vitamin-b-12 and Reperfusion-Injury

Cerebral ischemia-reperfusion injury (CIRI) is often accompanied by upregulation of homocysteine (Hcy). Excessive Hcy damages cerebral vascular endothelial cells and neurons, inducing neurotoxicity and even neurodegeneration. Normally, supplementation of vitamin B

Topics: Animals; Brain Ischemia; Endothelial Cells; Homocysteine; Lysosomes; Malondialdehyde; Mice; Reperfusion Injury; Vitamin B 12; Vitamins

Ovarian ischemia is a gynecological emergency case that occurs as a result of ovarian torsion. Oxidative stress and inflammation play central roles in the development of ischemia/reperfusion injuries. We investigated the effects of Vitamin B12, thought to possess antioxidant characteristics on oxidative stress and the toll-like receptor 4 (TLR-4)/nuclear factorkappa B (NF-κB) signaling pathway in the ovaries during ischemia-reperfusion. Forty-eight rats were randomly assigned into six groups and the groups are designed as follows: Control (C), Ischemia (I), Ischemia + Vitamin B12 (I + B12), Ischemia-Reperfusion (I/R), I/R + Vitamin B12 (I/R + B12) and Sham + Vitamin B12. Vitamin B12 was administered at a dose of 400 mcg/kg via the i.p. route once daily for three days before I/R procedure. Tissue interleukin-1β (IL-1β) and interleukin-6 (IL-6) and malondialdehyde (MDA) levels in ovarian tissue increased following I/R, while glutathione (GSH) levels decreased. Moreover, extensive congestion, edema, hemorrhage and defective follicle were observed. Both NF-κB and TLR-4 expression levels also increased in the group exposed to I/R. While GSH levels increased, IL-1β, IL-6, MDA, NF-κB and TLR-4 levels decreased with Vitamin B12 treatment. In addition, ovarian tissue without edema, mild congestion, and normal-appearing follicles were observed following Vitamin B12 administration. The findings showed that I/R in ovarian tissue resulted in significant tissue damage by increasing oxidative stress and inflammation. However, Vitamin B12 application was effective and alternative agent in reducing injury deriving from inflammation and oxidative stress developing in association with I/R in ovarian tissue.

Topics: Animals; Female; Glutathione; Inflammation; Interleukin-6; Ischemia; NF-kappa B; Ovary; Oxidative Stress; Rats; Rats, Wistar; Reperfusion Injury; Signal Transduction; Toll-Like Receptor 4; Vitamin B 12

We investigated the histopathological and biochemical effects of vitamin B12 on ischemia-reperfusion (I-R) injury using a rat ovarian torsion-detorsion model. We used four groups of female Wistar albino rats. Group 1 (sham group): both ovaries were removed. Group 2 (torsion group): ovarian torsion was established. Group 3 (torsion-detorsion group) perfusion was retored after ischemia for 2 h. Group 4 (torsion-detorsion-vitamin B12 group): after 2 h ovarian torsion, perfusion was re-established and 4 mg/kg vitamin B12 was administered for 2 h. Follicular degeneration, vascular congestion, hemorrhage, edema and infiltration were evaluated histologically. Tissue damage was decreased in group 4 compared to groups 2 and 3. Total antioxidant status TAS), total oxidant status (TOS) and malondialdehyde (MDA) level were measured. The values for TOS and MDA for groups 1 and 4 were similar. We found a significant increase in MDA and TOS levels in group 3 compared to group 2. MDA and TAS levels decreased and TOS levels were increased in group 4 compared to groups 2 and 3. MDA, TAS and TOS values were increased in groups 2 and 3 compared to group 1. We found that vitamin B12 reduced I-R damage in the rat ovary.

