Genistein and Galantamine Combinations Decrease β-Amyloid Peptide (1-42)-Induced Genotoxicity and Cell Death in SH-SY5Y Cell Line: an In Vitro and In Silico Approach for Mimic of Alzheimer's Disease

[Antigenotoxicity of the soy isoflavone genistein in mice exposed to carcinogenic hexavalent chromium compounds]

Introduction

Introduction: the consumption of antioxidant-rich foods such as soy isoflavones may be an alternative in the protection and modulation against metal-induced genotoxicity with carcinogenic potential associated with oxidative stress. Objective: to evaluate the antigenotoxic effects of soy isoflavone genistein in mice exposed to carcinogenic compounds of hexavalent chromium (Cr[VI]). Material and method: twenty-five male Hsd:ICR mice were divided into five groups treated as follows: a) vehicle 1 (sterile distilled water, intraperitoneally); b) vehicle 2 (corn oil for fat-soluble compounds, orally); c) 15 mg/kg of genistein, orally; d) 20 mg/kg of CrO3, intraperitoneally; and e) 15 mg/kg of genistein four hours before the application of 20 mg/kg of CrO3. Evaluations of micronuclei (MN), apoptosis, ratio of polychromatic/normochromatic erythrocytes (EPC/ENC) and cell viability in peripheral blood obtained at 0, 24, 48 and 72 hours were performed. Results: the treatment with genistein reduced MN when administered prior to treatment with CrO3, the effect being greater at 48 hours (reduction of 84 %). Cell viability was reduced with genistein and CrO3 treatments alone, the effect being greater in the latter. Conclusions: genistein effectively blocked the genotoxic action of CrO3. The fact that MN and apoptosis were reduced in the group treated with genistein and CrO3 suggests that genistein could have inhibited the oxidative damage of Cr(VI) since, as there were no cells with damage, the apoptotic pathways were not activated.

Structural fingerprinting of pleiotropic flavonoids for multifaceted Alzheimer's disease

Alzheimer's disease has emerged as one of the most challenging neurodegenerative diseases associated with dementia, loss of cognitive functioning and memory impairment. Despite enormous efforts to identify disease modifying technologies, the repertoire of currently approved drugs consists of a few symptomatic candidates that are not capable of halting disease progression. Moreover, these single mechanism drugs target only a small part of the pathological cascade and do not address most of the etiological basis of the disease. Development of therapies that are able to simultaneously tackle all the multiple interlinked causative factors such as amyloid protein aggregation, tau hyperphosphorylation, cholinergic deficit, oxidative stress, metal dyshomeostasis and neuro-inflammation has become the focus of intensive research in this domain. Flavonoids are natural phytochemicals that have demonstrated immense potential as medicinal agents due to their multiple beneficial therapeutic effects. The polypharmacological profile of flavonoids aligns well with the multifactorial pathological landscape of Alzheimer's disease, making them promising candidates to overcome the challenges of this neurodegenerative disorder. This review presents a detailed overview of the pleiotropic biology of flavonoids favourable for Alzheimer therapeutics and the structural basis for these effects. Structure activity trends for several flavonoid classes such as flavones, flavonols, flavanones, isoflavones, flavanols and anthocyanins are comprehensively analyzed in detail and presented.

Non-Enzymatic Antioxidants against Alzheimer's Disease: Prevention, Diagnosis and Therapy

Alzheimer's disease (AD) is a neurodegenerative disorder characterized by progressive memory loss and cognitive decline. Although substantial research has been conducted to elucidate the complex pathophysiology of AD, the therapeutic approach still has limited efficacy in clinical practice. Oxidative stress (OS) has been established as an early driver of several age-related diseases, including neurodegeneration. In AD, increased levels of reactive oxygen species mediate neuronal lipid, protein, and nucleic acid peroxidation, mitochondrial dysfunction, synaptic damage, and inflammation. Thus, the identification of novel antioxidant molecules capable of detecting, preventing, and counteracting AD onset and progression is of the utmost importance. However, although several studies have been published, comprehensive and up-to-date overviews of the principal anti-AD agents harboring antioxidant properties remain scarce. In this narrative review, we summarize the role of vitamins, minerals, flavonoids, non-flavonoids, mitochondria-targeting molecules, organosulfur compounds, and carotenoids as non-enzymatic antioxidants with AD diagnostic, preventative, and therapeutic potential, thereby offering insights into the relationship between OS and neurodegeneration.

