Phenolic compositions, and antioxidant performance of olive leaf and fruit (Olea europaea L.) extracts and their structure–activity relationships

Simultaneous High-Performance Recovery and Extended Acid-Catalyzed Hydrolysis of Oleuropein and Flavonoid Glycosides of Olive (Olea europaea) Leaves: Hydrothermal versus Ethanol Organosolv Treatment

Olive leaves (OLLs) are an exceptional bioresource of natural polyphenols with proven antioxidant activity, yet the applicability of OLL extracts is constrained by the relatively high polarity of the major polyphenols, which occur as glycosides. To overcome this limitation, OLLs were subjected to both hydrothermal and ethanol organosolv treatments, fostered by acid catalysis to solicit in parallel increased polyphenol recovery and polyphenol modification into simpler, lower-polarity substances. After an initial screening of natural organic acids, oxalic acid (OxAc) was found to be the highest-performing catalyst. The extraction behavior using OxAc-catalyzed hydrothermal and ethanol organosolv treatments was appraised using kinetics, while treatment optimization was accomplished by deploying response-surface methodology. The comparative assessment of the composition extracts produced under optimal conditions of residence time and temperature was performed with liquid chromatography-tandem mass spectrometry and revealed that OLLs treated with 50% ethanol/1.5% HCl suffered extensive oleuropein and flavone glycoside hydrolysis, affording almost 23.4 mg hydroxytyrosol and 2 mg luteolin per g dry weight. On the other hand, hydrothermal treatment with 5% OxAc provided 20.2 and 0.12 mg of hydroxytyrosol and luteolin, respectively. Apigenin was in all cases a minor extract constituent. The study presented herein demonstrated for the first time the usefulness of using a natural, food-grade organic acid to perform such a task, yet further investigation is needed to maximize the desired effect.

PhInd database - Polyphenol content in Agri-food by-products and trends in extraction technologies: A critical review

Sustainable Development Goal 12 and target 12.3 set by the United Nations aims to reduce"food waste" per capita global for 50% losses by 2030. Databases such as the PhInd could help us to achieve set goals via mapping the potential ways for valorization of polyphenols from the agri-food by-products and waste. Fruit by-products (73.2% of the PhInd entries) are the most studied sources of polyphenols and future studies might be more focused on vegetables. More than half (55.8%) of entries were evaluated polyphenols in samples created in laboratory. These samples could have significantly different composition from industrial samples. Solid-liquid extraction (53.5%) and solvents like water, ethanol and aqueous ethanol (51.5%) were the most often used for extraction of polyphenols. Green solvents as NADES (0.4%) are rarely used in studies and should be more explored.

Guide for Optimization of Olive Leaf Extraction and Silver Nanoparticles Biosynthesis as an Initial Step for Pilot Plant Design

This account presents the results of two successful optimization processes. First, a polyphenol-rich aqueous olive extract was obtained and then silver nanoparticles (AgNPs) synthesized with high efficiency. Selected parameters for both processes were optimized based on the procedure of the Box-Behnken multifactorial design. The independent variables in the extraction process were the biomass/water ratio, temperature, and time. For AgNPs synthesis, the independent variables were the volume of olive extract, temperature, and process duration. The relationship between the process parameters was visualized graphically by using the response surface methodology. A high fit of the experimental data with the predicted models was shown. The regression coefficients were high, 0.9936 for extraction and 0.9757 for AgNPs biosynthesis. The extraction efficiency under its optimal conditions was as follows: biomass/solvent ratio 0.016, temperature 80 °C for 80 min, and yield 160.67 [μg GAE (gallic acid equivalent)/mL]. The highest yield of AgNPs synthesis, equal to 1.955, was obtained when it was carried out for 50 min at 75 °C with the application of 11 mL of extract. Studies on the AgNPs suspension's stability depending on the extract amount were demonstrated. A physicochemical analysis using dynamic light scattering, transmission electron microscopy images, and Fourier transform infrared spectroscopy for AgNPs obtained under optimal conditions was shown. Finally, a pilot-scale biosynthesis of AgNPs was designed.

Antioxidant Extracts from Greek and Spanish Olive Leaves: Antimicrobial, Anticancer and Antiangiogenic Effects

Olea europaea L. is the most valuable species of the Olea type, and its products offer a wide range of therapeutical uses. The olive tree has been extensively studied for its nourishing qualities, and the "Mediterranean diet", which includes virgin olive oil as a key dietary component, is strongly associated with a reduced risk of cardiovascular disease and various malignancies. Olive leaves, a by-product in the olive harvesting process, are valued as a resource for developing novel phytomedicines. For this purpose, two ethanolic extracts obtained from Olivae folium from Spain (OFS) and Greece (OFG) were investigated. Our findings contribute to a wider characterization of olive leaves. Both extracts displayed important amounts of phenolic compounds and pentacyclic triterpenes, OFG having higher concentrations of both polyphenols, such as oleuropein and lutein, as well as triterpenes, such as oleanolic acid and maslinic acid. The antioxidant capacity is similar for the two extracts, albeit slightly higher for OFG, possibly due to metal polyphenol complexes with antioxidant activity. The extracts elicited an antimicrobial effect at higher doses, especially against Gram-positive bacteria, such as Streptococcus pyogenes. The extract with lower inorganic content and higher content of polyphenols and triterpenic acids induced a strong anti-radical capacity, a selective cytotoxic effect, as well as antimigratory potential on A375 melanoma cells and antiangiogenic potential on the CAM. No irritability and a good tolerability were noted after evaluating the extracts on the in vivo Hen's Egg Test-Chorioallantoic Membrane (HET-CAM). Therefore, the present data are suggestive for the possible use of the two types of olive leaf products as high-antioxidant extracts, potentially impacting the healthcare system through their use as antimicrobial agents and as anticancer and anti-invasion treatments for melanoma.

Anti-inflammatory effects of Olive (olea europaea L.) fruit extract in LPS-stimulated RAW264.7 cells via MAPK and NF-κB signal pathways

BACKGROUND

Olive is an evergreen tree of Oleaceae Olea with numerous bioactive components. While the anti-inflammatory properties of olive oil and the derivatives are well-documented, there remains a dearth of in-depth researches on the immunosuppressive effects of olive fruit water extract. This study aimed to elucidate the dose-effect relationship and underlying molecular mechanisms of olive fruit extract in mediating anti-inflammatory responses.

METHODS AND RESULTS

The impacts of olive fruit extract on the release of nitric oxide (NO), tumor necrosis factor (TNF-α), interleukins-6 (IL-6) and reactive oxygen species (ROS) were assessed in RAW264.7 cells induced by lipopolysaccharide (LPS). For deeper understanding, the expression of genes encoding inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), TNF-α and IL-6 was quantitatively tested. Additionally, the expression patterns of MAPK and NF-κB pathways were further observed to analyze the action mechanisms. Results suggested that olive fruit extract (200, 500, 1000 µg/mL) markedly exhibited a dose-dependent reduction in the generation of NO, TNF-α, IL-6 and ROS, as well as the expression of correlative genes studied. The activation of ERK, JNK, p38, IκB-α and p65 were all suppressed when p65 nuclear translocation was further restricted by olive fruit extract in NF-κB and MAPK signal pathways.

CONCLUSIONS

Olive fruit extract targeted imposing restrictions on the signal transduction of key proteins in NF-κB and MAPK pathways, and thereby lowered the level of inflammatory mediators, which put an enormous hindrance to inflammatory development. Accordingly, it is reasonable to consider olive fruit as a potent ingredient in immunomodulatory products.

