Diet-induced changes in alginate- and laminaran-fermenting bacterial levels in the caecal contents of rats

Brown algae contain soluble polysaccharides, such as alginic acid, fucoidan and laminaran. To assess the induction of dietary fiber-fermenting bacteria in the intestine, rats were fed diet containing no dietary fiber (control) or 2% w/w of the polysaccharides for 2 weeks. The levels of dietary fiber-fermenting bacteria in caecal contents were determined using decimal dilution culture containing 1% w/v of the fibers. Caecal microbiota in the rats was analyzed using polymerase chain reaction (PCR)-denaturing gradient gel electrophoresis (DGGE). In the culture method, 4–9 log viable cells/g caecal content of alginate-fermenting bacteria was detected in rats fed alginate, while this was not detected in rats fed the control diet. Although laminaran-fermenting bacteria were detected in control rats (4–9 log viable cells/g), the level observed in rats fed laminaran was 8 or 9 log viable cells/g. On the other hand, fucoidan-fermenting bacteria were not detected in rats fed fucoidan. DGGE analysis showed laminaran administration increased the diversity of bacterial bands. Clostridium spp. and Parabacteroides distasonis were detected as typical species in rats fed alginate and laminaran. The results indicate that the intake of soluble fermentable fibers in edible brown algae can alter the intestinal microbiota and its fermentation capacity.     

Effects of a black rice extract (Oryza sativa L. indica) on cholesterol levels and plasma lipid parameters in Wistar Kyoto rats

This study was designed to evaluate the efficacy of an anthocyanin pigmented rice (e.g. black rice) to mitigate the onset of hypercholesterolemia in rats-fed atherogenic diets. Male Wistar (n = 10/group) rats were fed with atherogenic diets containing 0.5% cholesterol in the presence and in the absence of bile salt (e.g. 0.05% cholic acid) along with a standardized black rice extract (BRE) (e.g. 3%, w/w). All animals were individually housed in stainless steel cages and fed with the experimental diets during a 12-h period for 10 weeks. Body weights of rats were measured every week of the experiment. After 10 weeks fed on experimental diets, rats were sacrificed and plasma total cholesterol, HDL and LDL cholesterol and triacylglycerols were measured immediately. The total cholesterol (TC) content in the liver, heart and aorta, and the concentration of triacylglycerol (TAG) were measured after lipid extraction using Folch method. Rats fed with 0.5% cholesterol containing diets which also included bile salt exhibited a considerably more severe hypercholesterolemia than counterparts fed diets containing only 0.5% cholesterol. The inclusion of the BRE in diets significantly (p < 0.05) decreased the level of TC, LDL–TC and TAG in plasma of rats-fed control diets that either contained or were absent in bile salt (p < 0.05). There were no differences in HDL-level. Liver crude lipids and total cholesterol levels were also significantly (p < 0.05) decreased in experimental groups relative to the control group in both experiments. Thus, supplementation of atherogenic experimental diets with BRE effectively decreased lipid levels in hypercholesterolemic rats. In lieu of the mixture of bioactive components present in BRE, it is possible that more than one mechanism underlying this reduction in lipids is involved.     

Effect of tomato by-products in the diet of Comisana sheep on composition and conjugated linoleic acid content of milk fat

To evaluate the effect of supplementing the diet of Comisana sheep with by-products from industrial tomato manufacture on the fat composition and conjugated linoleic acid (CLA) content of milk fat, two groups of 50 ewes each were fed either total mixed ration standard (TMRS) or total mixed ration with added tomato by-products (TMRA). Milk fat composition was determined by high-resolution gas chromatography (HRGC). The milk fat content for the animals fed the TMRA diet increased by 6.41% (P < 0.01) after six weeks, compared with the animals fed the TMRS diet. The CLA content in the milk fat for the group of animals fed the TMRA diet was 19.8% (P < 0.05) higher than for those fed the TMRS diet, and reached 1.33 g 100 g^?1 fat, while the polyunsaturated fatty acid (PUFA) content increased by a 6.43% (P < 0.05) and reached 7.12 g 100 g^?1 fat. The fatty acid composition showed an increase in the amount of polyunsaturated fatty acids. The n ? 3:n ? 6 ratio increased by 13% in the milk from sheep fed with the TMRA diet. These observations were confirmed by triglyceride analysis, which showed a decrease in the amount of short-chain (C₂₈–C₃₂) and medium-chain (C₃₄–C₄₂) triglycerides after six weeks, while the opposite was observed for the long-chain triglycerides (C₄₄–C₅₄).     

