Nephroprotective effect of cranberry (Vaccinium oxycoccos) in streptozocin-induced diabetic nephropathy in mice.

OBJECTIVES: Diabetic nephropathy is a chief reason of mortality particularly in individuals with renal dysfunction. The current research was aimed to assess the nephroprotective portion of Vaccinium oxycoccos toward mice diabetic nephropathy induced by streptozotocin (STZ). V. oxycoccos was purchased and used for hydroalcoholic extraction. METHODS: Sixty male mice were subjected to STZ-intraperitoneal injection (45 mg/kg). After diabetes induction, mice were divided into five groups of diabetic control (received only STZ), non-diabetic control (received only citrate buffer), two V. oxycoccos treatment (received V. oxycoccos extract (200 and 400 mg/kg) oral daily by gavage), and metformin treatment (received metformin (500 mg/kg) oral daily by gavage). Glucose and weight of mice were checked weekly. RESULTS: After 28 days, the effect of V. oxycoccos extract on serum and urine parameters were assessed. STZ caused significant decreased in the mice body weight. Mice treated with the V. oxycoccos (400 mg/kg) harbored the lowest weight loss at day 28 (70.2±1.38 g). STZ caused significant increase in the mice FBS. Mice treated with the V. oxycoccos (400 mg/kg) harbored the lowest FBS at day 28 (189.2±1.20 mg/dL). Treatment of mice with V. oxycoccos (400 mg/kg) caused the lowest increase in the levels of cholesterol, HbA1c and triglycerides compared to the diabetic control mice. Compared to the diabetic control group, mice treated with V. oxycoccos (400 mg/kg) had the highest HDL, insulin, SOD, and GSH (p<0.05). The lowest serum BUN, CR, and UR were found in mice treated with V. oxycoccos (400 mg/kg). Anti-inflammatory effects of V. oxycoccos (400 mg/kg) was shown by the lowest TNF-α, IL-6, and TGF-ß1 concentration in mice treated with V. oxycoccos (400 mg/kg). CONCLUSIONS: The current study disclosed that treatment with V. oxycoccos resulted in substantial development in the serum and urine parameters and also antioxidant and anti-inflammatory response of STZ-induced diabetic mice.

Wound healing activity of Salvia huberi ethanolic extract in streptozocin-induced diabetic rats.

Objective: The aim of this study was to examine the in vivo wound healing potential of Salvia huberi Hedge (endemic to Turkey) on excision and incision wound models in diabetic rats. Method: Male Wistar albino rats, 3-4 months old and weighing 180-240g were used. The animals were randomly divided into five groups including Control, Vehicle and Fito reference, and two different concentrations (0.5% and 1% weight/weight (w/w)) of ethanol extract of Salvia huberi were investigated in both wound models on streptozocin-induced diabetic rats using macroscopic, biomechanical, biochemical, histopathological, genotoxic and gene expression methods over both seven and 14 days. Fito cream (Tripharma Drug Industry and Trade Inc., Turkey) was used as the reference drug. Results: A total of 60 rats were used in this study. Salvia huberi ointments at 0.5% and 1% (w/w) concentrations and Fito cream showed 99.3%, 99.4% and 99.1% contraction for excision wounds, and 99.9%, 97.0% and 99% contraction for incision wounds, respectively. In Salvia huberi ointments and Fito cream groups, re-epithelialisation increased dramatically by both day 7 and day 14 (p<0.05). By day 14, low hydroxyproline and malondialdehyde (MDA) levels, and high glutathione (GSH) levels were observed in the Salvia huberi ointment groups. After two application periods, damaged cell percent and genetic damage index values and micronucleus frequency of Salvia huberi ointment treatment groups were lower than Control and Vehicle groups (p<0.001). A growth factor expression reached a high level by day 7 in the Control group; in Salvia huberi-treated groups it was decreased. Conclusion: The study showed that application of Salvia huberi ointments ameliorated the healing process in diabetic rats with excisional and incisional wounds and may serve as a potent healing agent.

Quercus infectoria gall extract aids wound healing in a streptozocin-induced diabetic mouse model.

OBJECTIVE: Quercus infectoria galls have commonly been used for different therapeutic purposes. This study was conducted to investigate the effects of topical application of an ointment prepared from Quercus infectoria gall hydroethanolic extract on open wound healing in a streptozocin-induced diabetic BALB/c mouse model. METHOD: After induction of diabetes, two circular wounds (5mm) were created on the dorsum of the mice which were then divided into three groups. The mice were treated with soft yellow paraffin (control-sham group) and therapeutic doses of 5% and 10% of an ointment prepared from Quercus infectoria, respectively. To evaluate the effects of the therapeutic ointment on the wound healing process, wound area, histological parameters, mRNA levels of vascular endothelial growth factor (VEGF), Bcl-2 and p53, plasma levels of interleukin-6 (IL-6) and tumour necrosis factor (TNF)-α, and tissue antioxidant capacity were investigated. RESULTS: The mice (n=54) were divided into three equal groups. Wound area and concentrations of IL-6 and TNF-α were significantly decreased in both ointment-treated groups compared to the control group (p<0.05). Moreover, angiogenesis, fibroblast distribution per mm2 of wound tissue, collagen deposition, rapid re-epithelialisation, and the expression of VEGF, Bcl-2 and p53 mRNA, were significantly increased (p<0.05). The administration of the ointment reduced malondialdehyde concentration and increased total antioxidant capacity compared with the control group (p<0.05). CONCLUSION: Our study suggests that an ointment prepared from Quercus infectoria gall hydroethanolic extract accelerated open wound healing in a diabetic animal model by shortening the inflammatory phase, inducing apoptosis, up-regulating the expression of Bcl-2 and p53 mRNA, antioxidant properties and cellular proliferation.

