Hydrogen Peroxide Induced Oxidative Stress Damage and Antioxidant Enzyme Response in Caco-2 Human Colon Cells

Abstract

Studies were conducted to evaluate the cell damage caused by exposing human colon carcinoma cells, Caco-2, to hydrogen peroxide at concentrations varying from 0 to 250 microM for 30 min. Evaluation of cell viability, as measured by trypan blue dye exclusion test, showed that the loss of viability was < 5% at concentrations up to 250 microM hydrogen peroxide. Cell membrane damage and DNA damage as measured by the leakage of lactate dehydrogenase and the comet assay, respectively, were significantly high at concentrations >100 microM hydrogen peroxide compared to those of the control. Antioxidant mechanisms in Caco-2 cells were evaluated by measuring catalase, superoxide dismutase, and glutathione peroxidase activities. Catalase activities remained constant in cells treated with 50-250 microM hydrogen peroxide. Superoxide dismutase activity decreased, whereas glutathione peroxidase activity increased in cells treated with H(2)O(2) concentrations of >50 microM. This study showed that with increasing hydrogen peroxide concentration, cell membrane leakage and DNA damage increased, whereas the three antioxidant enzymes responded differently, as shown by mathematical models.

Transcriptional and Phospho-Proteomic Screens Reveal Stem Cell Activation of Insulin-Resistance and Transformation Pathways Following a Single Minimally Toxic Episode of Ros

“…ES cells were more resistant to OS-induced high molecular weight DNA fragmentation than differentiated cell types [29,42]. ES cells may have an increased DNA repair capacity or endonuclease-protected higher order chromatin similar to some cancer cell lines [43,44]. Consistent with this, the dose-dependent resistance of ES cells to ROS-mediated cell death was similar to Caco2 colon cancer cells and elevated compared to terminally differentiated primary glial cells [44,45].…”

“…ES cells may have an increased DNA repair capacity or endonuclease-protected higher order chromatin similar to some cancer cell lines [43,44]. Consistent with this, the dose-dependent resistance of ES cells to ROS-mediated cell death was similar to Caco2 colon cancer cells and elevated compared to terminally differentiated primary glial cells [44,45]. Low and high dose ROS-inducing therapies have different cytotoxicities and short-and long-term efficacies [46,47] that are likely defined by the immediate cell-specific response to these treatments, similar to the observations made here.…”

Influence of Viral Vector–Mediated Delivery of Superoxide Dismutase and Catalase to the Hippocampus on Spatial Learning and Memory During Aging

“…2A). In other tissues, H 2 O 2 can provoke an increase in GPx activity (39,42,45). Finally, aged SOD1 + CAT rats did not exhibit cognitive impairments, suggesting improved cognition resulted from better homeostatic regulation of redox signaling due to CAT processing of excess H 2 O 2 .…”

Preventive effect of Nile tilapia hydrolysate against oxidative damage of HepG2 cells and DNA mediated by H2O2 and AAPH

“…It is well known that H 2 O 2 itself is not highly reactive, however it forms a highly reactive hydroxyl radical (OH • ) in the presence of transition metal ions, such as Fe 2+ and Cu + . Wijeratne et al (2005) reported that the loss in viability of Caco2 cells exposed to 10 mM H 2 O 2 was caused by the changes in cell membrane permeability. This could lead to the increased entry of toxins to cells.…”