Voluntary exercise improves pulmonary inflammation through NF-κB and Nrf2 in type 2 diabetic male rats.

Objectives: This study aimed to evaluate the effects of voluntary exercise as an anti-inflammatory intervention on the pulmonary levels of inflammatory cytokines in type 2 diabetic male rats. Materials and Methods: Twenty-eight male Wistar rats were divided into four groups (n=7), including control (Col), diabetic (Dia), voluntary exercise (Exe), and diabetic with voluntary exercise (Dia+Exe). Diabetes was induced by a high-fat diet (4 weeks) and intraperitoneal injection of streptozotocin (35 mg/kg), and animals did training on the running wheel for 10 weeks as voluntary exercise. Finally, the rats were euthanized and the lung tissues were sampled for the evaluation of the levels of pulmonary interleukin (IL)-10, IL-11, and TNF-α using ELISA, and the protein levels of Nrf-2 and NF-κB using western blotting and tissue histopathological analysis. Results: Diabetes reduced the IL-10, IL-11, and Nrf2 levels (P<0.001 to P<0.01) and increased the levels of TNF-α and NF-κB compared to the Col group (P<0.001). Lung tissue levels of IL-10, IL-11, and Nrf2 in the Dia+Exe group enhanced compared to the Dia group (P<0.001 to P<0.05), however; the TNF-α and NF-κB levels decreased (P<0.001). The level of pulmonary Nrf2 in the Dia+Exe group was lower than that of the Exe group while the NF-κB level increased (P<0.001). Moreover, diabetes caused histopathological changes in lung tissue which improved with exercise in the Dia+Exe group. Conclusion: These findings showed that voluntary exercise could improve diabetes-induced pulmonary complications by ameliorating inflammatory conditions.

Bone marrow-derived c-kit positive stem cell administration protects against diabetes-induced nephropathy in a rat model by reversing PI3K/AKT/GSK-3ß pathway and inhibiting cell apoptosis.

Stem cell-based therapy has been proposed as a novel therapeutic strategy for diabetic nephropathy. This study was designed to evaluate the effect of systemic administration of rat bone marrow-derived c-kit positive (c-kit+) cells on diabetic nephropathy in male rats, focusing on PI3K/AKT/GSK-3ß pathway and apoptosis as a possible therapeutic mechanism. Twenty-eight animals were randomly classified into four groups: Control group (C), diabetic group (D), diabetic group, intravenously received 50 µl phosphate-buffered saline (PBS) containing 3 × 105 c-kit- cells (D + ckit-); and diabetic group, intravenously received 50 µl PBS containing 3 × 105 c-Kit positive cells (D + ckit+). Control and diabetic groups intravenously received 50 µl PBS. C-kit+ cell therapy could reduce renal fibrosis, which was associated with attenuation of inflammation as indicated by decreased TNF-α and IL-6 levels in the kidney tissue. In addition, c-kit+ cells restored the expression levels of PI3K, pAKT, and GSK-3ß proteins. Furthermore, renal apoptosis was decreased following c-kit+ cell therapy, evidenced by the lower apoptotic index in parallel with the increased Bcl-2 and decreased Bax and Caspase-3 levels. Our results showed that in contrast to c-kit- cells, the administration of c-kit+ cells ameliorate diabetic nephropathy and suggested that c-kit+ cells could be an alternative cell source for attenuating diabetic nephropathy.

Troxerutin affects nephropathy signaling events in the kidney of type-1 diabetic male rats.

