Abstract LB-246: Dietary strawberry phytochemical metabolism in saliva, urine, and genetic biomarkers in smokers and non-smokers

Abstract

Abstract Background: Epidemiological studies implicate tobacco smoke and alcohol consumption are critical risk factors for oral cancer. Yet diets rich in strawberries have shown in rodent and cell studies to have significant protective effects which lower the risk of oral cancer. A fully-characterized strawberry confection was evaluated for safety and adherence in a 6-week, randomized, placebo-controlled, crossover trial involving smokers (n=12) and non-smokers (n=13). Methods: Using HPLC with tandem mass spectroscopy, strawberry phytochemicals in strawberry powder, confection and saliva collected during a 30 minute timed intervention were fully characterized. Buccal tissue was evaluated using pre-validated TaqMan Gene Expression assays corresponding to known smoke-altered oral transcriptome biomarkers used for RT-qPCR analysis. UPLC with mass spectroscopy quantified ellagic acid metabolites (dimethyl-, isourolithin A, urolithin A, B, and C) in 24hr urine collections. Results: Adherence strawberry confections intervention (equivalent to 2 cups of whole strawberries) in smoker (91%) and nonsmokers (99%) was excellent. Toxicities to strawberry intervention was limited to a grade I toxicity (NIH criteria). Significantly less ellagic acid and ellagitannins were observed in saliva compared to confection (p<0.001). Anthocyanin profiles in saliva of smokers differed significantly than non-smokers. One biomarker, Ankyrin Repeat Domain 37 (ANKRD37), was found to be significantly down-regulated in smokers following strawberry confection intervention (p=0.0484). Significant increase (p<0.001) in urolithin A (4.29 ± 1.16 nmol/24hr) and C (0.13 ± 0.03 nmol/24hr) was observed in all participants after strawberry intervention compared to anthocyanin-free diet or placebo intervention. Isourolithin A and urolithin B was observed in 29% and 24% of participants, respectively. Conclusions: A fully characterized strawberry confection was utilized and significant changes in biomarkers of strawberry exposure from saliva, urine and genomic materials were observed. Both ellagitannin metabolites, urolithin A and C would be reliable biomarkers of strawberry exposure. Moreover, differences in ellagitannin metabolite profiles and in ANKRD37 between smokers and non-smokers warrant further studies. Citation Format: Jennifer H. Ahn-Jarvis, Steven K. Clinton, Kenneth M. Riedl, Marta T. Sears, Thomas J. Knobloch, Steven J. Schwartz, Christopher M. Weghorst, Yael Vodovotz. Dietary strawberry phytochemical metabolism in saliva, urine, and genetic biomarkers in smokers and non-smokers. [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 LB-246. doi:10.1158/1538-7445.AM2014-LB-246