Selection of modeling time for type 2 diabetes mellitus mouse / 中国应用生理学杂志

OBJECTIVE@#To analyze the changes of blood biochemical index and the pathological changes of myocardium and kidney in type 2 diabetic mouse at different time points, which can provide the basis for the selection of type 2 diabetic modeling time for later research.@*METHODS@#After 6 weeks of feeding with high-fat diet, 24 healthy male ICR mice were injected with streptozocin (STZ, 30 mg/kg) intraperitoneally for 5 days to establish diabetic models. After 9 days, a random blood glucose ≥ 11.1 mmol / L was measured as diabetic mice. 4, 6 and 8 weeks after successfully preparing the diabetic mouse, 8 diabetic mice (a group)would be sacrificed each time. Then the biochemical and pathological conditions were analyzed: ① the indexes of heart and kidney were calculated. ②the serum levels of creatine kinase (CK), lactate dehydrogenase (LDH), creatinine (Cr) and blood urine nitrogen (BUN) were determined. ③ Histopathological changes of myocardium and renal tissues were observed by hematoxylin and eosin (HE) staining. Masson staining was used to observe the fibrosis of myocardium. PAS staining was adopted to observe the pathological changes of renal tissue. In addition, 8 ICR male mice were taken as the control group.@*RESULTS@#At the 4, 6 and 8 week, cardiac organ coefficient, the values of LDH and CK were all increased compared with the control group. Cardiomyocyte hypertrophy and myocardial fibrosis could be observed. Renal organ coefficient, the values of Cr and BUN were increased. Glomerular hypertrophy, basement membrane thickening and atrophy could be perceived.@*CONCLUSION@#At the 6 week, related biochemical and pathological changes in diabetic mice were comparatively obvious and breeding time was relatively short. Thus, 6 weeks after the preparation of the diabetic mice would be the optimal time for type 2 diabetes mellitus modeling, proper for inventions of drugs and other research purposes including pathology, physiology, biochemistry, etc.

Effects of ursolic acid on liver injury and its possible mechanism in diabetes mellitus mice / 中国应用生理学杂志

OBJECTIVES@#To study the effects of ursolic acid on liver injury in diabetic mice induced by high-fat diet combined with streptozotocin(STZ), and to explore its possible mechanisms.@*METHODS@#Diabetes mellitus was induced in twenty male ICR mice by a combination of high-fat diet for 6 weeks with low-dose streptozotocin (30 mg/kg, i. p.) for 5 consecutive days. After 9 days, fasting blood glucose levels were determined. Mice with fasting blood glucose levels exceeded 11. 1 mmol/L were diagnosed as diabetic mice and selected for further experiment. These mice were randomly divided into two groups(each group of 10):diabetic group, ursolic acid group (100 mg/kg, i. g.), and another 10 mice were set as control group. After continuous administration for 8 weeks, body weight (BW) were weighed, fasting blood glucose (FBG), total cholesterol (TC), triglyceride (TG), alanine aminotransferase (ALT), aspartate transaminase (AST) in serum and superoxide dismutase (SOD), malondialdehyde (MDA) in liver were measured. HE staining was used to observe pathological changes of liver tissue.@*RESULTS@#Compared with the control group, the level of FBG, TC, TG, ALT, AST, MDA were dramatically increased (<0. 05, <0. 01) and SOD was markedly decreased (<0.01) in the diabetic group; HE staining showed that parts of liver cells swelled and had a light fatty degeneration as well as lymphocyte infiltrated around the portal area in model group. Compared with the diabetic group, the level of FBG, TC, TG, ALT, AST, MDA were significantly declined (<0.05, <0.01) and SOD was considerably increased (<0.01) in the ursolic acid group; HE staining showed that the liver cells relatively arranged in order, edema was not obvious and inflammatory cells infiltrated lightly in the ursolic acid group.@*CONCLUSIONS@#Ursolic acid has a protective effect on liver injury in diabetic mice induced by high-fat diet combined with STZ by intraperitoneal ingector, and its mechanism may be associated with lowering blood glucose, regulating the lipid metabolism, reducing oxidative stress and enhancing the ability of anti-oxidation in liver.

