Nutritional properties of mussels <Emphasis Type="Italic">Mytilus galloprovincialis</Emphasis>

The aim of this study was to determine the quality indices and assess the influence of diets supplemented with mussels from contaminated (MCont) and non-contaminated areas (MNCont) on some indices of protein and lipid metabolism in rats fed with cholesterol. A wide range of in vitro tests demonstrated that mussels from contaminated area have a higher content of proteins, lipids and higher antioxidant capability. In the in vivo experiment, 28 male Wistar rats were divided into 4 diet groups each of 7 and named Control, Cholesterol (Chol), Chol/MCont and Chol/MNCont. During 30 days of the experiment rats of all four groups were fed basal diet (BD), supplemented with 1% of Chol, 1% of Chol and 5.6% of mussel’s dry matter (DM) from contaminated and 1% Chol and 5.6% of mussel DM from non-contaminated areas for Chol/MCont and Chol/MNCont groups, respectively. At the end of the experiment, a high digestibility coefficient of DM and crude protein in the Chol/MCont and Chol/MNCont groups of rats was found: 93.56 and 93.87% and 91.64 and 91.36%, respectively, and the differences were not significant (P > 0.05). However, the protein efficiency ratio was significantly higher in the Chol/MCont and Chol/MNCont than in the Control and Chol diet groups. Also the level of nitrogen retention as shown by feces and urine examination was higher in the Chol/MCont and Chol/MNCont groups. Diet, supplemented with mussel dry matter from both contaminated and non-contaminated areas significantly hindered the rise in plasma lipids and also hindered the decrease in plasma antioxidant activity. Minor changes were fixed in the protein profile of rat’s plasma after both mussels’ diet. In conclusion, supplementation of diets, containing cholesterol with mussels’ DM from both contaminated and non-contaminated areas improves animals’ protein metabolism and positively affects plasma lipid profile and plasma antioxidant activity. Antioxidant tests can be used as an additional index for the quality of mussels.     

Effect of hesperidin and naringin on the plasma lipid profile and plasma antioxidant activity in rats fed a cholesterol‐containing diet

The objective of this study was to compare the influence of hesperidin and naringin, the main flavonones of orange and grapefruit, on plasma lipid profile and antioxidant activity in rats fed a cholesterol‐containing diet. Sixty male Wistar rats were randomly divided into six groups of 10, named Control, Hesperidin, Naringin, Chol, Chol/Hesperidin and Chol/Naringin. The Control group was fed a basal diet (BD) and 1–2 mL of distilled water. To the BD of the other five groups were added 0.1–0.2 mg of hesperidin dissolved in 1–2 mL of distilled water (Hesperidin group), 0.46–0.92 mg of naringin in 1–2 mL of water (Naringin group), 1% of non‐oxidised cholesterol (NOC) and 1–2 mL of water (Chol), 1% of NOC and 0.1–0.2 mg of hesperidin in 1–2 mL of water (Chol/Hesperidin), 1% of NOC and 0.46–0.92 mg of naringin in 1–2 mL of water (Chol/Naringin). After 30 days of the experiment it was found that the diets supplemented with hesperidin and naringin increased the plasma antioxidant activity. In conclusion, diets supplemented with hesperidin and naringin significantly hindered the increase in plasma lipid levels caused by cholesterol feeding. Hesperidin and naringin, bioactive compounds of citrus fruits, are powerful plasma lipid lowering and plasma antioxidant activity increasing flavonones. Copyright © 2007 Society of Chemical Industry     

Antioxidant properties and bioactive constituents of some rare exotic Thai fruits and comparison with conventional fruits: In vitro and in vivo studies

