Does dietary inulin affect biological activity of a grapefruit flavonoid-rich extract?

<p>Abstract</p> <p>Background</p> <p>The aim of the study was to verify that the concomitant presence of grapefruit flavonoid extract with inulin in a Western-type diet may provide synergistic effects to the hindgut metabolism, as well as blood lipid and mineral profiles.</p> <p>Methods</p> <p>Forty male Wistar rats were distributed into 4 groups and fed for 28 days with diets rich in fat, cholesterol and protein. A two-way repeated measures ANOVA was applied to assess the effects of inulin (v. sucrose, 5% of the diet), the addition of dietary grapefruit flavonoid extract (diets without or with 0.3% of an extract from hard parts of grapefruit) and the interaction between these two dietary factors.</p> <p>Results</p> <p>When compared to the control sucrose-containing diet, the diet enriched with inulin led to typical changes within the caecum, the main part of hindgut fermentation in rats, such as acidification of the digesta, support of bifidobacteria growth and increase of propionate and butyrate production. The dietary grapefruit flavonoid extract without inulin increased the bulk and pH value of caecal digesta, whereas short-chain fatty acid concentration and the bifidobacteria population were lowered compared to the extract-free diets. Simultaneous dietary addition of both tested components decreased slightly the pH value and increased somewhat the bifidobacteria number and the propionate concentration, however to the level observed with the control sucrose-containing diet. With regard to blood lipids, dietary grapefruit flavonoid extract decreased the triglyceride concentration regardless of the dietary carbohydrate type.</p> <p>Conclusion</p> <p>Inulin does not provide any additional benefit to the blood lipid profile caused by the dietary application of grapefruit flavonoid extract and it does not counteract clearly detrimental effects of the extract in the hindgut. Adding grapefruit extract to the diet must be performed with caution due to possible adverse hindgut responses with overdoses.</p

Effects of Dietary Addition of a Low-Pectin Apple Fibre Preparation on Rats

The aim of this study was to scrutinise if the dietary addition of a low-pectin fibre preparation obtained from apple pomace, the by-product of apple concentrate processing, is able to favourably affect the gut metabolism, antioxidant status and blood bio-markers of the organism, as it takes place when apple fibre is present in the diet as an unprocessed ingredient. The nutritional experiment was performed on rats allocated to 2 groups of 10 animals each and fed for 2 weeks with either a control cellulose-containing diet or an experimental low-pectin apple fibre-containing diet. To induce metabolic disorders a diet rich in saturated fat and fructose was used in both diet-specific groups. The dietary apple fibre preparation (AFP) significantly reduced the activity of sucrase and maltase in the mucosa of the small intestine. In the caecal digesta, the dietary AFP significantly increased bacterial α-glucosidase and α-galactosidase activity, whereas bacterial β-glucuronidase activity was significantly reduced. Also, the content of short chain fatty acids in the caecal digesta was significantly increased after the AFP supplementation. In the blood serum, the dietary AFP significantly reduced the glucose concentration, and decreased the ratio of total cholesterol to HDL cholesterol. In conclusion, the tested dietary AFP is still able to favourably affect the gut metabolism and can also ameliorate blood glucose concentration, which seems to be related to the inhibition of mucosal disaccharidase activities. However, the analysed preparation has no influence on the antioxidant status of the organism and may trigger adverse effects on cholesterol metabolism

The importance of serotonin in the gastrointestinal tract

Introduction. Serotonin also called as 5-hydroxytryptamine (5-HT) is a very important neurotransmitter in the central nervous system, also plays an important role in the gastrointestinal tract. It is known that the basis of the peristaltic reflex in the gut is the result of serotonin release from enterochromaffin cells. The vast majority of serotonin in the human body is associated with the gastrointestinal tract. It is produced by enterochromaffin cells, the activation of which causes the serotonin secretion into the intercellular space and its active action through the receptors. There are seven main types of serotonin receptors and some of them have also subtypes.Description of the current knowledge and conclusions. Serotonin is responsible for some symptoms of carcinoid syndrome. It is the result of higher 5-hydroxytryptamine content in the body. Moreover disrupted serotonin system is found in different gastrointestinal disorders e.g. in gastroesophageal reflux disease, functional heartburn, hypersensitive esophagus, functional dyspepsia, irritable bowel syndrome (both diarrhoea predominant and constipation predominant) as well as in inflammatory bowel diseases. Knowledge of changed mechanisms in particular diseases facilitates the optimal choice of treatment. Drugs affecting the serotonin system in gastroenterological clinical practice are useful especially in the case of abnormalities in the brain - gut axis

