scholarly journals Vitamin C Recycling Regulates Neurite Growth in Neurospheres Differentiated In Vitro

Antioxidants ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 1276
Author(s):  
Francisca Espinoza ◽  
Rocío Magdalena ◽  
Natalia Saldivia ◽  
Nery Jara ◽  
Fernando Martínez ◽  
...  
Keyword(s):  
Vitamin C ◽  
Bystander Effect ◽  
High Capacity ◽  
Dehydroascorbic Acid ◽  
Neurite Growth ◽  
Reduced Form ◽  
Incubation Periods ◽  
Neuritic Growth

The reduced form of vitamin C, ascorbic acid (AA), has been related with gene expression and cell differentiation in the cerebral cortex. In neurons, AA is mainly oxidized to dehydroascorbic acid (DHA); however, DHA cannot accumulate intracellularly because it induces metabolic changes and cell death. In this context, it has been proposed that vitamin C recycling via neuron–astrocyte coupling maintains AA levels and prevents DHA parenchymal accumulation. To date, the role of this mechanism during the outgrowth of neurites is unknown. To stimulate neuronal differentiation, adhered neurospheres treated with AA and retinoic acid (RA) were used. Neuritic growth was analyzed by confocal microscopy, and the effect of vitamin C recycling (bystander effect) in vitro was studied using different cells. AA stimulates neuritic growth more efficiently than RA. However, AA is oxidized to DHA in long incubation periods, generating a loss in the formation of neurites. Surprisingly, neurite growth is maintained over time following co-incubation of neurospheres with cells that efficiently capture DHA. In this sense, astrocytes have high capacity to recycle DHA and stimulate the maintenance of neurites. We demonstrated that vitamin C recycling in vitro regulates the morphology of immature neurons during the differentiation and maturation processes.

Vitamin C Recycling Regulates Neurite Growth in Neurospheres Differentiated in Vitro

2020 ◽  
Author(s):  
Francisca Espinoza ◽  
Rocio Magdalena ◽  
Natalia Saldivia ◽  
Nery Jara ◽  
Fernando Martínez ◽  
...  
Keyword(s):  
Vitamin C ◽  
Bystander Effect ◽  
Dehydroascorbic Acid ◽  
Neurite Growth ◽  
Protein Carbonylation ◽  
Reduced Form ◽  
Ros Generation ◽  
Lysine Production ◽  
Neuritic Growth

Abstract Background: The reduced form of vitamin C, ascorbic acid (AA), has been related to antioxidant defense as well as gene expression and cell differentiation in the cerebral cortex. In neurons, AA is mainly oxidized to dehydroascorbic acid (DHA); however, DHA cannot accumulate intracellularly because it induces metabolic changes and cell death. In this context, it has been proposed that vitamin C recycling via neuron-astrocyte coupling maintains AA levels and prevents DHA parenchymal accumulation. To date, the role of this mechanism during the outgrowth of neurites is unknown.Methods: To stimulate neuronal differentiation, adhered neurospheres treated with AA and retinoic acid (RA) were used. Neuritic growth was analyzed by confocal microscopy, and the effect of vitamin C recycling (bystander effect) in vitro was studied using different cells (astrocytes, HL60 and U87). Reactive oxygen species (ROS) generation was also analyzed by flow cytometry and protein carbonylation / carboximetil-lysine production.Results: AA stimulates neuritic growth more efficiently than RA. However, AA is oxidized to DHA in long incubation periods, generating a loss in the formation of neurites. Surprisingly, neurite growth is maintained over time following co-incubation of neurospheres with cells (HL60, U87, or astrocytes) that efficiently capture DHA (Bystander effect). In this sense, astrocytes have high capacity to recycle DHA and stimulate the maintenance of neurites. Finally, our data indicate that DHA induces ROS generation, a condition that results in protein carbonylation and carboximetil-lysine production. Conclusions: We have demonstrated that vitamin C recycling in vitro regulates the morphology of immature neurons during the differentiation and maturation processes.

