FISH OIL WITH ESSENCE OF CHICKEN DECREASES SERUM AND HEPATIC TRIACYLGLYCEROL IN HAMSTERS FED AN ATHEROGENIC DIET

The aim of the present study was to investigate the effect of a mixture of dietary chicken essence and fish oil on possible lowering of blood and hepatic lipids in hamsters. Forty male hamsters were randomly divided into four groups and fed a chow diet, high fat/cholesterol diet (HFC), HFC diets containing 4% (HFC4) or 8% (HFC8) fish oil with essence of chicken for 42 days. The experimental diets contained 10% (w/w) fat. Hamsters fed HFC diets containing either 4 or 8% fish oil with essence of chicken showed significantly decreased serum triacylglycerols (TG) compared to hamsters fed HFC diets. In addition, hamsters fed HFC8 diets exhibited significantly reduced hepatic TG than those fed HFC diet. However, hamsters fed HFC4 or HFC8 diets significantly increased low density lipoprotein cholesterol (LDL-C) and decreased high density lipoprotein cholesterol (HDL-C) when compared with those on HFC diet. These results suggest that 4% (or more) fish oil with essence of chicken might significantly lower serum TG and hepatic TG in hamsters, but seem to increase serum cholesterol levels on HFC diets.     

Hypocholesterolemic Action of Fermented Brown Rice Supplement in Cholesterol-Fed Rats: Cholesterol-lowering Action of Fermented Brown Rice

Fermented rice products have been implicated in vascular injury and atherosclerosis in recent animal and human studies. In the current study, whether consumption of differently processed brown rice diets may change the cholesterol metabolism was evaluated in male Spraque Dawley (SD) rats after 28 d of treatment with diets containing 1% cholesterol. The experimental diets include corn starch alone as control diet (CO) or a diet containing a 50% substitute of CO; uncooked brown rice (UB), cooked brown rice (CB), lactic acid bacteria (LAB), brown rice mixed with LAB (BLAB), and fermented‐brown rice by LAB (FB), respectively. Among them, FB group elicited significantly lower levels of plasma and hepatic triglycerides, plasma total cholesterol, low‐density lipoprotein cholesterol (LDL‐C), and very low‐density lipoprotein cholesterol (VLDL‐C) by 33% to 50%, whereas higher levels of HDL‐C were elicited by 227% compared with the CO group (P < 0.05). These amelioration action on lipid profile in FB group appeared to correspondent to the higher excretions of fecal weight, triglyceride (TG), total cholesterol (TC), and bile acid (P < 0.05). Furthermore, sensory properties such as flavor liking, taste liking, and overall acceptability of the diet were significantly improved by the addition of fermented brown rice. Conclusively, fermented‐brown rice may have a potent cholesterol‐lowering benefits with sensory quality improvement of the diet.     

Hypolipidemic Activity of Peony Seed Oil Rich in α‐Linolenic,is Mediated Through Inhibition of Lipogenesis and Upregulation of Fatty Acid β‐Oxidation

Peony seed oil (PSO) is a new resource food rich in α‐Linolenic Acid(ALA) (38.66%). The objective of this study was to assess the modulatory effect of PSO on lipid metabolism. Lard oil, safflower oil (SFO), and PSO were fed to wistar rats with 1% cholesterol in the diet for 60 d. Serum and liver lipids showed significant decrease in total cholesterol (TC), triglyceride (TG), and low density lipoprotein‐cholesterol (LDL‐C) levels in PSO fed rats compared to lard oil and SFO fed rats. ALA, eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA), contents were significantly increased, whereas linoleic acid (LA), arachidonic acid (AA) levels decreased in serum and liver of PSO fed rats. Feeding PSO increased ALA level and decreased n‐6 to n‐3 polyunsaturated fatty acid (PUFA) ratio. The hypolipidemic result of PSO indicated that PSO participated in the regulation of plasma lipid concentration and cholesterol metabolism in liver. The decreased expression of sterol regulatory element‐binding proteins 1C (SREBP‐1c), acetyl‐CoA carboxylase (ACC), and fatty acid synthase (FAS)‐reduced lipid synthesis; Activation of peroxisome proliferator–activator receptor (PPARα) accompanied by increase of uncoupling protein2 (UP2) and acyl‐CoA oxidase (AOX) stimulated lipid metabolism and exerted an antiobesity effect via increasing energy expenditure for prevention of obesity.     