Comprehensive Review of Olea europaea: A Holistic Exploration into Its Botanical Marvels, Phytochemical Riches, Therapeutic Potentials, and Safety Profile

Human health is now inextricably linked to lifestyle choices, which can either protect or predispose people to serious illnesses. The Mediterranean diet, characterized by the consumption of various medicinal plants and their byproducts, plays a significant role in protecting against ailments such as oxidative stress, cancer, and diabetes. To uncover the secrets of this natural treasure, this review seeks to consolidate diverse data concerning the pharmacology, toxicology, phytochemistry, and botany of Olea europaea L. (O. europaea). Its aim is to explore the potential therapeutic applications and propose avenues for future research. Through web literature searches (using Google Scholar, PubMed, Web of Science, and Scopus), all information currently available on O. europaea was acquired. Worldwide, ethnomedical usage of O. europaea has been reported, indicating its effectiveness in treating a range of illnesses. Phytochemical studies have identified a range of compounds, including flavanones, iridoids, secoiridoids, flavonoids, triterpenes, biophenols, benzoic acid derivatives, among others. These components exhibit diverse pharmacological activities both in vitro and in vivo, such as antidiabetic, antibacterial, antifungal, antioxidant, anticancer, and wound-healing properties. O. europaea serves as a valuable source of conventional medicine for treating various conditions. The findings from pharmacological and phytochemical investigations presented in this review enhance our understanding of its therapeutic potential and support its potential future use in modern medicine.

Valorization of edible films based on chitosan/hydroxyethyl cellulose/olive leaf extract and TiO2-NPs for preserving sour cream

Biodegradable edible films for sour cream packaging were developed based on chitosan (CS), hydroxyethyl cellulose (HEC), Olive leaf extract (OE), and titanium dioxide nanoparticles (TiO2-NPs). The prepared CS/HEC/TiO2-OE bionanocomposite films were evaluated for their antimicrobial and antioxidant activities as well as using FT-IR, mechanical, permeability, and contact angle. The effect of developed films on the lipid oxidation, microbiological load, and chemical properties of sour cream was investigated. The fabricated films had an antimicrobial impact against all tested strains. The film containing 8 % OE showed effective protection against fat oxidation, with a peroxide value of 3.21 meq O2/kg, a para-anisidine value 5.40, and free fatty acids of 0.82 mg KOH/kg. The films with OE 4 % and 8 % have a good effect on the microbiological load of sour cream for 90 days. These films did not influence the chemical composition of sour cream and therefore can be used in this sort of dairy product.

Preparation and structural characterization of epoxidized soybean oils-based pressure sensitive adhesive grafted with tea polyphenol palmitate

Vegetable oils-based pressure sensitive adhesives (PSAs) are green and sustainable but face unsatisfactory adhesion strengths and are prone to aging during storage and application due to the existence of residual double bonds and massive ester bonds. Nine common antioxidants (tea polyphenol palmitate (TPP), caffeic acid, ferulic acid, gallic acid, butylated hydroxytoluene, tertiary butylhydroquinone, butylated hydroxyanisole, propyl gallate, and tea polyphenols) were grafted into epoxidized soybean oils-PSA (ESO-PSA) system to enhance antiaging properties and adhesion strengths. Results showed ESO-PSAs grafted with caffeic acid, tertiary butylhydroquinone, butylated hydroxyanisole, propyl gallate, tea polyphenols, or TPP didn't occur failure with TPP having best performance. The optimal conditions were ESO reacted with 0.9 % TPP, 70 % rosin ester, and 7.0 % phosphoric acid at 50 °C for 5 min, under which peel strength and loop tack increased to 2.460 N/cm and 1.66 N, respectively, but peel strength residue reduced to 138.09 %, compared with control (0.407 N/cm, 0.43 N, and 1669.99 %). Differential scanning calorimetry and thermogravimetric results showed TPP grafting increased the glass transition temperature of ESO-PSA slightly but improved its thermal stability significantly. Fourier transform infrared spectroscopy and 1H nuclear magnetic resonance results showed TPP, phosphoric acid, and rosin ester all partially participated in the covalently crosslinking polymerization of ESO-PSAs and the rest existed in the network structures in the free form.

Antioxidant polysaccharide-enriched fractions obtained from olive leaves by ultrasound-assisted extraction with α-amylase inhibition, and antiproliferative activities

Polysaccharide-rich materials were extracted from the alcohol-insoluble solids of Olea europaea l. **leaves. Structural characteristics were determined by colorimetric techniques, FT-IR, GC-MS, SEC/MALS/VD/DRI, and NMR (1H,13C). The extract and its main macromolecular components were characterized to assess their ability toward antioxidant, α-amylase inhibition, and antiproliferative activities. Results revealed that the ultrasound olive leave extract comprises polysaccharides with uronic acid, galactose, arabinose, and glucose in molar percentages of 11.7%, 11.3%, 7.5%, and 4.9% respectively, constituting 41% of the total mass. In addition, polyphenols (21%) and proteins (9%) are associated with these polysaccharides. Further, the extract showed noticeable ORAC and free radical scavenging abilities, in addition to high in vitro antiproliferative activity against Caco-2 colon carcinoma cell lines. Similarly, the extract exhibited a strong, uncompetitive inhibition of α-amylase by 75% in the presence of the extract with 0.75 µg/mL of concentration. This research concludes that ultrasound extraction method can be used for the extraction of polysaccharide-polyphenol-protein complexes. These conjugates exhibit the potential for combined biological activities resulting from a synergistic effect of its compounds, making them promising ingredients for the development of functional food.

Olive Leaf Extracts from Three Italian Olive Cultivars Exposed to Drought Stress Differentially Protect Cells against Oxidative Stress

Olive leaves are an abundant by-product of olive oil production. Olive leaf extracts (OLEs) are rich in polyphenols, which can be used for health benefits. As polyphenols are the main antioxidant molecules in plants, plants typically increase their polyphenol content when exposed to drought stress. However, the phenolic profile of OLEs can vary in relation to the origin and variety of the plant material. In this work, olive leaf extracts from three different Italian olive cultivars (Giarraffa, Leccino, and Maurino) both exposed and not exposed to drought stress were studied in terms of antioxidant properties and profile, intestinal permeation, and protection against oxidative stress of human umbilical vein endothelial cells (HUVECs), since HUVECs are considered a model to study a wide range of diseases. OLEs from stressed Maurino and Giarraffa plants showed the highest increase in antioxidant capacity compared to controls. The phenolic profile of Maurino' was mainly increased by water deficit, with a large increase in the compounds oleuropein and luteolin-7-O-rutinoside. All tested extracts exposed to a water deficit protected HUVECs against oxidative stress by reducing ROS production, and this effect was more pronounced in OLEs from Giarraffa and Maurino exposed to drought stress compared to all other extracts. Finally, OLE from the stressed Giarraffa group showed a higher apparent permeability of antioxidant molecules than that of Maurino.

Alleviation of doxorubicin-induced cardiotoxicity in rat by mesenchymal stem cells and olive leaf extract via MAPK/ TNF-α pathway: Preclinical, experimental and bioinformatics enrichment study

BACKGROUND

Toxic cardiomyopathies were a potentially fatal adverse effect of anthracycline therapy.

AIM

This study was conducted to demonstrate the pathogenetic, morphologic, and toxicologic effects of doxorubicin on the heart and to investigate how the MAPK /TNF-α pathway can be modulated to improve doxorubicin-Induced cardiac lesions using bone marrow-derived mesenchymal stem cells (BM-MSCs) and olive leaf extract (OLE).

METHODS

During the study, 40 adult male rats were used. Ten were used to donate MSCs, and the other 30 were split into 5 equal groups: Group I was the negative control, Group II obtained oral OLE, Group III obtained an intraperitoneal cumulative dose of DOX (12 mg/kg) in 6 equal doses of 2 mg/kg every 48 h for 12 days, Group IV obtained intraperitoneal DOX and oral OLE at the same time, and Group V obtained intraperitoneal DOX and BM-MSCs through the tail vein at the same time for 12 days. Four weeks after their last dose of DOX, the rats were euthanized. By checking the bioinformatic databases, a molecularly targeted path was selected. Then the histological, immunohistochemistry, and gene expression of ERK, JNK, NF-κB, IL-6, and TNF-α were done.

