Possible relation of atypical parkinsonism in the French West Indies with consumption of tropical plants: a case-control study. Caribbean Parkinsonism Study Group

Genetic forms of tauopathies: inherited causes and implications of Alzheimer's disease-like TAU pathology in primary and secondary tauopathies

Tauopathies are a heterogeneous group of neurologic diseases characterized by pathological axodendritic distribution, ectopic expression, and/or phosphorylation and aggregation of the microtubule-associated protein TAU, encoded by the gene MAPT. Neuronal dysfunction, dementia, and neurodegeneration are common features of these often detrimental diseases. A neurodegenerative disease is considered a primary tauopathy when MAPT mutations/haplotypes are its primary cause and/or TAU is the main pathological feature. In case TAU pathology is observed but superimposed by another pathological hallmark, the condition is classified as a secondary tauopathy. In some tauopathies (e.g. MAPT-associated frontotemporal dementia (FTD), progressive supranuclear palsy (PSP), corticobasal degeneration (CBD), and Alzheimer's disease (AD)) TAU is recognized as a significant pathogenic driver of the disease. In many secondary tauopathies, including Parkinson's disease (PD) and Huntington's disease (HD), TAU is suggested to contribute to the development of dementia, but in others (e.g. Niemann-Pick disease (NPC)) TAU may only be a bystander. The genetic and pathological mechanisms underlying TAU pathology are often not fully understood. In this review, the genetic predispositions and variants associated with both primary and secondary tauopathies are examined in detail, assessing evidence for the role of TAU in these conditions. We highlight less common genetic forms of tauopathies to increase awareness for these disorders and the involvement of TAU in their pathology. This approach not only contributes to a deeper understanding of these conditions but may also lay the groundwork for potential TAU-based therapeutic interventions for various tauopathies.

Traditional medical practices for children in five islands from the Society archipelago (French Polynesia)

BACKGROUND

Traditional Polynesian medicine for children has been poorly documented, and few data are available on their efficacy and safety. In this context, the aim of this study was to identify traditional practices used for treating children and then assess the efficacy and safety of the most cited remedies by reviewing the literature.

METHODS

In 2022, a semi-structured survey was carried out on five islands from the Society archipelago (Bora Bora, Huahine, Moorea, Raiatea, and Tahiti). A total of 86 participants were interviewed including 19 experts in herbalism. A thorough literature review was performed on the most cited plant species to gather the relevant ethnobotanical, pharmacological, and clinical data of each remedy.

RESULTS

Participants mentioned using 469 remedies to treat 69 health disorders. The most represented health categories were digestive system, skin disorders, infectious diseases, and respiratory system. A total of 67 plant species (representing 731 use-reports) were mentioned and Annona muricata, Gardenia taitensis, and Hibiscus rosa-sinensis were the main plants reported. Regarding the safety of cited remedies, one plant (Microsorum grossum) showed high risk of toxicity, and its use should be avoided in infants and children.

CONCLUSION

Our survey confirms the importance of traditional medical practices for children in the Society Islands. A lack of data in children for most cited remedies demonstrate the need for more pharmacological and toxicological research on Polynesian medicinal plants. Finally, the potential risk of toxicity for some cited plant species reported calls for a better information of traditional medicine users and healers.

Endemic parkinsonism: clusters, biology and clinical features

The term 'endemic parkinsonism' refers to diseases that manifest with a dominant parkinsonian syndrome, which can be typical or atypical, and are present only in a particular geographically defined location or population. Ten phenotypes of endemic parkinsonism are currently known: three in the Western Pacific region; two in the Asian-Oceanic region; one in the Caribbean islands of Guadeloupe and Martinique; and four in Europe. Some of these disease entities seem to be disappearing over time and therefore are probably triggered by unique environmental factors. By contrast, other types persist because they are exclusively genetically determined. Given the geographical clustering and potential overlap in biological and clinical features of these exceptionally interesting diseases, this Review provides a historical reference text and offers current perspectives on each of the 10 phenotypes of endemic parkinsonism. Knowledge obtained from the study of these disease entities supports the hypothesis that both genetic and environmental factors contribute to the development of neurodegenerative diseases, not only in endemic parkinsonism but also in general. At the same time, this understanding suggests useful directions for further research in this area.

Natural Acetogenins, Chatenaytrienins-1, -2, -3 and -4, Mitochondrial Potential Uncouplers and Autophagy Inducers-Promising Anticancer Agents

The present paper details the complete stereoselective synthesis of four natural acetogenins, chatenaytrienins-1, -2, -3 and -4, previously isolated from the roots of fruit trees of the family Annonaceae (A. nutans and A. muricata), as an inseparable mixture. The novel organometallic reactions, developed by the authors, of Ti-catalyzed cross-cyclomagnesiation of O-containing and aliphatic allenes using available Grignard reagents were applied at the key stage of synthesis. We have studied the biological activity of the synthesized individual chatenaytrienins-1, -2, -3 and -4 in vitro, including their cytotoxicity in a panel of tumor lines and their ability to induce apoptosis, affect the cell cycle and mitochondria, and activate the main apoptotic signaling pathways in the cell, applying modern approaches of flow cytometry and multiplex analysis with Luminex xMAP technology. It has been shown that chatenaytrienins affect mitochondria by uncoupling the processes of mitochondrial respiration, causing the accumulation of ROS ions, followed by the initiation of apoptosis. The most likely mechanism for the death of cortical neurons from the consumption of tea from the seeds of Annona fruit is long-term chronic hypoxia, which leads to the development of an atypical form of Parkinson's disease that is characteristic of the indigenous inhabitants of Guam and New Caledonia.

Differences Among Native Hawaiian, Asian, and White Patients with Progressive Supranuclear Palsy

BACKGROUND

Most studies of progressive supranuclear palsy (PSP) have been conducted in White populations.

OBJECTIVE

The objective of this study was to identify whether differences exist for patients with PSP among Whites, East Asians (EAs), and Native Hawaiians/Pacific Islanders (NHPIs) in Hawaii.

METHODS

We conducted a single-center, retrospective study of patients meeting Movement Disorder Society probable PSP criteria (2006-2021). Data variables included age of onset and diagnosis, comorbidities, and survival rate. Variables were compared across groups using Fisher's exact test, Kruskal-Wallis rank sum test, and log-rank tests.

