Silibinin is a suppressor of the metastasis-promoting transcription factor ID3.

BACKGROUND: ID3 (inhibitor of DNA binding/differentiation-3) is a transcription factor that enables metastasis by promoting stem cell-like properties in endothelial and tumor cells. The milk thistle flavonolignan silibinin is a phytochemical with anti-metastatic potential through largely unknown mechanisms. HYPOTHESIS/PURPOSE: We have mechanistically investigated the ability of silibinin to inhibit the aberrant activation of ID3 in brain endothelium and non-small cell lung cancer (NSCLC) models. METHODS: Bioinformatic analyses were performed to investigate the co-expression correlation between ID3 and bone morphogenic protein (BMP) ligands/BMP receptors (BMPRs) genes in NSCLC patient datasets. ID3 expression was assessed by immunoblotting and qRT-PCR. Luciferase reporter assays were used to evaluate the gene sequences targeted by silibinin to regulate ID3 transcription. In silico computational modeling and LanthaScreen TR-FRET kinase assays were used to characterize and validate the BMPR inhibitory activity of silibinin. Tumor tissues from NSCLC xenograft models treated with oral silibinin were used to evaluate the in vivo anti-ID3 effects of silibinin. RESULTS: Analysis of lung cancer patient datasets revealed a top-ranked positive association of ID3 with the BMP9 endothelial receptor ACVRL1/ALK1 and the BMP ligand BMP6. Silibinin treatment blocked the BMP9-induced activation of the ALK1-phospho-SMAD1/5-ID3 axis in brain endothelial cells. Constitutive, acquired, and adaptive expression of ID3 in NSCLC cells were all significantly downregulated in response to silibinin. Silibinin blocked ID3 transcription via BMP-responsive elements in ID3 gene enhancers. Silibinin inhibited the kinase activities of BMPRs in the micromolar range, with the lower IC50 values occurring against ACVRL1/ALK1 and BMPR2. In an in vivo NSCLC xenograft model, tumoral overexpression of ID3 was completely suppressed by systematically achievable oral doses of silibinin. CONCLUSIONS: ID3 is a largely undruggable metastasis-promoting transcription factor. Silibinin is a novel suppressor of ID3 that may be explored as a novel therapeutic approach to interfere with the metastatic dissemination capacity of NSCLC.

Evaluation of Bioactive Effects of Five Plant Extracts with Different Phenolic Compositions against Different Therapeutic Targets.

Plant extracts rich in phenolic compounds have been reported to exert different bioactive properties. Despite the fact that there are plant extracts with completely different phenolic compositions, many of them have been reported to have similar beneficial properties. Thus, the structure-bioactivity relationship mechanisms are not yet known in detail for specific classes of phenolic compounds. In this context, this work aims to demonstrate the relationship of extracts with different phenolic compositions versus different bioactive targets. For this purpose, five plant matrices (Theobroma cacao, Hibiscus sabdariffa, Silybum marianum, Lippia citriodora, and Olea europaea) were selected to cover different phenolic compositions, which were confirmed by the phytochemical characterization analysis performed by HPLC-ESI-qTOF-MS. The bioactive targets evaluated were the antioxidant potential, the free radical scavenging potential, and the inhibitory capacity of different enzymes involved in inflammatory processes, skin aging, and neuroprotection. The results showed that despite the different phenolic compositions of the five matrices, they all showed a bioactive positive effect in most of the evaluated assays. In particular, matrices with very different phenolic contents, such as T. cacao and S. marianum, exerted a similar inhibitory power in enzymes involved in inflammatory processes and skin aging. It should also be noted that H. sabdariffa and T. cacao extracts had a low phenolic content but nevertheless stood out for their bioactive antioxidant and anti-radical capacity. Hence, this research highlights the shared bioactive properties among phenolic compounds found in diverse matrices. The abundance of different phenolic compound families highlights their elevated bioactivity against diverse biological targets.

Plant-Derived Natural Products for the Treatment of Bacterial Infections.

