Lampaya Medicinalis Phil. decreases lipid-induced triglyceride accumulation and proinflammatory markers in human hepatocytes and fat body of Drosophila melanogaster.

BACKGROUND: Excess hepatic triglyceride (TG) accumulation (steatosis) commonly observed in obesity, may lead to non-alcoholic fatty liver disease (NAFLD). Altered regulation of intracellular lipid droplets (LD) and TG metabolism, as well as activation of JNK-mediated proinflammatory pathways may trigger liver steatosis-related disorders. Drosophila melanogaster is an animal model used for studying obesity and its associated disorders. In Drosophila, lipids and glycogen are stored in the fat body (FB), which resembles mammalian adipose tissue and liver. Dietary oversupply leads to obesity-related disorders, which are characterized by FB dysfunction. Infusions of Lampaya medicinalis Phil. (Verbenaceae) are used in folk medicine of Chile to counteract inflammatory diseases. Hydroethanolic extract of lampaya (HEL) contains considerable amounts of flavonoids that may explain its anti-inflammatory effect. METHODS: We studied whether HEL affects palmitic acid (PA, C16:0) and oleic acid (OA; C18:1)-induced TG accumulation and proinflammatory marker content in HepG2 hepatocytes as well as impaired lipid storage and proinflammatory molecule expression in Drosophila melanogaster fed a high-fat diet (HFD). RESULTS: In HepG2 hepatocytes, exposure to OA/PA elevated TG content, FABP4, ATGL and DGAT2 expression, and the JNK proinflammatory pathway, as well as TNF-α and IL-6 production, while diminished FAS expression. These effects were prevented by HEL co-treatment. In Drosophila larvae fed a HFD, HEL prevented TG accumulation and downregulated proinflammatory JNK pathway activation. CONCLUSION: HEL effect counteracting OA/PA- and HFD-induced lipid accumulation and proinflammatory marker expression in HepG2 hepatocytes and Drosophila larvae may represent a preventive approach against hepatic steatosis and inflammation, associated to obesity and NAFLD.

Obesity-Associated Inflammation: Does Curcumin Exert a Beneficial Role?

Curcumin is a lipophilic polyphenol, isolated from the plant turmeric of Curcuma longa. Curcuma longa has always been used in traditional medicine in Asian countries because it is believed to have numerous health benefits. Nowadays it is widely used as spice component and in emerging nutraceutical food worldwide. Numerous studies have shown that curcumin possesses, among others, potential anti-inflammatory properties. Obesity represents a main risk factor for several chronic diseases, including type 2 diabetes, cardiovascular disease, and some types of cancer. The establishment of a low-grade chronic inflammation, both systemically and locally in adipose tissue, occurring in obesity most likely represents a main factor in the pathogenesis of chronic diseases. The molecular mechanisms responsible for the onset of the obesity-associated inflammation are different from those involved in the classic inflammatory response caused by infections and involves different signaling pathways. The inflammatory process in obese people is triggered by an inadequate intake of nutrients that produces quantitative and qualitative alterations of adipose tissue lipid content, as well as of various molecules that act as endogenous ligands to activate immune cells. In particular, dysfunctional adipocytes secrete inflammatory cytokines and chemokines, the adipocytokines, able to recruit immune cells into adipose tissue, amplifying the inflammatory response also at systemic level. This review summarizes the most recent studies focused at elucidating the molecular targets of curcumin activity responsible for its anti-inflammatory properties in obesity-associated inflammation and related pathologies.

Interaction between Gut Microbiota and Curcumin: A New Key of Understanding for the Health Effects of Curcumin.

