mRNA expression of insulin receptor and leptin receptor in liver of nonalcoholic fatty liver disease from diabetic rats

AIM: To observe the pathologic changes of liver in diabetic rats and to investigate the role of mRNA expression of insulin receptor and leptin receptor in the pathogenesis of nonalcoholic fatty liver disease (NAFLD). METHODS: Twenty male Sprague-Dawley rats were divided randomly into two groups: normal control group and diabetic group. After fed with high-fat diet for 4 weeks, diabetic rats were injected with streptozotocin at a dosage of 30 mg/kg intraperitoneally to induce NAFLD model of type 2 diabetes mellitus. Then the diabetic animals were fed with high-fat diet continuously for 12 weeks. At the end of the experiment, the rats were sacrificed, the concentrations of blood glucose, serum lipid, ALT and AST were measured biochemically. The levels of serum leptin and serum insulin were detected by enzyme-linked immunosorbent assay (ELISA) and radio immunoassay (RIA), respectively. The pathologic changes of liver were observed under light microscopy (LM) stained with HE, Sudan Ⅲ and Masson trichrome staining, respectively. The ultra-structural changes of liver were observed under transmission electron microscopy (TEM). Additionally, the mRNA expressions of PEPCK, G6Pase, insulin R and leptin R from rat livers were assayed by semi-quantitative RT-PCR. RESULTS: The levels of blood glucose, serum insulin, serum TG, ALT and AST increased significantly (P<0.01), serum TC elevated (P<0.05), and the levels of serum leptin decreased (P<0.01) in diabetic group compared to those in normal control group. Obvious liver fatty degeneration, piecemeal necrosis with accompanying inflammatory infiltration and fibrosis were found under LM. Hepatocytes pyknosis, lots of lipid deposits in cytoplasm of hepatocytes, proliferation of collagen in space of Disse were observed under TEM in diabetic group. The expression of insulin R and leptin R mRNA in liver from diabetic rats increased significantly (P<0.01) while the expression of PEPCK and G6Pase mRNA remained unchanged. CONCLUSION: Insulin resistance plays an important role in the pathogenesis of NAFLD. Low level of serum leptin, up-regulation of mRNA expression of insulin R and leptin R in liver caused by insulin resistance may be involved in this process.     

Effect of berberine on oxidative damage and the SIRT1/p53 pathway in liver tissues of NAFLD rats

AIM:To investigate the effect of berberine on oxidative damage and silent mating type information regulation 2 homolog 1 (SIRT1)/p53 pathway in the liver tissues of nonalcoholic fatty liver disease (NAFLD) rats and to explore the mechanism of berberine against NAFLD. METHODS:The male SD rats (n=24) were randomly divided into normal group, model group and berberine group (8 rats in each group). The rats in normal group was fed with normal diet, while the rats in model group and berberine group were fed with high-fat diet. The rats in berberine group was intragastrically administered with daily doses (100 mg/kg) of berberine for 16 weeks. The levels of liver total cholesterol (TC), triglyceride (TG), superoxide dismutase (SOD), malondialdehyde (MDA) and total anti-oxidant capatity (T-AOC) were measured. HE staining, oil red O straining and transmission electron microscopy were used to observe the histological changes of the livers. The protein levels of SIRT1, p53 and acetylated p53 (Ac-p53) were determined by Western blot. RESULTS:Compared with model group, the levels of liver TC, TG and MDA in berberine group were significantly reduced (P<0.05 or P<0.01), and the levels of SOD and T-AOC were significantly increased (P<0.01). The results of pathological observation showed that the lipid accumulation in the liver of berberine group was significantly attenuated. Compared with model group, the expression of SIRT1 was significantly increased and the expression of Ac-p53 was obviously reduced in berberine group (P<0.01). CONCLUSION:Berberine reduces hepatic steatosis and oxidative damage in NAFLD rats induce by high-fat diet, and this effect may be associated with regulation of the SIRT1/p53 signal pathway.     

