Phenolic composition and in vitro antioxidant capacity of four commercial phytochemical products: Olive leaf extract (Olea europaea L.), lutein, sesamol and ellagic acid

Extraction Processes with Several Solvents on Total Bioactive Compounds in Different Organs of Three Medicinal Plants

The extraction of secondary metabolites by water, MeOH:water (8:2) containing NaF, methanol, ethanol and acetone (all of them diluted (7:3) in water)from the different parts (leaves, flowers, stems and roots) of Passiflora caerulea L., Physalis peruviana L. and Solanum muricatum Aiton via decoction and maceration methods was studied. The highest extraction yields were recorded by methanol for decoction and acetone for maceration. The total polyphenol content (TPC) obtained by decoction had the highest TPC contents, and MeOH containing NaF was the best solvent for the extraction of TPC. Maceration was suitable for flavonoid extractions, with ethanol and acetone being the best solvents. In general, the highest levels of TPC and flavonoids were obtained from Passiflora leaves regardless of the solvent or extraction method applied. Furthermore, the roots of Physalis and Solanum showed important levels of these compounds in consonance with the total antioxidant activity (TAA) evaluated in the different organs of the plant in the three species. In this study, the solvents and extraction methods applied were tools that determined significantly the level of extraction of bioactive compounds, showing a different impact on plant organs for each medicinal species studied.

Improvement of the Shelf-Life Status of Modified Atmosphere Packaged Camel Meat Using Nisin and Olea europaea Subsp. laperrinei Leaf Extract

The impact of combined biopreservation treatment with Olea europaea subsp. laperrinei leave extracts (laper.OLE) and nisin on the quality attributes of camel steaks packaged under high O₂ (80%) and CO₂ (20%) atmosphere was investigated during refrigerated (1 ± 1 °C) long-term storage. As measured by reversed phase HPLC/DAD analysis, oleuropein is the phenolic compound most present in the chemical composition of laper.OLE (63.03%). Camel steaks treated with laper.OLE had a lower concentration of thiobarbituric acid-reactive substances (TBA-RSs) in the course of 30 days of storage. Surface metmyoglobin (MetMb) increased at a reduced rate in laper.OLE-treated samples compared to control samples. Neither modified atmosphere packaging (MAP) nor biopreservation treatments significantly altered the tenderness of camel steaks, expressed in terms of Warner-Bratzler shear force (WBSF), as compared to control samples. After 30 days of storage, psychrotrophic bacteria and Pseudomonas spp. counts were significantly lower in camel steaks treated with a combination of laper.OLE and nisin than in untreated steaks. Moreover, samples treated with laper.OLE received higher scores on bitterness acceptability. In sum, the use of combined biopreservation methods could be a sustainable solution for the preservation and promotion of the quality characteristics of camel meat in arid regions.

Effects of Olive Leaf Extracts as Natural Preservative on Retailed Poultry Meat Quality

Poultry meat is commonly marketed at refrigerated temperatures (2-5 °C). The major concern for retailers and consumers is the quality and safety of refrigerated poultry meat. During the chilling period, poultry meat undergoes too many undesirable changes due to microbial growth that leads to spoilage and economic loss. Therefore, this study was conducted to assess the effects of olive leaf extracts (OLE) used at three concentrations (0.25, 0.5, and 1%) on the sensory attributes, as well as the chemical and microbiological quality of raw poultry meat stored at 4 ± 1 °C for 15 days. The results revealed that the OLE addition reduced microbial growth successfully, and maintained the chemical quality and sensory attributes of poultry meat. Moreover, OLE extended the shelf-life of the poultry meat that held under proper refrigeration conditions up to 15 days compared to the control group, that was completely spoiled by the sixth day of storage. This study concludes that OLE could be used both as a natural antioxidant and an antimicrobial preservative for chilled poultry meat held at refrigerated temperature.

Immobilization of novel inorganic nano-complexes onto MWCNT nanomaterials as a novel adsorbent and anti-inflammatory therapy in an induced model of rheumatoid arthritis

Novel supported inorganic metal nano-complexes of Ag(I) and Co(II) derived from 4-amino-N-(4-methylpyrimidin-2-yl) benzene sulfonamide (SulMer) were synthesized using olive leaf extract as a reducing agent with grinding and microwave methods. The prepared samples were denoted as Comp1-6. The surface morphologies of the synthesized nanomaterials were analyzed using C, H, N, S analysis, Fourier-transform infrared spectroscopy, UV- visible spectroscopy, proton and carbon nuclear magnetic resonance, scanning electron microscopy, transmission electron microscopy, thermogravimetric analysis, and x-ray powder diffraction (XRD) analysis. The data revealed that all the synthesized complexes exhibited a 1:1 metal-to-ligand ratio with a coordination number of 4 or 6. The mean particle size of the nanomaterial samples was 25-35 nm. The XRD patterns indicated a crystalline nature for the complexes. The supported inorganic metal nano-complexes displayed good activity in the adsorptive removal of Direct Red 81 (DR-81) from aqueous solutions. In addition, the effect of the supported metal nano-complexes on the immune system was studied as well as how these anti-inflammatory compounds could be used to treat many autoimmune diseases, most notably rheumatoid arthritis. An experimental model for arthritis can be induced using complete Freund's adjuvant. It was shown that the supported complex offers several advantages such stability, eco-friendliness, simple experimental conditions, short reaction times, and easy work- up.