Curcumin, a lipophilic polyphenol contained in the rhizome of Curcuma longa (turmeric), has been used for centuries in traditional Asian medicine, and nowadays it is widely used in food as dietary spice worldwide. It has received considerable attention for its pharmacological activities, which appear to act primarily through anti-inflammatory and antioxidant mechanisms. For this reason, it has been proposed as a tool for the management of many diseases, among which are gastrointestinal and neurological diseases, diabetes, and several types of cancer. However, the pharmacology of curcumin remains to be elucidated; indeed, a discrepancy exists between the well-documented in vitro and in vivo activities of curcumin and its poor bioavailability and chemical instability that should limit any therapeutic effect. Recently, it has been hypothesized that curcumin could exert direct regulative effects primarily in the gastrointestinal tract, where high concentrations of this polyphenol have been detected after oral administration. Consequently, it might be hypothesized that curcumin directly exerts its regulatory effects on the gut microbiota, thus explaining the paradox between its low systemic bioavailability and its wide pharmacological activities. It is well known that the microbiota has several important roles in human physiology, and its composition can be influenced by a multitude of environmental and lifestyle factors. Accordingly, any perturbations in gut microbiome profile or dysbiosis can have a key role in human disease progression. Interestingly, curcumin and its metabolites have been shown to influence the microbiota. It is worth noting that from the interaction between curcumin and microbiota two different phenomena arise: the regulation of intestinal microflora by curcumin and the biotransformation of curcumin by gut microbiota, both of them potentially crucial for curcumin activity. This review summarizes the most recent studies on this topic, highlighting the strong connection between curcumin and gut microbiota, with the final aim of adding new insight into the potential mechanisms by which curcumin exerts its effects.

Hydroethanolic Extract of Lampaya Medicinalis Phil. (Verbenaceae) Decreases Proinflammatory Marker Expression in Palmitic Acid-exposed Macrophages.

BACKGROUND: Obesity is a major health problem associated with increased comorbidities, which are partially triggered by inflammation. Proinflammatory macrophage infiltration in adipose tissue of individuals with obesity increases chronic inflammation. Obesity is associated with elevated plasma levels of saturated fatty acids, such as palmitic acid (PA), which promotes inflammation in vivo and in vitro. Infusions of Lampaya medicinalis Phil. (Verbenaceae) are used in the folk medicine of Northern Chile to counteract inflammation of rheumatic diseases. Hydroethanolic extract of lampaya (HEL) contains spectrophotometrically defined compounds that may contribute to the observed effect on inflammation. METHODS: We evaluated the phytochemical composition of HEL by high-performance liquid chromatography coupled to diode array detection (HPLC-DAD) and liquid chromatography-electrospray ionization- tandem mass spectrometry (LC-ESI-MS/MS). We assessed whether the exposure to HEL affects PA-induced expression of proinflammatory factors in THP-1 macrophages. RESULTS: HPLC-DAD and LC-ESI-MS/MS analyses showed the presence of considerable amounts of flavonoids in HEL. The PA-induced phosphorylation of the inflammatory pathway mediators IKK and NF-κB, as well as the elevated expression and secretion of proinflammatory cytokines (IL-6, TNF-α), were reduced in cells pre-exposed to HEL. CONCLUSION: These findings give new insights about the effect of HEL reducing IKK/NF-κB proinflammatory pathway, likely explained by the number of flavonoids contained in the extract. More studies would be needed to define the possible role of Lampaya as a preventive approach in subjects with obesity whose circulating PA might contribute to chronic inflammation.

Transcriptome Profiles of Human Visceral Adipocytes in Obesity and Colorectal Cancer Unravel the Effects of Body Mass Index and Polyunsaturated Fatty Acids on Genes and Biological Processes Related to Tumorigenesis.

Obesity, a low-grade inflammatory condition, represents a major risk factor for the development of several pathologies including colorectal cancer (CRC). Although the adipose tissue inflammatory state is now recognized as a key player in obesity-associated morbidities, the underlying biological processes are complex and not yet precisely defined. To this end, we analyzed transcriptome profiles of human visceral adipocytes from lean and obese subjects affected or not by CRC by RNA sequencing (n = 6 subjects/category), and validated selected modulated genes by real-time qPCR. We report that obesity and CRC, conditions characterized by the common denominator of inflammation, promote changes in the transcriptional program of adipocytes mostly involving pathways and biological processes linked to extracellular matrix remodeling, and metabolism of pyruvate, lipids and glucose. Interestingly, although the transcriptome of adipocytes shows several alterations that are common to both disorders, some modifications are unique under obesity (e.g., pathways associated with inflammation) and CRC (e.g., TGFß signaling and extracellular matrix remodeling) and are influenced by the body mass index (e.g., processes related to cell adhesion, angiogenesis, as well as metabolism). Indeed, cancer-induced transcriptional program is deeply affected by obesity, with adipocytes from obese individuals exhibiting a more complex response to the tumor. We also report that in vitro exposure of adipocytes to ω3 and ω6 polyunsaturated fatty acids (PUFA) endowed with either anti- or pro-inflammatory properties, respectively, modulates the expression of genes involved in processes potentially relevant to carcinogenesis, as assessed by real-time qPCR. All together our results suggest that genes involved in pyruvate, glucose and lipid metabolism, fibrosis and inflammation are central in the transcriptional reprogramming of adipocytes occurring in obese and CRC-affected individuals, as well as in their response to PUFA exposure. Moreover, our results indicate that the transcriptional program of adipocytes is strongly influenced by the BMI status in CRC subjects. The dysregulation of these interrelated processes relevant for adipocyte functions may contribute to create more favorable conditions to tumor establishment or favor tumor progression, thus linking obesity and colorectal cancer.

