesised and tested in vitro for anti-proliferative and tube-formation inhibitory activity in human microvascular endothelial cells (HMEC-1). In addition, their anti-oxidative activity was determined via an ORAC-assay. The first series of compounds (4a–e) consisted of geranylated monocyclic acylphloroglucinols with varying aliphatic acyl substitution patterns, which were subsequently cyclised to the corresponding 2-methyl-2-prenylchromane derivatives (5a and 5d). The second series involved compounds containing a 2,2-dimethylchromane skeleton with differing aromatic acyl substitution (6a–d and 7a–e). Compound 7a, (5,7-dihydroxy-2,2-dimethylchroman-6-yl)-(3,4-dihydroxyphenyl)methanone), showed the highest in vitro anti-proliferative activity with an IC50 of 0.88 ± 0.08 μM and a remarkable anti-oxidative activity of 2.8 ± 0.1 TE from the ORAC test. Interestingly, the high anti-proliferative activity of these acylphloroglucinols was not associated with tube-formation inhibition. Compounds (E)-1-(3-(3,7-dimethylocta-2,6-dien-1-yl)-2,4,6-trihydroxyphenyl)-2-methylbutan-1-one (4d) and (5,7-dihydroxy-2,2-dimethylchroman-6-yl)(3,4-dimethoxyphenyl)methanone (6a) exhibited moderate to weak anti-proliferative effects (IC50 11.0 ± 1 μM and 48.0 ± 4.3 μM, respectively) and inhibited the capillary-like tube formation of HMEC-1 in vitro, whereas 7a was inactive. The most active compound in the ORAC assay was 7c, which exhibited an anti-oxidative effect of 6.6 ± 1.0 TE. However, this compound showed only weak activity during the proliferation assay (IC50 53.8 ± 0.3) and did not inhibit tube-formation.

Amazonian palm Oenocarpus bataua (“patawa”): Chemical and biological antioxidant activity – Phytochemical composition

In French Guiana, “diversity” within the Palm family is obvious since more than 75 species have been identified. Oenocarpus bataua Mart., called “patawa” is well known for its culinary uses whereas literature on its phytochemical composition and biological properties remains poor. This work deals with determining the antioxidant activity of this palm fruit and its polyphenol composition; Euterpe oleracea (açai) used as a reference. It turned out that patawa had a stronger antioxidant activity than açai in TEAC and FRAP tests. A similar activity was observed by DPPH assay whereas in ORAC and KRL tests, that açai showed an antioxidant activity respectively 2.6 and 1.5 fold higher than patawa. Polyphenolic composition, determined by UPLC/MSn, would imply the presence of anthocyanins, condensed tannins, stilbenes and phenolic acids, well known for their biological activities. These results present patawa fruit as a new amazonian resource for cosmetics, food and pharmaceuticals purposes.

Protective effect of the omega-3 polyunsaturated fatty acids: Eicosapentaenoic acid/Docosahexaenoic acid 1:1 ratio on cardiovascular disease risk markers in rats

