Individuals will arrive at the Risk Factor Modification Centre, St. Michael's Hospital between the hours of 8:00 and 10:00am after a 10 to 12-hour fast on seven separate mornings. They will not have consumed any antihypertensive medications on the study mornings. Each visit will be separated by a minimum of a week. Since the half-life of ginsenosides in humans is less than 24-hours, to allow for a washout of approximately seven half-lives.
In each of the four studies, when individuals arrive at our clinic on a test day they will first have their weight measured and subsequently rest in the seated position. They will then have a catheter inserted into a forearm vein, which will be kept patent by saline. From this device, a registered intravenous nurse will obtain a series of 7ml blood samples. Blood will be taken at 30-min intervals. Subsequently, individuals will fill out forms detailing their pharmacological regimen for the previous 24-hours and their diet (dinner) and activity (sleep, urination, morning routine) regimen for the previous 12-hours. As well, they will detail any adverse events that they experienced since their previous visit. Individuals will then have their office BP measured with a mercury sphygmomanometer until three consecutive measurements of both SBP and DBP \<5 mmHg different are obtained. At this point, BP should be steady and subjects will be fitted with an ABPM. Measurements will be taken every 5-min for 30-min, for a total of seven measurements. After the seventh measurement (time 0-min), measurements will be taken automatically every 10-min for 180-min. At time 0-min, treatment or placebo capsules will be consumed. At time 60-min a 360-calorie Ensure® breakfast will be consumed within 5-min. Blood samples will be drawn at 30-min intervals, starting at time 0-min. For 24-hours after the ingestion of treatment, a record of any side effects will be detailed by the participants and then provided to us.
