Oxidative stress in fish cells: in vitro studies

Area of Science:

• Environmental toxicology
• Cellular toxicology
• Biomarker discovery

Background:

• Oxidative stress is a key mechanism in chemical toxicity.
• Understanding fish cell responses to toxicants is crucial for environmental monitoring.
• The neutral red assay is a viable method for assessing cytotoxicity.

Purpose of the Study:

• To evaluate the utility of the bluegill sunfish BF-2 fibroblast cell line in a neutral red cytotoxicity assay for studying oxidative stress.
• To investigate the mechanisms of toxicity for hydrogen peroxide and paraquat in BF-2 cells.
• To compare the responses of BF-2 cells to other cell lines.

Main Methods:

• Utilized the neutral red (NR) cytotoxicity assay with BF-2 fibroblasts.
• Exposed cells to hydrogen peroxide (H2O2) and paraquat under various conditions.
• Investigated the roles of glutathione depletion, superoxide dismutase inhibition, metal ion chelation, and calcium homeostasis disruption.

Main Results:

• H2O2 toxicity was enhanced by glutathione depletion and intracellular calcium perturbation.
• Paraquat toxicity was not enhanced by glutathione depletion but was reduced by Fe2+ chelation.
• 1,10-Phenanthroline (Fe2+ chelator) reduced cytotoxicity of both H2O2 and paraquat.
• Intracellular calcium chelation (Quin 2 AM) reduced H2O2 toxicity but not paraquat toxicity.
• BF-2 cells showed sensitivity to nitrofurantoin after BSO treatment.
• The BF-2 cell/NR assay proved suitable for studying fish oxidative stress.

Conclusions:

• The BF-2 fibroblast/NR cytotoxicity assay is a valuable tool for assessing oxidative stress in fish.
• Intracellular calcium homeostasis plays a role in hydrogen peroxide-induced toxicity.
• Differential responses to toxicants highlight the complexity of oxidative stress mechanisms.