Phytochemical Compounds and Nanoparticles as Phytochemical Delivery Systems for Alzheimer's Disease Management

Alzheimer's disease remains one of the most widespread neurodegenerative reasons for dementia worldwide and is associated with considerable mortality and morbidity. Therefore, it has been considered a priority for research. Indeed, several risk factors are involved in the complexity of the therapeutic ways of this pathology, including age, traumatic brain injury, genetics, exposure to aluminum, infections, diabetes, vascular diseases, hypertension, dyslipidemia, and obesity. The pathophysiology of Alzheimer's disease is mostly associated with hyperphosphorylated protein in the neuronal cytoplasm and extracellular plaques of the insoluble β-amyloid peptide. Therefore, the management of this pathology needs the screening of drugs targeting different pathological levels, such as acetylcholinesterase (AchE), amyloid β formation, and lipoxygenase inhibitors. Among the pharmacological strategies used for the management of Alzheimer's disease, natural drugs are considered a promising therapeutic strategy. Indeed, bioactive compounds isolated from different natural sources exhibit important anti-Alzheimer effects by their effectiveness in promoting neuroplasticity and protecting against neurodegeneration as well as neuroinflammation and oxidative stress in the brain. These effects involve different sub-cellular, cellular, and/or molecular mechanisms, such as the inhibition of acetylcholinesterase (AchE), the modulation of signaling pathways, and the inhibition of oxidative stress. Moreover, some nanoparticles were recently used as phytochemical delivery systems to improve the effects of phytochemical compounds against Alzheimer's disease. Therefore, the present work aims to provide a comprehensive overview of the key advances concerning nano-drug delivery applications of phytochemicals for Alzheimer's disease management.

Multi-Target Mechanisms of Phytochemicals in Alzheimer’s Disease: Effects on Oxidative Stress, Neuroinflammation and Protein Aggregation

Alzheimer’s disease (AD) is a neurodegenerative disease characterized by a tangle-shaped accumulation of beta-amyloid peptide fragments and Tau protein in brain neurons. The pathophysiological mechanism involves the presence of Aβ-amyloid peptide, Tau protein, oxidative stress, and an exacerbated neuro-inflammatory response. This review aims to offer an updated compendium of the most recent and promising advances in AD treatment through the administration of phytochemicals. The literature survey was carried out by electronic search in the following specialized databases PubMed/Medline, Embase, TRIP database, Google Scholar, Wiley, and Web of Science regarding published works that included molecular mechanisms and signaling pathways targeted by phytochemicals in various experimental models of Alzheimer’s disease in vitro and in vivo. The results of the studies showed that the use of phytochemicals against AD has gained relevance due to their antioxidant, anti-neuroinflammatory, anti-amyloid, and anti-hyperphosphorylation properties of Tau protein. Some bioactive compounds from plants have been shown to have the ability to prevent and stop the progression of Alzheimer’s.

Protective Effects of Flavonoids against Alzheimer's Disease: Pathological Hypothesis, Potential Targets, and Structure-Activity Relationship

Alzheimer’s disease (AD) is a neurodegenerative disease with high morbidity and mortality, for which there is no available cure. Currently, it is generally believed that AD is a disease caused by multiple factors, such as amyloid-beta accumulation, tau protein hyperphosphorylation, oxidative stress, and inflammation. Multitarget prevention and treatment strategies for AD are recommended. Interestingly, naturally occurring dietary flavonoids, a class of polyphenols, have been reported to have multiple biological activities and anti-AD effects in several AD models owing to their antioxidative, anti-inflammatory, and anti-amyloidogenic properties. In this review, we summarize and discuss the existing multiple pathogenic factors of AD. Moreover, we further elaborate on the biological activities of natural flavonoids and their potential mode of action and targets in managing AD by presenting a wide range of experimental evidence. The gathered data indicate that flavonoids can be regarded as prophylactics to slow the advancement of AD or avert its onset. Different flavonoids have different activities and varying levels of activity. Further, this review summarizes the structure–activity relationship of flavonoids based on the existing literature and can provide guidance on the design and selection of flavonoids as anti-AD drugs.

Design and synthesis of benzyl aminocoumarin and its anti-Alzheimer's activity

Benzylaminocoumarin is a kind of compound with coumarin skeleton and benzylamino side chain structure at positions 3 and 4.

Acetylcholinesterase inhibitory activity, anti-inflammatory, and neuroprotective potential of Hippeastrum psittacinum (Ker Gawl.) herb (Amaryllidaceae)

Hippeastrum psittacinum, Amaryllidaceae, is used in traditional medicine as a purgative, aphrodisiac, and anticough remedy. The ethanol extract (EE) and alkaloid-rich fractions (ARF) from H. psittacinum bulbs were evaluated for their acetylcholinesterase (AChE) inhibition. The EE cytotoxic and anti-inflammatory effects in RAW 264.7 cells, and the neuroprotective and genotoxic activities in SH-SY5Y cells, were also estimated. Fifteen alkaloids were identified in the EE by gas chromatography-mass spectrometry. ARFs were less active for AChE inhibition than EE. The viability of both cell lines was higher than 70% with EE concentrations below 25 μg/mL. The EE decreased nitrite release in RAW cells stimulated with lipopolysaccharide, showing values of 83, 67, and 53% at 6.25, 12.5, and 25 μg/mL, respectively. Furthermore, the EE partially protected SH-SY5Y cells from hydrogen peroxide-mediated deleterious effects by approximately 50% at the same concentrations. The micronucleus assays showed that the extract caused chromosomal missegregation at concentrations above 12.5 μg/mL. The in silico analyses showed that some alkaloids presented properties of permeation of the blood-brain barrier and the intestine. Our findings present new evidence of the potential of H. psittacinum potential as an AChE inhibitor, as well as an anti-inflammatory and neuroprotective agent.