BackgroundHigh consumption of fish carries a lower risk of cardiovascular disease as a consequence of dietary omega-3 long chain polyunsaturated fatty acid (n-3 PUFA; especially EPA and DHA) content. A controversy exists about the component/s responsible of these beneficial effects and, in consequence, which is the best proportion between both fatty acids. We sought to determine, in healthy Wistar rats, the proportions of EPA and DHA that would induce beneficial effects on biomarkers of oxidative stress, and cardiovascular disease risk.MethodsFemale Wistar rats were fed for 13 weeks with 5 different dietary supplements of oils; 3 derived from fish (EPA/DHA ratios of 1:1, 2:1, 1:2) plus soybean and linseed as controls. The activities of major antioxidant enzymes (SOD, CAT, GPX, and GR) were determined in erythrocytes and liver, and the ORAC test was used to determine the antioxidant capacity in plasma. Also measured were: C reactive protein (CRP), endothelial dysfunction (sVCAM and sICAM), prothrombotic activity (PAI-1), lipid profile (triglycerides, cholesterol, HDLc, LDLc, Apo-A1, and Apo-B100), glycated haemoglobin and lipid peroxidation (LDL-ox and MDA values).ResultsAfter three months of nutritional intervention, we observed statistically significant differences in the ApoB100/ApoA1 ratio, glycated haemoglobin, VCAM-1, SOD and GPx in erythrocytes, ORAC values and LDL-ox. Supplementation with fish oil derived omega-3 PUFA increased VCAM-1, LDL-ox and plasma antioxidant capacity (ORAC). Conversely, the ApoB100/ApoA1 ratio and percentage glycated haemoglobin decreased.ConclusionsOur results showed that a diet of a 1:1 ratio of EPA/DHA improved many of the oxidative stress parameters (SOD and GPx in erythrocytes), plasma antioxidant capacity (ORAC) and cardiovascular risk factors (glycated haemoglobin) relative to the other diets.

Antioxidant Properties of High-Lutein Grain-Based Functional Foods in comparison with Ferulic Acid and Lutein

Dietary antioxidants could alleviate oxidative damage to cellular components via their ability to scavenge reactive oxygen species and other free radicals. In this regard wholegrain foods are recognized sources of dietary antioxidants and thus they are linked with health promotion and reduced risk of chronic diseases. In the current study high-lutein wholegrain bread, cookie and muffin products were assessed in terms of antioxidant properties based on their ability to scavenge peroxyl, ABTS and DPPH radicals and compared with ferulic acid and lutein, the primary antioxidants in the products. Aqueous methanol extract and bound diethyl ether/ethyl acetate extract followed alkaline hydrolysis were employed in the antioxidant measurement. Antioxidant capacity of the products was influenced by food product, type of extract (e.g. unbound versus bound) and antioxidant assay. In the ORAC test similar antioxidant capacities were obtained for unbound phenol extracts either from fortified or unfortified products, while significant differences were observed in bound phenol extracts. Significant differences were also found between unbound and bound phenol extracts in their ability to scavenge ABTS radical cation. In the DPPH assay lutein-fortified products had scavenging capacities significantly higher than that of the unfortified ones. In general, the bound phenolic extracts contribute significantly higher to the antioxidant capacity than the unbound phenol extracts. Only the DPPH test showed the contribution of lutein to the antioxidant capacity. At a lutein level of about 1.1-1.2 mg per serving (e.g. 30g) the products would boost the daily intake of lutein and antioxidants, as well as consumption of wholegrain foods.

LC–ESI-TOF–MS identification of bioactive secondary metabolites involved in the antioxidant, anti-inflammatory and anticancer activities of the edible halophyte Zygophyllum album Desf.

In this work, liquid chromatography coupled to electrospray time-of-flight mass spectrometry (LC–ESI-TOF–MS) has been applied to screen bioactive metabolites in shoot extract of the medicinal halophyte Zygophyllum album. Among 10 compounds identified (saponins, flavonoids and sterols) five were reported for the first time in Z. album. Furthermore, novel biological activities of hexane, dichloromethane and methanolic extracts were assessed. Results showed that methanolic extract exhibit the highest antioxidant activity using in vitro ORAC test and anti-inflammatory activity, inhibiting by 84.8% NO release in RAW264.7 macrophages. However, dichloromethane extract proved the utmost antioxidant activity in cell (WS1) based-assay (IC50=57μg/ml) and interesting anticancer capacity against human lung carcinoma (A-549) and colon adenocarcinoma (DLD-1) cells (IC50=37 and 48μg/ml, respectively). These findings can be attributed to the presence of triterpenes, flavonoids and sterols in Z. album, which are widely known as powerful antioxidants and used in various industrial fields.

