Gallic acid: A naturally occurring bifunctional inhibitor of amyloid and metal induced aggregation with possible implication in metal-based therapy

Biophysical insight into anti-amyloidogenic nature of novel ionic Co(II)(phen)(H2O)4]+[glycinate]- chemotherapeutic drug candidate against human lysozyme aggregation

In the recent past, there has been an ever-increasing interest in the search for metal-based therapeutic drug candidates for protein misfolding disorders (PMDs) particularly neurodegenerative disorders such as Alzheimer's, Parkinson's, Prion's diseases, and amyotrophic lateral sclerosis. Also, different amyloidogenic variants of human lysozyme (HL) are involved in hereditary systemic amyloidosis. Metallo-therapeutic agents are extensively studied as antitumor agents, however, they are relatively unexplored for the treatment of non-neuropathic amyloidoses. In this work, inhibition potential of a novel ionic cobalt(II) therapeutic agent (CoTA) of the formulation [Co(phen)(H2O)4]+[glycinate]- is evaluated against HL fibrillation. Various biophysical techniques viz., dye-binding assays, dynamic light scattering (DLS), differential scanning calorimetry (DSC), electron microscopy, and molecular docking experiments validate the proposed mechanism of inhibition of HL fibrillation by CoTA. The experimental corroborative results of these studies reveal that CoTA can suppress and slow down HL fibrillation at physiological temperature and pH. DLS and 1-anilino-8-naphthalenesulfonate (ANS) assay show that reduced fibrillation in the presence of CoTA is marked by a significant decrease in the size and hydrophobicity of the aggregates. Fluorescence quenching and molecular docking results demonstrate that CoTA binds moderately to the aggregation-prone region of HL (Kb = 6.6 × 104 M-1), thereby, inhibiting HL fibrillation. In addition, far-UV CD and DSC show that binding of CoTA to HL does not cause any change in the stability of HL. More importantly, CoTA attenuates membrane damaging effects of HL aggregates against RBCs. This study identifies inorganic metal complexes as a therapeutic intervention for systemic amyloidosis.

Effect of the type of brewing water on the sensory and physicochemical properties of light-scented and strong-scented Tieguanyin oolong teas

Variations in the quality of brewing water profoundly impact tea flavor. This study systematically investigated the effects of four common water sources, including pure water (PW), mountain spring water (MSW), mineral water (MW) and natural water (NW) on the flavor of Tieguanyin tea infusion. Brewing with MW resulted in a flat taste and turbid aroma, mainly due to the low leaching of tea flavor components and complex interactions with mineral ions (mainly Ca2+, Mg2+). Tea infusions brewed with NW exhibited the highest relative contents of total volatile compounds, while those brewed with PW had the lowest. NW and MSW, with moderate mineralization, were conducive to improving the aroma quality of tea infusion and were more suitable for brewing both aroma types of Tieguanyin. These findings offer valuable insights into the effect of brewing water on the sensory and physicochemical properties of oolong teas.

Understanding the Modulation of α-Synuclein Fibrillation by N-Acetyl Aspartate: A Brain Metabolite

α-Synuclein (α-Syn) fibrillation is a prominent contributor to neuronal deterioration and plays a significant role in the advancement of Parkinson's Disease (PD). Considering this, the exploration of novel compounds that can inhibit or modulate the aggregation of α-Syn is a topic of significant research. This study, for the first time, elucidated the effect of N-acetyl aspartate (NAA), a brain osmolyte, on α-Syn aggregation using spectroscopic and microscopic approaches. Thioflavin T (ThT) assay revealed that a lower concentration of NAA inhibits α-Syn aggregation, whereas higher concentrations of NAA accelerate the aggregation. Further, this paradoxical effect of NAA was complemented by ANS, RLS, and the turbidity assay. The secondary structure transition was more pronounced at higher concentrations of NAA by circular dichroism, corroborating the fluorescence spectroscopic observations. Confocal microscopy also confirmed the paradoxical effect of NAA on α-Syn aggregation. Interaction studies including fluorescence quenching and molecular docking were employed to determine the binding affinity and critical residues involved in the α-Syn-NAA interaction. The explanation for this paradoxical nature of NAA could be a solvophobic effect. The results offer a profound understanding of the modulatory mechanism of α-Syn aggregation by NAA, thereby suggesting the potential role of NAA at lower concentrations in therapeutics against α-Syn aggregation-related disorders.