Dietary calcium decreases plasma cholesterol by down‐regulation of intestinal Niemann–Pick C1 like 1 and microsomal triacylglycerol transport protein and up‐regulation of CYP7A1 and ABCG 5/8 in hamsters

Scope: It has been shown that calcium supplementation favorably modifies plasma lipoprotein profile in postmenopausal women. The present study investigated the interaction of dietary calcium with genes of transporters, receptors and enzymes involved in cholesterol metabolism. Methods and results: Forty‐eight ovariectomized hamsters were fed one of the four diets containing 0, 2, 6 and 8 g calcium per kg. Plasma total cholesterol (TC), triacylglycerols (TG), and non‐high density lipoprotein cholesterol were dose‐dependently decreased, whereas high‐density lipoprotein cholesterol (HDL‐C) was dose‐dependently increased with the increasing dietary calcium levels. Dietary calcium had no effect on protein mass of hepatic sterol regulatory element binding protein‐2 (SREBP), liver X receptor‐alpha (LXR), 3‐hydroxy‐3‐methylglutaryl‐CoA reductase (HMGR), LDL receptor (LDLR) and cholesterol‐7α‐hydroxylase (CYP7A1). However, dietary calcium up‐regulated the mRNA levels of hepatic CYP7A1 and intestinal ATP binding cassette transporters (ABCG5/8) whereas it down‐regulated the intestinal Niemann‐Pick C1 like 1 (NPC1L1) and microsomal triacylglycerol transport protein (MTP). In addition, dietary calcium increased the activity of intestinal acyl coenzyme A: cholesterol acyltransferase 2, while it decreased plasma cholesteryl ester transport protein (CETP). Conclusion: Beneficial modification of lipoprotein profile by dietary calcium was mediated by sequestering bile acid absorption and enhancing excretion of fecal cholesterol, via up‐regulation of mRNA CYP7A1 and intestinal ABCG 5/8 with down‐regulation of mRNA NPC1L1 and MTP.     

四株益生菌对高脂血症仓鼠降血脂作用的研究

目的:观察不同益生菌菌株对实验性高脂血症仓鼠脂代谢的影响。方法:利用高脂饲料诱导仓鼠高脂血症模型,给仓鼠灌胃益生菌菌液,测定血清总胆固醇(TC)、甘油三酯(TG)、高密度脂蛋白胆固醇(HDL-C)的含量及肝脏组织中TC、TG的含量。结果:四株益生菌均可有效降低高脂膳食仓鼠血清TC、TG、非高密度脂蛋白胆固醇(non-HDL-C)含量及动脉粥样硬化指数(AI)值,提高HDL-C含量,还可以显著降低肝脏中TC、TG含量。结论:四株益生菌均能有效改善仓鼠血脂代谢,预防和减少动脉粥样硬化的发生。鼠李糖乳杆菌降低高脂饮食仓鼠血清TC、TG含量的作用最强,嗜酸乳杆菌、鼠李糖乳杆菌升高血清HDL-C含量的作用最强,但嗜酸乳杆菌降低肝脏中TC含量的作用最强。     

Feeding Tomatoes to Hamsters Reduces their Plasma Low-density Lipoprotein Cholesterol and Triglycerides

Hamsters were fed semipurified diets containing green or red freeze‐dried tomato powders. Compared to the control diet devoid of tomatoes, a 59% and 44% reduction low‐density lipoprotein (LDL) cholesterol was induced by both the green and red tomatoes, respectively. The corresponding reductions in very low‐density lipoproteins (VLDL) were 45% and 35% and in plasma triglyceride concentrations 47% and 31%, respectively. Plasma levels of high‐density lipoproteins (HDL) were unaffected. Fecal deoxycholic and lithocholic acid concentrations of hamsters on tomato diets were higher than those on control diets. Possible contributions of major components of green and red tomatoes to these beneficial effects are discussed.     

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.     

