Oxidation Study of Oleocanthal and Oleacein Induced by Oxone.

A selective Oxone-induced oxidation of oleocanthal and oleacein, the two main secoiridoids of olive oil, to their bis-oxidized products is described. This protocol is based on a Baeyer-Villiger mechanism and the concentration of Oxone in the final solution. The bis-oxidation of the aldehydic compounds could be extended for the synthesis of various semisynthetic analogs. The obtained acids exhibit strong antioxidant activity, being efficient free radical scavengers.

Extraction solvent selection for Cannabis sativa L. by efficient exploration of cannabinoid selectivity and phytochemical diversity.

INTRODUCTION: Cannabis sativa L. is attracting worldwide attention due to various health-promoting effects. Extraction solvent type is critical for the recovery of bioactive compounds from the plant, especially cannabinoids. However, the choice of solvent is varied and not adequately warranted elsewhere, causing confusion in involved fields. OBJECTIVE: The present work aimed to investigate the effect of extraction solvent on C. sativa (hemp) with regard to cannabinoid recovery and phytochemical profile of the extracts, considering most of the related solvents. METHODOLOGY: The majority of solvents reported for C. sativa (n = 14) were compared using a representative hemp pool. Quantitative results for major and minor cannabinoids were rapidly and reliably obtained using ultrahigh-performance liquid chromatography coupled with photodiode array detection (UPLC-PDA). In parallel, high-performance thin-layer chromatographic (HPTLC) fingerprinting was employed, involving less toxic mobile phase than in relevant reports. Various derivatisation schemes were applied for more comprehensive comparison of extracts. RESULTS: Differential selectivity towards cannabinoids was observed among solvents. MeOH was found particularly efficient for most cannabinoids, in addition to solvent systems such as n-Hex/EtOH 70:30 and ACN/EtOH 80:20, while EtOH was generally inferior. For tetrahydrocannabinol (THC)-type compounds, EtOAc and n-Hex/EtOAc 60:40 outperformed n-Hex, despite its use in the official EU method. Solvents that tend to extract more lipids or more polar compounds were revealed based on HPTLC results. CONCLUSION: Combining the observations from UPLC quantitation and HPTLC fingerprinting, this work allowed comprehensive evaluation of extraction solvents, in view of robust quality assessment and maximised utilisation of C. sativa.

Association of hydroxytyrosol enriched olive oil with vascular function in chronic coronary disease.

BACKGROUND: Hydroxytyrosol reduces low-density lipoprotein oxidation, contributing to prevention of atherosclerosis progression. METHODS: In a prospective, crossover, double-blind, placebo-controlled trial, 30 chronic coronary artery syndrome (CCAS) patients were randomized to 4 capsules/day, containing 412.5 mg olive oil with 2.5 mg hydroxytyrosol (OOHT) each one or placebo for 1 month and then were crossed over to the alternate treatment (placebo or OOHT). We measured (a) perfused boundary region (PBR) of the sublingual arterial microvessels (increased PBR indicates reduced glycocalyx thickness), (b) flow-mediated dilation (FMD), (c) Coronary Flow Reserve (CFR) and markers of LV diastolic function by Doppler echocardiography, (d) pulse wave velocity (PWV), and (e) oxidative stress, inflammatory biomarkers and blood lipids at baseline and after treatment. RESULTS: Treatment with OOHT improved PBR, FMD, CFR and PWV compared to baseline (1.8 ± .3 vs. 1.7 ± .4 µm, p = .040, 3.7 ± 2.1 vs. 6.5% ± 2.3%, p < .001, 2.3 ± .4 vs. 2.5 ± .4, p = .030 and 11.1 ± 1.8 vs. 11.8 ± 2.3 m/s, p = .002) while there was no effect after placebo (p = NS). No effect of OOHT treatment was observed on blood pressure. There was a parallel improvement of E' of the mitral annulus and deceleration time of the E wave of mitral inflow after OOHT (p < .05) but not after placebo. Compared to baseline, treatment with OOHT reduced malondialdehyde, a marker of lipid peroxidation, oxidized LDL, triglycerides, PCSK9 and CRP blood levels (p < .05) in contrast to placebo. CONCLUSIONS: Hydroxytyrosol-enriched olive oil may have beneficial effects on endothelial, arterial and LV diastolic function likely by reducing oxidative and inflammatory burden in CCAS, though further studies are needed to confirm this mechanism.

