Dynamic expression of S-adenosyl-L-homocysteine hydrolase under intervention of fimasartan in early stage of type 2 diabetic cardiomyopathy rats

AIM: To detect the changes of S-adenosyl-L-homocysteine hydrolase (SAHH) signaling pathway and related proteins under the intervention of fimasartan (FIM) in rats with diabetes mellitus (DM), and to explore the pathological mechanism of the occurrence and development of diabetic cardiomyopathy (DCM). METHODS: The type 2 diabetic rat model was established by injection of streptozocin after 5-week high-fat diet. The rats were randomly divided into control group, DM group, and DM+FIM group. Fasting blood glucose (FBG), total cholesterol (TC), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C) and fasting insulin (FINS) levels were tested. M-mode echocardiography was performed for determining the heart functions. High-performance liquid chromatography (HPLC) was used to detect homocysteine (Hcy), S-adenosylmethionine (SAM) and S-adenosyl-L-homocysteine (SAH). The alteration of SAHH in myocardium was determined by Western blot. RESULTS: The success rate of type 2 diabetic rat modeling was 84%. Compared with DM group, the body weight of the rats in DM+FIM group increased significantly (P<0.05), while cardiac index, left ventricular index, FBG and LDL-C were significantly reduced (P<0.05). The results of echocardiography showed that ejection fraction increased (P<0.05) in DM+FIM group. HPLC detection showed that the level of Hcy and the ratio of SAM/SAH were significantly reduced (P<0.05). The results of Western blot showed that the expression of SAHH in DM group was increased compared with control group, while that in DM+FIM group declined (P<0.01). CONCLUSION: The expression of SAHH, Hcy and other related factors may be important during the occurrence and development of early DCM, and FIM may play a role in this process as an inhibitor of SAHH.     

Effects of extract of gingko biloba on the lipid metabolism and the function of macrophages from diabetic rats

AIM: To study effect of extract of ginkgo biloba (EGb) on the lipid metabolism and the function of macrophages from diabetic rats.METHODS: Sprague-Dauley rats were divided into four groups: normal control group, high-fat group, diabetic group and EGb treatment group.At the end of experiment, the rats were sacrificed, the blood glucose, blood insulin and serum lipid were measured.The activity of superoxide dismutase (SOD), content of malondialdehyde (MDA), nitric oxide (NO) in alveolar macrophages (AM) and peritoneal macrophages (PM) were assayed.In addition, peroxisome proliferator activated receptor γ (PPARγ), CD36 mRNA expression in AM was measured by RT-PCR.RESULTS: The concentration of the blood glucose, blood insulin and total cholesterol (TC), total triglycerides (TG), low-density lipoprotein- cholesterol (LDL-C) in blood increased significantly in type 2 diabetic group.The supplement of EGb decreased blood glucose, blood insulin and TC, TG, LDL-C levels.The activity of SOD decreased, while the content of NO, MDA increased in the diabetic macrophages, the activity of SOD became increased, but the content of NO and MDA decreased in EGb-treated group.The mRNA expression level of CD36 and PPARγ in alveolar macrophages from diabetic group increased, while expression level of CD36 and PPARγ mRNA in EGb treated rats continued to rise.CONCLUSIONS: EGb corrected insulin resistance and ameliorated disturbance of lipid metabolism caused by type2 diabetes in rats.Adjustment of PPARγ and CD36 mRNA expression of as well as reduction of lipid peroxidation and NO level may be involved in this process.     