Hypocholesterolemic and hypotensive effects of a fruit-based functional beverage in spontaneously hypertensive rats fed with cholesterol-rich diet

This study was designed to evaluate a polyphenols-rich fruit-based functional beverage on blood pressure, serum and liver lipid profiles in vivo. Sixty spontaneously hypertensive rats were divided into five groups and were fed with a AIN-93G-diet as the normal control (NC), high cholesterol diet as atherogenic control (AC), and the AC diet with three different beverage dosages (0.5X, 1X, 2X), where X is the equivalence of two portion sizes for an adult (X = 10 mL/kg BW/day) after dose translation. Blood pressure was measured during weeks 2 and 4 using a tail-cuff method. Systolic blood pressures were lowered by the beverage at the supplementation of 1X/2X after 2 week but not after 4 week. The oral administration of the beverage at 1X/2X significantly lowered liver cholesterol and total and non-HDL-cholesterol levels in the serum. Thus, the newly formulated beverage possessed hypolipidaemic effects while showing inconsistent effect in lowering the blood pressure.     

Suitability of Protein-Rich Extract from Okra Seed for Formulation of Ready to Use Therapeutic Foods (RUTF)

Protein-rich extract (PRE) was made from okra (Abelmuscus esculentus) seeds. Three versions of feed A, B, and C were formulated using: as sources of protein, A – protein-rich extract from okra seed, B – dehulled and de-fatted okra seed flour (34% protein), C – casein. Each of the feeds was fed to a group of six rats (21 days old mice) for 21 days. The weights of the rats and their droppings were taken at 3-day intervals so were the weights of feed consumed. After 21 days, the rats were decapitated and blood samples harvested. The blood was used for the haematological tests. Liver and heart toxicity indicator including aspartate amino transferase (AST) and alanine amino transferase (ALT) were assayed. Ready-to-use therapeutic food (RUTF) prepared with PRE of okra seeds was formulated and organoleptically assessed in comparison to a standard product. The results showed protein efficiency ratio for A, B, C to be 0.33, 0.14 and 0.47 respectively. The mean weights of the droppings are 2.6, 1.9 and 1.5 respectively, showing significant difference (p ≤ 0.01). The serum AST was 56.5, 72 and 24 (IU/L) respectively. For ALT it was 16.5, 3.1 and 11 respectively. There was no significant difference between the RUTF as well as weaning foods formulated and the standards in terms of overall acceptability (p ≤ 0.01).     

Lingonberry juice lowers blood pressure of spontaneously hypertensive rats (SHR)

Lingonberries (Vaccinium vitis-idaea) are rich in polyphenols, such as proanthocyanidins, anthocyanins, flavonols and flavanols. Polyphenol-rich foods affect vascular health. We previously described improved endothelium-dependent vascular function as well as anti-inflammatory and anti-atherothrombotic effects in spontaneously hypertensive rats (SHR) fed with lingonberry juice. In the present study, we investigated the effects of lingonberry juice dose on blood pressure, vascular function and vascular inflammation in SHR in an 8 weeks’ study. Diluted (1:5) cold-compressed lingonberry juice was given as drinking fluid ad libitum to 5 week old SHR for 8 weeks. Control group (SHR) and normotensive reference group (Wistar-Kyoto) received tap water. Systolic blood pressure (SBP) was monitored weekly. Function of mesenteric artery rings was assessed in standard organ-bath chambers after 8 weeks. Biochemical and clinical chemistry variables were measured from plasma and urine. Lingonberry juice lowered SBP of SHR (p = 0.007). Endothelium-dependent vascular relaxation was not improved. Lingonberry treatment slightly affected plasma inflammatory markers (reduction of NOx and sICAM-1) and clinical chemistry variables (decreased alkaline phosphatase and increased chloride and calcium levels). In conclusion, Lingonberry juice at small concentrations lowers blood pressure in a long-term treatment in SHR.     