Effect of bitter melon on liver fibrosis induced by carbon tetrachloride

AIM: To investigate the effects of bitter melon (BM) on liver fibrosis induced by CCl₄ in Wistar rats. METHODS: Healthy male Wistar rats were randomly divided into 4 groups (with 8 each): olive oil control group (group C), olive oil CCl₄ model group (group M), CCl₄+BM at low concentration (BM 100 g/kg, group BM-L), CCl₄+ BM at high concentration (BM 200 g/kg, group BM-H). All rats except those in group C were subcutaneously injected with CCl₄ twice a week for 8 weeks to induce liver fibrosis. After injection of CCl₄ for 8 weeks, all rats were sacrificed and the samples of blood and livers were collected. The weight ratio of liver to body was measured. The serum level of MDA and the activity of SOD were tested. The contents of total protein and albumin, the activity of GSH-Px, the content of hydroxyproline and the activity of monoamine oxidase in the liver homogenate were determined. Hepatic inflammation and collagen deposition were observed under microscope with Masson staining. RESULTS: In the rats treated with BM, the weight ratio of liver to body, the serum level of MDA, the content of hydroxyproline and the activity of monoamine oxidase in the liver homogenate were lower than those in group M (P<0.01). The serum activity of SOD, the contents of total protein and albumin, and the activity of GSH-Px in the liver homogenate were enhanced (P<0.01). The livers of the model rats had remarkable inflammatory necrosis, collagen accumulation and fibrosis. The rats in BM-treated group showed slighter hepatic injury and collagen deposition, and the liver functions were much better than those in the model group. High dose of BM showed more obvious liver-protective effects. CONCLUSION: BM attenuates liver fibrosis by its antioxidant effect and the mechanisms of reducing hydroxyproline content and monoamine oxidase activity.     

GLP-1 down-regulates mRNA expression of SOCS-3 and SREBP-1c in rats with nonalcoholic fatty liver disease

AIM: To investigate the effects of glucagon-like peptide-1(GLP-1) on mRNA expression of SOCS-3 and SREBP-1c in the rats with nonalcoholic fatty liver disease. METHODS: Male SD rats were randomly divided into normal control(NC) group, high fat(HF) group and HF+liraglutide(Lira) group. The rats in HF group and HF+Lira group were given high-fat diet for 16 weeks. After 12 weeks of high-fat diet feeding in HF+Lira group, Lira(600 μg·kg^-1·d^-1) was intraperitoneally injected for 4 weeks. At the end of the 16th week, the rats were killed. The pathological changes of the liver were observed under optical microscope. The serum levels of alanine aminotransferase(ALT), aspartate aminotransferase(AST), triglyceride(TG) and total cholesterol(TC) were detected by automatic biochemical analyzer. TG contents of liver were measured by GPO-PAP method. The fasting insulin(FINS) was determined by ELISA, and insulin resistance index was assessed by homeostasis mode assessment(HOMA-IR). The mRNA expression of SOCS-3 and SREBP-1c in the liver tissues was detected by RT-qPCR. RESULTS: Compared with NC group, HOMA-IR, TG of liver, and the serum levels of ALT, AST, TG, TC and FINS in HF group were obviously increased(P<0.01). Compared with HF group, HOMA-IR, TG of liver, and the serum levels of ALT, AST, TG, TC and FINS in HF+Lira group were all obviously decreased(P<0.05 or P<0.01). The mRNA expression of SOCS-3 and SREBP-1c in HF group was significantly higher than that in NC group(P<0.01). The mRNA expression of SOCSV3 and SREBP-1c in HF+Lira group was significantly decreased as compared with HF group(P<0.05). CONCLUSION: Liraglutide may improve the IR and reduce TG of liver through decreasing the mRNA expression of SOCS-3 and SREBP-1c, so as to play a therapeutic role in nonalcoholic fatty liver disease.     

Effects of liraglutide on adiponectin and insulin resistance in rats with non-alcoholic fatty liver disease

AIM：To investigate the effects of glucagon-like peptide 1 analog, liraglutide, on adiponectin and insulin resistance in the rats with diet-induced non-alcoholic fatty liver disease (NAFLD). METHODS：Male rats were randomly divided into 3 groups:normal diet (ND) group (n=10), high-fat diet (HFD) group (n=10), and HFD with intraperitoneal injection of liraglutide group (n=10, first 12 weeks with HFD, later 4 weeks with liraglutide). All treatments continued for 16 weeks, and then the rats were killed ethically and the blood samples and liver tissues were collected. The levels of alanine aminotransferase (ALT), fasting blood glucose (FBG), total cholesterol (TC) and triglyceride (TG) were detected by a biochemical automatic analyzer. The levels of free fatty acids (FFAs), fasting insulin (FINS) and adiponectin were measured by RIA and ELISA. RESULTS：Compared with HFD group, the body weight, liver index, homeostasis assessment-insulin resistance (HOMA-IR), the serum levels of TG, TC, ALT and FBG, and the liver levels of TG, TC and FFAs in the rats in liraglutide group were apparently lower, the degree of hepatic steatosis and inflammatory activity significantly decreased (P<0.05), and the level of adiponectin in the serum and liver homogenate increased ob-viously (P<0.05). The level of adiponectin in the liver homogenate was negatively correlated with the levels of FFAs in the liver homogenate. CONCLUSION:Liraglutide is beneficial for NAFLD rats to improve insulin resistance and reduce hepatic steatosis by increasing the level of adiponectin in the serum and liver tissues.     