Synthesis, Antioxidant and Antimicrobial Activity of a New Phloridzin Derivative for Dermo-Cosmetic Applications

The phenolic compound phloridzin (phloretin 2′-O-glucoside, variously named phlorizin, phlorrhizin, phlorhizin or phlorizoside) is a prominent member of the chemical class of dihydrochalcones, which are phenylpropanoids. Phloridzin is specifically found in apple and apple juice and known for its biological properties. In particular we were attracted by potential dermo-cosmetic applications. Here we report the synthesis, stability studies and antimicrobial activity of compound F2, a new semi-synthetic derivative of phloridzin. The new derivative was also included in finished formulations to evaluate its stability with a view to a potential topical use. Stability studies were performed by HPLC; PCL assay and ORAC tests were used to determine the antioxidant activity. F2 presented an antioxidant activity very close to that of the parent phloridzin, but, unlike the latter, was more stable in formulations. To further explore potential health claims, antifungal activity of phloridzin and its derivative F2 were determined; the results, however, were rather low; the highest value was 31,6% of inhibition reached by F2 on Microsporum canis at the highest dose.

A new acylated flavone glycoside with antioxidant and radical scavenging activities from Teucrium polium leaves

The antioxidant properties of six flavones from Teucrium polium L., one of them isolated for the first time, have been established through the determination of their abilities to inhibit free radicals using DPPH, ABTS radicals and ORAC test. The structure of the new metabolite has been elucidated by 1-D (1H, 13C and DEPT) and 2-D (COSY, TOCSY, HSQC, CIGAR) NMR experiments and by ESI Q-TOF HRMS analysis. Flavones 1–3 presented an efficacious activity towards the stable DPPH radical. Analogously, compounds 2 and 3 resulted significantly active also versus ABTS cation radical. On the basis of the comparable bioactivity of luteolin-based compounds, the presence of an ortho-dihydroxy substitution in the flavone B-ring is supposed to be the structural feature responsible for the antioxidant activity.

Antioxidant activity of phenolic fractions in olive mill wastewater

Olive mill wastewater (OMW) contains a substantial amount of valuable antioxidant phenols that can be recovered for industrial application as food additives and pharmaceuticals. The present study was aimed at extracting different phenolic OMW fractions, and determining their antioxidant potential. Five different OMW fractions were obtained using fractionation techniques, their antioxidant potential determined by DPPH, ORAC and a β-carotene bleaching test. The total phenol level ranged between 115 and 170 mg/l. The phenolic compounds present in individual fractions were identified using the HPLC-PAD method, where the main compounds were hydroxytyrosol, tyrosol, caffeic acid, vanillic acid, verbascoside, oleuropein, ferulic acid, and p-coumaric acid. The five OMW fractions showed different antioxidant levels depending on the test used. DPPH test showed that the fraction of alkyl aromatic alcohols (AAAs) was the best with EC(50) of 20 mg/l and the pure hydroxytyrosol with 2 mg/l. ORAC test showed that AAA and semi hydrolysed total phenol (s-TP) fractions were significantly better than Trolox when compared to 20 mg/l of Trolox.

Novel molecular combination deriving from natural aminoacids and polyphenols: Design, synthesis and free-radical scavenging activities

Following the recent output of scientific publications in the matter of synergic activity between different antioxidants, we have undertaken the present study with the aim to synthesize new molecules with radical-scavengers activity based on the conjugation of bioactive portions (i.e. phenols, cysteine, methionine or tyrosine), characterized by different structures and mechanisms of action, to promote the simultaneous quenching of different radical species in the site of the oxidative damage. In this context, derivatives of phenolic acid, aminoacids and dopamine have been also prepared. The newly synthesized compounds were evaluated in vitro applying specific and complementary antioxidant test such as DPPH assay and ORAC test. As emerged from the evaluation, prerequisites for the activity of the synthesized molecules were: i) the maintenance of at least two hydroxylic groups on the aromatic moiety of phenolic portion, ii) the presence of a spacer between the aromatic moiety and the carbonilic group.