The paradox of oleuropein increase in harvested olives (Olea europea L.)

Olives are non-climacteric fruit. In a previous article, oleuropein (OE) increased substantially in fresh green olives exposed to 20 °C for 7 d, but the increases were lower in preharvest treated fruit with an ethylene synthesis inhibitor. The present aim was to investigate whether phenolic compounds, including OE, were affected by ethylene treatment in green harvested olives. Postharvest treatments with the ethylene perception inhibitor, 1 -methylcyclopropene (1-MCP) at 1.5 μL L^-1 for 12 h, and/or ethylene at 1000 μL L^-1 at 20 °C for up to 10 d were applied to fruits of 'Konservolia' cultivar. The results showed that ethylene and/or 1-MCP had similar effects on total phenolics (TP), total antioxidant capacity (TAC) and OE and these results are revealed for the first time in olives. Ethylene had no effect on green loss, but 1-MCP prevented it slightly. In all treated fruit, but not in controls, TP and TAC were increased soon after harvest and remained almost stable throughout exposure, whereas OE increased in controls and all treated at later stages (as confirmed by HPLC-DAD-ESI-MS) independently of degreening. The present experiments could be applied to studies of ethylene perception and transcription related responses in these non- climacteric fruit. In practice, harvested olives do not lose their antioxidant capacity, but the OE elevation in short-stored olives at ambient temperature might have an impact on olive products quality.

Improving in vivo conversion of oleuropein into hydroxytyrosol by oral granules containing probiotic Lactobacillus plantarum 299v and an Olea europaea standardized extract

This study reports novel food-grade granules for co-delivery of L. plantarum 299v and a standardized extract of Olea europaea leaves (Phenolea®) as oral carrier of probiotics and hydroxytyrosol. Different granule formulations containing either L. plantarum 299v (Lac), or the olive leave extract (Phe) or their combination (Lac-Phe) have been successfully produced through wet granulation employing excipients generally regarded as safe as granulating/binding agents. L. plantarum cells withstood the manufacturing process and were stable upon storage at 4 °C for more than 6 months. In vitro dissolution studies in simulated gastro-intestinal fluids showed the capability of the granules to rapidly dissolve and deliver both olive leave phenols and living L. plantarum cells. In simulated digestion conditions, Lac and Lac-Phe granules protected L. plantarum against the harsh environment of the gastro-intestinal tract. Co-administration of Lac and Phe oral granules to healthy mice provided for higher amounts of hydroxytyrosol in urines as compared to Phe granules alone, suggesting that L. plantarum 299v boosted in vivo conversion of oleuropein to hydroxytyrosol. On the other hand, PCR-assisted profiling of the Lactobacillus population in faeces obtained from mice treated with Lac or Lac plus Phe confirmed that the probiotic arrived alive to colon and was there able to exert a sort of perturbing effect on the climax colonic microflora. Overall, these results pave the way towards the development of a nutraceutical useful for combined delivery of bioactive hydroxytyrosol and probiotics to colon site.

Quantitation of Oleuropein and Related Phenolics in Cured Spanish-Style Green, California-Style Black Ripe, and Greek-Style Natural Fermentation Olives

Oleuropein, ligstroside, and related hydrolysis products are key contributors to olive bitterness, and several of these phenolics are implicated in the prevention of lifestyle age-related diseases. While table olive processing methods are designed to reduce oleuropein, the impact of processing on ligstroside and related hydrolysis products (e.g., oleacein, oleocanthal, hydroxytyrosol glucoside, ligstroside aglycone, and oleuropein aglycone) is relatively unknown. Herein, levels of these compounds were measured in Spanish-style green (SP), Californian-style black ripe (CA), and Greek-style natural fermentation (GK) olives using rapid ultrahigh-performance liquid chromatography (UHPLC) tandem mass spectrometry (MS/MS). GK olives had the highest concentration of all compounds measured, with the exception of oleocanthal, which was highest in SP olives (0.081 mg kg^-1 wet weight (w.wt)). CA olives had the lowest levels of most compounds measured, including ligstroside (0.115 mg kg^-1 w.wt) and oleuropein (0.974 mg kg^-1 w.wt). Hydroxytyrosol was the predominate compound in all three styles of commercial olives, with similar concentrations observed for GK and SP olives (134.329 and 133.685 mg kg^-1 w.wt, respectively) and significantly lower concentrations observed for CA olives (19.981 mg kg^-1 w.wt).

