AIM: To determine whether high-protein, high-fat, and low-carbohydrate diets can cause lesions in rat livers.METHODS: We randomly divided 20 female Wistar rats into a control diet group and an experimental diet group....AIM: To determine whether high-protein, high-fat, and low-carbohydrate diets can cause lesions in rat livers.METHODS: We randomly divided 20 female Wistar rats into a control diet group and an experimental diet group. Animals in the control group received an AIN-93 M diet, and animals in the experimental group received an Atkins-based diet(59.46% protein, 31.77% fat, and 8.77% carbohydrate). After 8 wk, the rats were anesthetized and exsanguinated for transaminases analysis, and their livers were removed for flow cytometry, immunohistochemistry, and light microscopy studies. We expressed the data as mean ± standard deviation(sd) assuming unpaired and parametric data; we analyzed differences using the student's t-test. statistical significance was set at P < 0.05.RESULTS: We found that plasma alanine aminotransferase and aspartate aminotransferase levels were significantly higher in the experimental group than in the control group. According to flow cytometry, the percentages of nonviable cells were 11.67% ± 1.12% for early apoptosis, 12.07% ± 1.11% for late apoptosis, and 7.11% ± 0.44% for non-apoptotic death in the experimental diet group and 3.73% ± 0.50% for early apoptosis, 5.67% ± 0.72% for late apoptosis, and 3.82% ± 0.28% for non-apoptotic death in the control diet group. The mean percentage of early apoptosis was higher in the experimental diet group than in the control diet group. Immunohistochemistry for autophagy was negative in both groups. sinusoidal dilation around the central vein and small hepatocytes was only observed in the experimental diet group, and fibrosis was not identified by hematoxylin-eosin or Trichrome Masson staining in either group.CONCLUSION: Eight weeks of an experimental diet resulted in cellular and histopathological lesions in rat livers. Apoptosis was our principal finding; elevated plasma transaminases demonstrate hepatic lesions.展开更多
AIM To elucidate how high diet-induced endoplasmic reticulum-stress upregulates thioredoxin interacting protein expression in Müller cells leading to retinal inflammation. METHODS Male C57Bl/J mice were fed eithe...AIM To elucidate how high diet-induced endoplasmic reticulum-stress upregulates thioredoxin interacting protein expression in Müller cells leading to retinal inflammation. METHODS Male C57Bl/J mice were fed either normal diet or 60% high fat diet for 4-8 wk. During the 4 wk study, mice received phenyl-butyric acid(PBA); endoplasmic reticulum-stress inhibitor; for 2 wk. Insulin resistance was assessed by oral glucose tolerance. Effects of palmitate-bovine serum albumin(BSA)(400 μmol/L) were examined in retinal Müller glial cell line and primary Müller cells isolated from wild type and thioredoxin interacting protein knock-out mice. Expression of thioredoxin interacting protein, endoplasmic reticulum-stress markers, mi R-17-5p m RNA, as well as nucleotide-binding oligomerization domain-like receptor protein(NLRP3) and IL1β protein was determined.RESULTS High fat diet for 8 wk induced obesity and insulin resistance evident by increases in body weight and impaired glucose tolerance. By performing quantitative real-time polymerase chain reaction, we found that high fat diet triggered the expression of retinal endoplasmic reticulum-stress markers(P < 0.05). These effects were associated with increased thioredoxin interacting protein and decreased mi R-17-5p expression, whichwere restored by inhibiting endoplasmic reticulumstress with PBA(P < 0.05). In vitro, palmitate-BSA triggered endoplasmic reticulum-stress markers, which was accompanied with reduced mi R-17-5p and induced thioredoxin interacting protein m RNA in retinal Müller glial cell line(P < 0.05). Palmitate upregulated NLRP3 and IL1β expression in primary Müller cells isolated from wild type. However, using primary Müller cells isolated from thioredoxin interacting protein knock-out mice abolished palmitate-mediated increase in NLRP3 and IL1β.CONCLUSION Our work suggests that targeting endoplasmic reticulumstress or thioredoxin interacting protein are potential therapeutic strategies for early intervention of obesityinduced retinal inflammation.展开更多
