ABSTRACT
AIM:To explore the effect of gypenosides ( GPs) on PCSK9 gene expression in hyperlipidemic rat liver and the blood lipids lowered by simvastatin .METHODS: Healthy male SD rats ( n=60 ) were randomized into 5 groups:normal control group , hyperlipidemic model group , simvastatin group , GPs group and GPs combined with simvasta-tin group ( combined group ) .The rats in all groups were fed high-fat diet except normal control group which were fed with ordinary diet.The rats in control group and hyperlipidemic model group were gavaged with 0.3%CMC-Na every day.The rats in GPs group were gavaged with GPs at 160 mg? kg-1? d-1 .The rats in simvastatin group were gavaged with simvas-tatin at 5 mg? kg-1? d-1 .The rats in combined group were gavaged with GPs and simvastatin .The experiment lasted for 8 weeks.The rats were anesthetized with chloral hydrate , and abdominal arterial blood samples were collected to detect the total cholesterol ( TC) , triglyceride ( TG) , low-density lipoprotein cholesterol ( LDL-C) and high-density lipoprotein cho-lesterol ( HDL-C) .The body weight and the wet weight of the livers were measured , and the liver index was calculated . The pathological changes of the livers were observed under microscope with HE staining .The expression of PCSK9 and low-density lipoprotein receptor ( LDLR) at mRNA and protein levels was determined by real-time PCR and Western blot .RE-SULTS:The model of hyperlipidemia rats was established successfully .Compared with model group , the levels of TC , TG and LDL-C in simvastatin group, GPs group and combined group were obviously decreased (P<0.05), and the HDL-C levels were obviously upregulated (P<0.05).Compared with model group, the liver indexes in simvastatin group, GPs group and combined group were obviously decreased (P<0.05).The pathological changes of the liver tissues showed that hepatic adipose appeared in model group , and that in simvastatin group and GPs group had different degrees of relief , espe-cially in combined group .Compared with model group , the mRNA expression levels of PCSK 9 and LDLR in simvastatin group were obviously increased , while the mRNA expression levels of PCSK 9 in GPs group and combined group were obvi-ously decreased (P<0.05), and the mRNA expression of LDLR in combined group was obviously increased (P<0.05). Compared with model group , the protein expression of PCSK 9 and LDLR in simvastatin group was obviously increased , while the protein expression levels of PCSK 9 in GPs group and combined group were obviously reduced , and the LDLR pro-tein levels were obviously increased (P<0.05).CONCLUSION:Gypenosides inhibit the expression of PCSK9 and in-crease the expression of LDLR in the liver .The combination of gypenosides and simvastatin promotes the lipid-lowering effect of simvastatin and attenuates hepatic steatosis , which may be related to inhibiting the expression of PCSK 9 in the liv-er.
ABSTRACT
This study was aimed to explore whether gypenosides (GPs) can inhibit the expression of miRNA-122 and regulate the lipid metabolism enzyme activity to play a role in lipid-lowering effect. A total of 48 healthy male SD rats were randomly divided into 4 groups, which were the normal control group (C), hyperlipidemic model group (M), simvastatin group (S) and the GPs group (G). All groups were fed with high-fat diets except the normal control group which was fed with normal diets. The GPs, which were dissolved in 0.3% sodium carboxymethyl cellulose (CMC-Na) solution, were given by the intragastric administration. The C group and M group were given 0.3% CMC-Na solution (1 mL/100 g) daily. The G group was given 160 mg·kg-1 of GPs daily. The S group was given 5 mg·kg-1 of simvastatin daily. The experiment was continued for 8 weeks. After the last medication, rats were fasted for 12 hours. Rats were anesthetized with chloral hydrate (7%). Abdominal arterial blood samples were collected to detect the total cholesterol (TC), triglyceride (TG), high density lipoprotein cholesterol (HDL-C) and low density lipoprotein cholesterol (LDL-C). The wet weight of liver was weighed and the liver index was measured. The liver total RNA was extracted to determine the expression of miRNA-122 by the real-time PCR. The homogenates of liver tissues were prepared for the determination of hepatic lipase (HL), lipoprotein lipase (LPL) and HMG-CoA reductase activity. Cholesterol micelle formation experiments were implementedin vitro. The results showed that compared with the normal control group, TC, TG and LDL-C levels of the model group were significantly increased (P< 0.01), while the HDL-C levels in each group were obviously