The aim of this research was to investigate the bioactivity of durian, snake fruit and mangosteen, rare exotic Thai fruits. These fruits were compared among them and with conventional fruits: durian with mango and avocado, and snake fruit with mangosteen and kiwifruit in order to find the preferable diet for human consumption. The contents of polyphenols, flavonoids, flavanols, tannins, anthocyanins, ascorbic acid and carotenoids, and the level of antioxidant potential by ABTS, DPPH, FRAP and CUPRAC in different extracts (methanol, water, acetone, and hexane) were determined. The presence of polyphenols (flavonoids and phenolic acids) in the investigated samples was characterized by Fourier transform infrared (FT-IR) spectroscopy and three-dimensional fluorimetry (3D-FL).The in vivo studies were carried out on 25 male Wistar rats, divided into 5 diet groups, each of 5. During 30 days of the experiment the rats of all 5 groups were fed basal diet (BD), which included wheat starch, casein, soybean oil, vitamin and mineral mixtures. The rats of the Control group were fed only the BD. The BD of the other 4 groups was supplemented with 1% of nonoxidized cholesterol (NOC) (Chol group), 1% of NOC in each group and 5% of lyophilized fruits: durian (Chol/Durian), snake fruit (Chol/Snake), mangosteen (Chol/Mangosteen). After the experiment diets supplemented with exotic fruits significantly hindered the rise in plasma lipids and hindered the decrease in the plasma antioxidant activity. In conclusion, the contents of bioactive compounds and the antioxidant potential are relatively high in the studied fruits and varied among them depending on the extraction procedure. FT-IR and 3D-FL can be used as additional tools for identification and comparison of bioactive compounds. Supplementation of diets with exotic fruits positively affects plasma lipid profile and antioxidant activity in rats fed cholesterol-containing diets.     

Bioactive properties of Snake fruit (Salacca edulis Reinw) and Mangosteen (Garcinia mangostana) and their influence on plasma lipid profile and antioxidant activity in rats fed cholesterol

Two exotic fruits (Snake fruit and Mangosteen) were characterized by polyphenols, proteins and antioxidant potentials and by their influence on plasma lipids and antioxidant activity in rats fed cholesterol. The content of polyphenols (14.9±1.5 and 9.2±0.8 mg GAE g⁻¹) and antioxidant potential (46.7±4.7 and 72.9±7.4 μmol TE g⁻¹) in Snake fruit was significantly higher than in Mangosteen (P<0.05). Twenty male Wistar rats were divided into four dietary groups: Control, Chol, Chol/Snake and Chol/Mangosteen. After 4 weeks of the experiment diets supplemented with Snake fruit and to a lesser degree with Mangosteen significantly hindered the rise in plasma lipids and hindered a decrease of antioxidant activity. Changes were found in fibrinogen fraction, such as solubility and mobility by the number of protein bands detected in SDS-electrophoresis: Chol/Snake differed from Chol/Mangosteen. In conclusion, Snake fruit and Mangosteen contain high quantity of bioactive compounds, therefore positively affect plasma lipid profile and antioxidant activity in rats fed cholesterol-containing diets. Such positive influence is higher in rats fed diet with added Snake fruit.     

Sugar beet pulp and apple pomace dietary fibers improve lipid metabolism in rats fed cholesterol

The effect of diets supplemented with sugar beet pulp fiber (SBP, 10%) and apple pomace fiber (AP, 10%) on lipids and lipids peroxides was investigated in 60 male Wistar rats. The rats were divided into six groups of 10 and adapted to cholesterol-free or 0.3% cholesterol diets. The basal diet (BD) contained wheat meal, barley meal, wheat hulls, meat-bone meal, barley sprouts, skimmed milk, fodder yeast, mineral and vitamin mixtures. The Control group (Control) consumed BD only. To the BD were added 3 g/kg cholesterol (Chol), 100 g/kg dry sugar beet pulp fiber (SBP), both 100 g/kg sugar beet pulp fiber and 3 g/kg cholesterol (SBP+Chol), 100 g/kg apple pomace fiber (AP), both 100 g/kg apple pomace fiber and 3 g/kg cholesterol (AP+Chol). The experiment lasted 40 days. Plasma total cholesterol (TC), LDL cholesterol (LDL-C), HDL cholesterol (HDL-C), triglycerides (TG), total phospholipids (TPH), HDL phospholipids (HDL-PH), lipid peroxides (LP) and liver TC concentration were measured. Groups did not differ before the experiment. In the Chol+SBP and the Chol+AP vs. Chol group the sugar beet pulp and apple pomace dietary fiber supplemented diet significantly (P<0.05) hindered the rise of plasma lipids: (a) TC−2.97 vs. 3.69 mmol/l, −20% and 3.01 vs 3.69 mmol/l, −18.4%, respectively; (b) LDL-C −1.36 vs. 2.02 mmol/l, −32.6% and 1.39 vs. 2.02 mmol/l, −31.2%, respectively; (c) TG −0.73 vs. 0.88 mmol/l, and 0.75 vs. 0.88 mmol/l; −17 and −14.8%, respectively, and TC in liver (17.1 vs. 24.3 μmol/g, −29.6% and 17.9 v. 24.3 μmol/g, −26.3%, respectively. Sugar beet and apple pomace fiber-supplemented diets significantly hindered the decrease in HDL-PH (0.79 vs. 0.63 mmol/l, −25.3%, P<0.025 and 0.75 vs. 0.63 mmol/l, −19%, P<0.05, respectively) and decreased the level of TPH (1.34 vs. 1.74 mmol/l, −23%, P<0.005 and 1.37 vs. 1.74 mmol/l, −21.3%, P<0.01, respectively). Both sugar beet pulp fiber and apple pomace fiber, in rats fed the basal diet without cholesterol, did not significantly affect the variables measured. Neither sugar beet pulp fiber or apple pomace fiber-supplemented diets influenced the level of lipid peroxides. These results demonstrate that sugar beet pulp fiber and to a lesser degree apple pomace fiber possess hypolipidemic properties. This is more evident when sugar beet pulp fiber or apple pomace fiber are added to the diet of rats fed cholesterol. The hypolipidemic effects of both sugar beet pulp fiber and apple pomace fiber can be attributed to their water-soluble parts. The sugar beet pulp and apple pomace fibers have no antioxidant properties.     

