Natural products and supplements for geriatric depression and cognitive disorders: an evaluation of the research

Rationale for a Multi-Factorial Approach for the Reversal of Cognitive Decline in Alzheimer's Disease and MCI: A Review

Alzheimer's disease (AD) is a multifactorial, progressive, neurodegenerative disease typically characterized by memory loss, personality changes, and a decline in overall cognitive function. Usually manifesting in individuals over the age of 60, this is the most prevalent type of dementia and remains the fifth leading cause of death among Americans aged 65 and older. While the development of effective treatment and prevention for AD is a major healthcare goal, unfortunately, therapeutic approaches to date have yet to find a treatment plan that produces long-term cognitive improvement. Drugs that may be able to slow down the progression rate of AD are being introduced to the market; however, there has been no previous solution for preventing or reversing the disease-associated cognitive decline. Recent studies have identified several factors that contribute to the progression and severity of the disease: diet, lifestyle, stress, sleep, nutrient deficiencies, mental health, socialization, and toxins. Thus, increasing evidence supports dietary and other lifestyle changes as potentially effective ways to prevent, slow, or reverse AD progression. Studies also have demonstrated that a personalized, multi-therapeutic approach is needed to improve metabolic abnormalities and AD-associated cognitive decline. These studies suggest the effects of abnormalities, such as insulin resistance, chronic inflammation, hypovitaminosis D, hormonal deficiencies, and hyperhomocysteinemia, in the AD process. Therefore a personalized, multi-therapeutic program based on an individual's genetics and biochemistry may be preferable over a single-drug/mono-therapeutic approach. This article reviews these multi-therapeutic strategies that identify and attenuate all the risk factors specific to each affected individual. This article systematically reviews studies that have incorporated multiple strategies that target numerous factors simultaneously to reverse or treat cognitive decline. We included high-quality clinical trials and observational studies that focused on the cognitive effects of programs comprising lifestyle, physical, and mental activity, as well as nutritional aspects. Articles from PubMed Central, Scopus, and Google Scholar databases were collected, and abstracts were reviewed for relevance to the subject matter. Epidemiological, pathological, toxicological, genetic, and biochemical studies have all concluded that AD represents a complex network insufficiency. The research studies explored in this manuscript confirm the need for a multifactorial approach to target the various risk factors of AD. A single-drug approach may delay the progression of memory loss but, to date, has not prevented or reversed it. Diet, physical activity, sleep, stress, and environment all contribute to the progression of the disease, and, therefore, a multi-factorial optimization of network support and function offers a rational therapeutic strategy. Thus, a multi-therapeutic program that simultaneously targets multiple factors underlying the AD network may be more effective than a mono-therapeutic approach.

Translational Informatics for Natural Products as Antidepressant Agents

Depression, a neurological disorder, is a universally common and debilitating illness where social and economic issues could also become one of its etiologic factors. From a global perspective, it is the fourth leading cause of long-term disability in human beings. For centuries, natural products have proven their true potential to combat various diseases and disorders, including depression and its associated ailments. Translational informatics applies informatics models at molecular, imaging, individual, and population levels to promote the translation of basic research to clinical applications. The present review summarizes natural-antidepressant-based translational informatics studies and addresses challenges and opportunities for future research in the field.

Improvement of cognitive performance by a nutraceutical formulation: Underlying mechanisms revealed by laboratory studies

Cognitive decline, decrease in neuronal function and neuronal loss that accompany normal aging and dementia are the result of multiple mechanisms, many of which involve oxidative stress. Herein, we review these various mechanisms and identify pharmacological and non-pharmacological approaches, including modification of diet, that may reduce the risk and progression of cognitive decline. The optimal degree of neuronal protection is derived by combinations of, rather than individual, compounds. Compounds that provide antioxidant protection are particularly effective at delaying or improving cognitive performance in the early stages of Mild Cognitive Impairment and Alzheimer's disease. Laboratory studies confirm alleviation of oxidative damage in brain tissue. Lifestyle modifications show a degree of efficacy and may augment pharmacological approaches. Unfortunately, oxidative damage and resultant accumulation of biomarkers of neuronal damage can precede cognitive decline by years to decades. This underscores the importance of optimization of dietary enrichment, antioxidant supplementation and other lifestyle modifications during aging even for individuals who are cognitively intact.

