Green Tea Ingestion by Rats Does Not Affect Iron Absorption but Does Alter the Composition of the Saliva Proteome
Article first published online: 12 APR 2012
© 2012 Institute of Food Technologists®
Journal of Food Science
Volume 77, Issue 5, pages H96–H104, May 2012
How to Cite
Beverly, A. B., Zhu, L., Fish, T. L., Thannhauser, T., Rutzke, M. A. and Miller, D. D. (2012), Green Tea Ingestion by Rats Does Not Affect Iron Absorption but Does Alter the Composition of the Saliva Proteome. Journal of Food Science, 77: H96–H104. doi: 10.1111/j.1750-3841.2012.02658.x
- Issue published online: 21 MAY 2012
- Article first published online: 12 APR 2012
- MS 20110136 Submitted 1/30/2011, Accepted 1/24/2012.
- iron absorption;
- proline-rich proteins;
Abstract: We tested the hypothesis that rats adapt to the iron absorption inhibitory effects of tea by modifying the expression of salivary proteins. Thirty-six weanling rats were allocated into 6 groups. Two control groups were fed a semipurified diet containing 20 mg Fe2+/kg diet. Two groups were fed spray dried green tea infusion mixed into the diet (28.6 g tea/kg diet) and 2 groups were fed the control diet with a twice daily gavage of a tea solution (0.25 g tea/mL). Saliva samples were collected in 3 groups (control, gavage, and oral) on day 8 (acute) and in the remaining groups on day 31 (chronic). Iron absorption was assessed using a 58Fe3+ tracer administered on day 1 (acute) and day 24 (chronic). 2D gel electrophoresis and mass spectrometry were used to assess the composition of the saliva proteome. There was no significant difference in iron absorption between the 3 groups on either day 1 or day 24. Salivary proline-rich proteins and submandibular gland secretory protein increased to a greater extent in the oral group than in the gavage group, when compared to control, within the same exposure time period. Amylase, chitinase, deoxyribonuclease, cysteine-rich secretory protein 1, and parotid secretory protein all decreased to a greater extent in the oral tea group, compared to the control, within the same exposure time period. Our results show that green tea did not decrease iron absorption in rats but it did have a marked effect on the saliva proteome when given orally.