Effects of emodin on activity of sphingomylinase and content of ceramide in rabbit aorta of experimental atherosclerosis

AIM: To study the changes of the sphingomylinase activity and ceramide content in rabbit aorta of experimental atherosclerosis and investigate the effects of emodin on them. METHODS: The qualified rabbits were fed with food containing 1% cholesterol and 5% lard for 10 weeks to establish the animal models. The concentration of cholesterol (TC) was assayed by a enzyme method. Trace-fast-test method was used to test the activity of superoxide dismutase (SOD) and motified- BAMuGuoFu methods was employed to assay the content of myocardial malondialdehyde (MDA). Radiolabeled -enzyme-tracing was used to detect the activity of the sphingomyelinase,and thin-layered scanning was conducted to analyze the content of the ceramide in aorta. RESULTS: The ceramide content in aorta and the sphingomyelinase activity were markedly increased in the rabbits with experimental atherosclerosis. The increase was positively correlated with the content of TC and MDA and negatively correlated with the activity of SOD in blood. Compared to the model animals, emodin at concentration of 5 mg·kg^-1, 10 mg·kg^-1 and 20 mg·kg^-1 respectively reduced the area of plague on endothelium in rabbit's aortic artery and elevated the activity of SOD (P<0.05). The activity of sphingomylinase and the content of ceramide were decreased at the same time (P<0.05). 10 mg·kg^-1 emodin proved to be more effective than 5 mg·kg^-1 and 20 mg·kg^-1 emodin (P<0.01). CONCLUSIONS: Our data suggest that atherosclerosis is related to ceramide signal transduction initiated by factors such as oxidative stress in hypercholesterolemia. The emodin prevents the development of atherosclerosis probably by interfering with the above pathway.     

High-cholesterol diet with or without corn oil for establishing atherosclerotic model in rabbits

AIM：To compare the reliability and plaque area between using high-cholesterol diet and high-cholesterol diet with corn oil to establish a rabbit atherosclerotic model. METHODS：Eighteen New Zealand rabbits were randomly divided into 3 groups (6 rabbits each): normal diet group (group C), high-cholesterol diet group (group H1) and high-cholesterol diet containing 6% corn oil group (group H2). All rabbits were fed for 12 weeks, and their body mea-sured was weighed at the end of every weeks. The serum levels of high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), total cholesterol (TC) and triglyceride (TG) were measured by automatic chemistry analyzer at 0 week and 12 weeks. At the end of 12 weeks, the thoracic aorta of 8-cm length since aortic root was isolated from the rabbit after anesthesia, and stained with Sudan IV or oil red O to verify the existence of plaque. The percentage of plaque area (PA/IA) in the intima area was further calculated by ImageJ2x software. RESULTS：At the end of 12-week feeding, the serum levels of HDL-C, LDL-C and TC in both group H1 and group H2 were significantly higher than those in group C, and serum TG in group H2 was significantly higher than that in group C. Serum HDL-C in group H2 was significantly higher than that in group H1, but no significant difference of serum LDL-C, TC and TG between group H1 and group H2 was found. There was no plaque in the intima in group C, and plaques were observed in the intima of all rabbits in group H1 and group H2. Rabbit atherosclerotic models in both group H1 and group H2 were established with a success rate of 100%. The values of PA/IA in group H1 ［(49.74±18.78)%］ and group H2 ［(56.95±26.74)%］ were both significantly higher than that in group C (0%), and no significant difference of PA/IA between group H1 and group H2 was observed. CONCLUSION：High-cholesterol diet with or without corn oil can establish a rabbit atherosclerotic model with a success rate of 100% after 12-week feeding, and the percentage of plaque area in the total aortic intimal area is not different in the 2 feeding methods.     

