In vivo bioavailability of polyphenols from grape by-product extracts, and effect on lipemia of normocholesterolemic Wistar rats.

BACKGROUND: The direct use of phenolic extracts from grape by-products can be useful when formulating functional food to improve consumer health. The use of phenolic extracts instead of pure polyphenols as an ingredient is relevant in this context. The present study investigated the bioavailability and absorption of polyphenols from grape by-product extracts and their health effect on cholesterolemia, by adding the extract (GE) to Wistar rats diet (50 g kg-1 ) in vivo. RESULTS: GE caused the appearance of (+)-catechin, myricetin and quercetic acid in plasma and liver. (+)-Catechin was the most abundant compound (6 µg mL-1 in plasma and 0.7 µg mg-1 protein in liver), whereas no phenolic compounds were detected in plasma or liver in the control group. Similarly, 3,4-hydroxyphenylacetic, a major product of polyphenol digestion, was detected in the plasma, liver and urine of the GE-group only. GE-group had significantly lower cholesterol level and lower total cholesterol/high-density lipoprotein ratio in plasma. Total bile acid content significantly increased in fecal matter after 24 h administration of the GE-enriched diet. CONCLUSION: Grape extract polyphenols are partially bioavailable and showed improvement in lipid metabolism. Thus, the results suggest that GE is promising as a functional ingredient in the prevention of hypercholesterolemia. © 2018 Society of Chemical Industry.

Bioaccessibility of hydroxytyrosol and n-3 fatty acids as affected by the delivery system: simple, double and gelled double emulsions.

This study examines the influence of different food-grade n-3 PUFA-enriched simple emulsion (SE), double emulsion (DE) and gelled double emulsion (GDE) delivery systems on the extent of lipolysis, antioxidant capacity and the bioaccessibility of hydroxytyrosol (HTy). GDE emulsion offered better protection for HTy (89%) than the other systems (79% in SE and DE). The reducing capacity of the emulsions containing HTy were not altered during oral digestion. However, "in vitro" gastric and intestinal phases significantly reduced the antioxidant activity of all systems. The structural and physical state of GDE entailed a slowing-down of triacylglyceride hydrolysis (36.4%) in comparison with that of SE and DE (22.7 and 24.8% for SE and DE, respectively).

Glucomannan and glucomannan plusspirulina added to pork significantly block dietary cholesterol effects on lipoproteinemia, arylesterase activity, and CYP7A1 expression in Zucker fa/fa rats

Zucker fa/fa rats easily develop dyslipidemia and obesity. Restructured pork (RP) is a suitable matrix for including functional ingredients. The effects of glucomannan- RP or glucomannan plus spirulina-enriched RP on plasma lipid/lipoprotein levels, cytochrome P450 7A1 (CYP7A1) expression, and arylesterase activity in growing fa/fa rats fed high-energy, high-fat cholesterol-enriched diets were tested. Groups of six rats each received diet containing 15 % control-RP (C), 15 % glucomannan-RP diet (G), 15 % glucomannan + spirulina-RP diet (GS), and same diets enriched with 2.4 % cholesterol and 0.49 % cholic acid (cholesterol-enriched control (HC), cholesterol-enriched glucomannan (HG), and cholesterol-enriched glucomannan + spirulina (HGS) diets) over a 7-week period. C diet induced obesity, severe hyperglycemia, moderate hypercholesterolemia, and hypertriglyceridemia. Those facts were not significantly modified by G or GS diets. G diet increased CYP7A1 expression but decreased the total cholesterol/high density lipoproteins (HDL)-cholesterol ratio (p < 0.05) vs. C diet. GS vs. G diet increased (p < 0.05) CYP7A1 expression. HC vs. C diet reduced food intake, body weight gain, and plasma glucose (p < 0.01) but increased cholesterolemia (p < 0.01), lipidemia (plasma cholesterol plus triglycerides) (p < 0.001), cholesterol/triglyceride ratio in very low density lipoproteins (VLDL), and HDL (p < 0.05), cholesterol transported by VLDL and intermediate density lipoproteins (IDL) + low density lipoproteins (LDL), total cholesterol/HDL-cholesterol ratio and CYP7A1 expression (at least p < 0.05). HG and HGS diets vs. HC noticeably reduced lipidemia (p < 0.001), normalized VLDL and IDL + LDL lipid composition, and increased CYP7A1 expression (p < 0.01) but did not modify the cholesterol/HDL-cholesterol ratio. HGS vs. HG decreased triglyceridemia, the triglyceride-glucose (TyG) index and increased arylesterase/HDL-cholesterol activity (p < 0.05). In conclusion, G- and GS-RP act as functional foods and notably blocked the dietary cholesterol effects. In addition, HGS-RP improved the glucomannan hypolipidemic effects, increased arylesterase/HDL-cholesterol activity, and decreased insulin resistance

Glucomannan and glucomannan plus spirulina added to pork significantly block dietary cholesterol effects on lipoproteinemia, arylesterase activity, and CYP7A1 expression in Zucker fa/fa rats.