A systems pharmacology approach to identify the autophagy-inducing effects of Traditional Persian medicinal plants

Aging is correlated with several complex diseases, including type 2 diabetes, neurodegeneration diseases, and cancer. Identifying the nature of this correlation and treatment of age-related diseases has been a major subject of both modern and traditional medicine. Traditional Persian Medicine (TPM) embodies many prescriptions for the treatment of ARDs. Given that autophagy plays a critical role in antiaging processes, the present study aimed to examine whether the documented effect of plants used in TPM might be relevant to the induction of autophagy? To this end, the TPM-based medicinal herbs used in the treatment of the ARDs were identified from modern and traditional references. The known phytochemicals of these plants were then examined against literature for evidence of having autophagy inducing effects. As a result, several plants were identified to have multiple active ingredients, which indeed regulate the autophagy or its upstream pathways. In addition, gene set enrichment analysis of the identified targets confirmed the collective contribution of the identified targets in autophagy regulating processes. Also, the protein-protein interaction (PPI) network of the targets was reconstructed. Network centrality analysis of the PPI network identified mTOR as the key network hub. Given the well-documented role of mTOR in inhibiting autophagy, our results hence support the hypothesis that the antiaging mechanism of TPM-based medicines might involve autophagy induction. Chemoinformatics study of the phytochemicals using docking and molecular dynamics simulation identified, among other compounds, the cyclo-trijuglone of Juglans regia L. as a potential ATP-competitive inhibitor of mTOR. Our results hence, provide a basis for the study of TPM-based prescriptions using modern tools in the quest for developing synergistic therapies for ARDs.

Phenol glycosides extract of Fructus Ligustri Lucidi attenuated depressive-like behaviors by suppressing neuroinflammation in hypothalamus of mice

Depression is partially caused by inflammation in central nervous system. This study investigated the ameliorative effects of phenol glycosides (PG) from Ligustrum lucidum Ait. (Oleaceae) on neuroinflammation and depressive-like behavior in mice hypothalamus as well as the molecular mechanism. Mice were administered with PG extract for 2 weeks prior to treatment with LPS. The mice treated with PG extract showed resistance to LPS-induced reduction in body weight and LPS-induced depressive-like behaviors shown by sucrose preference, tail suspension test, forced swimming test and open field test. LPS-induced activation of microglial cells and elevation in protein expression of inflammatory cytokines including IL-1β, RANTES and MCP-1 in hypothalamus of mice were abrogated by pre-treatment with PG extract. This extract down-regulated expression of TLR4, MyD88, NLRP3, renin and angiotensin II and decreased proportional area of Iba-1⁺ microglias in hypothalamus. Pre-treatment with PG extract inhibited LPS-triggered activation of CaSR/G_α11 signaling, stimulated 1-OHase expression in hypothalamus, and enhanced circulating 1,25(OH)₂ D₃ level. Overall, pre-treatment with PG extract ameliorated LPS-induced depressive-like behaviors by repressing neuroinflammation in mice hypothalamus which was attributed to its suppression on activation of microglia and production of inflammatory cytokines via acting on TLR4 pathway, CaSR and RAS cascade associated with improving vitamin D metabolism.

Depression in the Elderly. Consensus Statement of the Spanish Psychogeriatric Association

INTRODUCTION

Present knowledge about depression in the elderly is still scarce and often controversial, despite its high frequency and impact. This article reports the results and most relevant conclusions of a Delphi-based consensus on geriatric depression promoted by the Spanish Psychogeriatric Association.

