METHODOLOGY/PRINCIPAL FINDINGS: Using a double-blind, placebo controlled, crossover design, participants (N = 24) received two doses of Panax Ginseng (500, 1000 mg) or Ginkgo Biloba (120, 240 mg) (N = 24), and underwent a series of cognitive tests while systolic, diastolic, and heart rate readings were taken. Ginkgo Biloba improved aspects of executive functioning (Stroop and Berg tasks) in females but not in males. Ginseng had no effect on cognition. Ginkgo biloba in females reversed the initial (i.e. placebo) increase in cardiovascular reactivity (systolic and diastolic readings increased compared to baseline) to cognitive tasks. This effect (reversal) was most notable after those tasks (Stroop and Iowa) that elicited the greatest cardiovascular reactivity during placebo. In males, although ginkgo also decreased cardiovascular readings, it did so from an initial (placebo) blunted response (i.e. decrease or no change from baseline) to cognitive tasks. Ginseng, on the contrary, increased cardiovascular readings compared to placebo.
CONCLUSIONS/SIGNIFICANCE: These results suggest that cardiovascular reactivity may be a mechanism by which ginkgo but not ginseng, in females is associated with certain forms of cognitive improvement.
TRIAL REGISTRATION: ClinicalTrials.gov NCT02386852.
METHODS: A randomized, double-blind, placebo-controlled trial among 35 healthy middle-aged women was performed, and subjects were randomized to receive either 250 mg PM or placebo of 100 mg maltodextrin each were taken twice daily for 6 weeks. Subjects were assessed for neuropsychological test, psychosocial status, and anthropometric at baseline, week 3, and week 6. Biomarkers were also determined at baseline and week 6.
RESULTS: The supplementation of PM showed significant intervention effect on Digit Span test (P<0.05) social functioning domain of 36-Item Short Form Health Survey (P<0.05) among subjects with mood disturbance. While, among subjects with good mood, PM supplementation improved Wechsler Abbreviated Scale of Intelligence (WASI) for IQ verbal (P=0.016) and Full Scale IQ of WASI (P=0.004). There were no adverse effects reported for the supplementation as indicated using biomarkers, including liver function and clinical symptoms.
CONCLUSION: Supplementation of PM is safe to be consumed for 6 weeks, with potential benefits to attention, short-term memory, improved quality of life, and mood, as well as IQ.
OBJECTIVE: This systematic review aimed to assess, in middle- and older-aged people, the relationship between dietary sodium intake and cognitive outcomes including cognitive function, risk of cognitive decline, or dementia.
METHODS: Six databases (PubMed, EMBASE, CINAHL, Psych info, Web of Science, and Cochrane Library) were searched from inception to 1 March 2020. Data extraction included information on study design, population characteristics, sodium reduction strategy (trials) or assessment of dietary sodium intake (observational studies), measurement of cognitive function or dementia, and summary of main results. Risk-of-bias assessments were performed using the National Heart, Lung, and Blood Institute (NHLBI) assessment tool.
RESULTS: Fifteen studies met the inclusion criteria including one clinical trial, six cohorts, and eight cross-sectional studies. Studies reported mixed associations between sodium levels and cognition. Results from the only clinical trial showed that a lower sodium intake was associated with improved cognition over six months. In analysis restricted to only high-quality studies, three out of four studies found that higher sodium intake was associated with impaired cognitive function.
CONCLUSION: There is some evidence that high salt intake is associated with poor cognition. However, findings are mixed, likely due to poor methodological quality, and heterogeneous dietary, analytical, and cognitive assessment methods and design of the studies. Reduced sodium intake may be a potential target for intervention. High quality prospective studies and clinical trials are needed.
METHODS: In this study, the effect of xanthone-enriched fraction of Garcinia mangostana (XEFGM) and α-mangostin (α-MG) were investigated on cognitive functions of the chronic cerebral hypoperfusion (CCH) rats.
KEY FINDINGS: HPLC analysis revealed that XEFGM contained 55.84% of α-MG. Acute oral administration of XEFGM (25, 50 and 100 mg/kg) and α-MG (25 and 50 mg/kg) before locomotor activity and Morris water maze (MWM) tests showed no significant difference between the groups for locomotor activity.
