Acute Effects of Mango Leaf Extract (Zynamite®) on Cognitive Function, Mood and Stress

Overview

This study aims to assess the effects of a single dose of Zynamite® on performance across a number of cognitive domains (attention, working memory, episodic memory, executive function), as well as during a period of cognitively demanding task performance, and during laboratory-induced stress. Seventy-two healthy healthy males (50%) and females (50%) aged 18-45 years will be recruited from the general population. Participants will be randomised to receive either Zynamite® or placebo at testing visit 1, then the treatment they have not already received at testing visit 2. A single acute dose will be administered on each of the two testing visits, with at least a seven day washout period in between. The study is quantitative; participants will complete questionnaires assessing mood, cognitive tasks and an Observed Multitasking Stressor (OMS) task (with saliva samples, and blood samples for 50% of the sample). The cognitive/mood assessments will take place at baseline, then at 30, 180 and 300 minutes post-dose. The OMS assessments will take place at baseline then between 90 and 130 minutes post-dose. For participants in the bloods sub-sample, blood samples will be taken at baseline and after the 300 minute post-dose assessment. Both testing visits will be identical apart from the treatment allocated.

The proposed study will assess the effects of a single dose of Zynamite® on performance across a number of cognitive domains (attention, working memory, episodic memory, executive function), as well as during a period of cognitively demanding task performance, and during laboratory-induced stress. Zynamite®'s effects will also be assessed in terms of mood, and its ability to modulate the physiological and psychological response to an acute stressor. The study will follow a randomised, double-blind, placebo-controlled, balanced cross-over design, with treatment (Zynamite®, placebo) as a factor. Seventy-two healthy males (50%) and females (50%) aged 18-45 years will be recruited using opportunity sampling. Participants will be randomised to receive either Zynamite® or placebo at testing visit 1, then the treatment they have not already received at testing visit 2. A single acute dose will be administered on each of the two testing visits, with at least a seven day washout period in between. Testing will take place in a suite of testing facilities at the Brain, Performance and Nutrition Research Centre with participants visually isolated from each other. Participants will attend the laboratory on 3 separate occasions, an introductory visit and two testing days (Day 1 and Day 2). Visit 1 (screening/training) The Introductory visit to the laboratory will comprise: briefing on requirements of the study, obtaining of informed consent, health screening, completion of the Caffeine Consumption Questionnaire (CCQ), training on the cognitive and mood measures and collection of demographic data. Visit 2 Participants will attend the laboratory at a pre-arranged time in the morning having consumed a standardised breakfast of cereal and/ or toast at home no later than an hour before arrival. They must have refrained from alcohol for 24 hours and caffeine overnight. On arrival on each day participants will have a baseline rested measurement taken of their heart rate (HR) and galvanic skin response (GSR) taken, will complete the Profile of Mood States (POMS)(Mood/depression/arousal) followed by a 60 minute computerised cognitive assessment (COMPASS - including the Cognitive Demand Battery). This will be followed by completion of the Observed Multitasking Stressor (OMS) test session. This 5-10 minute OMS takes place under observation (which will include being observed by a panel and video and voice recordings) comprises provision of a saliva sample, completion of the State Trait Anxiety Inventory (STAI)-state, and visual analogue scales (VAS) which are completed before and after the stressor. The stressor comprises the performance of a verbal Serial 7s subtraction task whilst concomitantly performing a computerised tracking task. Finally a further saliva sample is taken. HR and GSR are recorded throughout. After the first cognitive/OMS assessment participants will take their treatment for the day and will undergo cognitive/mood assessments identical to the above at 30 minutes, 180 minutes and 300 minutes post-dose. The post-dose OMS assessment will take place between 90 and 130 minutes post-dose. Blood samples will be taken from 50% of the participants both before the pre-dose, baseline assessment and after the 300 minute post-dose assessment. The two testing days (Day 1/Day2) will be identical, with the exception that participants will take a different treatment on each day. Visit 3 (at least 7 days later) The methodology during this visit will be identical to visit 2, with the exception that participants will consume a different treatment during this visit.