AIM: To investigate the effect of Platycodon grandi- florum extract (PGE) on lipid metabolism and FABP mRNA expression in subcutaneous adipose tissue of high fat diet-induced obese rats. METHODS: PGE was treated to in...AIM: To investigate the effect of Platycodon grandi- florum extract (PGE) on lipid metabolism and FABP mRNA expression in subcutaneous adipose tissue of high fat diet-induced obese rats. METHODS: PGE was treated to investigate the inhibitory effect on the pre-adipocyte 3T3-L1 differentiation and pancreatic lipase activity. Male Sprague-Dawley rats with an average weight of 439.03 ± 7.61 g were divided into four groups: the control groups that fed an experimental diet alone (C and H group) and PGE treatment groups that administered PGE along with a control diet or HFD at a concentration of 150 mg/kg body weight (C + PGE and H + PGE group, respectively) for 7 wk. Plasma total cholesterol (TC) and triglycerol (TG) concentrations were measured from the tail vein of rats. Adipocyte cell area was measured from subcutaneous adipose tissue and the fatty acid binding protein (FABP) mRNA expression was analyzed by northern blot analysis. RESULTS: PGE treatment inhibited 3T3-L1 pre-adipocyte differentiation and fat accumulation, and also decreased pancreatic lipase activity. In this experiment, PGE signifi cantly reduced plasma TC and TG concentrations as well as body weight and subcutaneous adipose tissue weight. PGE also significantly decreased the size of subcutaneous adipocytes. Furthermore, it significantly repressed the up-regulation of FABP mRNA expression induced by a high-fat feeding in subcutaneous adipose tissue. CONCLUSION: PGE has a plasma lipid lowering-effect and anti-obesity effect in obese rats fed a high fat diet.From these results, we can suggest the possibility that PGE can be used as a food ingredient or drug component to therapeutically control obesity.展开更多
Background: High protein (HP) diets are increasingly being recommended as one of the management strategies for weight control in overweight and obese individuals. The health benefits of high protein diets are well-est...Background: High protein (HP) diets are increasingly being recommended as one of the management strategies for weight control in overweight and obese individuals. The health benefits of high protein diets are well-established, but the mechanisms of action on body systems responsible for the changes in body weight and glycaemic control are not well-clear. Objective: The present study aimed to examine the effect of HP diets on the kidney functions of diabetic obese albino rats. Material and Methods: Eighty male adult male albino rats were used in this study. The animals were divided into eight equal groups (10 rats for each). Type 2 DM and obesity were induced. At the end of the 12 weeks, samples were collected for biochemical analysis. Results: The high protein diet led to significant decrease in BW, FI, BG, TC, LDL, TG, Lactate dehydrogenase, albumin, urine pH and urine citrate;while serum insulin, HDL, urea, creatinine, total protein, urine volume and urinary excretion of Ca were significantly higher in high protein diet groups. Conclusion: A high protein intake in diabetic obese albino rats for 12 weeks led to changes in the serum and urine levels of markers of renal function which indicated abnormalities in the functions of the kidney.展开更多
Objective: Idiopathic reactive hypoglycemia is defined as early postprandial hypoglycemia occurring on ingestion of high carbohydrate containing meal. Remission ensues with high protein low carbohydrate diet. This stu...Objective: Idiopathic reactive hypoglycemia is defined as early postprandial hypoglycemia occurring on ingestion of high carbohydrate containing meal. Remission ensues with high protein low carbohydrate diet. This study assessed roles of insulin and glucagon in its onset and remission. Methods: Plasma glucose, insulin and glucagon were determined after an overnight fast and repeatedly until 180 minutes on ingestion of 3 meals;100 g glucose;100 g pure protein liquid and mixture of 50 g each at 14 days’ interval. Five adults with IRH and 6 age matched healthy volunteers participated. Results: In IRH, glucose ingestion induced prompt rise in glucose (5.1 ± 0.8 to10.5 ± 1.2 mM/L) followed