Genes associated with metabolic syndrome predict disease-free survival in stage II colorectal cancer patients. A novel link between metabolic dysregulation and colorectal cancer

Studies have recently suggested that metabolic syndrome and its components increase the risk of colorectal cancer. Both diseases are increasing in most countries, and the genetic association between them has not been fully elucidated. The objective of this study was to assess the association between genetic risk factors of metabolic syndrome or related conditions (obesity, hyperlipidaemia, diabetes mellitus type 2) and clinical outcome in stage II colorectal cancer patients. Expression levels of several genes related to metabolic syndrome and associated alterations were analysed by real-time qPCR in two equivalent but independent sets of stage II colorectal cancer patients. Using logistic regression models and cross-validation analysis with all tumour samples, we developed a metabolic syndrome-related gene expression profile to predict clinical outcome in stage II colorectal cancer patients. The results showed that a gene expression profile constituted by genes previously related to metabolic syndrome was significantly associated with clinical outcome of stage II colorectal cancer patients. This metabolic profile was able to identify patients with a low risk and high risk of relapse. Its predictive value was validated using an independent set of stage II colorectal cancer patients. The identification of a set of genes related to metabolic syndrome that predict survival in intermediate-stage colorectal cancer patients allows delineation of a high-risk group that may benefit from adjuvant therapy and avoid the toxic and unnecessary chemotherapy in patients classified as low risk. Our results also confirm the linkage between metabolic disorder and colorectal cancer and suggest the potential for cancer prevention and/or treatment by targeting these genes.

Expression of microRNA-15b and the glycosyltransferase GCNT3 correlates with antitumor efficacy of Rosemary diterpenes in colon and pancreatic cancer

Colorectal and pancreatic cancers remain important contributors to cancer mortality burden and, therefore, new therapeutic approaches are urgently needed. Rosemary (Rosmarinus officinalis L.) extracts and its components have been reported as natural potent antiproliferative agents against cancer cells. However, to potentially apply rosemary as a complementary approach for cancer therapy, additional information regarding the most effective composition, its antitumor effect in vivo and its main molecular mediators is still needed. In this work, five carnosic acid-rich supercritical rosemary extracts with different chemical compositions have been assayed for their antitumor activity both in vivo (in nude mice) and in vitro against colon and pancreatic cancer cells. We found that the antitumor effect of carnosic acid together with carnosol was higher than the sum of their effects separately, which supports the use of the rosemary extract as a whole. In addition, gene and microRNA expression analyses have been performed to ascertain its antitumor mechanism, revealing that up-regulation of the metabolic-related gene GCNT3 and down-regulation of its potential epigenetic modulator miR-15b correlate with the antitumor effect of rosemary. Moreover, plasmatic miR-15b down-regulation was detected after in vivo treatment with rosemary. Our results support the use of carnosic acid-rich rosemary extract as a complementary approach in colon and pancreatic cancer and indicate that GCNT3 expression may be involved in its antitumor mechanism and that miR-15b might be used as a non-invasive biomarker to monitor rosemary anticancer effect.

Study on the 3-hydroxy-3-methyl-glutaryl CoA reductase inhibitory properties of Agaricus bisporus and extraction of bioactive fractions using pressurised solvent technologies

BACKGROUND

Agaricus bisporus mushrooms were able to lower cholesterol levels in hypercholesterolaemic rats and it was suggested that dietary fibre might inhibit cholesterol absorption. However, A. bisporus extracts were also able to inhibit the 3-hydroxy-3-methyl-glutaryl CoA reductase (HMGCR, the key enzyme in the cholesterol biosynthetic pathway) and this might also contribute to the observed lowering of cholesterol levels in serum.

RESULTS

The methanol-water extracts obtained from A. bisporus were able to inhibit up to 60% the HMGCR activity using an in vitro assay. The HMGCR inhibitory capacities depended on cultivation conditions, strains, etc. The potential inhibitors were not statins, they might be β-glucans able to scavenge the substrate and impair the enzymatic reaction. They were present during all mushroom developmental stages and similarly distributed through all the tissues including the parts discarded as a by-product. Accelerated solvent extractions using 1:1 ethanol-water as pressurised solvent (10.7 MPa, 25°C, five cycles of 5 min) were more effective in the extraction of the HMGCiR inhibitor(s) than supercritical fluid extractions (9 MPa, 40°C) using CO2 with 10% ethanol.