Phytochemical Profile of Capsicum annuum L. cv Senise, Incorporation into Liposomes, and Evaluation of Cellular Antioxidant Activity

Overproduction of oxidants in the human body is responsible for oxidative stress, which is associated with several diseases. High intake of vegetables and fruits can reduce the risk of chronic diseases, as they are sources of bioactive compounds capable of contrasting the free radical effects involved in cancer, obesity, diabetes, and neurodegenerative and cardiovascular diseases. Capsicum annuum L. cv Senise is a sweet pepper that is grown in the Basilicata region (Italy). It is an important source of polyphenols, carotenoids, and capsinoids and can play a key role in human health. In this study, an ethanol extract was obtained from C. annuum dried peppers and the analysis of the phytochemical composition was performed by LC-ESI/LTQ Orbitrap/MS. The extract was incorporated into liposomes, which showed small size (~80 nm), good homogeneity, negative surface charge, and good stability in storage. The biological activity of the extract was evaluated in the human hepatoma (HepG2) cell line, used as model cells. The extract showed no cytotoxic activity and reduced the intracellular reactive oxygen species (ROS) level in stressed cells. The antioxidant activity was further improved when the extract was loaded into liposomes. Moreover, the extract promoted the expression of endogenous antioxidants, such as catalase, superoxide dismutase, and glutathione peroxidase through the Nrf-2 pathway evaluated by RT-PCR.

Valorization of olive mill leaves through ultrasound-assisted extraction

Olive leaves farmed from trees are valuable for the production of functional extracts. Nonetheless, olive leaves (containing thin branches), which are separated during olives cleaning in the mill, have received little attention. In this context, a multiple response optimization was performed to maximize at once the yield, total phenolic content, oleouropein and antioxidant activity obtained by ultrasound-assisted extraction of this low-cost byproduct. The optimum was achieved using the following operational parameters: solid-to-liquid ratio, 5.9%; ethanol concentration, 47%; extraction time, 50 min. This enabled to obtain an extract with both high level of oleuropein and antioxidant activity. Besides oleuropein, other minor phenolic compounds were characterized in the extract, which could contribute to the antioxidant activity as Pearson correlation suggested. After this extraction step, how the phenolic extraction affects the recovery/profile of other constituents was evaluated, looking for the integral valorization of this resource towards the zero-waste.

Dietary citrus pulp and grape pomace as potential natural preservatives for extending beef shelf life

The shelf-life of beef was compared from 7-months old Angus steers (281 ± 15.4 kg initial body weight) fed 150 g/kg DM dried citrus pulp (DCP) or grape pomace (DGP) for 90 days. The antioxidant activity, bacterial load, and lipid and protein oxidation were evaluated on the longissimus lumborum subjected to air-permeable packaging at days 1, 3, 5, 7 and 9 post-slaughter. Beef antioxidant activity was DGP > DCP > control (P ≤ 0.05). Beef from steers fed DGP or DCP had higher L* values (P ≤ 0.05) and fewer (P ≤ 0.05) coliform counts than steers fed the control diet. Beef antioxidant activity was DGP > DCP > control (P ≤ 0.05). Beef TBARS and carbonyl contents were DGP < DCP < control (P ≤ 0.05). Overall, antioxidant activity decreased (P ≤ 0.05), while bacterial loads, TBARS and carbonyl contents increased (P ≤ 0.05) during retail display for all diets. Current findings indicate that DGP could be a better natural preservative than DCP when included in beef cattle finishing diets.

