A rare olive compound oleacein functions as a TrkB agonist and mitigates neuroinflammation both in vitro and in vivo.

BACKGROUND: Neuroinflammation is widely acknowledged as a characteristic feature of almost all neurological disorders and specifically in depression- and anxiety-like disorders. In recent years, there has been significant attention on natural compounds with potent anti-inflammatory effects due to their potential in mitigating neuroinflammation and neuroplasticity. METHODS: In the present study, we aimed to evaluate the neuroprotective effects of oleacein (OC), a rare secoiridoid derivative found in extra virgin olive oil. Our goal was to explore the BDNF/TrkB neurotrophic activity of OC and subsequently assess its potential for modulating neuroinflammatory response using human neuroblastoma cells (SH-SY5Y cells) and an in vivo model of depression induced by lipopolysaccharide (LPS)-mediated inflammation. RESULTS: In SH-SY5Y cells, OC exhibited a significant dose-dependent increase in BDNF expression. This enhancement was absent when cells were co-treated with inhibitors of BDNF's receptor TrkB, as well as downstream molecules PI3K and MEK. Whole-transcriptomics analysis revealed that OC upregulated cell cycle-related genes under normal conditions, while downregulating inflammation-associated genes in LPS-induced conditions. Furthermore, surface plasmon resonance (SPR) assays demonstrated that OC exhibited a stronger and more stable binding affinity to TrkB compared to the positive control, 7,8-dihydroxyflavone. Importantly, bioluminescence imaging revealed that a single oral dose of OC significantly increased BDNF expression in the brains of Bdnf-IRES-AkaLuc mice. Furthermore, oral administration of OC at a dosage of 10 mg/kg body weight for 10 days significantly reduced immobility time in the tail suspension test compared to the LPS-treated group. RT-qPCR analysis revealed that OC significantly decreased the expression of pro-inflammatory cytokines Tnfα, Il6, and Il1ß, while simultaneously enhancing Bdnf expression, as well as both pro and mature BDNF protein levels in mice hippocampus. These changes were comparable to those induced by the positive control antidepressant drug fluoxetine. Additionally, microarray analysis of mouse brains confirmed that OC could counteract LPS-induced inflammatory biological events. CONCLUSION: Altogether, our study represents the first report on the potential antineuroinflammatory and antidepressant properties of OC via modulation of BDNF/TrkB neurotrophic activity. This finding underscores the potential of OC as a natural therapeutic agent for depression- and anxiety-related disorders.

Oleocanthal Protects C2C12 Myotubes against the Pro-Catabolic and Anti-Myogenic Action of Stimuli Able to Induce Muscle Wasting In Vivo.

Oleocanthal (OC) is a monophenol of extra-virgin olive oil (EVOO) endowed with antibiotic, cardioprotective and anticancer effects, among others, mainly in view of its antioxidant and anti-inflammatory properties. OC has been largely investigated in terms of its anticancer activity, in Alzheimer disease and in collagen-induced arthritis; however, the possibility that it can also affect muscle biology has been totally overlooked so far. This study is the first to describe that OC modulates alterations induced in C2C12 myotubes by stimuli known to induce muscle wasting in vivo, namely TNF-α, or in the medium conditioned by the C26 cachexia-inducing tumor (CM-C26). C2C12 myotubes were exposed to CM-C26 or TNF-α in the presence or absence of OC for 24 and 48 h and analyzed by immunofluorescence and Western blotting. In combination with TNF-α or CM-C26, OC was revealed to be able to restore both the myotube's original size and morphology and normal levels of both atrogin-1 and MuRF1. OC seems unable to impinge on the autophagic-lysosomal proteolytic system or protein synthesis. Modulations towards normal levels of the expression of molecules involved in myogenesis, such as Pax7, myogenin and MyHC, were also observed in the myotube cultures exposed to OC and TNF-α or CM-C26. In conclusion, the data presented here show that OC exerts a protective action in C2C12 myotubes exposed to TNF-α or CM-C26, with mechanisms likely involving the downregulation of ubiquitin-proteasome-dependent proteolysis and the partial relief of myogenic differentiation impairment.