Effects of Panax notoginseng saponins on PCSK9-LDLR expression and blood lipid metabolism in golden hamsters

AIM: To explore the regulatory effect of Panax notoginseng saponins (PNS) on hyperlipidemia in golden hamsters and its mechanism. METHODS: The hamsters (n=30) were randomly divided into 3 groups:normal group, model group, and PNS group. The animals in normal group was given common feed. The animals in other groups were given high-fat diet to construct a hyperlipidemia model. After induction for 4 weeks, the drugs were given by intraperitoneal injection for another 12 weeks. After the last drug given, the serum levels of total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), aspartate aminotransferase (AST), and alanine aminotransferase (ALT) were measured by biochemical tests. The distribution and expression of proprotein convertase subtilisin/kexin type 9 (PCSK9) and low-density lipoprotein receptor (LDLR) in liver were detected by real-time PCR, immunohistochemistry and Western blot. RESULTS: Compared with normal group, the serum levels of TC, TG, LDL-C and ALT in model group were increased significantly (P < 0.05). The expression of PCSK9 was increased, while the protein level of LDLR was decreased (P < 0.05). Compared with model group, the levels of TC, TG, LDL-C and ALT in PNS group were decreased significantly (P < 0.05), PCSK9 was mainly distributed in cytomembrane with decreased expression, and LDLR was mainly distributed in the cell membrane and plasma with increased expression. HDL-C and AST had no significant change during this time. CONCLUSION: Panax notoginseng saponins reduces the blood lipid levels in golden hamsters, which may be related to the regulation of PCSK9-LDLR signaling pathway.     

Effect of ginsenoside Rb1 on liver cell pyroptosis in hyperlipidemia rats and its possible mechanism

AIM:To discuss the mechanism of ginsenoside Rb1 against liver lipid deposition by observing the effect of ginsenoside Rb1 on liver cell pyroptosis in hyperlipidemia rats. METHODS:Totally 32 healthy SPF rats were randomly divided into control group, model group, ginsenoside Rb1 group and simvastatin group. The rats in control group was given the basic feed, while the others were given high-fat diet. The rats in ginsenoside Rb1 group and simvastatin group were given corresponding drugs. The rats in control group and model group were intraperitoneal injected with equal volume of saline. Eight weeks later, the serum levels of triglyceride (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C) were tested by the automatic biochemistry analyzer. The pathological changes of the liver tissues were observed with HE staining. The protein and mRNA expression levels of pyroptosis-related factors NLRP3, caspase-1, IL-1β, IL-18 and GSDMD were detected by Western blot and RT-qPCR. RESULTS:Compared with control group, the serum levels of TC, TG and LDL-C in model group were increased significantly (P<0.01), and the HDL-C content was decreased significantly (P<0.05). The steatotic liver cells covered the visual field. The mRNA and protein expression levels of NLRP3, caspase-1, IL-1β, IL-18 and GSDMD were increased significantly (P<0.01). Ginsenoside Rb1 significantly decreased the serum levels of TC, TG and LDL-C (P<0.05), and significantly increased the content of HDL-C (P<0.01). Ginsenoside Rb1 also significantly decreased the degree of steatosis, and the number and size of lipid droplets. The mRNA and protein expression levels of NLRP3, caspase-1, IL-1β, IL-18 and GSDMD were decreased significantly (P<0.05 or P<0.01). CONCLUSION:Ginsenoside Rb1 atte-nuates liver injury and inhibits liver lipid deposition in hyperlipidemia rats by reducing the expression of hepatic pyroptosis-related factors.     

Liraglutide ameliorates liver injury of type 2 diabetic mice via micro-RNA-33-AMPK pathway

AIM: To observe the effects of liraglutide on the level of microRNA-33 (miR-33) and the expression of AMP-activated protein kinase (AMPK) and apoptosis-related proteins in mice with type 2 diabetes mellitus (T2DM), and to explore its possible mechanism. METHODS: High-fat diet and intraperitoneal injection of streptozocin were used to establish the type 2 diabetic model in C57BL/6 mice. The mice were randomly divided into 4 groups (n=15):in control group, the normal mice were subcutaneously injected with equivalent volume of saline; in model group, the T2DM mice were subcutaneously injected with equivalent volume of saline; in low-and high-dose liraglutide treatment groups, the T2DM mice were subcutaneously injected with 100 and 200 μg·kg^-1·d^-1, respectively. After 4 weeks of administration, the levels of FBG, TG, TC, HDL-C, LDL-C, ALT and AST were determined. HE staining was used to observe the pathological changes of the liver tissues. The protein level of cleaved caspase-3 in the liver tissue was detected by the technique of immunofluorescence. The protein levels of p-AMPK/AMPK and apoptosis-related proteins were detected by Western blot. The expression of miR-33 in the liver tissues was detected by real-time PCR. RESULTS: Compared with model group, the contents of FBG, TG, TC, LDL-C, ALT and AST were decreased significantly, while the content of HDL-C was increased significantly in low-dose liraglutide group and high-dose liraglutide group (P<0.05). The protein levels of phosphorylated AMPK and Bcl-2 were up-regulated significantly, and the expression of cleaved caspase-3 was down-regulated significantly (P<0.05). The level of miR-33 was decreased significantly (P<0.01). CONCLUSION: Liraglutide alleviates liver injury in type 2 diabetic mice, and the mechanism may be associated with reducing the level of miR-33 and increasing the phosphorylation of AMPK in the liver tissues, thereby inhibiting hepatocyte apoptosis.     