The Anti-Aging Potential of Neohesperidin and Its Synergistic Effects with Other Citrus Flavonoids in Extending Chronological Lifespan of Saccharomyces Cerevisiae BY4742

The anti-aging activity of many plant flavonoids, as well as their mechanisms of action, have been explored in the current literature. However, the studies on the synergistic effects between the different flavonoid compounds were quite limited in previous reports. In this study, by using a high throughput assay, we tested the synergistic effects between different citrus flavonoids throughout the yeast's chronological lifespan (CLS). We studied the effect of four flavonoid compounds including naringin, hesperedin, hesperitin, neohesperidin, as well as their different combinations on the CLS of the yeast strain BY4742. Their ROS scavenging ability, in vitro antioxidant activity and the influence on the extracellular pH were also tested. The results showed that neohesperidin extended the yeast's CLS in a concentration-dependent manner. Especially, we found that neohesperidin showed great potential in extending CLS of budding yeast individually or synergistically with hesperetin. The neohesperidin exhibited the strongest function in decreasing the reactive oxygen species (ROS) accumulation in yeast. These findings clearly indicated that neohesperidin is potentially an anti-aging citrus flavonoid, and its synergistic effect with other flavonoids on yeast's CLS will be an interesting subject for future research of the anti-aging function of citrus fruits.

Chemical composition, antioxidant activities, in an allergic asthma model, of Olea europaea L. leaf extracts from Collo (Skikda, Algeria)

This study is an attempt to characterize the chemical composition and antioxidant activity of olive leaves variety (namely Bouricha variety) that is very widespread in the East of Algeria. The aqueous extract (AE) of leaves was initially analyzed for its phenolic profile. Using the liquid chromatography coupled to tandem mass spectrometry analysis, it was possible to identify the predominant components in the AE of the leaves. This extract was hydrolyzed with acid and gave hydroxytyrosol (HT). AE and HT were evaluated for their 1,1-diphenyl-2-picrylhydrazyl radical scavenging capacity, ferric reducing antioxidant power and total antioxidant activity by phosphomolybdenum method. The antioxidant and anti-asthmatic activities of these extracts were examined in a model of experimental asthma in Wistar rats. For measuring the intensity of the airway inflammation, oxidative stress parameters were analyzed in lungs and a histological study of this tissue was performed. The obtained results showed that the sensitization of the ovalbumin (OVA) group induced lung inflammation and severe lipid peroxidation (LPO) revealed by a significant increase in malondialdehyde (MDA) levels and a decrease in the non-enzymatic and enzymatic antioxidant systems. However, the administration of AE and HT extracts significantly improved the antioxidant state in asthma disease and provided evidence for the relation between phenolic compounds and the high antioxidant activity of olive leaves extracts, especially HT more than AE.

Glucose-mediated protein glycation: Contribution of methanolic extract of Ceratonia siliqua L. in protection and in vitro potential inhibition of acetylcholinesterase

Chronic hyperglycemia presents the major etiology of diabetes mellitus and related complications mainly Alzheimer's disease, via the protein glycation and toxic products generated. In the current study, we investigated the eventual protective effect of the methanolic extract of Ceratonia siliqua L. (CsME) against glucose-mediated glycation in serum bovine albumin. The multi-stage glycation markers, namely fructosamines and advanced glycation end products (AGEs) levels were monitored along with measurement of thiol groups; moreover, the in vitro acetylcholinesterase (AChE) inhibition potential was carried out. HPLC was also assessed. Rutin was the main phenolic compound found in CsME. CsME showed a good capacity to inhibit AGEs, fructosamines and protected thiol groups against glycation. CsME exhibited a great AChE inhibition activity. In the present study, CsME prevented glucose-induced protein glycation, it also exhibited a good inhibition of AChE, suggesting its DM complications such as memory troubles related to AD. PRACTICAL APPLICATIONS: Neurodegenerative disorders ranging from memory troubles to Alzheimer's disease present the most diabetes mellitus complications and mainly attributed to protein glycation process. Currently, there is a strong trend to search for efficient natural sources of glycation and acetylcholinesterase inhibitors to replace the synthetic ones, whose secondary effects were shown. The present article tries to justify scientifically the wide use of Ceratonia siliqua L. in Moroccan folk medicine, demonstrating that the methanolic extract of leaves from this species presents a promising source of new natural compounds inhibiting acetylcholinesterase and acting in vitro against glycation generated compounds. Furthermore, for the first time, Rutin was the main phenolic compound found in this extract, these encouraging results should be coupled with further studies to integrate it in pharmaceutical formulations. As such, this paper should be of interest to a broad readership, including those interested in Biochemistry, Phytochemistry, pharmacology, and neurosciences.