Bacterial infections are a significant public health concern, and the emergence of antibiotic-resistant bacteria (ARB) has become a major challenge for modern medicine. The overuse and misuse of antibiotics have contributed to the development of ARB, which has led to the need for alternative therapies. Plant-derived natural products (PNPs) have been extensively studied for their potential as alternative therapies for the treatment of bacterial infections. The diverse chemical compounds found in plants have shown significant antibacterial properties, making them a promising source of novel antibacterial agents. The use of PNPs as antibacterial agents is particularly appealing because they offer a relatively safe and cost-effective approach to the treatment of bacterial infections. This chapter aims to provide an overview of the current state of research on PNPs as antibacterial agents. It will cover the mechanisms of action of the main PNPs against bacterial pathogens and discuss their potential to be used as complementary therapies to combat ARB. This chapter will also highlight the most common screening methodologies to discover new PNPs and the challenges and future prospects in the development of these compounds as antibacterial agents.

Artificial Intelligence Applied to Improve Scientific Reviews: The Antibacterial Activity of Cistus Plants as Proof of Concept.

Reviews have traditionally been based on extensive searches of the available bibliography on the topic of interest. However, this approach is frequently influenced by the authors' background, leading to possible selection bias. Artificial intelligence applied to natural language processing (NLP) is a powerful tool that can be used for systematic reviews by speeding up the process and providing more objective results, but its use in scientific literature reviews is still scarce. This manuscript addresses this challenge by developing a reproducible tool that can be used to develop objective reviews on almost every topic. This tool has been used to review the antibacterial activity of Cistus genus plant extracts as proof of concept, providing a comprehensive and objective state of the art on this topic based on the analysis of 1601 research manuscripts and 136 patents. Data were processed using a publicly available Jupyter Notebook in Google Collaboratory here. NLP, when applied to the study of antibacterial activity of Cistus plants, is able to recover the main scientific manuscripts and patents related to the topic, avoiding any biases. The NLP-assisted literature review reveals that C. creticus and C. monspeliensis are the first and second most studied Cistus species respectively. Leaves and fruits are the most commonly used plant parts and methanol, followed by butanol and water, the most widely used solvents to prepare plant extracts. Furthermore, Staphylococcus. aureus followed by Bacillus. cereus are the most studied bacterial species, which are also the most susceptible bacteria in all studied assays. This new tool aims to change the actual paradigm of the review of scientific literature to make the process more efficient, reliable, and reproducible, according to Open Science standards.

Influence of Drying Temperature and Harvesting Season on Phenolic Content and Antioxidant and Antiproliferative Activities of Olive (Olea europaea) Leaf Extracts.

Interest in plant compounds has increased, given recent evidence regarding their role in human health due to their pleiotropic effects. For example, plant bioactive compounds present in food products, including polyphenols, are associated with preventive effects in various diseases, such as cancer or inflammation. Breast and colorectal cancers are among the most commonly diagnosed cancers globally. Although appreciable advances have been made in treatments, new therapeutic approaches are still needed. Thus, in this study, up to 28 olive leaf extracts were obtained during different seasons and using different drying temperatures. The influence of these conditions on total polyphenolic content (measured using Folin-Ciocalteu assays), antioxidant activity (using Trolox Equivalent Antioxidant Capacity and Ferric Reducing Ability of Plasma assays) and antiproliferative capacity (using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, MTT assays) was tested in breast and colorectal cancer cells. Increased phenolic composition and antioxidant and antiproliferative capacity are noted in the extracts obtained from leaves harvested in autumn, followed by summer, spring and winter. Regarding drying conditions, although there is not a general trend, conditions using the highest temperatures lead to the optimal phenolic content and antioxidant and antiproliferative activities in most cases. These results confirm previously published studies and provide evidence in support of the influence of both harvesting and drying conditions on the biological activity of olive leaf extracts.

The antimicrobial capacity of Cistus salviifolius and Punica granatum plant extracts against clinical pathogens is related to their polyphenolic composition.