Preventive effect of 3,4-dihydroxyacetophenone on atherosclerosis and role of visfatin expression

AIM: To observe the preventive effect of 3,4-dihydroxyacetophenone (DHAP) on atherosclerosis (AS) and the role of visfatin expression in ApoE(-/-) mice.METHODS: Eight-week-old normal mice were used in normal control group (n=8). Eight-week-old male ApoE (-/-) mice were randomly divided into 3 groups: AS group (n= 8, im. NS), DHAP treatment group (n=8, im. DHAP 10 mg·kg^-1·d^-1) and simvastatin treatment group (n=8, im. simvastatin 10 mg·kg^-1·d^-1). All mice were fed with Western diet (21% fat, 0.15% cholesterol) for 12 weeks. The blood samples were collected and the concentrations of blood lipids and visfatin were detected. The frozen sections of aortic root were stained with oil red O. The visfatin in atherosclerotic plaques at aortic roots was examined by Western blotting. The structures of smooth muscle cells and endothelial cells were observed under electron microscope. RESULTS: In DHAP-treated mice, the concentrations of visfatin, TG and TC were decreased, the formation of AS plaque was reduced, the injuries of smooth muscle cells and endothelia cells were attenuated. Visfatin was also decreased at atherosclerosis plaque in DHAP-treated mice.CONCLUSION: DHAP effectively prevents and treats AS by inhibiting the production of visfatin and reducing lipid.     

Effect of polygonum cuspidatum and hawthorn on anti-atherosclerosis unstable plaque

AIM: To investigate the effect of detoxifying herbs polygonum cuspidatum, and hawthorn, herb of promoting blood flow, on pathologic morphology and inflammatory factors in apolipoprotein E gene knockout mice, in order to approach the possible regulatory mechanism of polygonum cuspidatum and hawthorn for treating artherosclerosis (AS) unstable plaque. METHODS: The animals were divided into 7 groups (12 mice in every group). The ApoE (-/-) mice fed with high fat diet were divided into polygonum cuspidatum group, hawthorn group, polygonum cuspidatum + hawthorn group, Xuezhikang group and high fat diet model group. Moreover, ApoE (-/-) mice fed with normal diet (normal diet group) and C57BL/6J mice fed with normal diet (normal control group) were set up. After intragastric administration for 17 weeks, serum hs-CRP was detected, aorta structure was observed under light microscope and NF-κB protein expression was determined by immunohistochemistry. RESULTS: The pathological change of AS in aorta in all groups fed with high fat diet and normal diet group were observed with different degree. The changes of aortic lesion in all treatment groups were reduced. The levels of NF-κB and hs-CRP in high fat diet group were significant higher than those in normal control group and normal diet group. Serum NF-κB and hs-CRP levels decreased in every treatment group, which were significant different from those in high fat diet model group (P<0.01). Among them, the changes in polygonum cuspidatum and hawthorn groups were the best. CONCLUSION: Chinese herbs of polygonum cuspidatum and hawthorn reduce inflammatory factors NF-κB and hs-CRP expression and play a role in anti-AS formation.     

Inhibitory effect of Wendan decoction on atherosclerotic plaque formation in ApoE-/- mice by regulating expression of membrane proteins involved in reverse cholesterol transport

