Inhibition of Biochemical Model Reactions for Inflammatory Processes by Plant Extracts: A Review on Recent Developments

All processes of oxygen activation include very reactive intermediates. Therefore, aerobic cells must cope with- and to some extent also adapt to- oxidative stress provoked for example by infections or intoxications, where these reactive intermediates accumulate. Dependent on the strength of these impact, several symptoms indicate the deviation from normal, steady-state-metabolism. Intrinsic radical scavenging processes or compounds administered with food thus have to warrant metabolic control within certain limits. Antioxidants which in many cases are free radical scavengers or quenchers of activated states comprise a wealth of classes of organic molecules including phenolics, probably as the most prominent ones. In this communication mechanisms of protection from oxidative damage are discussed. Furthermore, examples of antioxidative functions of a few important natural products in certain diseases are reported.