Update on new trends and progress of natural active ingredients in the intervention of Alzheimer's disease, based on understanding of traditional Chinese and Western relevant theories: A review

Alzheimer's disease (AD) is one of the major neurological disorders causing death in the elderly worldwide. As a neurodegenerative disease that is difficult to prevent and cure, the pathogenesis of AD is complex and there is no effective cure. A variety of natural products derived from plants have been reported to have promising anti-AD activities, including flavonoids, terpenes, phenolic acids and alkaloids, which can effectively relieve the symptoms of AD in a variety of ways. This paper mainly reviews the pharmacological activity and mechanisms of natural products against AD. Although the clinical efficacy of these plants still needs to be determined by further high-quality studies, it may also provide a basis for future researchers to study anti-AD in depth.

Inhibitory potential of N-acetylaspartate against protein glycation, AGEs formation and aggregation: Implication of brain osmolyte in glycation-related complications

Protein glycation and aggregation have a pivotal role in many diseases including diabetes and neurodegenerative disorders. N-acetyl aspartate (NAA), an osmolyte derived from L-aspartic acid, is one of the most abundant metabolites in the mammalian brain. Although NAA is supposed to be a substitute for a neuronal marker, its function is not fully elucidated. Herein, we have investigated the effect of NAA on glycation, AGEs formation and aggregation of irisin. AGE-specific fluorescence showed the strong inhibition of AGEs formation in the presence of NAA, demonstrating its anti-glycating property. The aggregates present in MG-modified irisin were also reduced by NAA, which was confirmed by Thioflavin T fluorescence and fluorescence microscopy. Further, for the explanation of the strong anti-glycating potential of NAA, the interaction between irisin and NAA was also examined. Interaction studies involving steady-state fluorescence and molecular docking demonstrated that hydrogen bonding and salt bridges by NAA stabilize the irisin. It was found that glycation-prone residues i.e., lysine and arginine are specifically involved in the interaction which might prevent them from getting modified during the process of glycation. This study for the first time reported the antiglycating potential of NAA which can be implicated in the therapeutic management of various glycation-related complications.

Mechanistic and biophysical insight into the inhibitory and disaggregase role of antibiotic moxifloxacin on human lysozyme amyloid formation

Lysozyme amyloidosis is a systemic non-neuropathic disease caused by the accumulation of amyloids of mutant lysozyme. Presently, therapeutic interventions targeting lysozyme amyloidosis, remain elusive with only therapy available for lysozyme amyloidosis being supportive management. In this work, we examined the effects of moxifloxacin, a synthetic fluoroquinolone antibiotic on the amyloid formation of human lysozyme. The ability of moxifloxacin to interfere with lysozyme amyloid aggregation was examined using various biophysical methods like Rayleigh light scattering, Thioflavin T fluorescence assay, transmission electron microscopy and docking method. The reduction in scattering and ThT fluorescence along with extended lag phase in presence of moxifloxacin, suggest that the antibiotic inhibits and impedes the lysozyme fibrillation in concentration dependent manner. From ANS experiment, we deduce that moxifloxacin is able to decrease the hydrophobicity of the protein molecule thereby preventing aggregation. Our CD and DLS results show that moxifloxacin stabilizes the protein in its native monomeric structure, thus also showing retention of lytic activity upto 69% and inhibition of cytotoxicity at highest concentration of moxifloxacin. The molecular docking showed that moxifloxacin forms a stable complex of -7.6 kcal/mol binding energy and binds to the aggregation prone region of lysozyme thereby stabilising it and preventing aggregation. Moxifloxacin also showed disaggregase potential by disrupting fibrils and decreasing the β-sheet content of the fibrils. Our current study, thus highlight the anti-amyloid and disaggregase property of an antibiotic moxifloxacin and hence sheds light on the future of antibiotics against protein aggregation, a hallmark event in many neurodegenerative diseases.

