昆布（海带）对高脂血症大鼠血脂的调节作用和机制

目的：探讨昆布（海带）在实验性高脂血症大鼠中的降血脂作用和机制。方法：健康雌性Wistar大鼠40只,应用高脂饲料喂养方法建立高脂血症动物模型,海带粉饲料喂养干预治疗。生化法检测大鼠血清甘油三酯（TG）、总胆固醇（TC）、低密度脂蛋白（LDL）和高密度脂蛋白（HDL）水平。硫代巴比妥酸法和硝酸还原酶法分别检测脂质过氧化物丙二醛（MDA）和一氧化氮（NO）含量,黄嘌呤氧化酶法和化学比色法分别测定超氧化物歧化酶（SOD）和谷胱甘肽过氧化物酶（GSH-PX）活性。结果：经海带干预治疗后,动物血清TG、TC和LDL水平较模型组显著降低、HDL水平显著升高（P〈0.05）。治疗组动物血清和肝组织MDA和NO水平显著低于、而SOD和GSH-PX活性均显著高于模型组（P〈0.05）。结论：海带可能影响TG、TC、LDL和HDL等组分的代谢,通过增强抗氧化SOD和GSH-PX的活性,降低体内MDA和NO的水平,发挥调节血脂水平的作用。     

昆布（海带）对高脂血症大鼠血脂的调节作用和机制

目的:探讨昆布(海带)在实验性高脂血症大鼠中的降血脂作用和机制。方法:健康雌性Wistar大鼠40只,应用高脂饲料喂养方法建立高脂血症动物模型,海带粉饲料喂养干预治疗。生化法检测大鼠血清甘油三酯(TG)、总胆固醇(TC)、低密度脂蛋白(LDL)和高密度脂蛋白(HDL)水平。硫代巴比妥酸法和硝酸还原酶法分别检测脂质过氧化物丙二醛(MDA)和一氧化氮(NO)含量,黄嘌呤氧化酶法和化学比色法分别测定超氧化物歧化酶(SOD)和谷胱甘肽过氧化物酶(GSH-PX)活性。结果:经海带干预治疗后,动物血清TG、TC和LDL水平较模型组显著降低、HDL水平显著升高(P<0.05)。治疗组动物血清和肝组织MDA和NO水平显著低于、而SOD和GSH-PX活性均显著高于模型组(P<0.05)。结论:海带可能影响TG、TC、LDL和HDL等组分的代谢,通过增强抗氧化SOD和GSH-PX的活性,降低体内MDA和NO的水平,发挥调节血脂水平的作用。     

Effect of Gymnema montanum Leaves on Serum and Tissue Lipids in Alloxan Diabetic Rats

The effect of Gymnema montanum leaves on alloxaninduced hyperlipidemia was studied in male Wistar rats. Ethanolic extract of G. montanum leaves was administered orally and different doses of the extract on blood glucose, serum and tissue lipids, hexokinase, glucose-6-phosphatase, thiobarbituric acid–reactive substances (TBARS), hydroperoxides, and glutathione in alloxan-induced diabetic rats were studied. G. montanum leaf extract (GLEt) at doses of 50, 100, 200 mg/kg body weight for 3 weeks suppressed the elevated blood glucose and lipid levels in diabetic rats. GLEt at 200 mg/kg body weight was found to be comparable to glibenclamide, a reference drug. These data indicate that G. montanum represents an effective antihyperglycemic and antihyperlipidemic adjunct for the treatment of diabetes and a potential source of discovery of new orally active agent for future therapy.     

Effect of Fermented Bean Paste on Serum Lipids in Rats Fed a Cholesterol-Free Diet

We examined the effects of fermented bean pastes derived from bean vinegar by-products on serum cholesterol in rats. The rats were fed boiled paste from adzuki (A), kintoki (K), or tebou (T), or fermented paste from adzuki (AP), kintoki (KP), or tebou (TP) for 4 weeks. The serum non-high-density lipoprotein (HDL) cholesterol levels in all the experimental groups, except for A group, were significantly lower than in the control (CN) group. Likewise, the serum triglyceride levels in K and all the fermented bean groups were significantly lower than in the CN group. The levels of hepatic 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) reductase mRNA in all the experimental groups except for A were significantly lower than in the CN group. These findings indicate that fermented bean pastes also suppress cholesterol synthesis, resulting in a reduced serum cholesterol concentration. These effects might be related not only to the resistant starch but also to the protein or peptide in the fermented bean paste.     