Olive tree (Olea europaea L.) leaf as a waste by-product of table olive and olive oil industry: a review

Research into finding new uses for by-products of table olive and olive oil industry are of great value not only to the economy but also to the environment where olives are grown and to the human health. Since leaves represent around 10% of the total weight of olives arriving at the mill, it is worth obtaining high added-value compounds from those materials for the preparation of dietary supplements, nutraceuticals, functional food ingredients or cosmeceuticals. In this review article, olive tree (Olea europaea L.) leaf is reviewed as being a potential inexpensive, renewable and abundant source of biophenols. The importance of this agricultural and industrial waste is emphasised by means of describing its availability, nutritional and therapeutic effects and studies conducted on this field. © 2017 Society of Chemical Industry.

Olive tree (Olea europaea L.) leaf as a waste by-product of table olive and olive oil industry: a review

Research into finding new uses for by-products of table olive and olive oil industry are of great value not only to the economy but also to the environment where olives are grown and to the human health. Since leaves represent around 10% of the total weight of olives arriving at the mill, it is worth obtaining high added-value compounds from those materials for the preparation of dietary supplements, nutraceuticals, functional food ingredients or cosmeceuticals. In this review article, olive tree (Olea europaea L.) leaf is reviewed as being a potential inexpensive, renewable and abundant source of biophenols. The importance of this agricultural and industrial waste is emphasised by means of describing its availability, nutritional and therapeutic effects and studies conducted on this field. © 2017 Society of Chemical Industry.

Oleuropein shows copper complexing properties and noxious effect on cultured SH-SY5Y neuroblastoma cells depending on cell copper content

The secoiridoid oleuropein is a non-flavonoid polyphenol, found in the fruit, leaves and food derivatives from Olea europea. Like other polyphenols it shows a very low toxicity towards healthy tissues and a protective action against cancer or neurodegeneration, but its mechanism of action is not yet understood. In the present report we have used optical and ESR spectroscopy as well as molecular modelling to demonstrate that oleuropein forms a complex with the transition metal copper; the dysmetabolism of this metal is suspected to be involved in both cancer and neurodegeneration. Experiments carried out with the aglycon derivative of oleuropein, produced by β-glycosidase treatment of oleuropein glycoside, showed that also the aglycon forms copper-complexes, but with different spectroscopic features than the glycosidic form. Molecular modelling analysis confirmed that two oleuropein molecules (glycosidic or aglycon forms) can easily coordinate one copper ion. The relationship between oleuropein and copper was investigated in SH-SY5Y human neuroblastoma cells. When cells were depleted of copper by treatment with the copper chelator triethylenetetramine (Trien), that binds copper with higher affinity than oleuropein, oleuropein was less toxic than to copper-adequate cells. Conversely, incubation of SH-SY5Y cells with exogenous copper sulphate increased cell susceptibility to oleuropein. Furthermore SH-SY5Y cells differentiated by retinoic acid pre-treatment showed a lower level of copper, and were more resistant to oleuropein treatment. The oleuropein aglycon was not toxic towards SH-SY5Y cells. In conclusion, the copper-oleuropein complex may be involved in the toxicity of oleuropein towards tumour cells, depending on their copper level.

Impact of high-dose oleuropein on cisplatin-induced oxidative stress, genotoxicity and pathological changes in rat stomach and lung

The current systemic treatments of the various solid tumors involve Cisplatin (CIS)-based chemotherapy. Due to its cytotoxicity, this approach is limited. Moreover, the safety of CIS is only discussed especially in breast and stomach cancers. Therefore, we, for the first time, explored the restorative efficacy of oleuropein (OLE), in stomach and lung injuries induced by CIS. Sprague-Dawley rats were divided into eight groups: control CIS, OLE and CIS + OLE. Single dose of (7 mg/kg) CIS was administered intraperitoneally to CIS and CIS + OLE groups. After 24 h, 50, 100 and 200 mg/kg OLE was given for three consecutive days to OLE and CIS + OLE groups. The 8-OH-dG, total oxidative/antioxidant status (TOS/TAS) and malondialdehyde (MDA) levels were evaluated and histopathological analyses were performed on the studied tissues. The results indicated that CIS significantly increased 8-OH-dG, MDA and TOS levels and caused severe tissue damages. However, high dose of OLE induced a significant decrease in the 8-OH-dG, MDA levels, an increase in TAS levels and it restores CIS-induced tissue damages. We hope that the results of this study will provide an impetus for future studies on novel therapeutic strategies including the protective use of oleuropein in gastric and lung cancers due to chemotherapy.

