Study on efficacy of asiaticoside in alleviating diabetic nephropathy in rats and the underlying action mechanism

The aim of the present study was to investigate the effects of the iron chelator deferiprone in diabetic nephropathy (DN) rats and the mechanisms involved. Thirty-two male Wistar rats (180-220 g, 6 weeks old) were randomly divided into a control group, a DN group and two DN groups treated with either 50 or 100 mg/kg per day deferiprone. The DN group was established by feeding of a high-carbohydrate-fat diet and injection of 35 mg/kg streptozotocin into the vena caudalis. The duration of deferiprone treatment was 20 weeks. Histopathological changes were detected by hematoxylin-eosin and Masson staining, as well as transmission electron microscopy. Levels of nuclear factor (NF)-κB, monocyte chemotactic protein (MCP)-1, matrix metalloproteinase (MMP)-9, tissue-specific inhibitor of metalloproteinase (TIMP)-1, cyclo-oxygenase (COX)-2, and nitrotyrosine were determined in kidney tissues using reverse transcription-polymerase chain reaction (RT-PCR), western blotting, and immunohistochemistry. Histopathological observations showed that deferiprone treatment alleviated inflammation infiltrates and collagenous fibrosis in DN rats. Results from RT-PCR and western blotting indicated that deferiprone inhibited the expression of NF-κB, MCP-1, COX-2, and nitrotyrosine, which were overexpressed in DN rats. Immunohistochemistry showed that the mechanism of deferiprone action may involve regulation of MMP-9 and TIMP-1. Decreased MMP-9 expression and increased TIMP-1 expression in DN rats were significantly promoted and inhibited by deferiprone, respectively. Iron chelation by oral deferiprone has a renoprotective effect in DN rats by relieving oxidative stress, inflammation, and fibrosis, which is related to the cytokines NF-κB, MCP-1, MMP-9, TIMP-1, COX-2, and nitrotyrosine.

Sequoyitol decreases blood glucose, improves glucose intolerance, and enhances insulin signaling in ob/ob mice. The aim of this study was to investigate the effects of sequoyitol on diabetic nephropathy in rats with type 2 diabetes mellitus and the mechanism of action. Diabetic rats, induced with a high-fat diet and a low dose of streptozotocin, and were administered sequoyitol (12.5, 25.0, and 50.0 mg·(kg body mass)(-1)·d(-1)) for 6 weeks. The levels of fasting blood glucose (FBG), serum insulin, blood urea nitrogen (BUN), and serum creatinine (SCr) were measured. The expression levels of p22(phox), p47(phox), NF-κB, and TGF-β1 were measured using immunohistochemisty, real-time PCR, and (or) Western blot. The total antioxidative capacity (T-AOC), as well as the levels of malondialdehyde (MDA) and reactive oxygen species (ROS) were also determined. The results showed that sequoyitol significantly decreased FBG, BUN, and SCr levels, and increased the insulin levels in diabetic rats. The level of T-AOC was significantly increased, while ROS and MDA levels and the expression of p22(phox), p47(phox), NF-κB, and TGF-β1 were decreased with sequoyitol treatment both in vivo and in vitro. These results suggested that sequoyitol ameliorates the progression of diabetic nephropathy in rats, as induced by a high-fat diet and a low dose of streptozotocin, through its glucose-lowering effects, antioxidant activity, and regulation of TGF-β1 expression.

Chronic hyperglycemic condition leads to development of diabetic nephropathy (DN). Basella alba is an important edible vegetable in India. Present study was conducted to inquire the effects of methanol extract from Basella alba leaf (MEBA) against diabetic nephropathy in rats. A single intraperitoneal injection of streptozotocin (55 mg/kg) was given to Wistar albino rats to induce diabetes. After 4 weeks of diabetes induction, the rats were divided into normal control group, disease DN group, MEBA treatment groups (200 and 400 mg/kg), metformin treatment group (150 mg/kg) and the treatment was continued for next 3 weeks. In MEBA treated groups there were marked improvements in blood glucose, ALP, ALT, total protein, serum lipid profile such as total cholesterol, triglyceride, HDL levels and renal functions such as urine volume, urinary protein excretion, serum creatinine, blood urea nitrogen, creatinine clearance as compared to non-treated DN group. There was significant rise in malonaldehyde level, and decline in acivites of superoxide dismutase and reduced Glutathione (GSH) of kidney in diabetic rats as compared to normal control group rats. The MEBA treated groups showed dose dependent restoration of altered oxidative stress parameters. Moreover, from renal histopathology it was evident that the abnormal thickening of Glomerular basement membrane in kidney of diabetic rats were improved in MEBA treated rats. From the present study it can be concluded that, Basella alba leaf has marked protective effect against diabetic nephropathy and proteinuria in rats.