Role of vitamin C in gastric cancer

2018 ◽  
Vol 01 (1) ◽  
Author(s):  
Takalkar U Vidyadhar
Keyword(s):  
Gastric Cancer ◽  
Vitamin C ◽  
Gastric Juice ◽  
Oxidative Dna Damage ◽  
Preventive Measure ◽  
Dietary Factors ◽  
Preventive Strategy ◽  
H Pylori

Gastric cancer is a multifactorial disease with complex interplay of environmental and genetic factors. Helicobacter pylori (H. pylori) infestation has been identified as the most important etiological agent in the pathogenesis of gastric cancer. Also, the role of dietary factors that is low consumption of fruits and vegetables have been found to be associated with gastric cancer. Among the dietary factors, antioxidants especially vitamin C has been found to confer the strongest protection against gastric cancer. Its anti-proliferative and pro-apoptotic action has been suggested in vitro. Because of its antioxidant activity, it protects cells against oxidative DNA damage caused by toxic effects of reactive oxygen species. It also inhibits production of carcinogenic N-nitroso compound in the stomach. The person with H. pylori infection has low levels of vitamin C in their gastric juice and levels of vitamin C normalizes on eradication of H. pylori. Vitamin C levels are high in gastric mucosa and gastric juice, sometimes more than that of in plasma. But gastric pathological conditions cause lowered secretion of vitamin C into gastric juice. Effect of H. pylori on vitamin C in gastric juice is reversible and on eradication of H. pylori, it returns to normal level. Hence, eradication of H. pylori and chemoprevention with antioxidant supplementation will be an effective preventive strategy to reduce the incidence of gastric cancer and related mortality. Vitamin C and gastric cancer is an area of potential interest for researchers as a preventive measure. Keywords: Vitamin C, H. pylori, gastric cancer.

scholarly journals The Role of Vitamin C in Cancer Prevention and Therapy: A Literature Review

Antioxidants ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 1894
Author(s):  
Marcelo Villagran ◽  
Jorge Ferreira ◽  
Miquel Martorell ◽  
Lorena Mardones
Keyword(s):  
Clinical Trials ◽  
Vitamin C ◽  
Cancer Prevention ◽  
Randomized Study ◽  
Regulation Of Gene Expression ◽  
Water Soluble ◽  
In Vitro Assays ◽  
High Concentration

Vitamin C is a water-soluble antioxidant associated with the prevention of the common cold and is also a cofactor of hydrolases that participate in the synthesis of collagen and catecholamines, and in the regulation of gene expression. In cancer, vitamin C is associated with prevention, progression, and treatment, due to its general properties or its role as a pro-oxidant at high concentration. This review explores the role of vitamin C in cancer clinical trials and the aspects to consider in future studies, such as plasmatic vitamin C and metabolite excretion recording, and metabolism and transport of vitamin C into cancer cells. The reviewed studies show that vitamin C intake from natural sources can prevent the development of pulmonary and breast cancer, and that vitamin C synergizes with gemcitabine and erlotinib in pancreatic cancer. In vitro assays reveal that vitamin C synergizes with DNA-methyl transferase inhibitors. However, vitamin C was not associated with cancer prevention in a Mendelian randomized study. In conclusion, the role of vitamin C in the prevention and treatment of cancer is still an ongoing area of research. It is necessary that new phase II and III clinical trials be performed to collect stronger evidence of the therapeutic role of vitamin C in cancer.

scholarly journals Vitamin C and the Role of Citrus Juices as Functional Food

2009 ◽  
Vol 4 (5) ◽  
pp. 1934578X0900400 ◽  
Author(s):  
Nuria Martí ◽  
Pedro Mena ◽  
Jose Antonio Cánovas ◽  
Vicente Micol ◽  
Domingo Saura
Keyword(s):  
Ascorbic Acid ◽  
Vitamin C ◽  
Dehydroascorbic Acid ◽  
Antioxidant Response ◽  
Intestinal Wall ◽  
Processing Temperature ◽  
High Concentration ◽  
Citrus Juices ◽  
Citrus Extract