Oxidized Forms of Olive Oil Secoiridoids: Semisynthesis, Identification and Correlation with Quality Parameters.

Secoiridoids is the prominent chemical class of olive oil polar constituents and are characterized by significant biological properties. They are abundant in different chemical forms and relatively high concentrations compared to other components, while prone to oxidation due to their chemical motif. In recent years, oxidized derivatives of secoiridoids have been reported, either as natural constituents of olive oil or as components which are gradually formed in all stages of its production and storage. The mono-oxidized forms of oleocanthal and oleacein named as the respective acids have been recently isolated from olive oil and unambiguously structurally characterized. Other oxidized forms of elenolic acid or more complex secoiridoids, such as those of oleuropein and ligstroside aglycones are also sporadically mentioned in the literature. No further information is provided since they have not been isolated in pure form in order to be accurately identified. Most of the time, they are generally referred as oxidized forms of the parent compounds and commonly identified based on mass spectrometric data. In the current study, the semi-synthesis of the main oxidized olive oil secoiridoids, i.e., oleocanthalic acid, oleaceinic acid, EDA acid, carboxylic form of elenolic acid, carboxylic form of ligstroside aglycon, and carboxylic form of oleuropein aglycon is described starting from the corresponding aldehydic derivatives, using SeO2/H2O2 as oxidative agents. Furthermore, their presence in a number of Greek olive oils was investigated as well, as possible correlation thereof with quality parameters.

Exploring the Immunotherapeutic Potential of Oleocanthal against Murine Cutaneous Leishmaniasis.

Leishmaniasis is a major tropical disease with increasing global incidence. Due to limited therapeutic options with severe drawbacks, the discovery of alternative treatments based on natural bioactive compounds is important. In our previous studies we have pointed out the antileishmanial activities of olive tree-derived molecules. In this study, we aimed to investigate the in vitro and in vivo antileishmanial as well as the in vivo immunomodulatory effects of oleocanthal, a molecule that has recently gained increasing scientific attention. Pure oleocanthal was isolated from extra virgin olive oil through extraction and chromatography techniques. The in vitro antileishmanial effects of oleocanthal were examined with a resazurin-based assay, while its in vivo efficacy was evaluated in Leishmania major-infected BALB/c mice by determining footpad induration, parasite load in popliteal lymph nodes, histopathological outcome, antibody production, cytokine profile of stimulated splenocytes and immune gene expression, at three weeks after the termination of treatment. Oleocanthal demonstrated in vitro antileishmanial effect against both L. major promastigotes and intracellular amastigotes. This effect was further documented in vivo as demonstrated by the suppressed footpad thickness, the decreased parasite load and the inflammatory cell influx at the infection site. Oleocanthal treatment led to the dominance of a Th1-type immunity linked with resistance against the disease. This study establishes strong scientific evidence for olive tree-derived natural products as possible antileishmanial agents and provides an adding value to the scientific research of oleocanthal.

Direct In Vitro Comparison of the Anti-Leishmanial Activity of Different Olive Oil Total Polyphenolic Fractions and Assessment of Their Combined Effects with Miltefosine.

The bioactive compounds present in the edible products of the olive tree have been extensively studied and their favorable effects on various disease risk factors have been demonstrated. The aim of this study was to perform a comparative analysis of the anti-leishmanial effects of total phenolic fractions (TPFs) derived from extra virgin olive oil with different phenolic contents and diverse quantitative patterns. Moreover, the present study investigated their association with miltefosine, a standard anti-leishmanial drug, against both extracellular promastigotes and intracellular amastigotes of a viscerotropic and a dermotropic Leishmania strain. The chemical compositions of TPFs were determined by high performance liquid chromatography with diode array detection (HPLC-DAD). Analysis of parasite growth kinetics, reactive oxygen species production and apoptotic events were determined by microscopy and flow cytometry. Our results revealed that the presence of oleacein (OLEA) and oleocanthal (OLEO) secoiridoids enhances the anti-leishmanial effect of TPF. The association between TPFs and miltefosine was suggested as being additive in Leishmania infantum and Leishmania major promastigotes, and as antagonistic in intracellular amastigotes, as was evaluated with the modified isobologram method. The obtained data verified that TPFs are bioactive dietary extracts with a strong anti-leishmanial activity and highlighted that fractions that are richer in OLEA and OLEO phenolic compounds possess stronger inhibitory effects against parasites. This study may contribute to improving the therapeutic approaches against leishmaniasis.