Dolichandrone serrulata flower extract ameliorates male reproductive damages in type 2 diabetic rats.

Dolichandrone serrulata flower (DSF) has been believed to reduce blood glucose in hyperglycaemic persons with sub-fertility but its effect on improvement of male reproductive impairment has never been elucidated scientifically. This study attempted to investigate the hypoglycaemic effects of DSF on male reproductive damages in type 2 diabetes mellitus (T2DM) rats. Adult Sprague Dawley rats were divided into four groups (control, T2DM, DSF200 + T2DM and DSF600 + T2DM; n = 10/each). Control rats received low-fat diet for 14 days before saline injection while streptozocin (50 mg/kg BW) induced T2DM groups received high-fat diet and were orally administered with DSF (200 and 600 mg/kg BW) for 28 days. At the end, fasted blood glucose (FBG), malondialdehyde (MDA), testosterone, sperm quality, histology and protein expressions were examined. The result showed that DSF decreased high FBG and testicular MDA and increased testosterone levels of T2DM-treated rats. Low-sperm quality and histological malfunction were ameliorated in DSF-treated group. There was significant decrease in the expression of androgen receptor, heat-shock 70 and steroidogenic acute regulatory proteins of T2DM-treated rats. Our study demonstrated changes of six bands (116, 51, 45, 39, 35 and 29 kDas) of tyrosine-phosphorylated proteins. In conclusion, DSF could reduce the FBGand ameliorate the reproductive damages in male T2DM rats.

Use of bromelain in cutaneous wound healing in streptozocin-induced diabetic rats: an experimental model.

OBJECTIVE: To assess the effect of bromelain on different aspects of the wound healing process in type 1 diabetic rats. METHOD: In this study, 112 streptozocin-diabetic (type 1) male Wistar rats were euthanised; 28 each on days three, five, seven and 15, after a wound incision had been made. To estimate changes in a number of different cellular and tissue elements, histological sections were provided from all wound areas and stained with haematoxylin and eosin. Some 1.056mm2 of total wound area from all specimens were evaluated, by assessment of 4200 microscope photos provided from all histological sections, by stereological methods. A biomechanical test of each wound area was performed with an extensometer to evaluate the work-up to maximum force and maximum stress of the healed wound on day 15. RESULTS: In the experimental groups, bromleain caused significant wound contraction and reduced granulation tissue formation by day 7 (p=0.003); increased neovasculars (new small vessels that appear in the wound area during wound healing) on days three, five and seven (p=0.001); significantly increased fibroblasts on day five but decreased by day seven (p=0.002); and significantly decreased macrophage numbers and epithelium thickness on all days of study (p=0.005). Wound strength significantly increased in experimental groups by day 15. CONCLUSION: Bromelain has a wide range of therapeutic benefits, but in most studies the mode of its action is not properly understood. It has been proved that bromelain has no major side effects, even after prolonged use. According to the results of this study, bromelain can be used as an effective health supplement to promote and accelerate wound healing indices, reduce inflammation and improve biomechanical parameters in diabetic wounds.

The effects of onion (Allium cepa L.) dried by different heat treatments on plasma lipid profile and fasting blood glucose level in diabetic rats.

OBJECTIVE: This study aims to evaluate the effects of onion (Allium cepa L.) against hyperglycaemia and dyslipidemia and determine possible changes in these effects due to different heat treatments applied to onion. MATERIALS AND METHODS: 32 male Wistar-albino rats were divided into 4 groups as follows: the groups C and DC were fed with standard rat diet; the DLO group was fed with rat diet including 5% onion powder dried at -76°C in a lyophilizator, and the DFO group was fed with rat diet including 5% onion powder dried at 80°C in a furnace. Diabetes was induced in DC, DLO and DFO groups by injection of streptozotocin (45 mg/kg). RESULTS: A decreasing tendency was observed in fasting blood glucose (FBG) values of DLO group during the experiment period and it was found that the 6th and 8th weeks values were significantly lower than the 1st and 2nd weeks values (p<0.05). On the other hand, no statistical difference was observed in the FBG values measured at different weeks in the DFO group. Significant differences were also observed among the groups in terms of plasma lipid values. DLO group was determined to have lower levels of triglyceride (p<0.001), LDL cholesterol and total cholesterol and higher levels of HDL cholesterol (p<0.05 for all cases) compared to the DC group whereas no significant difference in these values was found between the DFO and DC groups. CONCLUSION: Lyophilized onion powder may be protective against hyperglycaemia and dyslipidemia arising from diabetes. However, the heat treatments applied to onion affect this protective role negatively.