S-(-)-Oleocanthal Ex Vivo Modulatory Effects on Gut Microbiota.

Compelling evidence points to the critical role of bioactive extra-virgin olive oil (EVOO) phenolics and gut microbiota (GM) interplay, but reliable models for studying the consequences thereof remain to be developed. Herein, we report an optimized ex vivo fecal anaerobic fermentation model to study the modulation of GM by the most bioactive EVOO phenolic S-(-)-oleocanthal (OC), and impacts therefrom, focusing on OC biotransformation in the gut. This model will also be applicable for characterization of GM interactions with other EVOO phenolics, and moreover, for a broadly diverse range of bioactive natural products. The fecal fermentation media and time, and mouse type and gender, were the major factors varied and optimized to provide better understanding of GM-OC interplay. A novel resin entrapment technique (solid-phase extraction) served to selectively entrap OC metabolites, degradation products, and any remaining fraction of OC while excluding interfering complex fecal medium constituents. The effects of OC on GM compositions were investigated via shallow shotgun DNA sequencing. Robust metabolome analyses identified GM bacterial species selectively altered (population numbers/fraction) by OC. Finally, the topmost OC-affected gut bacterial species of the studied mice were compared with those known to be extant in humans and distributions of these bacteria at different human body sites. OC intake caused significant quantitative and qualitative changes to mice GM, which was also comparable with human GM. Results clearly highlight the potential positive health outcomes of OC as a prospective nutraceutical.

EVOO Polyphenols Relieve Synergistically Autophagy Dysregulation in a Cellular Model of Alzheimer's Disease.

(1) Background: Autophagy, the major cytoplasmic process of substrate turnover, declines with age, contributing to proteostasis decline, accumulation of harmful protein aggregates, damaged mitochondria and to ROS production. Accordingly, abnormalities in the autophagic flux may contribute to many different pathophysiological conditions associated with ageing, including neurodegeneration. Recent data have shown that extra-virgin olive oil (EVOO) polyphenols stimulate cell defenses against plaque-induced neurodegeneration, mainly, through autophagy induction. (2) Methods: We carried out a set of in vitro experiments on SH-SY5Y human neuroblastoma cells exposed to toxic Aß1-42 oligomers to investigate the molecular mechanisms involved in autophagy activation by two olive oil polyphenols, oleuropein aglycone (OleA), arising from the hydrolysis of oleuropein (Ole), the main polyphenol found in olive leaves and drupes and its main metabolite, hydroxytyrosol (HT). (3) Results: Our data show that the mixture of the two polyphenols activates synergistically the autophagic flux preventing cell damage by Aß1-42 oligomers., in terms of ROS production, and impairment of mitochondria. (4) Conclusion: Our results support the idea that EVOO polyphenols act synergistically in autophagy modulation against neurodegeneration. These data confirm and provide the rationale to consider these molecules, alone or in combination, as promising candidates to contrast ageing-associated neurodegeneration.

Comparative Gene Signature of (-)-Oleocanthal Formulation Treatments in Heterogeneous Triple Negative Breast Tumor Models: Oncological Therapeutic Target Insights.

Triple negative breast cancer (TNBC) heterogeneity and limited therapeutic options confer its phenotypic aggressiveness. The discovery of anti-TNBC natural products with valid molecular target(s) and defined pharmacodynamic profile would facilitate their therapeutic nutraceutical use by TNBC patients. The extra-virgin olive oil (EVOO) is a key Mediterranean diet ingredient. S-(-)-Oleocanthal (OC) leads the bioactive anti-tumor EVOO phenolic ingredients. A previous study reported the solid dispersion formulated OC with (+)-xylitol (OC-X) suppressed the in vivo progression and recurrence of the TNBC MDA-MB-231 cells. This study investigates the ability of OC-X formulation to suppress the in vivo heterogeneous BC initiation and progression utilizing advanced preclinical transgenic MMTV-PyVT and TNBC PDX mouse models. Furthermore, the clustering of the gene expression profiles in MMTV-PyVT and PDX mouse tumors treated with OC-X acquired by a Clariom S microarray analysis identified the distinctly affected genes. Several affected novel signature genes identified in response to OC-X treatments and proved overlapped in both mouse and human tumor models, shedding some lights toward understanding the OC anticancer molecular mechanism and assisting in predicting prospective clinical outcomes. This study provides molecular and preclinical evidences of OC-X potential as a nutraceutical suppressing heterogeneous TNBC model and offers preliminary gene-level therapeutic mechanistic insights.