later by hypoglycemia (2.6 ± 0.4 mM/L). Insulin rose from 7 ± 2 to 90 ± 18 mU/L. Glucagon rose initially (10% ± 2%) from elevated basal concentration (373 ± 57 mU/L) followed by later decline (-43% ± 12%). On protein ingestion, glucose declined followed by a restoration to basal level while both insulin and glucagon rose (28 ± 6 mU/L;148% ± 38%, p < 0.01). However, insulin response was lower and glucagon rise was greater when compared to responses on glucose ingestion (p < 0.01). With mixed meal, glucose (8.2 ± 0.6 mM/L), insulin (65 ± 12 mU/L) and glucagon (48% ± 7%) responses were lesser than rises following glucose ingestion (p < 0.05) and hypoglycemia did not occur. Conclusion: In IRH, initial hyperglycemia on glucose ingestion may be exacerbated by paradoxical glucagon rise and hypoglycemia may be induced by increased insulin and declining glucagon responses. Resolution of hypoglycemia with high protein low carbohydrate diet may be attributed to blunting of insulin response and concurrent glucagon rise.展开更多
AIM To determine the effect of tempol in normal rats fed high salt on arterial pressure and the balance between antagonist components of the renal renin-angiotensin system.METHODS Sprague-Dawley rats were fed with 8% ...AIM To determine the effect of tempol in normal rats fed high salt on arterial pressure and the balance between antagonist components of the renal renin-angiotensin system.METHODS Sprague-Dawley rats were fed with 8% NaCl high-salt （HS） or 0.4% NaCl （normal-salt, NS） diet for 3 wk, with or without tempol （T） （1 mmol/L, administered in drinking water）. Mean arterial pressure （MAP）, glomerular fltration rate （GFR）, and urinary sodium excretion （UVNa） were measured. We evaluated angiotensin Ⅱ （Ang Ⅱ）, angiotensin 1-7 （Ang 1-7）, angiotensin converting enzyme 2 （ACE2）, mas receptor （MasR）, angiotensin type 1 receptor （AT1R） and angiotensin type 2 receptor （AT2R） in renal tissues by immunohistochemistry.RESULTSThe intake of high sodium produced a slight but signifcant increase in MAP and differentially regulated components of the renal renin-angiotensin system （RAS）. This included an increase in Ang Ⅱ and AT1R, and decrease in ACE-2 staining intensity using immunohistochemistry. Antioxidant supplementation with tempol increased natriuresis and GFR, prevented changes in blood pressure and reversed the imbalance of renal RAS components. This includes a decrease in Ang Ⅱ and AT1R, as increase in AT2, ACE2, Ang （1-7） and MasR staining intensity using immunohistochemistry. In addition, the natriuretic effects of tempol were observed in NS-T group, which showed an increased staining intensity of AT2, ACE2, Ang （1-7） and MasR.CONCLUSION These findings suggest that a high salt diet leads to changes in the homeostasis and balance between opposing components of the renal RAS in hypertension to favour an increase in Ang Ⅱ. Chronic antioxidant supplementation can modulate the balance between the natriuretic and antinatriuretic components of the renal RAS.展开更多
Objective:To investigate the effects of Clean-DM1(C-DM1),a polyherbal formulation of Radix Scrophulariae,Radix Astragali,Rhizoma Atractylodis,and Radix Salviae Miltiorrhizae,on high-fat diet(HFD)-induced diabetes mice...Objective:To investigate the effects of Clean-DM1(C-DM1),a polyherbal formulation of Radix Scrophulariae,Radix Astragali,Rhizoma Atractylodis,and Radix Salviae Miltiorrhizae,on high-fat diet(HFD)-induced diabetes mice.Methods:The information about active components of C-DM1 extract and molecular mechanism was obtained from network pharmacology analysis.Main compounds of C-DM1 extract by high performance liquid chromatography-mass spectrometry(HPLC-MS)analysis were conducted for quality control.For in vivo study,mice were induced diabetes by HFD for 12 weeks.The mice in the normal group(Nor)were maintained with a regular diet and treated with saline by gavage.The HFD model mice were randomly divided into 3 groups,including a HFD diabetic model group,a C-DM1 extract-administered group(C-DM1,500 mg/kg),and metformin-administered groups(Met,500 mg/kg),8 mice in each group.Food intake,body weight(BW),and fasting blood glucose(FBG)levels were recorded weekly for 4 weeks.After 4 weeks of treatment,alanine aminotransferase(ALT),aspartate aminotransferase(AST),blood glucose,low-density lipoprotein