Polyphenol-rich phloem enhances the resistance of total serum lipids to oxidation in men

The impact of consuming technologically processed functional foods enriched/fortified with (poly)phenols on cardiometabolic risk factors: a systematic review of randomized controlled trials

Cardiovascular diseases are a major global cause of death and healthcare costs, emphasizing the need for effective prevention and management of cardiometabolic risk factors. One promising approach is the consumption of technologically processed functional foods enriched/fortified with (poly)phenols. The current systematic review aimed to evaluate the human clinical trials evidence on the effect of intake of these foods on reducing the most common cardiometabolic risk factors. 12 randomized controlled studies were included in the systematic review, with varying food intake amounts (27-360 g/day) and (poly)phenol doses (32.5-850 mg/day). These interventions included consumption of functional bakery goods, cereal bars, pasta, chocolate, and yogurt, with supplementation periods spanning from 2 to 52 wk. Several foods, such as green tea extract-fortified rye bread and olive fruit (poly)phenol-fortified yogurt, significantly lowered blood pressure. Flavonoid-enriched chocolate, hydroxytyrosol-fortified bread, and other products influenced glucose metabolism. Additionally, various functional foods were associated with improved blood lipid levels. While these results indicate the health advantages of consuming technologically processed functional foods enriched/fortified with (poly)phenols, caution is warranted due to the scarcity and limitations of existing studies. Further research is needed to confirm and expand upon these results in the prevention and management of cardiometabolic risk factors.

Tannins of Conifer Bark as Nordic Piquancy-Sustainable Preservative and Aroma?

Bark of Norway spruce and Scots pine trees contain large amounts of condensed tannins. Tannins extracted with hot water could be used in different applications as they possess antioxidative and antimicrobial activities. The use of bark tannins as e.g., food preservatives calls for increases in our knowledge of their antioxidative activities when applied in foodstuffs. To assess the ability of bark tannins to prevent lipid oxidation, hot water extracts were evaluated in a liposome model. Isolated tannins were also applied in dry-cured, salty meat snacks either as liquid extracts or in dry-powder form. Consumer acceptance of the snacks was tested by a sensory evaluation panel where outlook, odor, taste, and structure of the snacks were evaluated and compared to a commercial product without tannin ingredients. Our results show that conifer bark tannin-rich extracts have high capacity to prevent lipid oxidation in the liposome model. The efficacies of pine and spruce bark extracts were ten to hundred folds higher, respectively, than those of phenolic berry extracts. The bark extracts did not significantly influence the odor or taste of the meat snacks. The findings indicate that bark extracts may be used as sustainable food ingredients. However, more research is needed to verify their safety.

The Bioprotective Effects of Polyphenols on Metabolic Syndrome against Oxidative Stress: Evidences and Perspectives

Polyphenols are the general designation of various kinds of phytochemicals, mainly classified as flavonoids and nonflavonoids. Polyphenolic compounds have been confirmed to exhibit numerous bioactivities and potential health benefits both in vivo and in vitro. Dietary polyphenols have been shown to significantly alleviate several manifestations of metabolic syndrome, namely, central obesity, hypertension, dyslipidemia, and high blood sugar. This review is aimed at discussing the bioprotective effects and related molecular mechanisms of polyphenols, mainly by increasing antioxidant capacity or oxygen scavenging capacity. Polyphenols can exert their antioxidative activity by balancing the organic oxidoreductase enzyme system, regulating antioxidant responsive signaling pathways, and restoring mitochondrial function. These data are helpful for providing new insights into the potential biological effects of polyphenolic compounds and the development of future antioxidant therapeutics.

Malaysian brown seaweeds Sargassum siliquosum and Sargassum polycystum: Low density lipoprotein (LDL) oxidation, angiotensin converting enzyme (ACE), α-amylase, and α-glucosidase inhibition activities