Potential of Juniperus communis L as a nutraceutical in human and veterinary medicine

Plants have been used for thousands of years as medicine for treating variety of diseases and medical complaints by most of the civilizations. Juniperus communis L. is an evergreen aromatic shrub with high therapeutic potential for the treatment of diseases in human and animals. The plant is rich in aromatic oils, invert sugars, resins, catechin, organic acid, terpenic acids, leucoanthocyanidin, alkaloids, flavonoids, tannins, gums, lignins, wax, etc. Juniper berries or extract of the plant has traditionally been used as diuretic, anti-arthritis, anti-diabetes, antiseptic as well as for the treatment of gastrointestinal and autoimmune disorders. The essential oil and extracts of juniper have been experimentally documented to have antioxidant, antibacterial, antiviral and antifungal activities. Recent studies have also found anti-inflammatory, cytotoxic, hypoglycemic and hypolipidemic effects of berries in experimental models. Further, the essential oil incorporation retarded lipid peroxidation in preserved meat due to its high antioxidant effect which not only improved meat product quality but also improved shelf life of the product. Thus natural antioxidant such as juniper can be used in place synthetic antioxidant for the preservation and improving self-life of meat products. New well designed clinical trials in human and animals using well-characterized J. communis extract or oil need to be conducted so that additional information is generated which can support the use of this natural product as a nutraceutical.

Continuous Bioconversion of Oleuropein from Olive Leaf Extract to Produce the Bioactive Product Hydroxytyrosol Using Carrier-Immobilized Enzyme

Feasibility and stability were evaluated of a continuous multi-batch process for converting oleuropein (OLE) from olive leaf extract to the bioactive product hydroxytyrosol (HT). Carrier beads made of three different materials (calcium alginate, chitosan with deacetylated α-chitin nanofibers (DEChN), or porous ceramic) were investigated for morphology, thermogravimetric, sorption, and viscoelastic properties. Enzymatic hydrolysis of OLE conducted in a packed bed bioreactor containing cellulase immobilized to carrier beads yielded OLE degradation rates of ~ 90% and an average HT yield of ~ 70% over 20 batches. Ultimately, inorganic porous ceramic beads were less costly and exhibited superior performance relative to organic carriers and thus were deemed most suitable for industrial-scale HT production. Systems utilizing enzyme immobilization within packed bed reactors hold promise for achieving efficient production of valuable bioproducts from discarded biomass materials.

Dietary supplementation of olive leaf extract increases haematological, serum biochemical parameters and immune related genes expression level in common carp (Cyprinus carpio) juveniles

The present study investigated the effects of dietary olive leaf (Olea europea L.) extract (OLE) on some blood parameters and immune (TNF-α, IL-1ß and IL-8) related genes in different tissues (head kidney, liver and spleen) and resistance of common carp, Cyprinus carpio to Edwardsiella tarda. Five diets were prepared for fed fish (mean body weight 15.90 ± 0.93 g) with different rates of OLE (0.0%, 0.1%, 0.25%, 0.50% and 1.0%). A control diet was prepared non-supplemented with OLE. Increased haematocrit ratio, serum myeloperoxidase activity, immune response gene levels (IL-1β in head kidney tissue and TNF-α in spleen tissue) and survival rate against E. tarda particularly in the 0.1% OLE treatment group. In conclusion, results of the present study show that feeding common carp with a diet containing 1 g/kg OLE over a period of 60 days might be adequate to improve fish immune parameters, and survival rate against E. tarda. Therefore, OLE can be used as a dietary additive to prevent E. tarda in common carp.

Extraction optimization, antioxidant activity, and tyrosinase inhibitory capacity of polyphenols from Lonicera japonica

The objective of this research was twofold: first, to optimize the extraction process of Lonicera japonica polyphenols using a response surface methodology, and second, to study the antioxidant activity and tyrosinase inhibitory capacity of the polyphenols of different purities. High-speed shearing homogenization extraction was used to extract the polyphenols from L. japonica. The antioxidant activity and the effect of polyphenols on tyrosinase activity were studied using free radical scavenging assay and the tyrosinase method, respectively. The optimal extraction conditions with an extraction yield of 6.96% for polyphenols were determined as follows: ethanol volume fraction 57%, shearing time 3.30 min, and solid-liquid ratio 1:58. Lonicera japonica polyphenols exhibited potent scavenging activity on 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2, 2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), and inhibitory capacity on tyrosinase. The results suggested that L. japonica polyphenols could be explored as a natural antioxidant and tyrosinase inhibitor.

Physico-Chemical, Microbiological and Sensory Evaluation of Ready-to-Use Vegetable Pâté Added with Olive Leaf Extract

The shelf-life extension implicates the reduction of food waste. Plant polyphenols can have a crucial role in the shelf-life extension of foods. Olive leaf extract (OLE) is rich in phenolic compounds such as oleuropein, which is well-known for its antioxidant properties. Physico-chemical, microbiological and sensory aspects of non-thermally stabilized olive-based pâté fortified with OLE at concentrations of 0.5 (EX0.5) and 1 mg kg⁻¹ (EX1) were investigated. These samples were compared with olive-based pâté fortified with the synthetic antioxidant BHT (butylated hydroxytoluene) and with a control sample (CTR) without antioxidants. No sensory defects were perceived in all samples, even if a more intense typical olive flavour was perceived in samples containing OLE compared to those containing BHT and CTR. This result was confirmed by significantly higher levels of 2-methylbutanal and 3-methylbutanal in samples containing OLE compared to CTR and BHT. Moreover, the main microbial groups registered a significant loss of 0.5–1 logarithmic cycles in samples containing OLE, especially in EX1. The results of the present study indicate the potentiality of using OLE as natural preservatives in non-thermally stabilized olive-based pâté, since some spoilage-related microbial groups were negatively affected by the addition of OLE at the highest concentration.

