2. Materials and methods
2.1. Participants
Four male, and twenty-four female healthy elderly volunteers
(mean age 65.05±3.56 years) were recruited to participate in
this study. The Ethical Committee of Faculty of Medicine, Khon
Kaen University, have approved the study, and all subjects gave
written informed consent. Prior to participation, each volunteer
signed an informed consent form and completed a medical
health questionnaire. All subjects were also undergone extensive
medical evaluation in order to ascertain subject suitability
for entering the double-blind phase of trial. Additionally, they
were free of any herbal or prescribed medication that interfered
on the function of nervous system. Habitual smokers consuming
more than 10 cigarettes/day were excluded from this study. All
participants should abstain from caffeine containing products
throughout each study day and alcohol for a minimum of 12 h
prior to the test session. They were divided into four groups:
placebo, CA250, CA500 and CA750 mg/day. Each group contained
1 male and no one dropout from the project. Moreover,
no significant difference about mean age, education