Effects of Turmeric (Curcuma longa) Extract in streptozocin-induced diabetic model.

Herbal remedies have been used for centuries to ameliorate complications of diabetes mellitus (DM). The aim of this study is to compare the effects of the oral curcumin supplement versus parenteral administration of turmeric extract on diabetic complications in a streptozocin (STZ) diabetic model. STZ DM rats received low and high doses turmeric extract intraperitoneally as well as oral curcumin. Curcumin and turmeric extracts significantly reduced blood glucose and creatinine levels, but not urea, and caused an increase in uric acid. Low dose improved liver enzymes, while higher dose and oral administration caused an increase in the ALT and AST. All groups showed an improvement in the serum cholesterol, while the triglycerides were not improved in the high and oral treatment. Histological evaluation showed islet cell protection. High-dose injection showed almost intact renal corpuscles as well as tubular structures with minimal degeneration. Treatment showed limited protection of Liver tissue. PRACTICAL APPLICATION: Curcumin has been heavily marketed as a protective agent. The current study shows some potential risk of curcumin use. Oral and injectable curcumin should be used with caution. Turmeric extract and oral curcumin supplement showed protective effects on pancreatic, and renal structure and function. Although both did show some improvement in liver function, higher doses caused disturbance in liver enzymes and did not show histological evidence of liver tissue protection.

The freeze-dried extracts of Rotheca myricoides (Hochst.) Steane & Mabb possess hypoglycemic, hypolipidemic and hypoinsulinemic on type 2 diabetes rat model.

ETHNOPHARMACOLOGICAL RELEVANCE: Rotheca myricoides (Hochst.) Steane & Mabb is a plant species used in traditional medicine for the management of diabetes in the lower eastern part of Kenya (Kitui, Machakos and Makueni Counties, Kenya) that is mainly inhabited by the Kamba community. AIM: This study investigated the antihyperglycaemic, antidyslipidemic and antihyperinsulinemic activity of the freeze-dried extracts of Rotheca myricoides (Hochst.) Steane & Mabb (RME) in an animal model of type 2 diabetes mellitus. METHODS: Type 2 diabetes was induced by dietary manipulation for 56 days via (high fat- high fructose diet) and intraperitoneal administration of streptozocin (30 mg/kg). Forty freshly-weaned Sprague Dawley rats were randomly assigned into the negative control (high fat/high fructose diet), low dose test (50mg/kg RME, high dose test (100mg/kg RME and positive control (Pioglitazone, 20mg/kg) groups. Fasting blood glucose and body weight were measured at weekly intervals. Oral glucose tolerance tests were performed on days 28 and 56. Lipid profile, hepatic triglycerides, fasting serum insulin levels and serum uric acid were determined on day 56. RESULTS: The RME possessed significant antihyperglycemic [FBG: 6.5 ±â€¯0.11 mmol/l (negative control) vs. 4.62 ±â€¯0.13 mmol/l (low dose test) vs. 5.25 ±â€¯0.15 mmol/l in (high dose test) vs. 4.33 ±â€¯0.09 mmol/l (positive control): p < 0.0001] and antihyperinsulinemic effects [1.84 ±â€¯0.19 (negative control) vs. (0.69 ±â€¯0.13 (low dose test) vs. (0.83 ±â€¯0.17 (high dose test) vs. (0.69 ±â€¯0.10 (positive control): F (3, 36) = 0.6421: p < 0.0001. The extracts also possessed significant antidyslipidemic effects [LDL levels: 3.52 ±â€¯0.19 mmol/l (negative control) vs. 0.33 ±â€¯0.14 mmol/l (low dose test) vs. 0.34 ±â€¯0.20 mmol/l (high dose test) vs. 0.33 ±â€¯0.01 mmol/l (positive control): p < 0.0001].RME significantly lowered plasma uric acid levels, as well as hepatic triglycerides and hepatic weights. Network pharmacology analysis indicated that the observed pharmacological effects are mediated via the modulation of Peroxisome proliferator-activated gamma receptor. CONCLUSIONS: The freeze dried extracts of Rotheca myricoides possessed significant antihyperglycemic and antidyslidemic effects. In addition it lowered serum uric levels, as well as hepatic triglycerides and hepatic weight. These results appear to validate the traditional use of this plant species in the management of diabetes mellitus.

Pharmacodynamic interaction of cumin seeds (Cuminum cyminum L.) with glyburide in diabetes.

