Acute Dose-ranging Effects of Mango Leaf Extract (Zynamite® 15%) on Cognitive Function and Cerebral Blood Flow

Study Overview
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Brief Summary
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Zynamite® is a novel mango (Mangifera indica) leaf extract standardized to contain polyphenol mangiferin.It has previously been shown to enhance brain oxygenation, physical performance and ergogenic parameters following ischemia-reperfusion in healthy humans when consumed alongside other polyphenols. Preliminary data has also indicated that a single 300mg dose of Zynamite® (60%) can improve performance across a range of cognitive tasks.This study aims to evaluate the effects, in healthy adults, of 3 doses of Zynamite® 15% on performance across a number of cognitive domains, as well as during a period of cognitively demanding task performance. A second sub-study will assess cerebral blood flow during cognitively demanding task performance.

Detailed Description
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Extracts made from the leaves of the mango food plant (Mangifera indica L., Anacardiaceae) have a long history of medicinal usage, most likely due to particularly high levels of the polyphenol mangiferin. Zynamite®, is a novel mango (Mangifera indica) leaf extract standardized to contain polyphenol mangiferin which has previously been shown to enhance brain oxygenation and physical performance and ergogenic parameters following ischemia-reperfusion in healthy humans when consumed alongside other polyphenols.A recent study in rats demonstrated a similar effect of Zynamite® on electrophysiological (EEG) spectral power as that seen following caffeine, with a synergistic effect of co-consumption of Zynamite® and caffeine. A concomitant ex vivo study demonstrated increased long-term potentiation (LTP) in rat hippocampal slices, suggesting the potential for Zynamite® to enhance memory. Previous research has also demonstrated that both single doses and chronic administration of polyphenols can beneficially modulate cognitive function, including during cognitively demanding task performance. Previous research has also shown that polyphenols and polyphenol rich treatments can modulate cerebral blood-flow. These findings raise the possibility that Zynamite® may have beneficial effects on psychological and hemodynamic parameters, potentially with some similarities to the effects exerted by caffeine. A recent study expanded on the above assessing the effects of a single dose of Zynamite® (60% of polyphenol mangiferin) 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. The results showed that a single dose of 300 mg Zynamite® significantly improved performance accuracy across the tasks in the battery, with domain-specific effects seen in terms of enhanced performance on an 'Accuracy of Attention' factor and an 'Episodic Memory' factor as well as improved performance across all three tasks (Rapid Visual Information Processing, Serial 3s and Serial 7s subtraction tasks) of the Cognitive Demand Battery sub-section of the assessment, which assesses cognitive function and subjective mental fatigue during sustained performance of mentally demanding tasks. All of these cognitive benefits were seen across the post-dose assessments (30 min, 3 h, 5 h). These results provide the first demonstration of cognition enhancement following consumption of mango leaf extract adding to previous research showing that polyphenols and polyphenol rich extracts can improve brain function. The proposed studies will expand on the existing body of research by assessing the effects of three doses of Zynamite® (this time a lower concentration version containing 15% polyphenol mangiferin) on cognitive performance and cerebral blood flow.

Official Title
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Acute Dose-ranging Effects of Mango Leaf Extract (Zynamite® 15%) on Cognitive Function and Cerebral Blood Flow in Healthy Young Adults

Conditions
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Cognitive Change

Intervention / Treatment
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* Dietary Supplement: Zynamite® 15% 150mg
* Dietary Supplement: Zynamite® 15% 300mg
* Dietary Supplement: Zynamite® 15% 600mg
* Dietary Supplement: Placebo