Asperuloside suppressing oxidative stress and inflammation in DSS-induced chronic colitis and RAW 264.7 macrophages via Nrf2/HO-1 and NF-κB pathways.

BACKGROUND: Inflammatory bowel diseases (IBDs), which mainly include Crohn's disease (CD) and ulcerative colitis (UC), are chronic idiopathic inflammatory disease of the gastrointestinal tract for which effective pharmacological treatments are lacking or options are very limited. PURPOSE: Here, we aim to investigate the therapeutic effects of an iridoid glycoside, asperuloside (ASP) on mice experimental chronic colitis induced by dextran sulfate sodium (DSS) and further explore underlying mechanisms in vitro and in vivo. METHODS: LPS-treated RAW 264.7 cells showed inflammation and were assessed for various physiological, morphological and biochemical parameters in the absence or presence of ASP. Chronic colitis was induced by 2% DSS in mice, which were used as an animal model to explore the pharmacodynamics of ASP. We detected p65 and Nrf2 pathway proteins via Western blot and RT-PCR analysis, assessed the cytokines TNF-α and IL-6 via ELISA, tested p65 and Nrf2 nuclear translocation via fluorescence. In addition, the docking affinity of ASP and p65 or Nrf2 proteins in the MOE 2015 software. RESULTS: We found that ASP attenuated weight loss, disease activity index (DAI) and colonic pathological damage in colitis mice and restored the expressions of inflammatory cytokines in the colon. In addition, ASP restored antioxidant capacity in DSS-induced chronic colitis mice and lipopolysaccharide (LPS)-stimulated RAW 264.7 cells. Furthermore, ASP suppressed oxidative stress through increasing Nrf2, HO-1 and NQO-1 proteins expressions, and down-regulated nuclear levels of p65 to inhibit DSS-induced colonic oxidative stress and inflammation. Validation of the molecular docking results also indicated that ASP interacts with Nrf2 or p65 proteins. In summary, ASP improved DSS-induced chronic colitis by alleviating inflammation and oxidative stress, activating Nrf2/HO-1 signaling and limiting NF-κB signaling pathway, which may be an effective candidate for the treatment of IBD.

Asperuloside Enhances Taste Perception and Prevents Weight Gain in High-Fat Fed Mice.

Asperuloside is an iridoid glycoside found in many medicinal plants that has produced promising anti-obesity results in animal models. In previous studies, three months of asperuloside administration reduced food intake, body weight, and adipose masses in rats consuming a high fat diet (HFD). However, the mechanisms by which asperuloside exerts its anti-obesity properties were not clarified. Here, we investigated homeostatic and nutrient-sensing mechanisms regulating food intake in mice consuming HFD. We confirmed the anti-obesity properties of asperuloside and, importantly, we identified some mechanisms that could be responsible for its therapeutic effect. Asperuloside reduced body weight and food intake in mice consuming HFD by 10.5 and 12.8% respectively, with no effect on mice eating a standard chow diet. Fasting glucose and plasma insulin were also significantly reduced. Mechanistically, asperuloside significantly reduced hypothalamic mRNA ghrelin, leptin, and pro-opiomelanocortin in mice consuming HFD. The expression of fat lingual receptors (CD36, FFAR1-4), CB1R and sweet lingual receptors (TAS1R2-3) was increased almost 2-fold by the administration of asperuloside. Our findings suggest that asperuloside might exert its therapeutic effects by altering nutrient-sensing receptors in the oral cavity as well as hypothalamic receptors involved in food intake when mice are exposed to obesogenic diets. This signaling pathway is known to influence the subtle hypothalamic equilibrium between energy homeostasis and reward-induced overeating responses. The present pre-clinical study demonstrated that targeting the gustatory system through asperuloside administration could represent a promising and effective new anti-obesity strategy.