Objective: Nephropathy is known to be the leading cause of kidney failure in diabetic patients. Troxerutin, as a flavonoid component, could provide a novel protective strategy in the prevention of diabetic nephropathy. A large number of reports on the salutary effects of troxerutin inspired us to investigate its effect on the nephropathy signaling events (i.e., expression of TGF-ß, miRNA192, and SIP1) in type-1 induced diabetic rats. Materials and Methods: 50 male Wistar rats were divided into 5 groups including control group, sham group treated with troxerutin for 4 weeks, diabetic group induced by streptozotocin (STZ) injection, DI group including insulin-treated diabetic animals and DT group treated with troxerutin. Ultimately, rat kidneys were extracted, and the level of miR-192 (using qPCR), transforming growth factor-beta (TGF-ß), and smad interacting protein 1 (SIP1) using an ELISA kit, was measured. Results: The level of TGF-ß and miRNA192 significantly increased in the diabetic group. However, their expression levels decreased following the administration of troxerutin and insulin (p<0.05) compared to control group. SIP1 was down-regulated in the diabetic group, whereas a spike in the expression levels was observed after troxerutin administration compared to control and troxerutin groups (p<0.05). However, no significant difference was found in the effects of insulin and troxerutin on the level of miR-192, SIP1, and TGF- ß. Conclusion: According to the previous literatures, during the progression of nephropathy, TGF-ß represses SIP1 (the repression region in the collagen gene) by increasing the expression of miR-192. Ultimately, in this study, diabetes led to up-regulation of TGF-ß while troxerutin proved to have a protective effect on the kidney by increasing SIP and lowering miR-192 levels.

Effect of ghrelin on hypoxia-related cardiac angiogenesis: involvement of miR-210 signalling pathway.

OBJECTIVE: Hypoxia is the main stimulus for angiogenesis. Hypoxia-inducible factor (HIF)-1α, vascular endothelial growth factor (VEGF), and miR-210 are involved in the hypoxia-induced angiogenesis. This study examined the effects of hypoxia and/or ghrelin on miR-210, HIF-1α, and VEGF levels in the heart of rats. METHODS: Wistar rats were randomly divided into 4 groups (n = 6): control; ghrelin, received daily intraperitoneal injections of ghrelin; hypoxia, was exposed to hypoxic condition; hypoxia + ghrelin, was exposed to hypoxic condition and received intraperitoneal injections of ghrelin, for 2 weeks. Myocardial angiogenesis, the expression level of miR-210, and protein levels of HIF-1α and VEGF were assayed in the heart samples. RESULTS: Hypoxia increased myocardial angiogenesis and cardiac levels of miR-210, HIF-1α, and VEGF. However, ghrelin inhibited these hypoxia-induced changes. Interestingly, ghrelin had no significant effect on miR-210, HIF-1α, and VEGF levels in normoxic condition. CONCLUSION: Ghrelin may be useful as an anti-angiogenic factor.

Administration of troxerutin improves testicular function and structure in type-1 diabetic adult rats by reduction of apoptosis.

OBJECTIVE: The glucose-reducing effects of troxerutin was previously proven. This study was conducted to evaluate troxerutin effect on testicular structure and spermatozoid parameters in type-1 diabetic adult male rats. MATERIALS AND METHODS: Fifty male Wistar rats were randomly classified into 5 groups as follows: control (C), troxerutin (T), diabetic (DM), troxerutin-treated DM (DT) and insulin-treated DM (DI). Testicular structure, apoptosis, lipid peroxidation and antioxidant activity, and spermatozoid parameters were assessed 4 weeks after initiation of the interventions. RESULTS: The results revealed that diabetes caused testicular stereological changes and significantly increased blood glucose level, testicular MDA content and apoptosis but decreased insulin level, testicular GPX activity, and sperm parameters compared to controls (p<0.001 to p<0.05). Administration of troxerutin and insulin could significantly reduce blood glucose level and improve testicular MDA content, testicular stereological findings and apoptosis compared to DM group (p<0.001 to p<0.05). CONCLUSION: Taken together, troxerutin, comparable to insulin, effectively improved DM-induced testicular dysfunction and sperm parameters in diabetic rats and these effects might be mediated through troxerutin's anti-apoptotic effects.

Troxerutin affects the male fertility in prepubertal type 1 diabetic male rats.