CONCLUSIONS: However, α-MG (50 mg/kg) and XEFGM (100 mg/kg) reversed the cognitive impairment induced by CCH in MWM test. α-MG (50 mg/kg) was further tested upon sub-acute 14-day treatment in CCH rats. Cognitive improvement was shown in MWM test but not in long-term potentiation (LTP). BDNF but not CaMKII was found to be down-regulated in CCH rats; however, both parameters were not affected by α-MG. In conclusion, α-MG ameliorated learning and memory deficits in both acute and sub-acute treatments in CCH rats by improving the spatial learning but not hippocampal LTP. Hence, α-MG may be a promising lead compound for CCH-associated neurodegenerative diseases, including vascular dementia and Alzheimer's disease.
MATERIALS AND METHODS: In this study, DET (0.625. 1.25 and 2.5 mg/kg, i.p.) was administered in rats for 21 days and those animals were challenged with single injection of LPS (250 μg/kg, i.p.) for 7 days. Cognitive and behavioral assessment was carried out for 7 days followed by molecular assessment on brain hippocampus. Statistical significance was analyzed with one-way analysis of variance followed by Dunnett's test to compare the treatment groups with the control group.
KEY FINDINGS: DET ameliorated LPS-induced neuroinflammation by suppressing major pro-inflammatory mediators such as iNOS and COX-2. Furthermore, DET enhanced the anti-inflammatory cytokines and concomitantly suppressed the pro-inflammatory cytokines and chemokine production. DET treatment also reversed LPS-induced behavioral and memory deficits and attenuated LPS-induced elevation of the expression of AD markers. DET improved synaptic-functionality via enhancing the activity of pre- and post-synaptic markers, like PSD-95 and SYP. DET also prevented LPS-induced apoptotic neurodegeneration via inhibition of PARP-1, caspase-3 and cleaved caspase-3.
SIGNIFICANCE: Overall, our studies suggest DET can prevent neuroinflammation-associated memory impairment and neurodegeneration and it could be developed as a therapeutic agent for the treatment of neuroinflammation-mediated and neurodegenerative disorders, such as AD.
METHODOLOGY: Sixty-four healthy volunteers received either a single dose (200 mg) of modafinil (n = 32) or placebo (n = 32) in a randomized, double-blind, placebo-controlled, parallel group study in which the principal outcome measures were response latencies on the response initiation and response inhibition sections of the HSCT.
PRINCIPAL FINDINGS: Participants dosed with modafinil had significantly longer mean response latencies on the HSCT for both the response initiation and response inhibition compared to participants dosed with placebo. However, participants in both groups made a similar number of errors on each of these measures, indicating that modafinil did not enhance the accuracy of performance of the task relative to placebo.
CONCLUSIONS: This study demonstrated that administration of single 200 mg doses of modafinil to healthy individuals increased the latency of responses in the performance of the HSCT, a task that is highly sensitive to prefrontal executive function, without enhancing accuracy of performance. This finding may provide important clues to defining the limitations of modafinil as a putative cognitive enhancer.
TRIAL REGISTRATION: ClinicalTrials.gov NCT02051153.
METHODS: This 12-weeks randomized, double-blind and placebo-controlled study investigated the effects of a probiotic (Lactobacillus plantarum P8; 10 log CFU daily) on psychological, memory and cognition parameters in one hundred and three (P8 n = 52, placebo n = 51) stressed adults with mean age of 31.7 ± 11.1 years old. All subjects fulfilled the criteria of moderate stress upon diagnosis using the PSS-10 questionnaire.
RESULTS: At the end of study, subjects on P8 showed reduced scores of stress (mean difference 2.94; 95% CI 0.08 to 5.73; P = 0.048), anxiety (mean difference 2.82; 95% CI 0.35 to 5.30; P = 0.031) and total score (mean difference 8.04; 95% CI 0.73 to 15.30; P = 0.041) as compared to placebo after 4-weeks, as assessed by the DASS-42 questionnaire. Although plasma cortisol levels were only marginally different between placebo and P8 (mean difference 3.28 ug/dl; 95% CI -7.09 to 0.52; P = 0.090), pro-inflammatory cytokines such as IFN-γ (mean difference 8.07 pg/ml; 95% CI -11.2 to -4.93; P