RESULTS

Myocardial immunohistochemistry revealed severe fibrosis, cell degeneration, increased vimentin, and decreased CD-31 expression in the DOX-treated group, along with a marked shift in morphometric measurements, a disordered ultrastructure, and overexpression of inflammatory genes (ERK, NF-κB, IL-6, and TNF-α), oxidative stress markers, and cardiac biomarkers. Both groups IV and V displayed reduced cardiac fibrosis or inflammation, restoration of the microstructure and ultrastructure of the myocardium, downregulation of inflammatory genes, markers of oxidative stress, and cardiac biomarkers, a notable decline in vimentin, and an uptick in CD-31 expression. In contrast to group IV, group V showed a considerable beneficial effect.

CONCLUSION

Both OLE and BM-MSCs showed an ameliorating effect in rat models of DOX-induced cardiotoxicity, with BM-MSCs showing a greater influence than OLE.

Comparative Study of the Efficacy of EHO-85, a Hydrogel Containing Olive Tree (Olea europaea) Leaf Extract, in Skin Wound Healing

Olive tree (Olea europaea) leaf extract (OELE) has important antioxidant and anti-inflammatory properties, supporting its use in human clinical practice. We recently designed an amorphous hydrogel called EHO-85 (EHO indicates olive leaf extract in Spanish) containing OELE for skin ulcer treatments. Yet, its effectiveness has not been previously compared with other products used in routine clinical practice. This is necessary to evaluate its potential translation to the human clinic. Thus, in this study, the effect of EHO-85 on healing was evaluated in comparison with treatments containing Indian/Asiatic pennywort (Centella asiatica), hyaluronic acid, or dexpanthenol in a rat model. The speed of wound closure and histological parameters after seven and 14 days were analyzed. All treatments accelerated wound closure, but there were differences between them. Dexpanthenol after seven days produced the highest epithelialization and the lowest inflammation and vascularization. EHO-85 also promoted epithelialization and reduced vascularization. After 14 days, wounds treated with EHO-85 showed less inflammation and higher levels of collagen in the extracellular matrix. This indicates a higher degree of maturity in the regenerated tissue. In conclusion, the effect of EHO-85 on healing was equal to or superior to that of other treatments routinely used in human clinical practice. Therefore, these results, together with previous data on the effects of this hydrogel on ulcer healing in humans, indicate that EHO-85 is a suitable, low-cost, and efficient therapeutic option for wound healing.

Olea europaea L. leaf extract mitigates oxidative and histological damage in rat heart tissue exposed to combined noise and toluene: An experimental study

In many occupational settings, workers are frequently exposed to toluene and noise. However, the individual and combined effects of these exposures on the cardiovascular system have not been fully elucidated. Therefore, this study aimed to investigate the impact of simultaneous exposure to toluene and noise on the rat heart, while also evaluating the potential preventive effect of olive leaf extract (OLE). Forty-eight male Wistar rats were randomly assigned to eight groups (n = 6/group): control group (C), control group that received OLE (C + OLE), group exposed to noise (N), group exposed to noise and receiving OLE (N + OLE), group exposed to toluene (T), group exposed to toluene and receiving OLE (T + OLE), group co-exposed to noise and toluene (NT), and group co-exposed to noise and toluene and receiving OLE (NT + OLE). The rats in this study were subjected to simultaneous exposure to toluene and noise for a duration of six weeks, within a custom-built plexiglass chamber. Toluene was administered at a concentration of 300 ppm, while the noise level was set to 85 dB(A). The exposure chamber was equipped with a generation system, an exposure system, and a monitoring system, ensuring precise and accurate exposure conditions. After the six-week period, heart and blood samples were collected from the rats for subsequent analysis. Plasma levels of cholesterol (CHOL), triglycerides (TG), lactate dehydrogenase (LDH), and creatine kinase (CK) were measured, and histopathological investigation was conducted using HE staining. Additionally, superoxide dismutase (SOD) and catalase (CAT) activities, as well as malondialdehyde (MDA) levels in heart tissue were measured. Our results showed that simultaneous exposure to noise and toluene altered CHOL, TG, LDH, and CK levels, and also caused an increase in lipid peroxidation levels and superoxide dismutase activity, along with a decrease in catalase activity in the heart. A significant alteration in the myocardium was also observed. However, treatment with OLE was found to modulate these oxidative and histological changes, ultimately correcting the deleterious effects induced by the combined exposure to noise and toluene. Therefore, our study suggests that OLE could be a potential preventive measure for individuals exposed to toluene and noise in industrial settings.

Bioactive compounds and antioxidant activities of two industrial beers produced in Ivory Coast

Beer is a world-famous beverage that is universally popular. This might be as an effect of its sensory, nutritional, and therapeutic qualities. To date, in Côte d'Ivoire, no study has been carried out focused on the eventual health benefits of industrial beer consumption. In this study, the bioactive compounds (total phenols, total tannins, total flavonoids, total anthocyanins) and corresponding antioxidant activities of two industrial beers from maize and rice from two different breweries were investigated. Results showed that for all phenolic compounds, contents were not statistically different (P > 0.05). However, antioxidant activities (antiradical activity and ferric reducing antioxydant power) were more important in industrial beer from rice (57.57 ± 0.62% and 109.46 ± 0.39 μg/mL ascorbic acid irrespectively) than industrial beer from maize (39.19 ± 1.02% and 103.51 ± 0.62 μg/mL ascorbic acid). Total phenols, total flavonoids, and total anthocyanins were mostly responsible for the antioxidant activities (antiradical activity and ferric reducing antioxydant power) of two beers, with correlation coefficients ranging from r = 0.614 to r = 1. Globally, the two industrial beers were similars but differents from local traditional sorghum beer. Occurrence of phenolic compounds in beers coupled with antioxidant activities shows that beer consumption could have health benefits to condition that beers have a low-alcohol content and light-to-moderate consumption. However, further investigations aims health benefis aspect are necessary.

Changes in polyphenolic compounds and antioxidant activities of seed-used pumpkin during hydrothermal treatment

An environmentally friendly physical processing method, hydrothermal treatment (HT), was used to increase the content of specific compounds and antioxidant activities of seed-used pumpkin byproducts. The influence of hydrothermal temperature (80 °C-160 °C) and time (30-150 min) on changes in polyphenols and antioxidation was evaluated. The results revealed that the maximum free polyphenol content (140 °C for 120 min) was 3.96-fold higher than the untreated samples. Elevated temperature and long duration changed phenolic acid contents. For example, p-coumaric acid, rutin and chlorogenic acid exhibited a decreasing trend, and p-hydroxybenzoic acid, quercetin and cinnamic acid showed an increasing trend. Compared to controls, HT was significantly associated with increased antioxidant activities. To comprehensively reveal the influence of hydrothermal temperature and time on changes in polyphenolic content, back propagation artificial neural network (BP-ANN) models with accurate prediction ability were developed, and the results exhibited well-fitted and strong approximation ability (R² > 0.95 and RMSE < 2 %) and stability.

Biotransformation of white and black mustard grains through germination and enzymatic hydrolysis revealed important metabolites for antioxidant properties and cytotoxic activity against Caco-2 cells

Germination and enzymatic hydrolysis are biological processes with well-recognized positive effects on phenolic composition and antioxidant potential. This study aimed to apply those processes to white (Sinapsis alba) and black (Brassica nigra) mustard grains and to analyze the influences on the total phenolic content (TPC); phenolic and peptide profile determined by ultra-performance liquid chromatography-high resolution mass spectrometry (UPLC-HRMS); antioxidant potential (DPPH, ABTS, and FRAP assays); and cytotoxicity against Caco-2, a human colorectal adenocarcinoma cell line. Enzyme combinations for hydrolysis were different for each mustard grain, but for both species, enzymatic hydrolysis and germination showed a positive effect on antioxidant properties. From UPLC-HRMS analysis and molecular network studies, 14 peptides and 17 phenolic compounds were identified as metabolites released from mustard after processes application, which were strongly correlated with increased antioxidant activity. In addition, enzymatic hydrolysis applied in germinated mustard grains for both mustards increased the cytotoxic activity against Caco-2 human colorectal adenocarcinoma cell line.

