Antimutagenic and Radical Scavenging Activity of Wheat Bran

This study examined the mutagenic, antimutagenic and antioxidant activities of the DMSO extracts from the wheat bran. Wheat bran extracts showed no genotoxicity toward Salmonella typhimurium TA98, TA100 and TA102 with or without S9 mix (an external metabolic system). In addition, wheat bran extracts expressed a dose-depend inhibitory effect on the mutagenicity of promutagen aflatoxin B1 (AFB1), an indirect mutagen which requires metabolic activation, and 3-(5-nitro-2-furyl)acrylic acid (5-NFAA), 2-nitrofluorene (2NF) and hydrogen peroxide (H 2 O 2), direct mutagens, in Salmonella typhimurium TA98, TA100 and TA102 strains. Significant total antioxidant capacity of wheat bran extract was found by two standard spectroscopic assays based on ABTS and DPPH reagents. A special attention was focused to the reactive radical scavenging capacity of bran extract as one of its antioxitant activities. Wheat bran extract possessed higher ability to scavenge oxygen- and carbon-centered reactive radicals generated by the thermal decomposition of K 2 S 2 O 8 than BHT (70 and 65% scavenged radicals, respectively) during the electron paramagnetic resonance (EPR)/spintrapping test. The total phenolic content of wheat bran samples expressed in gallic acid equivalent was 2.7 mg/g, total flavonoid content expressed in rutin equivalent was 70.8 μg/g and the most abundant phenolic acids established by GC-MS method were isoferulic (3-hydroxy-4-metoxycinnamic) and ferulic (4-hydroxy-3-metoxycinnamic) acid, sinapic, caffeic, p -coumaric and vanillic acids.