Potential Uses of Olive Oil Secoiridoids for the Prevention and Treatment of Cancer: A Narrative Review of Preclinical Studies.

The Mediterranean diet (MD) is a combination of foods mainly rich in antioxidants and anti-inflammatory nutrients that have been shown to have many health-enhancing effects. Extra-virgin olive oil (EVOO) is an important component of the MD. The importance of EVOO can be attributed to phenolic compounds, represented by phenolic alcohols, hydroxytyrosol, and tyrosol, and to secoiridoids, which include oleocanthal, oleacein, oleuropein, and ligstroside (along with the aglycone and glycosidic derivatives of the latter two). Each secoiridoid has been studied and characterized, and their effects on human health have been documented by several studies. Secoiridoids have antioxidant, anti-inflammatory, and anti-proliferative properties and, therefore, exhibit anti-cancer activity. This review summarizes the most recent findings regarding the pharmacological properties, molecular targets, and action mechanisms of secoiridoids, focusing attention on their preventive and anti-cancer activities. It provides a critical analysis of preclinical, in vitro and in vivo, studies of these natural bioactive compounds used as agents against various human cancers. The prospects for their possible use in human cancer prevention and treatment is also discussed.

Hepatoprotective species from the Chilean medicinal flora: Junellia spathulata (Verbenaceae).

ETHNOPHARMACOLOGICAL RELEVANCE: Chilean population relies on medicinal plants for treating a wide range of illnesses, especially those of the gastrointestinal system. Junellia spathulata (Gillies & Hook.) Moldenke var. spathulata (Verbenaceae), called as "verbena-azul-de-cordilleira", is a medicinal plant native to Argentina and Chile traditionally used for treating digestive disorders. Although the species of the genus are important as therapeutic resources for the Andean population, the plants are very scarcely studied. AIMS OF THE STUDY: The purpose of the present study was to find out the main constituents and investigate the protective effect of J. spathulata against oxidative stress induced by the potent oxidant 2,2'-azobis (2-amidinopropane) dihydrochloride (AAPH) in human hepatoblastoma cells. MATERIALS AND METHODS: The crude methanol extract of J. spathulata and an iridoid obtained by chromatographic processes were tested to access the hepatoprotective effect and cytotoxicity in HepG2 cell. In addition, the reducing power of the samples and their ability to scavenge free radicals were evaluated using FRAP and ORAC assay systems. RESULTS: The iridoid asperuloside, the main compound of the crude methanol extract of J. spathulata, was isolated and identified by means of NMR analysis. The crude methanol extract of J. spathulata and asperuloside protected HepG2 cells against oxidative damage triggered by AAPH-derived free radicals. This effect can be credited to the ability of the extract and asperuloside to protect the liver cells from chemical-induced injury, which might be correlated to their free radical scavenging potential. CONCLUSIONS: This study experimentally evidenced the ethnopharmacological usefulness of J. spathulata as a treatment of digestive disorders. Our result could stimulate further investigations of hepatoprotective agents in other Chilean Junellia species.

The Inhibitory Effect of Extra Virgin Olive Oil and Its Active Compound Oleocanthal on Prostaglandin-Induced Uterine Hypercontraction and Pain-Ex Vivo and In Vivo Study.