The literature on the content and stability of vitamin C (ascorbic acid, AA) in citrus juices in relation to industrial practices is reviewed. The role of vitamin C from citrus juices in human diet is also reviewed. Citrus fruits and juices are rich in several types of bioactive compounds. Their antioxidant activity and related benefits derive not only from vitamin C but also from other phytochemicals, mainly flavonoids. During juice processing, temperature and oxygen are the main factors responsible for vitamin C losses. Nonthermal processed juices retain higher levels of vitamin C, but economic factors apparently delay the use of such methods in the citrus industry. Regarding packing material, vitamin C in fruit juice is quite stable when stored in metal or glass containers, whereas juice stored in plastic bottles has a much shorter shelf-life. The limiting step for vitamin C absorption in humans is transcellular active transport across the intestinal wall where AA may be oxidized to dehydroascorbic acid (DHAA), which is easily transported across the cell membrane and immediately reduced back to AA by two major pathways. AA bioavailability in the presence of flavonoids has yielded controversial results. Whereas flavonoids seem to inhibit intestinal absorption of AA, some studies have shown that AA in citrus extract was more available than synthetic ascorbic acid alone. DHAA is reported to possess equivalent biological activity to AA, so recent studies often consider the vitamin C activity in the diet as the sum of AA plus DHAA. However, this claimed equivalence should be carefully reexamined. Humans are one of the few species lacking the enzyme (L-gulonolactone oxidase, GLO) to convert glucose to vitamin C. It has been suggested that this is due to a mutation that provided a survival advantage to early primates, since GLO produces toxic H2O2. Furthermore, the high concentration of AA (and DHAA) in neural tissues could have been the key factor that caused primates (vertebrates with relative big brain) to lose the capacity to synthesize vitamin C. Oxidative damage has many pathological implications in human health, and AA may play a central role in maintaining the metabolic antioxidant response. The abundance of citrus juices in the Mediterranean diet may provide the main dietary source for natural vitamin C.

scholarly journals Electron Transfer and Binding of thec-Type Cytochrome TorC to the TrimethylamineN-Oxide Reductase inEscherichia coli

2000 ◽  
Vol 276 (15) ◽  
pp. 11545-11551 ◽  
Author(s):  
Stéphanie Gon ◽  
Marie-Thérèse Giudici-Orticoni ◽  
Vincent Méjean ◽  
Chantal Iobbi-Nivol
Keyword(s):  
Electron Transfer ◽  
Biochemical Characterization ◽  
Reduced Form ◽  
Visible Absorption ◽  
Midpoint Potential ◽  
Redox Potentiometry ◽  
Family Based ◽  
Transfer Chain

Reduction of trimethylamineN-oxide (E′0(TMAO/TMA)= +130 mV) inEscherichia coliis carried out by the Tor system, an electron transfer chain encoded by thetorCADoperon and made up of the periplasmic terminal reductase TorA and the membrane-anchored pentahemicc-type cytochrome TorC. Although the role of TorA in the reduction of trimethylamineN-oxide (TMAO) has been clearly established, no direct evidence for TorC involvement has been presented. TorC belongs to the NirT/NapCc-type cytochrome family based on homologies of its N-terminal tetrahemic domain (TorCN) to the cytochromes of this family, but TorC contains a C-terminal extension (TorCC) with an additional heme-binding site. In this study, we show that both domains are required for the anaerobic bacterial growth with TMAO. The intact TorC protein and its two domains, TorCNand TorCC, were produced independently and purified for a biochemical characterization. The reduced form of TorC exhibited visible absorption maxima at 552, 523, and 417 nm. Mediated redox potentiometry of the heme centers of the purified components identified two negative midpoint potentials (−177 and −98 mV) localized in the tetrahemic TorCNand one positive midpoint potential (+120 mV) in the monohemic TorCC. In agreement with these values, thein vitroreconstitution of electron transfer between TorC, TorCN, or TorCCand TorA showed that only TorC and TorCCwere capable of electron transfer to TorA. Surprisingly, interaction studies revealed that only TorC and TorCNstrongly bind TorA. Therefore, TorCCdirectly transfers electrons to TorA, whereas TorCN, which probably receives electrons from the menaquinone pool, is involved in both the electron transfer to TorCCand the binding to TorA.

scholarly journals Developmental axon regrowth and primary neuron sprouting utilize distinct actin elongation factors

2020 ◽  
Vol 219 (5) ◽  
Author(s):  
Shiri P. Yaniv ◽  
Hagar Meltzer ◽  
Idan Alyagor ◽  
Oren Schuldiner
Keyword(s):  
Neurite Growth ◽  
Growth Potential ◽  
Neuronal Regeneration ◽  
Cell Type ◽  
Elongation Factors ◽  
Dynamic Expression ◽  
Unique System