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.     

Expression of scavenger receptor B1 (SR-B1) in the liver of high fat and sugar diet-induced diabetic mice

AIM: To investigate serum lipid and the expression of SR-B1 in the livers of diabetic mice. METHODS: Ten normal diet, female C57BL/6J mice, fifteen high fat and sugar diet female C57BL/6J mice, five fed 8 weeks and ten fed 16 weeks were used in the experiment. Serum total cholesterol (TC), triglycerides (TG), high density lipoprotein cholesterol (HDL-C), fasting blood glucose (FBG), insulin (INS) and the expression of SR-B1 in the livers were measured. RESULTS: 1. In the high fat and sugar diet mice, serum TC and FBG at 16 weeks were significantly higher than that in normal diet mice (P<0.05). 2. The expression of SR-B1 protein in the liver of high fat and sugar diet mice was the higher than that in normal mice, and the SR-B1 expression in the liver of the mouse fed 16 weeks was also higher than that fed 8 weeks. CONCLUSION: The expression of SR-B1 protein in the liver of type 2 diabetes mice is higher than that in normal mice, perhaps it is related to the decrease in serum HDL-C.     

Changes of liver lipid metabolism-related PPAR-γ/LXR-α/ABCG1 pathways and inflammatory factors in atherosclerotic mice and role of Huayu-Qutan recipe

AIM To observe the changes of liver lipid metabolism-related peroxisome proliferator-activated receptor-γ (PPAR-γ)/liver X receptor-α (LXR-α)/ATP-binding cassette transporter G1 (ABCG1) signaling pathways and inflammatory factors in mice with atherosclerosis (AS), and to investigate the effects of Huayu-Qutan recipe (HYQT) on hepatic lipid metabolism and inflammatory response and the mechanisms. METHODS ApoE^-/- mice (n=24) were randomly divided into model group, HYQT group and simvastatin group, and C57BL/6J mice (n=8) were used as control group. Except for the control group, the mice in other groups were given high-fat diet. After 12 weeks of modeling, the mice in HYQT and simvastatin groups were intragastrically given the corresponding drugs, and the mice in control and model groups were given the same volume of normal saline. After 8 weeks, 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 an automatic biochemical analyzer. HE and oil red O staining was used to observe liver histopathological and lipid changes. The hepatic levels of free fatty acid (FFA), TG, tumor necrosis factor-α (TNF-α), Toll-like receptor 4 (TLR4) and interleukin-1β (IL-1β) were detected by ELISA. The protein expression of PPAR-γ, LXR-α and ABCG1 was determined by Western blot. RESULTS Compared with control group, the serum levels of TC, TG and LDL-C in model group were significantly increased (P<0.01), and the HDL-C content was significantly decreased (P<0.01). Liver steatosis, cell size augmentation and lipid deposition were obvious, and liver FFA and TG levels were significantly increased (P<0.01). The liver levels of TLR4, TNF-α and IL-1β were significantly increased (P<0.01), while the protein expression of PPAR-γ, LXR-α and ABCG1 was significantly decreased (P<0.05 or P<0.01). Compared with model group, the serum levels of TC, TG and LDL-C in simvastatin group and HYQT group were significantly decreased (P<0.05 or P<0.01), and the HDL-C content was significantly increased (P<0.01). Liver steatosis was weakened, and liver lipid deposition and FFA and TG levels were significantly decreased (P<0.05 or P<0.01). The liver levels of TLR4, TNF-α and IL-1β were significantly decreased (P<0.01), while the protein expression of PPAR-γ, LXR-α and ABCG1 was significantly increased (P<0.05 or P<0.01). CONCLUSION Huayu-Qutan recipe may exert anti-AS effect by regulating liver PPAR-γ/LXR-α/ABCG1 pathways and attenuating liver TRL4-mediated inflammatory responses.     

