Food ingredient design strategies for chemoprevention of disease using phenolic phytochemicals
Abstract (Summary)The chronic diseases such as diabetes mellitus and cardiovascular disease are among the leading causes of death globally. These are strongly associated with obesity as a result of change in dietary pattern towards high calories and reduced physical activity, which now affects both developing and developed countries. Excessive cellular energy from high calorie foods results in incomplete reduction of oxygen resulting in oxidative stress leading to reactive oxygen species (ROS). The harmful effects of ROS can be balanced by the combination of non-enzymatic antioxidants and antioxidant enzymes. Hence, the maintenance of balance between oxidants and antioxidants through well-designed diet that can modulate cellular protection through critical energy and reductant pathways coupled to antioxidant enzymes is essential. Therefore, the aim of this dissertation was to develop strategies for designing diets enriched in phenolic phytochemicals for chemoprevention of diseases. This was achieved through understanding the critical metabolic pathways contributing to cellular protection against oxidation dysfunction-linked chronic diseases. Based on structure-function rationale, the potential antioxidant, anti-hyperglycemia and anti-hypertension functionality of plant foods such as clonal lines of Lamiaceae family, Rhodiola , wine, tea, vegetables (peppers, eggplant and pumpkin) and grains (corn and legume) were investigated. Results indicated that specific phenolic profiles had high anti-hyperglycemia and anti-hypertension potential which generally corresponded to total phenolic content and free radical scavenging-linked antioxidant activity. Dietary chemoprevention of bacterial pathogens such as Helicobacter pylori and Staphylococcus aureus was investigated through inhibition of critical control points that breakdown cellular energy and antioxidant pathways. Results indicated that lemon balm with the highest gallic acid and caffeic acid contents had potent anti-S. aureus activity. L-Lactic acid, a major food ingredient, had high anti-H. pylori activity through inhibition of proline dehydrogenase and catalase. Overall cellular protection through modulation of energy and reductant stimulating metabolic pathways was investigated in model eukaryotes. Rhodiola crenulata with high anti-hyperglycermia activity, induced apoptosis in V14a breast cancer cell line. Further, phenolic phytochemicals from R. crenulata protected Saccharomyces cerevisiae from UV-induced oxidative stress and delayed death. The cellular protection with phenolic phytochemicals was linked to modulation of proline-linked oxidative phosphorylation coupled to pentose phosphate pathway (PPP).
School Location:USA - Massachusetts
Source Type:Master's Thesis
Date of Publication:01/01/2007