Photooxidative inhibition and decomposition of β-amyloid in Alzheimer's by nano-assemblies of transferrin and indocyanine green

Photoinduced modulation of Aβ₄₂ aggregation has emerged as a therapeutic option for treating Alzheimer's disease (AD) due to its high spatiotemporal controllability, noninvasive nature, and low systemic toxicity. However, existing photo-oxidants have the poor affinity for Aβ₄₂, low depolymerization efficiency, and difficulty in crossing the blood-brain barrier (BBB), hindering their application in the treatment of AD. Here, through hydrophobic interactions and hydrogen bonding, we integrated the near-infrared (NIR) photosensitizer indocyanine green with transferrin (denoted as TF-ICG), a protein with a high affinity for Aβ₄₂, and demonstrated its anti-amyloid activity in vitro. TF-ICG was shown to bind to Aβ₄₂ residues via hydrophobic interaction, impeding π-π stacking of Aβ₄₂ peptide monomers and disassembling mature Aβ₄₂ protofibrils in a concentration-dependent manner. More importantly, under NIR (808 nm, 0.6w/cm²) irradiation, TF-ICG completely inhibited the fibrillation process of Aβ₄₂ to generate amorphous aggregates, with an inhibition rate of 96 % at only 65 nM. Meanwhile, TF-ICG could photo-oxidize rigid Aβ₄₂ aggregates and break them down into small amorphous structures. Tyrosine fluorescence assay further demonstrated the intrinsic affinity and targeting of TF-ICG to Aβ₄₂ fibrils. In vitro studies validated the anti-amyloid activity of TF-ICG, which provided a theoretical basis for further in vivo application as a BBB-penetrating nanotherapeutic platform.

Comprehensive insights into the gallic acid assisted bioleaching process for spent LIBs: Relationships among bacterial functional genes, Co(III) reduction and metal dissolution behavior

Despite the growing demand for resource recovery from spent lithium-ion batteries (LIBs) by bioleaching, low Co leaching efficiency has hindered the development and application of this technology. Therefore, a novel process was designed, combining gallic acid (GA) and mixed culture bioleaching (MCB), to enhance the removal of metals from spent LIBs. Results indicated that the GA + MCB process achieved 98.03% Co and 98.02% Li leaching from spent LIBs, simultaneously reducing the biotoxicity, phytotoxicity and leaching toxicity of spent LIBs under optimal conditions. The results of mechanism analysis demonstrated that functional microorganisms adapted to the leaching system through various strategies, including oxidative stress reduction, DNA damage repair, heavy metal resistance and biofilm formation, maintaining normal physiological activities and the continuous production of biological acid. The biological acid erodes the surface of waste LIBs, causing some Co and a large amount of Li to be released, while also increasing the contact area between GA and Co(III). Therefore, GA is beneficial for reducing insoluble Co(III), forming soluble Co(II). Finally, biological acid can effectively promote Co(II) leaching. Collectively, the results of this study provide valuable insight into the simultaneous enhancement of metal extraction and the mitigation of environmental pollution from spent LIBs.

