Electron Paramagnetic Resonance Spectrometry-based Assessment of Free Radicals Scavenging Potential of N-acetyl Tryptophan Glucoside

Abstract

Gamma radiation generates free radicals in biological system by inducing cellular water radiolysis. If not neutralised, free radicals oxidise vital bio-macromolecules causing structural and functional impairment and contribute to cell death. In present study, free radical scavenging activities of a novel bacterial secondary metabolite, N-acetyl tryptophan glucoside (NATG) was assessed against gamma-radiation induced damage in vitro and in vivo models. Effect of irradiated NATG (UV and gamma radiation 8 Gy and 20 Gy) on its free radical (DPPH radicals) and SOD-like activity was evaluated using EPR spectrometry. To assess the effect of NATG irradiation on its antioxidant potential, EPR based ascorbate, PBN and NO radicals scavenging activities were evaluated in blood and spleen tissue of strain A male mice. Results of the study indicated significant (p < 0.05) increase in DPPH radicals scavenging ability of irradiated NATG as compared to un-irradiated NATG. Similarly, irradiated NATG exhibited significant (p < 0.05) elevation in SOD-like activity as compared to control. Subsequently, NATG treatment displayed enhanced antioxidant activity as evident by significant (p < 0.05) decline in ascorbate, PBN and NO radicals at 1 h and 2h in blood and spleen tissues homogenate of treated mice as compared to control group. In conclusion, NATG possesses significant free radicals scavenging and radio protective capabilities against gamma radiation induced oxidative stress.