喂饲Lactobacillus casei Zhang对大鼠体内脂质代谢的影响

从内蒙古锡林郭勒盟正蓝旗传统酸马奶中分离筛选到1株降胆固醇功效较好的乳杆菌Lactobacillus．casei Zhang。用Lb．casei Zhang灌胃高脂血症模型大鼠研究其对血清总胆固醇(TC)、甘油三酯(TG)、高密度脂蛋白胆固醇(HDL-C)、低密度脂蛋白胆固醇(LDL-C)的影响。结果表明:灌胃14 d后,Lb．casei Zhang热致死菌体组大鼠血清中TC浓度较对照组显著降低(P<0．01),TG浓度虽有降低但不呈显著性,同时HDL-C浓度显著升高(P<0．05);Lb．casei Zhang活菌体组大鼠血清中TC、TG浓度均有所降低,HDL-C浓度升高,但未呈显著性。灌胃28 d后,Lb．casei Zhang热致死菌体组大鼠血清中TC浓度较对照组显著降低(P<0．05),Lb．casei Zhang活菌体组TC浓度及两组TG、LDL-C浓度降低,但差异不显著,HDL-C未发生明显的改变。Lb．casei Zhang热致死菌体组和活菌体组粪便中的胆酸含量均增高,但只有热致死菌体组差异显著(P<0．05)。通过实验表明Lb．casei Zhang通过菌体对胆固醇的吸收吸附及减少肝肠循环中的胆酸来达到降血脂的功效。     

Effect of Dietary Composition on Lipids in Serum and in Liver of Rats Fed a Cystine-excess Diet

The effects of dietary composition on lipids in serum and in liver of rats fed with a cystine- excess diet were investigated.

When starch was used as the carbohydrate source, the addition of excess-cystine caused an increase in serum cholesterol and phospholipids, and hepatomegaly. Phospholipids in serum of rats fed with a cystine-excess diet containing 5% corn oil were higher than those with a cystine-excess diet that was low in corn oil (0.1 %). The addition of konjac mannan and pectin prevented hypercholesterolemia, and the rise in phospholipids in serum was prevented by the addition of konjac mannan.

Liver cholesterol (mg/liver/100 g of body wt.) increased in rats fed with a cystine-excess diet.

The addition of excess cystine to a diet containing sucrose as the carbohydrate source resulted in a marked increase of cholesterol in serum and liver, and a decrease of serum triglycerides.

The replacement of starch by sucrose in the cystine-excess diet increased liver cholesterol.

Lipids, cholesterol, phospholipids and triglycerides in the liver, but not phospholipids, when expressed as mg per g of liver for rats fed with the diets containing sucrose, increased when compared to those for rats fed with the diets containing starch. In contrast, serum triglycerides increased.     

Resveratrol Has No Effect on Lipoprotein Profile and Does Not Prevent Peroxidation of Serum Lipids in Normal Rats

Trans-resveratrol, one of the antioxidants found in red wine, has been the subject of controversial reports regarding its protective role against cardiovascular diseases. In this study we synthesized trans-resveratrol and injected it to rats (20 and 40 mg/kg body weight, once a day for 21 days, i.p.) to determine its effect on the serum lipid profile. Synthetic trans-resveratrol was an effective antioxidant in vitro against hydroxyl radical (I₅₀ = 33 μM). Resveratrol treatment, however, did not have any effect on either the lipid profile or on Cu⁺²-dependent formation of thiobarbi-turic-acid-reactive substances (TBARS) from protein-associated lipids. Since the amount of resveratrol used in these experiments was orders of magnitude higher than the amounts found in wine, these results suggest that if resveratrol has any effect against coronary heart diseases, it is not related to its antioxidant role on lipids or to changes in lipoprotein profile.     

Resveratrol Has No Effect on Lipoprotein Profile and Does Not Prevent Peroxidation of Serum Lipids in Normal Rats

Trans-resveratrol, one of the antioxidants found in red wine, has been the subject of controversial reports regarding its protective role against cardiovascular diseases. In this study we synthesized trans-resveratrol and injected it to rats (20 and 40 mg/kg body weight, once a day for 21 days, i.p.) to determine its effect on the serum lipid profile. Synthetic trans-resveratrol was an effective antioxidant in vitro against hydroxyl radical (I₅₀ = 33 μM). Resveratrol treatment, however, did not have any effect on either the lipid profile or on Cu⁺²-dependent formation of thiobarbi-turic-acid-reactive substances (TBARS) from protein-associated lipids. Since the amount of resveratrol used in these experiments was orders of magnitude higher than the amounts found in wine, these results suggest that if resveratrol has any effect against coronary heart diseases, it is not related to its antioxidant role on lipids or to changes in lipoprotein profile.     