The effect of novel antihypertensive drug valsartan on lysozyme aggregation: A combined in situ and in silico study

Protein misfolding can result in amyloid fiber aggregation, which is associated with various types of diseases. Therefore, preventing or treating abnormally folded proteins may provide therapeutic intervention for these diseases. Valsartan (VAL) is an angiotensin II receptor blocker (ARB) that is used to treat hypertension. In this study, we examine the anti-aggregating effect of VAL against hen egg-white lysozyme (HEWL) amyloid fibrils through spectroscopy, docking, and microscopic analysis. In vitro formation of HEWL amyloid fibrils was indicated by increased turbidity, RLS (Rayleigh light scattering), and ThT fluorescence intensity. 10 μM VAL, amyloid/aggregation was inhibited up to 83% and 72% as measured by ThT and RLS respectively. In contrast, 100 μM VAL significantly increases the fibril aggregation of HEWL. CD spectroscopy results show a stabilization of HEWL α-helical structures in the presence of 10 μM VAL while the increase in β-sheet was detected at 100 μM concentration of VAL. The hydrophobicity of HEWL was increased at 100 μM VAL, suggesting the promotion of aggregation via its self-association. Steady-state quenching revealed that VAL and HEWL interact spontaneously via hydrogen bonds and van der Waals forces. Transmission electron microscopy (TEM) images illustrate that the needle-like fibers of HEWL amyloid were reduced at 10 μM VAL, while at 100 μM the fibrils of amyloid were increased. Additionally, our computational studies showed that VAL could bind to two binding sites within HEWL. In the BS-1 domain of HEWL, VAL binds to ASN⁵⁹, ILE⁹⁸, ILE⁵⁸, TRP¹⁰⁸, VAL¹⁰⁹, SER⁵⁰, ASP⁵², ASN⁵⁹, ALA¹⁰⁷, and TRP¹⁰⁸ residues with a binding energy of -9.72 kcal mol^-1. Also, it binds to GLU⁷, ALA¹⁰, ALA¹¹, CYS⁶, ARG¹²⁸, and ARG¹⁴ in the BS-2 domain with a binding energy of -5.89 kcal mol^-1. VAL, therefore, appears to have dual effect against HEWL aggregation. We suggest that VAL stabilizes HEWL's aggregation-prone region (APR) at 10 μM, preventing aggregation. Also, we assume that at 100 μM, VAL occupies BS-2 beside BS-1 and destabilizes the folding structure of HEWL, resulting in aggregation. Further studies are needed to investigate the mechanism of action and determine its potential side effects.

Characterization of advanced glycation end products and aggregates of irisin: Multispectroscopic and microscopic approaches

Glycation of proteins leading to the formation of advanced glycation end products (AGEs) has been demonstrated to contribute to the pathogenesis of several diseases. Irisin is a clinically significant protein, putatively involved in obesity, diabetes, and neurological disorders. This study aimed to monitor the methyl-glyoxal (MG) induced AGEs and aggregate formation of irisin, as a function of time, employing multispectroscopic and microscopic approaches. ANS fluorescence suggested a molten globule-like state on Day 6, followed by the formation of irisin AGEs adducts, as confirmed by AGE-specific fluorescence. Glycation of irisin led to aggregate formation, which was characterized by Thioflavin T fluorescence, CD spectroscopy, and microscopic studies. These aggregates were confirmed by exploiting fluorescence microscopy, confocal, and transmission electron microscopy. Molecular docking was performed to determine the crucial residues of irisin involved in irisin-MG interaction. Usually, MG is present in trace amounts as a metabolic by-product in the body, which is found to be elevated in diseased conditions viz. diabetes and Alzheimer's disease. This study characterized the AGEs and aggregates of clinically important protein, irisin; and since MG level has been found to be increased in various pathological conditions, this study provides a clinical perspective. There is a possibility that elevated MG concentrations might glycate irisin resulting in reduced irisin levels as reported in pathological conditions. However, further investigations are required to prove it.

