Phenolic-rich extracts from avocado fruit residues as functional food ingredients with antioxidant and antiproliferative properties

In this study, the total phenolic compounds content and profile, the nutritional value, the antioxidant and antiproliferative activities of avocado peel, seed coat, and seed extracts were characterized. Additionally, an in-silico analysis was performed to identify the phenolic compounds with the highest intestinal absorption and Caco-2 permeability. The avocado peel extract possessed the highest content of phenolic compounds (309.95 ± 25.33 mMol GA/100 g of extract) and the lowest effective concentration (EC50) against DPPH and ABTS radicals (72.64 ± 10.70 and 181.68 ± 18.47, respectively). On the other hand, the peel and seed coat extracts had the lowest energy densities (226.06 ± 0.06 kcal/100g and 219.62 ± 0.49 kcal/100g, respectively). Regarding the antiproliferative activity, the avocado peel extract (180 ± 40 µg/mL) showed the lowest inhibitory concentration (IC50), followed by the seed (200 ± 21 µg/mL) and seed coat (340 ± 32 µg/mL) extracts. The IC50 of the extracts induced apoptosis in Caco-2 cells at the early and late stages. According to the in-silico analysis, these results could be related to the higher Caco-2 permeability to hy-droxysalidroside, salidroside, sakuranetin, and luteolin. Therefore, this study provides new insights regarding the potential use of these extracts as functional ingredients with antioxidant and antiproliferative properties and as medicinal agents in diseases related to oxidative stress such as cancer. © 2021 by the authors. Licensee MDPI, Basel, Switzerland

Phenolic composition of artichoke waste and its antioxidant capacity on differentiated Caco-2 cells

Artichoke waste represents a huge amount of discarded material. This study presents the by-products (bracts, exterior leaves, and stalks) of the “Blanca de Tudela” artichoke variety as a potential source of phenolic compounds with promising antioxidant properties. Artichoke residues were subjected to different extraction processes, and the antioxidant capacity and phenolic composition of the extracts were analyzed by spectrophotometric methods and high performance liquid chromatography (HPLC) analyses, respectively. The most abundant polyphenols in artichoke waste were chlorogenic acid, luteolin-7-O-rutinoside, and luteolin-7-O-glucoside. Minor quantities of cynarin, luteolin, apigenin-7-O-glucoside, apigenin-7-O-rutinoside, and naringenin-7-O-glucoside were also found. The antioxidant activity of the obtained extracts determined by ABTS [2, 2’-azinobis (3-ethylbenzothiazoline-6-sulphonic acid)], DPPH (2, 2-diphenyl-1-pycrilhydracyl), and FRAP (Ferric Ion Reducing Antioxidant Power) was highly correlated with the total concentration of phenolic compounds. Chlorogenic acid, luteolin-7-O-glucoside, and luteolin-7-O-rutinoside, the most abundant compounds in 60% methanol extracts, are the components most responsible for the antioxidant activity of the artichoke waste extracts. The extract with the best antioxidant capacity was selected to assay its antioxidant potential on a model intestinal barrier. This action of the hydroxycinnamic acids on intestinal cells (Caco-2) was confirmed. In summary, artichoke waste may be considered a very interesting ingredient for food functionalization and for therapeutic purposes

Grape stem extracts with potential anticancer and antioxidant properties

The application of plant extracts for therapeutic purposes has been used in traditional medicine because plants contain bioactive compounds with beneficial properties for health. Currently, the use of these compounds that are rich in polyphenols for the treatment and prevention of diseases such as cancer, diabetes, and cardiovascular diseases, many of them related to oxidative stress, is gaining certain relevance. Polyphenols have been shown to have antimutagenic, antioxidant, and anti-inflammatory properties. Therefore, the objective of the present work was to study the potential effect of grape stem extracts (GSE), rich in phenolic compounds, in the treatment of cancer, as well as their role in the prevention of this disease associated with its antioxidant power. For that purpose, three cancer lines (Caco-2, MCF-7, and MDA-MB-231) were used, and the results showed that grape stem extracts were capable of showing an antiproliferative effect in these cells through apoptosis cell death associated with a modification of the mitochondrial potential and reactive oxygen species (ROS) levels. Additionally, grape stem extracts showed an antioxidant effect on differentiated intestinal cells that could protect the intestine from diseases related to oxidative stress. Therefore, grape extracts contain bioactive principles with important biological properties and could be used as bio-functional food ingredients to prevent diseases or even to improve certain aspects of human health

Protein hydrolysates from fenugreek (Trigonella foenum graecum) as nutraceutical molecules in colon cancer treatment

The application of plant extracts for therapeutic purposes has been used in traditional medicine since the plants are a source of a great variety of chemical compounds that possess biological activity. Actually, the effect of these extracts on diseases such as cancer is being widely studied. Colorectal adenocarcinoma is one of the main causes of cancer related to death and the second most prevalent carcinoma in Western countries. The aim of this work is to study the possible effect of two fenugreek (Trigonella foenum graecum) protein hydrolysates on treatment and progression of colorectal cancer. Fenugreek proteins from seeds were hydrolysed by using two enzymes separately, which are named Purafect and Esperase, and were then tested on differentiated and undifferentiated human colonic adenocarcinoma Caco2/TC7 cells. Both hydrolysates did not affect the growth of differentiated cells, while they caused a decrease in undifferentiated cell proliferation by early apoptosis and cell cycle arrest in phase G1. This was triggered by a mitochondrial membrane permeabilization, cytochrome C release to cytoplasm, and caspase-3 activation. In addition, the hydrolysates of fenugreek proteins displayed antioxidant activity since they reduce the intracellular levels of ROS. These findings suggest that fenugreek protein hydrolysates could be used as nutraceutical molecules in colorectal cancer treatment