Background and objective The plethora of anti-diabetic agents available today has many side effects, especially on chronic usage. Hence, alternative approaches utilizing natural and synthetic agents are sought after. Cumin has been shown to be beneficial in treating diabetes. This study evaluates the anti-diabetic effect of cumin and glyburide in the streptozotocin induced diabetes model in rats, and investigates their pharmacodynamic interactions and its implication in diabetes. Methodology The phytoconstituents present in the ethanolic cumin seed extract were determined using appropriate analytical methods. After acute toxicity studies (OECD 2001), the anti-diabetic effect of the extract was evaluated in wistar rats. The rats were divided into five groups - Groups I and II served as the normal and diabetic control. Group III was the standard control (glyburide 5 mg/kg), while groups IV and V received the extract (600 mg/kg) and a combination of the extract (600 mg/kg) and glyburide (2.5 mg/kg; half dose). Biochemical parameters viz. plasma glucose and glycosylated haemoglobin, were measured periodically during the 28 day treatment. On the 28th day, oral glucose tolerance test, lipid profile, renal profile and histopathological evaluation were performed after completion of the study. To investigate the nature of herb-drug interaction, HPLC analysis for estimation of glyburide concentration in the blood was conducted. Results Acute toxicity studies showed the extract to be safe till a dose of 2 g/kg. The extract alone, and in combination with glyburide (half-dose), significantly lowered elevated glucose (by more than 45% from baseline; without producing hypoglycemia), and other lipid and renal parameters. The effects produced by 2.5 mg/kg glyburide, and 5 mg/kg glyburide (without extract) were similar. Histopathological analysis also showed that the extract was able to reverse the degeneration brought about by streptozotocin which was especially notable on the pancreatic and renal tissue. HPLC analysis revealed differing pharmacokinetics of glyburide in the groups treated with 5 mg/kg dose, and 2.5 mg/kg + 600 mg/kg extract. Conclusion The results obtained in this study suggest that Cuminum cyminum L. is a promising anti-diabetic agent, and exhibits pharmacodynamic interaction with glyburide to mitigate symptoms of diabetes mellitus.

Prolong treatment with Trans-ferulic acid mitigates bioenergetics loss and restores mitochondrial dynamics in streptozotocin-induced sporadic dementia of Alzheimer's type.

Alzheimer disease has been well associated with mitochondrial dysfunctions. Numerous studies have reported changes in the activity of oxidative phosphorylation (OXPHOS) complexes and mitochondrial dynamics. Recently, dynamin-related protein 1 (Drp-1) has been conceived as a potential therapeutic target as well. We have examined the effect of prolonged treatment of Trans-ferulic acid on streptozocin-induced sporadic dementia of Alzheimer's type. We have found the Ferulic Acid (FA,100 mg/kg) can rescue memory and learning problems and also show significant antioxidant effect while preserving morphology of pyramidal cell layer in hippocampi. Furthermore, FA treatment has shown mitigation in intracerebral-ventricular streptozocin (ICV-STZ) induced bioenergetics loss and dynamic changes by regulating peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1alpha) protein levels in nucleus and hence, mitigating exacerbation of Drp-1 dependent mitochondrial fission and apoptosis by alleviating loss of mitochondrial membrane potential (ΔΨm), downregulating cytochrome-c release into the cytosol by limiting mitochondrial permeability transition pore (mPTP) opening concomitant increase in caspase3 activation, BAX expression and DNA fragmentation along with downregulating glial fibrillary acidic protein (GFAP) expression. FA also restored protein expression of mitofusin2 (Mfn2) a core component of mitochondrial fusion, necessary for mitophagy. We conclude that FA acid may have the propensity to mitigate mitochondrial dysfunction in Alzheimer's disease on prolonging dietary supplementation.

Salidroside stimulates the Sirt1/PGC-1α axis and ameliorates diabetic nephropathy in mice.

BACKGROUND: Salidroside, an active component from Traditional Chinese Medicine Rhodiola rosea L., has various pharmacological functions including anti-inflammatory, anti-cancer and anti-oxidative properties. However, whether salidroside plays a beneficial role in diabetic nephropathy is still unclear. PURPOSE: The objective of this work was to investigate the potential roles of salidroside against diabetic nephropathy and the underlying molecular mechanisms. METHODS: Streptozocin was given to obese mice to generate diabetic nephropathy animal model. Salidroside was administered to these mice and proteinuria, podocyte integrity, renal morphology and fibrosis, mitochondrial biogenesis were examined. RESULTS: Our results showed that salidroside treatment greatly attenuates diabetic nephropathy as evidenced by decreased urinary albumin, blood urea nitrogen and serum creatinine. Morphological analysis indicated that salidroside improves renal structures in diabetic nephropathy. The decreases in nephrin and podocin expression were markedly reversed by salidroside. Moreover, kidney fibrosis in diabetic nephropathy mice was largely prevented by salidroside. Mechanistically, in salidroside-treated mice, the mitochondrial DNA copy and electron transport chain proteins were significantly enhanced. Meanwhile, the reduced Sirt1 and PGC-1α expression in diabetic nephropathy was almost completely counteracted in the presence of salidroside. CONCLUSIONS: Our data showed that salidroside plays a beneficial role against diabetic nephropathy in mice, which probably via Sirt1/PGC-1α mediated mitochondrial biogenesis.

