Research justified that natural antioxidants and bioactive agents related to antioxidant effects could act on signal transduction pathways and/or phase II enzyme activities directly and/or indirectly. These molecules can also influence the apoptotic genes. In the case of plant extracts, which contain several active compounds, one might consider it is impossible to discover the single mechanism of action. This problem becomes even more complicated, when we bring the obtained data of in vitro and in vivo experiments into consideration. Therefore the multifactorial actions must be analyzed in long-term in vivo studies on redox homeostasis. The questions are: can the absorbed compounds of natural extracts from the gastrointestinal tract influence the changed cellular redox states and how can these molecules act on the redox homeostasis of blood in IBD patients? Our aim was to present the protective effect of a natural product made from
Raphanus sativus niger
squeezed juice (0.2 g/die Raphacol bile granule) in a twelve-month clinical study in patients suffering from IBD. Raphacol treatment did not influence the activity of IBD. Beside beneficial subjective judgement, bile acid level was elevated continuously and the values of redox parameters were decreased in the plasma during treatment. The granule diminished the erythrocyte chemiluminescence significantly and the HbA
-level moderately until the beginning of the ninth month. After this, the trend has changed until the end. Data showed that antioxidant and isothiocyanate-rich granule could influence the redox homeostasis of IBD patients even at low dose.