RESULTS

A total of 94 (59 EAs, 9 NHPIs, 16 Whites, and 10 Others) patients were identified. Mean age ± standard deviation (in years) of symptom onset/diagnosis were both youngest in NHPIs (64.0 ± 7.2/66.3 ± 8.0) followed by Whites (70.8 ± 7.6/73.9 ± 7.8), then EAs (75.9 ± 8.2/79.2 ± 8.3) (P < 0.001). Median survival from diagnosis was significantly lower (P < 0.05) in NHPIs (2 years) compared with EAs (4 years) and Whites (6 years).

CONCLUSIONS

There may be racial disparities for PSP, and studies are needed to identify genetic, environmental, and socioeconomic contributions. © 2023 International Parkinson and Movement Disorder Society.

Brain dysfunction in gait disorders of Caribbean atypical Parkinsonism and progressive supranuclear palsy patients: A comparative study

INTRODUCTION

Gait disorders and falls occur early in progressive supranuclear palsy (PSP-RS) and Caribbean atypical parkinsonism (Caribbean AP). However, the link between these signs and brain lesions has never been explored in these patient populations. Here, we investigate and compare the imaging factors that relate to gait and balance disorders in Caribbean AP and PSP-RS patients.

METHODS

We assessed gait and balance using clinical scales and gait recordings in 16 Caribbean AP and 15 PSP-RS patients and 17 age-matched controls. We measured the grey and white matter brain volumes on 3 T brain MRI images. We performed a principal component analysis (PCA) including all the data to determine differences and similarities between groups, and explore the relationship between gait disorders and brain volumes.

RESULTS

Both Caribbean AP patients and PSP-RS have marked gait and balance disorders with similar severity. In both groups, gait and balance disorders were found to be most strongly related to structural changes in the lateral cerebellum, caudate nucleus, and fronto-parietal areas. In Caribbean AP patients, gait disorders were also related to additional changes in the cortex, including frontal, insular, temporal and cuneus lobes, whereas in PSP-RS patients, additional white matter changes involved the mesencephalon and parahippocampal gyrus.

CONCLUSION

Gait and balance disorders in Caribbean AP patients are mainly related to dysfunction of cortical brain areas involved in visuo-sensorimotor processing and self-awareness, whereas these signs mainly result from premotor-brainstem-cerebellar network dysfunction in PSP-RS patients, brain areas involved in initiation and maintenance of locomotor pattern and postural adaptation.

The Pesticide Chlordecone Promotes Parkinsonism-like Neurodegeneration with Tau Lesions in Midbrain Cultures and C. elegans Worms

Chlordecone (CLD) is an organochlorine pesticide (OCP) that is currently banned but still contaminates ecosystems in the French Caribbean. Because OCPs are known to increase the risk of Parkinson's disease (PD), we tested whether chronic low-level intoxication with CLD could reproduce certain key characteristics of Parkinsonism-like neurodegeneration. For that, we used culture systems of mouse midbrain dopamine (DA) neurons and glial cells, together with the nematode C. elegans as an in vivo model organism. We established that CLD kills cultured DA neurons in a concentration- and time-dependent manner while exerting no direct proinflammatory effects on glial cells. DA cell loss was not impacted by the degree of maturation of the culture. The use of fluorogenic probes revealed that CLD neurotoxicity was the consequence of oxidative stress-mediated insults and mitochondrial disturbances. In C. elegans worms, CLD exposure caused a progressive loss of DA neurons associated with locomotor deficits secondary to alterations in food perception. L-DOPA, a molecule used for PD treatment, corrected these deficits. Cholinergic and serotoninergic neuronal cells were also affected by CLD in C. elegans, although to a lesser extent than DA neurons. Noticeably, CLD also promoted the phosphorylation of the aggregation-prone protein tau (but not of α-synuclein) both in midbrain cell cultures and in a transgenic C. elegans strain expressing a human form of tau in neurons. In summary, our data suggest that CLD is more likely to promote atypical forms of Parkinsonism characterized by tau pathology than classical synucleinopathy-associated PD.

Computational binding affinity and molecular dynamic characterization of annonaceous acetogenins at nucleotide binding domain (NBD) of multi-drug resistance ATP-binding cassette sub-family B member 1 (ABCB1)

Multi drug resistance (MDR) in tumor might be caused leading to the overexpression of transporters, such as ATP-binding cassette sub-family B member 1 (ABCB1). A combination of non-toxic and potent ABC inhibitors along with conventional anti-cancer drugs is needed to reverse MDR in tumors. A variety of phytochemicals have been previously shown to reverse MDR. Annonaceous acetogenins (AAs) with C₃₅/C₃₇ long-chain fatty acids were reported for their anti-tumor activity, however, their effect on reversing MDR is not yet investigated. We aimed to investigate some selective AAs against the B1 subtype of ABC transporter using computational studies. Various modules of Maestro software were utilized for our in-silico analysis. Few well-characterized AAs were screened for their drug-likeness properties and tested for binding affinity at ATP and drug binding sites of ABCB1 through molecular docking. The stability of the ligand-protein complex (lowest docking score) was then determined by a molecular dynamic (MD) simulation study. Out of 24 AAs, Annonacin A (-8.10 kcal/mol) and Annohexocin (-10.49 kcal/mol) docked with a greater binding affinity at the ATP binding site than the first-generation inhibitor of ABCB1 (Verapamil: -3.86 kcal/mol). MD simulation of Annonacin A: ABCB1 complex for 100 ns also indicated that Annonacin A would stably bind to the ATP binding site. We report that Annonacin A binds at a greater affinity with ABCB1 and might act as a potential drug lead to reverse MDR in tumor cells. Communicated by Ramaswamy H. Sarma.