Nigella sativa L. seed regulated eNOS, VCAM-1 and LOX-1 genes expression and improved vasoreactivity in aorta of diabetic rat.

ETHNOPHARMACOLOGICAL RELEVANCE: Nigella sativa L. seed has been widely used in traditional medicine for the treatment of diabetes. The major reason for vascular complications in diabetic patients is endothelial dysfunction. However, the impact of N. sativa seed on endothelial dysfunction in diabetes remains unclear. AIM OF THE STUDY: This study was conducted to evaluate the effect of the hydroalcoholic extract of N. sativa seed on eNOS, VCAM-1, and LOX-1 genes expression and the vasoreactivity of aortic rings to acetylcholine (Ach) in streptozotocin (STZ)-induced diabetic rat. MATERIALS AND METHODS: Treated rats received N. sativa seed extract (100, 200, and 400 mg/kg) daily by gavage for 6 weeks. The fasting blood glucose and lipids were measured and atherogenic index of plasma (AIP) was calculated. The endothelium-dependent vasoreactivity responses of isolated aortic rings were evaluated in the presence of cumulative concentrations of Ach (10-8-10-5 M). eNOS, VCAM-1, and LOX-1 genes expression in aortic tissue was assessed by using real time polymerase chain reaction (PCR). RESULTS: Male diabetic Wistar rats treated with N. sativa seed extract for six weeks reduced serum glucose and lipids and improved AIP. The vasorelaxant responses of aortic rings to Ach were markedly improved. N. sativa seed significantly increased eNOS in mRNA expression level and function, while it decreased VCAM-1 and LOX-1 expressions in vascular cells of aortic tissue which assessed only in mRNA level. CONCLUSIONS: The results of this study showed that N. sativa seed more likely, has antidiabetic and antihyperlipidemic properties and improved vasoreactivity, endothelial dysfunction, and vascular inflammation in diabetic rats' aorta.

Chronic treatment with hydroalcoholic extract of Plathymenia reticulata promotes islet hyperplasia and improves glycemic control in diabetic rats / Tratamento crônico com extrato hidroalcoólico de Plathymenia reticulata promove hiperplasia de ilhotas e controle glicêmico em ratos diabéticos

ABSTRACT Objective: To investigate the anti-hyperglycemic effects of Plathymenia reticulata hydroalcoholic extract and related changes in body weight, lipid profile and the pancreas. Methods: Diabetes was induced in 75 adult male Wistar rats via oral gavage of 65mg/Kg of streptozotocin. Rats were allocated to one of 8 groups, as follows: diabetic and control rats treated with water, diabetic and control rats treated with 100mg/kg or 200mg/kg of plant extract, and diabetic and control rats treated with glyburide. Treatment consisted of oral gavage for 30 days. Blood glucose levels and body weight were measured weekly. Animals were sacrificed and lipid profile and pancreatic tissue samples analyzed. Statistical analysis consisted of ANOVA, post-hoc Tukey-Kramer, paired Student's t and χ2 tests; the level of significance was set at 5%. Results: Extract gavage at 100mg/kg led to a decrease in blood glucose levels in diabetic rats in the second, third (198.71±65.27 versus 428.00±15.25) and fourth weeks (253.29±47.37 versus 443.22±42.72), body weight loss (13.22±5.70 versus 109.60±9.95) and lower cholesterol levels (58.75±3.13 versus 80.11±4.01) in control rats. Extract gavage at 200mg/Kg led to a decrease in glucose levels on the fourth week in diabetic rats, body weight loss in the second, third and fourth weeks in control rats, and lower cholesterol levels in diabetic and control rats. Islet hyperplasia (p=0.005) and pancreatic duct dilation (p=0.047) were observed in diabetic and control rats. Conclusion: Plathymenia extract reduced blood glucose levels in diabetic rats, and body weight in control rats, and promoted pancreatic islet hyperplasia in diabetic and control rats.

