title: SOS-red fluorescent protein (RFP) bioassay system for monitoring of antigenotoxic activity in plant extracts.
abstract: An optical antigenotoxicity assay using genetically engineered red fluorescent bacteria is presented. Exposure of Escherichia coli RS4U to genotoxicants [mitomycin C (MMC), nalidixic acid (NA) and hydrogen peroxide (HP)] resulted in phenotypic red fluorescence proportional to the concentration of the inducer. Except for tannic acid (TA), co-treatment of the genotoxicant-activated bacteria with ascorbic acid (AA) and aqueous plant extracts (Mangifera indica, Psidium guajava and Syzygium cumini) afforded protection against all three genotoxicants. TA was effective in suppressing the genotoxic effect of MMC and HP. The antigenotoxic effect is seen as inhibition of the genotoxicant-triggered red fluorescence. The IC50 of the plant extracts and AA varied with the genotoxicant used. Rec assay verified the antigenotoxic activity of the plant extracts. Folin-Ciocalteu test, FeCl3 test and DPPH assay confirmed the presence of polyphenolic compounds and hydrolyzable tannins in the plant extracts and the antioxidant capacity of the plant samples.
authors.affiliation: Graduate School, University of Santo Tomas, Manila, Philippines. millet@umbc.edu
authors.forename: Amelita
authors.initials: A
authors.lastname: Bartolome
authors.forename: Katheryn
authors.initials: K
authors.lastname: Mandap
authors.forename: Kevim Jhean
authors.initials: KJ
authors.lastname: David
authors.forename: Fortunato
authors.initials: F
authors.lastname: Sevilla
authors.forename: James
authors.initials: J
authors.lastname: Villanueva
mesh_terms: D000975:Antioxidants; D015374:Biosensing Techniques; D004249:DNA Damage / Q000187:drug effects* / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics; D005456:Fluorescent Dyes; D008164:Luminescent Proteins / Q000032:analysis / Q000235:genetics*; D009152:Mutagenicity Tests / Q000379:methods; D010936:Plant Extracts / Q000633:toxicity*; D013014:SOS Response, Genetics; D000097573:Red Fluorescent Protein
chemical_list: D000975:Antioxidants; D005456:Fluorescent Dyes; D008164:Luminescent Proteins; D010936:Plant Extracts; D000097573:Red Fluorescent Protein