OBJECTIVES: Diabetes can gradually cause damage to the function and structure of male gonads. This survey was conducted to investigate the effect of troxerutin on hormonal changes, serum oxidative stress indices, and testicular function and structure in prepubertal diabetic rats. MATERIALS AND METHODS: Fifty prepubertal (6 weeks old) male Wistar rats were divided into five groups including Control, Troxerutin, Diabetic, Diabetic+Troxerutin, and Diabetic+Insulin. Type I diabetes was induced by 55 mg/kg of streptozotocin intraperitoneally. The groups were treated with 150 mg/kg/day troxerutin via oral gavage or 4-6 IU/day insulin via subcutaneous injection for 4 consecutive weeks. Blood sugar (BS) and serum levels of insulin, FSH, LH, testosterone, glutathione peroxidase (GPX), superoxide dismutase (SOD), malondialdehyde (MDA), and total antioxidant capacity (TAC) were analyzed. Testis and epididymis were removed for histopathologic study and analysis of sperm parameters. RESULTS: Troxerutin significantly reduced the BS in the diabetic group similar to insulin but could not affect insulin, FSH, or LH significantly. Troxerutin caused a significant increase in testosterone and GPX but had no significant effect on serum MDA, TAC, and SOD levels. In addition, troxerutin had a better effect than insulin on diabetes-induced testicular structural damage. Sperm analysis results also revealed that troxerutin and insulin could improve sperm number, motility, and viability in diabetic rats. CONCLUSION: According to these results, it can be derived that administration of troxerutin is a suitable protective strategy for side effects of diabetes in testis of prepubertal diabetic male rats.

Troxerutin protects hippocampal neurons against amyloid beta-induced oxidative stress and apoptosis.

Alzheimer's disease (AD) is an age-related neurodegenerative disease linked with increased production and/or deposition of amyloid-beta (Aß) in the brain. The aim of the present study was to investigate the possible neuroprotective effect of troxerutin on an animal model of Alzheimer's disease. Alzheimer model was induced by a single dose intracerebroventricular (ICV) injection of Aß 1-42 (5 nmol/5 µl). Thereafter, troxerutin (300 mg/kg) was gavaged for 14 days. The hippocampal malondialdehyde (MDA) levels and enzymatic activities of superoxide dismutase (SOD), glutathione peroxidase (GPx), and acetylcholinesterase (AChE) were measured using enzyme-linked immunosorbent assay (ELISA) method. In addition, the number of apoptotic cells in the dentate gyrus (DG) was assessed by TUNEL kit. The results showed that ICV microinjection of Aß 1-42 increased MDA levels, reduced SOD and GPx, and increased AChE activities in the hippocampus. Chronic administration of troxerutin significantly attenuated MDA levels and AChE activity and increased SOD and GPx activities in the hippocampus. Moreover, the number of apoptotic cells was decreased by troxerutin treatment. Taken together, our study demonstrated that troxerutin could increase the resistance of hippocampal neurons against apoptosis, at least in part, by diminishing the activity of AChE and oxidative stress. Therefore, troxerutin may have beneficial effects in the management of Alzheimer's disease.

Ghrelin Decreases Angiogenesis, HIF-1α and VEGF Protein Levels in Chronic Hypoxia in Lung Tissue of Male Rats.