Effect of ursolic acid on cardiomyopathy of mice with diabetes and its mechanism / 中国应用生理学杂志

OBJECTIVE@#To study the effect of ursolic acid on cardiomyopathy in mice with diabetes induced by high-fat diet combined with low dose streptozotocin, and to explore its possible mechanism.@*METHODS@#Thirty male ICR mice were randomly divided into control group (=10) and moulding group (=20), the mice in the two groups were fed with regular diet and high-fat diet respectively for 6 weeks, and then the mice in the moulding group were injected with streptozotocin (30 mg/kg) for 5 successive days to induce diabetes mellitus (DM). Fasting blood glucose (FBG) was measured after 9 days. Mice with FBG over 11.1 mmol/L were regarded as DM. Twenty DM mice were randomly divided into model group and ursolic acid group (=10). Mice in each group were continuously administrated ursolic acid (100 mg/kg) or corresponding solvent intragastrically for 8 weeks. After that, FBG was measured, body weight (BW), heart weight and left ventricular weight were weighed in order to calculate the heart mass index (HMI) and left ventricular mass index (LVMI). Levels of creatine kinase (CK), lactate dehydrogenase (LDH) in serum and the level of superoxide dismutase (SOD), malondialdehyde (MDA) in myocardial tissue were detected. HE staining was used to observe pathological changes of myocardial tissue. Immunohistochemistry was employed to determine the expression of NOD-like receptor protein 3 (NLRP3) and interleukin 1β (IL-1β).@*RESULTS@#Compared with the control group, HMI, LVMI were apparently enlarged, levels of FBG, CK, LDH in serum and MDA in myocardial tissue were extremely increased, while the activity of SOD in myocardial tissue were extraordinary decreased in diabetic group. HE staining of myocardium showed that arrangement disorder of myocardial fibers, edema and hypertrophy in myocardial cell, as well as inflammatory cell infiltration in model group. Immunohistochemistry showed that the expression of NLRP3 and IL-1β in myocardial tissue increased obviously in model group, the above changes inursolic acid group were significantly ameliorated.@*CONCLUSIONS@#Ursolic acid has a obvious protective effect on myocardial injury in mice with diabetes induced by high-fat diet combined with low dose streptozotocin, and its mechanism may be associated with inhibiting NLRP3 inflammasome activation, reducing IL-1β generation and alleviating myocardial inflammatory injury.

Total triterpene acids, isolated from Corni Fructus, ameliorate progression of renal damage in streptozotocin-induced diabetic rats / 中国结合医学杂志

<p><b>OBJECTIVE</b>To investigate whether total triterpene acids (TTAs), isolated from Cornus Fructus, attenuates renal function by reducing oxidative stress and down-regulating the expression of transforming growth factor β1 (TGF-β1).</p><p><b>METHODS</b>Diabetes was induced by an injection of streptozotocin (40 mg/kg intravenously). Thirty rats were randomly divided into three groups: control group, diabetic model group and TTAs treatment group (50 mg/kg, intragastrically) administrated for 8 weeks from 5th to 12th week. All rats were anaesthetized and then were killed to remove kidneys. The renal function and redox enzyme system parameters were tested. Glomerular morphology was observed by a light microscopy. Immunohistochemistry and Western blot assays were employed to determine the protein levels of TGF-β1.</p><p><b>RESULTS</b>TTAs attenuated the levels of urinary protein, serum creatinine and blood urea nitrogen, although it did not significantly reduce the level of glucose. In addition, TTAs decreased the malondialdehyde while increased superoxide dismutase, catalase and glutathione peroxide activities in diabetic rats. The renal pathological changes in TTAs treatment group were ameliorated. Furthermore, TTAs also ameliorated the expression of TGF-β1.</p><p><b>CONCLUSION</b>TTAs improved renal function via reducing oxidative stress and down-regulation the expression of TGF-β1 in diabetic rats.</p>

Study on the protective effect of ursolic acid on alloxan-induced diabetic renal injury and its underlying mechanisms / 中国应用生理学杂志