Influence of Extraction Solvent on the Biological Properties of Maritime Pine Bark (Pinus pinaster)

Maritime pine bark (Pinus pinaster Aiton subsp. atlantica) is rich in polyphenols with known bioactive properties which are beneficial for human health. However, biological activities of bark extracts depend on the type of polyphenols extracted and the characteristics of these extractives depend on several factors such as the type of solvents used. The in uence of the extraction solvent on the composition and consequently on the properties of the extracts has been poorly described. Thus, in this study the in uence of the extraction solvent (water, ethanol and ethanol-water (50/50 v/v%)) on the antibacterial and anticancer properties of P. pinaster bark samples were evaluated. LC-DAD-MS profiling of the different extracts was also carried out to study their polyphenol composition. Results show that extraction solvent must be carefully chosen with respect to foreseeing use of bark extracts, since ethanolic and hydroethanolic extracts displayed the greatest antibacterial activity whereas water extracts showed increased anticancer properties. © 2022. International Journal of Food Studies.All Rights Reserve

Hepatic subcellular distribution of squalene changes according to the experimental setting

Squalene is the main unsaponifiable component of virgin olive oil, the main source of dietary fat in Mediterranean diet, traditionally associated with a less frequency of cardiovascular diseases. In this study, two experimental approaches were used. In the first, New Zealand rabbits fed for 4 weeks with a chow diet enriched in 1% sunflower oil for the control group, and in 1% of sunflower oil and 0.5% squalene for the squalene group. In the second, APOE KO mice received either Western diet or Western diet enriched in 0.5% squalene for 11 weeks. In both studies, liver samples were obtained and analyzed for their squalene content by gas chromatography-mass spectrometry. Hepatic distribution of squalene was also characterized in isolated subcellular organelles. Our results show that dietary squalene accumulates in the liver and a differential distribution according to studied model. In this regard, rabbits accumulated in cytoplasm within small size vesicles, whose size was not big enough to be considered lipid droplets, rough endoplasmic reticulum, and nuclear and plasma membranes. On the contrary, mice accumulated in large lipid droplets, and smooth reticulum fractions in addition to nuclear and plasma membranes. These results show that the squalene cellular localization may change according to experimental setting and be a starting point to characterize the mechanisms involved in the protective action of dietary squalene in several pathologies

Dietary squalene modifies plasma lipoproteins and hepatic cholesterol metabolism in rabbits

To evaluate the effects of squalene, the main unsaponifiable component of virgin olive oil, on lipid metabolism, two groups of male New Zealand rabbits were fed a 1% sunflower oil-enriched regular diet or the same diet containing 0.5% squalene for 4 weeks. Plasma triglycerides, total- and HDL-cholesterol and their lipoproteins were assayed. Analyses of hepatic lipid droplets, triglycerides, total- and non-esterified cholesterol, squalene, protein and gene expression, and cholesterol precursors were carried out. In the jejunum, the squalene content and mRNA and protein APOB expressions were measured. Finally, we studied the effect of cholesterol precursors in AML12 cells. Squalene administration significantly increased plasma total cholesterol, mainly carried as non-esterified cholesterol in IDL and large LDL, and corresponded to an increased number of APOB100-containing particles without accumulation of triglycerides and decreased reactive oxygen species. Despite no significant changes in the APOB content in the jejunum, the latter displayed increased APOB mRNA and squalene levels. Increases in the amounts of non-esterified cholesterol, squalene, lanosterol, dihydrolanosterol, lathosterol, cholestanol, zymostenol, desmosterol and caspase 1 were also observed in the liver. Incubation of AML12 cells in the presence of lanosterol increased caspase 1. In conclusion, squalene administration in rabbits increases the number of modified APOB-containing lipoproteins, and hepatic cholesterol biosynthesis is linked to caspase 1 probably through lanosterol. © The Royal Society of Chemistry

Dietary Squalene Induces Cytochromes Cyp2b10 and Cyp2c55 Independently of Sex, Dose, and Diet in Several Mouse Models

Scope: To investigate the effects of squalene, the main hydrocarbon present in extra virgin olive oil, on liver transcriptome in different animal models and to test the influence of sex on this action and its relationship with hepatic lipids. Methods and Results: To this purpose, male C57BL/6J Apoe-deficient mice are fed a purified Western diet with or without squalene during 11 weeks and hepatic squalene content is assessed, so are hepatic lipids and lipid droplets. Hepatic transcriptomic changes are studied and confirmed by RT-qPCR. Dietary characteristics and influence of squalene doses are tested in Apoe-deficient on purified chow diets with or without squalene. These diets are also given to Apoa1 and wild-type mice on C57BL/6J background and to C57BL/6J xOla129 Apoe-deficient mice. Squalene supplementation increases its hepatic content without differences among sexes and hormonal status. The Cyp2b10 and Cyp2c55 gene expressions are significantly up-regulated by the squalene intake in all models, with independence of sex, sexual hormones, dietary fat content, genetic background and dose, and in Apoe-deficient mice consuming extra-virgin olive oil. Conclusion: Hepatic squalene increases the expression of these cytochromes and their changes in virgin olive oil diets may be due to their squalene content