Identification of Annonaceous Acetogenins and Alkaloids from the Leaves, Pulp, and Seeds of Annona atemoya

Annonaceae is a large family composed of more than 119 genera and more than 2500 species that are distributed in both tropical and subtropical areas. The Annona genus is a member of Annonaceae family, which encompasses about 175 species, most of which are native to Brazil and tropical America. This plant is commonly found on tropical and subtropical continents. Annona atemoya is a commercially important hybrid of A. squamosa and A. cherimola. Phytochemical investigations of A. atemoya leaves, fruit, and seeds have been conducted in limited studies. The purpose of this study was to investigate the constituents of the leaves, fruit pulp, and seeds of A. atemoya because few studies have reported their constituents. Annonaceous acetogenins were identified in the leaves and pulp of A. atemoya for the first time. Twenty compounds were identified: sixteen were acetogenins and four were alkaloids. Additionally, two compounds were isolated, and their structures were confirmed by spectroscopic analysis and compared with the results of previous studies. The concentration of acetogenins in the pulp was very low compared with that in the leaves, whereas the seeds were found to contain the highest concentrations and greatest diversity of compounds.

Tropical spastic paraparesis

A large number of causative agents can result in spinal cord disorders in the tropics including etiologies similar to those of temperate regions such as trauma, spinal bone and disc lesions, tumors, epidural abscess, and congenital malformations. Yet infectious and nutritional disorders differ in their higher prevalence in tropical regions including Pott's disease; brucellosis; neuroborreliosis; various parasitic diseases such as schistosomiasis, neurocysticercosis, and eosinophilic meningitis. Notably, the retrovirus HTLV-1 is the causeof tropical spastic paraparesis/paraplegia or TSP. Nutritional causes of TSP include vitamin B and folate deficiencies, while endemic clusters of konzo and tropical ataxic myeloneuropathy occur in Africa, along with malnutrition and excessive consumption of cyanide-containing bitter cassava. Other toxic etiologies of TSP include lathyrism and fluorosis. Nutritional forms of myelopathy are associated often with optic and sensory neuropathy, hence the name tropical myeloneuropathies. Acute transverse myelopathy, seen in association with vaccination, infections, and fibrocartilaginous embolism of the nucleus pulposus, can be ubiquitous. Multiple sclerosis and optic myelopathy occur in the tropics but with lesser prevalence than in temperate regions. The advent of modern imaging in the tropics, including computed tomography and magnetic resonance imaging, has allowed better diagnosis and treatment of these conditions that are a frequent cause of death and disability. This chapter provides an overview of TSP emphasizing the most common causes with clues to diagnosis and effective therapy.

Annonaceae Consumption Worsens Disease Severity and Cognitive Deficits in Degenerative Parkinsonism

BACKGROUND

High consumption of Annona muricata fruit has been previously identified as a risk factor for atypical parkinsonism in the French Caribbean islands.

OBJECTIVE

We tested whether consumption of Annonaceae products could worsen the clinical phenotype of patients with any form of degenerative parkinsonism.

METHODS

We analyzed neurological data from 180 Caribbean parkinsonian patients and specifically looked for dose effects of lifelong, cumulative Annonaceae consumption on cognitive performance. Using unsupervised clustering, we identified one cluster with mild/moderate symptoms (N = 102) and one with severe symptoms including cognitive impairment (N = 78).

RESULTS

We showed that even low cumulative consumption of fruits/juices (>0.2 fruit-years) or any consumption of herbal tea from Annonaceae worsen disease severity and cognitive deficits in degenerative parkinsonism including Parkinson's disease (OR fruits-juices: 3.76 [95% CI: 1.13-15.18]; OR herbal tea: 2.91 [95% CI: 1.34-6.56]).

CONCLUSION

We suggest that more restrictive public health preventive recommendations should be made regarding the consumption of Annonaceae products. © 2022 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Mitochondrial electron transport chain defects modify Parkinson's disease phenotypes in a Drosophila model

INTRODUCTION

Mitochondrial defects have been implicated in Parkinson's disease (PD) since complex I poisons were found to cause accelerated parkinsonism in young people in the early 1980s. More evidence of mitochondrial involvement arose when many of the genes whose mutations caused inherited PD were discovered to be subcellularly localized to mitochondria or have mitochondrial functions. However, the details of how mitochondrial dysfunction might impact or cause PD remain unclear. The aim of our study was to better understand mitochondrial dysfunction in PD by evaluating mitochondrial respiratory complex mutations in a Drosophila melanogaster (fruit fly) model of PD.

METHODS

We have conducted a targeted heterozygous enhancer/suppressor screen using Drosophila mutations within mitochondrial electron transport chain (ETC) genes against a null PD mutation in parkin. The interactions were assessed by climbing assays at 2-5 days as an indicator of motor function. A strong enhancer mutation in COX5A was examined further for L-dopa rescue, oxygen consumption, mitochondrial content, and reactive oxygen species. A later timepoint of 16-20 days was also investigated for both COX5A and a suppressor mutation in cyclope. Generalized Linear Models and similar statistical tests were used to verify significance of the findings.

RESULTS

We have discovered that mutations in individual genes for subunits within the mitochondrial respiratory complexes have interactions with parkin, while others do not, irrespective of complex. One intriguing mutation in a complex IV subunit (cyclope) shows a suppressor rescue effect at early time points, improving the gross motor defects caused by the PD mutation, providing a strong candidate for drug discovery. Most mutations, however, show varying degrees of enhancement or slight suppression of the PD phenotypes. Thus, individual mitochondrial mutations within different oxidative phosphorylation complexes have different interactions with PD with regard to degree and direction. Upon further investigation of the strongest enhancer (COX5A), the mechanism by which these interactions occur initially does not appear to be based on defects in ATP production, but rather may be related to increased levels of reactive oxygen species.

CONCLUSIONS

Our work highlights some key subunits potentially involved in mechanisms underlying PD pathogenesis, implicating ETC complexes other than complex I in PD.

Dereplication of Acetogenins from Annona muricata by Combining Tandem Mass Spectrometry after Lithium and Copper Postcolumn Cationization and Molecular Networks

Annonaceous acetogenins are natural products held responsible for atypical Parkinsonism due to chronic consumption in traditional medicine or as food, leading to the development of analytical strategies for their complete chemical characterization in complex mixtures. Characterization by tandem mass spectrometry (MS/MS) of acetogenins using collision-induced dissociation from lithium adducts provides additional structural information compared to protonated or sodiated species such as ketone location on the acetogenin backbone. However, very low intensity diagnostic ions together with the lack of extensive structural information regarding position of OH and THF substituents limit this approach. Copper adducts led to diagnostic fragment ions that allow us to identify the position of oxygen rings and hydroxyl substituents. Fragmentation rules were established on the basis of acetogenin standards allowing the identification of 45 over the 77 analogues observed in an extract of Annona muricata by LC-MS/MS using postcolumn infusion of copper sulfate (CuSO₄) solution. Molecular networks that were generated thanks to specific fragmentations obtained with copper led to the distinction of THF ring position or to the identification of hydroxylated lactone, for instance.

