Effects of administration of α-tocopherol and tocotrienols on serum lipids and liver HMG CoA reductase activity

Male hamsters were fed on semi-synthetic diets containing commercial corn oil (CO), isolated corn oil triglycerides (COTG), COTG supplemented with 30 ppm of α -tocopherol (COTGT L) and COTG supplemented with 81 ppm of α -tocopherol (COTGT H) as the dietary lipid for 45 days. Male albino guinea pigs were fed on commercial chow pellets and treated with different dosages of tocopherol and tocotrienols intra-peritoneally for 6 consecutive days. Serum and liver were taken for analysis. Our results show that stripping corn oil of its unsaponifiable components resulted in COTG which yielded lower serum total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) and raised high-density lipoprotein cholesterol (HDL-C) and serum triglycerides (TG) levels. These results indicate that the COTG with its fatty acids are responsible for the hypocholesterolemic effect exhibited by corn oil. However, supplementing the COTG diet with α -tocopherol (α -T) at 30 ppm significantly raised the serum TC, LDL-C and TG levels, but did not alter the HDL-C level, indicating that α -T is hypercholesterolemic. Supplementing the COTG diet with α -T at 81 ppm raised the serum TC level but to a lesser extent as compared to that obtained with 30-ppm α -T supplementation. The increased TC, in this case, was reflected mainly by an increased in HDL-C level as the LDL-C level was unchanged. The TG level was also raised but to a lesser extent than that obtained with a lower α -T supplementation. The liver HMG CoA reductase (HMGCR) activity was exhibited (56%) by the COTG as compared to CO. Supplementation of α -T at 30 ppm to the COTG diet resulted in further inhibition (76%) of the liver HMGCR activity. On the contrary, supplementation of α -T at 81 ppm to COTG diet resulted in a highly stimulatory effect (131%) on the liver HMGCR activity. Short-term studies with guinea pigs treated intra-peritoneally with α -T showed that at low dosage (5 mg) the HMGCR activity was inhibited by 46% whereas increasing the dosage of α -T to 20 mg yielded lesser inhibition (18%) as compared to that of the control. Further increase in the dosage of α -T to 50 mg actually resulted in 90% stimulation of the liver HMGCR activity as compared to the control. These results clearly indicate that the effect of α -T on HMGCR activity was dose-dependent. Treatment of the guinea pigs with 10 mg of tocotrienols (T3) resulted in 48% inhibition of the liver HMGCR activity. However, treatment with a mixture of 5 mg of α -T with 10 mg of T3 resulted in lesser inhibition (13%) of the liver HMGCR activity as compared to that obtained with 10 mg of T3. The above results indicate that the α -T is hypercholesterolemic in the hamster and its effect on liver HMGCR is dose-dependent. T3 exhibited inhibitory effect on liver HMGCR and α -T attenuated the inhibitory effect of T3 on liver HMGCR.     

Effect of dietary fat content and composition during pregnancy on fetal hepatic HMG CoA reductase activities and lipids in rats

The effects of diets containing 20% (wt/wt) safflower, olive or palm oil or 5% (wt/wt) safflower oil when fed throughout gestation on hepatic 3-hydroxy-3-methylglutaryl coenzyme A (HMG CoA) reductase activity and on plasma and liver lipids were studied in fetal rats at d 21 of gestation. Hepatic total and active HMG CoA reductase activity, plasma free cholesterol and liver triglyceride and phospholipid 18:2(n-6) levels were higher in fetuses of rats fed 20% than in those of rats fed 5% safflower oil. Fetuses of rats fed olive oil had higher active HMG CoA reductase levels than fetuses of rats fed 20% safflower or palm oil; their total reductase activity was similar to that of the safflower oil group and higher than that for the palm oil group. Fetal liver and plasma cholesterol and triglyceride, as well as liver phospholipid concentrations, were not altered by the type of oil fed. The diets containing safflower oil resulted in higher 18:2(n-6) and lower 18:1 levels in fetal liver phospholipid and triglycerides than did the diets containing palm or olive oil. These studies demonstrate that fetal liver HMG CoA reductase activity is influenced by the maternal diet fat content and composition although the effect of specific fatty acids is unknown.     