Antimicrobial resistance poses a serious threat to human health worldwide. Plant compounds may help to overcome antibiotic resistance due to their potential resistance modifying capacity. Several botanical extracts and pure polyphenolic compounds were screened against a panel of eleven bacterial isolates with clinical relevance. The two best performing agents, Cistus salviifolius (CS) and Punica granatum (GP) extracts, were tested against 100 Staphylococcus aureus clinical isolates, which resulted in average MIC50 values ranging between 50-80 µg/mL. CS extract, containing hydrolyzable tannins and flavonoids such as myricetin and quercetin derivatives, demonstrated higher activity against methicillin-resistant S. aureus isolates. GP extract, which contained mostly hydrolyzable tannins, such as punicalin and punicalagin, was more effective against methicillin-sensitive S. aureus isolates. Generalized linear model regression and multiple correspondence statistical analysis revealed a correlation between a higher susceptibility to CS extract with bacterial resistance to beta-lactam antibiotics and quinolones. On the contrary, susceptibility to GP extract was related with bacteria sensitive to quinolones and oxacillin. Bacterial susceptibility to GP and CS extracts was linked to a resistance profile based on cell wall disruption mechanism. In conclusion, a differential antibacterial activity against S. aureus isolates was observed depending on antibiotic resistance profile of isolates and extract polyphenolic composition, which may lead to development of combinatorial therapies including antibiotics and botanical extracts.

Antioxidant Supplementation Modulates Neutrophil Inflammatory Response to Exercise-Induced Stress.

The aim of the present report was to evaluate the inflammatory response to a 2000-m running test considering neutrophil myeloperoxidase as an inflammatory marker, and to verify if supplements rich in antioxidants could modulate Post-test antioxidant and anti-inflammatory responses. To this end, a 21-day homogenization period was carried out with three groups: a control group, a supplemented group taking an almond beverage enriched with vitamins C and E and a third group consuming the same beverage but enriched with Lippia citriodora extract. At the end of this period, participants performed a 2000-m run, and blood samples were obtained the day before and immediately after the running test. Plasma and neutrophils were isolated. As a result, plasma creatine kinase and myoglobin increased, indicating Post-test muscle damage. Plasma oxidative markers were increased in all groups, except in the group supplemented with the almond beverage. Neutrophil antioxidant enzymes were significantly increased only in the control group, suggesting an antioxidant effect of the supplements provided in the other groups. Myeloperoxidase activity was significantly increased after the test in the control group, while increased enzyme levels were detected in plasma of the supplement groups. Therefore, antioxidant consumption seems to favour myeloperoxidase release. The connection of this observation with post-exercise recovery will require further investigation.

Quercetin metabolites from Hibiscus sabdariffa contribute to alleviate glucolipotoxicity-induced metabolic stress in vitro.

Polyphenols from Hibiscus sabdariffa (HS) alleviate obesity-related metabolic complications but the metabolites responsible for such effects are unknown. We aimed to elucidate which of the potential plasma metabolites from a polyphenol-enriched HS (PEHS) extract contributed for the reversion of glucolipotoxicity-induced metabolic stress using 3T3-L1 adipocyte and INS 832/13 pancreatic ß-cell models under glucolipotoxic conditions. PEHS extract, quercetin (Q) and quercetin-3-O-glucuronide (Q3GA) showed stronger capacity to decrease glucolipotoxicity-induced ROS generation than ascorbic acid or chlorogenic acid. PEHS extract, Q and Q3GA decreased secretion of cytokines (leptin, TNF-α, IGF-1, IL-6, VEGF, IL-1α, IL-1ß and CCL2) and reduced CCL2 expression at transcriptional level. In addition, PEHS extract, Q and Q3GA reduced triglyceride accumulation, which occurred through fatty acid synthase (FASN) downregulation, AMPK activation and mitochondrial mass and biogenesis restoration via PPARα upregulation. Electron microscopy confirmed that PEHS extract and Q3GA decreased mitochondrial remodeling and mitophagy. Virtual screening leads us to postulate that Q and Q3GA might act as agonists of these protein targets at specific sites. These data suggest that Q and Q3GA may be the main responsible compounds for the capacity of PEHS extract to revert glucolipotoxicity-induced metabolic stress through AMPK-mediated decrease in fat storage and increase in fatty acid oxidation, though other compounds of the extract may contribute to this capacity.

The Beneficial Effects of Lippia Citriodora Extract on Diet-Induced Obesity in Mice Are Associated with Modulation in the Gut Microbiota Composition.