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Participants must self-assess themselves as being in good health Participants must be aged 18 to 30 years at the time of giving consent Participants must self-report playing video-games (arcade, console, computer, smartphone) for not less than 5 hours a week on average, over the previous 6 months . Exclusion Criteria: Have symptoms of Covid-19 or fall into the 'high' or 'moderate' risk categories from coronavirus as defined by NHS UK. Have any pre-existing diagnosed medical condition/illness which will impact taking part in the study NOTE: the explicit exception to this is controlled hay fever. There may be other, unforeseen, exceptions and these will be considered on a case-by-case basis; i.e. participants may be allowed to progress to screening if they have a condition/illness which would not interact with the active treatments or impede performance. Note asthma is not permitted in this study. Are currently taking prescription medications including habitual use of non-steroidal anti-inflammatory drugs (NSAIDs) (e.g. ibuprofen, aspirin) NOTE: the explicit exceptions to this are contraceptive treatments for female participants, thyroid medication, topical creams and those taken 'as needed' in the treatment of hay fever. As above, there may be other instances of medication use which, where no interaction with the active treatments is likely, and which would not be expected to have any impact on brain function, participants may be able to progress to screening. Have high blood pressure (systolic over 139 mm Hg or diastolic over 89 mm Hg) Have a Body Mass Index (BMI) outside of the range 18.5-29.9 kg/m2 Are pregnant, seeking to become pregnant or lactating. Have learning and/or behavioural difficulties such as dyslexia or ADHD Have a visual impairment that cannot be corrected with glasses or contact lenses (including colour-blindness) Smoke tobacco or vape nicotine or use nicotine replacement products Excessive caffeine intake (>500 mg per day) Have relevant food intolerances/ sensitivities/ allergies Have taken antibiotics within the past 4 weeks Have taken dietary supplements e.g. vitamins, omega 3 fish oils etc. in the last 4 weeks (Note: participation is possible following a 4 week supplement washout prior to participating and for the duration of the study on the proviso that the supplements they are taking are out of choice and not medically prescribed or advised). NOTE: Existing vitamin D use is permitted Have any health condition that would prevent fulfilment of the study requirements (this includes non-diagnosed conditions for which no medication may be taken) Are unable to complete all of the study assessments Are currently participating in other clinical or nutrition intervention studies, or have in the past 4 weeks Has been diagnosed with/ undergoing treatment for alcohol or drug abuse in the last 12 months Have been diagnosed with/ undergoing treatment for a psychiatric disorder in the last 12 months Suffers from frequent migraines that require medication (more than or equal to 1 per month) Sleep disorders or are taking sleep aid medication Any known active infections Does not have a bank account (required for payment)