cholesterol(LDL-C)were determined using an automated clinical chemistry analyzer,and homeostatic model for assessing insulin resistance(HOMA-IR)levels and oral glucose tolerance test(OGTT)were detected.The histopathological changes of liver and pancreatic tissues were observed by hematoxylin-eosin staining.Insulin receptor substrate(IRS)/phosphatidylinositol 3 kinase(PI3K)/protein kinase B(AKT)and adenosine 5'-monophosphate-activated protein kinase(AMPK)expressions in liver and pancreas tissues were detected by Western blot analysis.Results:HPLC-MS identified dihydroisotanshinone,dihydroisotanshinone I,cryptotanshinone,harpagoside,and atractyloside A in C-DM1 extract.The administration of C-DM1 extract significantly decreased body weight,calorie intake,and the levels of blood glucose and insulin in the diabetic mice(P<0.05 or P<0.01).The C-DM1 extract administration improved the impaired glucose tolerance and insulin resistance in the diabetic mice and significantly decreased the levels of LDL-C,ALT and AST(P<0.01).The C-DM1 extract inhibited the histopathological changes of fatty liver and hyperplasia of pancreatic islets in the diabetic mice.The C-DM1 extract significantly increased the phosphorylation of IRS,AKT,and AMPK and the expression of PI3K in pancreas and liver tissues(P<0.05 or P<0.01),which was consistent with the analysis results of network pharmacology.Conclusion:C-DM1 extract improved diabetes symptoms in longterm HFD-induced mice by regulation of IRS/PI3K/AKT and AMPK expressions in pancreas and liver tissues,suggesting that C-DM1 formulation may help prevent the progression of T2DM.展开更多
AIM To study the effects of different diets on intestinal microbiota and nonalcoholic fatty liver disease(NAFLD) development at the same caloric intake.METHODS Thirty male Sprague-Dawley rats were randomized into five...AIM To study the effects of different diets on intestinal microbiota and nonalcoholic fatty liver disease(NAFLD) development at the same caloric intake.METHODS Thirty male Sprague-Dawley rats were randomized into five groups(six rats each). The control diet(CON) group and free high-fat diet(FFAT) group were allowed ad libitum access to a normal chow diet and a highfat diet, respectively. The restrictive high-fat diet(RFAT) group, restrictive high-sugar diet(RSUG) group, and high-protein diet(PRO) group were fed a highfat diet, a high-sugar diet, and a high-protein diet, respectively, in an isocaloric way. All rats were killed at 12 wk. Body weight, visceral fat index(visceral fat/body weight), liver index(liver/body weight), insulin resistance, portal lipopolysaccharide(LPS), serum alanine aminotransferase(ALT), serum aspartate aminotransferase(AST), and liver triglycerides were measured. The intestinal microbiota in the different groups of rats was sequenced using high-throughput sequencing technology.RESULTS The FFAT group had higher body weight, visceral fat index, liver index, peripheral insulin resistance, portal LPS, serum ALT, serum AST, and liver triglycerides compared with all other groups(P < 0.05). Taking the same calories, the RFAT and RSUG groups demonstrated increased body weight, visceral fat index, peripheral insulin resistance and liver triglycerides compared with the PRO group(P < 0.05). The RFAT group also showed increased portal LPS compared with the PRO group(P < 0.05). Unweighted Uni Frac principal coordinates analysis of the sequencing data revealed that the intestinal microbiota structures of the CON, FFAT, RSUG and PRO groups were roughly separated away from each other. Taxon-based analysis showed that, compared with the CON group, the FFAT group had an increased abundance of Firmicutes, Roseburia and Oscillospira bacteria, a higher ratio of Firmicutes to Bacteroidetes, and a decreased abundance of Bacteroidetes, Bacteroides and Parabacteroides bacteria(P < 0.05). The RFAT group showed an increased abundance of Firmicutes and decreased abundance of Parabacteroides bacteria(P < 0.05). The RSUG group showed an increased abundance of Bacteroidetes and Sutterella bacteria, higher ratio of Bacteroidetes to Firmicutes, and a decreased abundance of Firmicutes(P < 0.05). The PRO group showed an increased abundance of Bacteroidetes, Prevotella, Oscillospira and Sutterella bacteria, and a decreased abundance of Firmicutes(P < 0.05). Compared with the FFAT group, the RFAT group had an increased abundance of Bacteroidetes, higher ratio of Bacteroidetes to Firmicutes, and decreased abundance of Firmicutes and Oscillospira bacteria(P < 0.05).CONCLUSION Compared with the high-protein diet, the NAFLDinducing effects of high-fat and high-sugar diets are independent from calories, and may be associated with changed intestinal microbiota.展开更多
