Ameliorative effect of bone marrow-derived mesenchymal stem cells on burn-induced hepatic and metabolic derangements in rats.

AIMS: The current study aims to investigate the therapeutic potential of bone marrow-derived mesenchymal stem cells (MSCs) as a solo therapy in ameliorating both skin lesions and liver injury induced by cutaneous severe burn injury (SBI) in rats. MAIN METHODS: In anesthetized male adult Wistar albino rats, 30 % total burn surface area and established hepatic injury was achieved via direct contact of each experimental animal's dorsum with heated metal rod (100 °C) for 10 s. On the next day following burn, human MSCs or mouse MSCs was administered locally around the burn site and intraperitonially (0.5 × 106 cells/rat for each route) and outcomes were investigated at 4 and 14 days following burn induction. KEY FINDINGS: Both types of MSCs significantly improved skin and liver histology, decreased liver enzymes, and ameliorated oxidative stress in hepatocytes of SBI-rats. Further, SBI-induced rises in hepatic apoptotic marker (caspase-3, Bax) and serum inflammatory markers (TNF-α, IL-1ß, and IL-6) were reduced following either human or mouse MSC administration. In addition, MSCs augmented insulin receptor substrate-1, phosphorylated protein kinase-B (phospho-Akt), while alleviating serum glucose levels in SBI-rats. These previous effects persisted even at the 14-day time point. SIGNIFICANCE: Following single administration, bone marrow-derived MSCs is capable of counteracting SBI-induced skin lesions as well as related hepatic complications, specifically via mitigating postburn hyperglycemia and hyperinflammation.

Vitamin D3 potentiates the nephroprotective effects of vildagliptin-metformin combination in a rat model of metabolic syndrome.

The current study was conducted to investigate the nephroprotective effects of vildagliptin-metformin combination in an experimental model of fructose/salt-induced metabolic syndrome (MetS). A major aim was to evaluate the potential capacity of vitamin D3 to potentiate the pleiotropic nephroprotective effects of vildagliptin-metformin combination. MetS was induced in adult male Wistar rats by adding fructose (10%) to everyday drinking water and salt (3%) to the diet for 6 weeks. Along with the same concentrations of fructose/salt feeding, MetS rats were then treated orally with either vildagliptin (10 mg/kg/day)-metformin (200 mg/kg/day) combination, vitamin D3 (10 µg/kg/day), or the triple therapy for a further 6 weeks. The incidence of MetS was confirmed 6 weeks after fructose/salt consumption, when the rats exhibited significant weight gain, dyslipidemia, hyperuricemia, insulin resistance, hyperinsulinemia, and impaired glucose tolerance. At the end of the 12-week experimental period, MetS rats displayed significantly deteriorated renal function, enhanced intrarenal oxidative stress and inflammation together with exaggerated renal histopathological damages and interstitial fibrosis. The study has corroborated antioxidant, anti-inflammatory, and antifibrotic effects of vildagliptin-metformin combination, vitamin D3, and the triple collaborative therapy, conferring renoprotection in the setting of MetS. Due attention has been paid to the crucial role of dipeptidyl peptidase-4 inhibition and sirtuin-1/5' adenosine monophosphate-activated protein kinase activation as novel therapeutic targets to optimize renoprotection. The apparent potentiating effect, evoked upon coadministration of vitamin D3 with vildagliptin-metformin combination, may provide a cornerstone for further clinical investigations.

Renoprotective effects of vitamin D3 supplementation in a rat model of metabolic syndrome.

PURPOSE: The study aimed to investigate the potential nephroprotective effects of vitamin D3 in metabolic syndrome (MetS) and the molecular basis of the underlying mechanisms of its action. METHODS: MetS was induced in adult male Wistar rat s by adding fructose (10%) to every day drinking water and salt (3%) to the diet. Six weeks after fructose/salt consumption, fasting serum lipid profile and uric acid levels were determined, an oral glucose tolerance test (OGTT) was performed and kidney function was checked. MetS rats were then treated orally with vitamin D3 (10 µg/kg/day) for 6 weeks. At the end of the study period (12 weeks), the OGTT test was reperformed, anthropometrical parameters were measured, urine, blood and tissue samples were collected and the animals were euthanised. RESULTS: The incidence of MetS was confirmed 6 weeks after fructose/salt consumption, when the rats exhibited significant weight gain, dyslipidemia, hyperuricemia, insulin resistance, hyperinsulinemia and impaired glucose tolerance. After 12 weeks, MetS rats displayed markedly declined renal function alongside with extravagant renal histopathological damages and interstitial fibrosis. Furthermore, significantly enhanced renal oxidative stress and inflammation were manifested. Vitamin D3 supplementation in MetS rats significantly reversed all the above-mentioned deleterious effects. CONCLUSION: The study has indeed provided mounting evidence of the promising therapeutic potential of vitamin D3 against development and progression of MetS-induced nephropathy. A new insight has been introduced into the crucial role of dipeptidyl peptidase-4 inhibition and sirtuin-1/5'adenosine monophosphate-activated protein kinase activation in the renoprotective effects of vitamin D3.