Density Functional Theory Calculations and Molecular Docking Analyses of Flavonoids for Their Possible Application against the Acetylcholinesterase and Triose-Phosphate Isomerase Proteins of Rhipicephalus microplus

Ticks and tick-borne diseases constitute a substantial hazard to the livestock industry. The rising costs and lack of availability of synthetic chemical acaricides for farmers with limited resources, tick resistance to current acaricides, and residual issues in meat and milk consumed by humans further aggravate the situation. Developing innovative, eco-friendly tick management techniques, such as natural products and commodities, is vital. Similarly, searching for effective and feasible treatments for tick-borne diseases is essential. Flavonoids are a class of natural chemicals with multiple bioactivities, including the inhibition of enzymes. We selected eighty flavonoids having enzyme inhibitory, insecticide, and pesticide properties. Flavonoids' inhibitory effects on the acetylcholinesterase (AChE1) and triose-phosphate isomerase (TIM) proteins of Rhipicephalus microplus were examined utilizing a molecular docking approach. Our research demonstrated that flavonoids interact with the active areas of proteins. Seven flavonoids (methylenebisphloridzin, thearubigin, fortunellin, quercetagetin-7-O-(6-O-caffeoyl-β-d-glucopyranoside), quercetagetin-7-O-(6-O-p-coumaroyl-β-glucopyranoside), rutin, and kaempferol 3-neohesperidoside) were the most potent AChE1 inhibitors, while the other three flavonoids (quercetagetin-7-O-(6-O-caffeoyl-β-d-glucopyranoside), isorhamnetin, and liquiritin) were the potent inhibitors of TIM. These computationally-driven discoveries are beneficial and can be utilized in assessing drug bioavailability in both in vitro and in vivo settings. This knowledge can create new strategies for managing ticks and tick-borne diseases.

Screening and Evaluation of Active Compounds in Polyphenol Mixtures by a Novel AAPH Offline HPLC Method and Its Application

In this study, we developed a novel offline high-performance liquid chromatography (HPLC) method based on 2,2′-azobis(2-amidinopropane) dihydrochloride (AAPH) radicals for antioxidant screening in 20 polyphenolic compounds and used the Trolox equivalent antioxidant capacity assay to evaluate their antioxidant activity. Compared to the existing offline HPLC methods based on 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) and 2,2-diphenyl-1-picrylhydrazyl (DPPH), the offline HPLC method based on the AAPH radical is more sensitive. Additionally, we applied this method to Lepechinia meyenii (Walp.) Epling extract and screened out seven antioxidants, caffeic acid, hesperidin, rosmarinic acid, diosmin, methyl rosmarinate, diosmetin, and n-butyl rosmarinate, which are known antioxidants. Therefore, this study provides new insights into the screening of antioxidants in natural extracts.

Tomato Processing By-Products Valorisation through Ohmic Heating Approach

Tomato by-products from processing industries have a higher potential to be reused as a source of bioactive compounds. Reliable national data on tomato by-products and physicochemical characterisation that will inform and find effective planning on tomato waste management in Portugal is absent. To help obtain this knowledge, selected Portugal companies were recruited to obtain representative samples of by-products generation, and physicochemical composition was evaluated. Furthermore, an environmental-friendly method (the ohmic heating (OH) method, which allows the recovery of bioactive compounds in absence of hazardous reagents) was also used and compared with conventional methods to explore new safe value-added ingredients. Total antioxidant capacity and total and individual phenolic compounds were also evaluated by spectrophotometric and high-performance liquid chromatography (HPLC), respectively. Tomato processing by-products have revealed a higher potential since both collected samples from companies were rich in protein (between 16.3 to 19.4 g/100 g DW, with fibre content ranging from 57.8 to 59.0 g/100 g DW). In addition, these samples contain 17.0 g/100 g of fatty acids (mainly polyunsaturated, monounsaturated and saturated, such as linoleic, oleic, and palmitic acid, respectively). Also, they present mainly chlorogenic acid and rutin as phenolic compounds. After understanding its composition, the OH was applied to determine added-value solutions to tomato by-products. With extractions, two types of fractions were obtained, namely liquid fraction rich in phenols, free sugars, and carotenoids and a solid fraction rich in fibre bound to phenols and carotenoids. This treatment has been shown to have the ability to preserve carotenoids, such as lycopene relative to conventional methods. Nevertheless, new molecules were identified by LC-ESI-UHR-OqTOF-MS analysis, such as phene-di-hexane and N-acethyl-D-tryptophan. According to the results, the OH boosts the potential of tomato by-products and can be directly introduced into the process, contributing to the circular economy and zero by-products.

Accumulation of Antioxidative Phenolics and Carotenoids Using Thermal Processing in Different Stages of Momordica charantia Fruit

The bitter taste of M. charantia fruit limits its consumption, although the health benefits are well known. The thermal drying process is considered as an alternative method to reduce the bitterness. However, processing studies have rarely investigated physiochemical changes in fruit stages. The antioxidant activities and physiochemical properties of various fruit stages were investigated using different thermal treatments. The color of the thermally treated fruit varied depending on the temperature. When heat-treated for 3 days, the samples from the 30 °C and 90 °C treatments turned brown, while the color of the 60 °C sample did not change significantly. The antioxidant activities were increased in the thermally processed samples in a temperature-dependent manner, with an increase in phenolic compounds. In the 90 °C samples, the 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity presented a 6.8-fold higher level than that of nonthermal treatment in mature yellow fruit (S3), whereas the activity showed about a 3.1-fold higher level in immature green (S1) and mature green (S2) fruits. Regardless of the stages, the carotenoid content tended to decrease with increasing temperature. In terms of antioxidant activities, these results suggested that mature yellow fruit is better for consumption using thermal processing.

Comparative metabolic profiling of olive leaf extracts from twelve different cultivars collected in both fruiting and flowering seasons

Olea europaea is an economically significant crop native to Mediterranean countries. Its leaves exhibit several biological properties associated to their chemical composition. The aqueous ethanolic extracts of olive leaves from twelve different cultivars were analyzed by high performance liquid chromatography coupled to photodiode array and electrospray ionization mass spectrometry (HPLC/PDA/ESI-MS/MS). A total of 49 phytochemicals were identified in both positive and negative ionization modes. The identified compounds belonged to four classes of secondary metabolites including secoiridoids, flavonoids, pentacyclic triterpenoids and various phenolic compounds. Seasonal variation in chemical composition among the studied cultivars was apparent in autumn and spring. Secologanoside, oleuropein, hydroxy-oleuropein, demethyl oleuropein, gallocatechin, luteolin-O-hexoside, diosmetin, oleanolic acid and maslinic acid were detected in all cultivars in both seasons. Oleuropein-O-deoxyhexoside was tentatively identified for the first time in olive leaf extracts; detected only in the Spanish cultivar Picual (PIC) collected in spring. Also, dihydroxy-oxooleanenoic acid and hydroxy-oxooleanenoic acid, two bioactive pentacyclic triterpenes, were identified. Principle component analysis (PCA) showed good discrimination among the studied cultivars in terms of their botanical origin. This study is considered the first study for non-targeted metabolic profiling of different olive leaf cultivars cultivated in Egypt.