Primary dysmenorrhea is a common occurrence in adolescent women and is a type of chronic inflammation. Dysmenorrhea is due to an increase in oxidative stress, which increases cyclooxygenase-2 (COX-2) expression, increases the concentration of prostaglandin F2α (PGF2α), and increases the calcium concentration in uterine smooth muscle, causing excessive uterine contractions and pain. The polyphenolic compound oleocanthal (OC) in extra virgin olive oil (EVOO) has been shown to have an anti-inflammatory and antioxidant effect. This study aimed to investigate the inhibitory effect of extra virgin olive oil and its active ingredient oleocanthal (OC) on prostaglandin-induced uterine hyper-contraction, its antioxidant ability, and related mechanisms. We used force-displacement transducers to calculate uterine contraction in an ex vivo study. To analyze the analgesic effect, in an in vivo study, we used an acetic acid/oxytocin-induced mice writhing model and determined uterus contraction-related signaling protein expression. The active compound OC inhibited calcium/PGF2α-induced uterine hyper-contraction. In the acetic acid and oxytocin-induced mice writhing model, the intervention of the EVOO acetonitrile layer extraction inhibited pain by inhibiting oxidative stress and the phosphorylation of the protein kinase C (PKC)/extracellular signal-regulated kinases (ERK)/ myosin light chain (MLC) signaling pathway. These findings supported the idea that EVOO and its active ingredient, OC, can effectively decrease oxidative stress and PGF2α-induced uterine hyper-contraction, representing a further treatment for dysmenorrhea.

Phytochemical and pharmacological properties of asperuloside, a systematic review.

Plants are a natural source of bioactive compounds such as secondary metabolites. These molecules, also called phytochemicals, are fundamental for plant survival and often show therapeutic properties used for the treatment of human diseases. Asperuloside is a secondary metabolite which belongs to iridoid glycosides and is commonly present in the plant family Rubiaceae. In this review we aim to summarize the scientific knowledge on asperuloside, with a special emphasis on its pharmacological properties as anti-viral, anti-malarial, anti-protozoal, anti-tumorigenic, anti-hypertensive, anti-obesity, immunomodulatory, anti-inflammatory and antioxidant agent. Preclinical studies in animal models suggest that asperuloside has therapeutic potential that could be evaluated in humans. However, despite its tangible phytochemical characteristics, no clinical trial has been performed so far. Thus, we hope that this review will facilitate scientific dissemination of asperuloside pharmacological properties and encourage researchers to evaluate both pharmacokinetic and toxicity of asperuloside in animal models. This will be the first step towards clinical studies in humans.

(-)-Oleocanthal as a Dual c-MET-COX2 Inhibitor for the Control of Lung Cancer.

Lung cancer (LC) represents the topmost mortality-causing cancer in the U.S. LC patients have overall poor survival rate with limited available treatment options. Dysregulation of the mesenchymal epithelial transition factor (c-MET) and cyclooxygenase 2 (COX2) initiates aggressive LC profile in a subset of patients. The Mediterranean extra-virgin olive oil (EVOO)-rich diet already documented to reduce multiple malignancies incidence. (-)-Oleocanthal (OC) is a naturally occurring phenolic secoiridoid exclusively occurring in EVOO and showed documented anti-breast and other cancer activities via targeting c-MET. This study shows the novel ability of OC to suppress LC progression and metastasis through dual targeting of c-MET and COX-2. Western blot analysis and COX enzymatic assay showed significant reduction in the total and activated c-MET levels and inhibition of COX1/2 activity in the lung adenocarcinoma cells A549 and NCI-H322M, in vitro. In addition, OC treatment caused a dose-dependent inhibition of the HGF-induced LC cells migration. Daily oral treatment with 10 mg/kg OC for 8 weeks significantly suppressed the LC A549-Luc progression and prevented metastasis to brain and other organs in a nude mouse tail vein injection model. Further, microarray data of OC-treated lung tumors showed a distinct gene signature that confirmed the dual targeting of c-MET and COX2. Thus, the EVOO-based OC is an effective lead with translational potential for use as a prospective nutraceutical to control LC progression and metastasis.

Inhibition of human islet amyloid polypeptide aggregation and cellular toxicity by oleuropein and derivatives from olive oil.

