Shubhankar Suman1,2, Zubeda Khan2, Mahtab Zarin2, Sudhir Chandna1, Rakesh Kumar Seth2. 1. a Natural Radiation Response Mechanisms Group, Division of Radiation Biosciences, Institute of Nuclear Medicine and Allied Sciences , Delhi , India. 2. b Department of Zoology , University of Delhi , Delhi , India.
Abstract
PURPOSE: To investigate the effect of gamma radiation-induced alterations in antioxidant defence of radioresistant Sf9 insect cells. MATERIALS AND METHODS: Sf9 cells were irradiated at doses ranging from 0.5-200 Gy. Lipid peroxidation and protein carbonylation levels were observed at 4 h post-exposure along with reduced glutathione/oxidized glutathione (GSH/GSSG) profile as well as specific activities of redox active enzymes superoxide dismutase (SOD), catalase, ascorbate peroxidase (APOx), and glutathione reductase (GR). Human brain malignant glioma (BMG-1) cells were used for comparing radiation response of mammalian cells. RESULTS: Sf9 cells displayed significantly less radiation-induced reactive oxygen/nitrogen species (ROS/RNS) generation, protein carbonylation and growth inhibition as compared to mammalian cells. Sf9 cells have higher basal APOx (∼4-fold), catalase (∼1.7-fold), SOD (∼1.3-fold) activity and GSH level (∼2.2-fold) compared to mammalian cells. A radiation dose-dependent increase in SOD, Catalase and APOx activity was found in Sf9 cells at least up to 100 Gy dose, while maximum activity in mammalian cells was achieved by 10 Gy. CONCLUSION: The present study suggests that Lepidopteran insect cells carry a stronger antioxidant system that protects against radiation-induced macromolecular damage, growth inhibition and cell death.
PURPOSE: To investigate the effect of gamma radiation-induced alterations in antioxidant defence of radioresistant Sf9 insect cells. MATERIALS AND METHODS: Sf9 cells were irradiated at doses ranging from 0.5-200 Gy. Lipid peroxidation and protein carbonylation levels were observed at 4 h post-exposure along with reduced glutathione/oxidized glutathione (GSH/GSSG) profile as well as specific activities of redox active enzymes superoxide dismutase (SOD), catalase, ascorbate peroxidase (APOx), and glutathione reductase (GR). Humanbrain malignant glioma (BMG-1) cells were used for comparing radiation response of mammalian cells. RESULTS: Sf9 cells displayed significantly less radiation-induced reactive oxygen/nitrogen species (ROS/RNS) generation, protein carbonylation and growth inhibition as compared to mammalian cells. Sf9 cells have higher basal APOx (∼4-fold), catalase (∼1.7-fold), SOD (∼1.3-fold) activity and GSH level (∼2.2-fold) compared to mammalian cells. A radiation dose-dependent increase in SOD, Catalase and APOx activity was found in Sf9 cells at least up to 100 Gy dose, while maximum activity in mammalian cells was achieved by 10 Gy. CONCLUSION: The present study suggests that Lepidopteran insect cells carry a stronger antioxidant system that protects against radiation-induced macromolecular damage, growth inhibition and cell death.