高脂血症恒河猴血清RETN与血脂的相关性分析

目的探讨高脂血症恒河猴血清抵抗素（RETN）水平与血脂的相关性。方法高脂血症恒河猴和健康恒河猴各8只,分别为实验组及对照组,测定其空腹血清RETN、总胆固醇（TC）、甘油三酯（TG）、高密度脂蛋白（HDL-C）、低密度脂蛋白（LDL-C）,分析高脂血症恒河猴血清RETN水平与血脂的关系。结果实验组的血清RETN水平、TC、LDL-C显著高于对照组（P〈0.05）,实验组TG较对照组显著降低（P〈0.05）;两组HDL-C差异不显著（P〉0.05）。相关分析显示,血清RETN与TC、LDL-C正相关,与TG负相关,与HDL-C无相关性。结论高脂血症恒河猴血清RETN水平与血脂存在相关性,可为人类高脂血症研究提供实验数据。     

Studies on the Essential Oils of Tobacco Leaves

An investigation was conducted on the neutral fraction in the essential oil of Virginia tobacco leaves. α-Pyrryl methyl ketone, ethyl alcohol, ethyl acetate and furfuryl alcohol were isolated and identified. An alcohol, C₄, and an ester of benzoic acid were also separated. Hydrocarbons were separated from the total neutral fraction by liquid chromatography, prior to any further procedure; and a straight chain paraffin near C₃₀ and an unsaturated hydrocarbon resembling myrcene were also isolated and their contents were determined. A technique of chromatostrip was found to be very useful for detecting liquid chromatographic separation.     

Studies on the Essential Oils of Tobacco Leaves

The basic fraction contained in the essential oil of the Japanese Flue Cured Tobacco Leaf (before redrying) was investigated and 2,3′-dipyridyl was isolated and identified. While, on the other hand, the basic fraction of the essential oil of the aged Japanese Burley Tobacco Leaf was also investigated and nicotine was found to be the predominant constituent of that fraction. At the same time, a small amount of 2,3′-dipyridyl and myosmine was also isolated and identified.     

Effect of White Wheat Bread Containing Sugar Beet Fiber on Serum Lipids and Hepatic mRNA in Rats Fed on a Cholesterol-Free Diet

We examined the effects of white wheat bread powder (BP) and white wheat bread powder containing sugar beet fiber (BBP) on serum cholesterol. The total cholesterol (?11%, ?16%), HDL-cholesterol (?12%, ?11%), non-HDL-cholesterol (?9%, ?18%) and triacylglycerol (?44%, ?58%) concentrations in the BP and BBP groups, respectively, were significantly different from those in the control group. The fecal excretion of neutral sterols in the BP and BBP groups and of acidic sterols in the BBP group was significantly higher than that in the control group. The hepatic cholesterol 7α-hydroxylase (CYP7A1) mRNA level in the BP and BBP groups was significantly higher than that in the control group. The cecal total short-chain fatty acid concentrations in the BBP group were significantly higher than those in the control group. These results indicate that the observed changes in serum lipid levels in the BP and BBP groups were due to the increased fecal lipid and CYP7A1 mRNA levels.     

Effect of Acipimox on Plasma Lipids and Glucose/Insulin in Pregnant Rats

To determine how a reduction in maternal hypertriglyceridemia during late pregnancy may affect glucose/insulin relationships, pregnant and virgin rats were orally treated with acipimox, a potent antilipolytic agent. In 20-day pregnant rats receiving 80 mg of acipimox, plasma triglycerides (TG), free fatty acids (FFA), and glycerol decreased more than in virgin rats shortly after the drug (up to 7 hours), when compared with animals treated with distilled water, whereas plasma glucose level was unaffected by the treatment in either group of rats. When acipimox was given every 12 hours from day 17 to day 20 of pregnancy, plasma TG, FFA, and glycerol levels progressively increased, whereas they either decreased or did not change in virgin rats receiving the same treatment, with no effect in plasma glucose levels in either group. Fetal body weight was lower than in controls in 20-day pregnant rats that received acipimox for 3 days. On day 20 of pregnancy, 3 hours after receiving acipimox or distilled water, rats received a 2 g glucose/kg oral load and it was found that the change in plasma glucose was similar in both groups, whereas the increase in plasma insulin was greater in pregnant rats treated with acipimox. However, no difference was found in either variable after the oral glucose load in virgin rats receiving acipimox or distilled water. No differences in plasma glucose levels were found after intravenous (IV) administration of insulin in pregnant rats treated or not treated with acipimox. In conclusion, present results show that administration of acipimox during the last days of gestation inhibited lipolysis and decreased fetal weight. Over a short period of time, in pregnant rats, reductions of plasma FFA and TG after acipimox treatment improved the glucose-induced insulin release, but did not seem to have any effect in peripheral insulin resistance.     