Intrinsic neurite growth potential is a key determinant of neuronal regeneration efficiency following injury. The stereotypical remodeling of Drosophila γ-neurons includes developmental regrowth of pruned axons to form adult specific connections, thereby offering a unique system to uncover growth potential regulators. Motivated by the dynamic expression in remodeling γ-neurons, we focus here on the role of actin elongation factors as potential regulators of developmental axon regrowth. We found that regrowth in vivo requires the actin elongation factors Ena and profilin, but not the formins that are expressed in γ-neurons. In contrast, primary γ-neuron sprouting in vitro requires profilin and the formin DAAM, but not Ena. Furthermore, we demonstrate that DAAM can compensate for the loss of Ena in vivo. Similarly, DAAM mutants express invariably high levels of Ena in vitro. Thus, we show that different linear actin elongation factors function in distinct contexts even within the same cell type and that they can partially compensate for each other.

scholarly journals The Role of Physiological Vitamin C Concentrations on Key Functions of Neutrophils Isolated from Healthy Individuals

Nutrients ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 1363 ◽  
Author(s):  
Stephanie M. Bozonet ◽  
Anitra C. Carr
Keyword(s):  
Vitamin C ◽  
Immune Cell ◽  
Dehydroascorbic Acid ◽  
Optimal Level ◽  
Neutrophil Function ◽  
Neutrophil Extracellular Trap ◽  
Healthy Individuals ◽  
Healthy Humans ◽  
Ascorbate Uptake

Vitamin C (ascorbate) is important for neutrophil function and immune health. Studies showing improved immune function have primarily used cells from scorbutic animals or from individuals with infectious conditions or immune cell disorders. Few studies have focused on the requirements of neutrophils from healthy adults. Therefore, we have investigated the role of vitamin C, at concentrations equivalent to those obtained in plasma from oral intakes (i.e., 50–200 µmol/L), on key functions of neutrophils isolated from healthy individuals. Cells were either pre-loaded with dehydroascorbic acid, which is rapidly reduced intracellularly to ascorbate, or the cells were activated in the presence of extracellular ascorbate. We measured the effects of enhanced ascorbate uptake on the essential functions of chemotaxis, oxidant production, programmed cell death and neutrophil extracellular trap (NET) formation. We found that neutrophils isolated from healthy individuals already had replete ascorbate status (0.35 nmol/106 cells), therefore they did not uptake additional ascorbate. However, they readily took up dehydroascorbic acid, thus significantly increasing their intracellular ascorbate concentrations, although this was found to have no additional effect on superoxide production or chemotaxis. Interestingly, extracellular ascorbate appeared to enhance directional mobilityin the presence of the chemoattractant formyl-methionyl-leucyl-phenylalanine (fMLP). Stimulation of the cells in the presence of ascorbate significantly increased intracellular ascorbate concentrations and, although this exhibited a non-significant increase in phosphatidylserine exposure, NET formation was significantly attenuated. Our findings demonstrate the ability of neutrophils to regulate their uptake of ascorbate from the plasma of healthy humans to maintain an optimal level within the cell for proper functioning. Higher oral intakes, however, may help reduce tissue damage and inflammatory pathologies associated with NET formation.

scholarly journals Bioaccessibility of Antioxidants in Blackcurrant Juice After Treatment Using Supercritical Carbon Dioxide

2021 ◽  
Author(s):  
Urszula Trych ◽  
Magdalena Buniowska ◽  
Sylwia Skąpska ◽  
Ireneusz Kapusta ◽  
Krystian Marszałek
Keyword(s):  
Carbon Dioxide ◽  
Supercritical Carbon Dioxide ◽  
Vitamin C ◽  
Model Experiment ◽  
Dehydroascorbic Acid ◽  
Total Anthocyanins ◽  
The Stability ◽  
Supercritical Carbon ◽  
Thermally Treated