Evolving concepts in progressive supranuclear palsy and other 4-repeat tauopathies

Tauopathies are classified according to whether tau deposits predominantly contain tau isoforms with three or four repeats of the microtubule-binding domain. Those in which four-repeat (4R) tau predominates are known as 4R-tauopathies, and include progressive supranuclear palsy, corticobasal degeneration, argyrophilic grain disease, globular glial tauopathies and conditions associated with specific MAPT mutations. In these diseases, 4R-tau deposits are found in various cell types and anatomical regions of the brain and the conditions share pathological, pathophysiological and clinical characteristics. Despite being considered 'prototype' tauopathies and, therefore, ideal for studying neuroprotective agents, 4R-tauopathies are still severe and untreatable diseases for which no validated biomarkers exist. However, advances in research have addressed the issues of phenotypic overlap, early clinical diagnosis, pathophysiology and identification of biomarkers, setting a road map towards development of treatments. New clinical criteria have been developed and large cohorts with early disease are being followed up in prospective studies. New clinical trial readouts are emerging and biomarker research is focused on molecular pathways that have been identified. Lessons learned from failed trials of neuroprotective drugs are being used to design new trials. In this Review, we present an overview of the latest research in 4R-tauopathies, with a focus on progressive supranuclear palsy, and discuss how current evidence dictates ongoing and future research goals.

iPS Cell-Based Model for MAPT Haplotype as a Risk Factor for Human Tauopathies Identifies No Major Differences in TAU Expression

The H1 haplotype of the microtubule-associated protein tau (MAPT) gene is a common genetic risk factor for some neurodegenerative diseases such as progressive supranuclear palsy, corticobasal degeneration, and Parkinson's disease. The molecular mechanism causing the increased risk for the named diseases, however, remains unclear. In this paper, we present a valuable tool of eight small molecule neural precursor cell lines (smNPC) homozygous for the MAPT haplotypes (four H1/H1 and four H2/H2 cell lines), which can be used to identify MAPT-dependent phenotypes. The employed differentiation protocol is fast due to overexpression of NEUROGENIN-2 and therefore suitable for high-throughput approaches. A basic characterization of all human cell lines was performed, and their TAU and α-SYNUCLEIN profiles were compared during a differentiation time of 30 days. We could identify higher levels of conformationally altered TAU in cell lines carrying the H2 haplotype. Additionally, we found increased expression levels of α-SYNUCLEIN in H1/H1 cells. With this resource, we aim to fill a gap in neurodegenerative disease modeling with induced pluripotent stem cells (iPSC) for sporadic tauopathies.

Cellular and pathological heterogeneity of primary tauopathies

Microtubule-associated protein tau is abnormally aggregated in neuronal and glial cells in a range of neurodegenerative diseases that are collectively referred to as tauopathies. Multiple studies have suggested that pathological tau species may act as a seed that promotes aggregation of endogenous tau in naïve cells and contributes to propagation of tau pathology. While they share pathological tau aggregation as a common feature, tauopathies are distinct from one another with respect to predominant tau isoforms that accumulate and the selective vulnerability of brain regions and cell types that have tau inclusions. For instance, primary tauopathies present with glial tau pathology, while it is mostly neuronal in Alzheimer's disease (AD). Also, morphologies of tau inclusions can greatly vary even within the same cell type, suggesting distinct mechanisms or distinct tau conformers in each tauopathy. Neuropathological heterogeneity across tauopathies challenges our understanding of pathophysiology behind tau seeding and aggregation, as well as our efforts to develop effective therapeutic strategies for AD and other tauopathies. In this review, we describe diverse neuropathological features of tau inclusions in neurodegenerative tauopathies and discuss what has been learned from experimental studies with mouse models, advanced transcriptomics, and cryo-electron microscopy (cryo-EM) on the biology underlying cell type-specific tau pathology.

Environmental Risk Factors for Progressive Supranuclear Palsy

Typically, progressive supranuclear palsy (PSP) is clinically characterized by slow vertical saccades or supranuclear gaze palsy, levodopa-resistant parkinsonism with predominant axial symptoms, and cognitive executive impairment. Over the past decades, various PSP phenotypes, including PSP with predominant parkinsonism, PSP with corticobasal syndrome, PSP with progressive gait freezing, and PSP with predominant frontal dysfunction, have been identified from pathologically confirmed cases. Expanding knowledge led to new diagnostic criteria for PSP that with increased disease awareness led to increased PSP prevalence estimates. The identification of environmental and modifiable risk factors creates an opportunity to intervene and delay the onset of PSP or slow disease progression. To date, despite the increasing number of publications assessing risk factors for PSP, few articles have focused on environmental and lifestyle risk factors for this disorder. In this article, we reviewed the literature investigating the relationship between PSP and several environmental and other modifiable lifestyle risk factors. In our review, we found that exposures to toxins related to diet, metals, well water, and hypertension were associated with increased PSP risk. In contrast, higher education and statins may be protective. Further case-control studies are encouraged to determine the exact role of these factors in the etiopathogenesis of PSP, which in turn would inform strategies to prevent and reduce the burden of PSP.