Effect of Endotoxin on the Serum Ribonuclease Activity in Rats

The effects of endotoxin shock, endotoxin tolerance, and lead acetate plus a minute amount of endotoxin on the serum ribonuclease activity of rats was measured. Changes in serum ribonuclease activity after various entoxin treatments could be a primary effect or a secondary effect of the damaging effect of endotoxin.     

Studies on the Essential Oils of the Genus Mentha

The essential oil of Mentha japonica Makino (Japanese name, Himehakka) was found to consist mainly from l-menthone (50.8%), d-isomenthone (18.6%) and d-pulegone (12.6%) besides smaller amounts of α-pinene (0.4%), β-pinene (0.3%), limonene (0.3%), 3-octanone (3.6%), 1,8-cineole (0.8%), p-cymene (0.1%) 3-octyl acetate (0.8%), 3-octanol and a ketone (1.9%), 3-methylcyclohexanone (0.1%), 1-octen-3-ol (0.9%), menthyl acetate (1.8%), l-isopulegone (0.6%), menthol (0.4%), piperitone (2.6%), trans-pulegone oxide (0.4%), isopiperitenone (0.4%), cis-pulegone oxide (0.4%), piperitenone (0.2%) and other compounds.

Some considerations to the relationships among M. Pulegium, M. Gattefossei and M. japonica have been done from viewpoint of the chemical systematics.     

Effect of Intramuscular Administration of Retinol on Plasma Lipids of Rats

The effect of intramuscular administration of 100,000 I. U. of retinol daily for 13 days on plasma lipids of young rats has been studied. Significant elevations in the plasma total lipids, phospholipids and glycerides were noted in retinol treated rats as compared to control rats. Although significant elevations were noted in plasma phospholipids, the percentage distribution of plasma phospholipid components was unaffected in retinol treated rats as compared to control group.     

Inhibitory Effect of Essential Oils on Aspergillus ochraceus Growth and Ochratoxin A Production

Ochratoxin A (OTA) is a mycotoxin which is a common contaminant in grains during storage. Aspergillus ochraceus is the most common producer of OTA. Essential oils play a crucial role as a biocontrol in the reduction of fungal contamination. Essential oils namely natural cinnamaldehyde, cinnamon oil, synthetic cinnamaldehyde, Litsea citrate oil, citral, eugenol, peppermint, eucalyptus, anise and camphor oils, were tested for their efficacy against A. ochraceus growth and OTA production by fumigation and contact assays. Natural cinnamaldehyde proved to be the most effective against A. ochraceus when compared to other oils. Complete fungal growth inhibition was obtained at 150–250 µL/L with fumigation and 250–500 µL/L with contact assays for cinnamon oil, natural and synthetic cinnamaldehyde, L. citrate oil and citral. Essential oils had an impact on the ergosterol biosynthesis and OTA production. Complete inhibition of ergosterol biosynthesis was observed at ≥100 µg/mL of natural cinnamaldehyde and at 200 µg/mL of citral, but total inhibition was not observed at 200 µg/mL of eugenol. But, citral and eugenol could inhibit the OTA production at ≥75 µg/mL and ≥150 µg/mL respectively, while natural cinnamaldehyde couldn’t fully inhibit OTA production at ≤200 µg/mL. The inhibition of OTA by natural cinnamaldehyde is mainly due to the reduction in fungal biomass. However, citral and eugenol could significant inhibit the OTA biosynthetic pathway. Also, we observed that cinnamaldehyde was converted to cinnamic alcohol by A. ochraceus, suggesting that the antimicrobial activity of cinnamaldehyde was mainly attributed to its carbonyl aldehyde group. The study concludes that natural cinnamaldehyde, citral and eugenol could be potential biocontrol agents against OTA contamination in storage grains.