Acrolein contributes strongly to antimicrobial and heterocyclic amine transformation activities of reuterin.

Glycerol/diol dehydratases catalyze the conversion of glycerol to 3-hydroxypropionaldehyde (3-HPA), the basis of a multi-component system called reuterin. Reuterin has antimicrobial properties and undergoes chemical conjugation with dietary heterocyclic amines (HCAs). In aqueous solution reuterin is in dynamic equilibrium with the toxicant acrolein. It was the aim of this study to investigate the extent of acrolein formation at various physiological conditions and to determine its role in biological and chemical activities. The application of a combined novel analytical approach including IC-PAD, LC-MS and NMR together with specific acrolein scavengers suggested for the first time that acrolein, and not 3-HPA, is the active compound responsible for HCA conjugation and antimicrobial activity attributed to reuterin. As formation of the HCA conjugate was observed in vivo, our results imply that acrolein is formed in the human gut with implications on detoxification of HCAs. We propose to re-define the term reuterin to include acrolein.

Tactile and vestibular mechanisms underlying ownership for body parts: a non-visual variant of the rubber hand illusion.

Ownership for body parts depends on multisensory integration of visual, tactile and proprioceptive signals. In a previous study, we demonstrated that vestibular signals also contribute to ownership for body parts, since vestibular stimulation increased illusory ownership for a rubber hand. However, it remained an open question whether the vestibular information acts on the visual or on the tactile input. Here, we used a non-visual variant of the rubber hand illusion, manipulating the synchrony between tactile signals from the participant's left and right hand. The results revealed a strong illusory ownership through self-reports (questionnaires) and proprioceptive drift measures. Interestingly, however, there was no influence of vestibular stimulation on illusory ownership and the proprioceptive drift. The present data suggest that vestibular signals do not interfere with the tactile-proprioceptive mechanisms underlying ownership for body parts when visual feedback from the body surface is absent.