<p><b>OBJECTIVE</b>To investigate the effect of ursolic acid (UA) on the alloxan-induced kidney injury in diabetic mice and explored its possible mechanisms.</p><p><b>METHODS</b>Diabetes mellitus was induced in male Kunming mice by an injection of alloxan (70 mg/kg, i.v.). After 72 hours, blood glucose levels were detected and mice with blood glucose levels over 13.9 mmol/L were considered as diabetic and selected for further experiment. Thirty mice were randomly divided into three groups: control, diabetic and diabetic + UA(35 mg/kg/d, i.g. continuously for 8 weeks). Blood glucose concentration, organ coefficient of kidney, blood urea nitrogen (BUN), creatinine (Cr) as well as renal tissue levels of superoxide dismutase (SOD), methane dicarboxylic aldehyde (MDA), tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) were determined. Pathology of the renal tissue was measured by hematoxylin-eosin staining.</p><p><b>RESULTS</b>Compared to the control group, blood glucose, organ coefficient of kidney, BUN and Cr increased significantly. In addition, SOD activities was reduced markedly and levels of MDA and inflammatory factors (TNF-α, IL-6) increased significantly. Renal cells from model group rats showed atrophy and disordered after HE staining and infiltration of inflammatory cells also appeared in renal tissue of the model group. These changes were significantly attenuated in the diabetic group treated with UA.</p><p><b>CONCLUSION</b>UA can significantly relieve renal damage in mice with diabetic nephropathy induced by alloxan, which might be related to decreased blood glucose level, antioxidation effect and inhibiting the production of inflammatory factors such as TNF-α and IL-6.</p>

Protective effect of total flavonoids of epimedium on the kidney in experimental diabetic rats / 中国应用生理学杂志

<p><b>OBJECTIVE</b>To investigate the influence of total flavonoids of epimedium (TFE) on the streptozocin (STZ)-induced kidney injury in diabetic rats and discuss the possible mechanism.</p><p><b>METHODS</b>Diabetes was produced by a single injection of streptozocin (40 mg/kg, iv) in male SD rats. The rats were randomly divided into three groups (n = 10): control group, model group and TFE group (100 mg/kg, ig). Animals were sacrificed 12 weeks later. The level of blood glucose, blood urea nitrogen (BUN) and creatinine (Cr) as well as the renal index were determined. Detect the specific biochemical of renal tissue: superoxide dismutase (SOD), malondialdehyde (MDA). Use masson staining to observe the morphology of the renal tissue. Immunohistochemistry was employed to determine the protein levels of transforming growth factor-beta1 (TGF-beta1).</p><p><b>RESULTS</b>Compared to control group, the enhancement of blood glucose, renal index, BUN and Cr was found in model group, which was significantly attenuated by treatment with TFE. Meanwhile, elevated MDA level in renal tissue as well as decreased SOD activities in renal tissue were significantly remitted by TFE. Furthermore, TFE decreased the expression of TGF-beta1.</p><p><b>CONCLUSION</b>TFE can evidently relieve renal damage in rats with diabetic nephropathy induced by STZ, which might be related to antioxidation and modulating the expression of TGF-beta1 protein.</p>

Amelioration of icariin for the epididymis impairment induced by streptozocin (STZ) in rats / 中国应用生理学杂志

<p><b>OBJECTIVE</b>To investigate the effects of icariin on the streptozocin (STZ)-induced epididymis impair in rats.</p><p><b>METHODS</b>The epididymis impair was induced by injection of streptozocin at dosage of 60 mg/kg ip in SD rats. Animals were randomly divided into six groups (n = 14): normal control, model group, three icariin treated group with different dosages (P.O, 20 mg/kg, 40 mg/kg, 80 mg/kg especially) and rosiglitazone group (P.O, 3 mg/kg), 12 weeks later, animals were sacrificed. The level of serum glucose, the activity of lactate dehydrogenase (LDH), acid phosphatase (ACP), gamma-glutamyltranspeptidase (gamma-GT), alpha-glucosidase activity as well as sialic acid (SA), fructose level in the epididymis were determined. The pathological examination was performed under microscope after the epididymis was fixed by 4% poly-formalin and stained by HE.</p><p><b>RESULTS</b>Compared with the normal control, the activity of LDH, ACP, gamma-GT and alpha-glucosidase in the epididymis revealed a decline, with lower level of SA and fructose. Histological examination showed that mature spermatocytes in the epididymis markedly decreased. These alterations were ameliorated in the groups with the treatment of icariin at 40 mg/kg and 80 mg/kg, but not at 20 mg/kg.</p><p><b>CONCLUSION</b>Icariin ameliorated the signs of epididymis in diabetic rats induced by streptozocin, this effect might carry out by promoting the elevation of special enzyme and energy metabolism in the epididymis.</p>

Study on the effect of ursolic acid (UA) on the myocardial fibrosis of experimental diabetic mice / 中国应用生理学杂志