Oleuropein improves glucose tolerance and lipid profile in rats with simultaneous renovascular hypertension and type 2 diabetes

Oleuropein mediates most of the beneficial effects of olive products. This study examined the role of oxidative stress in the effects of oleuropein on lipid profile and blood glucose in rats with simultaneous renovascular hypertension and type 2 diabetes. Eight groups (n = 7-9 each) of male Sprague-Dawley rats including a control, a type 2 diabetic, a renovascular hypertensive, a sham, a simultaneously hypertensive diabetic receiving vehicle, and 3 simultaneously hypertensive-diabetic receiving 20, 40, or 60 mg/kg/day oleuropein were used. Four weeks after treatment, blood glucose, lipid profile, and biomarkers of oxidative stress were measured, and glucose tolerance test (GTT) was performed. Simultaneously hypertensive diabetic rats had significantly higher blood pressure, blood glucose, and serum total cholesterol, low-density lipoprotein cholesterol (LDL-C), triglyceride and malondialdehyde. They also had lower serum high-density lipoprotein cholesterol, erythrocyte superoxide dismutase, and impaired glucose tolerance. Oleuropein significantly reduced blood pressure, blood glucose, and serum total cholesterol, LDL-C, triglyceride and malondoaldehyde. It also increased serum high-density lipoprotein cholesterol, erythrocyte superoxide dismutase, and improved glucose tolerance. The findings show that the model is associated with impaired glucose tolerance, and adverse lipid profile. They also show that oleuropein, partly by an antioxidant mechanism, improves glucose tolerance and changed lipid profile favorably.

Anticancer effects of oleuropein

Cancer cells exhibit enhanced proliferation rate and a resistance to apoptosis. Epidemiological studies suggest that olive oil intake is associated with a reduced risk of cancer. Olive oil, olives, and olive leaves contain many polyphenols, including oleuropein. Recently, several studies have demonstrated that oleuropein inhibits proliferation and induces apoptosis in different cancer cell lines. In addition, anticancer effects of oleuropein have been seen in animal studies. These effects are associated with oleuropein's ability to modulate gene expression and activity of a variety of different signaling proteins that play a role in proliferation and apoptosis. This article summarizes the existing in vitro and in vivo studies focusing on the anticancer effects of oleuropein and its effects on key signaling molecules. © 2017 BioFactors, 43(4):517-528, 2017.

The C-Domain of Oleuropein β-Glucosidase Assists in Protein Folding and Sequesters the Enzyme in Nucleus

Oleuropein, a terpene-derived glycosylated secoiridoid biosynthesized exclusively by members of the Oleaceae family, is involved in a two-component defense system comprising a β-glucosidase that activates oleuropein into a toxic glutaraldehyde-like structure. Oleuropein and its deglycosylated derivatives have high pharmaceutical interest. In this study we determined that the in planta heterologous expressed OeGLU, an oleuropein-specific β-glucosidase from olive (Olea europaea), had enzymatic kinetics similar to the olive native enzyme. The C terminus encompassing the nuclear localization signal sequesters the enzyme in the nucleus, and predetermines the protein-protein recognition and homodimerization. Biochemical analysis revealed that OeGLU is a homomultimer with high M_r In silico prediction modeling of the complex structure and bimolecular fluorescence complementation analyses revealed that the C terminus of OeGLU is essential for the proper assembly of an octameric form, a key conformational feature that determines the activity of the enzyme. Our results demonstrate that intrinsic characteristics of the OeGLU ensure separation from oleuropein and keep the dual-partner defensive system conditionally inactive. Upon cell destruction, the dual-partner defense system is activated and olive massively releases the arsenal of defense.

