A novel method for evaluating free radical scavenging abilities of antioxidants using ultraviolet induction of bacteriophage lambda.
A novel biological method used to evaluate free radical scavenging abilities of antioxidants using ultraviolet (UV) induction of bacteriophage lambda in lysogenic Escherichia coli kappa12 (lambda+) has been developed. This method is based on the induction of bacteriophage lambda from lysogenic cycle to lytic cycle by ultraviolet irradiation, and formation of free radicals during the course of induction. In the experiments, 10(8)cells/ml and 30s (39J/m2) were determined as the cell density of the lysogenic bacterium and UV irradiation time, respectively. The reliability of this method was demonstrated by electron paramagnetic resonance (EPR) spectroscopy and spin trapping with DMPO. This method had good reproducibility with intra-day variations (RSD, %) of less than 4% and inter-day variations (RSD, %) of less than 5%, respectively. By this method, the free radical scavenging abilities (ID50) of well-known antioxidants such as glutathione, superoxide dismutase (SOD), catalase (CAT) and carotenoids were determined quantitatively. The results were consistent with the ones obtained by conventional methods for evaluating free radical scavenging abilities. This developed method is reliable and uses common instruments and inexpensive, stable reagents, thus it could be utilized as a routine laboratory quantitative assay to screen a large number of substances that have potential to scavenge the free radical.
Yang
Qiao
Q
College of Life Sciences, Wuhan University, Wuhan, 430072, PR China.
Zhang
Xiao-Ling
XL
Zhang
Jun-Xiang
JX
Fan
Cheng-Peng
CP
Fang
Cheng-Xiang
CX
D000975:Antioxidants / Q000494:pharmacology*; D010582:Bacteriophage lambda / Q000528:radiation effects*; D001681:Biological Assay / Q000379:methods*; D002470:Cell Survival; D015169:Colony Count, Microbial; D004578:Electron Spin Resonance Spectroscopy / Q000379:methods; D048168:Escherichia coli K12 / Q000528:radiation effects; D016166:Free Radical Scavengers / Q000378:metabolism / Q000494:pharmacology*; D008242:Lysogeny / Q000528:radiation effects; D019097:Spin Trapping / Q000379:methods; D014466:Ultraviolet Rays
D000975:Antioxidants; D016166:Free Radical Scavengers