METHODS

A 78-item questionnaire was developed by 7 highly specialized geriatric psychiatrists and was evaluated using the Modified Delphi technique in two rounds answered by 35 psychiatrists with an extensive expertise in geriatric depression. The topics and number of questions (in brackets) covered were: concepts, clinical aspects, and risk factors (12); screening and diagnosis (7); psychotic depression (17); depression and dementia (5); antidepressant drug treatment (18); non-pharmacological biological treatments (5); psychotherapeutic treatments (4); comorbidity and preventive aspects (6); professional training needed (4). In addition, the expert panel's opinion on the antidepressants of choice in 21 common comorbid conditions and on different strategies to approach treatment-resistant cases in terms of both efficacy and safety was assessed.

RESULTS

After the two rounds of the Delphi process, consensus was reached for 59 (75.6%) of the 78 items. Detailed recommendations are included in the text. Considering pharmacological treatments, agomelatine was the most widely mentioned drug to be recommended in terms of safety in comorbid conditions. Desvenlafaxine, sertraline, and vortioxetine, were the most frequently recommended antidepressants in comorbid conditions in general. Combining parameters of efficacy and safety, experts recommended the following steps to address cases of treatment resistance: 1. Escalation to the maximum tolerated dose; 2. Change of antidepressant; 3. Combination with another antidepressant; 4. Potentiation with an antipsychotic or with lamotrigine; 5. Potentiation with lithium; 6. Potentiation with dopamine agonists or methylphenidate.

DISCUSSION AND CONCLUSIONS

Consensus was reached for a high number of items as well as for the management of depression in the context of comorbid conditions and in resistant cases. In the current absence of sufficient evidence-based information, our results can be used to inform medical doctors about clinical recommendations that might reduce uncertainty in the diagnosis and treatment of elderly patients with depressive disorders.

Diet and Neurocognition in Mood Disorders - An Overview of the Overlooked

Bipolar disorder and major depression are associated with significant disability, morbidity, and reduced life expectancy. People with mood disorders have shown higher ratios of unhealthy lifestyle choices, including poor diet quality and suboptimal nutrition. Diet and nutrition impact on brain /mental health, but cognitive outcomes have been less researched in psychiatric disorders. Neurocognitive dysfunction is a major driver of social dysfunction and a therapeutic target in mood disorders, although effective cognitive-enhancers are currently lacking. This narrative review aimed to assess the potential cognitive benefits of dietary and nutritional interventions in subjects diagnosed with mood disorders. Eight clinical trials with nutrients were identified, whereas none involved dietary interventions. Efficacy to improve select cognitive deficits has been reported, but results are either preliminary or inconsistent. Methodological recommendations for future cognition trials in the field are advanced. Current evidence and future views are discussed from the perspectives of precision medicine, clinical staging, nutritional psychiatry, and the brain-gut-microbiota axis.

Neurotrophic function of phytochemicals for neuroprotection in aging and neurodegenerative disorders: modulation of intracellular signaling and gene expression

Bioactive compounds in food and beverages have been reported to promote health and prevent age-associated decline in cognitive, motor and sensory activities, and emotional function. Phytochemicals, a ubiquitous class of plant secondary metabolites, protect neuronal cells by interaction with cellular activities, in addition to the antioxidant and anti-inflammatory function. In aging and age-associated neurodegenerative disorders, phytochemicals protect neuronal cells by neurotrophic factor-mimic activity, in addition to suppression of apoptosis signaling in mitochondria. This review presents the cellular mechanisms underlying anti-apoptotic function and neurotrophic function of phytochemicals in the brain. Phytochemicals bind to receptors of neurotrophic factors, and also receptors for γ-aminobutyric acid, acetylcholine, serotonin, and glutamate and estrogen, and activate downstream signal pathways. Phytochemicals also directly intervene intracellular signaling molecules to modify the brain function. Finally, phytochemicals enhance the endogenous biosynthesis of genes coding anti-apoptotic Bcl-2 and neurotrophic factors, such as brain-derived and glial cell line-derived neurotrophic factor. The gene induction may play a major role in the neuroprotective function of dietary compounds shown by epidemiological studies. Quantitative measurement of neurotrophic factors induced by phytochemicals in the serum, cerebrospinal fluid, and other clinical samples is proposed as a surrogate assay method to evaluate the neuroprotective potency. Development of novel neuroprotective compounds is expected among compounds chemically synthesized from the brain-permeable basic structure of phytochemicals.