Bioactivity Improvement of Olea europaea Leaf Extract Biotransformed by Wickerhamomyces anomalus Enzymes

Olive leaves represent a quantitatively significant by-product of agroindustry. They are rich in phenols, mainly oleuropein, which can be hydrolyzed into several bioactive compounds, including hydroxytyrosol. In this study, water extract from olive leaves 'Biancolilla' was analyzed for polyphenol profile, DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity and protective effect on differentiated Caco-2 cells. The efficacy of two enzymatic treatments in promoting the release of bioactive phenols was investigated: a) enzymatic extract from Wickerhamomyces anomalus, characterized by β-glucosidase and esterase activities; b) commercial β-glucosidase. Composition and bioactivity of the resulting extracts were compared. The results showed that the yeast-treated extract presented hydroxytyrosol content and DPPH radical scavenging activity comparable to those obtained using commercial β-glucosidase; however, it was showed the additional presence of hydroxycinnamic acids. In experiments on Caco-2 cells, the leaf extracts promoted the recovery of cell membrane barrier at different minimum effective concentrations. The high specificity of W. anomalus enzymatic extract may represent an effective tool for the release of bioactive phenols from olive by-products.

Impact of phenolic-rich olive leaf extract on blood pressure, plasma lipids and inflammatory markers: a randomised controlled trial

PURPOSE

Dietary polyphenols have been demonstrated to favourably modify a number of cardiovascular risk markers such as blood pressure (BP), endothelial function and plasma lipids. We conducted a randomised, double-blind, controlled, crossover trial to investigate the effects of a phenolic-rich olive leaf extract (OLE) on BP and a number of associated vascular and metabolic measures.

METHODS

A total of 60 pre-hypertensive [systolic blood pressure (SBP): 121-140 mmHg; diastolic blood pressure (DBP): 81-90 mmHg] males [mean age 45 (±SD 12.7 years, BMI 26.7 (±3.21) kg/m2] consumed either OLE (136 mg oleuropein; 6 mg hydroxytyrosol) or a polyphenol-free control daily for 6 weeks before switching to the alternate arm after a 4-week washout.

RESULTS

Daytime [-3.95 (±SD 11.48) mmHg, p = 0.027] and 24-h SBP [-3.33 (±SD 10.81) mmHg, p = 0.045] and daytime and 24-h DBP [-3.00 (±SD 8.54) mmHg, p = 0.025; -2.42 (±SD 7.61) mmHg, p = 0.039] were all significantly lower following OLE intake, relative to the control. Reductions in plasma total cholesterol [-0.32 (±SD 0.70) mmol/L, p = 0.002], LDL cholesterol [-0.19 (±SD 0.56) mmol/L, p = 0.017] and triglycerides [-0.18 (±SD 0.48), p = 0.008] were also induced by OLE compared to control, whilst a reduction in interleukin-8 [-0.63 (±SD 1.13) pg/ml; p = 0.026] was also detected. Other markers of inflammation, vascular function and glucose metabolism were not affected.

CONCLUSION

Our data support previous research, suggesting that OLE intake engenders hypotensive and lipid-lowering effects in vivo.

Effect of light irradiation on the antioxidant stability of oleuropein

The stability of oleuropein, a natural antioxidant from Olea europaea, has been often studied in connection with thermal or enzymatic treatments, but very little is known about the effects of UV light. This work aimed at studying the UV-C effects on oleuropein standard solutions once dissolved in ethanol or water. During irradiation, aliquots were taken and analyzed by a flow injection system equipped with a multi-channel coulometric detector and a high-resolution mass spectrometer. The effects of irradiation were also studied by UV spectroscopy. The results show that oleuropein is relatively stable in water or ethanol, but that under UV-C light undergoes a series of fast decomposition reactions leading to hydroxytyrosol and elenolic acid. Overall, this study provides evidences that the degradation of oleuropein by UV-C light follows a mechanism dependent on the solvent used. Moreover, the solvent affects the resulting redox properties of the solution.