Effect of bran and citrus pulp on hepatic, small intestinal and colonic HMG CoA reductase, cytochrome P450 and cytochrome b5 levels in rats

The effect of dietary wheat bran and citrus pulp on hepatic, small intestinal and colonic HMG-CoA reductase activity, cytochrome P450 and cytochrome b5 levels was studied in F344 rats. Colonic and small intestinal HMG-CoA reductase activity was significantly lower in the wheat bran group than the control group. No differences in hepatic HMG-CoA reductase activity occurred between the wheat bran, citrus pulp and control groups. A direct relationship between hepatic cholesterol levels and hepatic Cytochrome P450 levels was demonstrated. A similar trend was exhibited between fecal cholesterol and colonic cytochrome P450 levels in the colon. These results suggest that the effect of certain types of dietary fiber in small intestinal and colonic cholesterogenesis is mediated through alterations in small intestinal and colonic mixed function oxidase activity.     

蛋白酶体抑制剂对人晶状体上皮细胞的增殖抑制作用

目的 探讨蛋白酶体抑制剂MG132对SRA01/04细胞增殖的影响.方法 以不同浓度MG132处理SRA01/04细胞36 h,通过MTT微量比色法检测MG132对SRA01/04细胞活力的影响,通过流式细胞术（FCM）检测MG132对SRA01/04细胞凋亡及细胞周期的影响,通过AnnexinV/FITC-PI双染法观察MG132对SRA01/04细胞的影响.结果 随着浓度的提高（0、0.1、0.5、1.0、2.5、5.0、10.0 μmol/L）,MG132对SRA01/04细胞增殖的抑制作用逐渐增强.36 h时,半数有效抑制浓度IC50为2.50μmol/L.FCM检测细胞凋亡结果：2.5、5.0 μmol/L的MG132作用于SRA01/04细胞36 h,细胞早期凋亡率分别为（6.55±0.35）%和（13.75±3.18）%,而对照组为（0.75±0.21）%,差异有统计学意义（P＜0.01）.2.5、5.0 μmol/L MG132处理SAR01/04细胞48 h,G0/G1期细胞比例分别为（73.42±3.10）%,（80.95%±3.83）%,而对照组为（42.57±0.64）%,差异有统计学意义（P＜0.01）;S期细胞比例分别为（17.40±1.50）%,（19.57±1.29）%,而对照组为（49.44±1.36）%,差异有统计学意义（P＜0.01）.免疫荧光镜下,MG132诱导SRA01/04细胞的早期凋亡.结论 蛋白酶体抑制剂MG132诱导细胞凋亡、影响细胞周期来抑制SRA01/04细胞的增殖.蛋白酶体抑制剂可起到防治后发性白内障的作用.     

Short-term effect of the HMG-CoA reductase inhibitor rosuvastatin on erythrocyte nitric oxide synthase activity

Prevention and treatment of cardiovascular disorders by HMG-CoA reductase inhibitors (or statins), beyond their lipid-lowering properties, have been demonstrated including activation of the endothelial nitric oxide synthase (eNOS). Beside endothelial cells, red blood cells (RBCs) possess NOS and produce nitric oxide (NO), which contributes to RBC deformability. The present study tested the capacity of statins to activate NOS in RBCs and subsequently to modulate RBC deformability in vitro. Blood samples of healthy young volunteers were incubated with or without rosuvastatin. Afterwards RBC-NOS activity and RBC deformability were determined. Rosuvastatin incubation significantly increased NOS phosphorylation, NOS dependent NO-formation, and RBC deformability. The NOS inhibitor NG- monomethyl-L-arginine reversed the stimulatory effect of rosuvastatin on RBC-NOS activity. This NO dependent effect of rosuvastatin might have an important influence on microcirculation and may offer new perspectives for the therapeutic use of statins.     

Inhibitory effect of Cladosiphon fucoidan on the adhesion of Helicobacter pylori to human gastric cells.

We studied the inhibitory effect of Cladosiphon fucoidan on the attachment of Helicobacter pylori (H. pylori), a gastroduodenal pathogen, to human gastric cell lines. The bacterial binding in these cell lines was inhibited more by Cladosiphon fucoidan (IC50 = 16-30 mg/mL), than by the fucoidan from Fucus (IC50 > 30 mg/mL). Dextran sulfate, another sulfated polysaccharide, did not inhibit the binding at all. Pre-incubating the bacterial suspension with fucoidans reinforced the inhibitory ability of these components, and reduced the IC50 value of Cladosiphon fucoidan to approximately 1 mg/mL. However, the binding was not inhibited by pre-treatment of gastric cells with these components. It was also shown that this fucoidan blocks both Leb- and sulfatide-mediated attachment of H. pylori to gastric cells. Furthermore, fucoidan-binding proteins were found on the H. pylori cell surface by Western blot analysis. Thus, the inhibitory effect exerted by Cladosiphon fucoidan on binding between H. pylori and gastric cells might result from the coating with this component of the bacterial surface.     