Goldenberry (Physalis peruviana) Juice Rich in Health‐Beneficial Compounds Suppresses High‐Cholesterol Diet‐Induced Hypercholesterolemia in Rats

Goldenberries (Physalis peruviana) are a promising exotic fruit that could be a subject of many novel foods. No reports are available on the effect of administration of goldenberries on different aspects of blood profile in experimental animals. The objective of this study was to investigate the effect of feeding goldenberry juice on hypercholesterolemia by analyzing the changes in the blood profile of high‐cholesterol diet (HCD)‐fed rats. The chemical composition and antiradical properties of juice were determined. Generally, rats fed with goldenberry juice showed lower levels of total cholesterol, total triacylglycerol and total low‐density lipoprotein cholesterol, as well as higher levels of high‐density lipoprotein cholesterol in comparison with animals fed with HCD and cholesterol‐free diet. Juice administration induced a decrease in the activity of glutamic pyruvic transaminase compared with the positive control group after 2 months of administration. There was a remarkable decrease in total serum protein, albumin and globulin for groups treated with goldenberry juice. Histological examination of the liver and kidney were also conducted. The results demonstrated that consumption of goldenberry juice may provide beneficial effects on reversing HCD‐associated detrimental changes.     

Metabolic response of soy pinitol on lipid‐lowering,antioxidant and hepatoprotective action in hamsters fed‐high fat and high cholesterol diet

This study was performed to investigate the lipid‐lowering, antioxidant, and hepato‐protective effects of pinitol in dose‐dependent manners in hamsters fed‐high fat and high cholesterol (HFHC) diet. Pinitol supplementation (0.05%, P‐I and 0.1% pinitol, P‐II) with an HFHC diet (10% coconut oil plus 0.2% cholesterol) for 10 wks significantly lowered the white adipose tissue weights, hepatic lipid droplets, plasma glucose, total‐cholesterol, nonHDL‐cholesterol, total‐cholesterol/HDL‐cholesterol ratio, and hepatic lipid levels. Whereas it significantly increased the brown adipose tissue weight, plasma HDL‐cholesterol, apolipoprotein A‐I (apo A‐I) concentrations, paraoxonase (PON) activity, and/or mRNA expression, compared to the HFHC control group. Plasma insulin and adiponectin levels were significantly lower and higher, respectively, in both P‐I and P‐II groups than the HFHC control group. Dietary pinitol significantly inhibited hepatic HMG‐CoA reductase, acyl‐CoA:cholesterol acyltransferase (ACAT), and cytochrome P4502E1 (CYP2E1) activities without altering their mRNA expressions compared to the control group. Pinitol significantly elevated the hepatic antioxidant enzyme activities, whereas it also significantly reduced the hepatic lipid peroxide and H₂O₂ production. Accordingly, these results indicate that both 0.05 and 0.1% pinitol supplementation may improve the lipid and antioxidant metabolism in HFHC diet‐fed hamsters. In particular, pinitol supplementation was very effective on the elevation of antiatherogenic factors, including plasma HDL‐cholesterol, apo A‐I, adiponectin, and PON.     

Hypocholesterolaemic effect of yoghurt containing Bifidobacterium pseudocatenulatum G4 or Bifidobacterium longum BB536

The effect of a yoghurt supplement containing Bifidobacterium pseudocatenulatum G4 or Bifidobacterium longum BB536 on plasma lipids, lipid peroxidation and the faecal excretion of bile acids was examined in rats fed a cholesterol-enriched diet. After 8 weeks, the rats in the positive control (PC) group who were fed the cholesterol-enriched diet showed significant increases in plasma total cholesterol (TC), low-density lipoprotein (LDL) cholesterol, and malondialdehyde (MDA). However, groups fed a cholesterol-enriched diet supplemented with yoghurt containing B. pseudocatenulatum G4 or B. longum BB536 had significantly lower plasma TC, LDL-C, very-low-density lipoprotein (VLDL) cholesterol, and MDA than had the PC group after 8 weeks of treatment. In addition, faecal excretion of bile acids was markedly increased in the rats fed the yoghurt containing B. pseudocatenulatum G4 or B. longum BB536 as compared to the PC and NC groups.     

Effect of Dietary Partial Hydrolysate of Phospholipids,Rich in Docosahexaenoic Acid‐Bound Lysophospholipids,on Lipid and Fatty Acid Composition in Rat Serum and Liver

