Oxidative stress induced by hypertension has been reported to cause alterations in neural cytoarchitecture and cognitive dysfunction. Green tea catechins, especially (−)-epigallocatechin-3-gallate (EGCG), have potent antioxidative properties and protect against various oxidative damages. In this study, we examined the impact of hypertension in rats on locomotor activity, learning, and memory, and EGCG was tested for its potential therapeutic effects in treating hypertension-induced impairment. Blood pressure was measured by the tail-cuff method to confirm high blood pressure in spontaneous hypertension rats (SHRs). Locomotor activity in the open field was increased in SHRs, along with learning and memory impairment in the Morris water maze. Daily EGCG treatment reduced the progressive increase in blood pressure in SHRs, and prevented most of the increased locomotor activity in addition to improving learning and memory. EGCG treatment also decreased the increased level of lipid peroxide production in SHRs and enhanced the antioxidation power in plasma that was observed to be decreased in SHRs. EGCG also decreased the concentration of reactive oxygen species in the hippocampi of SHRs. These indicate a therapeutic effect of EGCG in treating hypertension-induced learning and memory impairment, most probably through its powerful antioxidative properties.
aDepartment of Anesthesia, En-Chu-Kon Hospital
bSchool of Dentistry, College of Oral Medicine, Taipei Medical University
cDepartment of Chemical Engineering and Biotechnology, National Taipei University of Technology, Taipei
dDepartment of Psychiatry, Yuan-Shan br. of Taipei Veteran General Hospital, Yilan, Taiwan, ROC
*Mao-Hsien Wang and Wei-Jen Chang contributed equally to the writing of this article.
Correspondence to Kuo-Chi Chang, PhD, Department of Chemical Engineering and Biotechnology, National Taipei University of Technology, 1, Sec. 3, Chung-Hsiao E. Road, Taipei 106, Taiwan, ROC E-mail: email@example.com
Received October 14, 2011
Accepted August 27, 2012