Anti-inflammatory Activity of Extra Virgin Olive Oil Polyphenols: Which Role in the Prevention and Treatment of Immune-Mediated Inflammatory Diseases?

BACKGROUND AND OBJECTIVE: Altered inflammatory response characterizes chronic immunemediated inflammatory diseases (IMID) such as rheumatoid arthritis, inflammatory bowel disease, multiple sclerosis, systemic lupus erythematosus, and psoriasis. Accumulating evidence indicates that regular consumption of extra virgin olive oil (EVOO), the main source of fat in the Mediterranean diet, is associated with a reduced risk of developing chronic degenerative disorders such as cardiovascular diseases, type 2 diabetes and cancer. The beneficial effects on health of EVOO have been attributed, besides to the monounsaturated fats content, to the presence of phenolic compounds that have antioxidant, anti-inflammatory and immunomodulatory properties. The purpose of this review is to provide an overview of the effects of EVOO polyphenols on IMID highlighting the potential mechanisms of action. METHODS: Scientific papers were found by searching in PubMed up to May 2017 using the following key words: rheumatoid arthritis, inflammatory bowel disease, multiple sclerosis, systemic lupus erythematosus, and psoriasis also in combination with EVOO, phenolic compounds, oleuropein, oleocantal, hydroxytyrosol,tyrosol and oleochantal. RESULTS: In vitro and in vivo studies indicate that EVOO and its polyphenols can improve diseases symptoms in IMID, by acting both at local and systemic levels and by modulating several molecular pathways. Nevertheless, there are not sufficient data to achieve specific nutritional guidelines. CONCLUSION: Further research is needed to evaluate the real contribution of EVOO and its phenolic compounds in modulating the IMID-associated inflammatory perturbations, in order to develop appropriate nutritional recommendations.

Recent Evidence on the Role of Dietary PUFAs in Cancer Development and Prevention.

BACKGROUND: Scientific evidence has been accumulated about the effects of polyunsaturated fatty acids (PUFAs) on human health. The hypothesis that n-3 PUFAs might improve the efficiency of anticancer drugs has recently been considered. The role of n-6 PUFAs, in contrast, needs to be better assessed. However, the effective mechanisms of action of PUFAs have not been fully clarified yet. This review aims to report the most updated evidence on the role of n-6 and n-3 PUFAs in the development and treatment of human cancers, focusing on the potential mechanisms by which PUFAs exert their effects. METHODS: We undertook a structured search in PubMed on February 17th 2017 for peer-reviewed research articles published from 2013. The search syntax used was: PUFA or PUFAs and cancer. RESULTS: Contradictory results were found, most likely due to the genetic background, the different dietary sources used, the interaction among different nutrients, and the tumor subtypes. However, the more recent findings strongly support the use of n-3 PUFAs in cancer prevention and treatment. On the other hand, n-6 PUFAs are often associated with an increased risk of cancer, even if recently their beneficial effects have also been highlighted. CONCLUSION: N-3 PUFAs may represent a potential therapeutic agent contributing to treat at least some type of human cancers. However, studies with larger sample sizes and longer follow-up times are still needed. To increase the knowledge about how food and nutrition can improve human health it is advisable to deliver an open access nutritional database.

