Artemisinin reduces the level of antibodies to gliadin in schizophrenia

New clinical application prospects of artemisinin and its derivatives: a scoping review

BACKGROUND

Recent research has suggested that artemisinin and its derivatives may have therapeutic effects on parasites, viruses, tumors, inflammation and skin diseases. This study aimed to review clinical research on artemisinin and its derivatives except anti-malaria and explore possible priority areas for future development.

METHODS

Relevant articles in English and Chinese published before 28 October 2021 were reviewed. All articles were retrieved and obtained from databases including WanFang, PubMed/MEDLINE, the Cochrane Library, China National Knowledge International, Embase, OpenGrey, the Grey Literature Report, Grey Horizon, and ClinicalTrials.gov. Studies were selected for final inclusion based on predefined criteria. Information was then extracted and analyzed by region, disease, outcome, and time to identify relevant knowledge gaps.

RESULTS

Seventy-seven studies on anti-parasitic (35), anti-tumor (16), anti-inflammatory (12), anti-viral (8), and dermatological treatments (7) focused on the safety and efficacy of artemisinin and its derivatives. The anti-parasitic clinical research developed rapidly, with a large number of trials, rapid clinical progress, and multiple research topics. In contrast, anti-viral research was limited and mainly stayed in phase I clinical trials (37.50%). Most of the studies were conducted in Asia (60%), followed by Africa (27%), Europe (8%), and the Americas (5%). Anti-parasite and anti-inflammatory research were mainly distributed in less developed continents such as Asia and Africa, while cutting-edge research such as anti-tumor has attracted more attention in Europe and the United States. At the safety level, 58 articles mentioned the adverse reactions of artemisinin and its derivatives, with only one study showing a Grade 3 adverse event, while the other studies did not show any related adverse reactions or required discontinuation. Most studies have discovered therapeutic effects of artemisinin or its derivatives on anti-parasitic (27), anti-tumor (9), anti-inflammatory (9) and dermatological treatment (6). However, the efficacy of artemisinin-based combination therapies (ACTs) for parasitic diseases (non-malaria) is still controversial.

CONCLUSIONS

Recent clinical studies suggest that artemisinin and its derivatives may be safe and effective candidates for anti-tumor, anti-parasitic, anti-inflammatory and dermatological drugs. More phase II/III clinical trials of artemisinin and its derivatives on antiviral effects are needed.

Anti-malaria drug artesunate prevents development of amyloid-β pathology in mice by upregulating PICALM at the blood-brain barrier

BACKGROUND

PICALM is one of the most significant susceptibility factors for Alzheimer's disease (AD). In humans and mice, PICALM is highly expressed in brain endothelium. PICALM endothelial levels are reduced in AD brains. PICALM controls several steps in Aβ transcytosis across the blood-brain barrier (BBB). Its loss from brain endothelium in mice diminishes Aβ clearance at the BBB, which worsens Aβ pathology, but is reversible by endothelial PICALM re-expression. Thus, increasing PICALM at the BBB holds potential to slow down development of Aβ pathology.

METHODS

To identify a drug that could increase PICALM expression, we screened a library of 2007 FDA-approved drugs in HEK293t cells expressing luciferase driven by a human PICALM promoter, followed by a secondary mRNA screen in human Eahy926 endothelial cell line. In vivo studies with the lead hit were carried out in Picalm-deficient (Picalm+/-) mice, Picalm+/-; 5XFAD mice and Picalmlox/lox; Cdh5-Cre; 5XFAD mice with endothelial-specific Picalm knockout. We studied PICALM expression at the BBB, Aβ pathology and clearance from brain to blood, cerebral blood flow (CBF) responses, BBB integrity and behavior.

RESULTS

Our screen identified anti-malaria drug artesunate as the lead hit. Artesunate elevated PICALM mRNA and protein levels in Eahy926 endothelial cells and in vivo in brain capillaries of Picalm+/- mice by 2-3-fold. Artesunate treatment (32 mg/kg/day for 2 months) of 3-month old Picalm+/-; 5XFAD mice compared to vehicle increased brain capillary PICALM levels by 2-fold, and reduced Aβ42 and Aβ40 levels and Aβ and thioflavin S-load in the cortex and hippocampus, and vascular Aβ load by 34-51%. Artesunate also increased circulating Aβ42 and Aβ40 levels by 2-fold confirming accelerated Aβ clearance from brain to blood. Consistent with reduced Aβ pathology, treatment of Picalm+/-; 5XFAD mice with artesunate improved CBF responses, BBB integrity and behavior on novel object location and recognition, burrowing and nesting. Endothelial-specific knockout of PICALM abolished all beneficial effects of artesunate in 5XFAD mice indicating that endothelial PICALM is required for its therapeutic effects.