Plasma total,lipoprotein cholesterol,organs cholesterol and growth performance in rats fed dietary gum arabic

Thirty two male Wistar rats with initial body weight ranging from 45 to 55 g were randomly assigned to four dietary treatments. Rats were fed with ad libitum access diets containing 7.5% as cellulose or gum arabic with or without 1% added cholesterol for five weeks. Final body weight, body weight gain and feed efficiency ratio were comparable in all groups. Within cholesterol-fed groups, the cholesterol concentration of plasma was significantly lower in rats fed diet supplemented with gum arabic compared with those fed cellulose. Among cholesterol-fed groups, liver cholesterol was significantly higher in the group fed diet supplemented with gum arabic compared with those fed cellulose. In rats fed cholesterol-free diets, the cholesterol levels of plasma, LDL, HDL and liver were comparable.     

Coriander (<Emphasis Type="Italic">Coriandrum sativum</Emphasis> L.) seed oil improves plasma lipid profile in rats fed a diet containing cholesterol

Coriander (Coriandrum sativum L.) seed oil (COR) is a promising oil with high levels of bioactive compounds. Very little information, however, is available on the effect of administration of COR on different aspects of plasma lipid profile in experimental animals. In view of the important implications, the effect of administration of COR and oil blend [a mixture of soybean oil, coriander oil and sunflower oil (4:2:4, w/w/w; Blend)] on the profile of plasma lipids was investigated in 24 male albino rats placed on a cholesterol-rich (1%) basal diet as compared to rats on a cholesterol-free basal diet. Coriander seed oil and Blend were analyzed for composition of fatty acid, sterol and tocopherol. The levels of bioactive compounds (sterols and tocopherols) were higher in COR than in the Blend. In addition, the antiradical potential of COR and Blend was measured and the results showed that COR had stronger radical scavenging activity than Blend. In the biological experiment, rats were divided into four diet groups. The negative control group (control) consumed the basal diet (BD) only, which contained wheat starch, casein and cellulose, as well as mineral and vitamin mixtures. To the BD were added 1 g/100 g cholesterol (Chol/group), or both (Chol/COR group) and (Chol/Blend group). The groups did not differ before the experiment, which lasted 60 days. Plasma total lipids (TL), triacylglycerols (TAG), total cholesterol (TC), low-density lipoprotein-cholesterol (LDL-C) and high-density lipoprotein-cholesterol (HDL-C) were measured at day 15, 30, 45 and 60 during the experiment period. Generally, COR and Blend-supplemented diets decreased the levels of TL, TC, TAG and LDL-C in plasma. In addition, significant increase in the levels of HDL-C was observed for Chol/COR and Chol/Blend groups. The results demonstrated that COR, and to a relatively lesser degree Blend, have hypocholesterolemic properties in rats fed a cholesterol-rich diet.     

Two exotic fruits positively affect rat’s plasma composition

The aim of this investigation was to determine the bioactive compounds and the antioxidant potentials of Snake fruit and Mangosteen and their influence on plasma lipid levels and antioxidant activity in rats fed cholesterol-containing diets. It was found that total polyphenols and antioxidant potentials of Snake fruit were significantly higher than those of Mangosteen (P < 0.05). A cholesterol-containing diet supplemented with the studied exotic fruits showed a positive affect on rat’s plasma lipid levels and on the antioxidant activity during 30 days of feeding. In rat’s plasma of the Chol/Snake diet group, the fibrinogen fraction showed a decrease in the amounts and compositions of electrophoretic protein bands in the range of 110 and 14 kDa. However, all the positive results of this experiment on animals could not be automatically applied to humans.     

