The Effects of Soy Extract on Spatial Learning and Memory Damage Induced by Global Ischemia in Ovariectomised Rats

ABSTRACT

Background: The effects of soy extract on memory as well as the oxidative damage to brain tissue induced by ischemia was investigated in ovariectomised (OVX) rats. Methods: The rats were divided into: 1) Sham; 2) OVX; 3) Sham‑Ischemia; 4) OVX‑Ischemia; 5) OVX-‑Ischemia-‑S 20; and 6) OVX-‑Ischemia-‑S 60. The common carotid artery was occluded (30 minutes), and it was then re-‑perfused. The OVX-‑Ischemia-‑S 20 and OVX-‑Ischemia-‑S 60 groups received 20 or 60 mg/kg of soy extract for eight weeks before the ischemia. Results: The Sham-‑Ischemia and OVX-‑Ischemia groups took a longer time to reach the platform while, spent a shorter time in the target quadrant (Q1) than the Sham and OVX. The escape latencies in the OVX-‑Ischemia-‑S 20 and OVX-‑Ischemia-‑S 60 groups were lower while, time spent in the Q1 was higher than that of the OVX-‑Ischemia. In the rotarod test, there were no significant differences between the groups. The hippocampal concentrations of malondialdehyde (MDA) in the Sham-‑Ischemia and OVX-‑Ischemia groups were higher than the Sham and OVX. Pre-‑treatment by 20 and 60 mg/kg of the extract reduced the MDA. Conclusion: It is suggested that soy prevents memory impairment and brain tissue oxidative damage due to ischemia in OVX rats.