Protective effects of aFGF compound solution on rat liver in hypothermic preservation

AIM: To investigate the protective effects of human acidic fibroblast growth factor (aFGF) on hypothermic preservation of rat liver. METHODS: Twenty-four Wistar rats were randomly divided into 2 groups (n=6): hypertonic citrate adenine (HCA) solution control group and experimental group (aFGF compound solution, containing 40 μg/L aFG_14-154 in HCA solution). The isolated livers were preserved in corresponding solution for 12 h or 24 h, and the content of malondialdehyde (MDA), the activity of alanine aminotransferase (ALT) and aspartate aminotransferase (AST), and the changes of liver weight in the 2 groups were analyzed. The histopathological changes of the livers were also examined. RESULTS: Compared with HCA control group, the levels of ALT, AST and MDA and the changes of liver weight were significantly decreased in experimental group (24 h), and the changes of liver histopathology were obviously alleviated in experiment group. CONCLUSION: aFGF can reduce rat hepatic injury. The protective effects of aFGF may be related to attenuating cell swelling and improving the capacity of anti-oxidative damage in the liver.     

Effect of diet with high fats and cholesterol on PPARα gene expression and body cholesterol level in mice

AIM:To investigate the effects of dietary fats and cholesterol on liver PPARα gene expression and body cholesterol (Chol) level in C57BL/6J mice. METHODS:The animals (n=75) were randomly divided into five groups and respectively received formula mash for 6 weeks. RESULTS:As compared to Chol diet, Chol+PUFA diet produced significantly higher liver cholesterol (P<0.01), serum total cholesterol (TC), focusing on HDL-C. While Chol+MUFA diet resulted in unchanged serum TC and lower liver cholesterol (P<0.01). Chol+SFA diet rsulted in higher liver cholesterol (P<0.01) and serum TC, focusing on LDL-C. Furthermore, Chol+PUFA diet increased the mRNA and protein content of PPARα (P<0.01) in liver, while Chol+MUFA and Chol+SFA diets decreased the mRNA content of PPARα significantly (P<0.01). CONCLUSIONS:These results indicated that addition of fats containing PUFA to diet high in cholesterol increased PPARα mRNA and protein expression, addition of fats containing MUFA or SFA to diet high in cholesterol decreased PPARα mRNA expression. The change of PPARα gene expression may further affect body cholesterol level.     

Effects of Aconiti tuber polysaccharides on hypercholesterolemia and hepatic cholesterol 7α-hydroxylase expression in rats

AIM: To investigate the effects of polysaccharides isolated from Aconiti tuber (Fuzi polysaccharides,FPS) on the prevention of hypercholesterolemia induced by high-cholesterol diet and the expression of hepatic cholesterol 7α-hydroxylase (cytochrome P450 7α-1, CYP7α-1) in rats.METHODS: Fifty male Wistar rats were randomly divided into 3 groups. The rats were fed with normal diet (control group), high-cholesterol diet (HC group) or high-cholesterol diet plus FPS (224, 448 or 896 mg·kg^-1·d^-1, FPS group) for 2 weeks. The serum lipid level, body weight, food-intake and fecal amount were measured at week 2. The pathological changes of the liver were observed with HE staining. The mRNA expression of hydroxy methylglutaryl coenzyme A (HMG-CoA) reductase and CYP7α-1, the protein level of CYP7α-1, and fecal bile acid were also detected at week 2.RESULTS: FPS significantly inhibited high-cholesterol diet-induced elevation of serum total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) (P<0.05). HE staining showed that FPS attenuated fatty degeneration in liver. Real-time PCR analysis showed that FPS significantly up-regulated the mRNA expression of CYP7α-1, but down-regulated the mRNA expression of HMG-CoA reductase (P<0.01). The protein level of CYP7α-1 was higher in FPS group than that in HC group (P<0.01). The level of fecal bile acid in HC-treated rats was higher than that in the control rats, and FPS stimulated the excretion of fecal bile acid (P<0.05).CONCLUSION: FPS significantly reduces serum cholesterol levels, which is associated with the up-regulation of hepatic CYP7α-1 expression and down-regulation of hepatic HMG-CoA reductase expression.     