Effects of Omega-3 Fatty Acid Supplementation on Cognitive Functions and Neural Substrates: A Voxel-Based Morphometry Study in Aged Mice

Human and experimental studies have revealed putative neuroprotective and pro-cognitive effects of omega-3 polyunsaturated fatty acids (n-3 PUFA) in aging, evidencing positive correlations between peripheral n-3 PUFA levels and regional grey matter (GM) volume, as well as negative correlations between dietary n-3 PUFA levels and cognitive deficits. We recently showed that n-3 PUFA supplemented aged mice exhibit better hippocampal-dependent mnesic functions, along with enhanced cellular plasticity and reduced neurodegeneration, thus supporting a role of n-3 PUFA supplementation in preventing cognitive decline during aging. To corroborate these initial results and develop new evidence on the effects of n-3 PUFA supplementation on brain substrates at macro-scale level, here we expanded behavioral analyses to the emotional domain (anxiety and coping skills), and carried out a fine-grained regional GM volumetric mapping by using high-resolution MRI-based voxel-based morphometry. The behavioral effects of 8 week n-3 PUFA supplementation were measured on cognitive (discriminative, spatial and social) and emotional (anxiety and coping) abilities of aged (19 month-old at the onset of study) C57B6/J mice. n-3 PUFA supplemented mice showed better mnesic performances as well as increased active coping skills. Importantly, these effects were associated with enlarged regional hippocampal, retrosplenial and prefrontal GM volumes, and with increased post mortem n-3 PUFA brain levels. These findings indicate that increased dietary n-3 PUFA intake in normal aging can improve fronto-hippocampal GM structure and function, an effect present also when the supplementation starts at late age. Our data are consistent with a protective role of n-3 PUFA supplementation in counteracting cognitive decline, emotional dysfunctions and brain atrophy.

Hot Topics in Research: Preventive Neuroradiology in Brain Aging and Cognitive Decline

Preventive neuroradiology is a new concept supported by growing literature. The main rationale of preventive neuroradiology is the application of multimodal brain imaging toward early and subclinical detection of brain disease and subsequent preventive actions through identification of modifiable risk factors. An insightful example of this is in the area of age-related cognitive decline, mild cognitive impairment, and dementia with potentially modifiable risk factors such as obesity, diet, sleep, hypertension, diabetes, depression, supplementation, smoking, and physical activity. In studying this link between lifestyle and cognitive decline, brain imaging markers may be instrumental as quantitative measures or even indicators of early disease. The purpose of this article is to provide an overview of the major studies reflecting how lifestyle factors affect the brain and cognition aging. In this hot topics review, we will specifically focus on obesity and physical activity.

Clinical Advances in Geriatric Psychiatry: A Focus on Prevention of Mood and Cognitive Disorders

The world population is aging at a rate unprecedented in human history, placing substantial pressure on health systems across the world along with concurrent rises in chronic diseases. In particular, rates of cognitive disorders and late-life affective disorders are expected to increase. In tandem with aging, there are robust predictions suggesting that rates of age-related cognitive decline and dementia, and geriatric depression, will increase, with serious consequences. Clearly innovative prevention and treatment strategies are needed. This article reviews the latest promising clinical advances that hold promise for assisting the prevention and treatment of depression, cognitive decline, and dementia.