The antidiabetic and antioxidant properties of some phenolic phytochemicals: A review study

BACKGROUND

One class of phytochemicals are phenols with (OH) group bounded to aromatic hydrocarbon group. The aim of this study was to review the anti-diabetic and anti-oxidant properties of important phenols.

METHODS

This is a review study with ethic number (95s108) from AJUMS. About 450 articles (original, review,etc) been screened; 40 of them in the range of (1992-2017) were used due to their correlation to the study purpose. 28 of them were indexed by "Web of science (ISI)", 24 of them indexed by pubmed and also 29 of them were indexed by scopus data center.

FINDINGS

Phenols affect diabetes in different ways. CGA suppress hepatic gluconeogenesis through the inhibition of G6Pase and is also an insulin sensitizer that potentiates insulin action. Curcumin reduce insulin resistance so decrease AGE's products in diabetes mellitus. Hydroxytyrosol regulates the calcium channels which plays key role in insulin secretion. Resveratrol increase the stimulation of glucose uptake and insulin secretion. CGA has similar antioxidant activity as vitamin E and ellagic acid maybe is even more potent than vitamin E. curcumin inhibits lipid peroxidation and scavenge superoxide anion and hydroxyl radicals. The antioxidant activity of hydroxytyrosol protects pancreatic cells from damage and death. Treatment with resveratrol significantly decreases the level of glucosylated hemoglobin.

CONCLUSION

All these phytochemicals have potent antidiabetic and antioxidant effects in different ways beside their other effects like anti-inflammatory and anti-carcinogenic properties in ellagic acid, or like anti-angiogenic and apoptogenic activities in curcumin. So we suggest further studies in the field of diabetes and antioxidation.

Olive Leaves Extract from Algerian Oleaster (Olea europaea var. sylvestris) on Microbiological Safety and Shelf-life Stability of Raw Halal Minced Beef during Display

Oleaster (wild olive tree) by-products represent a renewable and low-cost source of biopolyphenols. Leaf extracts (sylv.OLE) of Algerian oleaster, locally called a'hachad (Olea europaea subsp. europaea var. sylvestris), were applied at 1 and 5% (v/w) to raw Halal minced beef (HMB) in order to test its safety and shelf-life prolongation during retail/display. The total phenolic compound content in the extract was 198.7 ± 3.6 mg gallic acid equivalent. Ten compounds were identified in the sylv.OLE by High Performance Liquid Chromatography/Diode Array Detector (HPLC/DAD), of which oleuropein was the most abundant (43.25%). Samples treated with 5% sylv.OLE had significantly higher antimicrobial and antioxidant effects than those treated with 1% extract (p < 0.05). The addition of sylv.OLE reduced psychrotrophic counts as well as the level of pathogens (Salmonella enterica ser. Enteritidis and Shiga toxin-producing Escherichia coli O157:H7). A thiobarbituric acid reactive substance (TBARS) value of 2.42 ± 0.11 was reached throughout six days of retail/display in control samples, while the addition of 5% sylv.OLE reduced TBARS value by 58% (p < 0.05). The presence of sylv.OLE at the tested concentrations did not negatively influence the overall acceptability and bitterness of HMB.

Investigation of phenolic compounds and antioxidant activity of leaves extracts from seventeen cultivars of Iranian olive (Olea europaea L.)

The leaves of seventeen cultivars of olive growing in the north of Iran were investigated for total phenol content and antioxidant activity. The identification and quantification of main phenolic compounds were performed by reverse phase high performance liquid chromatography with diode array detector. The cultivars Kalamon, Gordal, and Coratina contained the highest concentration of phenolic compounds (190.65 ± 0.03, 184.72 ± 0.001, and 155.91 ± 0.06 mg GAE/g extract, respectively). The maximum radical scavenging activities were found in Gordal, Coratina, and Kalamon extracts (IC₅₀ 20.66, 22.95, and 26.74 µg ml^-1, respectively). The extracts of Mishen, Fishomi, and Arbequina (1971.37 ± 0.007, 1794.57 ± 0.001, and 1760.57 ± 0.005 µmol Fe II/g dried extract, respectively) showed highest antioxidant activity in FRAP assay. The identification analysis demonstrated the present of vanillin, rutin, luteolin 7-O-glucoside, oleuropein, and quercetin. The highest oleuropein concentrations were detected in cultivars Mishen, Beleidi, Kalamon, and Roghani while it was not detected in cultivars Conservolea, Amigdalolia, Leccino, and Fishomi.

