Protective effect of herbomineral formulation (Dolabi) on early diabetic nephropathy in streptozotocin-induced diabetic rats

Syringic Acid Ameliorates Cardiac, Hepatic, Renal and Neuronal Damage Induced by Chronic Hyperglycaemia in Wistar Rats: A Behavioural, Biochemical and Histological Analysis

This study investigated the effects of syringic acid (SA) on renal, cardiac, hepatic, and neuronal diabetic complications in streptozotocin-induced neonatal (nSTZ) diabetic rats. STZ (110 mg/kg i.p) was injected into Wistar rat neonates as a split dose (second and third postnatal day). Diabetes mellitus was diagnosed in adults by measuring fasting blood glucose levels, urine volume, and food and water intake. The treatment of SA (25 mg/kg, 50 mg/kg p.o) was given from the 8th to 18th postnatal week. To assess the development of diabetic complications and the effect of therapy, biochemical indicators in serum and behavioural parameters were recorded at specific intervals during the study period. SA (25 mg/kg, 50 mg/kg p.o) treatment reduced hyperglycaemia, polydipsia, polyphagia, polyuria, relative organ weight, cardiac hypertrophic indices, inflammatory markers, cell injury markers, glycated haemoglobin, histopathological score, and oxidative stress, and increased Na/K ATPase activity. These findings suggest that SA might significantly alleviate diabetic complications and/or renal, neuronal, cardiac, and hepatic damage in nSTZ diabetic rats.

Erzhi Formula Extracts Reverse Renal Injury in Diabetic Nephropathy Rats by Protecting the Renal Podocytes

Podocytes injury was a crucial factor resulting in diabetic nephropathy (DN). Erzhi formula extract (EZF) was a clinical effective Chinese medicine on DN, but its mechanism was unclear. In this study, the main compounds of EZF and their pharmacokinetics in rat were detected by HPLC-MS/MS. And then, blood glucose, urine protein, renal index, renal microstructural (HE/PAS staining), inflammatory factors (IL-β, TNF-α, IL-6), and protein/mRNA expression related to the function of podocyte (CD2AP and Podocin) in DN rats were investigated after the oral administration of EZF. The concentrations of specnuezhenide and wedelolactone in rat kidney were 7.19 and 0.057 mg/kg, respectively. The T_max of specnuezhenide and wedelolactone were 2.0 and 1.50 h, respectively. Their C_max were, respectively, 30.24 ± 2.68 and 6.39 ± 0.05 μg/L. Their AUC_(0-∞) were 123.30 ± 2.68 and 16.56 ± 0.98 μg/L⁎h, respectively. Compared with the model group, the blood glucose and the 24-hour urinary protein were significantly decreased (P < 0.05) after 16 weeks' treatment of EZF. The expressions of Podocin and CD2AP protein/mRNA were increased (P < 0. 05). The deteriorate of glomerular morphology was alleviated under the treatment of EZF. EZF prominently decreased the levels of inflammatory factors (P < 0.05). MDA was significantly decreased (P < 0.05) with the significant increase of SOD activity (P < 0.05) in EZF groups. All the results proved that EZF repaired glomerular mesangial matrix, protected renal tubule, and improved renal function in DN rats by upregulating the expression of Podocin and CD2AP protein/mRNA in podocytes.

Retracted Article: Ligustrazine attenuates renal damage by inhibiting endoplasmic reticulum stress in diabetic nephropathy by inactivating MAPK pathways

Diabetic nephropathy (DN) is a major cause of chronic kidney disease around the world.