Vitamin D3 potentiates the nephroprotective effects of metformin in a rat model of metabolic syndrome: role of AMPK/SIRT1 activation and DPP-4 inhibition.

The current study aimed to investigate the molecular mechanisms of metformin and vitamin D3-induced nephroprotection in a metabolic syndrome (MetS) rat model, evaluating the capacity of vitamin D3 to potentiate metformin action. MetS was induced by 10% fructose in drinking water and 3% salt in the diet. After 6 weeks, serum lipid profile and uric acid were measured, an oral glucose tolerance test (OGTT) was performed, and kidney function was investigated. In conjunction with the same concentrations of fructose and salt feeding, MetS rats with significant weight gain, dyslipidemia, hyperuricemia, and dysglycemia were treated orally with metformin (200 mg/kg), vitamin D3 (10 µg/kg), or both daily for 6 weeks. At the end of the study period, anthropometrical parameters were recorded, OGTT was reperformed, urine and blood samples were collected, and tissue samples were harvested at sacrifice. MetS rats showed dramatically declined renal function, enhanced intrarenal oxidative stress and inflammation, and extravagant renal histopathological damage with interstitial fibrosis. Metformin and vitamin D3 significantly reversed all the aforementioned deleterious effects in MetS rats. The study has verified the nephroprotective effects of metformin and vitamin D3 in MetS, accentuating the critical role of AMP-activated protein kinase/sirtuin-1 activation and dipeptidyl peptidase-4 inhibition. Given the synergistic effects of the combination, vitamin D3 is worth being investigated as an additional therapeutic agent for preventing MetS-induced nephropathy.

Vitamin D3 potentiates the renoprotective effects of vildagliptin in a rat model of fructose/salt-induced insulin resistance.

Insulin resistance (IR) seemingly plays a role in chronic kidney disease (CKD). The present study has elucidated the crucial interplay of oxidative stress, inflammatory, apoptotic and profibrotic signaling pathways, linking IR to CKD. The study aimed at investigating the pleiotropic nephroprotective effects of either vildagliptin or vitamin D3 in a fructose/salt-induced IR rat model, highlighting the potential molecular mechanisms underlying their action. Another interesting target was to evaluate the potential capacity of vitamin D3 to potentiate the nephroprotective effects of vildagliptin. Indeed, a state of impaired fasting glucose, IR and compensatory hyperinsulinemia, constellating with significant weight gain, atherogenic dyslipidemia and hyperuricemia was established 6 weeks after fructose/salt consumption. IR rats were then treated orally with vildagliptin (10 mg/kg/day), vitamin D3 (10 µg/kg/day) or their combination for a further 6 weeks. By the end of the 12th week, untreated IR rats displayed significantly declined renal function with parallel interwined renal oxidative stress, inflammatory, apoptotic and profibrotic changes, renal histopathological damages and markedly enhanced collagen fiber deposition. Vildagliptin and vitamin D3 reversed hyperuricemia and exerted a plethora of renal anti-oxidant, anti-inflammatory, anti-apoptotic and anti-fibrotic effects. Our study has introduced a new insight into the role of dipeptidyl peptidase-4 inhibition and silent information regulator 1/5'adenosine monophosphate-activated protein kinase activation in the nephroprotective effects of either agent, elucidating their possible crosstalk with renin angiotensin aldosterone system downregulation. Considering the superadditive renoprotective effects evoked by the combination, vitamin D3 is worth being further investigated as an additional therapeutic agent for preventing IR-induced nephropathy.

Development and Validation of Two Robust Stability-Indicating Chromatographic Methods for Determination of Metolazone in Drug Substance and Pharmaceutical Dosage Form in the Presence of Its Degradation Products and Characterization of Main Degradation Products Based on LC-MS.

Two robust and selective stability-indicating chromatographic methods were developed and validated for the determination of metolazone in drug substance and pharmaceutical dosage form in the presence of its degradation products. The HPLC method employed a Kromasil C18 (250 × 4.6,5 µm) column and a mobile phase of acetonitrile: 0.2% orthophosphoric acid (32:68 v/v) at a flow rate 2 mL/min and detection at 238 nm. The separation was performed in HPLC isocratic mode. The robustness of the suggested method was assessed using the Plackett-Burman design, parameters affecting system suitability were established and non-significant intervals for the significant parameters were considered. The HPTLC method employed Nano-SIL-20 UV254 HPTLC plates as adsorbent, ethyl acetate: toluene: acetic acid solution (4:4:0.5, v/v/v), as a developing solvent system and densitometric detection at 238 nm. Metolazone was exposed to different stress conditions, including acid and alkaline hydrolysis and oxidative and photolytic degradation. The main degradation products obtained have been characterized and interpreted based on LC-MS. The linearity of the suggested methods was proved in the concentration range of 20-75 µg/mL for the HPLC method and 100-900 ng/spot for the HPTLC method. The suggested methods were validated according to international conference on harmonization guidelines. These methods were successfully dedicated for the estimation of metolazone in drug substance and pharmaceutical dosage form in the presence of its degradation products. The results of the suggested methods were evaluated and compared statistically with results obtained by an official method without finding any significant difference.