Protocatechuic acid activates key components of insulin signaling pathway mimicking insulin activity.

SCOPE: Insulin resistance represents an independent risk factor for metabolic and cardiovascular diseases. Researchers have been interested in identifying active harmless compounds, as many insulin-sensitizing drugs have shown unwanted side-effects. It has been demonstrated that anthocyanins and one of their representative metabolites, protocatechuic acid (PCA), ameliorate hyperglycemia, and insulin sensitivity. This study investigated the mechanism of action of PCA responsible for the glucose uptake upregulation. METHODS AND RESULTS: In human visceral adipocytes, PCA stimulated insulin receptor substrate-1 (IRS-1) tyrosine phosphorylation (+40% with respect to untreated cells) and the downstream events, i.e. phosphoinositide 3-kinase binding to IRS-1 and Akt phosphorylation (+100%, +180%, respectively, with respect to untreated cells). The insulin-like activity of PCA seemed to be mediated by insulin receptor since by inhibiting its autophosphorylation, the PCA effects were completely abolished. Furthermore, PCA was able to activate adenosine monophosphate-activated protein kinase, a serine/threonine kinase whose activation elicits insulin-sensitizing effects. CONCLUSION: This study showed that PCA stimulates the insulin signaling pathway in human adipocytes increasing GLUT4 translocation and glucose uptake. Decreasing insulin resistance is a most desirable aim to be reached for an effective therapeutic/preventive action against metabolic syndrome and type 2 diabetes. Identifying specific food/food components able to improve glucose metabolism can offer an attractive, novel, and economical strategy.

ω3-PUFAs exert anti-inflammatory activity in visceral adipocytes from colorectal cancer patients.

OBJECTIVE: The aim of this study was to correlate specific fatty acid profiles of visceral white adipose tissue (WAT) with inflammatory signatures potentially associated with colorectal cancer (CRC). METHODS: Human adipocytes were isolated from biopsies of visceral WAT from 24 subjects subdivided in four groups: normal-weight (BMI 22.0-24.9 Kg/m2) and over-weight/obese (BMI 26.0-40.0 Kg/m2), affected or not by CRC. To define whether obesity and/or CRC affect the inflammatory status of WAT, the activation of the pro-inflammatory STAT3 and the anti-inflammatory PPARγ transcription factors as well as the expression of adiponectin were analyzed by immunoblotting in adipocytes isolated from each group of subjects. Furthermore, to evaluate whether differences in inflammatory WAT environment correlate with specific fatty acid profiles, gas-chromatographic analysis was carried out on WAT collected from all subject categories. Finally, the effect of the ω3 docosahexaenoic acid treatment on the balance between pro- and anti-inflammatory factors in adipocytes was also evaluated. RESULTS: We provide the first evidence for the existence of a pro-inflammatory environment in WAT of CRC patients, as assessed by the up-regulation of STAT3, and the concomitant decrease of PPARγ and adiponectin with respect to healthy subjects. WAT inflammatory status was independent of obesity degree but correlated with a decreased ω3-/ω6-polyunsaturated fatty acid ratio. These observations suggested that qualitative changes, other than quantitative ones, in WAT fatty acid may influence tissue dysfunctions potentially linked to inflammatory conditions. This hypothesis was further supported by the finding that adipocyte treatment with docosahexaenoic acid restored the equilibrium between STAT3 and PPARγ. CONCLUSION: Our results suggest that adipocyte dysfunctions occur in CRC patients creating a pro-inflammatory environment that might influence cancer development. Furthermore, the protective potential of docosahexaenoic acid in re-establishing the equilibrium between pro- and anti-inflammatory factors might represent a useful tool for preventive and therapeutic strategies.

Polyphenols, intracellular signalling and inflammation.

Excessive inflammation is considered as a critical factor in many human diseases, including cancer, obesity, type II diabetes, cardiovascular diseases, neurodegenerative diseases and aging. Compounds derived from botanic sources, such as phenolic compounds, have shown anti-inflammatory activity in vitro and in vivo. Recent data suggest that polyphenols can work as modifiers of signal transduction pathways to elicit their beneficial effects. These natural compounds express anti-inflammatory activity by modulation of pro-inflammatory gene expression such as cyclooxygenase, lipoxygenase, nitric oxide synthases and several pivotal cytokines, mainly by acting through nuclear factor-kappa B and mitogen-activated protein kinase signalling. This review will discuss recent data on the control of inflammatory signalling exerted by some dietary polyphenols contained in Mediterranean diet. A clear understanding of the molecular mechanisms of action of phenolic compounds is crucial in the valuation of these potent molecules as potential prophylactic and therapeutic agents.

