Abstract 252: Effects of black raspberry extract (BRB) and related compounds on mutagenesis induced by the tobacco carcinogen, dibenzo(a,l)pyrene and its metabolites in cultured rat oral fibroblasts

BRB powder and extracts have been shown to inhibit tumorigenesis in oral and other alimentary-tract sites in animal models; and have promising effects on markers of carcinogenesis in several human trials. The purpose of this study was to compare the inhibitory effects of BRB and two related compounds (protocatechuic acid and kaempferol) on mutagenesis and DNA adduct formation induced by the tobacco carcinogen dibenzo[a,l]pyrene (DBP) and its metabolites, DBP-diol and DBP-diol epoxide (DBPDE), in a rat oral epithelial cell line. Mutagenesis and DNA adduct formation induced by DBP, DBP-diol and DBPDE were monitored in rat oral epithelial and fibroblast cells, containing a lacI mutagenesis reporter gene; and the order of potency in both adduct formation and mutagenesis was DBPDE>>DBP-diol>>DBP in both cell types. In the fibroblasts for mutagenesis, the potencies (in units of mutants/10E5 pfu /uM) were: DBPDE, 16,320; DBP-diol, 25; DBP1.7, (above background); background was 2.9., Similar results were obtained for epithelial cells. Analysis of DNA adducts levels is still in progress and results thus far (in units of cis + trans isomers of anti-DBPDE-dA/10E6 A, are: DBPDE, 2096, DBP-diol ≈1.8, DBP Citation Format: Joseph B. Guttenplan, Wieslawa Kosinska, Tianzhen Han, Kun-Ming Chen, Shangmin Zhang, Krishnegowda Gowdahalli, Amin Shantu, Gary Stoner, Karam El-Bayoumy. Effects of black raspberry extract (BRB) and related compounds on mutagenesis induced by the tobacco carcinogen, dibenzo(a,l)pyrene and its metabolites in cultured rat oral fibroblasts. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 252. doi:10.1158/1538-7445.AM2014-252