Lysophospholipids have been recognized as potent biologically active lipid mediators. However, attention has not been paid to the health benefits of dietary partial hydrolysate of phospholipids (PH‐PL), which is rich in docosahexaenoic acid (DHA)‐bound lysophospholipids. In this study, the effects of PH‐PL on serum and liver lipid profiles of rats upon administration of PH‐PL are demonstrated in comparison to those of fish oil (FO), which comprises eicosapentaenoic acid (EPA) and DHA‐bound triglyceride (TG). PH‐PL containing EPA and DHA was prepared via enzymatic modification of squid (Todarodes pacificus) meal that is rich in phospholipids. Male Wistar rats were fed a basal diet containing soybean oil alone (7%), FO, and PH‐PL. The FO and PH‐PL diets had similar EPA and DHA contents. After the rats had been fed their respective diets for 28 d, their serum and liver lipid contents, fecal lipid excretion, and hepatic gene expression level were measured. The results demonstrated that compared with the soybean oil diet alone, the PH‐PL diet decreased serum and liver TG contents partially because of the enhancement of liver acyl‐CoA oxidase activity and suppression of liver fatty acid synthase activity. In addition, compared with the soybean oil diet, the PH‐PL group exhibited lower serum cholesterol content at least in part because of the reduction of hepatic 3‐hydroxy‐3‐methylglutaryl‐CoA reductase mRNA expression level. We found that dietary administration of EPA and DHA containing PH‐PL has a hypolipidemic effect that may help prevent the development lifestyle‐related diseases.     

Hypocholesterolemic activity of onion is mediated by enhancing excretion of fecal sterols in hamsters

Onion has been shown to favorably modify the lipoprotein profile. However, research on its underlying mechanism is lacking. The present study investigated the interaction of dietary onion powder with the protein expression of key receptors and enzymes involved in cholesterol metabolism. Thirty-six male hamsters were randomly divided into three groups and fed a high-cholesterol control diet or the two experimental diets supplemented with 1% onion powder (OP-1) or 5% onion powder (OP-5), for a period of 8 weeks. It was found that onion dose-dependently decreased plasma total cholesterol (TC) level. The change in plasma lipoprotein profile was accompanied by a greater excretion of both fecal neutral and acidic sterols. Western blot analysis revealed that onion up-regulated sterol regulatory element binding protein 2 (SREBP-2), liver X receptor alpha (LXRα) and cholesterol-7α-hydroxylase (CYP7A1) with no effect on 3-hydroxy-3-methylglutaryl-CoA reductase (HMGR) and LDL receptor (LDL-R). It was concluded that the hypocholesterolemic activity of onion powder was mediated by enhancement of fecal sterol excretion and up-regulation of LXRα and CYP7A1.     

Antihyperlipidemic effect of sesame (Sesamum indicum L.) protein isolate in rats fed a normal and high cholesterol diet

The dietary influence of sesame protein isolate (protein content 91.5%), produced from dehulled, defatted sesame meal, on blood and tissue lipid profile and lipid peroxidation has been assessed in normal and hypercholesterolemic rats. To evaluate their hypocholesterolemic and antioxidative activity in vivo, we fed 18% sesame protein isolate with or without 2% cholesterol in comparison with casein to rats for 28 d. We determined plasma total protein, total cholesterol, high-density lipoprotein (HDL)-cholesterol, low-density lipoprotein (LDL)-cholesterol, triacylglycerol as well as susceptibility of plasma and erythrocyte membrane lipid to oxidation ex vivo. Liver tissue lipid, cholesterol, phospholipids, and lipid peroxidations were also determined. The total cholesterol, LDL-cholesterol and triacylglycerol levels were significantly reduced in the sesame protein isolate and isolate containing cholesterol group than the corresponding control casein groups. HDL-cholesterol level was also increased in sesame protein isolate (41%) and protein isolate containing cholesterol group (38%) than the corresponding control casein and casein containing cholesterol groups. There was 49% and 64% lowering of plasma lipid peroxidation as well as 36% and 56% lowering of lipoprotein oxidation susceptibility (LOS) in the 2 experimental groups (sesame protein isolate and isolate containing cholesterol group) than the corresponding control (casein and casein containing cholesterol) groups. There was significant lowering of erythrocyte membrane lipid peroxidation (68% and 63% lowering in sesame protein isolate and isolate containing cholesterol groups) and liver lipid peroxidation (61% and 76% lowering in the 2 experimental groups than the corresponding control casein groups). Therefore, our results indicate that sesame protein isolate decreases cholesterol concentration in plasma, increases HDL-cholesterol, and also decreases plasma and erythrocyte membrane lipid peroxidation with or without cholesterol fed diet in rats.     

