Genistein modifies hamster behavioral and expression of inflammatory factors following sub-chronic unpredictable mild stress

Previous studies have pointed to the protective role of genistein against stress adaptations although neuromolecular mechanisms are not yet fully known. With this work, we evaluated the influence of such a phytoestrogen on hamster behavioral and molecular activities following exposure to subchronic unpredictable mild stress. Methods: The motor behaviors of hamsters (n = 28) were analyzed using elevated plus maze (EPM) test, hole board (HB) test, and forced swim test (FST). In addition, neurodegeneration events were assessed with amino cupric silver stain, while expression variations of tropomyosin receptor kinase B (TrkB), nuclear factor kappa-B1 (NF-κB1), and heat shock protein 70 (Hsp70) mRNAs were highlighted in limbic neuronal fields via in situ hybridization. Results: Genistein accounted for increased motor performances in EPM and HB tests but reduced immobility during FST, which were correlated with diminished argyrophilic signals in some limbic neuronal fields. Contextually, upregulated Hsp70 and TrkB mRNAs occurred in hippocampal (HIP) and hypothalamic neuronal fields. Conversely, diminished NF-κB1 levels were mainly obtained in HIP. Conclusion: Hormonal neuroprotective properties of genistein corroborating anxiolytic and antidepressant role(s) through elevated expression levels of stress proteins and trophic factors may constitute novel therapeutic measures against emotional and stress-related motor performances.