Structure and organization of the secretion apparatus of the mastic tree (Pistacia lentiscus L.) and LC-HRMS analysis of leaf extracts.

MAIN CONCLUSION: The quantitative profile of the biochemicals secreted by summer and winter leaves, present noticeable differences and appear to be qualitatively different from the biochemical profile of the commercially valuable mastic. The anatomy of the root and the primary and secondary shoot as well as that of the summer and winter leaves of P. lentiscus was thoroughly investigated. The secreting network was tracked throughout the plant axis, from the root to the leaves, and the active secreting cells of the duct epithelium were localized, while the secondary metabolites produced within the cells of the summer and winter leaf tissues were identified histochemically. Numerous phytochemicals were identified in the leaf extracts with UHPLC-qTOF MS analysis. The analyzed extracts from summer and winter leaves displayed similar qualitative profile, although quantitative differences were evident, since, during the summer, the leaves tend to synthesize the more complex amongst the identified compounds. The phytochemical profile of the leaf extracts turns to be completely different compared to that of the valuable mastic harvested from the injured trunks. Many of the compounds common in mastic were not detected in the analyzed leaves samples. The numerous secreting ducts either fail to form a unified network, so composition of the secreted material varies in the different organs of the plant or they compose a continuous network, but the biochemical profile of the secreted material differs along the plant axis. Such a detailed investigation of the secretion network of the mastic tree may assist the improvement of the yield and promote the production of valuable phytochemicals through in vitro cultures.

Isolation of Volatile Compounds with Repellent Properties against Aedes albopictus (Diptera: Culicidae) Using CPC Technology.

The present work describes the use of Centrifugal Partition Chromatography (CPC) for the bio-guided isolation of repellent active volatile compounds from essential oils. Five essential oils (EOs) obtained from three Pinus and two Juniperus species were initially analyzed by gas chromatography-mass spectrometry (GC/MS) and evaluated for their repellent properties against Aedes albopictus. The essential oil from needles of P. pinea (PPI) presented the higher activity, showing 82.4% repellency at a dose of 0.2 µL/cm2. The above EO, together with the EO from the fruits of J. oxycedrus subsp. deltoides (JOX), were further analyzed by CPC using the biphasic system n-Heptane/ACN/BuOH in ratio 1.6/1.6/0.2 (v/v/v). The analysis of PPI essential oil resulted in the recovery of (-)-limonene, guaiol and simple mixtures of (-)-limonene/ß-pheladrene, while the fractionation of JOX EO led to the recovery of ß-myrcene, germacrene-D, and mixtures of α-pinene/ß-pinene (ratio 70/30) and α-pinene/germacrene D (ratio 65/45). All isolated compounds and recovered mixtures were tested for their repellent activity. From them, (-)-limonene, guaiol, germacrene-D as well the mixtures of (-)-limonene/ß-pheladrene presented significant repellent activity (>97% repellency) against Ae. albopictus. The present methodology could be a valuable tool in the effort to develop potent mosquito repellents which are environmentally friendly.

Hydroxytyrosol ameliorates metabolic, cardiovascular and liver changes in a rat model of diet-induced metabolic syndrome: Pharmacological and metabolism-based investigation.

