Methoxy VO-salen stimulates pancreatic β cell survival by upregulation of eNOS and downregulation of apoptosis in STZ-induced diabetic rats

Vanadium and diabetic dyslipidemia: A systematic review of animal studies

BACKGROUND

Diabetic dyslipidemia is caused by hyperglycemia and excessive mobilization of storage lipids, leading to increasing concentrations of triglycerides and total cholesterol. Due to the insulin-mimetic or insulin-enhancer features of vanadium, it has been recognized as a regulator of cell metabolism with hypoglycemic and hypolipidemic properties. The purpose of the current animal systematic review was to evaluate the effect of vanadium administration on diabetic dyslipidemia in diabetic animals.

METHODS

This is, to our knowledge, the first systematic review with the aim of investigating the relationship between vanadium and diabetic dyslipidemia among diabetes induced animals. Searches were performed in PubMed, Scopus, and web of science databases for animal studies examining the effect of vanadium on diabetic dyslipidemia in diabetic animals.

RESULTS

Of 124 full-text articles assessed, 48 animal studies were included in the present study with minor risk of bias. The majority of the studies confirmed the beneficial effects of different vanadium compounds in at least one of the parameters of lipid profile, especially regarding triglyceride and total cholesterol.

CONCLUSION

Current findings lend support to assess the long-term effects of different forms and doses of vanadium on lipid profile through well-designed clinical trials.

Date palm fruit extract ameliorated pancreatic apoptosis, endocrine dysfunction and regulatory inflammatory cytokines in Streptozotocin-induced diabetes in rats

The current work studied the mechanism(s) and ability by which date palm (Phoenix dactylifera L.) fruit extract (DPE) inspired a glucose-lowering impact in rats suffering from diabetes. Forty-eight albino rats were divided into six various experimental treatments after induction of diabetes by intraperitoneal infusion of streptozotocin (45 mg/kg bwt) as follows: normal control, DPE, diabetic control, diabetic glibenclamide (GLI), diabetic DPE, and diabetic GLI plus DPE-treated groups. In animals euthanized after 8 weeks, blood and pancreatic tissue samples were assembled to assess different biochemical and histopathological changes. The expressions of insulin, B cell lymphoma-2 (Bcl-2), and cysteine aspartate-specific protease-3 (caspase-3) in islet β cells were also evaluated using immunohistochemical assessment. Diabetic rats exhibited hyperglycemia; increment of pancreatic malondialdehyde (lipid peroxidation biomarker), tumor necrosis factor-α (TNF-α), and interleukin-1β (IL-1β); and decrement of plasma insulin and pancreatic antioxidants: glutathione, superoxide dismutase, and catalase values. Also, the pancreatic islets exhibited histopathological and morphometric alternations associated with weak positive insulin and Bcl-2 immunoreactivity and strong positive caspase-3 immunoreactivity. DPE and/or GLI, an anti-diabetic drug, improved the pancreatic histoarchitecture and improved β cell function and structure, which increased insulin levels and improved the insulin, Bcl-2, and caspase-3 immunoreactivity in diabetic rats. Nevertheless, the combined DPE and GLI therapy revealed a significant recovery and restoration of β cells' structure and function. The date palm fruit has anti-apoptotic, anti-inflammatory, and antioxidant activities and hypoglycemic effects, which in turn play a pivotal role in avoiding the progression of diabetes mellitus. Moreover, it could potentiate the glucose-lowering activity of anti-diabetic drugs.

Treatment effect of l-Norvaline on the sexual performance of male rats with streptozotocin induced diabetes

Sexual impairment is an established risk factor in diabetes mellitus affecting about 75% of male diabetic population. In diabetes overexpression of arginase leads to decreased production of NO and diminished erectile response. Inhibition of arginase enzyme can lead to improvement in diabetes induced sexual dysfunction. In the present study diabetes mellitus was induced in adult male rats by intraperitoneal injection of single dose of streptozotocin (65mg/kg) in 0.1M Citrate buffer pH 4.5 and after 72h fasting serum glucose level was checked by glucose oxidase-peroxidase method and those animals showing FSG above 250mg/dl were selected. Diabetic animals were divided into four groups comprising six animals in each. l-Norvaline, potent arginase inhibitor was administered at a dose of 10mg/kg ip to the different groups of diabetic animals for a period of 30 days. Sildenafil at a dose of 5mg/kg orally was used as a standard drug. Mating behavior tests were performed at 0, 15th and 30th days. After 30 days, various biochemical and hormonal parameters (nitrates, LDH, urea, testosterone), testicular parameters (total protein, nitrates, LDH, total cholesterol, LDL, triglycerides, VLDL, HDL) were evaluated to find out the effect of l-Norvaline in sexual impairment. Sperm analysis was also carried out for the treated rats. l-Norvaline showed significant improvement in serum nitrates, urea, LDH, testosterone and testicular protein level as compared with diabetic group. It also improved sperm motility, count and viability in diabetic rats. Sildenafil showed no improvement in above parameters except restoration in serum nitrates level.