CONCLUSION

A mushroom cultivation and two extraction procedures were optimised to obtain fractions from A. bisporus with high HMGCR inhibitory activities to design novel ingredients for hypocholesterolaemic functional foodstuffs.

Acute and repeated dose (28 days) oral safety studies of ALIBIRD in rats

ALIBIRD, a test substance composed of oligosaccharides derived from lactulose, a hydrolysate of a whey protein concentrate, and a supercritical extract of rosemary (1:0.5:0.05), was prepared in the laboratory and evaluated for its safety as a multifunctional food additive. In oral toxicity studies (acute and 28 days repeated dose) using Wistar rats, ALIBIRD was administered in a single oral gavage dose of 2,000 mg/kg of body weight and resulted in no adverse events or mortality; a daily dose of 2,000 mg/kg of body weight for 28 days by gavage also resulted in no adverse effects or mortality. No abnormal clinical signs, behavioral changes, body weight changes, or changes in food and water consumption occurred in either study. There were no changes in hematological and serum chemistry values, organ weights, or gross or histological characteristics. Based on test results, it is concluded that ALIBIRD is well tolerated in rats at an acute and subchronic (28 days) dose of 2,000 mg/kg of body weight.

Antitumor effect of 5-fluorouracil is enhanced by rosemary extract in both drug sensitive and resistant colon cancer cells

5-Fluorouracil (5-FU) is the most used chemotherapeutic agent in colorectal cancer. However, resistance to this drug is relatively frequent, and new strategies to overcome it are urgently needed. The aim of this work was to determine the antitumor properties of a supercritical fluid rosemary extract (SFRE), alone and in combination with 5-FU, as a potential adjuvant therapy useful for colon cancer patients. This extract has been recognized as a healthy component by the European Food Safety Authority (EFSA). The effects of SFRE both alone and in combination with 5-FU were evaluated in different human colon cancer cells in terms of cell viability, cytotoxicity, and cell transformation. Additionally, colon cancer cells resistant to 5-FU were used to assay the effects of SFRE on drug resistance. Finally, qRT-PCR was performed to ascertain the mechanism by which SFRE potentiates the effect of 5-FU. Our results show that SFRE displays dose-dependent antitumor activities and exerts a synergistic effect in combination with 5-FU on colon cancer cells. Furthermore, SFRE sensitizes 5-FU-resistant cells to the therapeutic activity of this drug, constituting a beneficial agent against both 5-FU sensitive and resistant tumor cells. Gene expression analysis indicates that the enhancement of the effect of 5-FU by SFRE might be explained by the downregulation of TYMS and TK1, enzymes related to 5-FU resistance.

Phytosterols esterified with conjugated linoleic acid. In vitro intestinal digestion and interaction on cholesterol bioaccessibility

Intestinal in vitro digestion of phytosterols esterified with conjugated linoleic acid (PS-CLA) was performed to study (1) the potential bioaccessibility of the released bioactive-lipid products and (2) the interference with cholesterol bioaccessibility. Commercial food-grade PS ester (PS-C) was assayed as reference. Hydrolysis of PS-CLA by digestive enzymes was similar to that of PS-C (51 and 47%, respectively), most lipids products being mainly included in the bioaccessible fraction, namely, the micellar phase (MP). Control assays in the absence of PS esters showed most cholesterol solubilized within the MP, whereas a displacement of total cholesterol was caused from MP after digestion of PS esters (14 and 36% displacement for PS-CLA and PS-C, respectively), cholesterol being partially precipitated. Precipitated cholesterol was linearly related to a parallel precipitation of saturated-chain PS, mainly determined by sitosterol (R² = 0.936). The higher composition in sitosteryl esters of PS-C with respect to PS-CLA might explain their different effects on cholesterol. Therefore, besides being a lipid delivery form of PS similar to other commercial esterified PS, the PS-CLA might have the additional advantage of being a lipid delivery form of CLA. Moreover, PS-CLA might hinder the bioaccessibility of cholesterol. Furthermore, the qualitative/quantitative profile in esterified PS forms might determine the magnitude of cholesterol interaction.

Phospholipases in food industry: a review

Mammal, plant, and mainly microbial phospholipases are continuously being studied, experimented, and some of them are even commercially available at industrial scale for food industry. This is because the use of phospholipases in the production of specific foods leads to attractive advantages, such as yield improvement, energy saving, higher efficiency, improved properties, or better quality of the final product. Furthermore, biocatalysis approaches in the food industry are of current interest as non-pollutant and cleaner technologies. The present chapter reviews the most representative examples of the use of phospholipases in food industry, namely edible oils, dairy, and baking products, emulsifying agents, as well as the current trend to the development of novel molecular species of phospholipids with added-value characteristics.