To study the effect of a new biphenyl synthetic compound showing interactions with the active site of protein tyrosine phosphatase 1B by docking and molecular dynamics, VMNS2e in streptozotocin-induced diabetic nephropathy in rats with various renal function parameters and renal ultrastructure. Streptozotocin (55 mg/kg)-induced diabetic rats were orally treated once daily with VMNS2e (30, 60, and 120 mg/kg) for 8 weeks. The body weight and blood glucose levels of the rats were recorded during the study period. After 8 weeks of treatment creatinine clearance, urinary protein, blood urea nitrogen, urinary albumin excretion rate, and insulin levels were measured. An ultrastructure study of the kidney tissue was performed and the glomerular basement membrane thickness was measured. Eight weeks of VMNS2e treatment significantly reduced the fasting blood glucose level, attenuated elevating blood urea nitrogen levels, and reduced glomerular basement membrane thickness. It is concluded that VMNS2e treatment at 30 and 60 mg/kg, when given for 8 weeks, partly ameliorated early diabetic nephropathy in diabetic rats.

The present research work was proposed to discover the beneficial roles of ponicidin against the streptozotocin (STZ)-induced diabetic nephropathy (DN)in rats via modulating the oxidative stress and inflammation. The DN was initiated to the Wistar rats via administering 45 mg/kg of STZ and then diabetic animals were supplemented with 50 mg/kg of ponicidin and 150 mg/kg of metformin (standard drug) for 8 weeks. The body weight and food intake of animals were checked every week. The glucose, insulin, and homeostasis model assessment- insulin resistance (HOMA-IR)levels in the serum were assessed using kits. The levels of reactive oxygen species(ROS)accumulation, oxidative stress and antioxidant markers, and pro-inflammatory cytokines were examined using assay kits. The levels of lipid profiles and renal function markers were investigated using respective kits. The renal tissues were analyzed microscopically to detect the histological alterations. The ponicidin treatment effectively decreased the body weight, food intake, HOMA-IR, and HbAlc levels in the DN animals. The levels of ROS and MDA were decreased and superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and glutathione reductase (GR) activities were improved by the ponicidin. The ponicidin also reduced the blood urea nitrogen(BUN), creatinine, lactate dehydrogenase(LDH), and kidney injury molecule (KIM-1) levels. The levels of low-density lipoprotein (LDL), very-low-density lipoprotein (VLDL), free fatty acid (FFA), and total cholesterol (TC) were decreased and the high-density lipoprotein (HDL) level was improved by the ponicidin treatment to the DN rats. The tumor necrosis factor-alpha(TNF-α), interleukin-1β (IL-1β), nuclear factor-kappa B (NF-κB), and IL-6 levels were appreciably attenuated by the ponicidin. The ponicidin also ameliorated the DM-provoked histological alterations in the renal tissues. In conclusion, this study work evidenced that ponicidin has the therapeutic action in ameliorating the development of DN via averting oxidative stress, inflammation, and renal injury. It could be a promising therapeutic agent to treat DN in the future.