Topics: Animals; Antioxidants; Female; Malondialdehyde; Ovary; Rats; Rats, Wistar; Reperfusion Injury; Vitamin B 12

Despite advances in the understanding of the pathophysiology of ischemic stroke, therapeutic options remain limited. Methylcobalamin is an endogenous vitamin B12 that exhibits anti-inflammatory and antiapoptotic activities in a variety of diseases. In this study, we aimed to explore the neuroprotective effects and mechanism of action of methylcobalamin on cerebral ischemic injury in vitro and in vivo. The oxygen and glucose deprivation/reperfusion model and middle cerebral artery occlusion model were used to simulate cerebral ischemic injury in vitro and in vivo. Cell viability, inflammatory factors, cell apoptosis, and protein expression levels were determined. Further, autophagy flux and the cerebral infarction volume were measured. The modified neurological severity score, Longa score, Rotarod assay, and foot-fault test were used to evaluate behavioral changes and neurological deficits in rats. In vitro, methylcobalamin significantly increased cell viability, decreased lactate dehydrogenase release, attenuated inflammatory cytokine expression, reduced the apoptotic proportion, and enhanced autophagy flux after OGD treatment. In addition, Bcl-2 and Beclin1 expression levels and the LC3 II/I ratio were increased, whereas levels of Bax and cleaved caspase-3 were decreased. In vivo, methylcobalamin significantly reduced the cerebral infarction volume and neurological deficits in the rats. Furthermore, methylcobalamin activated the ERK1/2 pathway, whereas ERK1/2 inhibitors diminished its effects in the in vitro and in vivo models. In conclusion, methylcobalamin may exert a neuroprotective effect on cerebral ischemia and is a promising drug candidate for developing novel neuroprotective therapies.

Topics: Animals; Apoptosis; Autophagy; Brain Ischemia; Cell Line; Cell Survival; Cytokines; Disease Models, Animal; Infarction, Middle Cerebral Artery; Male; MAP Kinase Signaling System; Mitogen-Activated Protein Kinase 1; Mitogen-Activated Protein Kinase 3; Neuroprotective Agents; Protein Kinase Inhibitors; Rats; Rats, Sprague-Dawley; Reperfusion Injury; Vitamin B 12

Renal ischemia/reperfusion injury (IRI) is a leading cause of acute kidney injury (AKI), a potentially fatal syndrome characterized by a rapid decline in kidney function. Excess production of superoxide contributes to the injury. We hypothesized that oral administration of a high dose of vitamin B12 (B12 - cyanocobalamin), which possesses a superoxide scavenging function, would protect kidneys against IRI and provide a safe means of treatment. Following unilateral renal IR surgery, C57BL/6J wild type (WT) mice were administered B12 via drinking water at a dose of 50 mg/L. After 5 days of the treatment, plasma B12 levels increased by 1.2-1.5x, and kidney B12 levels increased by 7-8x. IRI mice treated with B12 showed near normal renal function and morphology. Further, IRI-induced changes in RNA and protein markers of inflammation, fibrosis, apoptosis, and DNA damage response (DDR) were significantly attenuated by at least 50% compared to those in untreated mice. Moreover, the presence of B12 at 0.3 μM in the culture medium of mouse proximal tubular cells subjected to 3 hr of hypoxia followed by 1 hr of reperfusion in vitro showed similar protective effects, including increased cell viability and decreased reactive oxygen species (ROS) level. We conclude that a high dose of B12 protects against perfusion injury both in vivo and in vitro without observable adverse effects in mice and suggest that B12 merits evaluation as a treatment for I/R-mediated AKI in humans.

Topics: Acute Kidney Injury; Animals; Apoptosis; Ischemia; Kidney; Mice; Mice, Inbred C57BL; Reperfusion Injury; Superoxides; Vitamin B 12