Zucker fa/fa rats easily develop dyslipidemia and obesity. Restructured pork (RP) is a suitable matrix for including functional ingredients. The effects of glucomannan- RP or glucomannan plus spirulina-enriched RP on plasma lipid/lipoprotein levels, cytochrome P450 7A1 (CYP7A1) expression, and arylesterase activity in growing fa/fa rats fed high-energy, high-fat cholesterol-enriched diets were tested. Groups of six rats each received diet containing 15% control-RP (C), 15% glucomannan-RP diet (G), 15% glucomannan + spirulina-RP diet (GS), and same diets enriched with 2.4% cholesterol and 0.49% cholic acid (cholesterol-enriched control (HC), cholesterol-enriched glucomannan (HG), and cholesterol-enriched glucomannan + spirulina (HGS) diets) over a 7-week period. C diet induced obesity, severe hyperglycemia, moderate hypercholesterolemia, and hypertriglyceridemia. Those facts were not significantly modified by G or GS diets. G diet increased CYP7A1 expression but decreased the total cholesterol/high density lipoproteins (HDL)-cholesterol ratio (p < 0.05) vs. C diet. GS vs. G diet increased (p < 0.05) CYP7A1 expression. HC vs. C diet reduced food intake, body weight gain, and plasma glucose (p < 0.01) but increased cholesterolemia (p < 0.01), lipidemia (plasma cholesterol plus triglycerides) (p < 0.001), cholesterol/triglyceride ratio in very low density lipoproteins (VLDL), and HDL (p < 0.05), cholesterol transported by VLDL and intermediate density lipoproteins (IDL) + low density lipoproteins (LDL), total cholesterol/HDL-cholesterol ratio and CYP7A1 expression (at least p < 0.05). HG and HGS diets vs. HC noticeably reduced lipidemia (p < 0.001), normalized VLDL and IDL + LDL lipid composition, and increased CYP7A1 expression (p < 0.01) but did not modify the cholesterol/HDL-cholesterol ratio. HGS vs. HG decreased triglyceridemia, the triglyceride-glucose (TyG) index and increased arylesterase/HDL-cholesterol activity (p < 0.05). In conclusion, G- and GS-RP act as functional foods and notably blocked the dietary cholesterol effects. In addition, HGS-RP improved the glucomannan hypolipidemic effects, increased arylesterase/HDL-cholesterol activity, and decreased insulin resistance.

Influence of Picual olive ripening on virgin olive oil alteration and stability during potato frying.

Ripening modifies oil attributes and composition. However, the influence of olive ripening on virgin olive oil (VOO) thermal oxidative stability on food-frying has not been studied yet. Oils from Picual olives of low (VOO1), medium (VOO2), and high (VOO3) ripeness were obtained, and their thermal oxidative stability during 40 potato-fryings was tested. Unused VOO1 showed higher antioxidant content and oxidative stability than VOO2 and VOO3. Polar compounds (PC), oligomers, and altered fatty acid methyl esters (polar-FAME) increased, whereas linoleic acid, polyphenols, and tocopherols decreased in the three VOOs through frying. The alteration was lower in VOO1, followed by VOO2 (0.105, 0.117, and 0.042 g/100 g oil less of PC, oligomers and polar-FAME per frying, respectively, in VOO1 than in VOO3). In conclusion, VOO obtained from low-ripeness Picual olives should be preferred when frying fresh-potatoes due to its higher thermal and oxidative stability, permitting a higher number of potato-frying uses.

Protective effects of sea spaghetti-enriched restructured pork against dietary cholesterol: effects on arylesterase and lipoprotein profile and composition of growing rats.