To observe the preventive and therapeutic effects of Ginkgo biloba extract (GbE) on early experimental diabetic nephropathy (DN) in rats. After an early DN model was induced by streptozotocin, rats were administered GbE at 3 doses for 12 weeks. Fasting blood glucose, creatinine (Cr), blood urea nitrogen (BUN), urine protein, kidney index, anti-oxidase, advanced glycosylation end products (AGE), collagen IV and laminin, matrix metalloproteinases-2 (MMP-2) and the tissue inhibitor of metalloproteinase-2 (TIMP-2), connective tissue growth factor (CTGF), and transforming growth factor-beta1 (TGF-beta1) mRNA were measured by different methods. The ultrastructural morphology and the thickness of glomerular base membrane (GBM) were observed by a transmission electron microscope. For the GbE-treated DN rats, when compared with the vehicle-treated DN rats, the fasting blood glucose level, Cr, BUN, urine protein level, and the intensity of oxidative stress were significantly decreased. The expression of MMP-2 greatly increased, and TIMP-2 decreased. Also, AGE, either in serum or in renal, the collagen IV, laminin, CTGF levels, and TGF-beta1 mRNA were reduced. Furthermore, both relative grades of mesangium hyperplasia by microscopical observation and the thickness of GBM by electron microscope measurement decreased significantly. GbE has protective effects on several pharmacological targets in the progress of DN and is a potential drug for the prevention of early DN.

To explore the influence and mechanism of overexpression of SOCS2 on diabetic nephropathy (DN) rats and cells. STZ was used to induce male SD rats and SOCS2 was injected into left renal vein. Rats were divided into DN group, DN-Ad-null group and DN-Ad-SOCS2 group. Glucose with high and normal concentration was used to culture HBZY-1 cells and then transfect Ad-SOCS2. HG group, HG-Ad-null group, HG-Ad-SOCS2 group, CG group, CG-Ad-null group, and CG-Ad-SOCS2 group were created. The expression of inflammatory cytokines (MCP-1, TNF-α and IL-6) in kidney tissue of rats, fibrosis related protein (FN, Collagen IV and TGF-β) in kidney tissue and cells of rats, and JAK/STAT signaling pathway related proteins (p-JAK2 and p-STAT3) were tested by western blot. ELISA was used to test the expression of inflammatory cytokines (TNF-α and IL-6) in cells. The expression of inflammatory cytokines in DN rats (MCP-1, TNF-α and IL-6) and cell (TNF-α and IL-6) were increased (P<0.01) significantly. However, SOCS2 could decrease the overexpression of mediated inflammatory cytokines in DN animal models and cell models (P<0.01). The expression of fibrosis related protein in DN rats and cells increased while SOCS2 decreased the overexpression of mediated fibrosis related protein in DN model rats and cells (P<0.01). The expression of JAK/STAT pathway related protein in both DN rats and cells increased and the JAK/STAT signaling pathway was activated. Yet, SOCS2 obviously suppressed the expression of the JAK/STAT signaling pathway as well as the related proteins (p-JAK2 and p-STAT3) in both DN rats and cells. The overexpression of SOCS2 can decrease the expression of inflammatory cytokines and fibrosis related proteins in DN rats and cells, and meanwhile suppress the activation of JAK/STAT signaling pathway mediated by DN.

Pharmacokinetics and pharmacodynamics of rhubarb anthraquinones extract in normal and disease rats

Chitosan-stabilized selenium nanoparticles (CTS-SeNPs) were prepared by reduction technique. Single phase structure of the SeNPs was confirmed using X-ray diffraction (XRD). Transmission Electron Microscope (TEM) showed that the particle size of the samples in the range of 15 nm. This experiment aimed to study the potential effect of (CTS-SeNPs) as a therapeutic factor in diabetic nephropathy in rats. Streptozotocin (STZ) was used to induce diabetes in rats; thirty-six numbers were divided into three groups; control, STZ-induced diabetic, and STZ-induced diabetic rats taken CTS-SeNPs groups at a dose (2 mg Se/kg/d). All groups were given respective treatment orally via gastric tube for 2 month. The obtained data showed that, the diabetic group revealed presence of Microalbuminurea, the indicator of diabetic nephropathy and showed a significant increase in fasting blood glucose, urea, creatinine, TAC and MDA, it is significant that high expression level of TGF-β1 and aldose reductase while the group treated with CTS-SeNPs revealed significant decline in all values compared to the diabetic group. Diabetic group showed a significant decrease in insulin level, GPx and SOD activity while, the treated group showed significant increase in these values compared to the diabetic group. Kidney tissue showed normal histological picture except for mild vascular and glomerular congestion in treated group when compared with diabetic one. Our experiment suggests that CTS-SeNPs can moderate diabetic nephropathy in streptozotocin-induced diabetic rats.