Inhibitory effect of Erythronium japonicum on the human breast cancer cell metastasis

BACKGROUND/OBJECTIVESIn this study, the inhibitory effect of Erythronium japonicum extracts on the metastasis of MDA-MB-231 human breast cancer cell line was determined.MATERIALS/METHODSCells were cultured with DMSO or with 50, 75, 100 or 250 µg/ml of Erythronium japonicum methanol or ethanol extract.RESULTSBoth methanol and ethanol extracts significantly inhibited the growth and induced apoptosis of MDA-MB-231 cells in a dose-dependent manner. Erythronium japonicum extracts inhibited the adhesion of MDA-MB-231 cells. The invasion of breast cancer cells was suppressed by Erythronium japonicum extracts in a dose-dependent manner. The motility and MMP-2 and MMP-9 activities were also inhibited by both methanol and ethanol extracts.CONCLUSIONSOur results collectively indicate that Erythronium japonicum extracts inhibit the growth, adhesion, migration and invasion as well as induce the apoptosis of human breast cancer cells. Clinical application of Erythronium japonicum as a potent chemopreventive agent may be helpful in limiting breast cancer invasion and metastasis.     

槲皮素抑制体外培养的人眼晶状体上皮细胞生长的研究

目的研究槲皮素对体外培养的人眼上皮细胞的抑制作用。方法时先天性白内障患者术中环行撕前囊膜，进行原代培养并传代，取第二代细胞用于实验，MTT法观察不同浓度的槲皮素（10μmol／ml、20μmol／ml、40μmol／ml、80μmol／ml、160μmol／m1）对晶状体上皮细胞的粘附的抑制作用；对基本融合的细胞进行划线，160μmol／ml的槲皮素进行干预，细胞计数法观察裸露区内细胞的移行数量；MTT法测定槲皮素对晶状体上皮细胞增殖的抑制效应。结果不同浓度的槲皮素（40μmol／ml、80μmol／ml、160μmol／m1）对晶状体上皮细胞的粘附和增殖具有抑制作用。160μmol／ml槲皮素明显抑制其移行。结论槲皮素对体外培养的人眼晶状体上皮细胞具有抑制作用，安全有效。     

UbcH10基因沉默对裸鼠移植性大肠癌抑制作用

目的 通过短发夹RNA(shRNA)干扰沉默UbcH10基因的表达,并观察其对裸鼠移植结直肠癌的抑制作用。方法 构建RNA干扰表达载体pGPU6/GFP/Neo/UbcH10-RNAi(pUbcH10-RNAi),建立UbcH10基因沉默细胞系HT-29/UbcH10-RNAi;采用蛋白印迹法(western blot)评价pUbcH10-RNAi对UbcH10基因表达的影响,观察移植结直肠癌裸鼠的肿瘤生长情况。结果 HT-29/UbcH10-RNAi细胞中UbcH10基因表达明显下调;与对照组比较HT-29/UbcH10-RNAi组肿瘤生长明显减慢,在接种肿瘤细胞12 d后隐约可见瘤体,36 d后断颈处死剥离瘤体重量仅是对照组肿瘤的40%左右。结论 短发夹RNA(shRNA)沉默UbcH10基因对裸鼠移植性大肠癌有抑制作用,提示抑制UbcH10基因表达可能是大肠癌治疗的潜在方法。     

共轭亚油酸对人胃腺癌细胞的抑制作用

采用体外细胞培养方法，研究共轭亚油酸（ＣＬＡ）对人胃腺癌细胞（ＳＧＣ－７９０１）生长的影响。ＣＬＡ的剂量分别为２５、５０、１００和２００μｍ ｏｌ／Ｌ，以乙醇为溶剂对照。结果表明：ＣＬＡ 能抑制ＳＧＣ－７９０１细胞的增殖、细胞核分裂、集落形成和细胞ＤＮＡ的合成，并诱导ＳＧＣ－７９０１细胞的分化     