There is a general assumption that seaweeds are hypocholesterolemics and antioxidants. However, controversial results suggest specific properties for each individual alga. This study aims to assess the effect of including Sea Spaghetti alga (S) in a restructured-pork (RP) diet, both enriched and not enriched with dietary cholesterol, on arylesterase (AE) activity and lipoprotein concentration and composition of Wistar rats. Four groups of 10 growing male Wistar rats were each fed a mix of 85% AIN-93M diet and 15% freeze-dried RP for 5 weeks. The control group (C) consumed control RP-C; the S group consumed RP-S with 5% seaweeds; the Chol-C group consumed the C diet but enriched with cholesterol (2.43%) and cholic acid (0.49%); the Chol-S group consumed the S diet but enriched with cholesterol and cholic acid. AE activity was five times higher (P<.01) in S compared with C rats, but three times lower in Chol-S compared with Chol-C rats (P<.01). The Chol-C diet induced hypercholesterolemia but reduced triglycerides (TG), giving rise to the presence of very low-density lipoprotein (VLDL) that was enriched in cholesterol. The Chol-S diet partially blocked (P<.001) the hypercholesterolemic induction of the Chol-C diet, and reduced TG levels (P<.05) with respect to S rats. The cholesterol supplementation increased total cholesterol, VLDL-cholesterol, and intermediate-density lipoprotein+LDL-cholesterol (IDL+LDL)-cholesterol (P<.001) in Chol-C rats, but the effect was lower in the Chol-S diet. In conclusion, RP-S increases the antioxidant capacity within a noncholesterol enriched diet while improving the lipoprotein profile within a cholesterol-enriched diet.

Effects of Nori- and Wakame-enriched meats with or without supplementary cholesterol on arylesterase activity, lipaemia and lipoproteinaemia in growing Wistar rats.

Some seaweeds exert antioxidant and hypocholesterolaemic properties. The effects of diets including restructured meats (RM) containing Wakame (W) or Nori (N) algae on arylesterase (AE) activity and lipoprotein concentration and composition were tested. In the present study, six groups of ten male growing Wistar rats each were fed a mix of 85 % AIN-93M diet and 15 % freeze-dried RM for 35 d. The control group (C) consumed control RM, the W and N groups consumed RM with 5 % W and 5 % N, respectively. The cholesterol-enriched C (CC), W (CW) and N (CN) groups consumed their corresponding basal diets with supplementary cholesterol (2·43 %) and cholic acid (0·49 %). Cholesterol in the diet induced lower (P < 0·001) growth ratios. Both W and N diets significantly increased AE activity. VLDL-cholesterol values were lower in N rats than in W rats. AE activity increased (P < 0·001) in CC and CW rats but not in CN rats compared with their corresponding counterparts. AE was lower (P < 0·05) in the CN group than in the CC and CW groups. The CN diet partially blocked (P < 0·001) the hypercholesterolaemic induction observed in CC and CW diets and reduced TAG levels (at least P < 0·05) with respect to those of CC rats. Although dietary cholesterol supplementation increased total cholesterol, VLDL-cholesterol and (intermediate-density lipoprotein+LDL)-cholesterol (all P < 0·001) in all rats, the CN diet moderately improved the lipoprotein profile of hypercholesterolaemic rats. Changes in AE activity and plasma cholesterol in CN rats but not in CW rats suggest a possible relationship between the two parameters. It is concluded that inclusion of RM enriched with N may be used in hypercholesterolaemic diets to improve lipoprotein metabolism.

Effect of thermally oxidized oil and fasting status on the short-term digestibility of ketolinoleic acids and total oxidized fatty acids in rats.

Western diets contain substantial amounts of lipid oxidation products. The effects of fasting status and oil oxidation on short-term digestibility of oxidized fatty acids (ox-FA) and ketolinoleic acids (keto-LA) of sunflower oils were evaluated. Twelve rats were fasted overnight for 3 days, whereas another 12 rats had free access to diet. From day 4, and for 4 days, two groups of rats, nonfasted (NFT) and fasted (FT), received 1 g/100 g body weight of sunflower oil reused from 40 deep-frying processes, and two control groups of rats, nonfasted (NFC) and fasted (FC), received the same amount of fresh oil. Ox-FA and keto-LA were determined 5 h after the last administration in the various gastrointestinal compartments together with the intraintestinal MDA. Oil digestibility was highest in NFC and lowest in FT rats. NFT and FT rats had higher (at least P < 0.05) intraintestinal MDA, ox-FA, and keto-LA than NFC and FC; MDA and keto-LA concentrations correlated with each other (P < 0.05). Ox-FA and keto-LA levels found in the gastric lumen suggest that digestion contributes to the formation of these compounds. Total ox-FA and keto-LA were efficiently absorbed during the first 5 h after test oil administration, but poorly absorbed in the case of fresh oils. Oil alteration influenced the digestibility of these compounds more than fasting, although the digestibility of oxidized oil was significantly affected by fasting.