Study on reversal of ABCB1 mediated multidrug resistance in Colon cancer by acetogenins: An in-silico approach

Multi-Drug Resistance (MDR) exerted by tumor cells is majorly due to the overexpression of ATP Binding cassette transporters such as ABCB1/P-glycoprotein (P-gp). Annonaceous acetogenins (AGEs) exert anticancer activity by strongly inhibiting NADH oxidase of cancer cells. The present in silico study aims at screening a potent MDR inhibitor among acetogenins from the plant Annona muricata. Twenty-four AGEs were selected and screened for their pharmacokinetic properties. An inward facing conformation of P-gp is required for understanding the interaction of AGEs at the drug binding region and hence the human P-gp protein was modeled. The selected compounds were then docked with the ATP binding site and the drug binding site of modeled human P-gp. Annonacin A.1, Annohexocin.1 and Annomuricin E.1 docked better with high MM/GBSA dG binding in the drug binding region as compared with the conventional drugs. These compounds had a better docking score as compared with control inhibitor drugs at the ATP binding region. The complexes were subjected to MD simulation and Annonacin A was stable throughout the simulation period. Therefore, Annonacin A might act as a competitive inhibitor for the chemo drugs for binding at the drug binding region of P-gp. Hence it is capable of decreasing the efflux of chemo drugs out of the cells by P-Glycoprotein/ABCB1/MDR1. With this computational study, it is concluded that this compound might potentially reverse MDR, and hence can be taken forward for validation studies.Communicated by Ramaswamy H. Sarma.

Seven Solutions for Neuroprotection in Parkinson's Disease

Parkinson's disease (PD) is a neurodegenerative disorder characterized by loss of dopaminergic neurons in the substantia nigra and accumulation of iron and alpha-synuclein; it follows a characteristic pattern throughout the nervous system. Despite decades of successful preclinical neuroprotective studies, no drug has then shown efficacy in clinical trials. Considering this dilemma, we have reviewed and organized solutions of varying importance that can be exclusive or additive, and we outline approaches to help generate successful development of neuroprotective drugs for PD: (1) select patients in which the targeted mechanism is involved in the pathological process associated with the monitoring of target engagement, (2) combine treatments that target multiple pathways, (3) establish earliest interventions and develop better prodromal biomarkers, (4) adopt rigorous methodology and specific disease-relevant designs for disease-modifying clinical trials, (5) customize drug with better brain biodistribution, (6) prioritize repurposed drugs as a first line approach, and (7) adapt preclinical models to the targeted mechanisms with translational biomarkers to increase their predictive value. © 2020 International Parkinson and Movement Disorder Society.

Revalorization of bioactive compounds from tropical fruit by-products and industrial applications by means of sustainable approaches

Tropical fruits trade is on the rise due to the claimed health benefits related with their consumption. Functional activities are exerted by the presence of bioactive compounds which could be used for prevention or amelioration diseases. However, the occurrence of bioactive compounds is found mainly in non-edible fraction of tropical fruits which are usually discarded. Therefore, the revalorization of tropical fruits by-products as source of functional compounds is on the cutting-edge research. The implementation of this challenge not only allows the enhancement of the tropical fruits by-products management, but also the production of value-added products. This review compiles the latest comprehensive information about the revalorization of bioactive compounds from tropical fruits by-products. A revision of the sustainable green technologies used for the isolation of valuable compounds has been carried out as well as the current food, functional, cosmeceutical and bioenergetics industrial applications of bioactive compounds extracted from tropical fruits by-products.

Acetogenins from Annonaceae family. Their potential biological applications

The aim of this contribution has been to continue with the knowledge about newly isolated acetogenins from Annonaceae family for the last fifteen years. This review will report classification, extraction, isolation, elucidation of the structure, biological activities and mechanism of action of such interesting natural products. In fact, out of the 532 compounds reviewed, 115 previously non-described annonaceous acetogenins have been added to the list of isolated compounds from 2005 to May 2019.

Xenobiotics, Trace Metals and Genetics in the Pathogenesis of Tauopathies

Tauopathies are a disease group characterized by either pathological accumulation or release of fragments of hyperphosphorylated tau proteins originating from the central nervous system. The tau hypotheses of Parkinson’s and Alzheimer’s diseases contain a clinically diverse spectrum of tauopathies. Studies of case records of various tauopathies may reveal clinical phenotype characteristics of the disease. In addition, improved understanding of different tauopathies would disclose environmental factors, such as xenobiotics and trace metals, that can precipitate or modify the progression of the disorder. Important for diagnostics and monitoring of these disorders is a further development of adequate biomarkers, including refined neuroimaging, or proteomics. Our goal is to provide an in-depth review of the current literature regarding the pathophysiological roles of tau proteins and the pathogenic factors leading to various tauopathies, with the perspective of future advances in potential therapeutic strategies.

Frontrunner in Translation: Progressive Supranuclear Palsy

Progressive supranuclear palsy (PSP) is a four-repeat tau proteinopathy. Abnormal tau deposition is not unique for PSP and is the basic pathologic finding in some other neurodegenerative disorders such as Alzheimer's disease (AD), age-related tauopathy, frontotemporal degeneration, corticobasal degeneration, and chronic traumatic encephalopathy. While AD research has mostly been focused on amyloid beta pathology until recently, PSP as a prototype of a primary tauopathy with high clinical-pathologic correlation and a rapid course is a crucial candidate for tau therapeutic research. Several novel approaches to slow disease progression are being developed. It is expected that the benefits of translational research in this disease will extend beyond the PSP population. This article reviews advances in the diagnosis, epidemiology, pathology, hypothesized etiopathogenesis, and biomarkers and disease-modifying therapeutic approaches of PSP that is leading it to become a frontrunner in translation.

Food toxins and the Caribbean Parkinson plus types

In the 90's, clinico pathological studies have considerably improved the diagnosis of specific and rare neurodegenerative diseases. After a training in Parkinsons' disease in Paris, the author moved to French West Indies (Guadeloupe) and observed a high incidence of atypical parkinsonism with dementia, unresponsive to levodopa. Similar features were observed in Martinique. An environmental origin has been suspected with the exposure to toxins of annonaceae leaves and seeds. The candidate toxins are acetogenins acting as mitochondrial poison. This was demonstrated in neuronal cell cultures, and in animals. However, the agency for food security did not conclude that Annonaceae should not be used for herbal (medicinal) tea, even if the population is now aware about the possible risk of parkinsonism after exposure to annonaceae acetogenins.