Nocellara Del Belice (Olea europaea L. Cultivar): Leaf Extract Concentrated in Phenolic Compounds and Its Anti-Inflammatory and Radical Scavenging Activity

Olea europaea L. is a plant belonging to the Oleaceae family, widely grown around the Mediterranean Basin and its leaves are a source of phenolic compounds with antioxidant and anti-inflammatory capacity. Among these, oleuropein and luteolin-7-O-glucoside represent two major polyphenolic compounds in olive-leaf extract. Herein, a polystyrene resin was used to recover the polyphenolic fraction from the acetone-water leaf extract from Nocellara del Belice cultivar, which showed the higher level of analysed bioactive compounds, compared to Carolea cultivar. The antioxidant activity of the extract concentrated in phenolic compounds (OLECp) was evaluated through a classical assay and electron paramagnetic resonance (EPR) for DPPH and hydroxyl radicals scavenging. Thus, the anti-inflammatory activity and the potential beneficial effects in reducing lipid accumulation in an in vitro model of NAFLD using McA-RH7777 cells exposed to oleic acid (OA) were evaluated. Nile Red and Oil Red O have been used to stain the lipid accumulation, while the inflammatory status was assessed by Cytokines Bioplex Assay. OLECp (TPC: 92.93 ± 9.35 mg GAE/g, TFC: 728.12 ± 16.04 mg RE/g; 1 g of extract contains 315.250 mg of oleuropein and 17.44 mg of luteolin-7-O-glucoside) exerted a good radical scavenging capability (IC₅₀: 2.30 ± 0.18 mg/mL) with a neutralizing power against DPPH and hydroxyl radicals, as confirmed by the decreased signal area of the EPR spectra. Moreover, OLECp at concentration of 25, 50 and 100 μg/mL counteracted the intracellular inflammatory status, as result of decreased intracellular lipid content. Our results highlighted the multiple properties and applications of an O. europaea extract concentrated in polyphenols, and the possibility to formulate novel nutraceuticals with antioxidant properties, destined to ameliorate human health.

Phytochemical and antioxidant screening of Moringa oleifera for its utilization in the management of hepatic injury

Introduction

Phytochemicals present in Moringa oleifera (M. oleifera) leaves have performed several physiological functions in human system such as anticarcinogenic, antidiabetic, antioxidant, immunomodulatory, hepatoprotective and antiatherogenic functions.

Methods

Phytochemical and antioxidant potential of M. oleifera leaves extracts were measured. Histopathology, biochemical analysis, and gene expression tests were performed on serum, blood, and liver in animal model.

Results and discussions

The toxic dose of N-acetyl-para-aminophenol (APAP) induced severe structural and functional changes in liver. Pre-treatment with M. oleifera ameliorated organ injury by normalizing the level of liver biomarkers and serum proteins. A low expression level of MAPK-8, TRAF-4, and TRAF-6 genes was observed in the M. oleifera treated group in comparison to positive control (hepatotoxic rats). M. oleifera leaves pretreatment amended APAP induced apoptosis and replenished hepatic cells. M. oleifera leaves extract as low-cost and sustainable treatment could be used in pharmaceutical industry for reducing hepatic degenerative changes in non-communicable diseases.

Major Phytochemical Compounds, In Vitro Antioxidant, Antibacterial, and Antifungal Activities of Six Aqueous and Organic Extracts of Crocus sativus L. Flower Waste

PURPOSE

After being considered as a neglected product, agricultural waste is nowadays considered of paramount importance. It has become a source of many chemical compounds with industrial, pharmaceutical, and food applications. This study aims to evaluate the primary phytochemical content, the antioxidant properties, and the antimicrobial activities of different extracts of saffron flower waste (SFE) against bacterial and fungal strains involved in diverse pathologies in southern Morocco.

METHODS

Total phenolic and flavonoid contents were determined. The antioxidant potentials were assessed by DPPH, FRAP, and β-carotene assays. The antimicrobial activity against four bacteria and four fungi was also evaluated. The findings in terms of the relationships between phytochemical content and all activities were depicted by PCA analyses.

RESULTS

SFEs contained large amounts of phenolic and flavonoid compounds that contribute to the significant antioxidant activities. Diethyl ether (DE), n-Butanol (n-B), and Ethyl acetate (EA) fractions respectively exhibited more DPPH scavenging capacity, FRAP reducing power, and β-carotene bleaching inhibition. DE and EA have a remarkable effect mainly against Staphylococcus aureus strain, compared to Listeria monocytogenes, Escherichia coli and Klebsiella pneumoniae. Both SFEs showed antifungal antagonism towards key fungi species involved in post-harvest mold and crop yield losses. Botrytis cinerea was more susceptible than Fusarium solani, Penicillium expansum, and Penicillium digitatum.

CONCLUSION

These results reveal new data about extracts obtained from SFE that could be a potential source of natural antioxidant and antimicrobial agents opening new possibilities for their applications in the food system as a natural preservative and a sustainable alternative to conventional ingredients.

Nitrogen addition modifies the relative gene expression level and accumulation of carbon-based bioactive substances in Cyclocarya paliurus

In China, lots of Cyclocarya paliurus plantations have been established for tea and functional food production on nitrogen (N)-limited land. The optimum N levels require for biosynthesis and accumulation of carbon-based bioactive substances vary among plant species. This study integrated field trial with hydroponic culture to assess impact of nitrogen addition on accumulation and relative gene expression level of carbon-based secondary metabolites in C. paliurus. N addition significantly influenced not only contents of polyphenols, flavonoids and triterpenoids and relative gene expression levels of their biosynthetic pathway in C. paliurus leaves but also leaf biomass production and the bioactive substance accumulations. An intermediate N addition induced the highest contents of polyphenols, flavonoids and triterpenoids in leaves, but the optimized accumulation of these bioactive substances in the leaves was the trade-off between their contents and leaf biomass production. Correlation analysis showed that related gene expression levels were closely correlated with contents of their leaf corresponding secondary metabolites. Compared with ratios of carbon/N (C/N) and carbon/phosphorus (C/P) in the soil, ratios of C/N and C/P in the leaves were more strongly related to the contents and accumulations of polyphenols, flavonoids and triterpenoids. To obtain higher yields of targeted phytochemicals, the threshold ratios of C/N and C/P in the leaves are recommended for N and P fertilization at similar sites. Overall, our findings would provide the theoretical basis and technical support for manipulating N fertilization in C. paliurus plantations to obtain higher accumulations of targeted bioactive substances.

Bone-Marrow-Derived Mesenchymal Stem Cells, Their Conditioned Media, and Olive Leaf Extract Protect against Cisplatin-Induced Toxicity by Alleviating Oxidative Stress, Inflammation, and Apoptosis in Rats

BACKGROUND

Hepatic and renal damage is a cisplatin (Cis)-induced deleterious effect that is a major limiting factor in clinical chemotherapy.

OBJECTIVES

The current study was designed to investigate the influence of pretreatment with olive leaf extract (OLE), bone-marrow-derived mesenchymal stem cells (BM-MSC), and their conditioned media (CM-MSC) against genotoxicity, nephrotoxicity, hepatotoxicity, and immunotoxicity induced by cisplatin in rats.

METHODS

The rats were randomly divided into six groups (six rats each) as follows: Control; OLE group, treated with OLE; Cis group, treated with a single intraperitoneal dose of Cis (7 mg/kg bw); Cis + OLE group, treated with OLE and cisplatin; Cis + CM-MSC group, treated with BM-MSC conditioned media and Cis; and Cis + MSC group, treated with BM-MSC in addition to Cis.