In vitro antioxidant activity of olive leaf extract (Olea europaea L.) and its protective effect on oxidative damage in human erythrocytes

AIMS

This study aimed to evaluate in vitro antioxidant capacity of olive leaf extract (OLE), Olea europaea L., and its protective effect on peroxyl radical-induced oxidative damage in human erythrocytes.

MAIN METHODS

The OLE was evaluated by the following assays: i) total phenolic and flavonoid content; ii) oleuropein content; iii) Ferric reducing antioxidant power (FRAP); iv) antioxidant activity against ABTS•+, DPPH• and reactive oxygen and nitrogen species: superoxide anion ( O 2 · - ), hypochlorous acid (HOCl) and nitric oxide (NO•) and v) protective effect on peroxyl radical-induced oxidative damages in human erythrocytes as hemolysis, thiobarbituric acid reactive substances (TBARS) formation and oxyhemoglobin oxidation.

KEY FINDINGS

Total phenolic and flavonoid contents were 131.7 ± 9.4 mg gallic acid equivalents/g dry weight (dw) and 19.4 ± 1.3 mg quercetin equivalents/g dw, respectively. Oleuropein content was 25.5 ± 5.2 mg/g dw. FRAP analysis was 281.8 ± 22.8 mg trolox equivalent/g dw and OLE inhibited ABTS•+ (50% effective concentration (EC50) = 16.1 ± 1.2 μg/mL) and DPPH• (EC50 = 13.8 ± 0.8 μg/mL). The extract demonstrated effective ability to scavenge O 2 · -  (EC50 = 52.6 ± 2.1 μg/mL), NO• (EC50 = 48.4 ± 6.8 μg/mL) and HOCl (EC50 = 714.1 ± 31.4 μg/mL). The extract inhibited peroxyl radical-induced hemolysis (EC50 = 11.5 ± 1.5 μg/mL), TBARS formation (EC50 = 38.0 ± 11.7 μg/mL) and hemoglobin oxidation (EC50 = 186.3 ± 29.7 μg/mL) in erythrocytes.

SIGNIFICANCE

OLE is an important source of natural antioxidants; it has effective antioxidant activity against different reactive species and protects human erythrocytes against oxidative damage.

Comparison between red wine and isolated trans-resveratrol on the prevention and regression of atherosclerosis in LDLr (-/-) mice

Moderate consumption of red wine has been widely associated with reduced cardiovascular risk, mainly due to its composition in phenolic compounds with antioxidant activity, such as resveratrol. The objective of this study was to compare the effect of red wine vs. trans-resveratrol consumption on the prevention and regression of atherosclerosis in LDLr ^(-/-) mice. This study consisted of two protocols: "Prevention" (PREV) and "Regression" (REGR). Both protocols included four groups: red wine (WINE), dealcoholized red wine (EXT), trans-resveratrol (RESV), and control (CONT). In PREV protocol, animals received a regular diet for 8 weeks and then switched to an atherogenic diet for the following 8 weeks, while the opposite was performed in REGR. Animals that received atherogenic diet after an initial period of standard diet (PREV) gained more body weight (39.25±2.30%) than the opposite (29.27±1.91%, P=.0013), suggesting an interaction between age and weight gain. Trans-resveratrol showed the highest hypocholesterolemic effect during PREV, reducing total cholesterol, LDL-C, VLDL-C and HDL-C. Supplementation with trans-resveratrol and dealcoholized red wine changed the fatty acids profile in the liver in both protocols, leading to an increase of MDA concentrations and SOD activity in the PREV protocol. In conclusion, supplementation with trans-resveratrol, red wine and the same wine without alcohol altered biomarkers of oxidative stress and lipidemia but had no effect on the prevention or regression of fatty streaks. These data suggest that cardiovascular protection associated with the "French Paradox" may be a result of synergistic effects between wine and the Mediterranean diet.