decreased (P< 0.05). Compared with the model group, TC, TG and LDL-C levels of the S group and G group were obviously decreased (P< 0.05), and the HDL-C level was obviously increased (P< 0.05). Compared with the model group, the liver indexes of the S group and G group were obviously decreased (P< 0.05). Compared with the hyperlipidemia model group, the expressions of miRNA-122 of the S group and G group were significantly reduced (P< 0.05). Compared with the hyperlipidemia model group, the activity of HMG-CoA reductase was obviously reduced in the S group and G group (P< 0.05), but the HL and LPL activities were obviously increased (P< 0.05). GPs can inhibit the formation of cholesterol micelles to some extent. It was concluded that GPs can effectively reduce the blood lipid level in hyperlipidemic rats, in order to relieve the hepatic fatty lesions. Its lipid-lowering mechanism was related to its inhibition of miRNA-122 expression and regulation of lipid metabolism enzyme activity, as well as the inhibition on the formation of cholesterol micelles.
ABSTRACT
OBJECTIVE: To study the effect of hesperidin and rutin on oxidative modification of high density lipoprotein (HDL) in vitro. METHODS: HDL was isolated from healthy human plasma by sequential ultracentrifugation, and was oxidized by copper ions. The inhibitory effects of hesperidin and rutin on HDL oxidative modification were valued by the formation of malondialdehyde (MDA). RESULTS: Hesperidin and rutin significantly inhibited copper-induced oxidation of HDL in a dose-dependent manner. CONCLUSION: Both hesperidin and rutin can prevent HDL from copper-induced oxidative modification in vitro. This result suggests that they might have antiatherogenic effect.
ABSTRACT
Objective To evaluate the antioxidant effect of hesperidin and its effect on transcription of monocyte chemoattractant protein 1 (MCP 1) in rabbits with dietary atherosclerotic lesions. Methods (1) Low density lipoprotein (LDL) was isolated from healthy human plasma by sequential ultra centrifugation and oxidized by copper. The contents of malondialdehyde (MDA) were measured at different dosages of the drug and at different reaction time. (2) Atherosclerotic model of rabbits was established by feeding rabbits with high lipid diet and immune injury. A total of 18 rabbits were divided randomly into three groups: control group, model group, and hesperidin group ( n =6 in each group). Rabbits in the control group were fed with common diet, those in the model group with high lipid diet, and those in the hesperidin group with high lipid diet plus hesperidin. After 10 experimental weeks, blood samples were collected from the marginal ear veins for the detection of the contents of MDA and nitric oxide (NO). The rabbits were sacrificed for the isolation of the thoracic aorta. MCP 1 mRNA transcription in the thoracic aorta was detected by RT PCR. Results Hesperidin could significantly inhibit MDA production in a dose dependent manner in vitro ( P
ABSTRACT
Objective To study the effects of monocyte chemotactic protein-1(MCP-1) on the growth of human umbilical vein endothelial cells (hUVEC). Methods hUVEC were cultured in vitro and identified. hUVEC that grew vigorously were stimulated for 24 h or 48 h respectively with MCP-1(0.1, 1.0, 10, and 100 ?g/L). The survival rate of hUVEC was first detected by MTT assay. The cell cycle and DNA content were detected and analyzed by flow cytometry. Results hUVEC were isolated from human umbilical veins and cultured, and then identified by immunofluorescence and immunohistochemistry with factor Ⅷ and KDR. MCP-1 induced the apoptosis of hUVEC in a dose-dependentmanner and a time-dependentmanner (P
ABSTRACT
Objective To investigate the injuries caused by cholesterol to the vascular endothelial cells (VECs). Methods Different dosage of cholesterol (6.25,12.5,25.0,50.0 mg/L) was used on human umbilical endothelial cell line,ECV304,respectively. LDH activity,nitric oxide and the nitric oxide synthetase activity in the supernatant of cell culture were detected. The concentration of MCP-1 protein in cell culture was detected by ELISA. Results As compared with the normal control cells,a significant increase of LDH activity was found in the cells treated with 50.0 mg/L cholesterol. The NO level decreased in the cells treated by 25.0 or 50.0 mg/L cholesterol. When treated by cholesterol at dose of 6.25,12.5,25.0 or 50.0 mg/L respectively,the NOS activity was greatly decreased and MCP-1 protein was significantly increased in a dose-dependent manner. Conclusion Cholesterol of high concentration could directly injure the structure and partial function of VECs.
