The effects of the herbal preparation, STW5-II, on gastrointestinal motility in healthy volunteers

INTERVENTION: This trial will observe the physiological gastrointestinal responses to a single dose (20 drops, 1.1 ml) of STW5‐II to investigate the mechanisms by which this herbal preparation may exert its gastrointestinal symptom relieving effects. Two study visits, separated by at least four days, are required. Participants will receive, in randomised, double‐blind fashion, oral administration of either (i) 20 drops (1.1ml) of STW5‐II or (ii) 20 drops (1.1ml) control solution (i.e. containing no active ingredients). For both study visits, participants will fast for 14 hrs overnight, and abstain from alcohol and vigorous exercise for 24 hrs prior to each visit. On each study day, participants will attend the Clinical Research Facility, Adelaide Medical School, Adelaide Health and Medical Sciences Building at 8:30am. Upon arrival, the participant will be intubated with a custom‐built manometric catheter (outer diameter: 4 mm; Dentsleeve International, Mui Scientific, Mississauga, Ontario, Canada) which will be inserted through an anaesthetised nostril and allowed to pass through the stomach and into the duodenum by peristalsis. The manometric catheter, consisting of 16 side‐holes, spaced at 1.5 cm intervals, will measure antropyloroduodenal (APD) pressures (i.e. pressures in the antrum, pylorus and duodenum). Six side‐holes (channels 1 ‐ 6) will be positioned in the antrum, a 4.5 cm sleeve sensor (channel 7), with 2 channels present on the back of the sleeve (channels 8 and 9), positioned across the pylorus, and 7 channels in the duodenum (channels 10 ‐ 16). The correct positioning of the catheter, so the sleeve sensor straddles the pylorus, will be maintained by continuous measurement of the transmucosal potential difference (TMPD) between the most distal ant CONDITION: Functional Dyspepsia; ; Functional Dyspepsia Oral and Gastrointestinal ‐ Other diseases of the mouth, teeth, oesophagus, digestive system including liver and colon PRIMARY OUTCOME: Motility index of antral pressures.; ; Number and amplitude of antral pressure waves will be measured using a manometric catheter, connected to a computer‐based system running commercially available software (MMS Database software, version 8.17; Solar GI). ; ; The motility index is calculated with the following equation.; MI = In ([number of waves x X amplitude] + 1). [For each study visit, motility index will be calculated per 15 min segment of motility measurement between t = 0 min and t = 180 min.] SECONDARY OUTCOME: Basal pyloric pressure. ; ; Basal pyloric pressure will be measured using a manometric catheter, connected to a computer‐based system running commercially available software (MMS Database software, version 8.17; Solar GI). [For each study visit, basal pyloric pressure will be calculated per 15 min segment of motility measurement between t = 0 min and t = 180 min.] Number and amplitude (mmHg) of antral pressure waves. This is a composite outcome. ; ; Number and amplitude of antral pressure waves will be measured using a manometric catheter, connected to a computer‐based system running commercially available software (MMS Database software, version 8.17; Solar GI). [For each study visit, number and amplitude (mmHg) of antral pressure waves will be measured per 15 min segment of motility measurement between t = 0 min and t = 180 min.] Number and amplitude (mmHg) of duodenal pressure waves. This is a composite outcome. ; ; ; Number and amplitude of duodenal pressure waves will be measured using a manometric catheter, connected to a computer‐based system running commercially available software (MMS Database software, version 8.17; Solar GI). [For each study visit, number and amplitude (mmHg) of duodenal pressure waves will be measured per 15 min segment of motility measurement between t = 0 min and t = 180 min.] Number and amplitude (mmHg) of isolated pyloric pressure waves (IPPWs). This is a composite outcome. ; Number and amplitude of IPPWs will be measured using a manometric catheter, connected to a computer‐based system running commercially available software (MMS Database software, version 8.17; Solar GI). [For each study visit, number and amplitude of IPPWs will be measured per 15 min segment of motility measurement between t = 0 min and t = 180 min.] INCLUSION CRITERIA: Healthy, lean (BMI: 19‐25 kg/m2) male and female volunteers will be included. Participants will be required to be weight‐stable (ie <5% fluctuation) at study entry. Females will be required to be premenopausal and studied during the follicular phase of the menstrual cycle.