SCOPE: Obesity is characterized by a dysfunction in the adipose tissue and an inflammatory subclinical state leading to insulin resistance and increased risk of cardiovascular diseases. It is also associated with intestinal dysbiosis that contributes to inflammation development. Lippia citriodora (LCE) contains high levels of polyphenolpropanoids and has shown promising results in obesity. The aim of this study is to investigate a well-characterized extract of LCE in a model of metabolic syndrome in mice, focusing on its effects on metabolic tissues, endothelial dysfunction, and microbiome. METHODS: Mice are fed a high fat diet (HFD) for six weeks and treated daily with LCE (1, 10, and 25 mg kg-1 ). Glucose and lipid metabolism is investigated. The inflammatory state in the metabolic tissues and the intestinal microbiota composition are characterized, as well as the endothelium-dependent vasodilator response to acetylcholine. RESULTS: LCE reduces fat accumulation and improves plasma glycemic and lipid profiles, as well as the inflammatory process and vascular dysfunction. Moreover, LCE lessens intestinal dysbiosis, as it reduces the Firmicutes/Bacteroidetes ratio and increases Akkermansia abundance in comparison with untreated HFD mice. CONCLUSION: The antiobesity therapeutic properties of LCE are most probably mediated by the synergic effects of its bioactive compounds.

Antimicrobial Capacity of Plant Polyphenols against Gram-positive Bacteria: A Comprehensive Review.

BACKGROUND: Multi-drug-resistant bacteria such as Methicillin-Resistant Staphylococcus aureus (MRSA) disseminate rapidly amongst patients in healthcare facilities and suppose an increasingly important cause of community-associated infections and associated mortality. The development of effective therapeutic options against resistant bacteria is a public health priority. Plant polyphenols are structurally diverse compounds that have been used for centuries for medicinal purposes, including infections treatment and possess, not only antimicrobial activity, but also antioxidant, anti-inflammatory and anticancer activities among others. Based on the existing evidence on the polyphenols' antibacterial capacity, polyphenols may be postulated as an alternative or complementary therapy for infectious diseases. OBJECTIVE: To review the antimicrobial activity of plant polyphenols against Gram-positive bacteria, especially against S. aureus and its resistant strains. Determine the main bacterial molecular targets of polyphenols and their potential mechanism of action. METHODOLOGY: The most relevant reports on plant polyphenols' antibacterial activity and their putative molecular targets were studied. We also performed virtual screening of thousand different polyphenols against proteins involved in the peptidoglycan biosynthesis to find potential valuable bioactive compounds. The bibliographic information used in this review was obtained from MEDLINE via PubMed. RESULTS: Several polyphenols: phenolic acids, flavonoids (especially flavonols), tannins, lignans, stilbenes and combinations of these in botanical mixtures, have exhibited significant antibacterial activity against resistant and non-resistant Gram-positive bacteria at low µg/mL range MIC values. Their mechanism of action is quite diverse, targeting cell wall, lipid membrane, membrane receptors and ion channels, bacteria metabolites and biofilm formation. Synergic effects were also demonstrated for some combinations of polyphenols and antibiotics. CONCLUSION: Plant polyphenols mean a promising source of antibacterial agents, either alone or in combination with existing antibiotics, for the development of new antibiotic therapies.

The prebiotic properties of Hibiscus sabdariffa extract contribute to the beneficial effects in diet-induced obesity in mice.

The metabolic syndrome has been associated with an alteration of intestinal microbiota, which can be considered as a target for the management of these patients. Phenolic extracts from Hibiscus sabdariffa have shown beneficial effects on obesity and its related complications. However, their effects on gut microbiota have not been investigated yet. This study evaluates the effects of a chemically characterized polyphenolic extract of H. sabdariffa (HSE) in an experimental model of diet-induced obesity (DIO) in mice. HSE was administered daily by oral gave for 42 days. HSE reduced weight increase in high fat diet (HFD)-fed mice, and improved glucose tolerance, insulin sensitivity and normalized LDL/HDL cholesterol ratio. It also enhanced the inflammatory state in the liver, reducing the expression of different adipokines and proinflammatory mediators, and reinforced gut integrity by increasing the expression of mucins and proteins involved in the maintenance of mucosal barrier. Moreover, HSE had a prebiotic effect, ameliorating the changes in the gut microbiota induced by the HFD. Thus, HSE improved the Firmicutes/Bacteroidetes ratio, which may contribute to the beneficial effects. Consequently, HSE could be considered for the development of a complementary treatment for the metabolic syndrome due to its beneficial properties.