RESUMO Objetivo: Avaliar o efeito anti-hiperglicêmico do extrato hidroalcoólico de Plathymenia reticulata, alterações no peso, lipídeos e efeito sobre o pâncreas. Métodos: O diabetes foi induzido pela administração de estreptozotocina 65mg/kg, em 75 ratos Wistar adultos machos, divididos em 8 grupos diferentes: ratos diabéticos e controle + água, ratos diabéticos e controle + 100mg/kg ou 200mg/kg de extrato, ratos diabéticos e controle + gliburida. O tratamento foi realizado por gavagem (oral) por 30 dias. Níveis de glicose e peso foram verificados semanalmente. Os animais foram sacrificados, e amostras de lipídeos e do pâncreas foram analisadas. A análise estatística incluiu ANOVA, post-hoc Tukey-Kramer, teste t de Student pareado e teste do χ2, com nível de significância de 5%. Resultados: O extrato 100mg/kg promoveu redução nos níveis de glicose sanguínea em ratos diabéticos na segunda, terceira (198,71±65,27 versus 428,00±15,25) e quarta semanas (253,29±47,37 versus 443,22±42,72), perda de peso (13,22±5,70 versus 109,60±9,95) e diminuição do colesterol (58,75±3,13 versus 80,11±4,01) em ratos controle. Com extrato de 200mg/kg, houve redução dos níveis de glicose na quarta semana, nos ratos diabéticos; de peso na segunda, terceira e quarta semanas, nos ratos controle; e de colesterol nos animais diabéticos e controle. Ocorreram hiperplasia de ilhotas (p=0,005) e dilatação dos ductos pancreáticos (p=0,047) em ratos diabéticos e controles. Conclusão: O extrato de Plathymenia reduziu os níveis de glicose em ratos diabéticos e de peso em ratos controle, além de ter promovido hiperplasia de ilhotas pancreáticas em diabéticos e controles.

Huangkui capsule, an extract from Abelmoschus manihot (L.) medic, improves diabetic nephropathy via activating peroxisome proliferator-activated receptor (PPAR)-α/γ and attenuating endoplasmic reticulum stress in rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Abelmoschus manihot (L.) medic (AM) is a natural medicinal plant used for the treatment of chronic kidney disease (CKD) in China. Huangkui capsule (HKC), an extract from AM, has been proved clinically effective in improving renal inflammation and glomerular injury in CKD. However, the mechanisms of HKC are still not fully understood. AIM OF THE STUDY: Peroxisome proliferator-activated receptor (PPAR)-α/γ dual agonists have the potential to be used as therapeutic agents for the treatment of type 2 diabetes and diabetic nephropathy (DN). This study evaluated the function of Huangkui capsule (HKC), an extract from Abelmoschus manihot (L.) medic (AM), as a dual agonist for PPARα/γ and investigated its anti-DN effects in a DN rat model. MATERIALS AND METHODS: ChIP and reporter gene assays were performed and the expression of PPARα/γ target genes was monitored to examine the ability of HKC to activate PPARα/γ. DN was induced in male Sprague-Dawley rats via unilateral nephrectomy and intraperitoneal injection of streptozotocin. HKC was administered to the diabetic nephropathy rats at three different doses: high dose HKC (300mg/kg/d); middle dose HKC (175mg/kg/d); and low dose HKC (75mg/kg/d). Irbesartan (4mg/kg/d body weight) was used as a positive control. Following 12 weeks' treatment, we measured general status, renal morphological appearance, proteinuria, blood biochemical parameters, and glomerular morphological changes. The expression of collagen IV, TGFß, TNFα and IL-6 in renal tissue was evaluated. Endoplasmic reticulum (ER) stress in renal tissue was also analyzed. RESULTS: HKC enhanced the transcriptional activity of PPARα and PPARγ in cultured cells, livers and kidneys of DN rats, and it reduced serum triglyceride and cholesterol levels and fat in livers of DN rats. Furthermore, HKC reduced the expressions of inflammatory genes in kidneys of DN rats. Strikingly, HKC reduced ER stress and c-Jun NH2-terminal kinase activation in the liver and kidney of DN rats and subsequently improved renal injury. CONCLUSIONS: Our results show that HKC improved lipid metabolic disorders by activating PPARα/γ and attenuating ER stress. HKC could dose-dependently ameliorate renal inflammation and glomerular injury in DN rats. These results suggest that HKC has potential as an anti-DN agent for the treatment of DN in humans.

Calycosin ameliorates diabetes-induced cognitive impairments in rats by reducing oxidative stress via the PI3K/Akt/GSK-3ß signaling pathway.

Diabetic encephalopathy is one of the most prevalent chronic complications of diabetes mellitus (DM), but there is currently no effective method of prevention nor proven therapeutic regimen for it. In this study, we investigated the effects of calycosin on cognitive behavior and the potential mechanism involved in streptozocin-induced diabetic rats. The effects of diabetes and calycosin treatment on spatial learning and memory were evaluated using the Morris Water Maze, passive avoidance and motor coordination tests. Histological analysis of the hippocampus cornu ammonis 1 (CA1) region was conducted in rats. The decreased expression of the synapsin (SYN) and postsynatptic density protein (PSD-95), as well as brain-derived neurotrophic factor (BDNF) in diabetic rats was measured by quantitative real-time PCR and western blot. Treatment with calycosin promoted a reduction in the expression of SYN, PSD-95 and BDNF. In addition, diabetic rats showed increased MDA levels, and decreased SOD levels and GSH-Px activities in the hippocampus, as well as increased AChE activity in the cerebral cortex; these changes were reversed by calycosin supplementation. Thus, the impairment of learning and memory in STZ-induced diabetic rats was alleviated by calycosin, and that the degree of alleviation was associated with oxidative stress. We also found that calycosin treatment significantly stimulated Akt phosphorylation and decreased GSK-3ß and tau phosphorylation, and that these changes could be restored by the PI3K/Akt inhibitor LY294002. In conclusion, calycosin had a beneficial effect on the amelioration, prevention and treatment of diabetes-associated cognitive deficits, through its involvement in oxidative stress, synaptic function and the PI3K/Akt/GSK-3ß pathway.