AIM To explore the anti-atherosclerotic mechanism of Wendan decoction based on reverse cholesterol transport. METHODS Eight-week-old apolipoprotein E gene knockout （ApoE^-/-） mice with high-fat diet and daily drug gavage were randomly divided into model group, simvastatin group, and low-, middle- and high-dose Wendan decoction groups, with 15 mice in each group. The C57BL/6 mice of the same age served as control group. The mice were weighed once every week. After 10 weeks, the mice were anesthetized with chloral hydrate. The serum were collected for lipid level examination. The atherosclerotic plaque buildup in aortic root and whole aorta was observed by HE staining and oil red O staining, respectively. The levels of proteins related to cholesterol transport, ATP-binding cassette transporter A1 （ABCA1） and caveolin-1 in the aorta, and scavenger receptor class B type I （SR-BI） and CD36 in the liver, were quantified by Western blot. RESULTS Wendan decoction at middle dose inhibited the increase in the body weight of ApoE^-/- mice fed with high-fat diet （P<0.05）. Wendan decoction at different doses significantly reduced the serum levels of triglyceride, total cholesterol and low-density lipoprotein cholesterol in the ApoE^-/- mice （P<0.05 or P<0.01）, but had no effect on serum high-density lipoprotein cholesterol level （P>0.05）. Wendan decoction at different doses inhibited the formation of atherosclerotic plaques in whole aorta of the ApoE^-/- mice （P<0.05 or P<0.01）. Middle- and high-dose Wendan decoction significantly inhibited the formation of atherosclerotic plaques in the aortic root （P<0.05）. Bedsides, Wendan decoction at different doses increased the protein level of ABCA1 and decreased the protein level of caveolin-1 in the aorta of the ApoE^-/- mice （P<0.01）. Middle- and high-dose Wendan decoction increased the liver protein level of SR-BI in the ApoE^-/- mice （P<0.01）. However, Wendan decoction at different doses had no effect on the liver protein level of CD36 in the ApoE^-/- mice （P>0.05）. CONCLUSION Wendan decoction reduces the body weight, serum lipid levels and formation of atherosclerotic plaques in ApoE^-/- mice fed with high-fat diet, and its mechanism is related to up-regulation of ABCA1 protein level in the aorta and SR-BI protein level in the liver as well as down-regulation of caveolin-1 protein level in the aorta.     

Effect of tea-polyphenols on the lipoprotein lipase and hepatic lipase activity in atherosclerosis rabbits

AIM: To investigate the effect of tea-polyphenols (TP) on the lipoprotein lipase (LPL) and hepatic lipase (HL) activity in atherosclerosis (AS) rabbits. METHODS: The rabbits feeding lipodiet were taken in 200 μg·g^-1·d^-1 TP through the experiment. The LPL and HL activity in the plasma of rabbits were detected. The LPL activity in the arteria tissue and HL activity in liver tissue were estimated with histochemistry technique. RESULTS: The LPL and HL activity in the plasma were not significantly different between premier and post experiment in AS rabbits (P＞0.05), between AS group and control group (P＞0.05). The LPL activity in the arteria tissue were not different between AS group and control group (P＞0.05). HL activity in liver tissue in AS group was significantly lower than control group (P＜0.05), but TP group was higher than AS group (P＜0.05). In TP group, the TC and LDL-c level in plasma were lower (P＜0.05), and the area of atherosclerosis plaque were smaller than those in AS group (P＜0.05). CONCLUSION: TP increased HL activity in liver tissue in AS rabbits, which correlated with decreasing the TC and LDL-c level in plasma and the area of atherosclerosis plaque.     

Effect of valsartan on atherosclerosis in the cholesterol-fed rabbits

AIM: To investigate whether valsartan inhibits the development of atherosclerosis in cholesterol-fed rabbits and its possible mechanism. METHODS: Male rabbits were fed either: (1) normal rabbit chow for 16 weeks; (2) 1.5% cholesterol diet for 16 weeks; or (3) 1.5%cholesterol diet for 16 weeks supplemented by valsartan(3 mg·kg^-1·d^-1) for the last 4 weeks. After 16 weeks, the arteries were harvested for histomorphometry and immunohistochemistry. RESULTS:Rabbits fed with cholesterol-rich diet showed higher serum lipids levels(P<0 05)than thosefed with normal diet.Treatment with valsartan did not alter serum lipid levels or arterial pressure.However,the percent age of the aortic surface atherosclerotic area were about 30% less in valsartan-treated group than that in cholesterol group,and in the number of monocyte/macrophage,20%of reduct ion was noted.In addition,the activation of nuclear factor-B and the expression of its target gene,intracellular adhesion molecule-1,were both inhibited by treatment with valsartan.CONCLUSIONS: Valsartan inhibited atherosclerotic progression. The mechanism may be related to inhibition of monocyte/macrophage proliferation and /or accumulation, and inhibition of nuclear factor-κB activation.     

