Rolipram and pentoxifylline combination ameliorates the morphological abnormalities of dorsal root ganglion neurons in experimental diabetic neuropathy by reducing mitochondrial dysfunction and apoptosis.

Diabetic neuropathy (DN) is the most prevalent complication of diabetes. Pharmacological treatments for DN are often limited in efficacy, so the development of new agents to alleviate DN is essential. The aim of this study was to evaluate the effects of rolipram, a selective phosphodiesterase-4 inhibitor (PDE-4I), and pentoxifylline, a general PDE inhibitor, using a rat model of DN. In this study, a diabetic rat model was established by i.p. injection of STZ (55 mg/kg). Rats were treated with rolipram (1 mg/kg), pentoxifylline (100 mg/kg), and combination of rolipram (0.5 mg/kg) and pentoxifylline (50 mg/kg), orally for 5 weeks. After treatments, sensory function was assessed by hot plate test. Then rats were anesthetized and dorsal root ganglion (DRG) neurons isolated. Cyclic adenosine monophosphate (cAMP), adenosine triphosphate (ATP, adenosine diphosphate and mitochondrial membrane potential (MMP) levels, Cytochrome c release, Bax, Bcl-2, caspase-3 proteins expression in DRG neurons were assessed by biochemical and ELISA methods, and western blot analysis. DRG neurons were histologically examined using hematoxylin and eosin (H&E) staining method. Rolipram and/or pentoxifylline significantly attenuated sensory dysfunction by modulating nociceptive threshold. Rolipram and/or pentoxifylline treatment dramatically increased the cAMP level, prevented mitochondrial dysfunction, apoptosis and degeneration of DRG neurons, which appears to be mediated by inducing ATP and MMP, improving cytochrome c release, as well as regulating the expression of Bax, Bcl-2, and caspase-3 proteins, and improving morphological abnormalities of DRG neurons. We found maximum effectiveness with rolipram and pentoxifylline combination on mentioned factors. These findings encourage the use of rolipram and pentoxifylline combination as a novel experimental evidence for further clinical investigations in the treatment of DN.

Rolipram and pentoxifylline combination ameliorates experimental diabetic neuropathy through inhibition of oxidative stress and inflammatory pathways in the dorsal root ganglion neurons.

Diabetic neuropathy (DN) is the most challenging microvascular complication of diabetes and there is no suitable treatment for it, so the development of new agents to relieve DN is urgently needed. Since oxidative stress and inflammation play an essential role in the development of DN, clearance of these factors are good strategies for the treatment of this disease. According to key role of cyclic adenosine monophosphate (cAMP) in the regulation of oxidative stress and inflammatory pathways, it seems that phosphodiesterase inhibitors (PDEIs) can be as novel drug targets for improving DN through enhancement of cAMP level. The aim of this study was to evaluate the effects of rolipram, a selective PDE4 inhibitor, and pentoxifylline, a general PDE inhibitor on experimental model of DN and also to determine the possible mechanisms involved in the effectiveness of these agents. We investigated the effects of rolipram (1 mg/kg) and pentoxifylline (100 mg/kg) and also combination of rolipram (0.5 mg/kg) and pentoxifylline (50 mg/kg), orally for five weeks in rats that became diabetic by STZ (55 mg/kg, i.p.). After treatments, motor function was evaluated by open-field test, then rats were anesthetized and dorsal root ganglion (DRG) neurons isolated. Next, oxidative stress biomarkers and inflammatory factors were assessed by biochemical and ELISA methods, and RT-PCR analysis in DRG neurons. Rolipram and/or pentoxifylline treatment significantly attenuated DN - induced motor function deficiency by modulating distance moved and velocity. Rolipram and/or pentoxifylline treatment dramatically increased the cAMP level, as well as suppressed DN - induced oxidative stress which was associated with decrease in LPO and ROS and increase in TAC, total thiol, CAT and SOD in DRG neurons. On the other hand, the level of inflammatory factors (TNF-α, NF-kB and COX2) significantly decreased following rolipram and/or pentoxifylline administration. The maximum effectiveness was with rolipram and/or pentoxifylline combination on mentioned factors. These findings provide novel experimental evidence for further clinical investigations on rolipram and pentoxifylline combination for the treatment of DN.