Effect of salidroside on mitochondrial membrane potential during injury induced by hypoxia/hypoglycemia in cultured SH-SY5Y cells

AIM: To investigate the effects of salidroside on intracellular free calcium concentration [Ca²⁺]i, apoptosis, mitochondrial membrane potential (MMP) and activity during injury induced by hypoxia/hypoglycemia in cultured SH-SY5Y cells. METHODS: Mitochondrial activity was measured by methylthiazolyl tetrazolium test. MMP,[Ca²⁺]i and apoptosis were measured by flow cytometry. RESULTS: SH-SY5Y cells were cultured in a hypoxia/hypoglycemia condition for 2, 4, 6 and 12 h,[Ca²⁺]i and apoptosis rate significantly increased compared with control group (P<0.01). After hypoxia /hypoglycemia cultures, MMP and mitochondrial activity declined 29.17% (P<0.01) and 38.80% (P<0.01) at 2 h, 56.72% (P<0.01) and 63.58% (P<0.01) at 12 h, were lower than that in control group (P<0.01). Salidroside significantly decreased [Ca²⁺]i and apoptosis rate, and increased MMP and mitochondrial activity in hypoxia /hypoglycemia-treated SH-SY5Y cells. CONCLUSIONS: Salidroside might inhibit the decline in MMP and mitochondrial activity induced by hypoxia /hypoglycemia, and has an inhibitory effects on neuronal apoptosis. The mechanism might be related to inhibiting intracellular calcium overload.     

Effects of icariin on expression of transforming growth factor β1 and type Ⅳ collagen in diabetic rat testis

AIM: To determine the beneficial effects of icariin on streptozotocin (STZ)-induced diabetic testopathy in rats. METHODS: The diabetic animal model was induced in male Sprague-Dawley rats by an injection of streptozotocin (40 mg/kg, iv). The rats were randomly divided into 3 groups: control group, model group and icariin (80 mg/kg, ig) group. Twelve weeks after injected with streptozotocin, all rats were anaesthetized and killed to remove the testes from scrotum. Serum concentrations of glucose and testosterone, and the levels of succinate dehydrogenase (SDH), acid phosphatase (ACP), γ-glutamyl transpeptidase (γ-GT) and lactate dehydrogenase (LDH) in testes were measured. The morphology of the testicular tissues was observed under light microscope. Immunohistochemistry was employed to determine the protein levels of TGF-β₁ and type Ⅳ collagen. RESULTS: Compared with control group, the content of serum glucose increased while the serum level of testosterone and the activitiy of SDH, ACP, γ-GT and LDH in testis decreased in model group (P<0.01). The histopathological examination showed that the diameters of seminiferous tubules and various grades of spermatocytes in the testis were markedly decreased. Compared with control group, the expression of TGF-β₁ and collagen Ⅳ was significantly increased in model group. These alterations were significantly attenuated in icariin group (P<0.01). CONCLUSION: Icariin evidently relieves testicular damage in rats with diabetic testopathy by improving the secretion of testosterone and reducing the expression of TGF-β₁ and collagen Ⅳ at protein level.     

Extracellular cysteine/cystine redox potential affects mitochondrial function in NAFLD LO2 cells

