[Prevention of suicide of the elderly in France. To a multimodal strategy against depression and isolation: CQFDi]

Luteolin Enhances Choroid Plexus 5-MTHF Brain Transport to Promote Hippocampal Neurogenesis in LOD Rats

Folates, provided by food, are commonly used antidepressant synergists in late-onset depression (LOD). However, increased intake of folic acid in the elderly population might lead to the accumulation of unmetabolized folic acid in the systemic circulation, leading to enhanced deterioration of the central nervous system function. In addition, folates cannot access the brain directly because of the blood-brain barrier. Choroid plexus (CP) 5-methyltetrahydrofolate (5-MTHF) brain transport plays a critical role in regulating the cerebrospinal fluid (CSF) 5-MTHF content. Luteolin is a natural flavonoid that has antidepressant effects and is involved in the anti-folate resistance pathway. It remains unclear whether the antidepressant effects of luteolin are associated with the CP 5-MTHF brain transport. In this study, 20-21-month-old Wistar rats were exposed to the chronic unpredictable mild stress (CUMS) protocol for 6 consecutive weeks to explore the long-term effects of luteolin on behavior, 5-MTHF levels, hippocampal neurogenesis, and folate brain transport of the CP. In vitro primary hippocampal neural stem cells (NSCs) cultured in media containing 10% CSF from each group of rats and choroid plexus epithelial cells (CPECs) cultured in media containing 20 μM luteolin were treated with 100 μM corticosterone and 40 mg/ml D-galactose. We found that aged rats exposed to CUMS showed a significantly reduced sucrose preference, decreased locomotion activity in the open field test and accuracy of the Morris water maze test, increased immobility time in the forced swimming test, accelerated dysfunctional neurogenesis and neuronal loss in the dentate gyrus of LOD rats, as well as decreased CSF and hippocampus 5-MTHF levels, and zona occludens protein 1 (ZO-1), proton-coupled folate transporter (PCFT), and reduced folate carrier (RFC) protein levels. In vitro assays showed media containing 10% aged CSF or LOD+ Luteolin-CSF significantly increased the viability of CORT + D-gal-injured NSCs and alleviated dysfunctional neurogenesis and neuronal loss compared with the CORT + D-gal medium. However, media containing 10% LOD-CSF had no such effect. In the meantime, induction of CORT + D-gal significantly decreased the ZO-1, PCFT, RFC, and folate receptor alpha (FR-α) protein levels and transepithelial electrical resistance in rat CPECs. As expected, luteolin treatment was effective in improving these abnormal changes. These findings suggested that luteolin could ameliorate CUMS-induced LOD-like behaviors by enhancing the folate brain transport.

Prevention of suicidal behavior in older people: A systematic review of reviews

Older people have the highest rates of suicide, yet the evidence base on effective suicide preventions in late-life is limited. This systematic review of reviews aims to synthesize data from existing reviews on the prevention and/or reduction of suicide behavior in late-life and evidence for effectiveness of interventions. A systematic database search was conducted in eight electronic databases from inception to 4/2020 for reviews targeting interventions among adults ≥ 60 to prevent and/or reduce suicide, suicide attempt, self-harm and suicidal ideation. Four high quality reviews were included and interventions categorized as pharmacological (antidepressant use: 239 RCTs, seven observational studies) and behavioral (physical activity: three observational studies, and multifaceted primary-care-based collaborative care for depression screening and management: four RCTs). The 2009 antidepressant use review found significant risk reduction for suicide attempt/self-harm (OR = 0.06, 95% CI 0.01-0.58) and suicide ideation (OR = 0.39, 95% CI 0.18-0.78) versus placebo. The 2015 review found an increased risk of attempts with antidepressants versus no treatment (RR = 1.18, 95% CI 1.10-1.27) and no statistically significant change in suicides versus no treatment (RR = 1.06, 95% CI 0.68-1.66) or ideation versus placebo (OR = 0.52, 95% CI 0.14-1.94). Protective effects were found for physical activity on ideation in 2 out of 3 studies when comparing active versus inactive older people. Collaborative care demonstrated significantly less attempts/ideation (OR = 0.80, 95% CI 0.68-0.94) in intervention group versus usual care. The results of this review of reviews find the evidence inconclusive towards use of antidepressants for the prevention of suicidal behavior in older people, thus monitoring is required prior to start, dosage change or cessation of antidepressants. Evidence to date supports physical activity and collaborative management for reduction of suicide ideation, but additional trials are required for a meta-analysis. To build on these findings, continued high-quality research is warranted to evaluate the effectiveness of interventions in late life.