Metabolic syndrome is a clustering of interrelated risk factors for cardiovascular disease and diabetes. The Mediterranean diet has been proposed as an important dietary pattern to confer cardioprotection by attenuating risk factors of metabolic syndrome. Hydroxytyrosol (HT) is present in olive fruit and oil, which are basic constituents of the Mediterranean diet. In this study, we have shown that treatment with HT (20mg/kg/d for 8 weeks) decreased adiposity, improved impaired glucose and insulin tolerance, improved endothelial function with lower systolic blood pressure, decreased left ventricular fibrosis and resultant diastolic stiffness and reduced markers of liver damage in a diet-induced rat model of metabolic syndrome. These results were accompanied by reduced infiltration of monocytes/macrophages into the heart with reduced biomarkers of oxidative stress. Furthermore, in an HRMS-based metabolism study of HT, we have identified 24 HT phase I and II metabolites, six of them being over-produced in high-starch, low-fat diet fed rats treated with HT compared to obese rats on high-carbohydrate, high-fat diet. These results provide direct evidence for cardioprotective effects of hydroxytyrosol by attenuation of metabolic risk factors. The implications of altered metabolism of HT in high-carbohydrate, high-fat diet fed obese rats warrant further investigation.

Phytochemical Analysis and Antioxidant Potential of the Phytonutrient-Rich Decoction of Cichorium spinosum and C. intybus.

The Cretan diet, as the basis of the Mediterranean diet, has provided traditional remedies for the general well being of people through the long-established consumption of cooked wild greens and vegetables. The intake of the water decoctions of Cichorium spinosum and Cichorium intybus in the context of the daily dietary regime in Greece has been long associated with "liver detoxifying" properties. In the current study, we performed an in-depth investigation of the water decoctions traditionally prepared from C. spinosum and C. intybus through qualitative UHPLC-HRMS profiling and direct quantification of cichoric and caftaric acid as major antioxidant components of the decoction. In addition, we developed a one-step countercurrent chromatography method for the isolation of the two phenolic acids, along with a sulfoconjugate sesquiterpene lactone present only in the Cretan C. spinosum. All water decoctions were found not to be cytotoxic in human fibroblasts, whereas they all significantly reduced the intracellular reactive oxygen species, which is consistent with the major presence of strong antioxidant compounds such as cichoric acid. This work demonstrates that the intake of these decoctions in doses suggested by Greek traditional use is comparable to the ingestion of a phytomedical preparation of antioxidants. These results contribute to our current knowledge on the beneficial health effect of the Cretan diet.

Chemical and Biological Investigation of Olive Mill Waste Water - OMWW Secoiridoid Lactones.

Olive mill waste water is the major byproduct of the olive oil industry containing a range of compounds related to Olea europaea and olive oil constituents. Olive mill waste water comprises an important environmental problem in olive oil producing countries, but it is also a valuable material for the isolation of high added value compounds. In this study, an attempt to investigate the secoiridoid content of olive mill waste water is described with the aid of ultrahigh-performance liquid chromatography-electrospray ionization (±)-high-resolution mass spectrometry and centrifugal partition chromatography methods. In total, seven secoiridoid lactones were isolated, four of which are new natural products. This is the first time that a conjugate of hydroxytyrosol and a secoiridoid lactone has been isolated from olive mill waste water and structurally characterized. Furthermore, the range of isolated compounds allowed for the proposal of a hypothesis for the biotransformation of olive secoiridoids during the production of olive mill waste water. Finally, the ability of the representative compounds to reduce the intracellular reactive oxygen species was assessed with the dichlorofluorescein assay in conjunction with the known antioxidant agent hydroxytyrosol.

Inhibition of Collagenase by Mycosporine-like Amino Acids from Marine Sources.

Matrix metalloproteinases play an important role in extracellular matrix remodeling. Excessive activity of these enzymes can be induced by UV light and leads to skin damage, a process known as photoaging. In this study, we investigated the collagenase inhibition potential of mycosporine-like amino acids, compounds that have been isolated from marine organisms and are known photoprotectants against UV-A and UV-B. For this purpose, the commonly used collagenase assay was optimized and for the first time validated in terms of relationships between enzyme-substrate concentrations, temperature, incubation time, and enzyme stability. Three compounds were isolated from the marine red algae Porphyra sp. and Palmaria palmata, and evaluated for their inhibitory properties against Chlostridium histolyticum collagenase. A dose-dependent, but very moderate, inhibition was observed for all substances and IC50 values of 104.0 µM for shinorine, 105.9 µM for porphyra, and 158.9 µM for palythine were determined. Additionally, computer-aided docking models suggested that the mycosporine-like amino acids binding to the active site of the enzyme is a competitive inhibition.

