METABOLISM AND ANALYSIS OF CEREAL PHYTOCHEMICALS
Location: Cereal Crops Research
Title: Avenanthramides are bioavailable and accumulate in hepatic, cardiac, and skeletal muscle tissue following oral gavage in rats
Submitted to: Journal of Agricultural and Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: February 16, 2011
Publication Date: March 18, 2011
Citation: Koenig, R.T., Dickman, J.R., Wise, M.L., Ji, L. 2011. Avenanthramides are bioavailable and accumulate in hepatic, cardiac, and skeletal muscle tissue following oral gavage in rats. Journal of Agricultural and Food Chemistry. 59(12):6438-6443.
Interpretive Summary: Avenanthramides are a group of anti-oxidants found, among food crops, exclusively in oat. These metabolites show certain desirable nutritional characteristics, such as inhibition of particular biomarkers for atherosclerosis and reducing inflammation, in laboratory in-vitro model systems. The experiments documented here demonstrate the ability of experimental animals (rats) to adsorb avenanthramides through the digestive track. They also quantify the deposition of these compounds in the plasma and various tissues (heart, muscle, and liver). In addition, the distribution of the avenanthramides in either their free form or as metabolically modified conjugates (glucuronates or sulfonates) was analyzed. A very high percentage of the tissue or plasma localized avenanthramides were found in a conjugated form.
Avenanthramides (AVA), polyphenols found exclusively in oats (Avena sativa L.), may play a role in the anti-inflammatory and anti-atherogenic activity of oats. The bioavailability of AVA has been demonstrated previously, but its distribution at the organ and tissue level and the extent of conjugation following ingestion have been unexplored. Synthetic AVA was administered to 24 rats by oral gavage, whereas 6 control rats received saline. AVA concentrations were measured via HPLC in plasma, liver, heart, and gastrocnemius (GAS) obtained over a 12 h period (0, 2, 4, 12 h; n = 6 at each time point). Samples were extracted with and without glucuronidase-sulfatase to assess the level of conjugation. We conclude that AVA are bioavailable to the blood circulation following oral ingestion in the rat and reach peripheral tissues where they can be taken up by various tissues.