Hypolipidemic and hypoglycemic potential of raw,boiled, and sprouted mung beans (Vigna radiata L. Wilczek) in rats

This study was carried out to investigate the hypolipidemic and hypoglycemic potential of raw, boiled, and sprouted mung beans in rats. Oven dried mung bean powders; raw, sprouted, and boiled were included at 30% level in the diet of seven weeks old male Wistar rats maintained for 5 weeks on high (0.5%) cholesterol diet in comparison with control diet. Low serum glucose and triglyceride concentrations (p < .05) in raw and processed mung bean diets fed rats were supported by low serum insulin level in both raw mung bean diet and boiled mung bean diet fed rats. Hypoglycemic effect in sprouted mung bean fed rats was supported by higher α‐amylase inhibitory activity and α‐glucosidase inhibitory activity of sprouted mung beans. Increase in serum non‐HDL cholesterol concentration and decrease in HDL cholesterol concentration caused by high cholesterol diet were modulated (p < .05) by both boiled and sprouted mung bean diets.

Practical applications

Mung bean is a green legume rich in protein, fiber, antioxidants, and phytonutrients. Hypocholesterolemic and hypoglycemic potential of raw mung beans have been shown previously. It is well known that cooking and processing modulate nutritional and biochemical parameters of foods. However, very limited information is available on the effect of processing on functional properties of legumes. Results of this study showed that boiling and sprouting improved the soluble fiber content and hypocholesterolemic potential of mung beans. Thus, the processed mung beans may be more suitable for developing food supplements for patients with hypercholesterolemia.     

发酵麦胚对高脂模型大鼠胆固醇水平的调节

目的:探讨发酵麦胚对高脂模型大鼠胆固醇水平的调节及可能的作用机制。方法:雄性SD大鼠,根据体质量和血清胆固醇水平随机分组,每组10只,空白组自由取食基础饲料和饮水,模型组、液低组、液中组、液高组、渣低组、渣中组、渣高组自由取食高脂饲料和饮水,每天固定时间灌胃,空白组和模型组灌胃同体积水,其他组分别灌胃221、442、884 mg/(kg·d)的发酵液冻干粉和沉淀物冻干粉。60 d后测血清总胆固醇(total cholesterol,TC)含量、高密度脂蛋白胆固醇(high density lipoprotein cholesterol,HDL-C)含量、肝脏TC含量、胆固醇7α-羟化酶(cholesterol 7α-hydroxylase,CYP7A1)活性、排便量和粪便胆汁酸含量。结果:模型组血清TC含量极显著高于空白组(P0.01),高胆固醇血症模型构建成功;液低组、渣中组大鼠血清TC含量分别显著(P0.05)和极显著(P0.01)低于模型组;各受试组肝脏TC含量、排便量和粪便胆汁酸排出量均高于模型组,但未达显著水平(P0.05)。结论:发酵麦胚降血清胆固醇效果明确,且具有时间效应和剂量效应关系;其作用途径可能与促进血清胆固醇向肝脏转运、增加胆固醇向胆汁酸转化以及增加排便量有关。     

EFFECTS OF ORAL CHONDROITIN SULFATE ON LIPID AND ANTIOXIDANT METABOLISMS IN RATS FED A HIGH-FAT DIET

This study aimed at determining the effects of purified chondroitin sulfate (ChS) from pig laryngeal cartilage on the lipid and antioxidant metabolisms of male Sprague‐Dawley rats that are fed a high‐fat diet. Thirty‐two male rats were divided into four groups and fed for 5 weeks on a standard diet, a high‐fat diet or a high‐fat diet plus ChS. It was demonstrated that the high‐fat diet provoked lipid peroxidation and induced a severe depletion of lipoprotein lipase, hepatic lipidase, glutathione, catalase and superoxide dismutase levels. ChS was effective in reducing triglycerides, total cholesterol, low‐density‐lipid cholesterol and malondialdehyde levels elevated by the high‐fat diet. In addition, ChS might reduce the risk of atherosclerosis, as high‐density‐lipid cholesterol, lipoprotein lipase, hepatic lipidase and the ratio of high‐density‐lipoprotein cholesterol to total cholesterol were significantly higher than in the high‐fat‐diet rats. ChS restored the endogenous antioxidants glutathione, catalase and superoxide dismutase. These results showed that ChS was potent in lipid‐lowering and altering the antioxidative enzyme; however, excess ChS would disturb lipid profiles that went beyond the normal limits.     