Preclinical Evaluation of the Antimicrobial-Immunomodulatory Dual Action of Xenohormetic Molecules against Haemophilus influenzae Respiratory Infection.

Chronic obstructive pulmonary disease (COPD) is characterized by abnormal inflammation and impaired airway immunity, providing an opportunistic platform for nontypeable Haemophilus influenzae (NTHi) infection. In this context, therapies targeting not only overactive inflammation without significant adverse effects, but also infection are of interest. Increasing evidence suggests that polyphenols, plant secondary metabolites with anti-inflammatory and antimicrobial properties, may be protective. Here, a Cistus salviifolius plant extract containing quercetin, myricetin, and punicalagin was shown to reduce NTHi viability. Analysis of these polyphenols revealed that quercetin has a bactericidal effect on NTHi, does not display synergies, and that bacteria do not seem to develop resistance. Moreover, quercetin lowered NTHi airway epithelial invasion through a mechanism likely involving inhibition of Akt phosphorylation, and reduced the expression of bacterially-induced proinflammatory markers il-8, cxcl-1, il-6, pde4b, and tnfα. We further tested quercetin's effect on NTHi murine pulmonary infection, showing a moderate reduction in bacterial counts and significantly reduced expression of proinflammatory genes, compared to untreated mice. Quercetin administration during NTHi infection on a zebrafish septicemia infection model system showed a bacterial clearing effect without signs of host toxicity. In conclusion, this study highlights the therapeutic potential of the xenohormetic molecule quercetin against NTHi infection.

The metabolic and vascular protective effects of olive (Olea europaea L.) leaf extract in diet-induced obesity in mice are related to the amelioration of gut microbiota dysbiosis and to its immunomodulatory properties.

INTRODUCTION: Many studies have showed the beneficial effects of the olive (Olea europaea) leaf extract (OLE) in experimental models of metabolic syndrome, which have been ascribed to the presence of phenolic compounds, like oleuropeoside. This study evaluated the effects of a chemically characterized OLE in high fat diet (HFD)-induced obesity in mice, describing the underlying mechanisms involved in the beneficial effects, with special attention to vascular dysfunction and gut microbiota composition. METHODS: C57BL/6J mice were distributed in different groups: control, control-treated, obese and obese-treated with OLE (1, 10 and 25 mg/kg/day). Control mice received a standard diet, whereas obese mice were fed HFD. The treatment was followed for 5 weeks, and animal body weight periodically assessed. At the end of the treatment, metabolic plasma analysis (including lipid profile) as well as glucose and insulin levels were performed. The HFD-induced inflammatory status was studied in liver and fat, by determining the RNA expression of different inflammatory mediators by qPCR; also, different markers of intestinal epithelial barrier function were determined in colonic tissue by qPCR. Additionally, flow cytometry of immune cells from adipose tissue, endothelial dysfunction in aortic rings as well as gut microbiota composition were evaluated. Faecal microbiota transplantation (FMT) to antibiotic-treated mice fed with HFD was performed. RESULTS: OLE administration reduced body weight gain, basal glycaemia and insulin resistance, and showed improvement in plasma lipid profile when compared with HFD-fed mice. The extract significantly ameliorated the HFD-induced altered expression of key adipogenic genes, like PPARs, adiponectin and leptin receptor, in adipose tissue. Furthermore, the extract reduced the RNA expression of Tnf-α, Il-1ß, Il-6 in liver and adipose tissue, thus improving the tissue inflammatory status associated to obesity. The flow cytometry analysis in adipose tissue corroborated these observations. Additionally, the characterization of the colonic microbiota by sequencing showed that OLE administration was able to counteract the dysbiosis associated to obesity. The extract reversed the endothelial dysfunction observed in the aortic rings of obese mice. FMT from donors HFD-OLE to recipient mice fed an HFD prevented the development of obesity, glucose intolerance, insulin resistance and endothelial dysfunction. CONCLUSION: OLE exerts beneficial effects in HFD-induced obesity in mice, which was associated to an improvement in plasma and tissue metabolic profile, inflammatory status, gut microbiota composition and vascular dysfunction.

Intestinal Permeability Study of Clinically Relevant Formulations of Silibinin in Caco-2 Cell Monolayers.

