Synergy research: Vitamins and secondary plant components in the maintenance of the redox-homeostasis and in cell signaling

Abstract

The maintenance of the redox-homeostasis is an essential task of antioxidants. Reactive oxygen species (ROS) formed during oxidative stress can potentially damage the normal cellular functions and support pathological processes like atherosclerosis in vessels or malignant growth in other tissues, but also the aging process. However, recent findings link ROS also to cell survival and/or proliferation, which revolutionises the age-old dogmatic view of ROS being exclusively involved in cell damage and death. Low concentrations of hydrogenperoxide e.g. are involved in cell signaling and can activate mitogen-activated kinases (MAPK) to initiate cell growth. Nutritional antioxidants like vitamin C or E can promote endothelial cell growth, but can also inhibit growth of muscle cells, and influence MAPK. Thus, keeping the redox-homeostasis in a steady state especially in the context of tissue regeneration appears to be more important than previously known and seems to be a controlled synergistic action of antioxidants and ROS. The present review summarizes the properties and functions of ROS and nutritional antioxidants like the vitamins C and E, and polyphenols in redox-homeostasis. Their relevance in the treatment of various diseases is discussed in the context of a multitarget therapy with nutraceuticals and phytotherapeutic drugs.