Effects of Thyme Extract Oils (from Thymus vulgaris, Thymus zygis, and Thymus hyemalis) on Cytokine Production and Gene Expression of oxLDL-Stimulated THP-1-Macrophages

Properties of thyme extracts from three different species (Thymus vulgaris, Thymus zygis, and Thymus hyemalis) were examined. Two oil fractions from each species were obtained by CO(2) supercritical fluid extraction. Main compounds presented in the supercritical extracts of the three thyme varieties were 1,8 cineole, thymol, camphor, borneol, and carvacrol. As a cellular model of inflammation/atherogenesis, we use human macrophages derived from THP-1 monocytes and activated by oxidized LDLs. These cells were incubated with the thyme fraction oils, and the productions and gene expressions of the inflammatory mediators TNF-α, IL-1B, IL-6, and IL-10 were determined. Thyme extracts significantly reduced production and gene expression of the proinflammatory mediators TNF-α, IL-1B, and IL-6 and highly increased these parameters on the anti-inflammatory IL-10 cytokine. Changes on production and gene expressions were dose dependent and according to the thyme content of each species. Taken together, these results may suggest that thyme extracts could have anti-inflammatory effects.

Pressurized liquid extraction as an alternative process to obtain antiviral agents from the edible microalga Chlorella vulgaris

The antiviral properties of pressurized liquid extracts (PLE) (acetone, ethanol, and water) obtained from the edible microalga Chlorella vulgaris were evaluated against herpes simplex virus type 1 (HSV-1). None of the extracts tested showed extracellular direct virucidal activity against the virus, although a pretreatment of Vero cells with 75 microg/mL of water and ethanol extracts before virus addition inhibited 70% of the virus infection. Moreover, water and ethanol extracts were able to significantly inhibit the in vitro virus replication, showing IC(50%) values of 61.05 and 80.23 microg/mL respectively. To identify the type of compounds responsible for the antiviral activity found in the water extract, the polysaccharide fraction was isolated. This activity was found to correlate with polysaccharides, because the polysaccharide-rich fraction (46% concentrated) showed higher antiviral activity than the complete water extract. A concentration of 75 microg/mL of this fraction inhibited 90% virus infection when added as a pretreatment and showed an IC(50%) value of 33.93 microg/mL for intracellular virus replication. GC-MS characterization of the ethanol extract showed that the antiviral activity of this extract could be partially related with the presence of phytol, although other compounds could be involved in this activity.

In vitro study of the effect of diesterified alkoxyglycerols with conjugated linoleic acid on adipocyte inflammatory mediators

Background

Adipocytes contribute to inflammation and the innate immune response through expression of inflammatory mediators. High levels of these mediators have been related to chronic inflammation state and insulin resistance, cardiovascular diseases and diabetes type 2, among other disorders. 3-octadecylglycerol (batyl alcohol) has been described as an inflammatory agent, whereas Conjugated Linoleic Acid (CLA) is considered effective against obesity. In this study we examined the anti-inflammatory activity and mechanisms of modified alkoxyglycerols. Tumor necrosis factor (TNF-α) activated mature adipocytes were used as cellular model of inflammation. Secreted levels and gene expressions of some inflammatory mediators, such as the adipokines, interleukin (IL)-1β, IL-6 and IL-10; and the levels of leptin and adiponectin hormones were quantified in presence and absence of alkoxyglycerols and when human adipocyte cells were or not activated by TNF-α. The aim of this study is to describe the effects of nonesterified alkoxyglycerols, CLA and diesterified alkoxyglycerols with CLA (DEA-CLA) and check if they present beneficial properties using an in vitro model of some chronic diseases related to the inflammatory process, such as obesity, using human mature adipocytes activated with TNF-α.

Results

Our data suggest that DEA-CLA, product of the esterification between the CLA and batyl alcohol, present beneficial effects on adipocytes close to observed and described for CLA (i.e. decrease of IL-1β) and no adverse effects as observed for batyl alcohol (i.e. decrease of IL-10). In addition, DEA-CLA presented similar activity to CLA showing a trend to increase the secreted levels of adiponectin and decreasing the secreted levels of leptin.