葡多酚对辐射引发胰腺细胞凋亡的抑制作用

目的　探讨葡多酚 (GPC)对辐射引发的细胞凋亡与增殖活性损伤的防护作用。方法　给口服不同剂量GPC的小鼠用 60 Co γ射线进行 1次全身性照射 ,照射后第 2天处死动物 ,取胰腺组织分别检测bcl 2和bax表达水平、细胞增殖活性及凋亡率等指标。结果　高剂量GPC组动物的细胞增殖率为 3.16 %± 0 .13% ,bcl 2表达水平为 4 9.8% ,均较辐射对照组 (分别为 0 .6 4 %± 0 .11%、2 9 .7% )高 ;而细胞凋亡率和bax表达水平则为 19.8%和 5 5 .0 % ,均低于辐射对照组 (35 .6 %、85 .7% )。各组间差异均有显著性 (P <0 .0 5 )。结论　GPC可抑制60 Co γ射线诱发的小鼠胰腺细胞凋亡及相关基因的异常表达 ,对辐射损伤有一定防护作用。     

Positive pleiotropic effects of HMG-CoA reductase inhibitor on vitiligo

Background  

HMG-CoA reductase inhibitors (statins) are commonly used in medicine to control blood lipid disorder. Large clinical trials have demonstrated that statins greatly reduces cardiovascular-related morbidity and mortality in patients with and without coronary artery disease. Also, the use of HMG-CoA reductase inhibitors has been reported to have immunosuppressive effects.     

c-FLIP反义寡核苷酸对肺癌A549细胞裸鼠移植瘤抑制作用

目的 研究细胞型Fas相关死亡域样白介素-1β转换酶抑制蛋白反义寡核苷酸(c-FLIP-ASODN)对肺癌A549细胞裸鼠移植瘤的抑制作用.方法 采用肺癌A549细胞株建立裸鼠移植瘤模型,将其分为ASODN组及空白对照组、脂质体转染组、无义寡核苷酸(SODN)组,通过移植瘤生长曲线、终末瘤重免疫组化法检测c-FLIP蛋白表达、增殖指数,逆转录-聚合酶链反应(RT-PCR)检测移植瘤c-FLIP mRNA变化,TUNEL检测凋亡指数.结果 ASODN干预后移植瘤生长缓慢,22 d时瘤体积达到最大,此后呈缩小趋势,终末瘤体积及瘤重分别为(376.9±45.8)mm3、(512.4±33.6)mg,明显低于其他各组(P＜0.01),抑瘤率为64.31%;ASODN组移植瘤组织增殖指数为(25.71±5.42),c-FLIP mRNA表达量为(0.30±O.05),c-FL.IP蛋白表达阳性率为(19.54±6.36),均明显低于各对照组;凋亡指数为(39.68±6.28),明显高于其他各组(P＜0.01).结论 c-FLIP-ASODN对肺癌A549细胞裸鼠移植瘤生长有抑制作用,其机制与降低c-FLIP mRNA和蛋白表达、抑制移植瘤细胞的增殖活性和促进肿瘤细胞凋亡有关.     

藤梨根提取物对食管癌EC109细胞抑制作用

目的 观察藤梨根乙酸乙酯提取物对食管癌EC109细胞生长、凋亡影响,并探讨其作用机制.方法 体外培养食管癌EC109细胞,分别给予不同浓度的藤梨根乙酸乙酯提取物进行干预,四甲基偶氮噻唑蓝(MTT)法检测细胞增殖抑制率,流式细胞术检测用药后EC109细胞凋亡率变化,免疫组化法检测用药后EC109细胞B细胞淋巴瘤/白血病-2基因(Bcl -2)、Bcl -2相关X蛋白(Bax)蛋白表达变化,激光共聚焦显微技术测定用药后EC109细胞胞内[Ca2+]i变化.结果 细胞培养24、48、72 h后,对照组细胞凋亡率分别为(1.67±0.76)％、(2.32±0.45)％、(2.98±0.89)％,Bcl -2蛋白表达率分别为(50.12±3.41)％、(49.78±5.65)％、(51.25±6.34)％,Bax蛋白表达率分别为(17.98±2.85)％、(18.27±3.12)％、(17.76±3.64)％,而各干预组细胞凋亡率为7.05％ ～51.11％,均明显增加(t=5.419～17.826,P＜0.05),存在时-效和量-效趋势,同时其细胞Bcl -2蛋白表达降低,为43.32％ ～ 10.46％,Bax蛋白表达上调,为24.54％～ 63.47％,均存在时-效和量-效趋势,当作用时间≥48 h或浓度≥100 μg/mL时,干预组上述变化与对照组比较,差异有统计学意义(Bcl-2∶t=3.58～10.14;Bax∶t =5.047 ～ 11.065,P＜0.05);用药后细胞内[Ca2+]i明显升高,12h达高峰,此后缓慢减低,至48 h仍明显高于对照组.结论 藤梨根乙酸乙酯提取物可以明显抑制食管癌EC109细胞增殖,并诱导细胞发生凋亡,可能与降低其Bcl -2蛋白表达,上调Bax蛋白表达,升高细胞内[Ca2+]i有关.     