Soft-MS and Computational Mapping of Oleuropein

Olive oil and table olives are rich sources of biophenols, which provides a unique taste, aroma and potential health benefits. Specifically, green olive drupes are enriched with oleuropein, a bioactive biophenol secoiridoid. Olive oil contains hydrolytic derivatives such as hydroxytyrosol, oleacein and elenolate from oleuropein as well as tyrosol and oleocanthal from ligstroside. Biophenol secoiridoids are categorized by the presence of elenoic acid or its derivatives in their molecular structure. Medical studies suggest that olive biophenol secoiridoids could prevent cancer, obesity, osteoporosis, and neurodegeneration. Therefore, understanding the biomolecular dynamics of oleuropein can potentially improve olive-based functional foods and nutraceuticals. This review provides a critical assessment of oleuropein biomolecular mechanism and computational mapping that could contribute to nutrigenomics.

Oleuropein and Cancer Chemoprevention: The Link is Hot

Cancer comprises a collection of related diseases characterized by the existence of altered cellular pathways resulting in an abnormal tendency for uncontrolled growth. A broad spectrum, coordinated, and personalized approach focused on targeting diverse oncogenic pathways with low toxicity and economic natural compounds can provide a real benefit as a chemopreventive and/or treatment of this complex disease. Oleuropein, a bioactive phenolic compound mainly present in olive oil and other natural sources, has been reported to modulate several oncogenic signalling pathways. This review presents and critically discusses the available literature about the anticancer and onco-suppressive activity of oleuropein and the underlying molecular mechanisms implicated in the anticarcinogenic and therapeutic effects. The existence of limitations and the promising perspectives of research on this phenolic compound are also critically analyzed and discussed.

Oleuropein Decreases Cyclooxygenase-2 and Interleukin-17 Expression and Attenuates Inflammatory Damage in Colonic Samples from Ulcerative Colitis Patients

Oleuropein (OLE) is the major phenolic secoiridoid of olive tree leaves, and its antioxidant and anti-inflammatory activities have been demonstrated in in vitro and in vivo animal models. The aim of this study was to investigate the activity of OLE in the colonic mucosa from patients with ulcerative colitis (UC). Biopsies obtained during colonoscopy from 14 patients with active UC were immediately placed in an organ culture chamber and challenged with lipopolysaccharide from Escherichia coli (EC-LPS) at 1 μg/mL in the presence or absence of 3 mM OLE. The expression of cyclooxygenase (COX)-2 and interleukin (IL)-17 was assessed in total protein extracts from treated colonic biopsies by Western blotting. Levels of IL-17 were also measured in culture supernatant by ELISA. A microscopic evaluation of the cultured biopsies was performed by conventional histology and immunohistochemistry. The expression of COX-2 and IL-17 were significantly lower in samples treated with OLE + EC-LPS compared with those treated with EC-LPS alone (0.80 ± 0.15 arbitrary units (a.u.) vs. 1.06 ± 0.19 a.u., p = 0.003, and 0.71 ± 0.08 a.u. vs. 1.26 ± 0.42 a.u., p = 0.03, respectively) as were the levels of IL-17 in culture supernatants of OLE + EC-LPS treated colonic samples (21.16 ± 8.64 pg/mL vs. 40.67 ± 9.24 pg/mL, p = 0.01). Histologically, OLE-treated colonic samples showed an amelioration of inflammatory damage with reduced infiltration of CD3, CD4, and CD20 cells, while CD68 numbers increased. The anti-inflammatory activity of OLE was demonstrated in colonic biopsies from UC patients. These new data support a potential role of OLE in the treatment of UC.

Establishment of a suite of assays that support the discovery of proteasome stimulators

BACKGROUND

The proteasome catalyzes the degradation of many mis-folded proteins, which are otherwise cytotoxic. There is interest in the discovery of proteasome agonists, but previous efforts to do so have been disappointing.

METHODS

The cleavage of small fluorogenic peptides is used routinely as an assay to screen for proteasome modulators. We have developed follow-on assays that employ more physiologically relevant substrates.

RESULTS

To demonstrate the efficacy of this workflow, the NIH Clinical Collection (NCC) was screened. While many compounds stimulated proteasome-mediated proteolysis of the pro-fluorogenic peptide substrates, most failed to evince activity in assays with larger peptide or protein substrates. We also show that two molecules claimed previously to be proteasome agonists, oleuropein and betulinic acid, indeed accelerate hydrolysis of the fluorogenic substrate, but have no effect on the turnover of a mis-folded protein in vitro or in cellulo. However, two small molecules from the NCC, MK-866 and AM-404, stimulate the proteasome-mediated turnover of a mis-folded protein in living cells by 3- to 4-fold.