Evaluation of gastrointestinal transit in rats fed dietary fibres differing in their susceptibility to large intestine fermentation

The rate and extent of in situ digesta transit after ingestion of diets containing dietary fibres differing in their susceptibility to large intestine fermentation were investigated. One hundred and twenty rats were fed diets containing 7.5% cellulose, inulin, potato fibre or maize starch for 3 days, then the same diets with titanium dioxide (TiO₂) for 3 days, followed by diets without TiO₂ for 2 days. In all diets, TiO₂ ratios rapidly increased within 24 h and reached a maximum level in duodenum, caecum and colon within 2–3 days. Inulin, potato fibre and maize starch-fed rats showed higher levels of caecal short-chain fatty acids, lower faecal polysaccharide concentrations, and reduced faecal output than the rats fed cellulose. Inulin was highly susceptible to caecal microbial fermentation compared to the other dietary fibres. Transit of these dietary fibres through the GI tract was rapid, and the rate of digesta transit was not affected by dietary fibre fermentability in the large intestine.     

A high-resistance-starch rice diet reduces glycosylated hemoglobin levels and improves the antioxidant status in diabetic rats

Diabetes mellitus is a common problem in developed countries. An improved postprandial hyperglycemic peak is one of the main therapeutic targets in diabetic patients. The Wistar rats with streptozotocin (STZ)-induced diabetes were divided into cornstarch (control) and Japonica rice groups, which were fed 640 g starch/kg diets for 4 weeks. The area (means ± SD) under the glucose curve of cornstarch was 173.8 ± 6.9 and Japonica rice diet was 154.3 ± 8.7 mmol × min/L, and the area (means ± SD) under the insulin curve of cornstarch was 12.9 ± 0.1 and Japonica rice diet was 12.0 ± 0.6 nmol × min/L. The glycosylated hemoglobin levels, serum fructosamine and cholesterol concentrations in diabetic rats fed the Japonica rice diet were significantly lower than the control group (P < 0.05). The decreased malondialdehyde levels and increased superoxide dismutase activity and total radical-trapping antioxidant parameter in plasma were also found in rat fed the Japonica rice diet compared to the control. These results suggested that the diet containing high-resistance-starch Japonica rice might reduce glycosylated hemoglobin levels, serum cholesterol concentrations and raised the antioxidant status in the blood.     

Effects of early dietary intervention with a fermentable fibre on colonic microbiota activity and mucin gene expression in newly weaned rats

Colonic microbiota composition and metabolic processes were investigated after modifying the diet immediately post-weaning in rats. Three-week old Sprague–Dawley rats were fed cellulose or inulin diet for 0 day (d), 7 d or 14 d. Real-time PCR quantification showed significantly higher colonic Bifidobacterium spp. in rats fed inulin on d7 and d14. Inulin was effective in increasing the total bacteria, Bacteroides-Prevotella-Porphyromonas group and Faecalibacterium prausnitzii, while decreasing Lactobacillus spp. Higher concentrations of short-chain fatty acids (SCFAs: acetic, butyric and propionic acids), lactic acid and succinic acid were observed in inulin-fed rats. Inulin ingestion altered colonic mucin (MUC)-3 gene expression, and increased the colon crypt depth with more goblet cells per crypt. Significant positive correlations between SCFAs concentrations and MUC3 expression were observed. Dietary supplementation with inulin altered microbiota composition, and their fermentation end-products may have aided in modifying mucin gene expression and morphology in the colon of young rats.     

