scholarly journals The Acute and Chronic Cognitive and Cerebral Blood Flow Effects of a Sideritis scardica (Greek Mountain Tea) Extract: A Double Blind, Randomized, Placebo Controlled, Parallel Groups Study in Healthy Humans

Nutrients ◽  
2018 ◽  
Vol 10 (8) ◽  
pp. 955 ◽  
Author(s):  
Emma Wightman ◽  
Philippa Jackson ◽  
Julie Khan ◽  
Joanne Forster ◽  
Felix Heiner ◽  
...  

Background: The presence of polyphenols such as hydroxy-cinnamic acids and flavonoids in Sideritis scardica (Greek mountain tea) are likely responsible for the cognitive and mood effects of its consumption and this could be underpinned by the ability of such polyphenols to prevent monoamine neurotransmitter reuptake and to increase cerebral blood flow (CBF). Objective: The current study extends the small amount of Sideritis scardica literature in humans by assessing both cognitive and mood outcomes in a sample of older adults, as well as blood pressure (BP) and CBF, in a subsample, utilizing near-infrared spectroscopy (NIRS). Design: This randomized, double-blind, placebo-controlled, parallel groups trial randomized N = 155, 50–70-year-old male and female participants who were assessed for the cognitive (N = 140), mood (N = 142), BP (N = 133) and CBF (N = 57) effects of two doses of Greek mountain tea (475 and 950 mg) as well as an active control of 240 mg Ginkgo biloba, and a placebo control, following acute consumption (Day 1) and following a month-long consumption period (Day 28). Results: Relative to the placebo control, 950 mg Greek mountain tea evinced significantly fewer false alarms on the Rapid Visual Information Processing (RVIP) task on Day 28 and significantly reduced state anxiety following 28 days consumption (relative also to the active, Ginkgo control). This higher dose of Greek mountain tea also attenuated a reduction in accuracy on the picture recognition task, on Day 1 and Day 28, relative to Ginkgo and both doses of Greek mountain tea trended towards significantly faster speed of attention on both days, relative to Ginkgo. Both doses of Greek mountain tea, relative to placebo, increased oxygenated haemoglobin (HbO) and oxygen saturation (Ox%) in the prefrontal cortex during completion of cognitively demanding tasks on Day 1. The higher dose also evinced greater levels of total (THb) and deoxygenated (Hb) haemoglobin on Day 1 but no additional effects were seen on CBF on Day 28 following either dose of Greek mountain tea. Ginkgo biloba led to lower levels of Ox% and higher levels of Hb on Day 1 and lower levels of both HbO and THb on Day 28. Conclusions: The significantly improved cognitive performance following Greek mountain tea on Day 1 could be due to significant modulation of the CBF response. However, these improvements on Day 28 are more likely to be due to the reductions in state anxiety and, taken together, suggests that the former mechanism is more likely to facilitate acute cognitive effects and the latter more likely to underpin more prolonged cognitive improvements.

Nutrients ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 3022 ◽  
Author(s):  
David Kennedy ◽  
Emma Wightman ◽  
Julie Khan ◽  
Torsten Grothe ◽  
Philippa Jackson

Background: Zanthoxylum armatum DC. (ZA) is a traditional Asian culinary spice and medicinal compound, which is rich in monoterpenes and hydroxy α-sanshool. Mechanistic interactions with the monoamine, cholinergic and cannabinoid neurotransmission systems, as well as transient receptor potential (TRP) and potassium ion channels, may predispose ZA to modulate human brain function. Objectives: To investigate the effects of a single dose and 56-days supplementation with a lipid extract of ZA on cognitive function, mood and cerebral blood-flow (CBF) parameters in the pre-frontal cortex during cognitive task performance. Design: Double-blind, randomized, parallel groups study with N = 82 healthy males and females between the ages of 30 and 55 years. Assessments were undertaken pre-dose and at 1, 3 and 5 h post-dose on the first (Day 1) and last (Day 56) days of supplementation. Results: A single dose of ZA (Day 1) resulted in acute improvements on a ‘Speed of Attention’ factor and the Rapid Visual Information Processing (RVIP) task, in comparison to placebo. However, following ZA participants were less accurate on the name-to-face recall task. After 56 days of ZA consumption (Day 56), speed was enhanced on a global ‘Speed of Performance’ measure, comprising data from all of the timed tasks in the computerized battery. Participants also completed more correct Serial 3s Subtractions at the 3 h assessment and were less mentally fatigued throughout the day than participants consuming placebo. These effects were complemented on both Day 1 and Day 56 by modulation of CBF parameters, as assessed by Near Infrared Spectroscopy (NIRS). The primary finding here was a reduced hemodynamic response during the RVIP task. Conclusion: ZA improves aspects of cognitive performance, in particular the speed of performing tasks, in healthy humans and results in concomitant reductions in hemodynamic responses in the frontal cortex during task performance. The findings suggest an increase in neural efficiency following ZA.


2016 ◽  
Vol 41 (12) ◽  
pp. 1225-1232 ◽  
Author(s):  
Lieselot Decroix ◽  
Cajsa Tonoli ◽  
Danusa D. Soares ◽  
Semah Tagougui ◽  
Elsa Heyman ◽  
...  