CONCLUSION

Assays that monitor the proteasome-mediated degradation of larger peptides and proteins can distinguish bona fide agonists from compounds only able to stimulate the cleavage of short, non-physiologically relevant peptides.

GENERAL SIGNIFICANCE

A suite of assays has been established that allows the discovery of bona fide proteasome agonists. AM-404 and MK-866 can be useful tools for cell culture experiments, and can serve as scaffolds to generate more potent 20S stimulators.

Oleuropein attenuates cognitive dysfunction and oxidative stress induced by some anesthetic drugs in the hippocampal area of rats

The present study was designed to evaluate the antioxidant effects of oleuropein against oxidative stress in the hippocampal area of rats. We used seven experimental groups as follows: Control, Propofol, Propofol-Ketamine (Pro.-Ket.), Xylazine-Ketamine (Xyl.-Ket.), and three oleuropein-pretreated groups (Ole.-Pro., Ole.-Pro.-Ket. and Ole.-Xyl.-Ket.). The oleuropein-pretreated groups received oleuropein (15 mg/kg body weight as orally) for 10 consecutive days. Propofol 100 mg/kg, xylazine 3 mg/kg, and ketamine 75 mg/kg once as ip was used on the 11th day of treatment. Spatial memory impairment and antioxidant status of hippocampus were measured via Morris water maze, lipid peroxidation marker, and antioxidant enzyme activities. Spatial memory impairment and lipid peroxidation significantly increased in Xyl.-Ket.-treated rats in comparison to the control, propofol, Ole.-Pro. and Ole.-Pro.-Ket. groups. Oleuropein pretreatment significantly reversed spatial memory impairment and lipid peroxidation in the Ole.-Xyl.-Ket. group as compared to the Xyl.-Ket.-treated rats. There was no significant difference between the control and the propofol group in lipid peroxidation and spatial memory status. Superoxide dismutase and catalase activities both significantly decreased in Xyl.-Ket.-treated rats when compared to the control, propofol, Ole.-Pro., Ole.-Pro.-Ket., and Ole.-Xyl.-Ket. groups. In contrast, glutathione peroxidase activity in Xyl.-Ket.-treated rats significantly increased as compared to the control, propofol, Pro.-Ket., Ole.-Pro., and Ole.-Pro.-Ket. groups. We concluded that xylazine in combination with ketamine is an oxidative anesthetic drug and oleuropein pretreatment attenuates cognitive dysfunction and oxidative stress induced by anesthesia in the hippocampal area of rats. We also confirmed the antioxidant properties of propofol as a promising antioxidant anesthetic agent.

Kinetic improvement of olive leaves' bioactive compounds extraction by using power ultrasound in a wide temperature range

In this study, the effect of temperature and ultrasonic application on extraction kinetics of polyphenols from dried olive leaf was investigated. Conventional (CVE) and ultrasonic-assisted extraction (UAE) were performed at 10, 20, 30, 50 and 70°C using water as solvent. Extracts were characterized by measuring the total phenolic content, the antioxidant capacity and the oleuropein content (HPLC-DAD/MS-MS). Moreover, Naik's model was used to mathematically describe the extraction kinetics. The experimental results showed that phenolic extraction was faster in UAE (ultrasonic-assisted extraction) than in CVE (conventional extraction), being extraction kinetics satisfactorily described using Naik model (include VAR>98%). Besides, the total phenolic content, the antioxidant capacity and the oleuropein content were significantly (p<0.05) improved by increasing the temperature in both CVE and UAE. Oleuropein content reached 6.57±0.18 being extracted approximately 88% in the first minute for UAE experiments.

The Health Benefiting Mechanisms of Virgin Olive Oil Phenolic Compounds

Virgin olive oil (VOO) is credited as being one of the many healthful components associated with the Mediterranean diet. Mediterranean populations experience reduced incidence of chronic inflammatory disease states and VOO is readily consumed as part of an everyday Mediterranean dietary pattern. VOO is rich in phenolic compounds and the health promoting benefits of these phenolics are now established. Recent studies have highlighted the biological properties of VOO phenolic compounds elucidating their anti-inflammatory activities. This paper will review current knowledge on the anti-inflammatory and nutrigenomic, chemoprotective and anti-atherosclerotic activities of VOO phenolics. In addition the concentration, metabolism and bioavailability of specific phenolic compounds will be discussed. The evidence presented in the review concludes that oleurepein, hydroxytyrosol and oleocanthal have potent pharmacological activities in vitro and in vivo; however, intervention studies with biologically relevant concentrations of these phenolic compounds are required.