Sastav i biološka svojstva etanolnih ekstrakata korijena, kore, sjemenja i listova cikorije

The chemical composition of the ethanol extracts of chicory root, peel, seed and leaf has been determined, in particular their inulin and phenolic fractions. The root and peel extracts were characterized by large mass fractions of inulin (60.1 and 46.8 g per 100 g of fresh mass, respectively), predominantly with degree of polymerization in the range from 3 to 10, while phenolics, determined as caffeoylquinic acids, made up 0.5 and 1.7 g per 100 g of fresh mass, respectively. The leaf and seed extracts had decidedly lower mass fractions of inulin (1.7 and 3.2 g per 100 g of fresh mass, respectively) and higher mass fractions of phenolics (9.6 and 4.22 g per 100 g of fresh mass, respectively) recognized as caffeoylquinic acids, chicoric acid and quercetin glucuronide. The biological properties of a non-inulin fraction from each extract were determined on Wistar rats fed with diets rich in fructose and saturated fat, as a model of metabolic changes related to westernization of human eating habits. The diets contained the same amount of inulin (6 %) with various phenolic fractions. Some changes were noted in the microbial enzymatic activity of the caecum after feeding for 4 weeks with the diet containing the highest mass fraction of phenolics (0.208 %), derived from the mixture of peel and seed extracts (decreased activity of β-galactosidase and β-glucuronidase), as well as with the diet containing leaf extract (decreased β-glucuronidase activity). All the diets showed no essential influence on the caecal concentration and profile of short-chain fatty acids, except acetate, whose concentration decreased significantly in rats fed with the diet enriched with root extract. The addition of peel and leaf extracts to the fructose diets significantly increased the serum antioxidant capacity of lipophilic substances. The study indicates that parts of chicory and its byproducts might be a source of valuable compounds to improve the physiological activity of inulin.Određen je kemijski sastav etanolnih ekstrakata (tj. udjeli inulina i fenola) korijena, kore, sjemenja i listova cikorije. Ekstrakti korijena i kore sadržavali su velike masene udjele inulina, i to u 100 g svježe tvari: korijen 60,1 g i kora 46,8 g, pri čemu je stupanj polimerizacije bio od 3 do 10. Maseni udjel fenola (derivata kofeinske kiseline) u 100 g svježe tvari bio je u ekstraktu korijena 0,5 g, a u ekstraktu kore 1,7 g. Ekstrakti lišća i sjemenja imali su kudikamo manji udjel inulina u 100 g svježe tvari (ekstrakt lišća 1,7 g i ekstrakt sjemenja 3,2 g) i veći maseni udjel fenola u 100 g svježe tvari (ekstrakt lišća 9,6 g i ekstrakt sjemenja 4,22 g). Biološka svojstva fenola, tj. njihov utjecaj na metaboličke promjene prouzročene zapadnjačkim načinom prehrane, ispitana su na štakorima Wistar kojima je davana hrana bogata fruktozom i zasićenim masnim kiselinama. Hrana je sadržavala isti udjel inulina, a različite masene udjele fenola, ovisno o dodanom ekstraktu. Nakon 4 tjedna prehrane hranom s najvećim udjelom fenola od 0,208 % uočene su promjene u aktivnosti enzima mikrobnog podrijetla, izoliranih iz slijepoga crijeva štakora. Utvrđeno je da hrana koja sadržava mješavinu ekstrakata kore i sjemenja smanjuje aktivnost β-galaktozidaze i β-glukuronidaze, dok hrana koja sadržava ekstrakt lišća smanjuje aktivnost samo β-glukuronidaze. Prehrana nije utjecala na koncentraciju i sastav masnih kiselina, osim što je hrana s dodatkom ekstrakta korijena bitno smanjila koncentraciju acetata u slijepom crijevu. Dodatkom ekstrakata kore i lišća hrani bogatoj fruktozom znatno se povećala antioksidativna aktivnost seruma. Studija je pokazala da dijelovi cikorije i njezine prerađevine mogu poslužiti kao izvor vrijednih sastojaka koji poboljšavaju fiziološku aktivnost inulina

<i>Asteraceae</i> Seeds as Alternative Ingredients in a Fibre-Rich Diet: Protein Quality and Metabolic Effects in Rats