Effect of high fat/cholesterol diet on lipid metabolism and intimal lesion of aorta in treble genes mutant mice

AIM: To clarify the effects of high fat/cholesterol diet on lipid metabolism and atherogenesis in treble genes mutant mice. METHODS: ApoE-/-/LDLR-/-/Leprdb/db mice were generated by cross apolipoprotein E, lower density lipoprotein receptor gene knockout mice with leptin receptor gene spontaneous point mutants. The mice were fed with high fat/cholesterol diet from 22-day-old. The total plasma cholesterol (TC), triglyceride (TG) and glucose levels were measured and pathological changes of aorta intima and liver were analyzed. RESULTS: A significant elevated TC, TG and glucose levels in plasma with progress of time in young treble gene mutant mice were observed, which were higher than that in ApoE-/-/LDLR-/- and Leprdb/db mutants. At time of only 2 weeks after fed with high fat/cholesterol diet, TC and TG levels reached (106.75±3.40) mmol/L, (9.12±1.35) mmol/L, respectively in treble gene mutant mice, 4.33- and 2.36-fold higher than those in treble genes mutants fed with normal chow diet. The levels were continuously increased until final experimental point. Intima of the aorta appeared with various injuries such as edema, desquamation of the endothelial cells, foam cell formation, rupture of IEL in local regions of root and arch areas of aorta at 2 weeks after fed with high fat/cholesterol diet. Microscopic pathological complex of significant local intima incrassation and fatty change of the liver were observed in the mutants that fed with high fat/cholesterol diet for 8 weeks. Injuries of aorta were severe than normal dietetic control group. CONCLUSION: High fat/cholesterol diet as a key dietary factor is significant aggravated lipid metabolism abnormity, promotes early damage of aorta and process of atherogenesis in the treble genes mutants.     

Inhibitory effect of recombinant human endostatin on angiogenesis in atherosclerotic plaque of rats by regulating Dll4/Notch pathway

AIM: To observe the inhibitory effect of recombinant human endostatin (rhES) on plaque angiogenesis, and to explore the regulatory mechanism of Dll4/Notch pathway in the anti-angiogenic effect of rhES. METHODS: Male Wistar rats were randomized into 3 groups:normal control group (N group), atherosclerotic model group (AS group), and rhES treated group (AS+rhES group). The rats in N group were fed a normal diet, while the remaining 2 groups were established to atherosclerotic rat model via high-cholesterol diet, intraperitoneal injection of vitamin D₃ and aortic balloon injury. The rats in AS+rhES group received intraperitoneal injection of rhES. The blood total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), C-reactive protein (CRP), interleukin-1 (IL-1) and troponin I (TnI) were measured. The atherosclerotic abdominal aortas were taken for pathological observation. Immunohistochemical staining was used to measure the density of neovessels in the plaques, which were marked by CD31. The protein levels of Dll4 and Notch1 in the aortas were analyzed by Western blot. RESULTS: The levels of blood TC, TG, LDL-C, CRP and IL-1 in AS group and AS+rhES group were much higher than those in N group (P<0.05), and no statistical difference between AS group and AS+rhES group was observed. The expression of CD31 in AS group was the highest among all groups. Compared with AS group, the density of neovessels in the plaques of AS+rhES group decreased significantly (P<0.05). The protein expression of Dll4 and Notch1 in AS group was lower than that in N group (P<0.05). Compared with AS group, the protein expression of Dll4 and Notch1 increased significantly (P<0.05). CONCLUSION: rhES has the ability to inhibit plaque angiogenesis in rats. The activation of Dll4/Notch pathway may be the mechanism of rhES in inhibiting plaque angiogenesis.     