Polyphenol-rich longan (Dimocarpus longan Lour.)-flower-water-extract attenuates nonalcoholic fatty liver via decreasing lipid peroxidation and downregulating matrix metalloproteinases-2 and -9

Longan-flower-water-extract (LFWE) contains large amounts of phytochemicals where gentisic acid and epicatechin are the major compounds in phenolic acid and flavonoid compound, respectively. The objective of this study was to investigate if drinking LFWE could protect the liver from a hypercaloric dietary habit. Only rats fed the hypercaloric diet (HCD) with 25 g/L (w/v) LFWE solution (HCD_2X) group demonstrated lower (p < 0.05) serum triglyceride levels compared to those fed the HCD with normal distilled water (HCD_NDW) and HCD with 12.5 g/L (w/v) LFWE solution (HCD_1X) groups. However, drinking LFWEs decreased (p < 0.05) hepatic lipids in the HCD rats. Lower (p < 0.05) hepatic MDA levels, GOT and GPT values, and higher (p < 0.05) hepatic GSH levels were observed in HCD rats drinking LFWE. Besides, drinking LFWE downregulated (p < 0.05) gene expressions and activities of hepatic matrix metalloproteinases-2 and -9 (MMP-2/9) in HCD rats. In conclusion, polyphenol-rich LFWE displayed hepatoprotective characteristics against an energy-dense dietary habit.     

Consumption of baru seeds [Dipteryx alata Vog.], a Brazilian savanna nut,prevents iron-induced oxidative stress in rats

The protective effect of plant-based foods in human health has been attributed to the presence of bioactive compounds in all parts of the plants. A previous study found a high level of minerals, tannins and phytic acid in the baru nut (Dipteryx alata Vog.), which is a native fruit of the Brazilian savanna. This study investigated the antioxidant activity (AA) of the aqueous and ethyl acetate extracts of the baru nut and the effect of the consumption of this nut on the oxidative status of rats supplemented orally with iron. The AA was evaluated in vitro using the ferric reducing antioxidant power (FRAP), β-carotene/linoleic acid system and free-radical scavenging (DPPH) assays. The total polyphenol concentration was determined spectrophotometrically using the Folin–Ciocalteu reagent. The in vivo study was conducted in male Wistar rats that were fed an AIN-93M diet with or without 10% baru nut or 1% phytic acid and supplemented daily with iron or saline by gavages for 17 days. The liver, heart and spleen were collected for the determination of the malondialdehyde (MDA), carbonyl protein and iron concentrations. The specific activities of catalase, glutathione reductase, glutathione peroxidase and glutathione S-transferase were also determined in these tissues. A T test was used to compare the results among the rats groups and between the different baru nut extracts (p < 0.05). The aqueous extract of the baru nut contained a higher level of phenolic compounds and a higher antioxidant activity, as measured by FRAP and the β-carotene/linoleic system, relative to the EtOAc extract. The iron supplementation reduced the body weight gain, increased the levels of iron and MDA in the liver and the spleen and increased the carbonyl levels in all three tissues. Consumption of the baru nut reduced the carbonyl levels in the liver, heart and spleen of the iron-supplemented rats (p = 0.002, 0.012 and 0.036, respectively) relative to the heart carbonyl level of rats that were fed the control diet (p = 0.000); it also marginally reduced the iron-induced lipid oxidation in the liver (p = 0.117) and the spleen (p = 0.074). Phytic acid reduced the carbonyl level in the spleen (p = 0.020) and marginally reduced the carbonyl level in the liver (p = 0.098) of iron-supplemented rats. These results demonstrated that the consumption of the baru nut protects tissues against iron-induced oxidative stress, and the phytic acid from the baru nut may be partially responsible for this protective effect; however, other compounds such as phenols may also be involved.     