Acute exercise-induced improvements in cognitive function are accompanied by increased (cerebral) blood flow and increased brain-derived neurotrophic factor (BDNF) levels. Acute cocoa flavanol (CF) intake may improve cognitive function, cerebral blood flow (in humans), and BNDF levels (in animals). This study investigated (i) the effect of CF intake in combination with exercise on cognitive function and (ii) cerebral hemodynamics and BDNF in response to CF intake and exercise. Twelve healthy men participated in this randomized, double-blind, crossover study. Participants performed a cognitive task (CT) at 100 min after acute 903-mg CF or placebo (PL) intake, followed by a 30-min time-trial. Immediately after this exercise, the same CT was performed. Prefrontal near-infrared spectroscopy was applied during CT and exercise to measure changes in oxygenated (ΔHbO2), deoxygenated (ΔHHb), and total haemoglobin (ΔHbtot) and blood samples were drawn and analyzed for BDNF. Reaction time was faster postexercise, but was not influenced by CF. ΔHbO2 during the resting CT was increased by CF, compared with PL. ΔHbO2, ΔHHb, and ΔHbtot increased in response to exercise without any effect of CF. During the postexercise cognitive task, there were no hemodynamic differences between CF or PL. Serum BDNF was increased by exercise, but was not influenced by CF. In conclusion, at rest, CF intake increased cerebral oxygenation, but not BDNF concentrations, and no impact on executive function was detected. This beneficial effect of CF on cerebral oxygenation at rest was overruled by the strong exercise-induced increases in cerebral perfusion and oxygenation.


2015 ◽  
Vol 114 (9) ◽  
pp. 1427-1437 ◽  
Author(s):  
Emma L. Wightman ◽  
Crystal F. Haskell-Ramsay ◽  
Jonathon L. Reay ◽  
Gary Williamson ◽  
Tristan Dew ◽  
...  

AbstractSingle doses of resveratrol have previously been shown to increase cerebral blood flow (CBF) with no clear effect on cognitive function or mood in healthy adults. Chronic resveratrol consumption may increase the poor bioavailability of resveratrol or otherwise potentiate its psychological effects. In this randomised, double-blind, placebo-controlled, parallel-groups study, a total of sixty adults aged between 18 and 30 years received either placebo or resveratrol for 28 d. On the 1st and 28th day of treatment, the performance of cognitively demanding tasks (serial subtractions, rapid visual information processing and 3-Back) (n 41 complete data sets) was assessed, alongside blood pressure (n 26) and acute (near-IR spectroscopy (NIRS)) and chronic (transcranial Doppler) measures of CBF (n 46). Subjective mood, sleep quality and health questionnaires were completed at weekly intervals (n 53/54). The results showed that the cognitive effects of resveratrol on day 1 were restricted to more accurate but slower serial subtraction task performance. The only cognitive finding on day 28 was a beneficial effect of resveratrol on the accuracy of the 3-Back task before treatment consumption. Subjective ratings of ‘fatigue’ were significantly lower across the entire 28 d in the resveratrol condition. Resveratrol also resulted in modulation of CBF parameters on day 1, as assessed by NIRS, and significantly increased diastolic blood pressure on day 28. Levels of resveratrol metabolites were significantly higher both before and after the day’s treatment on day 28, in comparison with day 1. These results confirm the acute CBF effects of resveratrol and the lack of interpretable cognitive effects.


PEDIATRICS ◽  
1987 ◽  
Vol 79 (2) ◽  
pp. 315-315
Author(s):  
KARL C. K. KUBAN ◽  
ELIZABETH BROWN ◽  
ALAN LEVITON ◽  
KALPATHY KRISHNAMOORTHY

In Reply.— We appreciate the comments by Dr Battisti et al. As noted in the inclusion criteria for our study,1 all intubated babies with birth weights less than 1,751 g were eligible for the study. One of the advantages of a randomized double-blind study is that babies with other risk factors, including presence of a fluctuating cerebral blood flow pattern on Doppler ultrasound testing, should have equal chances of being in the treated and placebo groups.


2006 ◽  
Vol 100 (3) ◽  
pp. 850-857 ◽  
Author(s):  
Kenneth M. Tichauer ◽  
Derek W. Brown ◽  
Jennifer Hadway ◽  
Ting-Yim Lee ◽  
Keith St. Lawrence

Impaired oxidative metabolism following hypoxia-ischemia (HI) is believed to be an early indicator of delayed brain injury. The cerebral metabolic rate of oxygen (CMRO2) can be measured by combining near-infrared spectroscopy (NIRS) measurements of cerebral blood flow (CBF) and cerebral deoxy-hemoglobin concentration. The ability of NIRS to measure changes in CMRO2 following HI was investigated in newborn piglets. Nine piglets were subjected to 30 min of HI by occluding both carotid arteries and reducing the fraction of inspired oxygen to 8%. An additional nine piglets served as sham-operated controls. Measurements of CBF, oxygen extraction fraction (OEF), and CMRO2 were obtained at baseline and at 6 h after the HI insult. Of the three parameters, only CMRO2 showed a persistent and significant change after HI. Five minutes after reoxygenation, there was a 28 ± 12% (mean ± SE) decrease in CMRO2, a 72 ± 50% increase in CBF, and a 56 ± 19% decrease in OEF compared with baseline ( P < 0.05). By 30 min postinsult and for the remainder of the study, there were no significant differences in CBF and OEF between control and insult groups, whereas CMRO2 remained depressed throughout the 6-h postinsult period. This study demonstrates that NIRS can measure decreases in CMRO2 caused by HI. The results highlight the potential for NIRS to be used in the neonatal intensive care unit to detect delayed brain damage.


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