文摘AIM: To determine whether high-protein, high-fat, and low-carbohydrate diets can cause lesions in rat livers.METHODS: We randomly divided 20 female Wistar rats into a control diet group and an experimental diet group. Animals in the control group received an AIN-93 M diet, and animals in the experimental group received an Atkins-based diet(59.46% protein, 31.77% fat, and 8.77% carbohydrate). After 8 wk, the rats were anesthetized and exsanguinated for transaminases analysis, and their livers were removed for flow cytometry, immunohistochemistry, and light microscopy studies. We expressed the data as mean ± standard deviation(sd) assuming unpaired and parametric data; we analyzed differences using the student's t-test. statistical significance was set at P < 0.05.RESULTS: We found that plasma alanine aminotransferase and aspartate aminotransferase levels were significantly higher in the experimental group than in the control group. According to flow cytometry, the percentages of nonviable cells were 11.67% ± 1.12% for early apoptosis, 12.07% ± 1.11% for late apoptosis, and 7.11% ± 0.44% for non-apoptotic death in the experimental diet group and 3.73% ± 0.50% for early apoptosis, 5.67% ± 0.72% for late apoptosis, and 3.82% ± 0.28% for non-apoptotic death in the control diet group. The mean percentage of early apoptosis was higher in the experimental diet group than in the control diet group. Immunohistochemistry for autophagy was negative in both groups. sinusoidal dilation around the central vein and small hepatocytes was only observed in the experimental diet group, and fibrosis was not identified by hematoxylin-eosin or Trichrome Masson staining in either group.CONCLUSION: Eight weeks of an experimental diet resulted in cellular and histopathological lesions in rat livers. Apoptosis was our principal finding; elevated plasma transaminases demonstrate hepatic lesions.
文摘AIM To elucidate how high diet-induced endoplasmic reticulum-stress upregulates thioredoxin interacting protein expression in Müller cells leading to retinal inflammation. METHODS Male C57Bl/J mice were fed either normal diet or 60% high fat diet for 4-8 wk. During the 4 wk study, mice received phenyl-butyric acid(PBA); endoplasmic reticulum-stress inhibitor; for 2 wk. Insulin resistance was assessed by oral glucose tolerance. Effects of palmitate-bovine serum albumin(BSA)(400 μmol/L) were examined in retinal Müller glial cell line and primary Müller cells isolated from wild type and thioredoxin interacting protein knock-out mice. Expression of thioredoxin interacting protein, endoplasmic reticulum-stress markers, mi R-17-5p m RNA, as well as nucleotide-binding oligomerization domain-like receptor protein(NLRP3) and IL1β protein was determined.RESULTS High fat diet for 8 wk induced obesity and insulin resistance evident by increases in body weight and impaired glucose tolerance. By performing quantitative real-time polymerase chain reaction, we found that high fat diet triggered the expression of retinal endoplasmic reticulum-stress markers(P < 0.05). These effects were associated with increased thioredoxin interacting protein and decreased mi R-17-5p expression, whichwere restored by inhibiting endoplasmic reticulumstress with PBA(P < 0.05). In vitro, palmitate-BSA triggered endoplasmic reticulum-stress markers, which was accompanied with reduced mi R-17-5p and induced thioredoxin interacting protein m RNA in retinal Müller glial cell line(P < 0.05). Palmitate upregulated NLRP3 and IL1β expression in primary Müller cells isolated from wild type. However, using primary Müller cells isolated from thioredoxin interacting protein knock-out mice abolished palmitate-mediated increase in NLRP3 and IL1β.CONCLUSION Our work suggests that targeting endoplasmic reticulumstress or thioredoxin interacting protein are potential therapeutic strategies for early intervention of obesityinduced retinal inflammation.