Lipopolysaccharide derived from the digestive tract provokes oxidative stress in the liver of dairy cows fed a high-grain diet

The aims of this study were to measure oxidative stress parameters and to investigate the molecular mechanism triggered by grain-induced subacute ruminal acidosis in mid-lactation cows. Twelve Holstein-Friesian cows with an average weight of 455 ± 28 kg were divided into 2 groups and subjected to 2 diets over 18 wk: either a low-grain (forage-to-concentrate ratio = 6:4) or a high-grain (forage-to-concentrate ratio = 4:6) diet based on dry matter. Being fed a long-term high-grain diet resulted in a significant decrease in rumen pH and a significant increase in ruminal lipopolysaccharide (LPS) at 4 h postfeeding in the morning. The increase was also observed in LPS concentrations in the portal vein, hepatic vein, and jugular vein blood plasma as well as reduced milk yield in a high-grain diet. Cows fed a high-grain diet had lower levels of catalase and glutathione peroxidase (GPx) activity and total antioxidant capacity than cows fed a low-grain diet; however, super oxide dismutase (SOD) activity and malondialdehyde (MDA) levels were higher in both the liver and the plasma of high-grain than in low-grain cows. Positive correlations were observed between plasma LPS versus hepatic MDA, plasma MDA, and hepatic SOD activity, whereas hepatic GPx and plasma GPx were negatively correlated with plasma LPS. The relative mRNA abundances of GPX1 and CAT were significantly lower in the liver of cows fed a high-grain diet than those fed a low-grain diet, whereas SOD1 was significantly higher in cows fed a high-grain diet than cows fed a low-grain diet. The expression levels of Nrf2, NQO1, MT1E, UGT1A1, MGST3, and MT1A were downregulated, whereas NF-kB was upregulated, in cows fed a high-grain diet. Furthermore, nuclear factor E2-related factor 2 (Nrf2) total protein and mRNA levels were significantly lower than in low-grains. Our results demonstrate the relationship between the translocated LPS and the suppression of cellular antioxidant defense capacity, which lead to increased oxidative stress and suggests that the Nrf2-dependent antioxidant response may be affected by higher levels of LPS translocated to the bloodstream.     

Influence of supplementing vitamin C to yearling steers fed a high sulfur diet during the finishing period on meat color,tenderness and protein degradation,and fatty acid profile of the longissimus muscle

The objective was to determine the influence of vitamin C (VC) supplemented for approximately 102 d during the finishing period on color, tenderness, and fatty acid profile of longissimus thoracis (LT; n = 136) from steers fed a 0.55% sulfur diet. Treatments included 4 supplemental VC concentrations: 1) 0 (CON), 2) 5 (5VC), 3) 10 (10VC), or 4) 20 (20VC) g VC·h^− 1∙ d^− 1 in a common diet. Increasing supplemental VC decreased (P < 0.01) L*, but increased (P < 0.01) vitamin E and tended to increase (P ≤ 0.07) calcium and iron content of steaks. No VC (P ≥ 0.25) effect was noted for WBSF, calpain-1 autolysis, troponin T degradation, or most fatty acid profiles. A quadratic effect (P ≤ 0.03) was observed for cholesterol and CLA content of LT. Under the conditions of our study, supplementing VC to steers fed a 0.55% sulfur diet late in the finishing period did not influence color or tenderness, but increased the vitamin E content.     

Rennet-induced coagulation of enzymatically cross-linked casein micelles

The enzymatic cross-linking of casein micelles with transglutaminase had an adverse influence on rennet-induced coagulation. Incubation with transglutaminase at 30 °C progressively reduced the levels of monomeric caseins and increased rennet flocculation time (RFT) in a Berridge test. For incubation up to 3 h at 30 °C, the reciprocal of the RFT was linearly correlated with the level of residual monomeric κ-casein, indicating that at complete cross-linking flocculation is absent. After treatment for 4–24 h at 30 °C, no residual monomeric κ-casein was detected and no rennet-induced flocculation of the casein micelle suspension was observed. Monitoring rennet-induced coagulation by diffusing wave spectroscopy revealed that transglutaminase-induced inhibition of rennet-induced coagulation of casein micelles is primarily due to an inhibition of the secondary phase of rennet coagulation, i.e., the gelation and gel-firming phase of the casein micelle coagulation. The gelation and fusion of κ-casein-depleted para-casein micelles as in normal milk appears to be absent if the casein macropeptide remains attached to the casein micelle.     