Blackcurrant juice (Ribes nigrum L.) was subjected to supercritical carbon dioxide (SCCD) at 10, 30 and 60 MPa for 10 min at 45°C as well as thermally treated at 45°C and 85°C for 10 min to determine the stability, antioxidant capacity (AC) and bioaccessibility (BAc) of vitamin C, total anthocyanins and their individual monomers. An in vitro gastrointestinal digestion model completed with dialysis was used to assess BAc. The use of SCCD at each of the pressures applied improved the stability of vitamin C, total anthocyanins, and AC before in vitro digestion. As a result of digestion, L-ascorbic acid was oxidized to L-dehydroascorbic acid, and finally, the total content of vitamin C, anthocyanins, and AC decreased. SCCD did not significantly improve the BAc of vitamin C and total anthocyanins. The highest BAc of vitamin C was noted in fresh juice (FJ) (40%) and after mild heat treatment at 45°C (T45) (46%). The highest BAc of total anthocyanins was also noted in the FJ (4.4%). The positive effect of the application of SCCD on the BAc of the delphinidin-3-O-glycosides was observed compared to T45 and thermal pasteurization at 85°C (T85). Moreover, cyanidins were generally more bioaccessible than delphinidins in all samples. AC after digestion was higher in SCCD samples compared to thermally treated measured using ABTS+• and DPPH• assays, whereas in dialysate similar trends were observed only for AC measured using the ABTS+• assay. This phenomenon was justified by the formation of individual metabolites detected by UPLC-PDA-MS / MS in the model experiment with delphinidin-3-O-rutinoside. The protocatechuic acid which is well known as a strong antioxidant was detected in the model experiment after digestion. Further research is needed to better understand the metabolic pathway of anthocyanins and the possible uses of SCCD to improve the health properties of fruit products.

scholarly journals Role of vitamin C in gastric cancer

2018 ◽  
Author(s):  
Takalkar U Vidyadhar
Keyword(s):  
Gastric Cancer ◽  
Vitamin C ◽  
Gastric Juice ◽  
Oxidative Dna Damage ◽  
Preventive Measure ◽  
Dietary Factors ◽  
Preventive Strategy ◽  
H Pylori

Gastric cancer is a multifactorial disease with complex interplay of environmental and genetic factors. Helicobacter pylori (H. pylori) infestation has been identified as the most important etiological agent in the pathogenesis of gastric cancer. Also, the role of dietary factors that is low consumption of fruits and vegetables have been found to be associated with gastric cancer. Among the dietary factors, antioxidants especially vitamin C has been found to confer the strongest protection against gastric cancer. Its anti-proliferative and pro-apoptotic action has been suggested in vitro. Because of its antioxidant activity, it protects cells against oxidative DNA damage caused by toxic effects of reactive oxygen species. It also inhibits production of carcinogenic N-nitroso compound in the stomach. The person with H. pylori infection has low levels of vitamin C in their gastric juice and levels of vitamin C normalizes on eradication of H. pylori. Vitamin C levels are high in gastric mucosa and gastric juice, sometimes more than that of in plasma. But gastric pathological conditions cause lowered secretion of vitamin C into gastric juice. Effect of H. pylori on vitamin C in gastric juice is reversible and on eradication of H. pylori, it returns to normal level. Hence, eradication of H. pylori and chemoprevention with antioxidant supplementation will be an effective preventive strategy to reduce the incidence of gastric cancer and related mortality. Vitamin C and gastric cancer is an area of potential interest for researchers as a preventive measure. Keywords: Vitamin C, H. pylori, gastric cancer.

scholarly journals Role of Vitamin C in Osteoporosis Development and Treatment—A Literature Review

Nutrients ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 2394
Author(s):  
Olga Brzezińska ◽  
Zuzanna Łukasik ◽  
Joanna Makowska ◽  
Konrad Walczak
Keyword(s):  
Vitamin C ◽  
Current Knowledge ◽  
Daily Intake ◽  
Dietary Calcium Intake ◽  
Osteoporosis Prevention ◽  
Mineral Density ◽  
Effective Prevention ◽  
Medline Search

Osteoporosis and associated low energy fractures are a significant clinical problem, especially in the elderly population. The occurrence of a hip fracture is associated with significant mortality and a high risk of disability. For this, apart from the treatment of osteoporosis, effective prevention of both the development of the disease and related fractures is extremely important. One aspect of osteoporosis prevention is proper dietary calcium intake and normal vitamin D3 levels. However, there is some evidence for a potential role of vitamin C in osteoporosis and fracture prevention, too. This review aims to summarize the current knowledge about the role of vitamin C in osteoporosis development, prevention and treatment. The PubMed/Medline search on the role of vitamin C in bone metabolism database was performed for articles between 2000 and May 2020. Reports from in vitro and animal studies seem promising. Epidemiological studies also indicate the positive effect of high vitamin C content in the daily diet on bone mineral density. Despite promising observations, there are still few observational and intervention studies and their results do not allow for unequivocal determination of the benefits of high daily intake of vitamin C or its long-term supplementation.

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