Ethnobotany of Anti-hypertensive Plants Used in Northern Pakistan

Hypertension is one of the most important factors responsible for cardiovascular ailments worldwide. It has been observed that herbal products and alternative herbal therapies played a significant role in decreasing hypertension. The aim of the current study is to provide significant ethnopharmacological information, both qualitative and quantitative on medicinal plants related to hypertension from Northern Pakistan. The documented data were quantitatively analyzed for the first time in this area. A total of 250 participants were interviewed through semi-structured discussions and questionnaires. Quantitative indices including FC (Frequency citation), FIV (Family importance value), RFC (Relative frequency of citation) and DCI (Disease Consensus index) were calculated. A total of 192 plant species, belonging to 77 families were reported to be used in treatment of hypertension in Northern Pakistan. The most dominant life form reported was herbs (54%), with decoction (72 reports) and leaves (55.1%) were commonly utilized plant part. Highest FIV was recorded in Lamiaceae (327 FIV). RFC ranged from 0.08 to 1.08% while DCI varied from 0.233 to 0.000. In this study original data was compared with thirty one previous national and international published papers from neighboring region to compare the medicinal uses and obtain some novel plant species. About 42% of the medicinal plant species were reported for the first time in treatment of hypertension in comparison to these 31 published papers. Different phytochemical activities of antihypertensive plants were also reported from literature. This research work documents the traditional knowledge of medicinal plants usage and provides baseline in designing clinical trials and pharmacological analysis for treatment of hypertension.

Enhanced yield of oleuropein from olive leaves using ultrasound-assisted extraction

The aim of this study was to optimize the extraction of oleuropein from olive leaves through a systematic study of the effects of different parameters of ultrasound-assisted extraction (USAE) on the oleuropein yield, in comparison with conventional maceration extraction. A range of operational parameters were investigated for both conventional maceration extraction and USAE: solvent type, olive leaf mass-to-solvent volume ratio, and extraction time and temperature. Oleuropein yield was determined using high-performance liquid chromatography, with total phenolics content also determined. The optimized conditions (water-ethanol, 30:70 [v/v]; leaf-to-solvent ratio, 1:5 [w/v]; 2 hr; 25°C) provided ~30% greater oleuropein extraction yield compared to conventional maceration extraction. The total phenolics content obtained using the optimized USAE conditions was greater than reported in other studies. USAE is shown to be an efficient alternative to conventional maceration extraction techniques, as not only can it offer increased oleuropein extraction yield, but it also shows a number of particular advantages, such as the possibility of lower volumes of solvent and lower extraction times, with the extraction carried out at lower temperatures.

Geographical Characterization of Tunisian Olive Tree Leaves (cv. Chemlali) Using HPLC-ESI-TOF and IT/MS Fingerprinting with Hierarchical Cluster Analysis

The olive plant has been extensively studied for its nutritional value, whereas its leaves have been specifically recognized as a processing by-product. Leaves are considered by-products of olive farming, representing a significant material arriving to the olive mill. They have been considered for centuries as an important herbal remedy in Mediterranean countries. Their beneficial properties are generally attributed to the presence of a range of phytochemicals such as secoiridoids, triterpenes, lignans, and flavonoids. With the aim to study the impact of geographical location on the phenolic compounds, Olea europaea leaves were handpicked from the Tunisian cultivar "Chemlali" from nine regions in the north, center, and south of Tunisia. The ground leaves were then extracted with methanol : water 80% (v/v) and analyzed by using high-performance liquid chromatography coupled to electrospray time of flight and ion trap mass spectrometry analyzers. A total of 38 compounds could be identified. Their contents showed significant variation among samples from different regions. Hierarchical cluster analysis was applied to highlight similarities in the phytochemical composition observed between the samples of different regions.

Optimization of Conditions for Extraction of Polyphenols and the Determination of the Impact of Cooking on Total Polyphenolic, Antioxidant, and Anticholinesterase Activities of Potato

In this work we optimized the cooking and extraction conditions for obtaining high yields of total polyphenols from potato and studied the effect of three domestic methods of cooking on total phenols, antioxidant activity, and anticholinesterase activities. The optimization of the experiment was carried out by the experimental designs. The extraction of the polyphenols was carried out by maceration and ultrasonication. Determination of the polyphenols was performed by using the Folin-Ciocalteau reagent method. The antioxidant activity was evaluated by three methods: 1,1-diphenyl-2-picryl-hydrazyl (DPPH), 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS), and CUPRAC(Cupric reducing antioxidant capacity), the anticholinesterase activity was evaluated by the method of Elmann. The optimum of total phenolic obtained was: 4.668 × 10⁴, 1.406 × 10⁴, 3357.009, 16,208.99 µg Gallic Acid Equivalent (GAE)/g of dry extract for crude potato, steamed potatoes, in boiling water, and by microwave, respectively. The three modes of cooking cause a decrease in the total polyphenol contents, antioxidant and anticholinesterase activities.