Effects of gypenosides on PCSK9 gene expression and blood lipids lowered by simvastatin

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 simvastatin 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 simvastatin 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 cholesterol (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. RESULTS: 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, especially in combined group. Compared with model group, the mRNA expression levels of PCSK9 and LDLR in simvastatin group were obviously increased, while the mRNA expression levels of PCSK9 in GPs group and combined group were obviously 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 PCSK9 and LDLR in simvastatin group was obviously increased, while the protein expression levels of PCSK9 in GPs group and combined group were obviously reduced, and the LDLR protein levels were obviously increased (P<0.05). CONCLUSION: Gypenosides inhibit the expression of PCSK9 and increase 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 PCSK9 in the liver.     

Effect of puerarin on myocardial injury in KKAy diabetic mice

AIM:To observe the effect of puerarin on myocardial injury according to the time of occurrence of myocardial injury in the development of type 2 diabetic mice. METHODS: The serum levels of glucose (GLU), triglyceride (TG), total cholesterin (TC), low density lipoprotein-cholesterol (LDL-C) and high density lipoprotein-cholesterol (HDL-C) in 17-week, 20-week, 24-week, 28-week KKAy mice were detected by automatic biochemical methods. The apoptotic percentage of cardiomyocytes was examined by flow cytometry. The expressions of bax and bcl-2 mRNA in cardiomyocytes were detected by RT-PCR. Caspase-3 expression in cardiomyocytes was determined by immunohistochemical staining. RESULTS: Compared to normal control mice, not only GLU level increased, but also the levels of TG, TC, LDL-C, HDL-C in 20-week, 24-week and 28-week KKAy mice increased apparently (P<0.01). Apoptosis of cardiomyocytes in KKAy mice began to show up at 28-week. The expression of bax mRNA increased and expression of bcl-2 mRNA reduced. At the same time, the expression of caspase-3 increased. Puerarin obviously decreased the apoptotic percentage of cardiomyocytes, reduced the expression level of bax mRNA, improved the expression level of bcl-2 mRNA (P<0.01), inhibited the expression of caspase-3 (P<0.01). CONCLUSION:Myocardial injury exits in type 2 diabetic mice. Mitochondria apoptotic pathway might participate in the hurting course.     

Correlation between TAFI and blood fat and coagulation in the process of atherosclerosis

AIM: To investigate the relationship between the thrombin-activatable fibrinolysis inhibitor (TAFI) level in plasma and atherosclerosis, the TAFI level in plasma and blood fat and blood clotting index.METHODS: Totally 40 healthy male Wistar rats were randomly divided into 4 groups (n=10), control group, high lipid group, high lipid +vitamin D3 overload group, and high lipid +vitamin D3+endothelium injure group by treating the animals with normal diet, high lipid, high lipid+ vitamin D overload, and high lipid+vitamin D overload+endothelium injury, respectively, for inducing three stages of AS in rats. Then, the total cholesterol (TC), total triglyeride (TG), high density lipoprotein (HDL), low density lipoprotein (LDL), and prothrombin time (PT), activated partial thromboplasin time (APTT), fibrinogen (Fib), the activity of TAFI were measured.RESULTS: TC, TG, LDL-C, Fib and the activity level of TAFI in plasma in three model groups increased gradually compared with the control (P＜0.01). HDL-C, PT and APTT in plasma of three model groups decreased gradually compared with the control (P＜0.01 or P＜0.05). The activity of TAFI in plasma had positive correlation with TG, TC and Fib.CONCLUSION: The activity of TAFI increases in the progress of atherosclerosis. The activity of TAFI in plasma has a correlation with blood fat and coagulation, which indicates that TAFI might participate in the process of atherosclerosis, and TAFI is one of etiological factors of atherosclerosis.     

