| Abstract |
Διατμηματικό, συνεργαζόμενα Τμήματα Χημείας και Βιολογίας. Oxidative stress in humans results in the production of reactive oxygen species (ROS), which are implicated in the pathogenesis of chronic diseases, such as cardiovascular diseases and cancer. Various dietary components capable of quenching ROS may contribute to the cell defense system against oxidative damage. The wide presence of polyphenolic compounds in nature has drawn hightened research attention due to their biological properties, among which is their antioxidant activity. Low mortality rates from cardiovascular disease and cancer have been observed in the Mediterranean region, and have purportedly been attributed to the composition of its traditional dietary patterns. The antioxidant properties of herbs, however, used in the traditional Mediterranean diet and medicine have not been widely investigated, even though they may turn to be significant in comprehending their role in disease prevention. In the present work Mediterranean herb and black tea infusions were investigated, in a non-digestion model system, for possible pro/antioxidant activity promoted by prooxidant iron ions. In the presence of different substrates all of the infusions used exhibited antioxidant activity in comparison to the iron control. The variable, yet effective, antioxidant capacity of the investigated infusions indicates that their antioxidant components can quench ROS generating activity brought on different substrates. In addition, the behavior of Mediterranean herb and black tea infusions was investigated in the presence of iron under in vitro digestion conditions. All infusions exhibited variable antioxidant activity in comparison to the controls, in the absence or presence of digestive enzymes and bile salts. The observed antioxidant activity correlated well with polyphenol or protein content, but not with iron in dialysates. The results of the in vitro digestion assay demonstrate that it can offer more details on potential antioxidants than a non-digestion model system. The qualitative and quantitative analysis of the aqueous infusion of sage (Salvia fruticosa L.) by HPLC, demonstrate the presence of the diterpenes carnosic acid, carnosol and rosmanol, and the phenolic acid caffeic acid, known for their antioxidant properties. The seasonal quantitative differences of carnosic acid and rosmanol in samples of sage, indicate a possible role of these diterpenes in counteracting oxidative stress in plants.
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Αντιοξειδωτική δραστικότητα αρωματικών φυτών της Μεσογείου
