Abstract

Stress affects neuroendocrine stress response system, oxidative and nitrosative stress. Some reports claim that antioxidants and antistressors could attenuate these alterations. This study was realized to investigate antistress and antioxidant effects of Hypericum perforatum, Melissa officinalis, Valeriana officinalis and Passiflora incarnata extracts on repeated restraint (RS) in rats. Thirty-six rats were equally divided into six groups: A (control), B (only RS treated), C (H. perforatum + RS treated), D (M. officinalis + RS treated), E (V. officinalis + RS treated), F (P. incarnata + RS treated). Cortisol, lipid peroxidation, protein oxidation and nitric oxide (NO) levels escalated dramatically in group B compared to control, whereas almost all of them diminished remarkably again in groups C, D, E and F. Besides slight alterations of reduced glutathione content and glutathione-s-transferase, catalase activities were recorded between groups. Among vitamins only depletion of vitamin E was significant in Group B comparing to control. Interestingly administration of each plant extract led to increments of vitamins A and E even when compared to control. The results revealed that the aforementioned plant extracts has  remarkable potentials to counteract repeated RS caused alterations of cortisol as well as oxidative and nitrosative stress biomarkers probably through their antistress, antioxidant and free radical defusing effects.

Key words: Some medicinal plants, neuroendocrine stress response system, oxidative stress, nitrosative stress, restraint stress antioxidant.