Oleocanthal Modulates Estradiol-Induced Gene Expression Involving Estrogen Receptor α.

Oleocanthal is a bioactive compound from olive oil. It has attracted considerable attention as it is anti-inflammatory, antiproliferative, and has been shown to possess neuroprotective properties in vitro and in vivo. Delineated from its polyphenolic structure, the aim of this study was to characterize oleocanthal towards estrogenic properties. This might contribute to partly explain the beneficial effects described for the Mediterranean diet. Estrogenic properties of oleocanthal were assessed by different methods: a) stimulation of reporter gene activity in MVLN or RNDA cells either expressing estrogen receptor α or ß, b) stimulation of luciferase reporter gene activity in U2OS osteosarcoma cells expressing estrogen receptor α or ß, and c) elucidation of the impact on estradiol-induced gene expression in U2OS cells transduced with both estrogen receptors. Depending on the cell line origin, oleocanthal inhibited luciferase activity (MVLN, U2OS-estrogen receptor ß) or weakly induced reporter gene activity at 10 µM in U2OS-estrogen receptor α cells. However, oleocanthal inhibited stimulation of luciferase activity by estradiol from both estrogen receptors. Oleocanthal, if given alone, did not stimulate gene expression in U2OS cells, but it significantly modulated the response of estradiol. Oleocanthal enhanced the effect of estradiol on the regulation of those genes, which are believed to be regulated through heterodimeric estrogen receptors. As the estrogenic response pattern of oleocanthal is rather unique, we compared the results obtained with oleacein. Oleocanthal binds to both estrogen receptors inducing estradiol-agonistic or antiagonistic effects depending on the cell line. Regarding regulation of gene expression in U2OS-estrogen receptor α/ß cells, oleocanthal and oleacein enhanced estradiol-mediated regulation of heterodimer-regulated genes.

Oleuropein prevents doxorubicin-induced cardiomyopathy interfering with signaling molecules and cardiomyocyte metabolism.

Oleuropein, a natural phenolic compound, prevents acute doxorubicin (DXR)-induced cardiotoxicity but there is no evidence regarding its role in chronic DXR-induced cardiomyopathy (DXR-CM). In the present study, we investigated the role of oleuropein in DXR-CM by addressing cardiac geometry and function (transthoracic echocardiography), cardiac histopathology, nitro-oxidative stress (MDA, PCs, NT), inflammatory cytokines (IL-6, Big ET-1), NO homeostasis (iNOS and eNOS expressions), kinases involved in apoptosis and metabolism (Akt, AMPK) and myocardial metabonomics. Rats were randomly divided into 6 groups: Control, OLEU-1 and OLEU-2 [oleuropein at 1000 and 2000 mg/kg in total, respectively, intraperitoneally (i.p.) for 14 days], DXR (18 mg/kg, i.p. divided into 6 equal doses for 2 weeks), DXR-OLEU-1 and DXR-OLEU-2 (both oleuropein and DXR as previously described). Impaired left ventricular contractility and inflammatory and degenerative pathology lesions were encountered only in the DXR group. The DXR group also had higher MDA, PCs, NT, IL-6 and Big ET-1 levels, higher iNOS and lower eNOS, Akt and AMPK activation compared to controls and the oleuropein-treated groups. Metabonomics depicted significant metabolite alterations in the DXR group suggesting perturbed energy metabolism and protein biosynthesis. The effectiveness of DXR in inhibiting cell proliferation is not compromised when oleuropein is present. We documented an imbalance between iNOS and eNOS expressions and a disturbed protein biosynthesis and metabolism in DXR-CM; these newly recognized pathways in DXR cardiotoxicity may help identifying novel therapeutic targets. Activation of AMPK and suppression of iNOS by oleuropein seem to prevent the structural, functional and histopathological cardiac effects of chronic DXR toxicity.

Impact of a functionalized olive oil extract on the uterus and the bone in a model of postmenopausal osteoporosis.

