Influence of rosmarinic acid early intervention on the behavior change and the levels of IL-1β and IL-6 in the hippocampus of PTSD model rats

Abstract

Objective To investigate the effect of rosmarinic acid on the behavioral changes in enhanced single prolonged stress(ESPS) model rats and the levels of interlukin-1β(IL-1β) and interlukin-6(IL-6) in the hippocampus. Methods 48 adult male Sprague Dawley rats were randomly divided into six groups (n=8): Control group, Control+ RA(L) group, Control+ RA(H) group, ESPS group, ESPS+ RA(L)group and ESPS+ RA(H) group.Behavioral changes of these rats were analyzed by open field test and elevated plus-maze.The levels of IL-1β and IL-6 were measured by enzyme linked immunosorbent assay(ELISA). Results (1) Open field test showed that the number of central region entering and the fraction of time exploring in center of ESPS group were significantly reduced than that of Control group((18.13±10.15)times, (26.68±10.06)%) and ESPS+ RA(H) group((16.88±8.81)times, (25.08±8.52)%)(P 0.05). It also showed no significant difference among Control+ RA(L) group, Control+ RA(H) group and Control group.(3) Compared with ESPS group, RA(10mg/kg) reduced the levels of IL-1β and IL-6 in the hippocampus, but RA(5mg/kg) did not have this effect.(4) Correlation analysis results showed the level of IL-1β in the hippocampus was negatively related with the ameliorated PTSD-like behaviors of ESPS exposure rats. Conclusion RA can ameliorate PTSD-like behaviors of ESPS exposure rats, and this effect may be carried out by down-regulating the levels of IL-1β and IL-6 in the hippocampus, especially the IL-1β. Key words: Rosmarinic acid; Posttraumatic stress disorder; Interlukin-1β; Interlukin-6; Rat