Two Malaysian brown seaweeds, Sargassum siliquosum and Sargassum polycystum were first extracted using methanol to get the crude extract (CE) and further fractionated to obtain fucoxanthin-rich fraction (FRF). Samples were evaluated for their phenolic, flavonoid, and fucoxanthin contents, as well as their inhibitory activities towards low density lipoprotein (LDL) oxidation, angiotensin converting enzyme (ACE), α-amylase, and α-glucosidase. In LDL oxidation assay, an increasing trend in antioxidant activity was observed as the concentration of FRF (0.04-0.2mg/mL) and CE (0.2-1.0mg/mL) increased, though not statistically significant. As for serum oxidation assay, significant decrease in antioxidant activity was observed as concentration of FRF increased, while CE showed no significant difference in inhibitory activity across the concentrations used. The IC50 values for ACE inhibitory activity of CE (0.03-0.42mg/mL) were lower than that of FRF (0.94-1.53mg/mL). When compared to reference drug Voglibose (IC50 value of 0.61mg/mL) in the effectiveness in inhibiting α-amylase, CE (0.58mg/mL) gave significantly lower IC50 values while FRF (0.68-0.71mg/mL) had significantly higher IC50 values. The α-glucosidase inhibitory activity of CE (IC50 value of 0.57-0.69mg/mL) and FRF (IC50 value of 0.50-0.53mg/mL) were comparable to that of reference drug (IC50 value of 0.54mg/mL). Results had shown the potential of S. siliquosum and S. polycystum in reducing cardiovascular diseases related risk factors following their inhibitory activities on ACE, α-amylase and α-glucosidase. In addition, it is likelihood that FRF possessed antioxidant activity at low concentration level.

Effect of Chocolate and Yerba Mate Phenolic Compounds on Inflammatory and Oxidative Biomarkers in HIV/AIDS Individuals

Flavonoids in cocoa and yerba mate have a beneficial role on inflammation and oxidative disorders. Their effect on HIV individuals has not been studied yet, despite the high cardiovascular risk of this population. This study investigated the role of cocoa and yerba mate consumption on oxidative and inflammatory biomarkers in HIV+ individuals. A cross-over, placebo-controlled, double-blind, randomized clinical trial was conducted in 92 individuals on antiretroviral therapy for at least six months and at viral suppression. Participants were randomized to receive either 65 g of chocolate or chocolate-placebo or 3 g of yerba mate or mate-placebo for 15 days each, alternating by a washout period of 15 days. At baseline, and at the end of each intervention regimen, data regarding anthropometry, inflammatory, oxidative and immunological parameters were collected. High-sensitivity C-reactive protein, fibrinogen, lipid profile, white blood cell profile and thiobarbituric acid reactive substances were assessed. There was a difference between mean concentrations of HDL-c (ANOVA; p ≤ 0.05) among the different regimens: dark chocolate, chocolate-placebo, yerba mate and mate-placebo. When a paired Student t-test was used for comparisons between mean HDL-c at baseline and after each regimen, the mean concentration of HDL-c was higher after supplementation with dark chocolate (p = 0.008).

Lodgepole Pine Cambium (Pinus contorta Dougl. ex Loud. var. latifolia Engelm. ex S. Wats.): a springtime first peoples' food in British Columbia

Lodgepole pine (Pinus contorta var. latifolia) is a tree species utilized for succulent edible cambium and secondary phloem in the spring by Interior First Peoples of the Pacific Northwest. In this article we present a nutritional analysis of this food based on a pooled sample of 17 trees harvested in the Chilcotin region of British Columbia. We also present enzymatic sugar analysis of raw, dried, and cooked lodgepole pine cambium harvested from the Chilcotin and Okanagan regions in British Columbia. In the discussion we interpret the nutrient values of raw lodgepole pine cambium in comparison to dried and cooked cambium, results from other nutritional studies of pine cambium, and nutrients in some other traditional and nontraditional foods.

The inhibitory effect of phenylpropanoid glycosides and iridoid glucosides on free radical production and β2 integrin expression in human leucocytes

Rapid production of reactive oxygen species (ROS) and upregulation of β2 integrin by leucocytes are two important inflammatory responses in human leucocytes. To evaluate whether three phenylpropanoid glycosides (acteoside, crenatoside, and rossicaside B) and two iridoid glucosides (boschnaloside and 8-epideoxyloganic acid) identified from two medicinal plants with similar indications (Orobanche caerulescens and Boschniakia rossica) exhibited anti-inflammatory activity, their effects on N-formyl-methionyl-leucyl-phenylalanine (fMLP) and phorbol-12-myristate-13-acetate (PMA)-activated peripheral human neutrophils (PMNs) and mononuclear cells were examined. Pretreatment with 1–50 μm phenylpropanoid glycoside concentration-dependently diminished PMA- and fMLP-induced ROS production with IC50 values of approximately 6.8–23.9 and 3.0–8.8 μm, respectively. Iridoid glucoside was less effective than phenylpropanoid glycoside with an IC50 value of approximately 8.9–28.4 μm in PMA-activated PMNs and 19.1–21.1 μm in fMLP-activated mononuclear cells. Phenylpropanoid glycosides also effectively inhibited NADPH oxidase (NOX) and displayed potent free radical-scavenging activity, but did not interfere with pan-protein kinase C (PKC) activity. Furthermore, all compounds, except rossicaside B, significantly inhibited PMA- and fMLP-induced Mac-1 (a β2 integrin) upregulation at 50 μm but not that of fMLP-induced intracellular calcium mobilization. These drugs had no significant cytotoxicity as compared with the vehicle control. Our data suggested that inhibition of ROS production, possibly through modulation of NOX activity and/or the radical scavenging effect, and β2 integrin expression in leucocytes indicated that these compounds had the potential to serve as anti-inflammatory agents during oxidative stress.