The effects of strawberry,black currant,and chokeberry extracts in a grain dietary fiber matrix on intestinal fermentation in rats

The objective of this work was to study the composition, hydration properties and oil holding capacity, antioxidant properties and the physiological effects on the digestive system of dietary preparations containing wheat or oat fiber enriched with polyphenol extracts from strawberry, chokeberry, and black currant pomace. By the addition of black currant, strawberry and chokeberry polyphenol extracts to grain fibers preparations with corresponding polyphenol content of 0.7%–0.8%, 1.1%–1.2%, and 2.5%–2.9% were obtained. The preparations were used as part (8%) of a modified AIN-93 diet given to growing Wistar rats (8 animals per group) over a period of 4 weeks. The highest antioxidant potential had grain–chokeberry preparations with the greatest polyphenol content, while grain–black currant preparations exhibited the lowest antioxidant potential with the smallest polyphenol content. The addition of strawberry and chokeberry extracts caused a decrease in the activity of bacterial β-glucosidase and α-galactosidase, while black currant extract led to increased activity of β-galactosidase and β-glucuronidase. The production of short chain fatty acids (SCFAs) in the caecum of rats fed the grain–strawberry preparation, rich in ellagitannins, was considerably higher than the grain–black currant preparation, rich in proanthocyanidins and anthocyans, or the grain–chokeberry preparation with the highest polyphenol content (78.3 vs. 64.7 vs. 56.3 μmol/100 g body weight, p = 0.012). In comparison to preparations without polyphenols only chokeberry extract significantly decreased SCFA concentration. The grain–strawberry preparations were characterized by a higher antioxidant potential per unit of polyphenol content and exhibited a more beneficial influence on the fermentation processes in the caecum of rats than the grain–black currant and grain–chokeberry preparations.     

Effects of chestnut tannins on carcass characteristics,meat quality,lipid oxidation and fatty acid composition of rabbits

Seventy two male Bianca Italiana rabbits were used to study the effects of the inclusion (0%, 0.5%, and 1.0%) of a natural extract of chestnut wood (Silvafeed ENC) in the diet on productive traits, carcass characteristics, meat quality, lipid oxidation and fatty acid composition of rabbit meat. Results showed ENC had no significant effect on live weight, productive traits, hot carcass weight, dressing percentage, skin weight, pH, cooking losses, shear force and colour. The iron content was higher in Longissimus thoracis et lumborum (LTL) muscle of rabbit fed the ENC 1.0% diet than the control group. TBARS average values in the group ENC 0.5% were significantly lower (P < 0.05) than in the control and ENC 1.0% groups. Myristic acid (C14:0; P < 0.01), palmitoleic acid (C16:1 cis-9; P < 0.05) and pentadecanoic acid (C15:0; P < 0.01) contents were lower in LTL muscle of rabbits fed the ENC 1.0% diet, whereas the palmitic acid (C16:0) content was higher (P < 0.05) in the rabbits of this group. Moreover, the rabbits fed with the ENC 0.5% diet had lower (P < 0.01) levels of trans-vaccenic acid (C18:1 trans-11) compared to rabbits fed with the control diet. No significant differences were observed in saturated (SFA), monounsaturated (MUFA), polyunsaturated (PUFA) fatty acids, as well as in PUFA/SFA and n − 6/n − 3 ratios among the groups.     

Persistence of chlorpyrifos-methyl in corn silage and effects of feeding dairy cows the treated silage

Corn was sprayed in the field at dent stage of maturity with chlorpyrifos-methyl [O, O,-dimethyl O-(3, 5, 6-trichloro-2-pyridyl) phosphorothioate] at .56, 1.12, and 2.24 kg per hectare, ensiled 1 day later, and methodology for detection of residues was developed. Losses of total residues (chlorpyrifos-methyl and its pyridinol hydrolysis product) through 83 days of ensiling were equivalent to 55, 71, and 76% of that applied. Beginning 83 days post ensiling, control and treated silages were fed to 16 cows, 4 per treatment, for 42 days during which chlorpyrifos-methyl averaged .35, .87, and 1.85 ppm, and was stable. The pyridinol averaged .44, .79, and 1.75 ppm but continued to decline and during the last week of feeding averaged only 32% of that in silage fed the 1st wk. Residue intakes amounted to .009, .022, and .054 mg chlorpyrifos-methyl and .012, .020, and .051 mg of pyridinolk/g body weight and failed to affect silage intake, milk production, blood cholinesterase activity, or body weight gains. Traces of chlorpyrifos-methyl (.003 ppm or less) were only in milk from cows on the 2.24 kg treatment. Milk from all cows fed treated silage contained traces of the pyridinol (.011 ppm or less). No trace of the O-analog of chlorpyrifos-methyl was in any sample, and all milk, urine, and feces were free of residues within 1 wk after the cows were withdrawn from treated silage.     