Hypocholesterimic effects of cold and hot extracted virgin coconut oil (VCO) in comparison to commercial coconut oil: Evidence from a male wistar albino rat model

The hypolipidemic effect of cold extracted virgin coconut oil (CEVCO) and hot extracted virgin coconut oil (HEVCO) compared to commercially available coconut oil (CCO) was studied using male wistar rats. Groups were designated as control, hypercholesterimic control (HC Control), HC+10% (CEVCO), HC+15% (CEVCO), HC+10% (HEVCO), HC+15% (HEVCO) and HC+15% (CCO). Control rats were fed a basal diet while other groups were initially fed a hypercholesterimic diet (2% cholesterol and 0.25% bile salts) for 15 days, then fed with CEVCO or HEVCO (both at 10% and 15% levels), and commercial coconut oil (15%) for 30 days. Total cholesterol and LDL cholesterol levels were significantly (p<0.05) decreased by approximately 25 and 40%, respectively, in the blood plasma, while HDL cholesterol increased significantly (p<0.05) by approximately 21% in HEVCO fed rats. Tissue cholesterol and triacylycerol (TAG) levels in both liver and heart tissues decreased significantly (p<0.05) in CEVCO and HEVCO fed animals, compared with CCO fed rats.     

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.     

Influence of bioflavonoids from the radix extract of Scutellaria baicalensis on the level of serum lipids, and the development of laboratory rats fed with fresh and oxidized fats

The aim of this study was to assess the influence of bioflavonoids from the radix of Scurellaria baicalensis on the level of lipids, via the determination of the concentrations of triglycerides, total cholesterol and high-density lipoprotein (HDL) cholesterol in the plasma of laboratory rats fed high-fat and high-cholesterol diets, and via the calculation of their atherogenic index. We also studied the influence of bioflavonoids on their physical development by measuring the increase in their body mass and liver mass. The rats were fed a diet with a 15% content of fresh or oxidized lard or sunflower oil, along with 0.5% added cholesterol. 0.05% S. baicalensis radix extract was added to the diet of half of the rats as the source of bioflavonoids. In the group of rats fed a diet containing oxidized oil we observed a significantly lower increase in body mass (15.5 +/- 7.6 g/4 weeks/rat) than that observed for the control rats (77.0 +/- 15.7 g/4 weeks/rat). The addition of S. baicalensis radix extract to the diet raised the increase in body mass in the groups receiving oil as the source of fat; those receiving fresh oil had a 40% increase, and those receiving oxidized oil showed a 300% increase relative to the appropriate controls. In all the groups of rats fed a diet with bioflavonoids added, a beneficial decrease in the plasma triglyceride content was observed relative to the appropriate controls. In the plasma of rats on a diet containing the extract and fresh or oxidized oil or fresh lard, we observed a beneficial reduction in the total cholesterol level relative to the appropriate controls. The atherogenic index was higher for the group of animals fed with fresh lard than for those fed with fresh oil, and higher for those fed with oxidized oil than for those fed with oxidized lard. The addition of bioflavonoids to the diet beneficially reduced the atherogenic index value in the group fed with fresh oil, and increased its value in the group fed with oxidized lard.     

Effect of grape seed oil supplementation on plasma lipid profiles in rats

The purpose of the study was to investigate the comparative effects of feeding of grape seed oil (GSO), soybean oil (SO), and lard on plasma lipid profile in rats. Lard fed diets increased body weight gain in rats and resulted in negative effects on lipoprotein metabolism. However, the GSO fed rats had a significant reduction in total cholesterol (TC, 60.6 mg/dL), low density lipoprotein cholesterol (LDLC, 16.8 mg/dL), and atherogenic index (AI, 0.9), and the ratio of high density lipoprotein cholesterol (HDLC) to TC (0.5) was significantly higher than those of SO and lard groups. These data suggest that GSO supplementation has significant health benefits through favorable alterations in plasma lipid profiles compared to SO and lard fed rats. GSO may be good dietary oil and may provide health benefits in hyperlipidemia and related complications.     

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.     