文摘AIM: To investigate the effect of Platycodon grandi- florum extract (PGE) on lipid metabolism and FABP mRNA expression in subcutaneous adipose tissue of high fat diet-induced obese rats. METHODS: PGE was treated to investigate the inhibitory effect on the pre-adipocyte 3T3-L1 differentiation and pancreatic lipase activity. Male Sprague-Dawley rats with an average weight of 439.03 ± 7.61 g were divided into four groups: the control groups that fed an experimental diet alone (C and H group) and PGE treatment groups that administered PGE along with a control diet or HFD at a concentration of 150 mg/kg body weight (C + PGE and H + PGE group, respectively) for 7 wk. Plasma total cholesterol (TC) and triglycerol (TG) concentrations were measured from the tail vein of rats. Adipocyte cell area was measured from subcutaneous adipose tissue and the fatty acid binding protein (FABP) mRNA expression was analyzed by northern blot analysis. RESULTS: PGE treatment inhibited 3T3-L1 pre-adipocyte differentiation and fat accumulation, and also decreased pancreatic lipase activity. In this experiment, PGE signifi cantly reduced plasma TC and TG concentrations as well as body weight and subcutaneous adipose tissue weight. PGE also significantly decreased the size of subcutaneous adipocytes. Furthermore, it significantly repressed the up-regulation of FABP mRNA expression induced by a high-fat feeding in subcutaneous adipose tissue. CONCLUSION: PGE has a plasma lipid lowering-effect and anti-obesity effect in obese rats fed a high fat diet.From these results, we can suggest the possibility that PGE can be used as a food ingredient or drug component to therapeutically control obesity.
文摘Background: High protein (HP) diets are increasingly being recommended as one of the management strategies for weight control in overweight and obese individuals. The health benefits of high protein diets are well-established, but the mechanisms of action on body systems responsible for the changes in body weight and glycaemic control are not well-clear. Objective: The present study aimed to examine the effect of HP diets on the kidney functions of diabetic obese albino rats. Material and Methods: Eighty male adult male albino rats were used in this study. The animals were divided into eight equal groups (10 rats for each). Type 2 DM and obesity were induced. At the end of the 12 weeks, samples were collected for biochemical analysis. Results: The high protein diet led to significant decrease in BW, FI, BG, TC, LDL, TG, Lactate dehydrogenase, albumin, urine pH and urine citrate;while serum insulin, HDL, urea, creatinine, total protein, urine volume and urinary excretion of Ca were significantly higher in high protein diet groups. Conclusion: A high protein intake in diabetic obese albino rats for 12 weeks led to changes in the serum and urine levels of markers of renal function which indicated abnormalities in the functions of the kidney.
文摘Objective: Idiopathic reactive hypoglycemia is defined as early postprandial hypoglycemia occurring on ingestion of high carbohydrate containing meal. Remission ensues with high protein low carbohydrate diet. This study assessed roles of insulin and glucagon in its onset and remission. Methods: Plasma glucose, insulin and glucagon were determined after an overnight fast and repeatedly until 180 minutes on ingestion of 3 meals;100 g glucose;100 g pure protein liquid and mixture of 50 g each at 14 days’ interval. Five adults with IRH and 6 age matched healthy volunteers participated. Results: In IRH, glucose ingestion induced prompt rise in glucose (5.1 ± 0.8 to10.5 ± 1.2 mM/L) followed later by hypoglycemia (2.6 ± 0.4 mM/L). Insulin rose from 7 ± 2 to 90 ± 18 mU/L. Glucagon rose initially (10% ± 2%) from elevated basal concentration (373 ± 57 mU/L) followed by later decline (-43% ± 12%). On protein ingestion, glucose declined followed by a restoration to basal level while both insulin and glucagon rose (28 ± 6 mU/L;148% ± 38%, p < 0.01). However, insulin response was lower and glucagon rise was greater when compared to responses on glucose ingestion (p < 0.01). With mixed meal, glucose (8.2 ± 0.6 mM/L), insulin (65 ± 12 mU/L) and glucagon (48% ± 7%) responses were lesser than rises following glucose ingestion (p < 0.05) and hypoglycemia did not occur. Conclusion: In IRH, initial hyperglycemia on glucose ingestion may be exacerbated by paradoxical glucagon rise and hypoglycemia may be induced by increased insulin and declining glucagon responses. Resolution of hypoglycemia with high protein low carbohydrate diet may be attributed to blunting of insulin response and concurrent glucagon rise.