β-Conglycinin (7S) and glycinin (11S) exert a hypocholesterolemic effect comparable to that of fenofibrate in rats fed a high-cholesterol diet

The hypocholesterolemic effect of isolated soybean proteins and fenofibrate in rats was compared. Forty-five rats were divided into five groups: standard (STD; casein), high cholesterol (HC; STD plus 1% cholesterol/0.5% cholic acid), HC + β-conglycinin, HC + glycinin and HC + fenofibrate. The proteins and the drug were administered by gavage for 28 days. The proteins decreased total cholesterol (TC) and triacylglycerol (TG) in the plasma of the rats fed HC diet, to values very close to those fed on fenofibrate. High density lipoprotein cholesterol (HDL-C) levels in the plasma were increased by the β-conglycinin, glycinin and fenofibrate groups. The largest TC reduction in the liver was observed in the fenofibrate group; in contrast, the β-conglycinin and glycinin groups exhibited reduced the levels of hepatic TG and TC. Based on these data, it could be suggested that the oral daily administration of isolated soybean proteins, in the range of 2.75% of the protein ingested daily, can promote a reduction in TC and TG in the plasma of rats fed hypercholesterolemic diets.     

Porcine artery elastin preparation reduces serum cholesterol level in rats

The effect of porcine artery elastin on serum cholesterol level was investigated in rats fed a cholesterol-free diet. Rats were fed for 4 weeks, with a diet (ED) containing 15% casein and 5% of porcine artery elastin in comparison with a diet (CD) containing 20% casein. The total serum and non-HDL-cholesterol concentrations were lower (P < 0.001) in ED-fed group than the CD-fed group at the end of the experiment. Caecal propionate concentration and Bifidobacterium and Lactobacillus population were higher (P < 0.05) in ED-fed group than the CD-fed group. The results of this study suggest that porcine artery elastin could be considered as a functional dietary protein with hypocholesterolaemic ability. Favourable amino acid composition and lysine derived cross links may at least be partially responsible for the hypocholesterolaemic ability of ED. Moreover, the higher caecal propionic acid concentration in the ED-fed group may have suppressed the cholesterol synthesis in the liver, and reduced the serum cholesterol level.     

Blood pressure-lowering properties of chokeberry (Aronia mitchurinii,var. Viking)

The blood pressure-lowering properties of lyophilized chokeberry juice and polyphenols were monitored using in vitro angiotensin-converting enzyme (ACE) inhibition measurement and a 10 day in vivo study with spontaneously hypertensive rats (SHR). Juice and polyphenols indicated weak ACE-inhibitory activity. The IC₅₀ values for polyphenols and juice were 1.5–2.5 and 4.5 mg dry matter/ml, respectively. In the SHR study the blood pressure-lowering effects of juice and polyphenol extract seemed to be short-term and were generally highest after 3 h from administration (50 mg/kg/day) when mean reductions in systolic blood pressure were 20 ± 8 and 15 ± 7 mm Hg, respectively. Corresponding mean decreases in diastolic blood pressure were 23 ± 6 and 13 ± 2 mm Hg in juice and polyphenol groups, respectively. It was concluded that both chokeberry juice and polyphenols had blood pressure-lowering effects. We hypothesize that chokeberry polyphenols enhance endothelial nitric oxide production with an ACE-independent mechanism, e.g. by activation of endothelial nitric oxidase enzyme; this is yet to be verified.