The comparative study on SiNi-decoction and VitE against oxidative injury of vascular endothelial function and their preventive and therapeutic action on experimental atherosclerosis in rabbits

AIM: To compare effects of SiNi-decoction and Vitamin E on vascular endothelial function of experimental atherosclerosis rabbits and their therapeutic action on atherosclerosis.METHODS:The model of experimental atherosclerosis rabbits fed with forage of high lipid was established and treated in groups randomly. At the end of the experiment, samples of aorta and blood were taken and the percentage of lipid plaque area of aortic endothelium ,lipid metabolism and vascular endothelial oxidative injury (SOD activity, MDA content, NO level, endothelin concentration) of each group were analyzed. RESULTS: In comparison with model group,the percentage of the lipid plaque area of aortic endothelium and endothelial oxidative injury (except for SOD of VitE group) of SiNi-high and mid-dose group and VitE group are reduced obviously (P＜0.05),and the index of lipid metabolism of SiNi-decoction group is improved (P＜0.05). CONCLUSION:The comprehensive therapentic effects of SiNi decoction on vascular endothelial oxidative injury and atherosclerosis are superior to VitE.     

Protective effects of DAPT on rat model with atherosclerotic ischemic brain stroke by blocking Notch pathway

AIM: To investigate the protective effects of DAPT on rat model with atherosclerotic (AS) ischemic brain stroke by blocking Notch pathway. METHODS: SD rats (n=24) were randomly divided into control group and model group, and the rats in model group were fed high-fat diet for 6 weeks to establish the AS model. The AS rats were randomly divided into 3 groups (n=6 in each group):AS-sham group, AS rats with ischemia (AS-ishemia) group, and DAPT administration (AS-ishemia-DAPT) group. The histopathological changes of carotid aorta were observed by HE staining. The serum levels of triglyceride (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C) were measured by automatic biochemical analyzer. The levels of interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) were detected by ELISA. The protein levels of Notch1 and Hes1 in rat artery, and nuclear factor-κB (NF-κB) and Toll-like receptor 4 (TLR4) in rat brain were determined by Western blot. RESULTS: Notch signaling pathway inhibitor DAPT significantly reduced intimal thickening, vascular stenosis and the formation of AS plaque. Compared with AS-ischemia group, the serum levels of lipids and inflammatory factors were decreased significantly in AS-ischemia-DAPT group, and the protein levels of Notch1 and Hes1 in the rat carotid artery and NF-κB and TLR4 protein expression in rat brain were also decreased significantly (P<0.05). CONCLUSION: Blocking Notch pathway by DAPT not only improves the blood lipid levels, but also inhibits the serum inflammatory cytokine release and NF-κB/TLR4 pathway activation.     

Experimental study on induction of atherosclerotic plaque instability in rabbits after transfer of wild-type p53 gene

AIM: To study the apoptotic role of wild-type p53 in induction of plaque instability in atherosclerotic rabbits. METHODS: Fifty-four New Zealand White rabbits underwent balloon-induced abdominal aortic wall injury and then were fed on a diet of 1% cholesterol. At the end of the eighth week, the rabbits were randomly divided into two groups: group A and group B. Recombinant adenovirus carrying p53 and β-galactosidase (LacZ) genes were injected in group A and B, respectively. Two weeks later, 10 rabbits each in group A and B was killed and the remaining rabbits all underwent pharmacological triggering with injection of Chinese Russell's viper venom and histamine. RESULTS: Compared with group B, p53 gene over-expression in group A resulted in a marked increase in number of positive apoptotic cells (2.5%±0.8% vs 1.0%±0.3%, P<0.05) and a significant decrease in vascular smooth muscle cells (47.5%±6.8% vs 80.4%±10.6%, P<0.01), the thickness of the fibrous cap ［(132.9±56.7）μm vs （181.8±59.7） μm, P<0.05］ and the cap/intima-media ratio (0.20±0.18 vs 0.21±0.11, P<0.05). CONCLUSION: Transfer of human wild-type p53 genes effectively promotes apoptosis of VSMCs in atherosclerotic plaques, which makes the plaques vulnerable to rupture.     