Effects of casein,sweet white lupin and sweet yellow lupin diet on cholesterol metabolism in rats

The effect of lupin seed protein on rat cholesterol metabolism has been studied with diets high in fat (20% by weight) and containing cholesterol (1%). The proteins used were characterised by their lysine/arginine ratios (sweet white lupin (SWL) 0·5; sweet yellow lupin (SYL) 0·4; and casein 1·8), because the lysine/arginine ratio is one of the parameters suspected to decrease or increase plasma cholesterol depending on the ratio; the diets were also characterised by their total fibre content (casein diet 5%; SWL 22%; SYL 17%) because chronic fibre intake could improve glucose tolerance and modify glucoregulatory hormone levels. Methionine content of diets was balanced. Differences among the total serum cholesterol levels of rat groups fed these diets for 28 days were not significant. But, compared to the casein diet, both lupin diets increased plasma glucagon levels and faeces. Compared to casein and SYL diets, the SWL diet significantly decreased plasma triglyceride levels and the insulin/glucagon ratio, as well as unesterified liver cholesterol and plasma LDL triglycerides levels. The SYL diet significantly increased plasma glucose and insulin, as well as liver total cholesterol compared to the casein and SWL diets. The total fibre content of the diets could indirectly modulate the effect related to the insulin/glucagon ratio on cholesterol metabolism and explain the differences observed between the SWL and SYL diets. © 1998 SCI.     

Antioxidant and antithrombotic effects of green mussels (Perna canaliculus) in rats

In the past decade, the use of marine mussels as seafood is being more popular. They considered being a rich source of various nutritional bioactive compounds that aroused the scientific community's interest. This study investigated the antioxidant and the antithrombotic consequences on Sprague-Dawley male rats after adding dried New Zealand mussel Perna canaliculus in their diet. The biochemical, hematological and histopathological changes were also observed. Forty rats were divided into four groups according to the amount of dried mussels in their diet, in addition to a control group that consumed a basal diet only. Group 1 consumed 25% dried mussels in its basal diet; Group 2 consumed 35% dried mussels in its basal diet, and Group 3 was consumed 45% dried mussels in its basal diet. The biochemical parameters showed improvements in liver function. Interestingly, the lipid profile decreased, especially the low-density lipoprotein cholesterol (LDL-C) levels which were reduced significantly in Group 3 (p < .01). These observations were accompanied by a decrease in iron levels significantly as the amount of dried mussels increased (p < .01). Furthermore, the noticed changes in the hematological profile prove that there is an increase in antithrombotic activity. Dried mussels had potent antioxidant effects in the liver as shown by increased lipid peroxide (p < .05), reduced glutathione (p < .05), and glutathione peroxidase (GSH-Px; p < .05). Additionally, antioxidant activity in the kidney was shown to increase through GSH-Px activity (p < .01). In conclusion, these results indicate that consuming dried mussels resulted in improved biochemical and antioxidants activities and could be used as an antithrombotic agent.     

Intact pectin and its polygalacturonic acid regions have similar hypocholesterolemic properties in hybrid F1B hamsters

We fed cholesterol-enriched (0.1% w/w) semipurified diets containing 3% of lemon pectin or 3% of the polygalacturonic acid regions fraction (smooth regions fraction) of the lemon pectin to hybrid F1B hamsters for a period of 8 weeks. A control group was fed cellulose and a positive control group was fed psyllium. The feeding of the semipurified diets resulted in an increase of plasma cholesterol levels in all the dietary groups when compared with initial values. The hamsters fed the psyllium, pectin, or the polygalacturonic acid regions fraction had significantly (P < 0.05) lower plasma cholesterol levels than the cellulose fed group throughout the experimental period. Plasma cholesterol levels in the hamsters fed the psyllium, pectin, or polygalacturonic acid regions fraction were not significantly different. Liver cholesterol concentrations were also lower in the hamsters fed the psyllium, pectin, or the polygalacturonic acid regions fraction than in the hamsters fed the cellulose, but this effect reached statistical significance only in the hamsters fed the polygalacturonic acid regions fraction. The results of these studies suggest that the polygalacturonic acid regions of the pectin molecule is responsible for the cholesterol-lowering properties of the pectin.     

