The role of resveratrol in neurogenesis: a systematic review

Exploring the therapeutic role of Moringa oleifera in neurodegeneration: antioxidant, anti-inflammatory, and neuroprotective mechanisms

Neurodegenerative disorders like Alzheimer's disease, Parkinson's disease, and other cognitive impairment conditions in elderly are defined by progressive loss of neurons, based mostly on oxidative stress, long-term neuroinflammation, and compromised neuroplasticity. In the midst of increasing investigation for natural drugs, Moringa oleifera, a plant highly accepted for its high nutritional and phytochemical constitution, has become an active candidate with multi-oriented neuroprotective activity. This review discusses the therapeutic potential of Moringa oleifera in neurodegeneration, based on its antioxidant, anti-inflammatory, and neuroprotective activities. The plant's bioactive molecules, flavonoids, phenolic acids, and vitamins exhibit potent free radical-scavenging activity and the ability to modulate crucial inflammatory signaling pathways, like NF-κB and MAPK signaling. Additionally, Moringa oleifera is shown to possess the potential for enhancing neurogenesis, facilitating synaptic plasticity, and neuronal apoptosis protection. Preclinical evidence supports its efficacy in decreasing neuropathological alterations and enhancing cognitive function, whereas initial clinical data suggest a benign safety profile. In spite of these promising observations, additional work is required to confirm its action in human subjects and to standardize therapeutic regimens. This review highlights the promise of Moringa oleifera as an adjunct treatment for the prevention and management of neurodegenerative disorders and points to avenues for future investigation and clinical utility.

Therapeutic effects of resveratrol on memory deficits in offspring of sleep-deprived rats: Involvement of hippocampal BDNF-TrkB pathways

BACKGROUND

Maternal sleep deprivation (MSD) is a significant public health issue that adversely affects neurogenesis and synaptic plasticity in offspring, resulting in cognitive deficits in learning and memory. Resveratrol, an antioxidant with neuroprotective and anti-inflammatory properties, may help mitigate these effects. This study investigates resveratrol's potential to counteract the negative impacts of MSD on neurodevelopment in male Wistar rat offspring.

METHODS

Ninety-six male Wistar rat offspring and 36 pregnant rats were used. Total MSD was induced using the water box device on gestational days 7, 11, and 17. Pregnant rats received resveratrol at doses of 25 or 50 mg/kg every 12 h during the sleep deprivation period. After parturition, offspring were divided into 12 groups for assessment at two months of age. Social interaction tests evaluated social memory, while the Morris water maze test assessed spatial learning and memory. Brain samples were prepared for Nissl staining, and brain-derived neurotrophic factor (BDNF) and tyrosine-protein kinase (TrkB) expression levels in the hippocampus were measured using western blotting.

RESULTS

Our findings indicate that the MSD group exhibited decreased BDNF/TrkB expression and increased neuronal damage in the hippocampus, which led to disrupted spatial and social memory compared to the control group. Subsequently, resveratrol administration, especially at a dose of 50 mg/kg during pregnancy, significantly reversed MSD's detrimental effects on cognitive function in offspring.

CONCLUSION

Our results provide novel evidence of resveratrol's neuroprotective effects in rat pregnancy models of MSD, suggesting its potential for developing therapeutic interventions targeting prenatal neurodegenerative disorders.

Plasma tryptophan levels are linked to hippocampal integrity and cognitive function in individuals with mild cognitive impairment

Tryptophan has been shown to improve cognitive functions, but whether these benefits emanate from changes in hippocampal structure or other mechanisms like enhanced serotonin pathways remains unclear. This study aimed to examine the relationship between tryptophan levels and hippocampal volumes in individuals with mild cognitive impairment (MCI) and to determine if changes in hippocampal volume correlate with cognitive function. A total of 499 individuals with MCI were recruited based on ADNI's clinical criteria. Cognitive function was assessed using the ADAS-Cog scale, and hippocampal volumes were measured through MRI using semi-automated Medtronic Surgical Navigation Technologies (SNT). Tryptophan levels in plasma were analyzed using a nuclear magnetic resonance (NMR)-based assay. This study used two models: One unadjusted and another adjusted for covariates such as age, gender, handedness, and ApoE ɛ3 and ɛ4. In both models, higher tryptophan levels were significantly associated with increased bilateral hippocampal volumes, with a stronger effect in the left hippocampus. Furthermore, larger hippocampal volumes were linked to improved cognitive performance. Mediation analysis showed that hippocampal volumes mediated the relationship between plasma tryptophan levels and cognitive function. These findings suggested that elevated plasma tryptophan levels support cognitive health by maintaining hippocampal structural integrity, underscoring its potential role in preserving cognitive function in individuals with MCI.

Serotonin enhances neurogenesis biomarkers, hippocampal volumes, and cognitive functions in Alzheimer's disease

Research on serotonin reveals a lack of consensus regarding its role in brain volume, especially concerning biomarkers linked to neurogenesis and neuroplasticity, such as ciliary neurotrophic factor (CNTF), fibroblast growth factor 4 (FGF-4), bone morphogenetic protein 6 (BMP-6), and matrix metalloproteinase-1 (MMP-1) in Alzheimer's disease (AD). This study aimed to investigate the influence of serotonin on brain structure and hippocampal volumes in relation to cognitive functions in AD, as well as its link with biomarkers like CNTF, FGF-4, BMP-6, and MMP-1. Data from 133 ADNI participants with AD included cognitive assessments (CDR-SB), serotonin measurements (Biocrates AbsoluteIDQ p180 kit, UPLC-MS/MS), and neurotrophic factors quantified via multiplex proteomics. Gray matter volume changes were analyzed using Voxel-Based Morphometry (VBM) with MRI. Statistical analyses employed Pearson correlation, bootstrap methods, and FDR-adjusted p-values (< 0.05 or < 0.01) via the Benjamini-Hochberg procedure, alongside nonparametric methods. The analysis found a positive correlation between serotonin levels and total brain (r = 0.229, p = 0.023) and hippocampal volumes (right: r = 0.186, p = 0.032; left: r = 0.210, p = 0.023), even after FDR adjustment. Higher serotonin levels were linked to better cognitive function (negative correlation with CDR-SB, r = -0.230, p = 0.024). Notably, serotonin levels were positively correlated with BMP-6 (r = 0.173, p = 0.047), CNTF (r = 0.216, p = 0.013), FGF-4 (r = 0.176, p = 0.043), and MMP-1 (r = 0.202, p = 0.019), suggesting a link between serotonin and neurogenesis and neuroplasticity. However, after adjusting for multiple comparisons and controlling for confounding factors such as age, gender, education, and APOE genotypes (APOE3 and APOE4), none of the correlations of biomarkers remained statistically significant. In conclusion, increased serotonin levels are associated with improved cognitive function and increased brain volume. However, associations with CNTF, FGF-4, BMP-6, and MMP-1 were not statistically significant after adjustments, highlighting the complexity of serotonin's role in AD and the need for further research.