Curcumin-loaded protein imprinted mesoporous nanosphere for inhibiting amyloid aggregation

Some natural variants of human lysozyme are associated with systemic non-neurological amyloidosis that leads to amyloid protein fibril deposition in different tissues. Inhibition of amyloid fibrillation by nanomaterials is considered to be an effective approach to treating amyloidosis. Here, we prepared a targeted, highly loaded curcumin lysozyme-imprinted nanosphere (CUR-MIMS) that could effectively inhibit the aggregation of lysozyme with lysozyme adsorption capacity of 193.57 mg g^-1 and the imprinting factor (IF) of 3.72. CUR-MIMS could bind to lysozyme through hydrophobic interactions and effectively reduce the hydrophobicity of the total solvent-exposed surface in lysozyme fibrillation, thus reducing the self-assembly process triggered by hydrophobic interactions. Thioflavin T (ThT) analysis demonstrated that CUR-MIMS inhibited the aggregation of amyloid fibrils in a dose-dependent manner (inhibition efficiency of 56.07 %). Circular dichroism (CD) spectrum further illustrated that CUR-MIMS could significantly inhibit the transition of lysozyme from α-helix structure to β-sheet. More importantly, biological experiments proved the good biocompatibility of CUR-MIMS, which indicated the potential of our system as a future therapeutic platform for amyloidosis.

The amyloid state of proteins: A boon or bane?

Proteins and their aggregation is significant field of research due to their association with various conformational maladies including well-known neurodegenerative diseases like Alzheimer's (AD), Parkinson's (PD), and Huntington's (HD) diseases. Amyloids despite being given negative role for decades are also believed to play a functional role in bacteria to humans. In this review, we discuss both facets of amyloid. We have shed light on AD, which is one of the most common age-related neurodegenerative disease caused by accumulation of Aβ fibrils as extracellular senile plagues. We also discuss PD caused by the aggregation and deposition of α-synuclein in form of Lewy bodies and neurites. Other amyloid-associated diseases such as HD and amyotrophic lateral sclerosis (ALS) are also discussed. We have also reviewed functional amyloids that have various biological roles in both prokaryotes and eukaryotes that includes formation of biofilm and cell attachment in bacteria to hormone storage in humans, We discuss in detail the role of Curli fibrils' in biofilm formation, chaplins in cell attachment to peptide hormones, and Pre-Melansomal Protein (PMEL) roles. The disease-related and functional amyloids are compared with regard to their structural integrity, variation in regulation, and speed of forming aggregates and elucidate how amyloids have turned from foe to friend.

The Use of Bioactive Compounds in Hyperglycemia- and Amyloid Fibrils-Induced Toxicity in Type 2 Diabetes and Alzheimer’s Disease

It has become increasingly apparent that defective insulin signaling may increase the risk for developing Alzheimer’s disease (AD), influence neurodegeneration through promotion of amyloid formation or by increasing inflammatory responses to intraneuronal β-amyloid. Recent work has demonstrated that hyperglycemia is linked to cognitive decline, with elevated levels of glucose causing oxidative stress in vulnerable tissues such as the brain. The ability of β-amyloid peptide to form β-sheet-rich aggregates and induce apoptosis has made amyloid fibrils a leading target for the development of novel pharmacotherapies used in managing and treatment of neuropathological conditions such as AD-related cognitive decline. Additionally, deposits of β-sheets folded amylin, a glucose homeostasis regulator, are also present in diabetic patients. Thus, therapeutic compounds capable of reducing intracellular protein aggregation in models of neurodegenerative disorders may prove useful in ameliorating type 2 diabetes mellitus symptoms. Furthermore, both diabetes and neurodegenerative conditions, such as AD, are characterized by chronic inflammatory responses accompanied by the presence of dysregulated inflammatory biomarkers. This review presents current evidence describing the role of various small bioactive molecules known to ameliorate amyloidosis and subsequent effects in prevention and development of diabetes and AD. It also highlights the potential efficacy of peptide–drug conjugates capable of targeting intracellular targets.

Novel strategies for the fight of Alzheimer's disease targeting amyloid-β protein

Alzheimer's disease (AD), which is recognised as a devastating neurodegenerative disease throughout the world and lack of effective treatments, is a growing concern in modern society with a growing population of elderly patients. A growing number of studies reveal that abnormal accumulation and deposition of Aβ is responsible for AD. Inspired by this, strategies for the treatment of AD targeting-Aβ clearance have been discussed for a long period, exploring new drugs which is capable of destroying soluble Aβ oligomers and unsolvable Aβ aggregates. In this paper, results of recent clinical trials on several anti-amyloid-β drugs are presented and several emerging anti-amyloid AD therapies based on recent studies are reviewed. Furthermore, some of the current challenges and novel strategies to prevent AD are addressed. Herein, this review focuses on current pharmacotherapy of AD targeting-Aβ and intends to design a promising therapeutic agent for AD treatment.