RESULTS

Cis resulted in a significant deterioration in hepatic and renal functions and histological structures. Furthermore, it increased inflammatory markers (TNF-α, IL-6, and IL-1β) and malondialdehyde (MDA) levels and decreased glutathione (GSH) content, total antioxidant capacity (TAC), catalase (CAT), and superoxide dismutase (SOD) activity in hepatic and renal tissues. Furthermore, apoptosis was evident in rat tissues. A significant increase in serum 8-hydroxy-2-deoxyguanosine (8-OH-dG), nitric oxide (NO) and lactate dehydrogenase (LDH), and a decrease in lysozyme activity were detected in Cis-treated rats. OLE, CM-MSC, and BM-MSC have significantly ameliorated Cis-induced deterioration in hepatic and renal structure and function and improved oxidative stress and inflammatory markers, with preference to BM-MSC. Moreover, apoptosis was significantly inhibited, evident from the decreased expression of Bax and caspase-3 genes and upregulation of Bcl-2 proteins in protective groups as compared to Cis group.

CONCLUSIONS

These findings indicate that BM-MSC, CM-MSC, and OLE have beneficial effects in ameliorating cisplatin-induced oxidative stress, inflammation, and apoptosis in the hepatotoxicity, nephrotoxicity, immunotoxicity, and genotoxicity in a rat model.

Extraction of Polyphenolic Antioxidants from Red Grape Pomace and Olive Leaves: Process Optimization Using a Tailor-Made Tertiary Deep Eutectic Solvent

In the framework of introducing green strategies for food processing, the industrial orientation has shifted towards the replacement of conventional petroleum-based solvents with alternative eco-friendly ones. On this basis, the objective of this study was to synthesize a novel, tertiary, food-grade deep eutectic solvent, composed of glycerol, citric acid, and L-proline (GL-CA-Pro), and to test it as a solvent for the extraction of polyphenols from agri-food waste biomass. After an initial screening on various common residual materials (apple peels, lemon peels, orange peels, red grape pomace, olive leaves), evidence emerged that indicated GL-CA-Pro was more effective than other DESs commonly used for polyphenol extraction. Furthermore, extracts from red grape pomace (RGP) and olive leaves (OLL) were shown to contain higher level of total polyphenols and increased antioxidant activity. Process optimization for those two materials with the response surface methodology revealed that the major difference pertained to the extraction time. In addition, for both materials, GL-CA-Pro was shown to provide higher total polyphenol yields (53.25 and 42.48 mg gallic acid equivalents per g of dry mass, respectively) compared to water and 60% aqueous ethanol. However, the chromatographic analyses for OLL suggested aqueous ethanol was a more suitable solvent for some principal polyphenolic constituents. The RGP extract produced with GL-CA-Pro exhibited significantly stronger antioxidant effects compared to the aqueous and hydroethanolic extracts, but the outcome for the OLL extracts was diversified. It was concluded that GL-CA-Pro is a very efficient solvent for RGP polyphenols, but its efficiency regarding OLL was comparable to that of aqueous ethanol.

Variation in Bioactive Compounds and Antioxidant Activity of Rubus Fruits at Different Developmental Stages

Blackberry and raspberry have high nutritional, health value, and are popular with consumers for their unique flavors. To explore the relationships between nutrient accumulation, antioxidant substance contents in blackberry and raspberry fruits, and fruit growth and development, seven Rubus cultivars were selected, and contents of the main active substance were determined. "Clode Summit" had the highest soluble sugar and fructose contents, "Chester"-the highest total phenol content, and "Bristol'-the highest anthocyanin content. Generally, the contents of flavonoids and total phenols showed a downward trend with the development of fruit in seven Rubus cultivars, and the content of anthocyanins increased rapidly in the later stage of development. Pearson correlation analysis showed extremely significant correlation between antioxidant activity and the contents of vitamin E, total phenols, and flavonoids. Flavonoids were extremely significantly positively correlated with the content of total phenols, and the contents of flavonoids and anthocyanins in various cultivars were highly negatively correlated. Considering the different nutritional ingredients and active antioxidant substance contents, "Clode Summit", "Bristol", and "Chester" are recommended for raw consumption, processing, and medicinal purposes, respectively. These results provide a reference for comparing the main active substance contents in different Rubus cultivars and their changes across fruit development stages.

Production of hydroxytyrosol rich extract from Olea europaea leaf with enhanced biological activity using immobilized enzyme reactors

As olive leaves constitute the main by-product of the olive oil industry with important environmental and economic impact, there is an increasing demand for its valorization. In the present work, we report the development and application of immobilized enzyme batch bioreactors for the chemo-enzymatic treatment of an aqueous Olea europaea leaf extract rich in oleuropein to produce an extract enriched in hydroxytyrosol and other oleuropein hydrolysis products. To this end, a robust biocatalyst was developed through the immobilization of β-glucosidase on chitosan-coated magnetic beads which exhibited high hydrolytic stability after 240 h of incubation at 37 °C. The biocatalyst was successfully used in both a rotating bed-reactor and a stir-tank reactor for the modification of the olive leaf extract leading to high conversion yields of oleuropein (exceeding 90%), while an up to 2.5 times enrichment in hydroxytyrosol was achieved. Over 20 phenolic compounds (from different classes of phytochemicals such as flavonoids, secoiridoids, and their derivatives) were identified, in the extract before and after its modification through various chromatographic and spectroscopic techniques. Finally, the biological activity of both extracts was evaluated. Compared to the non-modified extract, the modified one demonstrated 20% higher antioxidant activity, seven-fold higher antibacterial activity, and enhanced cytotoxicity against leiomyosarcoma cells.

A review on benefits of quercetin in hyperuricemia and gouty arthritis

Hyperuricemia becomes a public health problem worldwide. It is not only a major risk factor for gout but also associated with the development of life-threatening diseases such as chronic kidney disease and cardiovascular diseases. Although there are several available therapeutic drugs, some serious adverse effects and contraindications are concerned. These drive the search for an alternative therapy that is effective and safe. Quercetin is of particular interesting since it has been reported numerous pharmacological activities, especially anti-hyperuricemia, antioxidant, anti-inflammation and amelioration of metabolic syndromes and cardiovascular diseases which are comorbidities of hyperuricemia and gout. In addition, quercetin has been widely used as a health supplement for many diseases however, the use for hyperuricemia and gout has not been indicated. Therefore, this review aims to gather and summarize published data regarding the efficacy in preclinical and clinical studies along with possible mechanism of action, and safety aspect of quercetin in order to support the use of quercetin as a dietary supplement for prevention and management of hyperuricemia and gouty arthritis and/or use as alternative or combination therapy to minimize the side effects of the conventional drugs.

Comparative Analysis between Synthetic Vitamin E and Natural Antioxidant Sources from Tomato, Carrot and Coriander in Diets for Market-Sized Dicentrarchus labrax

Synthetic vitamin E is commonly used in aquafeeds to prevent oxidative stress in fish and delay feed and flesh oxidation during storage, but consumers’ preferences tend towards natural antioxidant sources. The potential of vegetable antioxidants-rich coproducts, dried tomato (TO), carrot (CA) and coriander (CO) was compared to that of synthetic vitamin E included in diets at either a regular (CTRL; 100 mg kg⁻¹) or reinforced dose (VITE; 500 mg kg⁻¹). Natural antioxidants were added at 2% to the CTRL. Mixes were then extruded and dried, generating five experimental diets that were fed to European sea bass juveniles (114 g) over 12 weeks. Vitamin E and carotenoid content of extruded diets showed signs of degradation. The experimental diets had very limited effects on fish growth or body composition, immunomodulatory response, muscle and liver antioxidant potential, organoleptic properties or consumer acceptance. Altogether, experimental findings suggest that neither a heightened inclusion dose of 500 mg kg⁻¹ of vitamin E, nor a 2% inclusion of natural antioxidants provided additional antioxidant protection, compared to fish fed diets including the regular dose of 100 mg kg⁻¹ of vitamin E.