Loss of ß-cell function and ß-cell death is the key feature of type 2 diabetes mellitus (T2DM). One hypothesis for the mechanism of this feature is amyloid formation by the human islet amyloid polypeptide (hIAPP). Despite the global prevalence of T2DM, there are no therapeutic strategies for the treatment of or prevention of amylin amyloidosis. Clinical trials and population studies indicate the healthy virtues of the Mediterranean diet, especially the extra virgin olive oil (EVOO) found in this diet. This oil is enriched in phenolic compounds shown to be effective against several aging and lifestyle diseases. Oleuropein (Ole), one of the most abundant polyphenols in EVOO, has been reported to be anti-diabetic. Some of Ole's main derivative have attracted our interest due to their multi-targetted effects, including interference with amyloid aggregation path. However, the structure-function relationship of Ole and its metabolites in T2DM are not yet clear. We report here a broad biophysical approach and cell biology techniques that enabled us to characterize the different molecular mechanisms by which tyrosol (TYR), hydroxytyrosol (HT), oleuropein (Ole) and oleuropein aglycone (OleA) modulate the hIAPP fibrillation in vitro and their effects on cell cytotoxicity. The OleA formed by enolic acid and hydroxytyrosol moiety was found to be more active than the Ole and HT at low micromolar concentrations. We further demonstrated that OleA inhibit the cytotoxicity induced by hIAPP aggregates by protecting more the cell membrane from permeabilization and then from death. These findings highlight the benefits of consuming EVOO and the great potential of its polyphenols, mainly OleA. Moreover, they support the possibility to validate and optimize the possible pharmacological use of EVOO polyphenols for T2DM prevention and therapy and also for many other amyloid related diseases.

Anticancer molecular mechanisms of oleocanthal.

Cancer is among the leading causes of mortality worldwide. Current cancer therapies are associated with serious side effects, which further damage patients' health. Therefore, the search for new anticancer agents with no toxic effects on normal and healthy cells is of great interest. Recently, we and other groups have demonstrated that oleocanthal (OLC), a phenolic compound from extra virgin olive oil, exhibits antitumor activity in various tumor models. However, the underlying mechanisms and intracellular targets of OLC remain to be completely elucidated. This review summarizes the current advancers concerning the anticancer activity of OLC, with particular emphasis on the molecular signaling pathways modulated by this compound in different tumor cell types. The major mechanisms of action of OLC include modulation of the apoptotic pathway, the HGF/c-Met pathway, and the signal transducer and activator of transcription 3 signaling pathway, among others. Furthermore, OLC has synergistic effects with anticancer drugs in vitro. Also discussed are OLC bioavailability and its concentration in olive oil. Data summarized here will represent a database for more extensive studies aimed at providing information on molecular mechanisms against cancer induced by OLC.

Healthspan Maintenance and Prevention of Parkinson's-like Phenotypes with Hydroxytyrosol and Oleuropein Aglycone in C. elegans.

Numerous studies highlighted the beneficial effects of the Mediterranean diet (MD) in maintaining health, especially during ageing. Even neurodegeneration, which is part of the natural ageing process, as well as the foundation of ageing-related neurodegenerative disorders like Alzheimer's and Parkinson's disease (PD), was successfully targeted by MD. In this regard, olive oil and its polyphenolic constituents have received increasing attention in the last years. Thus, this study focuses on two main olive oil polyphenols, hydroxytyrosol (HT) and oleuropein aglycone (OLE), and their effects on ageing symptoms with special attention to PD. In order to avoid long-lasting, expensive, and ethically controversial experiments, the established invertebrate model organism Caenorhabditis elegans was used to test HT and OLE treatments. Interestingly, both polyphenols were able to increase the survival after heat stress, but only HT could prolong the lifespan in unstressed conditions. Furthermore, in aged worms, HT and OLE caused improvements of locomotive behavior and the attenuation of autofluorescence as a marker for ageing. In addition, by using three different C. elegans PD models, HT and OLE were shown i) to enhance locomotion in worms suffering from α-synuclein-expression in muscles or rotenone exposure, ii) to reduce α-synuclein accumulation in muscles cells, and iii) to prevent neurodegeneration in α-synuclein-containing dopaminergic neurons. Hormesis, antioxidative capacities and an activity-boost of the proteasome & phase II detoxifying enzymes are discussed as potential underlying causes for these beneficial effects. Further biological and medical trials are indicated to assess the full potential of HT and OLE and to uncover their mode of action.