Cholesterol-lowering effect of phytosterol-containing lactic-fermented milk powder in hamsters

Male hamsters were fed six different diets for 4 weeks. Group 1, fed with control diet of regular rodent chow. Group 2, fed with high-fat-high-cholesterol diet containing cholesterol and corn/coconut oil mixture. Group 3, the positive control fed with high-fat-high-cholesterol diet containing 0.74% (w/w) phytosterols. Groups 4–6 were the high-fat-high-cholesterol diet mixed with phytosterol-containing lactic-fermented milk powder (PSFMP) which contains 0.37%, 0.74% and 1.85% (w/w) of phytosterols, respectively. Results demonstrated that PSFMP could significantly decrease (P < 0.05–P < 0.001) the levels of total cholesterol (serum cholesterol), serum triacylglycerol, liver lipids and atherogenic index (LDL-C/HDL-C), while it could also significantly (P < 0.001) increase the level of fecal cholesterol. The pronounced hypolipidemic effects of PSFMP might be attributed to its ability to enhance cholesterol excretion. These results suggest that PSFMP could be used as a potential cholesterol-lowering ingredient in the management of hypercholesterolemia.     

Comparison of lipoprotein fractionation by sequential density gradient ultracentrifugation with precipitation or fast phase liquid chromatography

Lipoprotein fractions, i.e. very low density (VLDL, ρ=0.93−1.019), low density (LDL, ρ=1.019−1.063), and high density lipoprotein (HDL, ρ=1.063−1.21) were separated by sequential gradient density ultracentrifugation (SDGU) and their cholesterol values were determined and compared with values determined by fast phase liquid chromatography (FPLC) or HDL cholesterol by phosphotungstic acid-MgCl₂ (PTMg) precipitation in hamsters fed diets containing various levels of cholesterol. The correlation coefficient (r) for LDL between the SDGU and FPLC methods in plasma from hamsters fed 0–3% cholesterol diets was 0.21–0.51, n=45. The FPLC method over estimated (+45%) LDL and the HDL values were under estimated (−18%). The agreement between FPLC and SDGU methods was also evaluated by plotting mean values against the differences between the values obtained by the two methods. FPLC method overestimated LDL 22–49% (mean 36%) and HDL was underestimated 14–27% (mean 20%). This was significant systematic bias with the FPLC method in VLDL, LDL and HDL values with the level of cholesterol in the diet. As FPLC is a fast method, it could be used in intervention type experiments to monitor the progress, however final results may need validation for research studies with the SDGU method. HDL determined by the SDGU method and phosphotungstic acid MgCl₂ precipitation in hamsters (n=26) fed 0.25% cholesterol diets was represented by two significantly different (P⩽0.05) divergent lines when a regression fitted model and a one-to-one relationship model by the two methods were plotted. The data suggest that in hamsters fed either no added cholesterol or cholesterol-containing diets, lipoprotein fractions determined by the precipitation method or by FPLC need to be validated against a SDGU for critical samples.     

Hypocholesterolemic and Anti‐Obesity Effects of Saponins from Platycodon grandiflorum in Hamsters Fed Atherogenic Diets

ABSTRACT: Platycodins, a group of saponin glycosides from Platycodon grandiflorum, are believed to possess anti‐obesity and cholesterol‐lowering properties. The aim of the present study was to investigate whether dietary platycodins affect plasma, hepatic, or fecal cholesterol concentrations, as well as cholesterol absorption and fractional synthesis rates in a dose‐dependent manner. Golden Syrian hamsters (n= 45) were fed atherogenic (0.25% cholesterol) diets enriched with platycodins in the forms of either aqueous extracts (containing 0.3% to 0.5% of platycodins of diet mass) or crude saponins fractions (containing 0.9% to 1.0% of platycodins of diet mass) for 28 d. {3, 4}⁻¹³C‐cholesterol and ²H₂O tracers were administered on days 26 and 28 to assess cholesterol absorption and biosynthesis, respectively. After platycodin intervention, total cholesterol concentrations in plasma and liver were reduced (P < 0.05) by 13% to 28% and 41% to 79%, respectively, whereas cholesterol concentrations in feces were increased (P < 0.05) up to 2.5‐fold compared to controls. Platycodin feeding increased (P < 0.001) cholesterol absorption up to 60%, but not cholesterol synthesis. These results suggest that platycodin‐enriched diets can lower circulating and whole body cholesterol contents, and thus reduce the risk of cardiovascular diseases through mechanisms independent from cholesterol absorption or synthesis.