Olive (Olea europaea L.) Biophenols: A Nutriceutical against Oxidative Stress in SH-SY5Y Cells

Plant biophenols have been shown to be effective in the modulation of Alzheimer’s disease (AD) pathology resulting from free radical-induced oxidative stress and imbalance of the redox chemistry of transition metal ions (e.g., iron and copper). On the basis of earlier reported pharmacological activities, olive biophenols would also be expected to have anti-Alzheimer’s activity. In the present study, the antioxidant activity of individual olive biophenols (viz. caffeic acid, hydroxytyrosol, oleuropein, verbascoside, quercetin, rutin and luteolin) were evaluated using superoxide radical scavenging activity (SOR), hydrogen peroxide (H₂O₂) scavenging activity, and ferric reducing ability of plasma (FRAP) assays. The identification and antioxidant activities in four commercial olive extracts—Olive leaf extract^TM (OLE), Olive fruit extract^TM (OFE), Hydroxytyrosol Extreme^TM (HTE), and Olivenol plus^TM (OLP)—were evaluated using an on-line HPLC-ABTS^•+ assay, and HPLC-DAD-MS analysis. Oleuropein and hydroxytyrosol were the predominant biophenols in all the extracts. Among the single compounds examined, quercetin (EC₅₀: 93.97 μM) and verbascoside (EC₅₀: 0.66 mM) were the most potent SOR and H₂O₂ scavengers respectively. However, OLE and HTE were the highest SOR (EC₅₀: 1.89 μg/mL) and H₂O₂ (EC₅₀: 115.8 μg/mL) scavengers among the biophenol extracts. The neuroprotection of the biophenols was evaluated against H₂O₂-induced oxidative stress and copper (Cu)-induced toxicity in neuroblastoma (SH-SY5Y) cells. The highest neuroprotection values (98% and 92%) against H₂O₂-induced and Cu-induced toxicities were shown by the commercial extract HTE^TM. These were followed by the individual biophenols, caffeic acid (77% and 64%) and verbascoside (71% and 72%). Our results suggest that olive biophenols potentially serve as agents for the prevention of neurodegenerative diseases such as AD, and other neurodegenerative ailments that are caused by oxidative stress.

Enhancing colour and oxidative stabilities of reduced-nitrite turkey meat sausages during refrigerated storage using fucoxanthin purified from the Tunisian seaweed Cystoseira barbata

The present study investigated the angiotensin-I converting enzyme (ACE) inhibitory activity and the antioxidant properties, in vitro and in cured meat sausages containing reduced levels of sodium nitrite, of fucoxanthin extracted from the Tunisian brown seaweed Cystoseira barbata (CBFX). Results revealed that CBFX exhibited great scavenging activities against DPPH free radicals (EC50 = 136 μg/ml), peroxyl radicals in the linoleate-β-carotene system (EC50 = 43 μg/ml) and hydroxyl radicals generated by Fenton reaction (DNA nicking assay). A considerable ferric reducing potential was also recorded for CBFX (EC50 = 34 μg/ml). It is interesting to note that CBFX was found to modulate the ACE activity, which is the key enzyme involved in the blood pressure regulation, with an EC50 of 5 μg/ml. When fucoxanthin was supplemented, the concentration of sodium nitrite added to cured turkey meat sausages was reduced from 150 to 80 ppm, coupled with the enhancement of colour and oxidative stabilities. Thus, CBFX, with noticeable antioxidant and antihyertensive effects, could be used as a natural additive in functional foods to alleviate potential human health hazards caused by carcinogenic nitrosamines formation.

Olive leaf extract concentrated in hydroxytyrosol attenuates protein carbonylation and the formation of advanced glycation end products in a hepatic cell line (HepG2)

Glycation takes place both at the cellular level and at the extracellular matrix level and generates, consequently, advanced glycation end-products (AGEs) associated with chronic diseases and the aging process. Two olive leaf extracts concentrated in (i) oleuropein (OLE-A; 93.9 mg oleuropein g^-1) and (ii) hydroxytyrosol (OLE-B; 54.5 mg hydroxytyrosol g^-1) were evaluated according to their antiglycative and antioxidant capacity in vitro. OLE-B exerted the highest anti-AGE effect in different glycation models (IC₅₀: 0.25-0.29 mg mL^-1). OLE-B showed the highest antioxidant capacity and methylglyoxal-trapping capacity (IC₅₀ 0.16 mg mL^-1). OLE-B showed a significant inhibitory effect against protein carbonylation (21%) and generation of argpyrimidine (26%) in a hepatocyte cellular carbonyl stress model evoked by methylglyoxal (MGO). OLE-B was further fractionated by solid phase-extraction, and the protective effect against protein carbonylation was only exerted by the fraction containing hydroxytyrosol. However, hydroxytyrosol standard, at the same concentration in the extract, inhibited the protein carbonylation below 10% but not significantly. The results indicate that the antiglycative activity of OLE in cells could be due to a synergic effect of hydroxytyrosol and other minor compounds with similar polarity. The research of the antiglycative activity in vivo could confirm these promising results and to propose OLE as a natural anti-AGE agent.