Inhibitory effect of succinic acid on epithelial cell proliferation of colonic mucosa in rats

Microbial breakdown of carbohydrates in the large intestine mainly produces short-chain fatty acids (SCFA). SCFA stimulate epithelial cell proliferation of the digestive tract in vivo. Succinic acid sometimes accumulates in the colonic lumen. However, the effect of succinic acid on colonic epithelial cell proliferation is unknown. Thus, we planned to clarify the influence of succinic acid on colonic epithelial cell proliferation in vivo. We continuously administered infusate with or without succinic acid (100 mM) into the distal colon of rats for 6 d and measured accumulated mitosis per crypt of distal colon of these rats. Succinic acid infused into rat colons significantly inhibited colonic cell proliferation and reduced crypt size. These results clearly indicated the inhibitory effects of succinic acid on colonic epithelial cell proliferation in vivo.     

Pantethine and pantothenate effect on the CoA content of rat liver

The role of pantethine as a precursor of CoA in rat liver has been examined. It has been demonstrated that pantethine induces a significant increase in the total CoA content both in perfused liver and in liver homogenate, while it fails to affect the mitochondrial CoA content when added to isolated mitochondria. Pantethine is more efficient than pantothenate in inducing the synthesis of CoA in rat liver, even in the presence of added cysteine. The possible metabolic implications are discussed.     

Inhibitory effect of honeybee-collected pollen on mast cell degranulation in vivo and in vitro

Bee-collected pollen (bee pollen [BP]) has been used as a folk medicine for centuries against various diseases, including allergy. There is no study elucidating how BP exerts such an anti-allergic effect. Since mast cells play a central role in the pathogenesis of various allergic diseases, we investigated the effect of BP on mast cell activation elicited by the Fc immunoglobulin E (IgE) receptor (Fc epsilon RI)-mediated pathways. The in vivo effect of orally administered BP on cutaneous mast cell activation was examined by passive cutaneous anaphylaxis reaction. In vitro mast cell degranulation and IgE binding to mast cells and the status of protein tyrosine phosphorylation were examined using bone marrow-derived mast cells. Daily oral administration of BP to mice significantly reduced the cutaneous mast cell activation elicited by IgE and specific antigens. BP also reduced in vitro mast cell degranulation and tumor necrosis factor-alpha production by inhibiting IgE binding to Fc epsilon RI on mast cells. The inhibitory effect of BP on mast cell degranulation by preventing IgE binding was confirmed by the reduced levels of protein tyrosine phosphorylation, which occurred as downstream events in activated mast cells via Fc epsilon RI. These results first revealed that the anti-allergic action of BP was exerted by inhibiting the Fc epsilon RI-mediated activation of mast cells, which plays important roles, not only in the early phase, but also in the late phase of allergic reactions.     

Lipid-lowering diets in patients taking pravastatin, a new HMG-CoA reductase inhibitor: compliance and adequacy

We examined seven 1-d diet records kept during 1 y by 272 men and women instructed to follow a lipid-lowering diet while participating in a clinical trial of pravastatin, a new 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitor. The mean percentage of calories from total fat and saturated, unsaturated, and monounsaturated fatty acids was similar throughout the year even though the patients knew they were taking an effective lipid-lowering agent. However, the diets of greater than 40% of women included less than two-thirds of the recommended dietary allowance (RDA) of folic acid, vitamins B-6 and D, and calcium and zinc; in men, folic acid and zinc intakes were low. We conclude that patients comply with lipid-lowering diets even when they know that they are receiving an effective serum lipid-lowering agent. However, for both men and women special attention should be given to the intake of several nutrients.