The protective effect of Thai Herbal Sahatsatara formula against white matter injury after chronic cerebral hypoperfusion in middle-aged rats

Abstract

Permanent bilateral common carotid artery occlusion (2VO) in rodents induces chronic cerebral hypoperfusion, mimicking vascular dementia in elderly people. It causes inflammation and oxidative stress, leading to neuronal loss in the hippocampus, white matter injuries and impairments of spatial learning and memory. Thai Herbal Sahatsatara formula (STF) has anti-inflammatory and antioxidant actions which might protect neurons and white matter. This experiment was to investigate the possible protective effects of STF. Twenty-eight middle-aged male Wistar rats (12 months old) were divided into 4 groups: Sham+sterile water (SW), 2VO+SW, 2VO+STF300 and 2VO+STF1000. All animals daily received either SW, STF 300 mg/kg or STF 1000 mg/kg orally after 2VO induction until the end of the experiment. Spatial learning and memory test were examined after 2VO induction for 60 days whereas the numbers of hippocampal neurons and white matter changes in the corpus callosum were investigated after the end of the behavioral test. Chronic cerebral hypoperfusion significantly caused spatial learning and memory deficits and white matter injuries in the corpus callosum while the numbers of hippocampal neurons were not significantly affected. STF (1000 mg/kg) attenuated the impairments of spatial learning and learning flexibility and white matter injuries. This is the first study to demonstrate the ability of Sahatsatara formula to attenuate spatial learning and learning flexibility impairments after chronic cerebral hypoperfusion by protecting the white matter in the corpus callosum. The results support the potential application of Sahatsatara formula against chronic cerebral hypoperfusion.