Hyperhomocysteinemia (HHcy) is a well-known risk factor for stroke; however, its underlying molecular mechanism remains unclear. Using both mouse and cell culture models, we have provided evidence that impairment of autophagy has a central role in HHcy-induced cellular injury in the mouse brain. We observed accumulation of LC3B-II and p62 that was associated with increased MTOR signaling in human and mouse primary astrocyte cell cultures as well as a diet-induced mouse model of HHcy, HHcy decreased lysosomal membrane protein LAMP2, vacuolar ATPase (ATP6V0A2), and protease cathepsin D, suggesting that lysosomal dysfunction also contributed to the autophagic defect. Moreover, HHcy increased unfolded protein response. Interestingly, Vitamin B supplementation restored autophagic flux, alleviated ER stress, and reversed lysosomal dysfunction due to HHCy. Furthermore, the autophagy inducer, rapamycin was able to relieve ER stress and reverse lysosomal dysfunction caused by HHcy in vitro. Inhibition of autophagy by HHcy exacerbated cellular injury during oxygen and glucose deprivation and reperfusion (OGD/R), and oxidative stress. These effects were prevented by Vitamin B co-treatment, suggesting that it may be helpful in relieving detrimental effects of HHcy in ischemia/reperfusion or oxidative stress. Collectively, these findings show that Vitamin B therapy can reverse defects in cellular autophagy and ER stress due to HHcy; and thus may be a potential treatment to reduce ischemic damage caused by stroke in patients with HHcy.

Topics: Animals; Astrocytes; Autophagy; Cell Line, Tumor; Cell Survival; Cells, Cultured; Diet; Dietary Supplements; Endoplasmic Reticulum Stress; Folic Acid; Glucose; Humans; Hyperhomocysteinemia; Lysosomes; Male; Mice; Mice, Inbred C57BL; Microtubule-Associated Proteins; Models, Biological; Oxidative Stress; Oxygen; Reperfusion Injury; Sequestosome-1 Protein; TOR Serine-Threonine Kinases; Vitamin B 12

Cyanocobalamin (B(12)) offers a biocompatible scaffold for CO-releasing 17-electron dicarbonyl complexes based on the cis-trans-[Re(II)(CO)(2)Br(2)](0) core. A Co-C≡N-Re conjugate is produced in a short time and high yield from the reaction of [Et(4)N](2)[Re(II)Br(4)(CO)(2)] (ReCORM-1) with B(12). The B(12)-Re(II)(CO)(2) derivatives show a number of features which make them pharmaceutically acceptable CO-releasing molecules (CORMs). These cobalamin conjugates are characterized by an improved stability in aqueous aerobic media over the metal complex alone, and afford effective therapeutic protection against ischemia-reperfusion injury in cultured cardiomyocytes. The non-toxicity (at μM concentrations) of the resulting metal fragment after CO release is attributed to the oxidation of the metal and formation in solution of the ReO(4)(-) anion, which is among the least toxic of all of the rare inorganic compounds. Theoretical and experimental studies aimed at elucidating the aqueous chemistry of ReCORM-1 are also described.

Topics: Animals; Animals, Newborn; Carbon Monoxide; Cell Survival; Cells, Cultured; Cytoprotection; Drug Design; Drug Stability; Models, Molecular; Molecular Structure; Myocytes, Cardiac; Organometallic Compounds; Oxidative Stress; Rats; Reperfusion Injury; Rhenium; Vitamin B 12

In the liver, eNOS appears to have a central role in protecting against ischemia/reperfusion (I/R) injury. We hypothesized that tetrahydrobiopterin (BH4) would protect livers subjected to I/R injury by coupling with eNOS.. Chinese Kun Ming (KM) mice were subjected to 60 min of 70% hepatic ischemia 30 min after the administration of BH4 or saline. After reperfusion, survival was evaluated. The histologic appearance and ALT, BH4, nitrite/nitrate, 8-isoprostane, and eNOS protein expression levels were measured.. The 1-wk survival rate was 66.67% in the BH4 group and 33.33% in the saline group. The serum ALT values in the BH4 group 1, 3, 6, 12, and 24 h after reperfusion were significantly lower than those of the saline group. A histologic examination of the liver revealed only a small necrotic area in the BH4 group as opposed to massive necrosis in the saline group. The percentage values of the hepatic necrotic area 24 h after reperfusion were significantly less for the BH4 group than for the saline group. The nitrite/nitrate levels in the liver tissue were significantly increased by ~2-fold in the BH4 group compared with the saline group. The free radical indicator 8-isoprostane was reduced approximately 50% in the BH4 group compared with the saline group. Western blotting showed that the level of eNOS protein between the groups was not significantly different.. BH4 significantly improved the survival rate by reducing liver failure. This was supported by the histologic findings, and the mechanism was explored. According to the results, we suggest that BH4 prevents liver damage from I/R injury by attenuating reactive oxygen species and increasing NO synthesis, and might provide a novel and promising therapeutic option for preventing I/R injury.