We verified whether milk thistle seeds and pot marigold seeds provided valuable components for a fibre-rich diet and how their addition affected body composition, nitrogen balance and lipid metabolism in rats. Growing rats were fed a control diet (5% fibre) or three fibre-rich diets (24% fibre), which contained cellulose as the sole source of fibre (24%; positive control), milk thistle seeds (32%) or pot marigold seeds (39%). All diets were balanced in macronutrients, including total protein content (9%), which was half of the amount recommended for rats to maximise protein absorption and utilisation, and the ratio of plant protein to animal protein (approx. 1:1). After 4 weeks, dietary pot marigold seeds reduced body weight gain, which translated into lower gains of body fat and lean mass in rats (all at p ≤ 0.05). Protein digestibility differed among individual fibre-rich diets (p ≤ 0.05), with the lowest result having been recorded for dietary pot marigold seeds (73%), followed by dietary milk thistle seeds (78%), and the highest result having been recorded for dietary soybean protein isolate (control protein source, 89%). Nitrogen retention was higher with dietary soybean protein isolate (53%) and dietary milk thistle seeds (47%) than with dietary pot marigold seeds (38%) (p ≤ 0.05). In the caecal digesta, the concentrations of the major short-chain fatty acids were almost or >2-fold higher after dietary milk thistle seeds and pot marigold seeds than after the positive control diet (all at p ≤ 0.05). Dietary pot marigold seeds enlarged the liver and increased the plasma activities of liver enzymes but reduced hepatic lipid contents (all at p ≤ 0.05). Certain Asteraceae seeds provide components of varied nutritional quality, with milk thistle seeds being a relatively good source of protein and both types of seeds being a source of fermentable fibre. Pot marigold seeds have potential anti-obesogenic effects, but with the risk of damaging internal organs

Partially defatted rather than native poppy seeds beneficially alter lipid metabolism in rats fed a high-fat diet

Abstract Partially defatted poppy seeds, a by-product of poppy oil cold pressing, could be an interesting dietary supplement for obesity management. The aim of this study was to compare the effects of dietary supplementation with a small amount of native or partially defatted poppy seeds on gastrointestinal function and lipid metabolism in rats fed a high-fat diet. The defatted poppy seeds had, among others, lower fat content and higher fibre and protein content than native poppy seeds. The rats fed with a high-fat diet were characterised by severe metabolic disorders, especially in the liver, and poppy seeds were unable to prevent them. However, depending on the seed form, dietary supplementation with poppy seeds differentially affected the microbial and endogenous lipid metabolism in rats. In the distal intestine, both dietary seed forms stimulated microbial acetate production, and the supplementation with partially defatted poppy seeds additionally inhibited isobutyrate and isovalerate formation, which indicates a reduction in putrefaction. Both dietary seed forms increased cholesterol accumulation in the liver. Only dietary supplementation with partially defatted poppy seeds attenuated visceral fat and hepatic triglyceride accumulations and lowered blood triglyceride concentrations, and at the transcriptional level, the inhibition of SREBP-1c, which upregulates genes responsible for de novo lipogenesis, was additionally observed in this organ. In conclusion, a low and regular consumption of partially defatted poppy seeds may be beneficial in managing obesity-related disorders

The Effect of Hemp (Cannabis sativa L.) Seeds and Hemp Seed Oil on Vascular Dysfunction in Obese Male Zucker Rats

Seeds of industrial hemp (Cannabis sativa L.) contain a large amount of protein (26.3%), dietary fiber (27.5%), and fatty acids (33.2%), including linoleic, α-linolenic, and some amount of γ-linolenic acid. In our study, obese male Zucker rats (n = 6) at 8 weeks of age were supplemented for a further 4 weeks with either ground hemp seeds (12% diet) or lipid fractions in the form of hemp seed oil (4% diet). Hemp oil decreased blood plasma HDL-cholesterol (x0.76, p ≤ 0.0001), triglycerides (x0.55, p = 0.01), and calculated atherogenic parameters. Meanwhile, hemp seeds decreased HDL-cholesterol (x0.71, p ≤ 0.0001) and total cholesterol (x0.81, p = 0.006) but not the atherogenic index. The plasma antioxidant capacity of water-soluble compounds was decreased by the seeds (x0.30, p = 0.0015), which in turn was associated with a decrease in plasma uric acid (x0.18, p = 0.03). Dietary hemp seeds also decreased plasma urea (x0.80, p = 0.02), while the oil decreased the plasma total protein (x0.90, p = 0.05). Hemp seeds and the oil decreased lipid peroxidation in the blood plasma and in the heart (reflected as malondialdehyde content), improved contraction to noradrenaline, and up-regulated the sensitivity of potassium channels dependent on ATP and Ca2+. Meanwhile, acetylcholine-induced vasodilation was improved by hemp seeds exclusively. Dietary supplementation with ground hemp seeds was much more beneficial than the oil, which suggests that the lipid fractions are only partially responsible for this effect