Novel Clotrimazole and Vitis vinifera loaded chitosan nanoparticles: Antifungal and wound healing efficiencies

Chitosan integrated nanoparticles of clotrimazole and Egyptian Vitis vinifera juice extract was evaluated in order to maximize the antifungal activity and reduce the gross side effects. In the present study Egyptian Thompson Seedless Vitis vinifera and Clotrimazole (Cz) loaded chitosan nanoparticles (NCs/VJ/Cz) showed a promising antifungal effect with average inhibition zone diameters of 74 and 72 mm against Candida albicans and Aspergillus niger respectively. NCs/VJ /Cz was stable with significant drug entrapment efficiency reached 94.7%; PDI 0.24; zeta potential value + 31 and average size 35.4 nm diameter. Ex vivo and in vivo evaluation of skin retention, permeation and wound repair potentialities of NCs/VJ /Cz ointment was examined by experimental rats with wounded skin fungal infection. Data proved the ability of NCs/VJ /Cz to gradually release the drugs in a sustained manner with complete wound healing effect and tissue repair after 7 days administration. As a conclusion NCs/VJ /Cz ointment can be used as a novel anti-dermatophytic agent with high wound healing capacity.

Incorporation of phenolic-rich ingredients from integral valorization of Isabel grape improves the nutritional, functional and sensory characteristics of probiotic goat milk yogurt

This study elaborated different probiotic goat milk yogurt formulations with addition of a low-calorie Isabel "Precoce" grape preparation and flour from derived solid by-products. Physicochemical characteristics, probiotic counts, phenolic and protein/peptide molecular weight profile, antioxidant capacity (AC) and sensory acceptance of different yogurt formulations were evaluated. Yogurts with Isabel grape ingredients (IGI) had high nutritional value, distinct phenolic profile and high AC. High counts of probiotic Lactobacillus acidophilus La-05 were found in yogurts during storage. AC of yogurts with IGI increased during a simulated gastrointestinal digestion with breakdown of high molecular weight proteins and release of protein-bound phenolics. AC of yogurts with IGI should be linked to goat milk peptides and Isabel grape phenolics. Yogurts with IGI had enhanced sensory acceptance. Incorporation of Isabel grape preparation and derived by-product flour into probiotic goat milk yogurt resulted in an added-value product with multifunctional characteristics and improved sensory characteristics.

Innovative Extraction Technologies for Development of Functional Ingredients Based on Polyphenols from Olive Leaves

Olive tree (Olea europea L.) leaves represent around 10% of the total weight of olives arriving at any given mill, which are generally discarded, causing economic and environmental issues. However, these are rich sources of natural bioactive compounds (i.e., polyphenols), which have health-promoting potential. Thus, the valorization of olive leaves by recovering and reusing their components should be a must for food sustainability and circular economy. This review provides an insight into the principal polyphenols present in olive leaves, together with agronomic variables influencing their content. It also summarizes the recent advances in the application of novel extraction technologies that have shown promising extraction efficacy, reducing the volume of extraction solvent and saving time and cost. Moreover, potential industrial uses and international patents filed in the pharmaceutic, food, and cosmetic sectors are discussed.

Quality assessment of leaf extracts of 12 olive cultivars and impact of seasonal variation based on UV spectroscopy and phytochemcial content using multivariate analyses

INTRODUCTION

Recently, focus has been made on the health-oriented uses of olive leaves, a byproduct of olive production, as a potential source of antioxidants. Oleuropein is one of the phenolic components in olive leaves known for its high antioxidant value.

OBJECTIVE

The main aim of the current study was constructing a model for the quality assessment of olive leaves and their potential phytochemical content and hence biological value as well. The phytochemical variation in olive leaves in both flowering (spring) and fruiting seasons (autumn) was also investigated.

METHODS

In this study, the leaves of 12 different olive cultivars from different geographical origins growing in Egypt were assessed for their oleuropein content, total flavonoid (TF) content and total polyphenol (Pph) content in spring and autumn via ultraviolet (UV) spectroscopy and high-performance liquid chromatography (HPLC) coupled to multivariate data analyses. The antioxidant activity of olive leaf extracts was assessed using 2,2'-diphenyl-1-picrylhydrazyl (DPPH) assay.

RESULTS

Higher levels of oleuropein, TF and Pph content were found in spring with the highest oleuropein content in the Spanish cultivar; Manzanillo, followed by the Italian cultivar Coratina and the Egyptian Agizi Okasi (218.94, 151.58 and 122.18 mg/100 g of dried leaf extract, respectively). UV spectra was also measured and the collected data were coupled to multivariate analyses showing clustering of cultivars with common geographical origin.

CONCLUSION

Our findings emphasised the influence of collection time and type of cultivar on the chemical profile of olive leaves. The model presented herein, serves for the quality assessment of olive leaves based on their phytochemical profile.

Genotype–Environment Interactions for Tree Growth and Leaf Phytochemical Content of Cyclocarya paliurus (Batal.) Iljinskaja

Cyclocarya paliurus (Batal.) Iljinskaja, as a woody tree species, has various health-promoting phytochemicals and is commonly used in tea production in China. A field trial for C. paliurus was conducted at two typical sites to evaluate genotype × environmental interaction (GEI) effects and identify the stability and adaptability of 13 families. The genotype main effects and genotype × environment interaction effects (GGE) were used to analyze the GEI effects for tree height, diameter at breast height (DBH), and leaf flavonoid and triterpenoid contents. Two-way analysis of variance indicated that the tree growth and leaf phytochemical contents were mainly affected by genotype and GEI. Based on the results of GGE, the JH1 family had high mean values and high stability in total flavonoid and total triterpenoid accumulations, while the KM4 family exhibited high means and high stability in tree height and DBH growth, as well as high means and medium stability in total triterpenoid content. Pearson’s correlation analysis indicated that the annual mean DBH was significantly and positively correlated with leaf phytochemical content in C. paliurus when all data for the 13 families at the two sites were used. Our results suggest that JH1 should be mainly extended as a superior genotype for the production of flavonoids and triterpenoids in the leaves, while KM4 could be spread for timber production or leaf triterpenoid production. This study provides useful information on the selection of C. paliurus genotypes in target sites and cultivation strategies for establishing oriented plantations.

The Impact of Anthocyanins and Iridoids on Transcription Factors Crucial for Lipid and Cholesterol Homeostasis

Nutrition determines our health, both directly and indirectly. Consumed foods affect the functioning of individual organs as well as entire systems, e.g., the cardiovascular system. There are many different diets, but universal guidelines for proper nutrition are provided in the WHO healthy eating pyramid. According to the latest version, plant products should form the basis of our diet. Many groups of plant compounds with a beneficial effect on human health have been described. Such groups include anthocyanins and iridoids, for which it has been proven that their consumption may lead to, inter alia, antioxidant, cholesterol and lipid-lowering, anti-obesity and anti-diabetic effects. Transcription factors directly affect a number of parameters of cell functions and cellular metabolism. In the context of lipid and cholesterol metabolism, five particularly important transcription factors can be distinguished: liver X receptor (LXR), peroxisome proliferator-activated receptor-α (PPAR-α), peroxisome proliferator-activated receptor-γ (PPAR-γ), CCAAT/enhancer binding protein α (C/EBPα) and sterol regulatory element-binding protein 1c (SREBP-1c). Both anthocyanins and iridoids may alter the expression of these transcription factors. The aim of this review is to collect and systematize knowledge about the impact of anthocyanins and iridoids on transcription factors crucial for lipid and cholesterol homeostasis.

Are olive pomace powders a safe source of bioactives and nutrients?

BACKGROUND

The olive oil industry generates significant amounts of semi-solid wastes, namely olive pomace. Olive pomace is a by-product rich in high-value compounds (e.g. dietary fibre, unsaturated fatty acids, polyphenols) widely explored to obtain new food ingredients. However, conventional extraction methods frequently use organic solvents, while novel eco-friendly techniques have high operational costs. The development of powdered products without any extraction step has been proposed as a more feasible and sustainable approach.

