Bioavailability and Biological Efficacy of Phenolic Compounds in Oat and Extra Virgin Olive Oil: Implication of Exercise

Abstract

Eccentric exercise and atherosclerosis are known to generate reactive oxygen and nitrogen species (RONS) and inflict inflammatory responses, leading to muscle inflammation and coronary artery disease respectively. Selective phenolic compounds from oats (Avenanthramides, AVA) and olive oil (Oleocanthal/Oleacein, Oleo/Olea) have been shown to remove these chemicals and inhibit the progress of inflammation. This dissertation proposed three studies to investigate: (1) The metabolic fate of AVA by measuring plasma concentrations and pharmacokinetic properties of AVA in human after an acute oral ingestion of oat cookies. (2) Whether 8 weeks of dietary supplementation of AVA can affect circulatory immune cells and reduce blood inflammatory markers in response to downhill running (DR) induced muscle inflammation in both male and female subjects. (3) Whether 12 weeks of Oleo/Olea supplementation can inhibit inflammation and endothelial dysfunction in atherosclerotic rats, and combined exercise training would further reduce inflammation and improve immune functions. The findings and conclusions are: (1) AVA found naturally in oats are absorbed in the plasma after oral administration in humans. AVA reach peak plasma concertation 2-3 hours after oral ingestion in human. AVA-B has the slowest elimination rate (Kel) and longest half-life (T1/2) compared to AVA-A and AVA-C, while AVA-C demonstrated the lowest plasma concentrations (Cmax). (2) Oat AVA supplementation reduced circulatory inflammatory cytokine (IL-6) expression and ROS generation (NRB) after DR. AVA in oats also inhibited expression of chemokines (MIP-1β, MCP-1), cell adhesion molecule (VCAM-1) and colony stimulating factors (GM-CSF, G-CSF) induced by DR. Although circulatory immune cells were not affected by oat AVA supplementation, oat supplementation decreased circulatory monocytes activation (CD14+) while oat AVA inhibited neutrophils (CD11b+) and increased NK cells (CD56+) activation after DR. (3) High Oleo/Olea diet tends to increase circulatory leukocytes, granulocytes, neutrophils percentage and inflammatory cytokines (MCP-1, RANTES, NAP-3, M-CSF, GM-CSF) but decrease lymphocytes percentage and anti-inflammatory cytokines (IL-10) in sedentary rats, whereas exercise training significantly reversed these trends of immune markers induced by EVOO supplementation.