Four-repeat tauopathies

Tau is a microtubule-associated protein with versatile functions in the dynamic assembly of the neuronal cytoskeleton. Four-repeat (4R-) tauopathies are a group of neurodegenerative diseases defined by cytoplasmic inclusions predominantly composed of tau protein isoforms with four microtubule-binding domains. Progressive supranuclear palsy, corticobasal degeneration, argyrophilic grain disease or glial globular tauopathy belong to the group of 4R-tauopathies. The present review provides an introduction in the current concept of 4R-tauopathies, including an overview of the neuropathological and clinical spectrum of these diseases. It describes the genetic and environmental etiological factors, as well as the contemporary knowledge about the pathophysiological mechanisms, including post-translational modifications, aggregation and fragmentation of tau, as well as the role of protein degradation mechanisms. Furthermore, current theories about disease propagation are discussed, involving different extracellular tau species and their cellular release and uptake mechanisms. Finally, molecular diagnostic tools for 4R-tauopathies, including tau-PET and fluid biomarkers, and investigational therapeutic strategies are presented. In summary, we report on 4R-tauopathies as overarching disease concept based on a shared pathophysiological concept, and highlight the challenges and opportunities on the way towards a causal therapy.

Dietary Variations in a Multiethnic Parkinson's Disease Cohort and Possible Influences on Nonmotor Aspects: A Cross-Sectional Multicentre Study

Dietary habits may differ between Parkinson's disease (PD) patients of different ethnicities. The primary aim of this cross-sectional analysis was to compare dietary habits in a multiethnic PD population and investigate potential nonmotor differences. All patients completed a dietary habits questionnaire. Besides basic demographics, patients' motor involvement (Hoehn and Yahr (HY)) and nonmotor symptoms (Nonmotor Symptoms Scale; Hospital Anxiety and Depression Scale) were assessed. 139 PD patients were included (mean age 66.8 ± 11.6 years; 61.2% male; mean disease duration 6.2 ± 5.2 years; median HY 3): 47.5% were White, 24.5% Asian, and 28.0% Black African and Caribbean (BAC). We found dietary differences between the groups, including a greater frequency of vegetarians and greater consumption of cumin, turmeric, and cinnamon as well as lower consumption of beef in Asian patients than in White and BAC and greater consumption of chili than in White patients and higher consumption of pork in White than Asian and BAC patients. There were no significant differences in dietary supplement consumption after correction for multiple comparisons. None of the dietary factors examined were associated with differences in nonmotor symptoms. Diet and supplement use vary in PD patients across ethnicities, this is both a problem and opportunity for nutritional medicine research. These data support the importance of considering ethnic diversity as part of recruitment strategy in nutrition and clinical studies.

Potential therapeutic applications of the genus Annona: Local and traditional uses and pharmacology

ETHNO-PHARMACOLOGICAL RELEVANCE

Annona species (Annonaceae) have long been used as traditional herbal medicines by native peoples in tropical areas. In different countries they are used against a large variety of illnesses, such as parasitic and infectious diseases, cancer, diabetes, peptic ulcers, and mental disorders.

AIM OF THE STUDY

This review aims to achieve a comprehensive understanding of the research conducted so far on the local and traditional uses, pharmacological activities, mechanism of actions of active compounds, toxicity, and possible interactions with other drugs of the Annona species. Through analysis of these findings, evidences supporting their applications in ethno-medicines are described. We discuss the possible research opportunities and stand out the weak points in our knowledge that deserves further investigation.

MATERIAL AND METHODS

Information on ethno-medicinal uses and pharmacological activities of the Annona genus was collected. The main scientific biomedical literature databases (Cochrane, PubMed, Scopus, Lilacs, SeCiMed, Elsevier, SpringerLink, Google Scholar, SciFinder) were consulted. The search covered all the literature available until September 2017. National and regional databases of Herbal Medicine and Complementary and Alternative Medicine were also revised in order to explore further data. For a better understanding of the therapeutic importance of these species, we have classified the pharmacological activities within each group of disorders. The International Classification of Diseases (ICD), used from WHO Member States, was chosen as the reference classification.

RESULTS

From among the 27 species revised, four species are highlighted for their important pharmacological activities in most of the groups of illnesses: A. muricata, A. squamosa, A. senegalensis, and A. cherimola. Many investigations have been performed with extracts from the leaves, bark, fruit and seeds and have shown a wide range of pharmacological activities, such as antiprotozoal, antitumoural, antidiabetic, hepato-protective, anti-inflammatory and anxiolytic activities. The chemistry on the annonaceous acetogenins (ACGs) has been extensively investigated due to their potent antitumoural activity. Many of the assays were carried out with the isolated acetogenins in different lines of tumour culture cells and were found effective at very low doses even in multidrug-resistant tumours, and hence constitute promising compounds in the treatment of different types of cancers. No studies were found with extracts rich in acetogenins in the clinical field.

CONCLUSIONS

The experimental results from the pharmacological research enable the validation of their traditional uses in several of the groups of diseases in the countries of origin and reveal these plants to be a valuable source for therapeutic molecules. However, more toxicity assays and clinical trials would be necessary to establish optimal and safe doses of consumption on the application of these medicinal plants.

Annona muricata Leaf Extract Triggered Intrinsic Apoptotic Pathway to Attenuate Cancerous Features of Triple Negative Breast Cancer MDA-MB-231 Cells

Annona muricata L., known as graviola, is an evergreen plant of the tropical regions and is a rich source of natural products. Graviola has various biological activities, and it is best known for its anticancer activity. This study aimed to investigate the effects of crude graviola extract in vitro on breast cancer cells; in particular, we aimed to identify an agent against triple negative breast cancer (TNBC). We used the TNBC MDA-MB-231 cell line as the experimental model and the ER(+) non-TNBC MCF-7 breast cancer cell line as the control. We identified annonaceous acetogenins, including annonacin isomers, characteristic to this plant by using liquid chromatography tandem mass spectrometry (LC/MS/MS). We observed a significant decrease in the cell viability in both cell lines within 48 h, whereas impaired cell motility and invasiveness were observed only in the MDA-MB-231 cell line. While the MCF-7 cells showed an ER-dependent mechanism of apoptosis, the apoptosis of MDA-MB-231 cells was governed by an intrinsic apoptotic pathway triggered by graviola leaf extract (GLE).