Serum levels of inflammatory factors and adiponectin in type 2 diabetic retinopathy patients

AIM: To investigate the serum levels of inflammatory factors and adiponectin in type 2 diabetic retinopathy (DR) patients.METHODS: One hundred and ten cases of type 2 diabetic patients were divided into 3 groups: no diabetic retinopathy group (DM, n=35), non-proliferative diabetic retinopathy group (NPDR, n=45), and proliferative diabetic retinopathy group (PDR, n=30). Other 40 normal persons served as controls (NC group). The physical examinated was performed for each patient. Serum levels of fasting plasma glucose (FPG), glycated hemoglobin A1c (HbA1c), 2 h postprandial plasma glucose (2hPG), fasting insulin (FINS), total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), adiponectin, intercellular adhesion molecule-1(ICAM-1), tumor necrosis factor-α (TNF-α) and high-sensitivity C-reactive protein (hs-CRP) were measured. Insulin resistance index (HOMA-IR) was also calculated.RESULTS: The systolic blood pressure, body-mass index, waist-hip ratio, serum levels of TG, LDL-C, FPG, 2hPG, HbA1c, ICAM-1, TNF-α, hs-CRP and HOMA-IR were significantly higher in DM group, NPDR group and PDR group than those in NC group (P<0.05). The systolic blood pressure, serum levels of ICAM-1, TNF-α, hs-CRP and HOMA-IR were higher in NPDR group and PDR group than those in DM group (P<0.05). The serum concentration of adiponectin was lower in DM group, NPDR group and PDR group than that in NC group (P<0.05), and that was also lower in NPDR group and PDR group than that in DM group (P<0.05). The negative correlations between adiponectin and ICAM-1 (r=-0.735,P<0.01), TNF-α (r=-0.781,P<0.01), hs-CRP (r=-0.768, P<0.01) or HOMA-IR (r=-0.752, P<0.01) were observed. The relationships between HOMA-IR and ICAM-1 (r=0.857,P<0.01), TNF-α (r=-0.906, P<0.01) or hs-CRP (r=-0.888,P<0.01) were positive.CONCLUSION: The results suggest that inflammatory refactors and adiponectin play important roles in the pathophysiology and progression of DR. The protective effects of adiponectin on DR may be related with its anti-inflammatory reactions to improve insulin resistant.     

Serum lipid levels and ApoB gene Xba I and 3'-VNTR polymorphisms in longevous elderly Han population in Zhejiang

AIM: To study the levels of serum lipids and the effects of apolipoprotein B (ApoB) gene Xba I-restriction fragment length polymorphism (RFLP) and 3'-variable-number tandem repeat (VNTR) polymorphism on serum lipid and apolipoprotein levels in longevous elderly Han population in Zhejiang. METHODS: Physical and laboratory examinations were performed on longevous elders, children of longevous elders, normal control people and children of non-longevous elders, and the Xba I-RFLP and 3'-VNTR polymorphism in ApoB gene were genotyped. RESULTS: The serum levels of triglyceride (TG), low-density lipoprotein cholesterol (LDL-C) and ApoB were negatively correlated with longevity (P<0.05), while the level of high-density lipoprotein cholesterol (HDL-C) was positively correlated with longevity (P<0.01). The levels of total cholesterol (TC), LDL-C and ApoB were higher and the HDL-C level was lower in the people with Xba I-RFLP X⁺X^- genotype than those in the people with Xba I-RFLP X^-X^- genotype (P<0.01). The levels of TC, TG, LDL-C and ApoB were higher and the HDL-C level was lower in the people with 3'-VNTR large allele than those in the people with 3'-VNTR minor allele (P<0.01). CONCLUSION: High TG, LDL-C and ApoB levels and low HDL-C level are not conductive to longevity. Serum lipid levels in the people with Xba I-RFLP X^-X^- genotype or 3'-VNTR minor allele are healthy and conductive to longevity.     