ABSTRACT
Aim To study the inhibition of genistein on proliferation and transcription of c-fos mRNA in human umbilical vascular smooth muscle cells(hUVSMC) induced by monocyte chemotactic protein-1(MCP-1). Methods Growth-arrested hUVSMC were stimulated with MCP-1(10 ?g?L-1) prior to co-treatment with different concentrations of genistein (10,30,90 ?mol?L-1). The response of hUVMSC to these treatments was observed in comparison with that of control group. The proliferation of hUVMSC was evaluated by cell counting. The expression of c-fos mRNA was detected by RT-PCR. Results Low concentration of genistein(10 ?mol?L-1) inhibited the proliferation of hUVSMC and high concentration of genistein(30,90 ?mol?L-1) inhibited the expression of c-fos in hUVSMC induced by MCP-1. Conclusions Genistein could suppress the proliferation of hUVSMC induced by of MCP-1. Its mechanisms may involve the down-regulation of c-fos mRNA expression.
ABSTRACT
AIMTo study the influences of hesperidin on the regula tion of serum lipids levels by simvastatin and its mechanism. METHODS Wistar rats were divided randomly into five groups:control group,model g roup,simvastatin group(SV group), low dose hesperidin +SV group(LDHS group) and high dose hesperidin+SV group(HDHS group).The control group were fed with common diet. The model group were fed with high lipid diet. Other groups were fed with diet containing high lipid,5 mg?kg -1 SV and different doses of hesperid in accordingly. After 8 experimental weeks,the serum lipids levels and CYP4503Am RNA expression in livers and small bowels of the rats were detected. RE SULTSAfter 8 weeks of high lipid diet, the levels of TC,TG and LDL-C in model groups increased significantly (P
ABSTRACT
Objective To study the effects of PDTC on cholesterol induced C-reactive protein gene expression in L-02 cell line.Methods Human hepatocyte cell line L-02 was cultured in vitro;growth-arrested cells were divided into 3 groups,cholesterol group,PDTC+cholesterol group and control group.After 48 h incubation,western blot and immunoturbidimetry assays were carried out to detect intracellular and secreted C reactive protein expression.Results Cholesterol stimulated CRP gene expression in L-02(P
ABSTRACT
Objective: To study the effect of genistein(Gen) on expression of monocyte chemotactic protein-1 ( MCP-1) mRNA and MCP-1 induced by oxidized low density lipoprotein (ox-LDL) in human umbilical venous smooth mulscle cells (hUVSMC). Methods: Gen at different doses (1.0?10-5、3.0?10-5、9.0?10-5mol/L) were used to observe the effect on expression of MCP-1 mRNA and MCP-1 induced by ox-LDL in hUVSMC cultures and compared with the effect of 17b-estradiol(17b-E). RT-PCR and ELISA were used to measure expression of MCP-1 mRNA and MCP-1 respectively. Results: Gen significantly inhibited the expression of MCP-1 mRNA and MCP-1 in cell culture supernant . There was no significant difference in the inhibitory effect between high concentration of Gen and physiological level of 17b-E . Conclusion: Gen can down-regulate hUVSMC expression of MCP-1 mRNA and MCP-1. It suggests that this may be the important antiatherogenic mechanism of Gen.