Topics: Alanine Transaminase; Animals; Biopterins; Delayed Graft Function; Dinoprost; Liver; Liver Diseases; Liver Transplantation; Mice; Mice, Inbred Strains; Nitrates; Nitric Oxide Synthase Type III; Reperfusion Injury; Superoxides; Vitamin B 12

Glyceraldehyde-3-phosphate dehydrogenase (GAPDH), a glycolytic enzyme, plays an important role in glycolysis. It was reported that GAPDH undergoes S-nitrosylation, which facilitated its binding to Siah1 and resulted in nuclear translocation and cell apoptosis. The results of this study show that GAPDH S-nitrosylation, Siah1 binding, translocation to nucleus, and concomitant neuron death occur during the early stages of reperfusion in the rat four-vessel occlusion ischemic model. N-Methyl-D-aspartate receptor antagonist MK801, neuronal nitric oxide synthase inhibitor 7-nitroindazole, or monoamine oxidase-B inhibitor (R)-(-)-deprenyl hydrochloride could inhibit GAPDH S-nitrosylation and translocation and exert neuroprotective effects.

Topics: Active Transport, Cell Nucleus; Analysis of Variance; Animals; Apoptosis; Brain Ischemia; CA1 Region, Hippocampal; Cell Nucleus; Dizocilpine Maleate; Enzyme Inhibitors; Glyceraldehyde-3-Phosphate Dehydrogenases; Humans; Indazoles; Male; Monoamine Oxidase; Neuroprotective Agents; Nitric Oxide; Nitric Oxide Synthase Type I; Nitroso Compounds; Nuclear Proteins; Pyramidal Cells; Rats; Rats, Sprague-Dawley; Receptors, N-Methyl-D-Aspartate; Reperfusion Injury; Selegiline; Ubiquitin-Protein Ligases; Vitamin B 12

Superoxide (O(2)(•-)) is implicated in inflammatory states including arteriosclerosis and ischemia-reperfusion injury. Cobalamin (Cbl) supplementation is beneficial for treating many inflammatory diseases and also provides protection in oxidative-stress-associated pathologies. Reduced Cbl reacts with O(2)(•-) at rates approaching that of superoxide dismutase (SOD), suggesting a plausible mechanism for its anti-inflammatory properties. Elevated homocysteine (Hcy) is an independent risk factor for cardiovascular disease and endothelial dysfunction. Hcy increases O(2)(•-) levels in human aortic endothelial cells (HAEC). Here, we explore the protective effects of Cbl in HAEC exposed to various O(2)(•-) sources, including increased Hcy levels. Hcy increased O(2)(•-) levels (1.6-fold) in HAEC, concomitant with a 20% reduction in cell viability and a 1.5-fold increase in apoptotic death. Pretreatment of HAEC with physiologically relevant concentrations of cyanocobalamin (CNCbl) (10-50nM) prevented Hcy-induced increases in O(2)(•-) and cell death. CNCbl inhibited both Hcy and rotenone-induced mitochondrial O(2)(•-) production. Similarly, HAEC challenged with paraquat showed a 1.5-fold increase in O(2)(•-) levels and a 30% decrease in cell viability, both of which were prevented with CNCbl pretreatment. CNCbl also attenuated elevated O(2)(•-) levels after exposure of cells to a Cu/Zn-SOD inhibitor. Our data suggest that Cbl acts as an efficient intracellular O(2)(•-) scavenger.

Topics: Aorta; Apoptosis; Atherosclerosis; Cell Line; Cell Survival; Cytoprotection; Endothelium, Vascular; Free Radical Scavengers; Humans; Mitochondria; Oxidative Stress; Reperfusion Injury; Superoxides; Vitamin B 12; Vitamin B Complex