Effect of Xuefuzhuyu decoction on cardiomyopathy in type 2 diabetic rats

AIM: To observe the pathologic changes of cardiomyopathy in type 2 diabetic rats and the therapeutic effect of Xuefuzhuyu decoction.METHODS: The diabetic model was established by feeding the animals with high-fat diet and injecting a middle dose of streptozotocin (50 mg/kg) intraperitoneally in 42 Wistar male rats. After 8 weeks, the damage of the heart in the model animals was detected by electrocardiogram and echocardiography, and the serum level of glucose, total cholesterol and triglyceride were determined by the methods of clinical chemistry. The content of collagen was quantified by Masson staining. The apoptosis of cardiomyocytes was measured by TUNEL apoptosis kit. The structures of myocardial damage were observed under light and electronic microscopes.RESULTS: (1) Compared with normal group at the same time points, the contents of serum glucose, triglyceride and cholesterol in model group increased (P<0.05). At the 11th and 14th weeks, the thickness of LVDS was significantly increased (P<0.01), the structure of myocardial tissues was severely damaged and collagen fiber content increased obviously (P<0.01). The cell apoptosis was also increased. (2) Compared with control group at the same time points, the contents of serum glucose, cholesterol and triglyceride in Xuefuzhuyu decoction group significantly decreased (P<0.05). The thickness of LVDS at the 11th and 14th weeks was decreased (P<0.05) and LVM at the 14th week became significantly thinner (P<0.01). The damage of the myocardium and subcellular structure was slighter and the content of collagen was lower than that in control group (P<0.05). The cell apoptosis was also attenuated.CONCLUSION: The levels of blood glucose, total cholesterol and triglyceride and the content of collagen fibers increase when diabetic cardiomyopathy develops, with more cell apoptosis and severe damage in the cardiac structure. Xuefuzhuyu decoction decreases the level of blood lipid in diabetic cardiomyopathy, alleviates the pathological changes of myocardial fibrosis and delays the progression of diabetic cardiomyopathy.     

Effects of resveratrol on cardiac dysfunction and ASMase-ceramide pathway in type 2 diabetic rats

AIM:To investigate the effects of resveratrol (RSV) on cardiac dysfunction and acid sphingomyelinase (ASMase)-ceramide pathway in diabetic rats. METHODS:Type 2 diabetes mellitus (T2DM) model was established by a high-fat diet combined with STZ intraperitoneac injection (30 mg/kg). SD rats (n=20) were randomly divided into control group, T2DM group; T2DM+RSV group (diabetic rats were given resveratrol at 100 mg·kg·d^-1 by intragastric administration for the treatment) and RSV group (some of control rats were selected to give the same dose of RSV for drug control group). The M-mode Doppler ultrasonography was performed to observe the changes of cardiac function and structure in the rats. The levels of serum glucose, lipid and superoxide dismutase (SOD) activity, malondialdehyde (MDA) content in heart tissues were measured. Oil red O staining and Sirius red staining were performed to observe lipid accumulation and cardiac fibrosis in heart tissues. The cardiac ceramide concentration in diabetic rats was analyzed by high-performance liquid chromatography. The protein expression of ASMase and peroxisome proliferator-activated receptor-γ co-activator 1α (PGC-1α) in the hearts was determined by Western blot. RESULTS:Compared with the control group, the levels of fasting blood glucose, total cholesterol (TC), triglyceride (TG) and low-density lipoprotein cholesterol (LDL-C) were significantly elevated in T2DM group. The values of ±dp/dt_max, fractional shortening and ejection fraction were declined, and the left ventricle internal dimension at end-systole (LVIDs) and left ventricle internal at end-diastole (LVIDd) were increased. Furthermore, increased MDA content and more lipid accumulation were also observed in diabetic hearts, while the SOD activity, ATP content and PGC-1α expression were reduced in diabetic hearts. However, all these parameters were reversed by addition of RSV, concomitant with decreased ASMase expression and ceramide content. CONCLUSION:RSV dramatically alleviates diabetes-induced cardiac dysfunction and cardiac fibrosis, which may attribute to inhibition of ASMase-ceramide activation.     