Neuroprotective effects of oleuropein against cognitive dysfunction induced by colchicine in hippocampal CA1 area in rats

Alzheimer's disease is a progressive neurodegenerative disorder with decline in memory. The role of oxidative stress is well known in the pathogenesis of the disease. The purpose of this study was to evaluate pretreatment effects of oleuropein on oxidative status and cognitive dysfunction induced by colchicine in the hippocampal CA1 area. Male Wistar rats were pretreated orally once daily for 10 days with oleuropein at doses of 10, 15 and 20 mg/kg. Thereafter, colchicine (15 μg/rat) was administered into the CA1 area of the hippocampus to induce cognitive dysfunction. The Morris water maze was used to assess learning and memory. Biochemical parameters such as glutathione peroxidase and catalase activities, nitric oxide and malondialdehyde concentrations were measured to evaluate the antioxidant status in the rat hippocampus. Our results indicated that colchicine significantly impaired spatial memory and induced oxidative stress; in contrast, oleuropein pretreatment significantly improved learning and memory retention, and attenuated the oxidative damage. The results clearly indicate that oleuropein has neuroprotective effects against colchicine-induced cognitive dysfunction and oxidative damage in rats.

Oleuropein Prevents Neuronal Death, Mitigates Mitochondrial Superoxide Production and Modulates Autophagy in a Dopaminergic Cellular Model

Parkinson’s disease (PD) is a progressive neurodegenerative disorder, primarily affecting dopaminergic neurons in the substantia nigra. There is currently no cure for PD and present medications aim to alleviate clinical symptoms, thus prevention remains the ideal strategy to reduce the prevalence of this disease. The goal of this study was to investigate whether oleuropein (OLE), the major phenolic compound in olive derivatives, may prevent neuronal degeneration in a cellular dopaminergic model of PD, differentiated PC12 cells exposed to the potent parkinsonian toxin 6-hydroxydopamine (6-OHDA). We also investigated OLE’s ability to mitigate mitochondrial oxidative stress and modulate the autophagic flux. Our results obtained by measuring cytotoxicity and apoptotic events demonstrate that OLE significantly decreases neuronal death. OLE could also reduce mitochondrial production of reactive oxygen species resulting from blocking superoxide dismutase activity. Moreover, quantification of autophagic and acidic vesicles in the cytoplasm alongside expression of specific autophagic markers uncovered a regulatory role for OLE against autophagic flux impairment induced by bafilomycin A1. Altogether, our results define OLE as a neuroprotective, anti-oxidative and autophagy-regulating molecule, in a neuronal dopaminergic cellular model.

[Study on Gentiana Rigescens with Silvomedicinal and Agriosivomedicinal Systems with FTIR Spectroscopy]

Multiple cropping systems are the way to cope with the shortage of traditional Chinese medicine (TCM) resources and enhance the utilization ratio of land. The aim of this study was to investigate seventy Gentiana rigescens Franch samples which were planted in slope and in multiple cropping system mixed with Juglans regia, Alnus nepalensis, Eucalyptus robusta, Alnus nepalensis, Camellia sinensis, Chaenomeles sinensis using Fourier transform infrared (FTIR) spectroscopy. The pretreatments such as baseline correction, normalization and second derivative of all the original spectra were performed with Omnic 8.0 software. Moreover, second derivative spectra of samples and gentiopicroside standard were analyzed. In addition, two spectral databases were set up based on the average spectra of every variety with Omnic 8.0 software. The first library (Lib1) which included the spectra region from 1 800 to 600 cm-1 had the algorithm of expert retrieve while the correlation retrieve and square differential retrieve were dealt with the second library (Lib2) in the full spectral range. The results indicated that it is difficult to identify the infrared spectra of samples directly because they had high similarities. There were multiple common peaks between spectra of samples and gentiopicroside standards. The absorption peaks of 1 611 and 1 076 cm-1 of gentiopicroside were the two main characteristic peaks in the second derivative spectra. The difference of peak shape of every sample in the wave number of 1 076 cm-1 was small. By comparing peak area at 1 611 cm-1, the samples planted with J. regia contained highest content of gentiopicroside while the content of this effective constituent was the lowest in the samples which were planted in the slope and in the multiple cropping systems mixed with C sinensis. The differences of effective components in the samples with different planting patterns were represented by the variances of spectral matching values. The difference of matching values of samples planted with J. regia, A. nepalensis, E. Robusta and A. nepalensis were lower than that with slope and C. Sinensis. The number of misjudgment of expert retrieval, correlation retrieve and square differential retrieve were 11, 4 and 9, respectively. The discrimination result of correlation retrieve was the best in the full spectral range and the correct recognition rate was 94.29%. Fourier transforms infrared (FTIR) spectroscopy combined with second derivative and retrieval had good ability to discriminate G. rigescens with different cropping systems. It could provide a basis for the discrimination of different planting patterns of TCM

