Effect of ascorbic acid and hydrogen peroxide on mouse neuroblastoma cells

Abstract

Ascorbic acid is one of the antioxidant compounds widely used against free radical stress. The present study was undertaken to examine whether ascorbic acid and hydrogen peroxide (H2O2), alone or in combination, could influence cell viability. The murine neuroblastoma cell line, N2a, was used to perform a dose response curve for ascorbic acid. It was observed that ascorbic acid alone at physiological concentrations (0.1–0.4 mM) did not cause any cell death. However, at pharmacological concentrations (1–6 mM), ascorbic acid caused dose-dependent cell death. The lethal concentration at which 50% cells were killed (LC50) was determined to be approximately 3.141 mM ascorbic acid at 24 h. H2O2 up to 300 μM alone did not cause significant cell death. In the combined treatment, when the cells were treated with ascorbic acid at physiological concentrations (0.4 mM) and H2O2 at 400 μM, higher rates of cell death were observed compared to the cell death rates caused by either compound alone. Subsequent experiments revealed that cell death was partly mediated through the loss of total glutathione levels in the cells. These data suggest that the combination of ascorbic acid and H2O2 is disadvantageous for cancer cell survival. Further studies are required to ascertain the physiological significance of these observations.

Attenuating effect of N-acetyl-L-cysteine against acute cocaine toxicity in rat C6 astroglial cells

“…2B). Lack of NAC toxicity in astroglial cells corroborated a similar viability result with ascorbic acid as previously reported (20). …”

Intramitochondrial Ascorbic Acid Enhances the Formation of Mitochondrial Superoxide Induced by Peroxynitrite via a Ca2+-Independent Mechanism

“…Sub-optimal levels of peroxynitrite may also promote maximal mitochondrial superoxide formation through either CDM, uniquely dependent on the mitochondrial Ca 2+ accumulation triggered by RyR agonists [ 5 , 6 ], or RDM, taking place under conditions associated with suppression of electron transport, secondary to inhibition of complex III [ 4 , 6 ]. The enhancing effects mediated by AA in cells exposed to peroxynitrite and other oxidants were also described in other laboratories [ 30 , 31 , 32 ]. Although it is difficult to extrapolate the significance of experimental results obtained with cultured cells to draw conclusions relevant to human physio-pathology, reports in the literature describe deleterious effects mediated by acute supplementation of AA to individuals affected by β-thalassaemia major [ 33 ], as well as idiopathic haemochromatosis and dietary iron overload [ 34 , 35 ].…”

“…Intravenous administration of pharmacological concentrations of vitamin C also promotes cancer cell death in experimental animals [ 28 ] and in humans [ 29 ]. In addition, AA can be engaged in specific reactions leading to enhanced responses to specific reactive species [ 11 , 12 , 30 , 31 , 32 ]. As an example, we found that pre-exposure of U937 cells to AA enhances their susceptibility to the deleterious effects mediated by various hydroperoxides, in particular peroxynitrite [ 11 , 12 ].…”

Biochemical changes associated with ascorbic acid–cisplatin combination therapeutic efficacy and protective effect on cisplatin-induced toxicity in tumor-bearing mice

“…3 ) which could be an important contributory factor in resulting better cytotoxic effects during combination treatment against murine ascites Dalton's lymphoma and it is aided by decreased GSH levels in tumor cells as observed in the present study ( Table 2 ). Combination treatment of AA and H 2 O 2 has been reported to cause a significant decrease in GSH levels in the mouse neuroblastoma cells leading to effective death of cancer cells [57] . Increased cisplatin-induced apoptosis has been reported in ascorbate-supplemented cells by upregulation of MLH1 and p73 gene [58] .…”