AIM: To investigate the effects of extracellular cysteine/cystine redox potential (E_hCys/CySS) on the mitochondrial function of nonalcoholic fatty liver disease (NAFLD) hepatocytes. METHODS: LO2 cells were incubated with E_hCys/CySS of the oxidized (0 mV), the normal (-80 mV), or the reduced (-150 mV) status medium, then treated with oleic acid to establish NAFLD model in vitro. DCFH-DA and MitoSOX were used as the fluorescent probes for determining reactive oxygen species (ROS). Apocynin (NADPH oxidase inhibitor), MitoQ₁₀ (mitochondria-targeted antioxidant), rotenone (mitochondrial respiratory chain complex I inhibitor) and antimycin A (mitochondrial respiratory chain complex III inhibitor) were used to investigate the sources of ROS. RESULTS: An increase in ROS in LO2 cells by oleic acid was aggravated by the oxidized extracellular E_hCys/CySS (0 mV), which was removed by the reduced E_hCys/CySS (-150 mV). ROS generation by 0 mV was significantly eliminated by MitoQ₁₀. ROS levels were dependent on extracellular E_hCys/CySS in rotenone treated LO2 cells. A decline of mitochondrial membrane potential in the cells with NAFLD was aggravated by 0 mV and reversed by -150 mV. CONCLUSION: The oxidized extracellular E_hCys/CySS via inhibitiing of complex I intensifies ROS generation and reducing the mitochondrial membrane potential in the NAFLD hepatocytes, which were reversed by reduced E_hCys/CySS.     

Effect of betaine on liver injuries in aging db/db mice induced by lipids

AIM: To evaluate the effect of betaine on lipid metabolism disorder in inherited db/db mice with long-term nonalcoholic fatty liver disease (NAFLD).METHODS: Experimental NAFLD models were established by feeding the db/db mice with high-fat diet. Fifty 7-month-old db/db mice were randomly divided into 5 groups: the mice in low, medium and high dose groups were given betaine by intragastric administration at doses of 200 mg/kg, 400 mg/kg and 800 mg/kg for 6 weeks, respectively,while the mice in saline control group and positive drug group were given normal saline and positive control drug,respctively. All the animals were killed, and serum alanine aminotransferase (ALT), triglyceride (TG), total cholesterol (TC), low-density lipoprotein (LDL) and glucose tolerance were detected. The pathological changes of the liver tissues were also observed.RESULTS: Betaine significantly decreased the levels of ALT, TC and LDL (P<0.05 or P<0.01). The pathological changes of the liver tissues indicated that the content of lipid in the hepatocytes of betaine treatment groups was less than that in saline control group.CONCLUSION: Betaine significantly improves the lipid metabolism and the liver function in the aging db/db mice, and reduces the accumulation of lipid in the hepatocytes.     

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.     

Effects of thalidomide on the expression of NF-κB and TNF-α in experimental hepatic fibrotic rats

AIM: To study the effects of thalidomide on the expressions of nuclear factor κB (NF-κB) and tumor necrosis factor-α (TNF-α) in rat liver fibrosis.METHODS: The fibrosis of rat liver was induced by intraperitoneal injection of carbon tetrachloride thrice weekly.Meanwhile thalidomide (10 mg·kg^-1·d^-1 or 100 mg·kg^-1·d^-1) was given daily by the intragastric route for 8 weeks.Serum alanine aminotransferase (ALT),aspartate aminotransferase (AST),prealbumin (PA),hyaluronic acid (HA) and laminin (LN),and hydroxyproline (HYP) contents in the liver,NF-κB p65 and α-smooth muscle actin (α-SMA) protein in the liver,IκBα and TNF-α protein in cytoplasm and NF-κB p65 protein in nucleus and TNF-α mRNA levels in the liver were studied.RESULTS: Compared with the model group,the Knodell score,serum ALT,AST,HA,LN levels and HYP contents in liver,NF-κB p65 protein in nucleus and α-SMA protein in the liver,and TNF-α mRNA and protein in the liver of rats given high dose of thalidomide were decreased significantly (P<0.01).Meanwhile PA level and IκBα protein in cytoplasm were elevated significantly (P<0.01).CONCLUSION: Thalidomide exerts its effect on the down-regulation of NF-κB-induced TNF-α via inhibiting dissociation and degradation of IκB and prevents liver fibrosis in rats.     