Rhizoma Anemarrhenae extract ameliorates hyperglycemia and insulin resistance via activation of AMP-activated protein kinase in diabetic rodents.

ETHNOPHARMACOLOGICAL RELEVANCE: Rhizoma Anemarrhenae has been used in Asian countries for thousands of years to treat diabetes. Insulin resistance (IR) is the primary cause responsible for type 2 diabetes. The aim of this study was to to assess the hypoglycemic and insulin sensitizing properties of Rhizoma Anemarrhenae extract (TFA) in animal models of insulin resistance and/or diabetes and to delineate modes of action. MATERIALS AND METHODS: In-vivo studies were performed on STZ-induced diabetic mice and KK-Ay mice, the former of which were given the extract alone or in combination with insulin for 7 days, and the latter of which were given the extract for 8 consecutive weeks. Fasting blood glucose and serum insulin levels were measured. Pancreatic tissue sections were examined using transmission electron micrographs. Further, hyperinsulinemic-euglycemic clamping study was conducted in BCG vaccine-induced insulin resistance rats, and glucose infusion rate was examined. Mechanisms of action were investigated in 3T3-L1 and Hela cells using Western blot analysis. RESULTS: Our study showed that TFA enhanced the glucose-lowering effects of exogenous insulin administration in STZ-induced diabetic mice. Therapeutic administration of TFA significantly reduced fasting blood glucose, and serum insulin levels, and markedly increased the size and the number of insulin-producing beta cells in KK-Ay mice. Further, hyperinsulinemic-euglycemic clamping study showed that glucose infusion rate was significantly improved in TFA-treated BCG vaccine-induced insulin resistance rats. Study of mechanism of action revealed that TFA increased phosphorylation of AMPK and its downstream target, acetyl-CoA carboxylase (ACC) in 3T3-L1 cells. It activates AMPK in a LKB1-independent manner, providing a unified explanation for the beneficial effects of TFA. CONCLUSIONS: This study that TFA mediates activation of AMPK and improves overall glucose and lipid metabolism in diabetic rodents, highlights the potential utility of TFA for the management of type 2 diabetes.

Thymoquinone and its therapeutic potentials.

Herbal medicine has attracted great attention in the recent years and is increasingly used as alternatives to chemical drugs. Several lines of evidence support the positive impact of medicinal plants in the prevention and cure of a wide range of diseases. Thymoquinone (TQ) is the most abundant constituent of the volatile oil of Nigella sativa seeds and most properties of N sativa are mainly attributed to TQ. A number of pharmacological actions of TQ have been investigated including anti-oxidant, anti-inflammatory, immunomodulatory, anti-histaminic, anti-microbial and anti-tumor effects. It has also gastroprotective, hepatoprotective, nephroprotective and neuroprotective activities. In addition, positive effects of TQ in cardiovascular disorders, diabetes, reproductive disorders and respiratory ailments, as well as in the treatment of bone complications as well as fibrosis have been shown. In addition, a large body of data shows that TQ has very low adverse effects and no serious toxicity. More recently, a great deal of attention has been given to this dietary phytochemical with an increasing interest to investigate it in pre-clinical and clinical researches for assessing its health benefits. Here we report on and analyze numerous properties of the active ingredient of N. sativa seeds, TQ, in the context of its therapeutic potentials for a wide range of illnesses. We also summarize the drug's possible mechanisms of action. The evidence reported sugests that TQ should be developed as a novel drug in clinical trials.

Renoprotection of Danshen Injection on streptozotocin-induced diabetic rats, associated with tubular function and structure.

ETHNOPHARMACOLOGICAL RELEVANCE: Danshen Injection, the aqueous extracts of Radix Salvia miltiorrhiza (S. miltiorrhiza), is one of the most commonly used traditional Chinese herbs in chronic renal failure treatment. In present study, the mechanism of the renoprotective effect of Danshen Injection was analyzed on streptozocin (STZ)-induced diabetic rats. MATERIALS AND METHODS: Diabetic experimental model was established in male Sprague-Dawley (SD) rats by intraperitoneal injection of STZ. Rats with blood glucose concentration of higher than 300 mg/dl were intraperitoneally administered with Danshen Injection at a dose of 0.78 ml/kgday. The blood glucose, 24h urinary protein excretion, serum creatinine (sCr), blood urea nitrogen (BUN), advanced glycation end products (AGEs), lipid peroxide (LPO), antioxidant enzyme of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), transforming growth factor-ß1 (TGF-ß1), and histomorphological changes in kidney of diabetic rats were analyzed during the course of Danshen Injection administration, as well as the tubular function index of albumin reabsorption of fluorescein isothiocyanate labeled bovine serum albumin (FITC-BSA). RESULTS: The intraperitoneal administration of Danshen Injection could ameliorate the physiological dysfunctions of increased 24h urinary protein excretion((48.21 ± 8.04)%), sCr((39.4 ± 3.7)%), and BUN((43.37 ± 6.74)%), alleviate the ultrastructural abnormalities of hypertrophy, matrix expansion, and fibrosis in glomerulus, decrease the TGF-ß1 expression, AGEs and LPO accumulation, and increase the activity of SOD and GSH-Px in kidney of diabetic rats, but did not significantly influence the blood glucose. Besides these, the Danshen Injection administration also partly restored the decrease of megalin expression in tubules and reabsorptive function of FITC-BSA, in diabetic rats. CONCLUSION: The renoprotection of Danshen Injection on diabetic rats was associated with the preservation of tubular function and structure from the hyperglycemia induced toxicities of inappropriate cytokines secretion, oxidative stress, advanced glycation stress, and megalin expression deletion.