<p><b>OBJECTIVE</b>To investigate the effect of ursolic acid (UA) on the alloxan-induced myocardial fibrosis in mice and discuss the possible mechanism.</p><p><b>METHODS</b>Diabetes was produced by a single injection of alloxan (70 mg/kg, i.v.) in mice. The mice were randomly divided into four groups: normal control group, model group, ursolic acid group (UA, 35 mg/kg, p.o.) and benazepril group (5 mg/kg, p. o.), and continuous administrated for 8 weeks. The blood glucose was measured 24 hours after the last administration. Detected the specific biochemical of myocardial tissue: superoxide dismutase (SOD), malondialdehyde (MDA) and hydroxyproline(HYP). Using masson staining to observe the morphology of the myocardial tissue. Immunohistochemistry was employed to determine the protein levels of TGF-beta1.</p><p><b>RESULTS</b>Compared to normal group, the blood glucose, heart index, myocardial tissue MDA, HYP level were increased, and SOD activities were decreased in the diabetic mice, Masson stain showed that myocardial cells disarranged, myocardial collagen fibrosis hyperplasia. Meanwhile, the protein expression of TGF-beta1 was increased in model group. The UA group improved all the above significantly.</p><p><b>CONCLUSION</b>UA improves the myocardial collagen fibrosis in diabetic mice induced by alloxan, its mechanism may be related to inhibiting the expression of TGF-beta1 and antioxidation.</p>

Protective effect of total flavonoids of herba epimedii on testis degeneration in diabetic mice / 中国应用生理学杂志

<p><b>OBJECTIVE</b>To observe the protective effects and investigate the possible mechanism of total flavonoids of herba epimedii (TFE) on diabetic testopathy in mice.</p><p><b>METHODS</b>Diabetic animal model was produced by a single injection of alloxan ( 70 mg/kg, i.v.) in mice. The mice were randomly divided into 3 groups (n = 10): control group, model group and TFE group (100 mg/kg, p.o.), administrated for 8 weeks continuously. The level of serum testosterone and blood glucose were measured after 24 hours in the last administration. Detect the specific biochemical indicators of testis: superoxide dismutase (SOD), malondialdehyde (MDA). Meanwhile, the morphology of testis was observed under light microscope by HE and MASSION dyeing. Immunohistochemistry was employed to detect the level of matrix metalloprotein (MMP)9.</p><p><b>RESULTS</b>Compared with control group, glucose and the content of MDA in testicular tissues increased while the levels of serum testosterone and SOD decreased remarkably in model group. Detection of pathology showed that the diameters of seminiferous tubules, various grades of spermatogenic cell decreased and collagen fibrosis hyperplasia in testicular tissues, the expression of (MMP9) were decreased in model group. These alterations were significantly improved in TFE group (P < 0.01).</p><p><b>CONCLUSION</b>TFE ameliorated the alterations of testis inalloxan-induced mice through promoting the testosterone release, anti-oxidation and improving the expression of MMP9.</p>

Protective effect of terpenes from fructus corni on the cardiomyopathy in alloxan-induced diabetic mice / 中国应用生理学杂志

<p><b>OBJECTIVE</b>To investigate the protective effects of terpenes from fructus corni (TFC) on diabetic cardiomyopathy (DCM).</p><p><b>METHODS</b>Diabetes was produced by a single injection of alloxan (220 mg/kg, i.p.) in mice. The fasting blood glucose of mice were tested 15 days later and that greater than 13.9 mmol/L were regarded as the diabetic mice which were divided randomly into the model and TFC groups. TFC dissolved by physiological saline (P.O, 80 mg/kg) was administrated to the TFC group for successive 8 weeks since the 15th day.</p><p><b>RESULTS</b>Compared to the control group, the weight index increased significantly. The level of superoxide dismutase (SOD) was markedly decreased and malondialdehyde(MDA), the inflammatory factors (TNF-alpha, IL-6) were obviously increased in myocardium. The histopathological examination suggested that myocardial cells disarranged, swelling and the intercellular space increased in model group. It also showed the infiltration of inflammatory cells and fibroblasts in TFC group. The above change was improved significantly.</p><p><b>CONCLUSION</b>TFC ameliorated the alterations of cardiomyopathy in diabetic mice induced by alloxan. the mechanism might be related to decrease blood glucose, antioxidative stress and inflammatory factors.</p>