基金Supported by A grant from the Universidad de Buenos Aires(UBACYT 20020130200105BA)
文摘AIM To determine the effect of tempol in normal rats fed high salt on arterial pressure and the balance between antagonist components of the renal renin-angiotensin system.METHODS Sprague-Dawley rats were fed with 8% NaCl high-salt （HS） or 0.4% NaCl （normal-salt, NS） diet for 3 wk, with or without tempol （T） （1 mmol/L, administered in drinking water）. Mean arterial pressure （MAP）, glomerular fltration rate （GFR）, and urinary sodium excretion （UVNa） were measured. We evaluated angiotensin Ⅱ （Ang Ⅱ）, angiotensin 1-7 （Ang 1-7）, angiotensin converting enzyme 2 （ACE2）, mas receptor （MasR）, angiotensin type 1 receptor （AT1R） and angiotensin type 2 receptor （AT2R） in renal tissues by immunohistochemistry.RESULTSThe intake of high sodium produced a slight but signifcant increase in MAP and differentially regulated components of the renal renin-angiotensin system （RAS）. This included an increase in Ang Ⅱ and AT1R, and decrease in ACE-2 staining intensity using immunohistochemistry. Antioxidant supplementation with tempol increased natriuresis and GFR, prevented changes in blood pressure and reversed the imbalance of renal RAS components. This includes a decrease in Ang Ⅱ and AT1R, as increase in AT2, ACE2, Ang （1-7） and MasR staining intensity using immunohistochemistry. In addition, the natriuretic effects of tempol were observed in NS-T group, which showed an increased staining intensity of AT2, ACE2, Ang （1-7） and MasR.CONCLUSION These findings suggest that a high salt diet leads to changes in the homeostasis and balance between opposing components of the renal RAS in hypertension to favour an increase in Ang Ⅱ. Chronic antioxidant supplementation can modulate the balance between the natriuretic and antinatriuretic components of the renal RAS.
基金Supported by Korea Health Technology R&D Project through the Korea Health Industry Development Institute (KHIDI),the Ministry of Health&Welfare,Republic of Korea (No. HF20C0121)Shanxi Key Laboratory of Tradition Herbal Medicines Processing (No. 20210901)the Innovation Team of Shanxi University of Chinese Medicine (No. 2022TD1014)
文摘Objective:To investigate the effects of Clean-DM1(C-DM1),a polyherbal formulation of Radix Scrophulariae,Radix Astragali,Rhizoma Atractylodis,and Radix Salviae Miltiorrhizae,on high-fat diet(HFD)-induced diabetes mice.Methods:The information about active components of C-DM1 extract and molecular mechanism was obtained from network pharmacology analysis.Main compounds of C-DM1 extract by high performance liquid chromatography-mass spectrometry(HPLC-MS)analysis were conducted for quality control.For in vivo study,mice were induced diabetes by HFD for 12 weeks.The mice in the normal group(Nor)were maintained with a regular diet and treated with saline by gavage.The HFD model mice were randomly divided into 3 groups,including a HFD diabetic model group,a C-DM1 extract-administered group(C-DM1,500 mg/kg),and metformin-administered groups(Met,500 mg/kg),8 mice in each group.Food intake,body weight(BW),and fasting blood glucose(FBG)levels were recorded weekly for 4 weeks.After 4 weeks of treatment,alanine aminotransferase(ALT),aspartate aminotransferase(AST),blood glucose,low-density lipoprotein cholesterol(LDL-C)were determined using an automated clinical chemistry analyzer,and homeostatic model for assessing insulin resistance(HOMA-IR)levels and oral glucose tolerance test(OGTT)were detected.The histopathological changes of liver and pancreatic tissues were observed by hematoxylin-eosin staining.Insulin receptor substrate(IRS)/phosphatidylinositol 3 kinase(PI3K)/protein kinase B(AKT)and adenosine 5'-monophosphate-activated protein kinase(AMPK)expressions in liver and pancreas tissues were detected by Western blot analysis.Results:HPLC-MS identified dihydroisotanshinone,dihydroisotanshinone I,cryptotanshinone,harpagoside,and atractyloside