RESULTS

The present study fractionated and valorized the liquid and pulp fraction of olive pomace obtaining two stable and safe powdered ingredients, namely a liquid-enriched powder (LOPP) and a pulp-enriched powder (POPP). These powders were characterized chemically, and their bioactivity was assessed. LOPP exhibited a significant amount of mannitol (141 g kg^-1 ), potassium (54 g kg^-1 ) and hydroxytyrosol derivatives (5 mg g^-1 ). POPP exhibited a high amount of dietary fibre (620 g kg^-1 ) associated with a significant amount of bound phenolics (7.41 mg GAE g^-1 fibre DW) with substantial antioxidant activity. POPP also contained an unsaturated fatty acid composition similar to that of olive oil (76% of total fatty acids) and showed potential as a reasonable source of protein (12%). Their functional properties (solubility, water-holding and oil-holding capacity), antioxidant capacity and antimicrobial activity were also assessed, and their biological safety was verified.

CONCLUSIONS

The development of olive pomace powders for application in the food industry could be a suitable strategy to add value to olive pomace and obtain safe multifunctional ingredients with higher health-promoting effects than dietary fibre and polyphenols. © 2020 Society of Chemical Industry.

Recent development in biological activities and safety concerns of perillaldehyde from perilla plants: A review

Monoterpene Perillaldehyde (PAE) is a major component of the essential oil extracted from perilla plants (Perilla frutescens), which has been used as a leafy vegetable and a medicinal agent. PAE has gained a lot of attention in recent years because of its antifungal and other microbial activities and, human health benefits. PAE has also been used as food additives, perfume ingredients, and traditional medicine concoctions. Biological analyses of PAE have revealed that it has good antioxidant activities and can serve as organic fruit and food preservative. Animal studies indicated potent anticancer, anti-depressant, and anti-inflammatory effects of PAE. Also, PAE is certified "generally recognized as safe" (GRAS) and not mutagenic. However, moderation during usage is advisable, as minor adverse effects are associated with a very high dosage. Despite the newly reported findings, its properties have not been thoroughly summarized and reviewed. Also, clinical trials and official large-scale field applications of PAE in the agricultural sectors are yet to be reported. In this review, updated PAE research progress was provided, focusing on its antifungal and other antimicrobial properties and the mechanisms behind it, phytochemical profile, pharmacological effects, and safety concerns.HighlightsIsolation and recovery techniques of PAE from perilla plants have been developed and improved in recent years.PAE is a potential anti-oxidant and antifungal agent that can be widely used in the food industry.PAE can be developed into drug ingredients for pharmaceutical industries due to its anti-inflammatory, anti-cancer and anti-depressant activities.PAE can be safely used in human when low and moderate dosage is used.

In Vitro Gastrointestinal Digestion Impact on the Bioaccessibility and Antioxidant Capacity of Bioactive Compounds from Tomato Flours Obtained after Conventional and Ohmic Heating Extraction

In times of pandemic and when sustainability is in vogue, the use of byproducts, such as fiber-rich tomato byproducts, can be an asset. There are still no studies on the impact of extraction methodologies and the gastrointestinal tract action on bioactive properties. Thus, this study used a solid fraction obtained after the conventional method (SFCONV) and a solid fraction after the ohmic method (SFOH) to analyze the effect of the gastrointestinal tract on bioactive compounds (BC) and bioactivities. Results showed that the SFOH presents higher total fiber than SFCONV samples, 62.47 ± 1.24–59.06 ± 0.67 g/100 g DW, respectively. Both flours present high amounts of resistant protein, representing between 11 and 16% of insoluble dietary fiber. Furthermore, concerning the total and bound phenolic compounds, the related antioxidant activity measured by 2,2′-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS) radical cation decolorization assay presented significantly higher values for SFCONV than SFOH samples (p < 0.05). The main phenolic compounds identified in the two flours were gallic acid, rutin, and p-coumaric acid, and carotenoids were lycopene, phytofluene, and lutein, all known as health promoters. Despite the higher initial values of SFCONV polyphenols and carotenoids, these BCs’ OH flours were more bioaccessible and presented more antioxidant capacity than SFCONV flours, throughout the simulated gastrointestinal tract. These results confirm the potential of ohmic heating to modify the bioaccessibility of tomato BC, enhancing their concentrations and improving their antioxidant capacity.

Protective effects of olive oil phenolics oleuropein and hydroxytyrosol against hydrogen peroxide-induced DNA damage in human peripheral lymphocytes

This study investigates antioxidant capacity and protective effects of phenolic compounds oleuropein (OLP) and hydroxytyrosol (HT), present in olive oil and olive leaves, against H2O2-induced DNA damage in human peripheral lymphocytes. Antioxidant potency was determined using the measurement of radical-scavenging activity (ABTS∙+ assay), ferric reducing power (FRAP assay) and cupric reducing antioxidant capacity (CUPRAC assay). Both substances were found to be potent antioxidant agents due to their free radical-scavenging activities. Antigenotoxic effects of oleuropein and hydroxytyrosol against H2O2-induced damage in human lymphocytes were evaluated in vitro by alkaline comet assay. At tested concentrations (1, 5, 10 µmol L-1), oleuropein and hydroxytyrosol did not induce a significant increase of primary DNA damage in comparison with the negative control. Pretreatment of human lymphocytes with each of the substances for 120 min produced a dose-dependent reduction of primary DNA damage in the tested cell type. Hydroxytyrosol showed a better protective effect against H2O2-induced DNA breaks than oleuropein which could be associated with their free radical-scavenging efficacy.

Heracleum moellendorffii root extracts exert immunostimulatory activity through TLR2/4-dependent MAPK activation in mouse macrophages, RAW264.7 cells

Heracleum moellendorffii (H. moellendorffii) is a family of Umbelliferae and has long been used for food and medicinal purposes. However, the immune-enhancing activity of H. moellendorffii has not been studied. Thus, we evaluated in vitro immune-enhancing activity of H. moellendorffii through macrophage activation using RAW264.7 cells. Heracleum moellendorffii Root extracts (HMR) increased the production of immunomodulators such as NO, iNOS, IL-1β, IL-6 IL-12, TNF-α, and MCP-1 and activated phagocytosis in RAW264.7 cells. Inhibition of TLR2 and TLR4 reduced the production of immunomodulators induced by HMR. Inhibition of MAPK signaling attenuated the production of immunomodulators induced by HMR, but inhibitions of NF-κB or PI3K/AKT signaling did not affect HMR-mediated production of immunomodulators. HMR activated MAPK signaling pathway, and activation of MAPK signaling pathways by HMR was reversed by TLR2 and TLR4 inhibition. Based on the results of this study, HMR is thought to activate macrophages through the production of immunomodulators and phagocytosis activation through TLR2/4-dependent MAPK signaling pathway. Therefore, it is thought that HMR has the potential to be used as an agent for enhancing immunity.

Optimization of ultrasound-assisted aqueous two phase extraction of polyphenols from olive leaves

In this study, polyphenols from olive leaves was extracted by ultrasound-assisted aqueous two phase extraction (UAATPE). Based on single factor experiment and response surface methodology (RSM), the optimum extraction conditions of polyphenols contained 29% (w/w) (NH₄)₂SO₄, 35% (w/w) ethanol, pH 6.7, and 45 °C. The maximum extraction yield of polyphenols and oleuropein content were 34.06 mg/g and 44.13 mg/L, respectively. Compared with ultrasound-assisted extraction (UAE) and aqueous two phase extraction (ATPE), the extraction yield of polyphenols by UAATPE was 9.48 and 61.19% higher, respectively. In addition, the extract of UAATPE had higher purity. The results of antioxidant activity showed that polyphenols extracted by UAATPE had stronger DPPH and hydroxyl radicals scavenging ability and reducing power. Therefore, UAATPE is an efficient method for extracting polyphenols from olive leaves.