Protective effect of curcumin on myocardium in diabetic rats

AIM: To study the effects of curcumin (Cur) on diabetic cardiomyopathy (DCM) in rats. METHODS: Male Wistar rats (n=75) were divided into control group and diabetes model group, in which the rats were fed with high-fat diet and then intraperitoneally injected with streptozotocin (STZ, 40 mg/kg). Fasting blood glucose was measured 72 h and 1 week after STZ injection. The diabetic rats were diagnosed when sustained fasting blood glucose levels ≥ 11.6 mmol/L. The diabetic rats were randomly divided into DCM group, DCM+Cur 100 mg/kg group and DCM+Cur 200 mg/kg group. After treatment for 16 weeks, glutathione peroxidase (GSH-Px) activity and malondialdehyde (MDA) level were measured, and the level of cardiac troponin I (cTnI) in the serum was determined by enzyme-linked immunosorbent assay. The protein expression of protein kinase C (PKC) was detected by Western blotting. RESULTS: Curcumin significantly decreased the blood glucose level, increased the body weight, inhibited MDA content and up-regulated the GSH-Px activity in the diabetic rats. Furthermore, curcumin treatment inhibited the diabetes-induced protein expression of PKC. CONCLUSION: Curcumin may have a protective effect on diabetic cardiomyopathy by attenuating oxidative stress.     

Effect of tanshinone ⅡA on liver lipid deposition and ferroptosis-related protein expression in ApoE-/- mice

AIM To observe the effect of tanshinone ⅡA on liver lipid deposition and ferroptosis-related protein expression in ApoE^-/- mice. METHODS Thirty-two ApoE^-/- mice were randomly divided into model group, high-dose (60 mg/kg) tanshinone ⅡA group, low-dose (30 mg/kg) tanshinone ⅡA group and simvastatin group, and C57BL/6J mice (n=8) were used as normal control group. The mice in normal control group were given the basic feeding, while the others were given high-fat diet. The mice in tanshinone ⅡA groups and simvastatin group were given corresponding drugs. The mice in normal control group and model group were intraperitoneally injected with equal volume of saline. Eight weeks later, the serum levels of triglyceride (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C) were tested by automatic biochemistry analyzer. The liver tissues were stained with HE and oil red O. The contents of reactive oxygen species (ROS) and glutathione (GSH) in liver tissues of the mice were measured by commercially available kits. The liver glutathione peroxidase 4 (GPX4) and p53 were detected by immunohistochemical method. The protein and mRNA expression levels of ferroptosis-related factors GPX4, xCT/SLC7A11, p53 and ferritin heavy chain 1 (FTH1) were determined by Wes automatic Western blot quantitative analysis system and RT-qPCR. RESULTS Compared with normal control group, the serum levels of TC, TG and LDL-C in model group were increased significantly (P<0.05 or P<0.01), and HDL-C did not change significantly. The fat vacuoles were clearly visible in liver tissue. The content of ROS in liver tissue was increased significantly,and GSH was decreased significantly (P<0.01). The mRNA and protein expression levels of p53 were increased significantly, and GPX4, xCT/SLC7A11 and FTH1 were decreased significantly (P<0.05 or P<0.01). Compared with model group, tanshinone ⅡA significantly decreased the serum levels of TC, TG and LDL-C (P<0.05 or P<0.01), and HDL-C did not change significantly. High-dose and low-dose tanshinoneⅡA also significantly decreased the degree of steatosis, and the size of lipid droplets. The content of ROS in liver tissues was decreased significantly, and GSH was increased significantly (P<0.01). The mRNA and protein expression levels of GPX4, xCT/SLC7A11 and FTH1 were increased significantly, and p53 were decreased significantly (P<0.05 or P<0.01). CONCLUSION Tanshinone ⅡA reduces liver lipid deposition and lipid peroxidation damage in ApoE^-/- mice, which may be related to the intervention of ferroptosis-related proteins in the liver cells.     