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 30 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Other
Allocation: Randomized
Intervention Model: Crossover Assignment
Interventional Model Description: Balanced crossover
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Zynamite® 15% 150mg<br>Mango leaf extract (Mangifera indica) | Dietary Supplement: Zynamite® 15% 150mg<br>* leaves of the mango food plant<br>* Other names: Mangifera indica;|
| Active Comparator: Zynamite® 15% 300mg<br>Mango leaf extract (Mangifera indica) | Dietary Supplement: Zynamite® 15% 300mg<br>* leaves of the mango food plant<br>* Other names: Mangifera indica;|
| Active Comparator: Zynamite® 15% 600mg<br>Mango leaf extract (Mangifera indica) | Dietary Supplement: Zynamite® 15% 600mg<br>* leaves of the mango food plant<br>* Other names: Mangifera indica;|
| Placebo Comparator: Placebo<br>Placebo matched for appearance | Dietary Supplement: Placebo<br>* Sunflower oil matched for appearance<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Cerebral blood flow during performance of cognitive tasks | Measured (in umol) using quantitative near infrared spectroscopy (higher indicates increased blood volume) | 60 minutes post-dose | 
| Cerebral blood flow at rest | Measured (in umol) using quantitative near infrared spectroscopy (higher indicates increased blood volume) | 10 minutes | 
| Change in speed of performance from baseline to 300 minutes post dose | This is a composite measure derived from summing the z score reaction time (RT) performance on seven tasks and finding the average: Speed of performance = (Zsimple RT + Zchoice RT + Zdigit vigilance RT + ZRVIP RT + ZNumeric working memory RT + ZPicture recognition RT + ZWord recognition RT) ÷ 7 | 0, 300 minutes post dose | 
| Change in accuracy of cognitive task performance from baseline to 300 minutes post dose | This is a composite measure derived from summing the z score accuracy performance scores on nine tasks and finding the average: Accuracy of performance = (Zaccuracy choice RT + Zdigit vigilance accuracy + ZRVIP accuracy + ZNumeric working memory accuracy + ZCorsi span score + Zimmediate word recall accuracy + Zdelayed word recall accuracy + Zword recognition accuracy + Zpicture recognition accuracy) ÷ 9 | 0, 300 minutes post dose | 
| Change in accuracy of attention from baseline to 300 minutes post dose | This is a composite measure derived from averaging the sum of the the z score accuracy performance scores from the choice reaction time, digit vigilance and Rapid visual information processing tasks | 0, 300 minutes post dose | 
| Change in speed of attention from baseline to 300 minutes post dose | This is a composite measure derived from averaging the sum of the the z score reaction times from the choice reaction time, digit vigilance and Rapid visual information processing tasks | 0, 300 minutes post dose | 
| Change in working memory from baseline to 300 minutes post dose | This is a composite measure derived from averaging the sum of the z score accuracy performance on the numeric working memory task and Corsi block-tapping task | 0, 300 minutes post dose | 
| Change in speed of memory from baseline to 300 minutes post dose | This is a composite measure derived from averaging the sum of the z score reaction times on the numeric working memory task, the delayed picture recognition task and the delayed word recognition task | 0, 300 minutes post dose | 
| Change in episodic memory from baseline to 300 minutes post dose | This is a composite measure derived from averaging the sum of the z score performance on the following cognitive tasks: immediate word recall, delayed word recall, delayed picture recognition, delayed word recognition | 0, 300 minutes post dose | 
| Cognitive function- change in individual task Accuracy for word recall from baseline to 300 minutes post dose | Task Accuracy | 0, 300 minutes post dose | 
| Cognitive function- change in individual task Accuracy for word recognition from baseline to 300 minutes post dose | Task Accuracy | 0, 300 minutes post dose | 
| Cognitive function- change in individual task Accuracy for picture recognition from baseline to 300 minutes post dose | Task Accuracy | 0, 300 minutes post dose | 
| Cognitive function- change in individual task Accuracy for numeric working memory from baseline to 300 minutes post dose | Task Accuracy | 0, 300 minutes post dose | 
| Cognitive function- change in individual task Accuracy for choice reaction time from baseline to 300 minutes post dose | Task Accuracy | 0, 300 minutes post dose | 
| Cognitive function- change in individual task Accuracy for digit vigilance from baseline to 300 minutes post dose | Task Accuracy | 0, 300 minutes post dose | 
| Cognitive function- change in individual task Accuracy for corsi blocks task from baseline to 300 minutes post dose | Task Accuracy | 0, 300 minutes post dose | 
| Cognitive function- change in individual task Accuracy for peg and ball from baseline to 300 minutes post dose | Task Accuracy | 0, 300 minutes post dose | 
| Cognitive function- change in individual task Reaction Time for picture recognition from baseline to 300 minutes post dose | Reaction Time | 0, 300 minutes post dose | 
| Change in Reaction Time for word recognition from baseline to 300 minutes post dose Cognitive function- individual task Reaction Time for word recognition Cognitive function- individual task Reaction Time for word recognition | Reaction Time | 0, 300 minutes post dose | 
| Cognitive function- change in individual task Reaction Time for numeric working memory from baseline to 300 minutes post dose | Reaction Time | 0, 300 minutes post dose | 
| Cognitive function- change in individual task Reaction Time for choice reaction time from baseline to 300 minutes post dose | Reaction Time | 0, 300 minutes post dose | 
| Cognitive function- change in individual task Reaction Time for digit vigilance from baseline to 300 minutes post dose | Reaction Time | 0, 300 minutes post dose | 
| Cognitive function- change in individual task Reaction Time for simple reaction time from baseline to 300 minutes post dose | Reaction Time | 0, 300 minutes post dose | 
| Cognitive function- change in individual task Reaction Time for peg and ball from baseline to 300 minutes post dose | Reaction Time | 0, 300 minutes post dose | 
| Cognitive Function- change in serial 3 subtractions accuracy from baseline to 300 minutes post dose | Task accuracy | 0, 300 minutes post dose | 
| Cognitive Function- change in serial 7 subtractions accuracy from baseline to 300 minutes post dose | Task accuracy | 0, 300 minutes post dose | 
| Cognitive Function- change in Rapid Information Visual Processing accuracy from baseline to 300 minutes post dose | Task accuracy | 0, 300 minutes post dose | 
| Cognitive Function- change in Rapid Information Visual Processing reaction time from baseline to 300 minutes post dose | Reaction time | 0, 300 minutes post dose | 
| Cognitive Function- change in Rapid Information Visual Processing false alarms from baseline to 300 minutes post dose | Number of false alarms | 0, 300 minutes post dose | 
| Mental fatigue- change in subjective mental fatigue from baseline to 300 minutes post dose | Mental fatigue visual analogue scale | 0, 300 minutes post dose | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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NIRS, Cognitive Performance, Cerebral Blood Flow, Mango Leaf Extract, Zynamite®, Mangifera indica