Preventive effects of polysaccharides from Liriope spicata var. prolifera on diabetic nephropathy in rats

This study investigated the protective effects of Moutan Cortex polysaccharides components(MCPC) on the renal tissues of diabetic nephropathy(DN) rats and explored their regulation effect on inflammatory response and oxidative stress. The DN rat model was induced by high-glucose and high-fat diet combined with streptozotocin(STZ), and then the rats were randomly divided into control group, model group, positive group and MCPC high(120 mg·kg~(-1)·d~(-1)), low(60 mg·kg~(-1)·d~(-1)) dose groups. After 12 weeks treatment, blood was taken from the orbit of the rats, and then they were sacrificed before the kidney tissues were collected. The serum and tissues were detected for related biochemical indicators and pathological changes of the kidney. Immunohistochemical methods were used to determine the expression of FN and ColⅣ in the kidney tissue of DN rats. Compared with the model group, blood glucose, serum creatinine, blood urea nitrogen and 24 h urine protein in the MCPC high-dose group were significantly reduced(P&lt;0.01). The results of HE, PAS, Masson staining showed that glomerular basement membrane thickening, Bowman's capsule narrowing and inflammatory cell infiltration in DN rats were improved in the MCPC high-dose group; the activity of T-SOD and GSH-Px in serum significantly increased(P&lt;0.001), and the expression level of FN significantly decreased(P&lt;0.001). The high-dose MCPC treatment could effectively inhibit the abnormal expression of Col Ⅳ(P&lt;0.001) and significantly reduce the levels of AGEs and RAGE in serum(P&lt;0.001), the content of VCAM-1 and IL-1β in serum(P&lt;0.001), and the levels of IL-1β mRNA in kidney tissue(P&lt;0.001), but failed to effectively reduce VCAM-1 mRNA levels in kidney tissues. The high-dose MCPC could significantly improve pathological injury of renal tissue and related renal indicators in DN rats, and achieve renal protection in DN rats mainly by regulating oxidative stress and inflammatory factors.

Syringic acid ameliorates experimental diabetic nephropathy in rats through its antiinflammatory, anti-oxidant and anti-fibrotic effects by suppressing Toll like receptor-4 pathway

To observe the effect of electroacupuncture(EA)on renal function and autophagy-related protein expression in diabetic nephropathy (DN) rats，so as to explore its mechanisms underlying improvement of DN. Male Wistar rats were randomly divided into normal control，DN model and EA groups (n=8 rats in each group). The DN model was established by high-fat diet (for 4 weeks) + streptozotocin (STZ，35 mg/kg，i.p.). EA (2 Hz/15 Hz，1 mA) was applied to bilateral "Shenshu"(BL23)and "Zusanli"(ST36)for 20 min，5 times a week for 6 consecutive weeks. The urine volume in 24 h (24 h-UV) was recorded，the levels of urine protein in 24 h (24 h-UP)，blood urea nitrogen (BUN) and serum creatinine (Scr) were detected by using an automatic biochemical analyzer，and the fasting blood glucose (FBG) was detected using rapid blood glucose paper test. The histopathological changes of glomerulus of the left kidney were observed after periodic acid-Schiff stain (PAS) and the ultra-microstructural changes，the numbers of autophagosomes and autophagic vacuoles of the right kidney were observed by transmission electronic microscope (TEM). The expression and localization of podocyte marker protein Nephrin was detected by using immunofluorescence assay，and the expression levels of autophagy-related proteins microtubule associated protein 1 (LC3)，Beclin-1，p62 and Nephrin in the kidney tissue measured by Western blot. Before treatment,compared with the normal control group，the levels of 24 h-UV，24 h-UP and FBG were significantly increased (P<0.01) in the model and EA groups. After treatment, compared with the normal group，the levels of 24 h-UV，24 h-UP，FBG，BUN，Scr and p62 protein expression were signi-ficantly increased (P<0.01)，and the expression levels of LC3Ⅱ，Beclin-1 and Nephrin proteins and ratio of LC3Ⅱ/Ⅰ were significantly decreased (P<0.01) in the model group. Compared with the model group，the levels of 24 h-UV，24 h-UP，FBG，BUN and p62 were apparently decreased (P<0.01，P<0.05)，while the expression levels of LC3Ⅱ，Beclin-1 and Nephrin proteins and ratio of LC3Ⅱ/Ⅰ were obviously up-regulated (P<0.01，P<0.05) in the EA group. No significant changes were found in the level of Scr after EA (P>0.05) and in the expression levels of LC3 Ⅰ after modeling and EA (P>0.05). Outcomes of PAS showed blurred structure of the glomerulus with obvious proliferation of glomerular mesangial cells，increase of cell matrix，and thickening of basement membrane of the glomerulus and renal tubule，atrophy of epithelia cells of renal tubules and infiltration of inflammatory cells in the renal interstitum; and TEM revealed fusion and exfoliation of some foot processes，bareness or thickening of some basement membrane，and reduction of number of autophagosomes or autophagobubbles in podocytes in the model group，which was relatively milder in the EA group. EA can effectively alleviate kidney damage in DN rats，which may be related to its function in facilitating autophagy in the kidney.