A in C-DM1 extract.The administration of C-DM1 extract significantly decreased body weight,calorie intake,and the levels of blood glucose and insulin in the diabetic mice(P<0.05 or P<0.01).The C-DM1 extract administration improved the impaired glucose tolerance and insulin resistance in the diabetic mice and significantly decreased the levels of LDL-C,ALT and AST(P<0.01).The C-DM1 extract inhibited the histopathological changes of fatty liver and hyperplasia of pancreatic islets in the diabetic mice.The C-DM1 extract significantly increased the phosphorylation of IRS,AKT,and AMPK and the expression of PI3K in pancreas and liver tissues(P<0.05 or P<0.01),which was consistent with the analysis results of network pharmacology.Conclusion:C-DM1 extract improved diabetes symptoms in longterm HFD-induced mice by regulation of IRS/PI3K/AKT and AMPK expressions in pancreas and liver tissues,suggesting that C-DM1 formulation may help prevent the progression of T2DM.
基金Supported by National Natural Science Foundation of China,No.81300270
文摘AIM To study the effects of different diets on intestinal microbiota and nonalcoholic fatty liver disease(NAFLD) development at the same caloric intake.METHODS Thirty male Sprague-Dawley rats were randomized into five groups(six rats each). The control diet(CON) group and free high-fat diet(FFAT) group were allowed ad libitum access to a normal chow diet and a highfat diet, respectively. The restrictive high-fat diet(RFAT) group, restrictive high-sugar diet(RSUG) group, and high-protein diet(PRO) group were fed a highfat diet, a high-sugar diet, and a high-protein diet, respectively, in an isocaloric way. All rats were killed at 12 wk. Body weight, visceral fat index(visceral fat/body weight), liver index(liver/body weight), insulin resistance, portal lipopolysaccharide(LPS), serum alanine aminotransferase(ALT), serum aspartate aminotransferase(AST), and liver triglycerides were measured. The intestinal microbiota in the different groups of rats was sequenced using high-throughput sequencing technology.RESULTS The FFAT group had higher body weight, visceral fat index, liver index, peripheral insulin resistance, portal LPS, serum ALT, serum AST, and liver triglycerides compared with all other groups(P < 0.05). Taking the same calories, the RFAT and RSUG groups demonstrated increased body weight, visceral fat index, peripheral insulin resistance and liver triglycerides compared with the PRO group(P < 0.05). The RFAT group also showed increased portal LPS compared with the PRO group(P < 0.05). Unweighted Uni Frac principal coordinates analysis of the sequencing data revealed that the intestinal microbiota structures of the CON, FFAT, RSUG and PRO groups were roughly separated away from each other. Taxon-based analysis showed that, compared with the CON group, the FFAT group had an increased abundance of Firmicutes, Roseburia and Oscillospira bacteria, a higher ratio of Firmicutes to Bacteroidetes, and a decreased abundance of Bacteroidetes, Bacteroides and Parabacteroides bacteria(P < 0.05). The RFAT group showed an increased abundance of Firmicutes and decreased abundance of Parabacteroides bacteria(P < 0.05). The RSUG group showed an increased abundance of Bacteroidetes and Sutterella bacteria, higher ratio of Bacteroidetes to Firmicutes, and a decreased abundance of Firmicutes(P < 0.05). The PRO group showed an increased abundance of Bacteroidetes, Prevotella, Oscillospira and Sutterella bacteria, and a decreased abundance of Firmicutes(P < 0.05). Compared with the FFAT group, the RFAT group had an increased abundance of Bacteroidetes, higher ratio of Bacteroidetes to Firmicutes, and decreased abundance of Firmicutes and Oscillospira bacteria(P < 0.05).CONCLUSION Compared with the high-protein diet, the NAFLDinducing effects of high-fat and high-sugar diets are independent from calories, and may be associated with changed intestinal microbiota.