Wakame and Nori in restructured meats included in cholesterol-enriched diets affect the antioxidant enzyme gene expressions and activities in Wistar rats.

The effects of diets including restructured meats (RM) containing Wakame or Nori on total liver glutathione status, and several antioxidant enzyme gene expressions and activities were tested. Six groups of ten male growing Wistar rats each were fed a mix of 85% AIN-93 M diet and 15% freeze-dried RM for 35 days. The control group (C) consumed control RM, the Wakame (W) and the Nori (N) groups, RM with 5% Wakame and 5% Nori, respectively. Animals on added cholesterol diets (CC, CW, and CN) consumed their corresponding basal diets added with cholesterol (2%) and cholic acid (0.4%). Alga and dietary cholesterol significantly interact (P < 0.002) influencing all enzyme expressions but not activities. The cholesterol supplement decreased most enzyme expression and activity. W-RM vs. C-RM increased (P < 0.05) expression of GPx, GR, Mn-SOD, and Cu,Zn-SOD and decreased that of catalase. N-RM vs. C-RM increased (P < 0.05) expression of catalase and Mn-SOD. GR activity increased in W-RM rats while SOD activity increased, but that of Se-GPx decreased in N animals. W-RM increased total and reduced glutathione and decreased the redox index. CN diet induced significantly lower plasma cholesterol levels (P < 0.001) than the CW diet. In conclusion, Nori-RM is a hypocholesterolemic food while Wakame-RM is an antioxidant food. This should be taken into account when including this kind of RM as potential functional foods in human.

Fasting status and thermally oxidized sunflower oil ingestion affect the intestinal antioxidant enzyme activity and gene expression of male Wistar rats.

The effect of thermally oxidized sunflower oil ingestion on antioxidant levels, enzyme activities and expressions in the small intestine of fed and fasted rats was studied. For three consecutive days, 12 male Wistar rats received 0.5 g of unused sunflower oil/100 g of body weight (controls, C) while another 12 were given 0.5 g of thermally oxidized sunflower oil/100 g of body weight (test group, T). On the night of day 3, 6 rats from each group were fasted (FC and FT, respectively) while the other 6 animals from each group were given free access to food (NFC and NFT, respectively). On day 4, FC and NFC rats received 1 g of unused oil/100 g of body weight, while FT and NFT rats were given 1 g of altered oil/100 g of body weight. Small intestines were extracted after 4 h exposure to the oils. Fasting and oil alteration significantly interacted modifying total, Se-GPx (both, P < 0.001) and non-Se-GPx (P < 0.05) activity, and GPx and Cu,Zn-SOD expressions (both P < 0.001). FT rats showed a significant increase in TBARS (P < 0.05) and catalase activity (P < 0.001) and a decrease in SOD, Se- and non-Se-dependent GPx activities (at least, P < 0.05) with respect to FC and NFT animals. SOD and GPx expressions decreased (p<0.001) but that of TNFalpha increased significantly (P < 0.001) in FT rats with respect to FC and NFT animals. Lengthy fasting and consumption of food containing oxidized fat should both be avoided to prevent intestinal oxidative stress.

Gastric emptying and short-term digestibility of thermally oxidized sunflower oil used for frying in fasted and nonfasted rats.

Four-hour in vivo digestibility of sunflower oil used in frying was tested in fasted and nonfasted rats. For three consecutive days, 12 male Wistar rats received 1 g of unused oil (controls, C), while 12 received 1 g of used oil (test group, T). On the night of day 3, 6 rats from each group were fasted (FC, FT) while the other 6 animals from each group had free access to food (NFC, NFT). On day 4, FC and NFC received 2 g of unused oil, while FT and NFT received 2 g of used oil. Luminal gastric and intestinal fats were studied by column and HPSE chromatography after endogenous corrections. Gastric emptying in FT was significantly slower than in NFT and FC. The luminal gastric fat profile differed from that of the oils administered, suggesting that nonoxidized triacylglycerols passed quickly into the intestines. All glyceridic compounds present in the luminal intestinal fat were affected by oil type (at least P < 0.01). Oil digestibility value order was FT < NFT < FC < NFC. FT and NFT presented lower (P < 0.001) triacylglycerol polymer and dimer digestibilities than NFC and FC. In conclusion, oil type determined luminal intestinal fat compounds and their digestibility more than nutritional status.