Conclusions

CLA and DEA-CLA modify adipocyte inflammatory mediators and also could play a role on energy homeostasis through depletion of leptin levels.

Acute and repeated dose (28 days) oral safety studies of an alkoxyglycerol extract from shark liver oil in rats

Shark liver oil has been used for over 50 years as both a therapeutic and preventive agent. The active ingredients in shark liver oil have been found to be a group of ether-linked glycerols known as alkoxyglycerols. Despite its popularity, there is little published toxicology data on alkoxyglycerols. The toxicity of a supercritical fluid extract of shark liver oil (AKG-1 extract) has been evaluated in acute and repeated dose (28 days) oral toxicity studies in rats at doses of 200 and 100 times the maximum recommended dose by supplement manufacturers in humans, respectively. The AKG-1 extract administered in a single oral gavage dose of 2000 mg kg(-1) of body weight resulted in no adverse events or mortality. The AKG-1 extract administered as a daily dose of 1000 mg kg(-1) of body weight for 28 days by gavage resulted in no adverse effects or mortality. For both studies, no abnormal clinical signs, behavioral changes, body weight changes, or change in food and water consumption occurred. There were no changes in hematological and serum chemistry values, organ weights, or gross or histological characteristics. It is concluded that the AKG-1 extract is well tolerated in rats at an acute dose of 2000 mg kg(-1) and at a subchronic (28 days) dose of 1000 mg kg(-1).

Design of natural food antioxidant ingredients through a chemometric approach

In the present work, an environmentally friendly extraction process using subcritical conditions has been tested to obtain potential natural food ingredients from natural sources such as plants, fruits, spirulina, propolis, and tuber, with the scope of substituting synthetic antioxidants, which are subject to regulation restrictions and might be harmful for human health. A full characterization has been undertaken from the chemical and biochemical point of view to be able to understand their mechanism of action. Thus, an analytical method for profiling the compounds responsible for the antioxidant activity has been used, allowing the simultaneous determination of water-soluble vitamins, fat-soluble vitamins, phenolic compounds, carotenoids, and chlorophylls in a single run. This information has been integrated and analyzed using a chemometrical approach to correlate the bioactive compounds profile with the antioxidant activity and thus to be able to predict antioxidant activities of complex formulations. As a further step, a simplex centroid mixture design has been tested to find the optimal formulation and to calculate the effect of the interaction among individual extracts in the mixture.

Testing and enhancing the in vitro bioaccessibility and bioavailability of Rosmarinus officinalis extracts with a high level of antioxidant abietanes

An antioxidant-enriched extract (RE) was obtained from rosemary (Rosmarinus officinalis) by supercritical fluid extraction to be used as an ingredient to design functional foods. The optimized mixture (42 mg RE g(-1) sunflower oil) was submitted to in vitro digestion and absorption tests (using Caco2 cells) to investigate the effect of these processes on its DPPH scavenging activity and also whether its major abietanes (tricyclic diterpenes) might be bioaccessible and bioavailable. Results indicated that supplementation of the rosemary extract with sunflower oil and lecithin (37 mg g(-1)) enhanced abietanes micellation (almost 2-fold). In vitro digestion of the mixture including RE, sunflower oil, and lecithin reduced 50% the bioaccesibility in terms of antioxidant activity. Bioavailability was 31%. It was evidenced that this activity was not due to the original levels of carnosol, carnosic acid, and methyl carnosate (which only 47% remained after digestion) but due to their derivatives and digestion products.

Recent trends in the advanced analysis of bioactive fatty acids

The consumption of dietary fats have been long associated to chronic diseases such as obesity, diabetes, cancer, arthritis, asthma, and cardiovascular disease; although some controversy still exists in the role of dietary fats in human health, certain fats have demonstrated their positive effect in the modulation of abnormal fatty acid and eicosanoid metabolism, both of them associated to chronic diseases. Among the different fats, some fatty acids can be used as functional ingredients such as alpha-linolenic acid (ALA), arachidonic acid (AA), eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), gamma-linolenic acid (GLA), stearidonic acid (STA) and conjugated linoleic acid (CLA), among others. The present review is focused on recent developments in FAs analysis, covering sample preparation methods such as extraction, fractionation and derivatization as well as new advances in chromatographic methods such as GC and HPLC. Special attention is paid to trans fatty acids due its increasing interest for the food industry.