Exploring the Leaves of Annona muricata L. as a Source of Potential Anti-inflammatory and Anticancer Agents

The use of anti-inflammatory natural products to treat inflammatory disorders for cancer prevention and therapy is an appealing area of interest in the last decades. Annona muricata L. is one of the many plant extracts that have been explored owing to their anti-inflammatory and anticancer effects. Different parts of A. muricata especially the leaves have been used for various ethnomedicinal purposes by traditional healers to treat several diseases including cancer, inflammation, diabetes, liver diseases, and abscesses. Some of these experience-based claims on the use of the plant have been transformed into evidence-based information by scientific investigations. The leaves of the plant have been extensively investigated for its diverse pharmacological aspects and found eminent for anti-inflammatory and anticancer properties. However, most studies were not on the bioactive isolates which were responsible for the activities but were based on crude extracts of the plant. In this comprehensive review, all significant findings from previous investigations till date on the leaves of A. muricata, specifically on their anti-inflammatory and anticancer activities have been compiled. The toxicology of the plant which has been shown to be due to the presence of neurotoxic annaceous acetogenins and benzyltetrahydro-isoquinoline alkaloids has also been updated to provide recent information on its safety aspects. The present knowledge of the plant has been critically assessed, aimed at providing direction toward improving its prospect as a source of potential anti-inflammatory and anticancer agents. The analysis will provide a new path for ensuring research on this plant to discover new agents to treat inflammatory diseases and cancer. Further in vitro and in vivo studies should be carried out to explore the molecular mechanisms underlying their anti-inflammatory responses in relation to anticancer activity and more detail toxicity study to ensure they are safe for human consumption. Sufficient preclinical data and safety data generated will allow clinical trials to be pursued on this plant and its bioactive compounds.

Functionalized liposomes and phytosomes loading Annona muricata L. aqueous extract: Potential nanoshuttles for brain-delivery of phenolic compounds

BACKGROUND

Multi-target drugs have gained significant recognition for the treatment of multifactorial diseases such as depression. Under a screening study of multi-potent medicinal plants with claimed antidepressant-like activity, the phenolic-rich Annona muricata aqueous extract (AE) emerged as a moderate monoamine oxidase A (hMAO-A) inhibitor and a strong hydrogen peroxide (H₂O₂) scavenger.

PURPOSE

In order to protect this extract from gastrointestinal biotransformation and to improve its permeability across the blood-brain barrier (BBB), four phospholipid nanoformulations of liposomes and phytosomes functionalized with a peptide ligand promoting BBB crossing were produced.

METHODS

AE and nanoformulations were characterized by HPLC-DAD-ESI-MSⁿ, HPLC-DAD, spectrophotometric, fluorescence and dynamic light scattering methods. Cytotoxicity and permeability studies were carried out using an in vitro transwell model of the BBB, composed of immortalized human microvascular endothelial cells (hCMEC/D3), and in vitro hMAO-A inhibition and H₂O₂ scavenging activities were performed with all samples.

RESULTS

The encapsulation/binding of AE was more efficient with phytosomes, while liposomes were more stable, displaying a slower extract release over time. In general, phytosomes were less toxic than liposomes in hCMEC/D3 cells and, when present, cholesterol improved the permeability across the cell monolayer of all tested nanoformulations. All nanoformulations conserved the antioxidant potential of AE, while phosphatidylcholine interfered with MAO-A inhibition assay.

CONCLUSIONS

Overall, phytosome formulations registered the best performance in terms of binding efficiency, enzyme inhibition and scavenging activity, thus representing a promising multipotent phenolic-rich nanoshuttle for future in vivo depression treatment.

Mitochondria: A Common Target for Genetic Mutations and Environmental Toxicants in Parkinson's Disease

Parkinson's disease (PD) is a devastating neurological movement disorder. Since its first discovery 200 years ago, genetic and environmental factors have been identified to play a role in PD development and progression. Although genetic studies have been the predominant driving force in PD research over the last few decades, currently only a small fraction of PD cases can be directly linked to monogenic mutations. The remaining cases have been attributed to other risk associated genes, environmental exposures and gene-environment interactions, making PD a multifactorial disorder with a complex etiology. However, enormous efforts from global research have yielded significant insights into pathogenic mechanisms and potential therapeutic targets for PD. This review will highlight mitochondrial dysfunction as a common pathway involved in both genetic mutations and environmental toxicants linked to PD.

A Review on Annona squamosa L.: Phytochemicals and Biological Activities

Annona squamosa L. (Annonaceae) is a fruit tree with a long history of traditional uses. A. squamosa is an evergreen plant mainly located in tropical and subtropical regions. Srikayas, the fruits of A. squamosa, are extensively used to prepare candies, ice creams and beverages. A wide range of ethno-medicinal uses has been related to different portions of A. squamosa, such as tonic, apophlegmatisant, cool medicine, abortient and heart sedative. Numerous research projects on A. squamosa have found that it has anticancer, anti-oxidant, antidiabetic, antihypertensive, hepatoprotective, antiparasitic, antimalarial, insecticidal, microbicidel and molluscicidal activities. Phytochemistry investigations on A. squamosa have considered annonaceous acetogenins (ACGs), diterpenes (DITs), alkaloids (ALKs) and cyclopeptides (CPs) as the main constituents. Until 2016, 33 DITs, 19 ALKs, 88 ACGs and 13 CPs from this species were reported. On the basis of the multiple researches on A. squamosa, this review strives to integrate available information on its phytochemicals, folklore uses and bioactivities, hoping to promote a better understanding of its medicinal values.

Clinical effects of chemical exposures on mitochondrial function

Mitochondria are critical for the provision of ATP for cellular energy requirements. Tissue and organ functions are dependent on adequate ATP production, especially when energy demand is high. Mitochondria also play a role in a vast array of important biochemical pathways including apoptosis, generation and detoxification of reactive oxygen species, intracellular calcium regulation, steroid hormone and heme synthesis, and lipid metabolism. The complexity of mitochondrial structure and function facilitates its diverse roles but also enhances its vulnerability. Primary disorders of mitochondrial bioenergetics, or Primary Mitochondrial Diseases (PMD) are due to inherited genetic defects in the nuclear or mitochondrial genomes that result in defective oxidative phosphorylation capacity and cellular energy production. Secondary mitochondrial dysfunction is observed in a wide range of diseases such as Alzheimer's and Parkinson's disease. Several lines of evidence suggest that environmental exposures cause substantial mitochondrial dysfunction. Whereby literature from experimental and human studies on exposures associated with Alzheimer's and Parkinson's diseases exist, the significance of exposures as potential triggers in Primary Mitochondrial Disease (PMD) is an emerging clinical question that has not been systematically studied.