Rhizome of Anemarrhena asphodeloides Bunge (AA, family Liliaceae) has been widely used in China for thousands of years to treat febrile diseases and diabetes. Steroidal saponins from AA show good antidiabetes effects and ameliorate diabetic complications. This study was designed to investigate the effects of sarsasapogenin (Sar), a major sapogenin from AA, on diabetic nephropathy (DN) in rats, and to explore the possible mechanisms. Diabetic rats were divided into 3 groups treated orally with Sar (0, 20, or 60mg/kg) and carboxymethylcellulose sodium, whereas normal rats for Sar (0 or 60mg/kg) and carboxymethylcellulose sodium. We found that chronic treatment with Sar for 9weeks significantly ameliorated renal dysfunction of diabetic rats, as evidenced by decreases in albuminuria, kidney weight index, serum uric acid, and morphologic changes such as extracellular matrix expansion and accumulation (fibronectin and collagen IV levels, etc.). Meanwhile, Sar treatment resulted in decreases in interleukin-18, NLRP3, and activated caspase 1 levels as well as advanced glycation endproducts (AGEs) and their receptor (RAGE) levels in the renal cortex of diabetic rats. However, Sar has no effects on the above indices in the normal rats. Therefore, Sar can markedly ameliorate diabetic nephropathy in rats via inhibition of NLRP3 inflammasome activation and AGEs-RAGE interaction.

Objective: The current investigation analysed the effect of combination of standardized hydroalcoholic extracts of Asparagus racemosus (AR), Centella asiatica (CA) and Plumeria rubra (PR) on glibenclamide (GB) administered in experimentally induced diabetic nephropathy (DN) in Wistar rats. Material and methods: DN was induced in laboratory rats by alloxan monohydrate (160 mg/kg i.p). Rats were given the combination of AR, CA and PR called as ACP (100, 200 and 400mg/kg) along with GB (5mg/kg). Group 1-4 were control, diabetic control, standard GB (10mg/kg), GB (5 mg/kg), while groups 5-7 were given ACP (100, 200 and 400mg/kg) along with GB (5mg/kg) once daily for 30 days. Blood glucose, serum insulin, uric acid, Blood Urea Nitrogen (BUN), creatinine, superoxide dismutase (SOD), albumin, malondialdehyde (MDA), and kidney histopathological examination was done in all experimental animals. Results: ACP along with GB improved the derailed glycaemic status, renal biochemical, oxidative stress parameters in animals. Co-administration of ACP (400mg/kg) with GB (5mg/kg) significantly (p&lt;0.01) decreased BUN, creatinine, uric acid, significantly increased (p&lt;0.05) SOD, significantly (p&lt;0.01) decreased MDA, significantly increased (p&lt;0.05) serum insulin when compared with diabetic control. Histopathological observations corroborated with biochemical parameters. Conclusion: Enhancement in the effectiveness of GB was observed with ACP (400mg/kg). Thus, ACP confers protection by improving renal, oxidative parameters and the restoration of morphological abnormalities in the kidneys.