Tyrosol, the major extra virgin olive oil compound, restored intracellular antioxidant defences in spite of its weak antioxidative effectiveness.

BACKGROUND AND AIM: Extra virgin olive oil has been associated with a reduced incidence of risk factors for coronary heart disease also owing to the presence of antioxidant biophenols. This study compared the protective effects of tyrosol and hydroxytyrosol, two biophenols greatly different in antioxidant power, on J774 A.1-mediated oxidation of LDL. METHODS AND RESULTS: Cell-mediated oxidation of LDL was evaluated by TBARS formation, and relative electrophoretic mobility increase. Redox imbalance was studied by: (i) cytofluorimetric determination of intracellular ROS and GSH, and (ii) evaluation of GSH-related enzyme activities and gene expressions by colorimetric and RT-PCR analyses, respectively. The cellular uptake of the biophenols was evaluated by HPLC. Both biophenols inhibited cell-mediated oxidation of LDL but to a different extent (100% hydroxytyrosol vs 40% tyrosol), and counteracted the impairment of antioxidant cellular defence, i.e., GSH and related enzymes. Tyrosol was effective in inhibiting about 30% of ROS production only at later time-points (12h for superoxide, 24h for hydrogen peroxides). Interestingly, both biophenols were effective when added to the cells for 2h and removed before LDL treatment. This was probably related to cell-biophenol interactions: hydroxytyrosol was rapidly found inside the cells (1.12+/-0.05ng/mg cell protein) and disappeared within 18h, while tyrosol accumulated intracellularly with time (0.68+/-0.09 vs 1.72+/-0.13ng/mg cell protein at minute 5 and hour 18, respectively). CONCLUSIONS: In spite of its weak antioxidant activity, tyrosol was effective in preserving cellular antioxidant defences, probably by intracellular accumulation. These findings give further evidence in favour of olive oil consumption to counteract cardiovascular diseases.

Extra virgin olive oil biophenols inhibit cell-mediated oxidation of LDL by increasing the mRNA transcription of glutathione-related enzymes.

It has been reported that oxidized LDL (oxLDL) are involved in the pathogenesis of atherosclerosis, and that macrophages as well as other cells of the arterial wall can oxidize LDL in vitro, depending on the balance between intracellular prooxidant generation and antioxidant defense efficiency. Because of their possible beneficial role in the prevention of atherosclerosis and other oxidative stress-associated diseases, phenolic compounds naturally occurring in vegetables, fruits, and beverages are receiving increased attention. In the present work, we investigated the mechanisms underlying the protective effect exerted by extra virgin olive oil biophenols, namely, protocatechuic acid and oleuropein, on LDL oxidation mediated by murine J774 A.1 macrophage-like cells. The biophenols were added to the cells with LDL and left in the medium during the entire experimental period, or for a period of 2 h and then removed from the medium before the addition of LDL. The effect of biophenols alone was also tested. In both experimental procedures, these antioxidants had the following effects: 1). completely prevented the J774 A.1-mediated oxidation of LDL; 2). counteracted the time-dependent variations in intracellular redox balance, inhibiting the production of O(2)(.-) and H(2)O(2) and the decrease in glutathione (GSH) content; 3). restored glutathione reductase (GR) and peroxidase (GPx) activities; and 4). restored the mRNA expression of gamma-glutamylcisteine synthetase (gammaGCS), GR, and GPx to control values. More importantly, we observed significant overtranscription and increased activities of two antioxidative enzymes, GPx and GR, compared with controls when the biophenols were present in the medium for 2 h and then removed before LDL exposure, or when the cells were exposed to the antioxidants alone for up to 24 h. Our findings suggest that the activation of mRNA transcription of GSH-related enzymes represents an important mechanism in phenolic antioxidative action.