Bone marrow-mesenchymal stromal cell infusion in patients with chronic kidney disease: A safety study with 18 months of follow-up.

BACKGROUND: Chronic kidney disease (CKD) is a progressive loss of kidney function and structure that affects approximately 13% of the population worldwide. A recent meta-analysis revealed that cell-based therapies improve impaired renal function and structure in preclinical models of CKD. We assessed the safety and tolerability of bone marrow-mesenchymal stromal cell (MSC) infusion in patients with CKD. METHODS: A single-arm study was carried out at one center with 18-month follow-up in seven eligible patients with CKD due to different etiologies such as hypertension, nephrotic syndrome (NS) and unknown etiology. We administered an intravenous infusion (1-2 × 106 cells/kg) of autologous cultured MSCs. The primary endpoint was safety, which was measured by number and severity of adverse events. The secondary endpoint was decrease in the rate of decrease in estimated glomerular filtration rate (eGFR). We compared kidney function during the follow-up visits to baseline and 18 months prior to the intervention. RESULTS: Follow-up visits of all seven patients were completed; however, we have not observed any cell-related adverse events during the trial. Changes in eGFR (P = 0.10) and serum creatinine (P = 0.24) from 18 months before cell infusion to baseline in comparison with baseline to 18 months were not statistically significant. CONCLUSIONS: We showed safety and tolerability of a single-dose infusion of autologous MSCs in patients with CKD.

Acute and Sub-chronic Anticonvulsant Effects of Edaravone on Seizure Induced by Pentylenetetrazole or Electroshock in Mice, Nitric Oxide Involvement.

Background: Edaravone is an anti-stroke medication that may have nitric oxide (NO) modulating properties. This study evaluated the role of NO in the acute and sub-chronic anticonvulsant effects of edaravone in murine models of seizures induced by intraperitoneal (IP) or intravenous (IV) injections of pentylenetetrazole (PTZ) or electroshock (maximal electroshock seizure [MES]). Methods: 132 male albino mice were randomly divided into 22 groups (n=6) and given IP injections of vehicle or edaravone either acutely or for eight days (sub-chronically). The seizure was induced by electroshock or PTZ (IP or IV). The following edaravone doses were used: 7.5, 10, 12.5 (acute); 5, 7.5, 10 (sub-chronic) in IP PTZ model; 5, 7.5, 10 in IV PTZ model; and 5, 10 mg/Kg in the MES. To evaluate NO involvement, 216 mice were randomly divided into 36 groups (n=6) and pretreated with vehicle, edaravone, a non-specific nitric oxide synthase (NOS) inhibitor: N(ω)-nitro-L-arginine methyl ester (L-NAME) (5 mg/Kg), a specific nNOS inhibitor: 7-nitroindazole (7-NI) (60 mg/Kg), or a combination of edaravone plus L-NAME or 7-NI, either acutely or for eight days before seizure induction. Doses of edaravone were as follows: in IP PTZ model: 12.5 (acute) and 10 (sub-chronic); in IV PTZ model: 10; and in the MES: 5 mg/Kg. Data were analyzed using the one-way analysis of variance (ANOVA) followed by Tukey's test (SPSS 18). P≤0.05 was considered statistically significant. Results: In the IP PTZ model, edaravone increased time latencies to seizures (P<0.001), prevented tonic seizures, and death. Edaravone increased the seizure threshold (P<0.001) in the IV PTZ model and shortened the duration of tonic hind-limb extension (THE) in the MES model (P<0.001). In comparison to mice treated with edaravone alone, adding L-NAME or 7-NI reduced seizure time latencies (P<0.001), reduced seizure threshold (P<0.001), and increased THE duration (P<0.001). Conclusion: Edaravone (acute or sub-chronic) could prevent seizures by modulating NO signaling pathways.

The effects of dairy products on seizure tendency in mice.

