News & Events

When

Date - April 9, 2015
1:00 pm - 2:00 pm

What

Ph.D. Thesis Defense
Title: Effects of açaí berry (Euterpe oleracea) extracts on human antioxidant systems and drug metabolism”
Advisor Dr. Raner

Abstract:

This research project focused on the broad objective of studying how natural products can effect oxidative stress in living organisms via positive or negative interactions with specific enzymes and/or transcriptional processes. The current study investigated the potential health benefits of açaí (Euterpe olereacea) in order to deliver effective strategies to treat or mitigate a variety of human ailments. It required isolation of bioactive chemical constituents and identification of biological targets and/or associated molecular mechanisms. Amelioration of oxidative stress resulting from increased production of reactive oxygen species by two discrete mechanisms was studied. One mechanism that is critical to maintaining cellular homeostasis is the induction of cytoprotective antioxidant enzymes such as heme oxygenase-01 and NADPH quinone oxidoreductase to eliminate ROS. Induction of such enzymes involves the Nrf2/ARE signaling pathway. Alternatively, inhibition of toxicologically important cytochrome P450 enzymes such as CYP2A6 and CYP2E1 involved in ROS generation presents yet another potential strategy to reduce oxidative stress. The current study employed bioassay-guided fractionation on açaí berry in collaboration with the Oberlies Research group to study (a) induction of antioxidant enzymes in cultured HepG2 cells and (b) inhibition of CYP2A6 and CYP2E1 using human liver microsomes in vitro. Our results indicated the presence of bioactive constituents in açaí with a potential to modulate Nrf2/ARE pathway and potential induction of cytoprotective enzymes. Crude Açaí fractions showed significant inhibitory activity towards CYP2A6 and CYP2E1, however activity appeared to be lost as the material was separated into individual constituents.