An ever-growing number of preclinical studies have investigated the tumoricidal activity of the milk thistle flavonolignan silibinin. The clinical value of silibinin as a bona fide anti-cancer therapy, however, remains uncertain with respect to its bioavailability and blood⁻brain barrier (BBB) permeability. To shed some light on the absorption and bioavailability of silibinin, we utilized the Caco-2 cell monolayer model of human intestinal absorption to evaluate the permeation properties of three different formulations of silibinin: silibinin-meglumine, a water-soluble form of silibinin complexed with the amino-sugar meglumine; silibinin-phosphatidylcholine, the phytolipid delivery system Siliphos; and Eurosil85/Euromed, a milk thistle extract that is the active component of the nutraceutical Legasil with enhanced bioavailability. Our approach predicted differential mechanisms of transport and blood⁻brain barrier permeabilities between the silibinin formulations tested. Our assessment might provide valuable information about an idoneous silibinin formulation capable of reaching target cancer tissues and accounting for the observed clinical effects of silibinin, including a recently reported meaningful central nervous system activity against brain metastases.

Differential effects of a combination of Hibiscus sabdariffa and Lippia citriodora polyphenols in overweight/obese subjects: A randomized controlled trial.

Plant-polyphenols have shown the capacity to ameliorate obesity-induced metabolic disturbances, both in cell and animal models, where most therapeutic approaches have failed. On the basis of previous research, a dietary supplement containing 500 mg of a combination of polyphenolic extracts from Lippia citriodora L. and Hibiscus sabdariffa L. (LC-HS), in the context of an equilibrated isocaloric diet, was evaluated in a double blind, placebo-controlled and randomized trial in 56 obese/overweight subjects for two months. Compared to controls, the consumption of the LC-HS polyphenols showed significant improvements in body weight, abdominal circumference of overweight subjects (-6.79 ± 0.80 cm in overweight LC-HS group vs -1.85 ± 0.83 cm in controls, p < 0.001) and body fat % (-1.33 ± 0.15% in overweight LC-HS group vs -0.66 ± 0.17% in controls, p < 0.05). Heart rate and systolic blood pressure also presented significant improvements in overweight LC-HS participants. However, changes were more modest in obese subjects. Further, LC-HS extract significantly reduced lipid content and increased AMPK activity in a hypertrophied adipocyte cell model. Therefore, consumption of 500 mg/day of LC-HS extracts enriched in polyphenols for two months in the context of an isocaloric diet by overweight subjects decreased symptoms associated to obesity-related diseases. Modulation of fat metabolism in adipose tissue, probably mediated by AMPK activation, is proposed as a molecular target to be explored in future research.

Different behavior of polyphenols in energy metabolism of lipopolysaccharide-stimulated cells.

Energy metabolism is one of the main sources of reactive oxygen species leading to oxidation and inflammation in pathophysiological processes. Lipopolysaccharide (LPS)-activated mouse embryonic fibroblast (MEF) cell lines from knock-out mice for paraoxonase-1 and from transgenic mice overexpressing monocyte chemoattractant protein-1 were obtained as model of pro-oxidant and pro-inflammatory scenarios. Theobroma cacao and Lippia citriodora (worldwide consumed and common ingredient of many food products) were tested in these cell models to assess the action of polyphenols in the energy management. Our metabolomics experiments show a different behavior of polyphenols: T. cacao extract partially reverts the effect of LPS in a pro-oxidant scenario through the antioxidant properties of theobromine, flavonols and procyanidins, while L. citriodora seems to act mainly in a pro-inflammatory cell model through the action of verbascoside decreasing the production of pro-inflammatory cytokines and MCP-1. Nevertheless, the action of polyphenols cannot be attributed only to a mechanism of action but the sum of different modulations in biological pathways. The capacity of both plant extracts to decrease α-ketoglutarate levels merits special attention due to the implications in future medicine. The action of polyphenols modulating oxidative stress, cytokine production and epigenetic changes make an interesting source of bioactive compounds for nutraceutical or functional food purposes.

Rosemary (Rosmarinus officinalis) extract causes ROS-induced necrotic cell death and inhibits tumor growth in vivo.