Ex vivo inhibitory effect on tilapia LDL oxidation and hypolipidemia properties of Glycine tomentella root extract

The ethanolic extract of I-Tiao Gung (GT-E) (Glycine tomentella root extract) was found to reduce the oxidative rate and prolonged lag phase of LDL in human (Homo sapiens) and tilapia (Oreochromis mossambicus). The in vivo effect of GT-E was determined using tilapia as a model. Hyperlipidemia and hypercholesterolemia were induced in fish by feeding commercial feed daily at 2% body mass for 8 weeks, or at 1% body mass for 12 weeks. Thirty two adult male tilapia were randomly divided into two groups and fed with feed containing 1% (w/w) GT-E or control diet for 12 weeks. Specific growth rate was similar between the GT-E group and the control group. Total triacylglycerol, total cholesterol and low-density lipoprotein cholesterol (LDL-C) in plasma of the GT-E group were significantly lower, while plasma total antioxidant status was significantly higher than those of the control group. GT-E fed fish had longer lag phase of Cu2+-induced LDL oxidation and retained more alpha-tocopherol in LDL particles than the control fish. LDL from the GT-E group had more monounsaturated fatty acids and less polyunsaturated fatty acids than the control group indicative of its effect on fatty acids metabolism. GT-E demonstrated hypolipidemic and hypocholesterolemic effects and inhibiting LDL oxidation in tilapia similar to the effects in mammals, thus tilapia can serve as a surrogate animal model for prescreening anti-atherosclerosis effect of natural products.

Consumption of juice fortified with oregano extract markedly increases excretion of phenolic acids but lacks short- and long-term effects on lipid peroxidation in healthy nonsmoking men

Oregano has been shown to possess antioxidant capacity in various in vitro models and has thus been suggested to be potentially beneficial to human health, but studies in humans are lacking. The aim of this study was to investigate the bioavailability and the effects of Origanum vulgare extract supplementation on serum lipids and lipid peroxidation in healthy nonsmoking men. A four-week double-blinded supplementation trial was concluded in which volunteers (n = 45) were randomized to consume daily mango-orange juice (placebo), mango-orange juice enriched with 300 mg/d total phenolic compounds from oregano extract, or mango-orange juice enriched with 600 mg/d total phenolic compounds from oregano extract. The excretion of phenolic compounds was markedly increased in the higher phenolic group as compared to the placebo group, but no significant changes were observed in the safety parameters, serum lipids, or biomarkers of lipid peroxidation.

In vitro antioxidant activities of barley, husked oat, naked oat, triticale, and buckwheat wastes and their influence on the growth and biomarkers of antioxidant status in rats

The study was aimed at verification of the following hypothesis: differences in antioxidant capacity of diets consisting of different cereals and byproducts affect the antioxidant status of the consumers of these diets. To validate that hypothesis this study investigated the contents of polyphenols and alpha-tocopherol as well as the total antioxidant capacity (TAC) in vitro of cereals and their fractions (barley, husked and naked oat, oat bran, and triticale); the nutritional and antioxidant properties of diets containing these cereals, applied in a 4-week feeding experiment on rats, were also assessed. Among the cereals examined, the highest TAC was reported for barley (13.16 micromol of Trolox/g) and the lowest for naked oat (3.84 micromol of Trolox/g). Compared with cereals, the TAC of buckwheat waste was 2-3 times higher (25.2 micromol of Trolox/g). The antioxidant capacity of diets, calculated in vitro, ranged from 6.35 micromol of Trolox/g for naked oat type diet to 10.51 micromol of Trolox/g for barley type diet. Results of an in vitro study were confirmed in changes of glutathione peroxidase (GPx) activities and the level of thiobarbituric acid-reactive substances (TBARS) in the serum of rats fed diets with the highest and lowest antioxidant capacities in vitro; the barley diet increased the activity of GPx (37.63 units/mL) and decreased the level of TBARS (4.82 microg/g), whereas the naked oat diet had an opposite effect (31.16 units/mL and 5.91 microg/g, respectively).