8-HYDROXY-2'DEOXYGUANOSINE LEVELS AND ANTIOXIDANT STATUS IN RAT LIVER FED WITH OLIVE AND CORN OIL DIETS: EFFECT OF ASCORBIC ACID SUPPLEMENATION

DNA damage and antioxidants status were determined in liver of rat fed with olive and corn oil diets with and without ascorbic acid supplementation. In order to elucidate the role of fat intake, the study included a control and hyperlipidic diet. Liver antioxidant activities were significantly influenced by dietary fat and intake levels. In general, control groups fed with corn oil diets exhibited reduced liver antioxidant (SOD, catalase, and GSH-PX) and GSH levels compared with rats fed on olive oil diets. These activities were lower in rats consuming hyperlipidic diets relative to the control groups. Ascorbic acid supplementation resulted in a slight decrease of antioxidant activities both in the control and hyperlipidic diets with the exception of GSH that showed high levels in rats fed on an olive oil diet supplemented with ascorbic acid. The results of oxidative DNA damage as measured by the induction of 8-hydroxy deoxyguanosine (8-OHdG) clearly confirmed that corn diet (rich in polyunsaturated fatty acids) induced DNA damage in a dose- dependent manner. No induction of 8-OHdG was detected for the diet containing olive oil (monounsaturated diet). Ascorbic acid had no effect on rat fed on an olive oil diet. In contrast, for corn diets the ascorbic acid showed     

Choosing hamsters but not rats as a model for studying plasma cholesterol‐lowering activity of functional foods

Rats and hamsters are commonly used rodents to test the efficacy of cholesterol‐lowering functional foods. In general, a diet containing 1% cholesterol for rats whereas a diet containing 0.1% cholesterol for hamsters is used to induce the hypercholesterolemia. The present study was carried out to compare hamsters with rats as a hypercholesterolemia model. Golden Syrian hamsters and Sprague Dawley rats were randomly divided into four groups and fed one of the four diets containing 0–0.9% cholesterol. Results demonstrated that serum total cholesterol (TC) in hamsters was raised 73–81% higher than that in rats fed the same cholesterol diets. Unlike rats in which HDL‐C accounted very little for serum TC, the lipoprotein profile in hamsters was closer to that in humans. We investigated interaction of higher cholesterol diets with 3‐hydroxy‐3‐methylglutary‐CoA (HMG‐CoA) reductase, low‐density lipoprotein receptor (LDL‐R) and cholesterol‐7α‐hydroxylase (CYP7A1), sterol regulatory element binding protein‐2 (SREBP‐2), and liver X receptor (LXR‐α). Results showed hamsters and rats metabolized cholesterol differently. In view that hamsters synthesize and excrete cholesterol and bile acids in a manner similar to that in humans, it is concluded that hamsters but not rats shall be chosen as a model to study efficacy of cholesterol‐lowering functional foods.     

Polysaccharides from the green alga Ulva rigida improve the antioxidant status and prevent fatty streak lesions in the high cholesterol fed hamster,an animal model of nutritionally-induced atherosclerosis

We investigated the effects of Ulva in hypercholesterolemic hamsters, before and after processing. Three groups of 12 hamsters were fed a high cholesterol diet for 12 wk (Control) or a high cholesterol diet where cellulose has been replaced for an equivalent fibre weight from Ulva or processed Ulva. Plasma cholesterol, non-HDL cholesterol and specially triglycerides were reduced by Ulva. Liver glutathione peroxidase activity was increased and thiobarbituric acid reactive substances were efficiently reduced by dietary treatments compared with controls, whereas plasma antioxidant capacity was increased and aortic fatty streak area was decreased by 70%. The results show for the first time that chronic consumption of polysaccharides supplied by Ulva prevent the fall of antioxidant defences and the development of atherosclerosis in hamsters. The underlying mechanism is related mainly to increased antioxidant status although improvement of the serum lipid profile was not ruled out.     

Effects of diet supplementation with cactus pear seeds and oil on serum and liver lipid parameters in rats

The purpose of this investigation was to evaluate the effects of diets enriched with cactus pear oil (CPO) or seeds (CPS) on serum and liver lipid parameters compared to those of adult rats submitted to a standard diet. Male rats were divided into three groups, the first group represented control group, fed with standard diet, the second group was fed with control diet supplemented with CPO (2.5%, wt/wt) and the third group fed control diet supplemented with CPS (33%, wt/wt), for nine weeks. Feed intake and body weight of rats were measured every two days. Organ weights were determined at the end of treatment; cholesterol, HDL and triglycerides levels were determined by enzymatic methods. Liver and serum lipid extracts were analysed for their fatty acid composition for the three groups of rats. No differences in pancreas, kidney or liver weights were observed in the CPS diet whereas the CPO diet induced a significant increase in liver and pancreas weights. The tested diets significantly decreased the atherogenic index compared to the control diet, whereas serum cholesterol level was only reduced by the supplementation with CPO diet. No variations in serum lipids were observed among the groups, whereas liver lipids showed slight variations. Accordingly, these results indicated that the supplementation with CPO or CPS could be effective in decreasing the atherogenic risk factors in rats.