Effects of Tongxinluo on activation of platelet in rabbit model of atherosclerosis

AIM: To study the effects of Tongxinluo on the activation of platelets in a rabbit model of atherosclerosis. METHODS: New Zealand rabbits were randomly divided into 7 groups: normal group, model group, the groups treated with high, medium and low doses of Tongxinluo micropowder (0.15, 0.3 and 0.6 g·kg^-1·d^-1), atorvastatin group (2.5 mg·kg^-1·d^-1), and aspirin group (12.5 mg·kg^-1·d^-1). The rabbits in normal group was fed with common diet for 12 weeks, and the rabbits in model group were fed with high-fat diet for 12 weeks to establish atherosclerosis model. The rabbits in the rest groups were treated with the corresponding drugs, at the same time to give high-fat diet. Fasting for 12 h after the last treatment, whole blood was collected to perform the blood routine test, and to measure serum and plasma levels of lipids, platelet factor 4 (PF4) and soluble CD62P (sCD62P). Flow cytometry was used to analyze platelet calcium ion concentration. Electron microscopy was used for platelet superfine observations, and light microscopy for observing the pathological changes. RESULTS: Compared with normal group, the levels of triglyceride (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), platelet counts, and mean platelet volume in model group were significantly elevated, and the levels of PF4, sCD62P and calcium were also significantly increased (P < 0.05). Compared with model group, except aspirin group, the levels of TG, TC and LDL-C in high, medium and low doses of Tongxinluo groups and atorvastatin group were effectively decreased. The platelet counts and mean platelet volume in all treatment groups were markedly decreased, and the serum levels of PF4, sCD62P and Ca²⁺ in platelet (P < 0.05) were reduced. In electron microscopic observation, the shape of platelet was regular and organelles distributed uniform in normal group. However, in model group, the shape of platelet was irregular, pseudopodia forming was obviously observed, and α particles and dense granules decreased, indicating that the platelet was activated. To a different extent, the platelet shape, increase in the number of α particles and dense granules were improved in treatment groups and the damage of the cytoplasm was attenuated. Through histopathological observation, the intimal was smooth and complete in normal group. In the model group, the intimal thickness markedly increased, foam cell aggregated, and plaque was formed. Compared with model group, the intimal thickening and the number of foam cells were significantly decreased, and plaque formation was not obvious in atorvastatin group and high dose of Tongxinluo group. The pathological damages in the other treatment groups were alleviated in different degrees. CONCLUSION: Tongxinluo significantly inhibits the activation of platelets in the process of atherosclerosis, and has important clinical value to delay the atherosclerotic thrombosis.     

Effects of sodium ferulate on cholesterol and triglyceride metabolism in atherosclerosis with hyperlipidemia

AIM:To investigate the effects of sodium ferulate on cholesterol and triglyceride metabolism in atherosclerosis with hyperlipidemia. METHODS:The rabbit model of atherosclerosis was produced by feeding high lipid forages. RAW264.7 foam cell and HepG2 injured cell models were established by incubation with oxidized low density lipoprotein (ox-LDL). The atherosclerotic plaque area was measured, and serum lipids were detected. The cellular lipid accumulation was examined by oil red O staining. The cellular contents of total cholesterol and cholesterol ester were quantified by high performance liquid chromatography. The hepatic lipase (HL) mRNA expression was determined by RT-PCR. RESULTS:(1) Compared with hyperlipid group, the aorta atherosclerosis plaque area and the serum triglyceride level were significantly decreased in sodium ferulate-treated rabbits, but the serum cholesterol level showed little change. (2) Compared with ox-LDL group, the HL mRNA expression in HepG2 cells was enhanced significantly in sodium ferulate-treated group, but the cellular contents of total cholesterol and cholesterol ester in RAW264.7 foam cells showed little change. CONCLUSION:Sodium ferulate inhibits the formation of atherosclerotic plaque in high-cholesterol-fed rabbits aorta. This antiatherosclerotic function may reduce serum triglyceride level through enhancing the expression of HL mRNA without influencing serum cholesterol level and foam cell formation.     