Colorectal cancer is the third most common diagnosed cancer globally. Although substantial advances have been obtained both in treatment and survival rates, there is still a need for new therapeutical approaches. Natural compounds are a realistic source of new bioactive compounds with anticancer activity. Among them, rosemary polyphenols have shown a vast antiproliferative capacity against colon cancer cells in vitro and in animal models. We have investigated the antitumor activity of a rosemary extract (RE) obtained by using supercritical fluid extraction through its capacity to inhibit various signatures of cancer progression and metastasis such as proliferation, migration, invasion and clonogenic survival. RE strongly inhibited proliferation, migration and colony formation of colon cancer cells regardless their phenotype. Treatment with RE led to a sharp increase of intracellular ROS that resulted in necrosis cell death. Nrf2 gene silencing increased RE cytotoxic effects, thus suggesting that this pathway was involved in cell survival. These in vitro results were in line with a reduction of tumor growth by oral administration of RE in a xenograft model of colon cancer cells using athymic nude mice. These findings indicate that targeting colon cancer cells by increasing intracellular ROS and decreasing cell survival mechanisms may suppose a therapeutic option in colon cancer through the combination of rosemary compounds and chemotherapeutic drugs.

Anthocyanic pigments from elicited in vitro grown shoot cultures of Vaccinium corymbosum L., cv. Brigitta Blue, as photosensitizer in natural dye-sensitized solar cells (NDSSC).

We investigated the effect on anthocyanins and total phenols content and antioxidant capacity of in vitro shoot cultures of Vaccinium corymbosum L., cv. Brigitta Blue, grown on an eliciting medium supplied with 10 µM naphthalene acetic acid, in combination with reduced content of salts and organics in respect to the basal medium. After 45 days, higher content of total phenols and anthocyanins was obtained from extracts of shoots grown on the elicitation medium. Anthocyanin molecules, absent in control shoots, were identified by HPLC-MS as delphinidine-glycoside, cyanidine-glycoside, delphinidine-arabinoside, cyanidine- arabinoside and cyanidine-acetylglycoside. Chlorogenic acid, present in control shoots, was nearly absent in elicited shoots. We exploited the anthocyanin - based raw extracts of "Brigitta Blue" shoots grown on the elicitation medium as a source of natural dye photosensitizers for Dye Sensitized Solar Cells, taking into account that such raw extracts showed antioxidant properties and photostability features. A purified dye was also prepared and the comparison of the latter with the raw one has been analysed by spectrophotometric, chromatographic and power conversion efficiency determination. The power conversion efficiencies from the raw and the purified dye were not different and they were comparable to the data obtained by other authors with anthocyanin-based dyes from in vivo grown plants.

Hibiscus and lemon verbena polyphenols modulate appetite-related biomarkers in overweight subjects: a randomized controlled trial.

TRIAL DESIGN: Plant-derived polyphenols have shown potential to alleviate obesity-related pathologies by a multi-targeted mechanism in animal models and human intervention studies. A dietary supplement based on a combination of Lippia citriodora (LC) and Hibiscus sabdariffa (HS) polyphenolic extracts was assayed in a double blind and placebo-controlled intervention study with 54 overweight subjects. METHODS: Blood pressure, body weight, height, triceps, biceps and abdominal skinfold thickness, and arm and abdominal circumferences were taken at the baseline, 30 and 60 days of the intervention period. The validated Visual Analogue Scale used to record hunger and satiety-related sensations was passed at the beginning and at 15, 30, 45 and 60 days of the intervention. Subjective health status was assessed through the validated SF-36 questionnaire at the beginning and end of the study. Finally, plasma from fasting blood samples was obtained at the beginning, 30 and 60 days of the study. RESULTS: The results showed an improvement of anthropometric measurements, decreased blood pressure and heart rate and a more positive perception in the overall health status. We also observed that plant polyphenols increased anorexigenic hormones (glucagon-like peptide-1) and decreased orexigenic hormones (ghrelin). CONCLUSIONS: Based on previous evidence we postulate that AMP-activated protein kinase may have a role in such effects through its capability to modulate energy homeostasis, total daily energy expenditure and lipid management. Although further research may be required, we propose that this polyphenolic combination may be used for weight management by increasing long-term weight loss maintenance through the modulation of appetite biomarkers. This may help to avoid the undesired weight regain typical of calorie restriction diets.