Yiqi-Yangyin recipe attenuates myocardial ischemia-reperfusion injury in diabetic rats by activation of ERK/Nrf2/HO-1 pathway

AIM: To explore the effect of Yiqi-Yangyin recipe on myocardial ischemia-reperfusion injury (MIRI) in rats with diabetes mellitus (DM) and the possible mechanism. METHODS: The rats were divided into normal group (control group), DM sham operation (DM-S) group, DM+MIRI group, low-, medium-and high-dose Yiqi-Yang-yin recipe (TL, TM and TH) groups (7.5, 15 and 30 g/kg decoction of Yiqi-Yangyin recipe by gavage), and Nrf2 inhibitor (bardoxolone methyl) group (30 mg/kg bardoxolone methyl by intragastric administration). The gavage volume was 1 mL/kg. There were 15 rats in each group, and they were administered continuously for 7 d. The tail vein blood was collec-ted after the last administration to detect the blood sugar and lipid levels in the rats. The serum levels of cardiac troponin I (cTnI), tumor necrosis factor-α (TNF-α), interleukin (IL)-1β and IL-10 were measured by ELISA. Echocardiography was used to detect the changes of cardiac function in the rats after blood collection. After cardiac function test, the rats were sacrificed to obtain cardiac tissues, and the volume changes of myocardial infarction were assessed by triphenylte-trazole chloride staining. The histopathological changes of myocardium was observed by HE staining. The cardiomyocyte apoptosis was determined by TUNEL assay. The protein levels of phosphorylated extracellular signal-regulated kinase (p-ERK), nuclear factor E2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) in the myocardium were determined by Western blot. The myocardial activity of superoxide dismutase (SOD) was measured by nitro blue tetrazolium method, the content of malondialdehyde (MDA) was tested by thiobarbituric acid method, and the production of reactive oxygen species (ROS) was analyzed by iron ion reduction method. RESULTS: Compared with control group, the levels of fasting blood glucose (FBG), total cholesterol (TC) and triglyceride (TG) in DM-S group and DM+MIRI group were significantly elevated, while the level of high-density lipoprotein cholesterol (HDL-C) was significantly lowered (P<0.05). Compared with DM-S group and DM+MIRI group, the levels of FBG, TC, TG in TL, TM, TH and bardoxolone methyl groups were significantly decreased, while HDL-C level was significantly increased (P<0.05). Compared with control group and DM-S group, heart rate (HR) and left ventricular end-diastolic pressure (LVEDP) were increased in DM+MIRI group, mean arterial pressure (MAP), left ventricular systolic pressure (LVSP) and left ventricular ejection fraction (LVEF) were decreased, serum levels of cTnI, TNF-α, IL-1β and IL-10 were increased, the myocardial infarction volume percentage was increased, the myocardial cell breakage and necrosis were increased, the myocardial cell apoptotic rate was increased, the protein levels of p-ERK1/2, Nrf2 and HO-1 were decreased, MDA and ROS levels were increased, and the activity of SOD was decreased (P<0.05). Compared with DM+MIRI group, HR and LVEDP were decreased in TL, TM, TH and bardoxolone methyl groups, MAP, LVSP and LVEF were increased, the serum levels of cTnI, TNF-α, IL-1β and IL-10 were decreased, the myocardial infarction volume percentage was decreased, myocardial cell breakage and necrosis were decreased, myocardial cell apoptotic rate was decreased, the protein levels of p-ERK1/2, Nrf2 and HO-1 were increased, the MDA and ROS levels were decreased, and the activity of SOD was increased (P<0.05). CONCLUSION: Yiqi-Yangyin recipe protects the myocardial tissue of DM+MIRI rats from injury and reduces the oxidative stress level, which may be achieved by activating ERK/Nrf2/HO-1 pathway.