Construction of a New Zealand rabbit model of diabetic nephropathy

AIM: To establish a method to produce animal model of diabetic nephropathy (DN) in New Zealand rabbits using alloxan (ALX). METHODS: Twenty male New Zealand rabbits were randomly divided into 2 groups: 8 rabbits in control group were fed with conventional feed such as buffer solution;12 in diabetes milleuts (DM) group were fed with high-sugar and high-fat diet (conventional feed plus 5% sucrose, 5% pork fat and 1% cholesterol) for 2 weeks, then intravenous injection of ALX at 50 mg/kg was given, and another dosage of 100 mg/kg ALX was intravenously injected after 48 h. The levels of blood glucose, blood cholesterol, triglyceride, urine microalbumin, and serum creatinine were detected before and 12 weeks after the processes of modeling. After 12 weeks, the rabbits were sacrificed,and the kidneys were taken for pathological examination. RESULTS: The successful model of DN in the rabbits had the characteristics of high blood glucose, abundant urine microalbumin (P<0.01), and corresponding morphological and functional changes of the kidneys. CONCLUSION: Rabbits with high-sugar and high-fat diet plus twice intravenous injection of ALX at a total dose of 150 mg/kg (50 mg/kg and 100 mg/kg, respectively) shows low mortality and stable diabetes mellitus state. This method induces a typical DN model in 12 weeks.     

Influence of Salvia miltiorrhiza injection on lipid and ICAM-1 expression in rats with atherosclerosis

AIM: To study the effect of Salvia miltiorrhiza injection on rat atherosclerosis (AS), and elucidate the possible mechanism. METHODS: Wistar rats were fed with fat-rich diet and high dose of vitamin D₃ to induce AS, then treated with Salvia miltiorrhiza injection. Concentrations of triglyceride (TG) and total cholesterol (TC) in serum were measured by automatic serum biochemical assay. The level of ICAM-1 protein and mRNA were determined by Western blot and RT-PCR. RESULTS: Compared with the AS model group, the levels of TG and TC in serum were significantly lower in Salvia miltiorrhiza injection group (P<0.05). Western blot and RT-PCR showed that the level of ICAM-1 protein and mRNA were decreased in Salvia miltiorrhiza injection group compared with AS group. CONCLUSION: Salvia miltiorrhiza injection decreased blood lipid and reduced the ICAM-1 gene expression in rats with atherosclerosis.     

Experimental studies on anti-atherosclerosis effects of Momordica charantia L in rabbits

AIM: Anti-atherosclerosis effects of Momordica charantia L was further studied in a New Zealand rabbit atherosclerotic model at the basis of anti-inflammation and antioxidant effects. METHODS: Animals were divided into 3 groups: normal group (normal rabbit diet), atherosclerosis group(diet containing 2% cholesterol), and Momordica charantia L group(diet containing 2% cholesterol and 1.5% sarcocarp of Momordica charantia L ). Ninety days later, all animals were sacrificed. The effect of Momordica charantia L on atherosclerosis was evaluated by measuring serum lipid and total cholesterol content of artery wall, observing fatty liver degree, aorta arteriosclerotic area, and the thickness of intima. RESULTS: The level of total serum cholesterol and LDL-C in Momordica charantia L treatment group were obviously lower than those in atherosclerosis group, so were the total cholesterol content of artery wall, fatty liver degree, atherosclerotic area, intima thickness and I/M ratio, but no significantly difference was found between the two groups in TG level. The level of HDL-C in Momordica charantia L treatment group was evidently lower than that in normal control group. CONCLUSION: Momordica charantia L has an anti-atherosclerosis action in rabbits.     