Proteostasis of Islet Amyloid Polypeptide: A Molecular Perspective of Risk Factors and Protective Strategies for Type II Diabetes

The possible link between hIAPP accumulation and β-cell death in diabetic patients has inspired numerous studies focusing on amyloid structures and aggregation pathways of this hormone. Recent studies have reported on the importance of early oligomeric intermediates, the many roles of their interactions with lipid membrane, pH, insulin, and zinc on the mechanism of aggregation of hIAPP. The challenges posed by the transient nature of amyloid oligomers, their structural heterogeneity, and the complex nature of their interaction with lipid membranes have resulted in the development of a wide range of biophysical and chemical approaches to characterize the aggregation process. While the cellular processes and factors activating hIAPP-mediated cytotoxicity are still not clear, it has recently been suggested that its impaired turnover and cellular processing by proteasome and autophagy may contribute significantly toward toxic hIAPP accumulation and, eventually, β-cell death. Therefore, studies focusing on the restoration of hIAPP proteostasis may represent a promising arena for the design of effective therapies. In this review we discuss the current knowledge of the structures and pathology associated with hIAPP self-assembly and point out the opportunities for therapy that a detailed biochemical, biophysical, and cellular understanding of its aggregation may unveil.

Polyphenols as Potential Metal Chelation Compounds Against Alzheimer's Disease

Alzheimer's disease (AD) is the most common neurodegenerative disease affecting more than 50 million people worldwide. The pathology of this multifactorial disease is primarily characterized by the formation of amyloid-β (Aβ) aggregates; however, other etiological factors including metal dyshomeostasis, specifically copper (Cu), zinc (Zn), and iron (Fe), play critical role in disease progression. Because these transition metal ions are important for cellular function, their imbalance can cause oxidative stress that leads to cellular death and eventual cognitive decay. Importantly, these transition metal ions can interact with the amyloid-β protein precursor (AβPP) and Aβ42 peptide, affecting Aβ aggregation and increasing its neurotoxicity. Considering how metal dyshomeostasis may substantially contribute to AD, this review discusses polyphenols and the underlying chemical principles that may enable them to act as natural chelators. Furthermore, polyphenols have various therapeutic effects, including antioxidant activity, metal chelation, mitochondrial function, and anti-amyloidogenic activity. These combined therapeutic effects of polyphenols make them strong candidates for a moderate chelation-based therapy for AD.

Amide derivatives of Gallic acid: Design, synthesis and evaluation of inhibitory activities against in vitro α-synuclein aggregation

Gallic acid (GA), a natural phenolic acid, has received numerous attention because of its anti-oxidative, anti-inflammatory, and anti-cancer activity. More importantly, GA can act as an efficient inhibitor of α-Synuclein (α-Syn) aggregation at early stages. Nevertheless, some evidences suggest that GA is unlikely to cross the blood-brain barrier because of its high hydrophilicity. Hence, GA may not be considered as a promising candidate or entering brain and directly affecting the central nervous system. Accordingly, we have designed and synthesized a series of amide derivatives of GA, some of which possess appropriate lipophilicity and hydrophilicity with LogP (2.09-2.79). Meanwhile, these sheet-like conjugated compounds have good π-electron delocalization and high ability of hydrogen-bond formation. Some compounds have shown better in vitro anti-aggregation activities than GA towards α-Syn, with IC₅₀ down to 0.98 μM. The valid modification strategy of GA is considered an efficient way to discover novel inhibitors of α-Syn aggregation.