A novel role for carbon monoxide as a potent regulator of intracellular Ca2+and nitric oxide in rat pancreatic acinar cells

Carbon monoxide (CO) is known as an essential gaseous messenger that regulates a wide array of physiological and pathological processes, similar to nitric oxide (NO) and hydrogen sulfide. The aim of the present study was to elucidate the potential role of CO in Ca2+homeostasis and to explore the underlying mechanisms in pancreatic acinar cells. The exogenous application of a CO-releasing molecule dose-dependently increased intracellular Ca2+concentration ([Ca2+]i). A heme oxygenase (HO) inducer increased [Ca2+]iin a concentration-dependent manner, and the increase was diminished by an HO inhibitor. The CO-induced [Ca2+]iincrease persisted in the absence of extracellular Ca2+, indicating that Ca2+release is the initial source for the increase. The inhibition of G protein, phospholipase C (PLC), and inositol 1,4,5-trisphosphate (IP3) receptor diminished the CO-induced [Ca2+]iincrease. CO upregulated endothelial nitric oxide synthase (eNOS) expression and stimulated NO production, and NOS inhibitor, calmodulin inhibitor, or the absence of extracellular Ca2+eliminated the latter response. Blocking the phosphatidylinositol 3-kinase (PI3K)-Akt/protein kinase B (PKB) pathway abolished CO-induced NO production. Pretreatment with an NOS inhibitor, NO scavenger, or soluble guanylate cyclase inhibitor, did not affect the CO-induced [Ca2+]iincrease, indicating that NO, soluble guanylate cyclase, and cyclic guanosine 5′-monophosphate are not involved in the CO-induced [Ca2+]iincrease. CO inhibited the secretory responses to CCK-octapeptide or carbachol. We conclude that CO acts as a regulator not only for [Ca2+]ihomeostasis via a PLC-IP3-IP3receptor cascade but also for NO production via the calmodulin and PI3K-Akt/PKB pathway, and both CO and NO interact. Moreover, CO may provide potential therapy to ameliorate acute pancreatitis by inhibiting amylase secretion.

Assemblies of salen-type oxidovanadium(iv) complexes: substituent effects and in vitro protein tyrosine phosphatase inhibition

A systematic study of 5,5′-disubstituted oxidovanadium(iv) complexes with a chiral salen type ligand showed variable assemblies of complex molecules dependent on steric and electronic factors of the substituents.

Treatment with ferulic acid to rats with streptozotocin-induced diabetes: effects on oxidative stress, pro-inflammatory cytokines, and apoptosis in the pancreatic β cell

In the present study, we aimed to investigate the protective effect of ferulic acid at different doses (50 mg/kg alternative day and 50 mg/kg daily) on diabetic rats and to explore the interrelationship between oxidative stress and cytokines correlates with apoptotic events in pancreatic tissue. Male Wistar rats were rendered diabetic by a single intraperitoneal injection of streptozotocin (60 mg/kg body weight). Ferulic acid was administered orally for 8 weeks. At the end of the study, all animals were sacrificed. Blood samples were collected for the biochemical estimations and pancreas was isolated for antioxidant status, histopathological, immunohistochemical, and apoptotic studies. Treatment with ferulic acid to diabetic rats significantly improved blood glucose, serum total cholesterol, triglycerides, creatinine, urea, and albumin levels toward normal. Furthermore, decrement of the elevated lipid peroxidation levels and increment of the reduced superoxide dismutase, catalase, and reduced glutathione enzyme activities in pancreatic tissues were observed in ferulic acid-treated groups. Ferulic acid-treated rats in the diabetic group showed an improved histological appearance. Our data also revealed a significant reduction in the activity of apoptosis using terminal dUTP nick end-labeling and reduced expression of TGF-β1 and IL-1β in the pancreatic β-cell of ferulic acid-treated rats. Treatment with ferulic acid daily doses produced a significant result compared to alternative dose. Collectively our results suggested that ferulic acid acts as a protective agent in diabetic rats by altering oxidative stress, expression of pro-inflammatory cytokines and apoptosis.