Folic acid reduces monocyte chemoattractant protein-1 expession in aorta of rats with hyperhomocysteinemia

AIM: To investigate the effects of folic acid on the expression of monocyte chemoattractant protein-1 (MCP-1) in aorta of rats with hyperhomocysteinemia induced by ingestion of execess methionine (Met). METHODS: Thirty male SD rats ［(200±20） g］ were divided into 3 groups (n=10 for each group): control group (fed with normal diet), high Met group (fed with normal diet enriched by 1.7% Met) and Met plus folate group (fed with normal diet plus 1.7% Met and 0.006% folate). The animals were fed with different regiments for 45 days. Levels of total plasma homocysteine (Hcy) were detected. The expression of MCP-1 protein in aorta was detected by immunohistochemistry and Western blotting. RESULTS: The high-methionine diet resulted in a significant increase in plasma Hcy levels (P<0.01). Serum Hcy levels were significantly lower in rats fed with high-methionine plus folate-rich diet than that in rats fed with high-methionine diet (P<0.01). The expression of MCP-1 were higher in aorta of rats fed with high-methionine diet than those in control rats (46.41±4.23 vs 15.73±2.74, P<0.05). The expression of MCP-1 was significantly reduced in aorta of rats fed with high-methionine plus folate-rich diet compared with rats fed with high-methionine diet (23.12±4.40 vs 46.41±4.23, P<0.05). CONCLUSION: High methionine diet for 45 days is sufficient to induce hyperhomocysteinemia. Folate supplementation to the rats fed with the high-methenine diet prevents elevation of Hcy levels in blood, and reduces the expression of MCP-1 in aorta of rats with hyperhomocysteinemia.     

Effect of 17β-estradiol on the levels of plasma oxidized low density lipoprotein in ovariectomized rabbits

AIM: To observe the changes of plasma oxidized low density lipoprotein(oxLDL) levels of ovariectomized cholesterol-fed rabbits with or without 17β-estradiol(E₂) replacement therapy.METHODS: All rabbits were ovariectomized and fed standard chow supplemented with 1.5% cholesterol for 14 weeks. Two weeks after operation, the rabbits were randomly assigned to four groups. Three groups were treated with E₂ 1 mg, 2 mg, 4 mg respectively, the other group served as control. Serum superoxide dismutase (SOD) levels and plasma oxLDL levels were measured at 0, 3, 8, 12 weeks after hormone replacement therapy. The aortic atherosclerotic lesion areas were determined by computer. RESULTS: We found that there were striking increase of serum SOD levels ( P<0.05 ) and significant decrease in both the plasma oxLDL levels and the aortic atherosclerotic lesion areas ( P<0.01 respectively). Moreover, a positive correlation was found between plasma oxLDL levels and the areas of atherosclerotic plaque in all rabbits. CONCLUSIONS: Estrogen attenuates atherogenesis in cholesterol-fed ovariectomized rabbits. And this beneficial effect of E₂ may be duo to its lowering of plasma oxLDL level.     

Influence of Sini decoction on the proliferation and apoptosis of artery smooth muscle cells after balloon injury

AIM: To investigate the influence of Sini decoction (SND) on the proliferation and apoptosis of rabbit abdominal aorta smooth muscle cells after ballon injury and discuss the effect of vascular smooth muscle cell's (VSMCs) proliferation and apoptosis in post-percutaneous coronary intervention (PCI) restenosis (RS) and the feasibility of SND preventing post-PCI RS. METHODS: The animal model of rabbit abdominal aorta ballon injury was set up and the therapertic group was treated with SND. The shape of proliferative and apoptotic cell were investigated by electron microscope. Immunohistochemistry staining was performed using α-actin,PCNA and Cyclin E monoclonal antibodies. In situ Cell Death Detection Kit was used to identify apoptotic cells. Abdomial aorta angiography was operated in the 84th day subgroup and the stenosis degree was evalued by quantitative angiographic analysis. RESULTS: As compared with the control group, the therapeutic group displayed a lower proliferative percentage and a higher apoptosic percentage (P<0.05). Moreover, the apoptosic peek time was on the 14th day after operation,which was longer than the control group. CONCLUSION: SND effectly inhibited the proliferation of VSMCs and iuduced apoptosis in VSMCs.