Effect of oral administration of magnesium on Cisplatin-induced nephrotoxicity in normal and streptozocin-induced diabetic rats.

BACKGROUND: Cisplatin (CP) therapy as the most common potent chemotherapeutic process is accompanied by nephrotoxicity. The diabetic state may protect rat kidney against this toxicity, and magnesium (Mg) on the other hand may reduce the glucose level in diabetic animals. OBJECTIVES: Current study was planned to investigate the effect of oral administration of magnesium supplementation on CP-induced nephrotoxicity in normal and Streptozocin (STZ)-induced diabetic rats. MATERIALS AND METHODS: Male Wistar rats were divided into seven groups and underwent two experiment protocols. As protocol 1, group 1 was considered as the sham group. Group 2 (CP group) received CP (2 mg/kg/d) for five consecutive days. Group 3 (CP + Mg group) received magnesium sulphate (MgSO4, 10 g/L added to the drinking water) for 10 days and then treated with CP from sixth day. As protocol 2, animals received a single dose of STZ (65 mg/kg i.p.). Three days after diabetes induction, animals were divided into four groups; Groups 4 (D group), 5 (D + CP group), and 7 (D + Mg + CP group) followed the same manner as groups 1 to 3, respectively; and group 6 (D + Mg group) was treated with MgSO4 alone for 10 days. Finally, blood samples were obtained, and all animals were killed for kidney tissue investigation. RESULTS: CP administration in normoglycemic rats significantly elevated the serum levels of blood urea nitrogen (BUN) and creatinine (Cr) (P < 0.05). However, coadministration of CP and Mg statistically increased the serum levels of BUN and Cr in both normoglycemic and diabetic animals when compared to the rats treated with CP alone (P < 0.05), while the serum level of Mg was significantly increased in nondiabetic groups (P < 0.05). No significant changes were observed in serum and kidney levels of nitrite; as well as the testis weight between all normoglycemic groups, whereas Mg decreased kidney levels of nitrite in diabetic groups when accompanied by CP (P < 0.05). The kidney and serum levels of malondialdehyde (MDA) enhanced significantly in nondiabetic rats treated with Mg and CP (P < 0.05). Kidney tissue damage score (KTDS), kidney weight, and body weight loss were significantly different among normoglycemic groups (P < 0.05), and Mg promoted the KTDS in diabetic animals treated with CP. CONCLUSIONS: Oral Mg supplementation did not protect the CP induced nephrotoxicity in diabetic rats.

Berberine ameliorates experimental diabetes-induced renal inflammation and fibronectin by inhibiting the activation of RhoA/ROCK signaling.

The accumulation of glomerular extracellular matrix proteins, especially fibronectin (FN), is a critical pathological characteristic of diabetic renal fibrosis. Inflammation mediated by nuclear factor-κB (NF-κB) plays a critical role in the pathogenesis of diabetic nephropathy (DN). RhoA/ROCK signaling is responsible for FN accumulation and NF-κB activation. Berberine (BBR) treatment significantly inhibited renal inflammation and thus improved renal damage in diabetes. Here, we study whether BBR inhibits FN accumulation and NF-κB activation by inhibiting RhoA/ROCK signaling and the underlying mechanisms involved. Results showed that BBR effectively inhibited RhoA/ROCK signaling activation in diabetic rat kidneys and high glucose-induced glomerular mesangial cells (GMCs) and simultaneously down-regulated NF-κB activity, which was accompanied by reduced intercellular adhesionmolecule-1, transforming growth factor-beta 1 and FN overproduction. Furthermore, we observed that BBR abrogated high glucose-mediated reactive oxygen species generation in GMCs. BBR and N-acetylcysteine inhibited RhoA/ROCK signaling activation in high glucose-exposed GMCs. Collectively, our data suggest that the renoprotective effect of BBR on DN partly depends on RhoA/ROCK inhibition. The anti-oxidative stress effect of BBR is responsible for RhoA/ROCK inhibition in DN.