Progressive supranuclear palsy (PSP): Richardson syndrome and other PSP variants

Phenotypic heterogeneity of progressive supranuclear palsy (PSP) has been increasingly reported in the literature and can be the source of incorrect clinical diagnosis particularly in the early stages of the disease when the classically associated symptoms of early falls and supranuclear gaze palsy may not be apparent. In addition to Richardson syndrome (RS), several atypical clinical phenotypes have been described. Advances in genetic, neuroimaging, and biochemical/molecular technologies contribute to the identification of these clinical subtypes in the context of typical PSP pathological findings. Our goal is to review the phenomenology reported in the literature that is associated with confirmed histopathological changes consistent with a PSP diagnosis and to highlight the clinical spectrum of PSP. A systematic review of the literature in PubMed through July 2015 using MeSH terms and key words related to PSP was conducted. Articles describing PSP classifications, diagnostic criteria, and case reports were reviewed and summarized. Additional PSP phenotypes not seen in recent clinicopathological studies are included. These include primary lateral sclerosis, pallido-nigro-luysian degeneration, axonal dystrophy, and multiple system atrophy in the spectrum of atypical PSP variants beyond the traditionally classified PSP subtypes. This review is intended to help with the diagnostic challenges of atypical PSP variants. We believe that large multicenter clinicopathological studies will help expand our understanding of etiology and specific mechanisms of neurodegeneration and will aid in the appropriate interpretation of outcomes when conducting clinical and basic science research.

Acetogenins from Annonaceae

In recent decades, annonaceous acetogenins have become highly studied plant secondary metabolites in terms of their isolation, structure elucidation, synthesis, biological evaluation, mechanism of action, and toxicity. The aim of the present contribution is to summarize chemical and biological reports published since 1997 on annonaceous acetogenins and synthetic acetogenin mimics. The compounds are considered biologically in terms of their cytotoxicity for cancer cell lines, neurotoxicity, pesticidal effects, and miscellaneous activities.

Neurotoxicity of Dietary Supplements from Annonaceae Species

Dietary supplements containing plant materials of Annonaceae species (Annona muricata L., A. squamosa L., A. mucosa JACQ., A. squamosa × cherimola Mabb.) were extracted by hot, pressurized ethyl acetate and analyzed for their effect in vitro on Lund human mesencephalic neurons. Cell viability was measured by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, and cell death was determined by lactate dehydrogenase levels. Three supplements strongly decreased the cell viability at extract concentrations of 1 µg/mL, of which 1 decreased cell viability at 0.1 µg/µL. Also, strong neuronal toxicities of these supplements were found. Cell death was observed at concentrations of 10 µg/mL. The degree of toxicity was comparable to the ones found in Annonaceous fruit extracts. Two fruit pulps of Annonaceae (A. muricata and A. squamosa) showed a reduction in cell viability at lower concentrations. The fruit pulp extract of A. muricata revealed the strongest neurotoxic effect, with 67% cell death at a concentration of 1 µg/mL. A high reduction in cell viability coupled with pronounced cell death was found at 0.1 µg/mL for an Annonaceous seed extract. These results demonstrate that the intake of dietary supplements containing plant material from Annonaceae may be hazardous to health in terms of neurotoxicity.

A geographical cluster of progressive supranuclear palsy in northern France

OBJECTIVE

To describe a cluster of progressive supranuclear palsy (PSP) in northern France. PSP has not been reported in geographical, temporal, or occupational clusters. A unit of Neurology and Neurogeriatrics opened in 2005 at the Centre Hospitalier de Wattrelos, serving the population of Wattrelos and Leers (combined population 51,551) and parts of neighboring towns. For most of the 20th century, this area was a center for chromate and phosphate ore processing, textile dyeing, and tanning. Significant industrial waste persists close to residential areas.

METHODS

From 2005 to 2014, 92 patients with PSP at Centre Hospitalier de Wattrelos were identified and studied. Detailed residential data were available in the medical records. Eighty cases have had magnetic resonance head scanning and 60 have died, of whom 13 have been examined neuropathologically.

RESULTS

The ratio of observed to expected PSP incidence over the period 2005 to 2012 was 12.3 (95% confidence interval: 7.4-35.9). Mean onset age was 74.3 years. The Richardson syndrome/PSP-parkinsonism ratio was 43%/42%. Four other phenotypes each occurred in 2% to 5%. Onset was gait/balance difficulty in 52%. None of the 92 affected patients were relatives and 7 were of North African ancestry. MRI was compatible with a clinical diagnostic of PSP in all cases. Histopathologic examination confirmed neurofibrillary degeneration and tufted astrocytes in all autopsied cases. Western blots revealed a typical tau 4R doublet. The tau H1 haplotype occurred in 95.8% of cases' chromosomes.

CONCLUSIONS

We have identified a cluster of PSP in a geographical area with severe environmental contamination by industrial metals.

Annona muricata (Annonaceae): A Review of Its Traditional Uses, Isolated Acetogenins and Biological Activities

Annona muricata is a member of the Annonaceae family and is a fruit tree with a long history of traditional use. A. muricata, also known as soursop, graviola and guanabana, is an evergreen plant that is mostly distributed in tropical and subtropical regions of the world. The fruits of A. muricata are extensively used to prepare syrups, candies, beverages, ice creams and shakes. A wide array of ethnomedicinal activities is contributed to different parts of A. muricata, and indigenous communities in Africa and South America extensively use this plant in their folk medicine. Numerous investigations have substantiated these activities, including anticancer, anticonvulsant, anti-arthritic, antiparasitic, antimalarial, hepatoprotective and antidiabetic activities. Phytochemical studies reveal that annonaceous acetogenins are the major constituents of A. muricata. More than 100 annonaceous acetogenins have been isolated from leaves, barks, seeds, roots and fruits of A. muricata. In view of the immense studies on A. muricata, this review strives to unite available information regarding its phytochemistry, traditional uses and biological activities.