Epilepsy is a common neurological disorder which occurs as a result of a spontaneous electrical discharge in the brain. According to recent studies there might be a relationship between specific diet and seizure occurrence. Casein is an important protein of milk which often causes hypersensitivity. It seems the release of inflammatory cytokines during the process of immune system response alter the blood-brain-barrier (BBB) integrity and lead to neuronal inflammation which could constitute on epileptogenic focus. On the other hand, several studies represent full-fat milk or higher fat dairy products as an effective anti-inflammatory factor which elevate seizure threshold. The aim of present study was investigation of acute and chronic effects of dairy products including dough (a yogurt-based beverage), cheese, low and high fat yogurt and milk on pentylenetetrazole (PTZ)-induced seizures or electroshock in mice. The results of study indicated that lower fat dairy products reduced seizure threshold in intravenous PTZ-induced seizure as well as reduction in myoclonic and clonic jerk latencies in intraperitoneal PTZ-induced seizure. High fat products or cheese reduced seizure activity in both PTZ-induced models. Meanwhile both acute and chronic administration of dairy products had no effect on an electroshock-induced seizure. Therefore, diet-related seizures may depend upon the method which seizures are provoked.

Sub-chronic boldine treatment exerts anticonvulsant effects in mice.

OBJECTIVES: Boldine is an aporphine alkaloid which is best known for its antioxidant, anti-inflammatory and cytoprotective characteristics. It seems that all these activities are related to boldine ability to scavenge reactive free radicals. As indicated by several pieces of evidence, free radicals generation are involved in initiation and propagation of epilepsy. METHODS: In this study, we investigated the sub-chronic effects of boldine on intraperitoneal and intravenous pentylenetetrazole (PTZ) models and electroshock-induced seizure in mice. Mice in treatment groups received different doses of boldine (once in a day for 8 days, ip.) and control group received solvent. We also evaluated the role of antioxidant activity of boldine as a part of its anti-seizure activity. RESULTS: The results demonstrated that sub-chronic administration of boldine increased time latencies to the onset of myoclonic and clonic seizure induced by intraperitoneal PTZ model and increased clonic seizure threshold in intravenous PTZ model. It also decreased tonic hind limb extension duration in the electroshock-induced seizure model. Co-administration of boldine with a non-effective dose of vitamin C induced the anticonvulsant activity of vitamin C. Superoxide dismutase (SOD) activity in the brain tissue of animals was increased following sub-chronic administration of boldine which all indicated antioxidant activity of boldine may be a part of its anticonvulsant activity. DISCUSSION: The anticonvulsant effects of boldine in three different animal models of epilepsy have been indicated. We have also shown that the antioxidant role of boldine might be a part of its anticonvulsant effect.

Acute and chronic effects of agomelatine on intravenous penthylenetetrazol-induced seizure in mice and the probable role of nitric oxide.

Agomelatine is a potent MT1 and MT2 melatonin receptor agonist as well as a 5-HT2C serotonin receptor antagonist. It was approved by the European Medicines Agency as an antidepressant drug in year 2009. On the other hand, the involvement of melatonin and serotonin receptors in the modulation of seizure threshold has been demonstrated previously. The purpose of this study was to investigate the effect of agomelatine on penthylenetetrazol-induced seizure threshold in male mice. Therefore, we evaluated the effect of acute (12.5, 25, 50, 75 and 100 mg/kg, p.o. and chronic (25, 50 and 75 mg/kg, p.o., once a day, for 7 days) agomelatine administration on mouse model of intravenous penthylenetetrazol-induced seizure. For evaluation of nitrergic system involvement in the anticonvulsant effect of agomelatine, co-administration of multiple nitric oxide synthase (NOS) inhibitors [L-NAME, a non-selective NOS inhibitor, (5 mg/kg, p.o.), aminoguanidine, a selective iNOS inhibitor, (100 mg/kg, p.o.) or 7-nitroindazol, a selective nNOS inhibitor, (60 mg/kg, p.o.)] and agomelatine (50 and 75 mg/kg) were examined. In acute study, agomelatine (50 and 75 mg/kg) increased clonic seizure threshold compared to control group (P<0.05 and 0.01, respectively). In chronic study, agomelatine had no effect on clonic seizure threshold compared with control mice. Co-administration of L-NAME, aminoguanidine or 7-nitroindazol with agomelatine (50 and 75 mg/kg) prevented a agomelatine-induced anti-convulsant effect. Our results suggest that agomelatine has anticonvulsant activity in intravenous penthylenetetrazol-induced seizure in acute therapy and this effect can be at least in part due to iNOS or nNOS induction.