Asperuloside exhibits a novel anti-leukemic activity by triggering ER stress-regulated apoptosis via targeting GRP78.

Acute myeloid leukemia (AML) is a complicated disease of hematopoietic stem cell disorders. However, its pathogenesis mechanisms and therapeutic treatments still remain vague. Asperuloside (ASP) is an iridoid glycoside found in Herba Paederiae, and is a component from traditional Chinese herbal medicine. ASP has been suggested to have various pharmacological activities, such as anti-tumor and anti-inflammation. In this study, we explored the effects of ASP on apoptosis and endoplasmic reticulum (ER) stress in human leukemia cells and in human primary leukemia blasts. ASP treatments selectively reduced the cell viability of human leukemia cells and primary leukemia blasts in a dose-dependent manner. We also found that ASP induced cell death via promoting the cleavage of Caspase-9, -3 and poly (ADP-ribose) polymerase (PARP), which was along with the loss of mitochondrial membrane potential and Cyto-c release from the mitochondria. In addition, we found that ASP significantly induced ER stress in leukemia cells by improving the protein expression levels of glucose-regulated protein of 78 kDa (GRP78), phosphorylated protein kinase RNA-like ER kinase (PERK), phosphorylated eukaryotic translation initiation factor 2 alpha (eIF2α), C/EBP homologous protein (CHOP), phosphorylated inositol-requiring enzyme 1 (p-IRE1), X-box binding protein 1 (XBP1), activating transcription factor-6 (ATF6) and cleaved Caspase-12. Moreover, ER stress suppression markedly abrogated ASP-induced apoptosis. In addition, GRP78 knockdown significantly diminished ER stress and apoptosis triggered by ASP. Importantly, co-immunoprecipitation (IP) analysis further indicated that ASP regulated the interaction between GRP78 and PERK, subsequently meditating the apoptotic cell death. In vivo leukemia xenografts finally validated ER stress and apoptosis were related to the tumor growth reduction induced by ASP. The overall survival of mice was also improved by ASP treatments, accompanied with the significantly reduced number of white blood cells and elevated red blood cells. Together, our present results showed that ASP exerted anti-leukemic effects at least partially via inducing apoptosis regulated by ER stress, and suggested that ASP might be a novel and effective therapeutic strategy for treating human leukemia.

Purified oleocanthal and ligstroside protect against mitochondrial dysfunction in models of early Alzheimer's disease and brain ageing.

As components of the Mediterranean diet (MedDiet) olive polyphenols may play a crucial role for the prevention of Alzheimer's disease (AD). Since mitochondrial dysfunction is involved in both, brain ageing and early AD, effects of 10 different purified phenolic secoiridoids (hydroxytyrosol, tyrosol, oleacein, oleuroside, oleuroside aglycon, oleuropein, oleocanthal, ligstroside, ligstroside aglycone and ligustaloside B) and two metabolites (the plant metabolite elenolic acid and the mammalian metabolite homovanillic acid) were tested in very low doses on mitochondrial function in SH-SY5Y-APP695 cells - a cellular model of early AD. All tested secoiridoids significantly increased basal adenosine triphosphate (ATP) levels in SY5Y-APP695 cells. Oleacein, oleuroside, oleocanthal and ligstroside showed the highest effect on ATP levels and were additionally tested on mitochondrial respiration. Only oleocanthal and ligstroside were able to enhance the capacity of respiratory chain complexes. To investigate their underlying molecular mechanisms, the expression of genes associated with mitochondrial biogenesis, respiration and antioxidative capacity (PGC-1α, SIRT1, CREB1, NRF1, TFAM, complex I, IV and V, GPx1, SOD2, CAT) were determined using qRT-PCR. Exclusively ligstroside increased mRNA expression of SIRT1, CREB1, complex I, and GPx1. Furthermore, oleocanthal but not ligstroside decreased Aß 1-40 levels in SH-SY5Y-APP695 cells. To investigate the in vivo effects of purified secoiridoids, the two most promising compounds (oleocanthal and ligstroside) were tested in a mouse model of ageing. Female NMRI mice, aged 12 months, received a diet supplemented with 50 mg/kg oleocanthal or ligstroside for 6 months (equivalent to 6.25 mg/kg b.w.). Young (3 months) and aged (18 months) mice served as controls. Ligstroside fed mice showed improved spatial working memory. Furthermore, ligstroside restored brain ATP levels in aged mice and led to a significant life extension compared to aged control animals. Our findings indicate that purified ligstroside has outstanding performance on mitochondrial bioenergetics in models of early AD and brain ageing by mechanisms that may not interfere with Aß production. Additionally, ligstroside expanded the lifespan in aged mice and enhanced cognitive function.