Probing the Nongeneralized Amyloid Inhibitory Mechanism of Hydrophobic Chaperone

Increasing prevalence of protein misfolding disorders urges the search for effective therapies. Although several antiaggregation molecules have been identified, their molecular process of aggregation and clinical trials are underway. The present study is focused on the mechanism through which phenyl butyrate (PB), a chemical chaperone, triggers inhibition of human serum albumin (HSA) fibrillation. Turbidity and Rayleigh light scattering (RLS) measurements reveal the marked presence of aggregates in HSA that were confirmed as amyloid fibrils by thioflavin T (ThT) and Congo red (CR) and were subsequently inhibited by PB in a dose dependent manner. ThT fluorescence kinetics reveals a decrease in the apparent rate constant, K_app, in the presence of PB without triggering a lag phase in HSA suggesting PB's interference with the elongation phase. Dynamic light scattering (DLS) results display a reduction in the aggregate size in the presence of PB. Isothermal titration calorimetry (ITC) data reveals strong binding of PB at site II both at 25 °C (K_b ≈ 1.94 × 10⁵ M^-1) and 65 °C (K_b ≈ 2.90 × 10⁴ M^-1), mediated by hydrogen bonding. Overall, our finding establishes that PB stabilizes partially unfolded HSA molecules through hydrogen bonding, thereby preventing establishment of hydrogen bonds between them and hindering their progression into amyloid fibrils. This is in contrast to its chaperone effect manifested with other proteins.

Anthocyanins and Their Metabolites as Therapeutic Agents for Neurodegenerative Disease

Neurodegenerative diseases, including Alzheimer’s disease, Parkinson’s disease, and amyotrophic lateral sclerosis (ALS), are characterized by the death of neurons within specific regions of the brain or spinal cord. While the etiology of many neurodegenerative diseases remains elusive, several factors are thought to contribute to the neurodegenerative process, such as oxidative and nitrosative stress, excitotoxicity, endoplasmic reticulum stress, protein aggregation, and neuroinflammation. These processes culminate in the death of vulnerable neuronal populations, which manifests symptomatically as cognitive and/or motor impairments. Until recently, most treatments for these disorders have targeted single aspects of disease pathology; however, this strategy has proved largely ineffective, and focus has now turned towards therapeutics which target multiple aspects underlying neurodegeneration. Anthocyanins are unique flavonoid compounds that have been shown to modulate several of the factors contributing to neuronal death, and interest in their use as therapeutics for neurodegeneration has grown in recent years. Additionally, due to observations that the bioavailability of anthocyanins is low relative to that of their metabolites, it has been proposed that anthocyanin metabolites may play a significant part in mediating the beneficial effects of an anthocyanin-rich diet. Thus, in this review, we will explore the evidence evaluating the neuroprotective and therapeutic potential of anthocyanins and their common metabolites for treating neurodegenerative diseases.

Protein misfolding, aggregation and mechanism of amyloid cytotoxicity: An overview and therapeutic strategies to inhibit aggregation

Protein and peptides are converted from their soluble forms into highly ordered fibrillar aggregates under various conditions inside the cell. Such transitions confer diverse neurodegenerative diseases including Alzheimer's disease, Huntington's disease Prion's disease, Parkinson's disease, polyQ and share abnormal folding of potentially cytotoxic protein species linked with degeneration and death of precise neuronal populations. Presently, major advances are made to understand and get detailed insight into the structural basis and mechanism of amyloid formation, cytotoxicity and therapeutic approaches to combat them. Here we highlight classifies and summarizes the detailed overview of protein misfolding and aggregation at their molecular level including the factors that promote protein aggregation under in vivo and in vitro conditions. In addition, we describe the recent technologies that aid the characterization of amyloid aggregates along with several models that might be responsible for amyloid induced cytotoxicity to cells. Overview on the inhibition of amyloidosis by targeting different small molecules (both natural and synthetic origin) have been also discussed, that provides important approaches to identify novel targets and develop specific therapeutic strategies to combat protein aggregation related neurodegenerative diseases.