PURPOSE: Hypoxia is a condition of decreased availability of oxygen. When cells are exposed to a low oxygen environment, they impel the hypoxia responses to adapt to new situation. The hypoxia response leads to the activation of various cellular signaling pathways. The aim of this study was to evaluate the effect of ghrelin on angiogenesis, Hypoxia-Inducible-Factor-1α (HIF-1) and Vascular endothelial growth factor (VEGF) levels in normobaric hypoxia situation. METHODS: Twenty four animals were divided into 4 groups (n=6): control (C), ghrelin (Gh), hypoxia (H), and hypoxic animals that received ghrelin (H+Gh). Hypoxia (11%) was induced by an Environmental Chamber System GO2 Altitude. Animals in ghrelin groups received a subcutaneous injection of ghrelin (150 µg/kg/day) for 14 days. RESULTS: Our results showed that hypoxia significantly (p<0.05) increased angiogenesis without any significant changes on HIF-1 and VEGF levels, whereas ghrelin significantly (p<0.05) decreased angiogenesis, expression of HIF-1 and VEGF in this condition. Ghrelin administration did not show any significant changes in normal conditions. CONCLUSION: Ghrelin had no effect on angiogenesis, expression of HIF-1 and VEGF in normal oxygen conditions but it reduced angiogenesis process in lung tissue with reducing the level of HIF and VEGF in hypoxic condition. Therefore, effect of ghrelin on angiogenesis could be related to blood oxygen level.

The Relaxant Effects of Different Methanolic Fractions of Nigella sativa on Guinea Pig Tracheal Chains.

OBJECTIVE(S): In regard to the high incidence of asthma and the side-effects of the drugs used, finding novel treatments for this disease is necessary. Our previous studies demonstrated the preventive effect of Nigella sativa extract on ovalbumin-induced asthma. In addition, water-soluble substances of N. sativa extract and methanol fraction of this plant were responsible for the relaxant effect of this plant on tracheal chains of guinea pigs. Therefore, for the first time, in the present study, in order to identify main constituents of the methanolic extract, the relaxant effects of five different methanolic fractions (20%, 40%, 60%, 80%, and 100%) of N. sativa on tracheal chains of guinea pigs were examined. MATERIALS AND METHODS: The relaxant effects of four cumulative concentrations of each fraction (0.8, 1.2, 1.6, and 2.0 g%) in comparison with saline as negative control and four cumulative concentrations of theophylline (0.2, 0.4, 0.6, and 0.8 mM) were examined by their relaxant effects on precontracted tracheal chains of guinea pig by 60 mM KCl (group 1) and 10 µM methacholine (group 2). RESULTS: In group 1, all concentrations of only theophylline showed significant relaxant effects but all concentrations of these methanolic fractions showed significant contractile effects compared with that of saline (P<0.001 to P<0.05). However, in group 2, all concentrations of theophylline and these methanolic fractions showed significant relaxant effects compared with that of saline (P<0.001 to P<0.05). CONCLUSION: These results showed a potent relaxant effect of 20% methanolic fractions from N. sativa on tracheal chains of guinea pigs that were higher than that of theophylline at the used concentrations.

The main relaxant constituents of Nigella sativa methanolic fraction on Guinea pig tracheal chains.

Our previous studies demonstrated the preventive effect of Nigella sativa extract on asthma and water-soluble substances of this extract, especially its methanol fraction were responsible for this relaxation on contracted tracheal chains of guinea pigs. For the first time, the present study has been conducted to determine the main constituents of its methanolic extract. Four constituents of 20%-methanolic fraction, consisting of two flavonoids (20-20% and 21-20% fractions) and two polysaccharides (1-20% and 2-20% fractions), were purified by analytical and preparative HPLC. The relaxant effects of four cumulative concentrations of each constituent (50, 100, 150 and 200 mg/lit) in comparison with saline (1 ml) as negative control and four cumulative concentrations of theophylline (0.2, 0.4, 0.6 and 0.8 mM) as positive control were examined on methacholine-precontracted guinea pig tracheal chains (n=6). All concentrations of theophylline and most concentrations of 20-20, 21-20 fractions showed significant relaxant effects compared to that of saline. 20-20 fraction (Comferol diglucoside) was the most potent bronchodilator. Their relaxant effects were lower than that of theophylline. Polysaccharides (1-20, 2-20 fractions) did not have any relaxant effects compared to that of saline. These results revealed that two flavonoids of 20%-methanolic fraction of Nigella sativa were its main relaxant constituents.