A novel synthetic derivative of quercetin, 8-trifluoromethyl-3,5,7,3',4'-O-pentamethyl-quercetin, inhibits bladder cancer growth by targeting the AMPK/mTOR signaling pathway

Quercetin is a naturally existing compound and shows attractive anticancer properties for a variety of solid tumors including glioma, bladder cancer, hepatocellular carcinoma, breast cancer, hematological malignancies and prostate carcinoma. However, these anticancer properties have not been clinically approved due to unclear mechanistic information and its low bioactivity. In our previous study, we elucidated that quercetin activates AMPK pathway which is the major mechanism for its unique anticancer effect in bladder cancer. In the present study, we are trying to enhance its bioactivity by chemical modification using fluorination approach to prepare novel chemical entities, based on the principle of intermediate derivative method (IDM). The compound we obtained is named 8-trifluoromethyl-3,5,7,3′,4′-O-pentamethyl- quercetin (TFQ), characterized by NMR spectra and mass spectrum (MS). The results from MTT and cologenic assay in two human and one murine bladder cancer cell lines showed that TFQ exhibits more potent inhibition on the three bladder cancer cell lines than quercetin (Que) although this enhanced effects is not very dramatic. Furthermore, we found that the survival of normal bladder cells PEBC was not significantly suppressed by TFQ compared with Que. Western blot analysis showed that TFQ possess more potent AMPK activation than Que. The downstream of AMPK was further examined by western blot. TFQ treatment is able to inactivate mTOR signaling pathway with the regulation of mTOR, 4EBP1 and P70S6K. These results demonstrated that the fluorinated quercetin derivative TFQ inhibits bladder cancer cell growth through the AMPK/mTOR pathway. Altogether, our findings suggest that TFQ could serve as a new potential therapeutic agent for bladder cancer more effective than Que.

Hypoglycemic potential of herbal product dolabi compared with pioglitazone in streptozotocin-induced diabetic rats

OBJECTIVES

To investigate and compare the hypoglycemic potential of commonly used polyherbal formulation dolabi with pioglitazone in streptozotocin-induced diabetic rats.

METHODS

A total of 24 adult male Wistar rats were randomized into diabetic control group, diabetic group receiving dolabi (17.6 mg kg-1 day-1), diabetic group receiving dolabi (35.2 mg kg-1 day-1) and diabetic group receiving pioglitazone (2.7 mg kg-1 day-1), with 6 rats in each group. The study was conducted for 4 weeks. Blood samples were collected for fructosamine estimation, fasting plasma glucose (FPG) and oral glucose tolerance test (OGTT) were measured at different time points.

RESULTS

Compared with baseline, the groups receiving dolabi (35.2 mg kg-1 day-1) and pioglitazone showed signififi cant reductions (P<0.05) in fructosamine levels at the end point and same was the case for FPG and OGTT with pioglitazone showing greater hypoglycemic potential. However, the group receiving dolabi (17.6 mg kg-1 day-1) showed significant reduction (P<0.05) only in FPG level and failed to achieve significant changes either in fructosamine level or OGTT. Moreover, signififi cant differences (P<0.05) in FPG and fructosamine levels were observed between groups receiving dolabi (17.6 mg kg-1 day-1) and pioglitazone at the end point.

CONCLUSIONS

These results showed sluggish hypoglycemic effects of dolabi at manufacturer's recommended doses. At a higher dose however, good glycemic control was achieved with dolabi and the results were comparable to pioglitazone. The shorter duration of study (4 weeks) might be the reason of poor glycemic control associated with dolabi at a normal dose.

BAY 11-7082 ameliorates diabetic nephropathy by attenuating hyperglycemia-mediated oxidative stress and renal inflammation via NF-κB pathway

Diabetic nephropathy is a serious microvascular complication for patients associated with diabetes mellitus. Recent studies have suggested that NF-κB is the main transcription factor for the inflammatory response mediated progression of diabetic nephropathy. Hence, the present study is hypothesized to explore the renoprotective nature of BAY 11-7082 an IκB phosphorylation inhibitor on Streptozotocin (STZ) induced diabetic nephropathy in Sprague-Dawley (SD) rats. Male SD rats were divided into five groups, group I sham control, group II drug control, group III diabetic control (STZ 50mg/kg), group IV and V are test drug groups to which a single dose of STZ 50mg/kg was injected initially and later received BAY 11-7082 1mg/kg and 3mg/kg, respectively from 5th to 8th week. Eight weeks after STZ injection, diabetic rats exhibited significant renal dysfunction, as evidenced by reduced creatinine clearance, increased blood glucose, urea nitrogen and creatinine, which were reversed to near normal by BAY 11-7082. BAY 11-7082 treated rats showed significant improvement in the decreased enzymatic antioxidant SOD, non-enzymatic antioxidant GSH levels, and elevated lipid peroxidation and nitric oxide levels as observed in the diabetic rats. BAY 11-7082 treatment was found to significantly recover kidney histological architecture in the diabetic rats. Altered levels of inflammatory cytokines like TNF-α, IL-1β, IL-6 and nuclear transcriptional factor subunit NF-κB p65 were reverted to the normal level upon treatment with BAY 11-7082. Our results suggest that by limiting the activation of NF-κB, thereby reducing the expression of inflammatory cytokines and by inhibiting the oxidative damage BAY 11-7082 protect the rats against diabetic nephropathy.