PURPOSE: The Mediterranean diet rich in fruits, vegetables and olive oil has been related to a lower osteoporosis incidence and accordingly to a reduced fracture risk. These observations might be mediated by the active constituents of extra virgin olive oil, and especially polyphenols. In the context of exploring the features of olive oil active constituents on postmenopausal osteoporosis, an extra virgin olive oil total polyphenolic fraction (TPF) was isolated and its effect on the bone loss attenuation was investigated. METHODS: Female Lewis rats were ovariectomized and fed a diet enriched with a total phenolic extract of extra virgin olive oil in a concentration of 800 mg/kg diet. RESULTS: Oleocanthal, one compound of the polyphenolic fraction, showed a higher relative estrogen receptor binding affinity to the ERα compared to the ERß. While the TPF only slightly induced the uterine wet weight (490.7 ± 53.7 vs. 432.7 ± 23, p = 0.058), TPF regulated estrogen response genes in the uterus (progesterone receptor, antigen identified by monoclonal antibody Ki67, complement C3). Comparing the quantified bone parameters, the oral TPF substitution did not attenuate the ovariectomy-induced bone loss. CONCLUSIONS: The administration of extra virgin olive oil polyphenols regulated uterine estrogen response marker genes in an E2-agonistic manner. The bone loss induced by estrogen ablation was not mitigated by treatment with the polyphenolic extract.

One-step semisynthesis of oleacein and the determination as a 5-lipoxygenase inhibitor.

The dialdehydes oleacein (2) and oleocanthal (4) are closely related to oleuropein (1) and ligstroside (3), the two latter compounds being abundant iridoids of Olea europaea. By exploiting oleuropein isolated from the plant leaf extract, an efficient procedure has been developed for a one-step semisynthesis of oleacein under Krapcho decarbomethoxylation conditions. Highlighted is the fact that 5-lipoxygenase is a direct target for oleacein with an inhibitory potential (IC50: 2 µM) more potent than oleocanthal (4) and oleuropein (1). This enzyme catalyzes the initial steps in the biosynthesis of pro-inflammatory leukotrienes. Taken together, the methodology presented here offers an alternative solution to isolation or total synthesis for the procurement of oleacein, thus facilitating the further development as a potential anti-inflammatory agent.

Sample preparation issues in NMR-based plant metabolomics: optimisation for Vitis wood samples.

INTRODUCTION: Nuclear magnetic resonance (NMR) is one of the most commonly used analytical techniques in plant metabolomics. Although this technique is very reproducible and simple to implement, sample preparation procedures have a great impact on the quality of the metabolomics data. OBJECTIVE: Investigation of different sample preparation methods and establishment of an optimised protocol for untargeted NMR-based metabolomics of Vitis vinifera L. wood samples. METHODS: Wood samples from two different cultivars of V. vinifera with well-defined phenotypes (Gamaret and 2091) were selected as reference materials. Different extraction solvents (successively, dichloromethane, methanol and water, as well as ethyl acetate and 7:3 methanol-water (v/v)) and deuterated solvents (methanol-d4, 7:3 chloroform-d-methanol-d4 (v/v), dimethylsulphoxide-d6 and 9:1 dimethylsulphoxide-d6-water-d2 (v/v)) were evaluated for NMR acquisition, and the spectral quality was compared. The optimal extract concentration, chemical shift stability and peak area repeatability were also investigated. RESULTS: Ethyl acetate was found to be the most satisfactory solvent for the extraction of all representative chemical classes of secondary metabolites in V. vinifera wood. The optimal concentration of dried extract was 10 mg/mL and 7:3 chloroform-d-methanol-d4 (v/v) was the most suitable solvent system for NMR analysis. Multivariate data analysis was used to estimate the biological variation and clustering between different cultivars. CONCLUSION: Close attention should be paid to all required procedures before NMR analysis, especially to the selection of an extraction solvent and a deuterated solvent system to perform an extensive metabolomic survey of the specific matrix.

Rapid identification of coumarins from Micromelum falcatum by UPLC-HRMS/MS and targeted isolation of three new derivatives.