Effect of urantide on liver function and histomorphology in atherosclerotic rats

AIM:To investigate the effect of urantide on the liver function and histomorphology in the rats with atherosclerosis (AS).METHODS:The AS Wistar rat model was induced by intraperitoneal injection of vitamin D₃ (VD₃) and feeding with high-fat diet. The rats were randomly divided into normal control group, AS model group, positive medicine group and urantide group. The liver function indexes of the rats were measured by biochemical test, and the pathological changes of the aorta and liver of the rats were observed by hematoxylin-eosin (HE) staining. The mRNA expression of urotensin Ⅱ (UⅡ) and GPR14 at mRNA and protein levels in rat livers was determined by RT-qPCR and Western blot. RESULTS:The levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), γ-glutamyltransferase (γ-GT), lactate dehydrogenase (LDH), total bilirubin (TBIL), indirect bilirubin (IBIL) and alkaline phosphatase (ALP) in AS model group were significantly increased compared with normal control group (P<0.05). The above indexes in urantide group were remarkably decreased compared with AS model group (P<0.05). No change of the levels of direct bilirubin (DBIL), total protein (TP), globulin (GLB) and albumin (ALB) in each group was observed. Urantide postponed hepatocyte fatty degeneration and repaired hepatocyte injury in the AS rats. Compared with normal control group, the mRNA and protein levels of UⅡ and GPR14 in the liver were significantly increased in AS model group (P<0.05). With the prolongation of dosing time, the mRNA and protein levels of UⅡ and GPR14 in the liver were significantly decreased in urantide group compared with AS model group (P<0.05). CONCLUSION:Urantide significantly attenuates the liver damage caused by liver fatty degeneration in AS rats.     

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.     

Mechanism of Fuzilizhong decoction alleviating inflammatory damage of rats with non-alcoholic fatty liver disease

AIM To observe the effect of Fuzilizhong decoction on the inflammatory damage of non-alcoholic fatty liver disease （NAFLD） rats and to explore its mechanism. METHODS SPF male SD rats were randomly divided into 6 groups： control group, model group, high dose （20 mg·kg^-1·d^-1）, middle dose （10 mg·kg^-1·d^-1）, low dose （5 mg·kg^-1·d^-1） Fuzilizhong decoction group and Yishanfu （30 mg·kg^-1·d^-1）group, 8 rats in each group. A NAFLD rat modelwas established by intragastric administration of fat emulsion for 4 weeks. Then the drug was given for 4 weeks in each treatment group. HE staining was performed to observe the histopathological changes of the rat liver.The serum levels of interleukin-2（IL-2）, IL-6 and tumor necrosis factor-α（TNF-α） were measured by ELISA. The expression of toll like receptor 4（TLR4） and NF-κB p65 in liver tissues at mRNA and protein levels was determined by RT-qPCR and Western bolt,respectively. RESULTS Compared with control group, the inflammatory damage of liver tissue was more serious, the serum levels of IL-2, IL-6 and TNF-α, the mRNA expression TLR4 and NF-κB p65 in liver tissues were significantly increased in model group（P<0.05）. However, compared with model group, the liver pathological changes in each treatment group were significantly relieved, the serum levels of IL-2, IL-6 and TNF-α, the mRNA expression of TLR4 and NF-κB p65 in liver tissues were significantly reduced（P<0.05）.In addition, the changes of TLR4 and p-NF-κB p65 protein levels in liver tissue were consistent with the changes of TLR4 and NF-κB p65 mRNA. CONCLUSION Fuzilizhong decoction attenuates the inflammatory damages of NAFLD in rats by inhibiting TLR4/NF-κB p65 signaling pathway.     

Changes of mitochondrial peripheral-type benzodiazepine receptor during rat live regeneration

AIM: To investigate the expression profile of peripheral-type benzodiazepine receptor (PBR) involved in mitochondrial permeability transition (PT) regulation, and to observe the binding dynamic of the mitochondrial PBR with specificity ligand during rat live regeneration. METHODS: Liver regeneration model was produced by 70% partial hepatectomy (PH) performed in male SD rats. The animals of sham groups underwent the same surgical operations as PH groups did, but the liver lobes were not resected. The animals in the PH groups and corresponding sham groups were sacrificed at 3, 6, 12, 24, 48, 72, 120 and 168 hours after the operation. The livers were removed, weighted and processed for isolation of mitochondria. Semi-quantitative RT-PCR was performed to examine the expression level of PBR in 70% hepatectomized rat livers during the whole regeneration process and compared to that in the sham and normal groups. Compared with healthy rats, the kinetic parameters of PBR was evaluated by using a specific radioligand ［3H］-PK11195. RESULTS: Compared with healthy rats, the expression of PBR was unchanged. Meanwhile, the results obtained in the present experiments by scatchard analysis, Bmax of PK11195 for PBR significantly decreased, returned to normal level in 168 h after PH. Kd of PK11195 for PBR significantly decreased at 72 h and 168 h after PH of rat liver regeneration (P<0.01). CONCLUSION: The mRNA expression and evaluation of kinetic parameters of PBR may be related to the time-phase change of mitochondrial PT during rat liver regeneration after partial hepatectomy.