Hydroalcohol extract of Trigonella foenum-graecum seed attenuates markers of inflammation and oxidative stress while improving exocrine function in diabetic rats

CONTEXT AND OBJECTIVE

The herb fenugreek, Trigonella foenum-graecum Linn (Fabaceae), seeds have been traditionally used in the treatment of diabetes but its effect on oxidative stress and pro-inflammatory cytokines in the improvement of exocrine function of diabetes has not been studied. The effect of hydroalcoholic extract of Trigonella foenum-graecum seeds (HEF) on alloxan-induced type-II diabetic rat model was investigated.

MATERIALS AND METHODS

Effect of HEF (500, 1000, and 2000 mg/kg), glimepiride (4 mg/kg), and combination of HEF (500 mg/kg) + glimepiride (2 mg/kg), on alloxan-induced diabetic rats was evaluated by assaying (blood glucose, serum protein, glycosylated hemoglobin, muscle and liver glycogen, glucose uptake by diaphragm, liver glucose transport, serum pancreatic enzymes (α-amylase, lipase), pro-inflammatory cytokines (TNF-α, IL-6), antioxidant enzymes [glutathione (GSH), superoxide dismutase (SOD)], lipid peroxides (liver and pancreas), and histoarchitecture (liver, pancreas).

RESULTS

Treatment with HEF (at different doses), glimepiride, and HEF + glimepiride increased body weight and glucose uptake, reduced plasma glucose, glycosylated hemoglobin, liver glucose transport, pro-inflammatory cytokines, pancreatic enzymes and restored depleted glycogen (muscle, liver) and total protein significantly (p < 0.01) and dose dependently, including prevention of lipid peroxidation and restoration of GSH and SOD (liver and pancreas). Treatment with HEF + glimepiride potentiated hypoglycemic activity of glimepiride. Histoarchitecture of liver and pancreas showed marked improvement.

CONCLUSION

Present experimental findings suggest that HEF possesses promising hypoglycemic activity, presumably by amelioration of oxidative stress and pro-inflammatory cytokines. HEF may be useful as an adjuvant with clinically effective antidiabetic drugs in the management of type-II diabetes.

Protective effect of magnesium on renal function in STZ-induced diabetic rats

Background

Diabetic nephropathy is a serious complication of T1D (type one diabetes mellitus). Persistent hyperglycemia and subsequent hypomagnesemia is believed to develop kidney damage by activation of oxidative stress. We conducted this study to investigate the renoprotective effect of magnesium sulfate (MgSO₄) on renal histopathology and oxidative stress in diabetic rats.

Methods

The study included 70 male rats. The animals were divided into seven groups: control (CRL), control receiving MgSO₄ (CRL + Mg1 & CRL + Mg8), diabetic (DM1 & DM8) and diabetic receiving MgSO₄ (DM + Mg1 & DM + Mg8). Rats were given 20 mg/kg (i.p) Streptozocin (STZ) for 5 consecutive days in (MLD) multiple low doses to induce T1D. At day 10 treatment groups were received MgSO₄ (10 g/l) in drinking water, for 1 or 8 weeks. The blood glucose, BUN and creatinine levels were measured. Renal tissue levels of malondialdehyde (MDA) were measured by thiobarbituric acid (TBA) method to evaluate the oxidative stress. Renal histopathology was done using H & E staining method.