Micromelum falcatum, a medicinal plant of the Rutaceae family, has been used in the Traditional Chinese Medicine (TCM) mainly against colds and rheumatoid arthritis. Despite its traditional use the association of its constituents with possible anti-inflammatory activity has not been explored. During this study, a rapid UPLC-ESI(+)-HRMS method was developed for the profiling of M. falcatum leave extracts and the targeted isolation of coumarin constituents. Based on chromatographic, spectroscopic and spectrometric features several 7-oxygenated coumarin derivatives were detected. After targeted isolation, eight coumarins, among them three new natural products, namely microfalcrin, microcoumaririn and micromelosidester, were purified using semi-preparative HPLC and unambiguously identified by 1 and 2D NMR. Furthermore, important spectrometric characteristics were revealed based on the HRMS and HRMS/MS spectra of the isolated 7-oxygenated coumarins facilitating their identification in complex mixtures. Finally, the anti-inflammatory properties of the extracts and representative compounds were evaluated by measuring the inhibition of the pro-inflammatory mediator NF-κB induction and nitric oxide (NO) production.

Uncovering the metabolite complexity and variability of cultivated hemp (Cannabis sativa L.): A first phytochemical diversity mapping in Greece.

The high value of fiber-type Cannabis sativa L. (hemp) due to its phytochemicals has yet to be fully recognized and leveraged. Besides cannabidiol (CBD), which is the most prevalent non-psychoactive cannabinoid, hemp contains numerous other cannabinoids with unexplored bioactivities, in addition to various compound classes. Previous works have aimed to correlate chemical profiles of C. sativa inflorescences with important parameters, mostly based on experiments under controlled conditions. However, mapping studies that explore the phytochemical diversity of hemp in a more realistic context are crucial to guide decisions at multiple levels, especially in areas where hemp cultivation was recently re-authorized, including Mediterranean countries. In this work, a powerful strategy was followed to map the phytochemical diversity of cultivated hemp in Greece, being the first study of its kind for this environment. A panel of 98 inflorescence samples, covering two harvesting years, eleven geographical regions and seven commonly used EU varieties, were studied using a combination of targeted and untargeted approaches. Quantitative results based on UPLC-PDA revealed relatively constant CBD/THC (total) ratios, while profiling by LC-HRMS effectively probed the phytochemical variability of samples, and led to the annotation of 88 metabolites, including a multitude of minor cannabinoids. Multivariate analysis substantiated a strong effect of harvesting year in sample discrimination and related biomarkers were revealed, belonging to fatty acids and flavonoids. The effect of geographical region and, especially, variety on chemical variation patterns was more intricate to interpret. The results of this work are envisioned to enhance our understanding of the real-world phytochemical complexity of C. sativa (hemp), with a view to maximized utilization of hemp for the promotion of human well-being.

Oleuropein, an anti-oxidant polyphenol constituent of olive promotes α-secretase cleavage of the amyloid precursor protein (AßPP).

Over the past decade, intense focus has been dedicated on investigating processes involved in the proteolysis of amyloid precursor protein (AßPP) and ß-amyloid (Aß) peptide metabolism, as possible targets for Alzheimer's disease (AD) therapy. To this goal, considerable research has been targeted on potential therapeutic use of compounds promoting non-amyloidogenic processing of AßPP. One of these compounds, oleuropein, a polyphenol constituent of extra virgin olive oil exhibiting a wide range of pharmacological properties, was shown to interact non-covalently with Aß, an interaction that might be related to a potential protective role of oleuropein against Aß aggregation. In the present study, it was demonstrated that oleuropein treatment of HEK293 cells stably transfected with the isoform 695 of human AßPP (APP695) leads to markedly elevated levels of sAPPα and to significant reduction of Aß oligomers. These effects were associated with increased activity of matrix metalloproteinase 9 (MMP-9), whereas no significant alterations in the expression of secretases TACE, ADAM-10 or BACE-1 were observed. Similar results were obtained using the human neuroblastoma cell line SK-N-SH. The experimental data reveal an anti-amyloidogenic effect of oleuropein and suggest a possible protective role for oleuropein against AD, extending the spectrum of beneficial properties of this naturally occurring polyphenol.