Oleuropein ameliorates arsenic induced oxidative stress in mice

The objective of this study is to investigate the potential preventive effect of oleuropein in an experimental arsenic toxicity in mice. For this purpose, mice were exposed to 5mg/kg/day sodium arsenite (NaAsO2) in drinking water and treated with 30mg/kg/day oleuropein for 15 days. At the end of the experiment, animals were sacrificed and selected organs were processed for biochemical and histopahtological investigations. Blood, liver, kidney and brain malondialdehyde (MDA) and nitric oxide (NO) levels were determined by colorimetric methods. Protein carbonyl content is measured by a commercial kit. Liver morphology and immunoreactivity for inducible NOS (iNOS) and endothelial NOS (eNOS) was evaluated microscopically. Level of NO was determined to decrease in blood and tissues whereas MDA increased in arsenic given mice. Tissue protein carbonyl content also increased in this group. Immunoreactivity for iNOS and eNOS was noted to increase with arsenic treatment. Oleuropein treatment had significant effects in normalizing the MDA and NO levels as well as protein carbonyl content. Immunohistochemical staining also showed reduction of the expression of iNOS and eNOS in liver. The results indicate that oleuropein ameliorates oxidative tissue damage by scavenging free radicals.

[Research on Breeding of the New Rehmannia glutinosa Variety]

OBJECTIVE

To breed new Rehmannia glutinosa varieties with best comprehensive properties.

METHODS

By space mutation of hybrid seeds of 85-5 and Beijing No. 1,after systemic breeding, Huaidi 81 with excellent comprehensive characters was screened. Fresh weight, benchmark composition content, resistance, chlorophyll and anthocyanin content, photosynthetic characteristics of the new variety and the main cultivars were determined.

RESULTS

Per plant fresh weight of Huaidi 81 was higher than those five main varieties and there was extremely significant difference between Huaidi 81 and other varieties,the yield of Huaidi 81( 82 353 kg / hm2) was29. 7% higher than that 5 main varieties. The catalpol content of different Rehmannia glutinosa varieties ranked in the order as follows, Beijing No. 3( 1. 601%) > Qinhuai( 1. 588%) > Huaidi 81( 1. 314%) > Godden nine > 85-5( 1. 073%) > Huaifeng( 0. 924%),the catalpol content of Huaidi 81 was in the middle, and there was no significant difference between Huaidi 81 and Godden nine,but extremely significant difference from other varieties. The acteoside content of different Rehmannia glutinosa varieties ranked in the order as follows,Huaidi 81( 0. 096%) > Qin Huai( 0. 069%) > 85-5( 0. 047%) > Beijing No. 3( 0. 035%) > Huaifeng( 0. 023%) > Golden nine( 0. 022%),the content of acteoside of Huaidi 81 was higher than those five main varieties, and there was extremely significant difference between Huaidi 81 and other varieties. Huaidi 81 had high resistance to Septoris digitalis, and had middle resistance to leaf ring rot, which indicated that Huaidi 81 had good resistance to leaf disease. Huaidi 81 with the highest chlorophyll content and moderate anthocyanin content, and had the highest photosynthetic rate.

CONCLUSION

The new variety Huaidi 81 with best comprehensive properties is suitable for popularizing as a new Rehmannia glutinosa variety.