Results

Treatment with MgSO₄ significantly decreased the blood glucose in DM + Mg1 and DM + Mg8 groups as compared with DM1 and DM8. Magnesium treatment also decreased serum BUN and tissue level of MDA significantly in both short and long term treatment. The body weight loss and kidney weight to body weight ratio was improved by MgSO₄. Histological results showed there were no differences between DM and DM + Mg groups.

Conclusion

Our findings showed that diabetic nephropathy is associated with high blood glucose level and oxidative stress (significant increase in MDA level). The renal dysfunction and oxidative stress can be improved by magnesium sulfate administration. It is suggested that protection against development of diabetic nephropathy by MgSO₄ treatment involves changes in the blood glucose and oxidative stress.

Therapeutic potential of resveratrol in diabetic complications: In vitro and in vivo studies

BACKGROUND

Various mechanisms with a complex integrating paradigm have been implicated in diabetic complications. The present study was aimed to evaluate the aldose reductase (AR) and advanced glycation end products (AGEs) inhibitory activity of resveratrol (RSV) and its potential in the treatment of diabetic complications such as cataract and nephropathy.

METHODS

RSV was studied for its inhibitory activity against rat lens AR (RLAR) and rat kidney AR (RKAR) in vitro along with its ability to inhibit formation of AGEs. Anticataract activity of RSV was demonstrated using sugar induced lens opacity model in isolated cattle lens. Furthermore the involvement of RSV in streptozotocin-induced diabetic nephropathy was investigated by assessing the key markers of kidney function along with the formation of AGEs. The potent AR inhibitor, fidarestat was as a standard.

RESULTS

RSV exhibited inhibitory activity against RLAR and RKAR with IC50 values of 4.99 μg/ml (21.9 μM) and 5.49 μg/ml (24.5 μM), respectively. It also showed a significant inhibition of AGEs formation in vitro. In sugar-induced lens opacity model, RSV displayed a significant protective effect preventing opacification and formation of polyols in cattle lens. RSV significantly improved glycaemic status and renal function in diabetic rats with a significant decrease in the formation of AGEs in the kidneys.

CONCLUSIONS

The results obtained in this study underline the potential of RSV as a possible therapeutic agent against long-term diabetic complications.

The comparative effects of perindopril and catechin on mesangial matrix and podocytes in the streptozotocin induced diabetic rats

BACKGROUND

Hyperglycemia and advanced glucose end substance (AGE) are responsible for excessive reactive oxygen species (ROS) production, which causes oxidative stress in diabetes mellitus. Oxidative stress and high blood pressure may cause injury and glomerulosclerosis in the kidney. End-stage kidney failure induced by glomerulosclerosis leads to microalbuminuria (Ma) in diabetic nephropathy. We investigated the effects of an angiotensin converting enzyme inhibitor (ACEI), perindopril, and an antioxidant, catechin, on podocytes and the glomerular mesangial matrix in experimental diabetic nephropathy using ultrastructural visualization and immunohistochemical staining.

METHODS

We compared 5 groups of male adult Wistar albino rats: a control group, an untreated diabetic group, and diabetic groups treated with perindopril, catechin, or catechin+perindopril.

RESULTS

Blood glucose values in all diabetic groups were significantly higher than in the control group (p < 0.001). The body weight in all diabetic groups was significantly lower than in the control group (p < 0.001, p < 0.05). The kidney weight in the catechin+perindopril-treated diabetic group was significantly lower than in the untreated diabetic group (p < 0.001). In all treated diabetic groups, Ma levels decreased significantly (p < 0.001). Mesangial matrix and podocyte damage increased in the untreated diabetic group, but the group treated with catechin+perindopril showed less damage. TGF-beta 1 immunostaining was significantly lower in the catechin-treated and perindopril-treated groups than in the untreated diabetic group (p < 0.001). Catechin was more effective than ACEI in preventing podocyte structure. Podocytes appeared to be the first cells affected in diabetes mellitus. When exposed to hyperglycemia, podocytes caused the mesangial matrix to expand.

CONCLUSIONS

Catechin and perindopril were more effective in preventing renal corpuscle damage when administered together.