Health-promoting properties of oleocanthal and oleacein: Two secoiridoids from extra-virgin olive oil.

Extra virgin olive oil (EVOO) polyphenols, including the secoiridoids oleocanthal (OLC) and oleacein (OLE), are attracting attention because of their beneficial effects on health. Data on OLC and OLE bioavailability are scarce, as most research on EVOO polyphenols has concentrated on hydroxytyrosol, tyrosol, and oleuropein. Consequently, relevant goals for future research are the elucidation of OLC and OLE bioavailability and finding evidence for their beneficial effects through pre-clinical and clinical studies. The aim of this review is to shed light on OLC and OLE, focusing on their precursors in the olive fruit and the impact of agronomic and processing factors on their presence in EVOO. Also discussed are their bioavailability and absorption, and finally, their bioactivity and health-promoting properties.

Emerging therapeutic potential of the iridoid molecule, asperuloside: A snapshot of its underlying molecular mechanisms.

Over the years, the attention of researchers in the field of modern drug discovery and development has become further intense on the identification of active compounds from plant sources and traditional remedies, as they exhibit higher therapeutic efficacies and improved toxicological profiles. Among the large diversity of plant extracts that have been discovered and explored for their potential therapeutic benefits, asperuloside, an iridoid glycoside, has been proven to provide promising effects as a therapeutic agent for several diseases. Although, this potent substance exists in several genera, it is primarily found in plants belonging to the genus Eucommia. Recent decades have seen a surge in the research on Asperuloside, making it one of the most studied natural products in the field of medicine and pharmacology. In this review, we have attempted to study the various reported mechanisms of asperuloside that form the basis of its wide spectrum of pharmacological activities.

Inhibiting effect of oleocanthal on neuroblastoma cancer cell proliferation in culture.

We investigated the potential anticancer effects of oleocanthal (OC) on neuroblastoma cells. Cells were divided into four groups: group 1, neuroblastoma cells were treated with OC; group 2, neurons that differentiated from neuroblastoma cells were treated with phosphate-buffered saline(PBS); group 3, bone marrow derived neuronal (BMDN) cells that were differentiated from bone marrow derived mesenchymal stem cells (BMSCs) were treated with OC; group 4, BMDN cells that were differentiated from BMSCs were treated with PBS. Groups 2 and 4 were control groups. The effects of OC on cell viability, oxidative stress, neurite inhibition and apoptosis at IC50 dose were investigated using MTT analysis, i-NOS and e-NOS measurement, neurotoxicity screening test (NST) and TUNEL staining, respectively. MTT analysis demonstrated that cells were significantly less viable in group 1 than in group 3. i-NOS and e-NOS staining intensity was significantly greater in group 1 than in group 3. NST revealed that OC inhibited neurite growth in both neuroblastoma and BMND cells; inhibition was significantly less in group 3 than in group 1. Significantly more TUNEL labeled cells were found in group 1 than in group 3. We found that OC prevented growth and proliferation of neuroblastoma cells in culture by increasing oxidative stress and apoptosis. We also found that the cytotoxicity of OC is negligible in BMDN cells.