Impact of Exposure to Fenitrothion on Vital Organs in Rats.

This study was designed to investigate the impact of oral administration of fenitrothion (10 mg/kg) on liver, kidney, brain, and lung function in rats. The effect was studied on days 7, 14, 21, 28, and 42. Our results have shown deterioration in liver function as evidenced by the elevation in serum ALT, AST, ALP, and bilirubin and reduction in albumin and hepatic glycogen. This was associated with a state of hyperglycemia and hyperlipidemia and increased prothrombin time, while hemoglobin content was reduced. In addition, the kidney function was reduced as indicated by the elevation in serum creatinine, uric acid, and BUN, while the serum levels of magnesium, potassium, and sodium were reduced. This study also showed an impairment in brain neurotransmitter (elevated 5-HT, glutamate, GABA, and reduced dopamine and norepinephrine level). This was associated with a reduction in the barrier capacity in brain and lung. Fenitrothion also caused a decrease in cholinesterase activity in serum, lung, and brain activity associated with a state of oxidative stress in all tested organs and hyperammonemia. These results support the hazards of pesticide use and shows the importance of minimizing pesticide use or discovering new safe pesticides.

Cystathionine-γ lyase-derived hydrogen sulfide mediates the cardiovascular protective effects of moxonidine in diabetic rats.

Blunted cystathionine-γ lyase (CSE) activity (reduced endogenous H2S-level) is implicated in hypertension and myocardial dysfunction in diabetes. Here, we tested the hypothesis that CSE derived H2S mediates the cardiovascular protection conferred by the imidazoline I1 receptor agonist moxonidine in a diabetic rat model. We utilized streptozotocin (STZ; 55mg/kg i.p) to induce diabetes in male Wistar rats. Four weeks later, STZ-treated rats received vehicle, moxonidine (2 or 6mg/kg; gavage), CSE inhibitor DL-propargylglycine, (37.5mg/kg i.p) or DL-propargylglycine with moxonidine (6mg/kg) for 3 weeks. Moxonidine improved the glycemic state, and reversed myocardial hypertrophy, hypertension and baroreflex dysfunction in STZ-treated rats. Ex vivo studies revealed that STZ caused reductions in CSE expression/activity, H2S and nitric oxide (NO) levels and serum adiponectin and elevations in myocardial imidazoline I1 receptor expression, p38 and extracellular signal-regulated kinase, ERK1/2, phosphorylation and lipid peroxidation (expressed as malondialdehyde). Moxonidine reversed these biochemical responses, and suppressed the expression of death associated protein kinase-3. Finally, pharmacologic CSE inhibition (DL-propargylglycine) abrogated the favorable cardiovascular, glycemic and biochemical responses elicited by moxonidine. These findings present the first evidence for a mechanistic role for CSE derived H2S in the glycemic control and in the favorable cardiovascular effects conferred by imidazoline I1 receptor activation (moxonidine) in a diabetic rat model.

Nalbuphine could decrease the rewarding effect induced by tramadol in mice while enhancing its antinociceptive activity.

Nalbuphine, a kappa-opioid agonist and mu-opioid partial agonist, has been used as an analgesic or an adjuvant with morphine to attenuate the development of morphine dependence and rewarding effect. In this study, we investigated the effect of nalbuphine on tramadol rewarding effect and antinociception. Using the conditioned place preference (CPP) paradigm in mice, we demonstrated that co-administration of nalbuphine (7mg/kg, s.c.) with tramadol (70mg/kg, s.c.) during conditioning completely blocked the CPP induced by tramadol. Co-administration of nalbuphine blocked the increase in dopamine level in the nucleus accumbens induced by tramadol. These actions were accompanied by an increase rather than attenuation of the antinociceptive effect of tramadol. These results suggest that nalbuphine could have a great potential as a pharmacotherapy for tramadol abuse.

BLOCKADE OF PGE2, PGD2 RECEPTORS CONFERS PROTECTION AGAINST PREPATENT SCHISTOSOMIASIS MANSONI IN MICE.

Schistosomiasis is a chronic disease with considerable social impact. Despite the availability of affordable chemotherapy, drug treatment has not significantly reduced the overall number of disease cases. Among other mechanisms, the parasite produces PGE2 and PGD2 to evade host immune defenses. To investigate the role of PGE2 and PGD2 in schistosomiasis, we evaluated the effects of L-161,982, Ah6809 (PGE2 receptor antagonists alone of combined with each other) and MK-0524 (PGD2 receptor antagonist) during prepatent Schistosoma mansoni infection. Drugs were administered intraperitoneally an hour before and 24 hours after infection of C57BL/6 mice with 100 Schistosoma mansoni cercariae. L-161,982, Ah6809, their combination and MK-0524 caused partial protection against pre-patent S. mansoni infection which was mediated by biasing the immune response towards Th1 phenotype. These results showed that blockade of PGE2 and PGD2 receptors confers partial protection against pre-patent S. mansoni infection in mice and that they may be useful as adjunctive therapy to current anti-schistosomal drugs or vaccines.