CONCLUSIONS

Artesunate increases PICALM levels and Aβ clearance at the BBB which prevents development of Aβ pathology and functional deficits in mice and holds potential for translation to human AD.

Therapeutic Implications of the Microbial Hypothesis of Mental Illness

There is increasingly compelling evidence that microorganisms may play an etiological role in the emergence of mental illness in a subset of the population. Historically, most work has focused on the neurotrophic herpesviruses, herpes simplex virus type 1 (HSV-1), cytomegalovirus (CMV), and Epstein-Barr virus (EBV) as well as the protozoan, Toxoplasma gondii. In this chapter, we provide an umbrella review of this literature and additionally highlight prospective studies that allow more mechanistic conclusions to be drawn. Next, we focus on clinical trials of anti-microbial medications for the treatment of psychiatric disorders. We critically evaluate six trials that tested the impact of anti-herpes medications on inflammatory outcomes in the context of a medical disorder, nine clinical trials utilizing anti-herpetic medications for the treatment of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) or schizophrenia, and four clinical trials utilizing anti-parasitic medications for the treatment of schizophrenia. We then turn our attention to evidence for a gut dysbiosis and altered microbiome in psychiatric disorders, and the potential therapeutic effects of probiotics, including an analysis of more than 10 randomized controlled trials of probiotics in the context of schizophrenia, bipolar disorder (BD), and major depressive disorder (MDD).

Impact of Plant-Based Foods and Nutraceuticals on Toxoplasma gondii Cysts: Nutritional Therapy as a Viable Approach for Managing Chronic Brain Toxoplasmosis

Toxoplasma gondii is an obligate intracellular parasite that mainly infects warm-blooded animals including humans. T. gondii can encyst and persist chronically in the brain, leading to a broad spectrum of neurological sequelae. Despite the associated health threats, no clinical drug is currently available to eliminate T. gondii cysts. In a continuous effort to uncover novel therapeutic agents for these cysts, the potential of nutritional products has been explored. Herein, we describe findings from in vitro and in vivo studies that support the efficacy of plant-based foods and nutraceuticals against brain cyst burden and cerebral pathologies associated with chronic toxoplasmosis. Finally, we discuss strategies to increase the translatability of preclinical studies and nutritional products to address whether nutritional therapy can be beneficial for coping with chronic T. gondii infections in humans.

The gut-microbiome as a target for the treatment of schizophrenia: A systematic review and meta-analysis of randomised controlled trials of add-on strategies

The gut-microbiome has been hypothesised as a novel potential target for intervention for schizophrenia. We tested this hypothesis with a systematic review and meta-analysis of studies investigating the efficacy and acceptability of add-on strategies known to affect the gut-microbiome for the treatment of schizophrenia. Following PRISMA guidelines, we searched from inception to August 2019 all the randomised double-blind controlled trials of add-on antibiotics, antimicrobials, pre/probiotics, and faecal transplant in schizophrenia. Primary outcomes were severity of negative symptoms and acceptability of treatment. Data were independently extracted by multiple observers and a random-mixed model was used for the analysis. Heterogeneity was assessed with the I² index. We identified 28 eligible trials: 21 investigated antibiotics, 4 antimicrobials (Artemisinin, Artemether, and Sodium Benzoate), 3 pre/probiotics, none faecal transplant. Results showed no effect of D-Cycloserine (10 studies; SMD, -0.16; 95% CI -0.40, 0.08; P = .20; I²: 28.2%), Minocycline (7 studies; SMD: -0.35; 95% CI -0.70, 0.00; P = .05, I²:77.7%), other antibiotics (2 studies), probiotics alone (1 study), and Artemisinin (1 study) on negative symptoms of schizophrenia when compared to placebo. Limited evidence suggests efficacy on negative symptoms for Sodium benzoate (2 studies; SMD, -0.63; 95%CI -1.03, -0.23; P < .001; I²:0%), Artemether (1 study), and probiotics combined with Vitamin D (1 study) when compared to placebo. Acceptability of intervention was similar to placebo. Negative findings were mainly led by antibiotics trials, with paucity of evidence available on pre/probiotics. There is a need of expanding our knowledge on the clinical relevance of gut-microbiome-host interaction in psychosis before engaging in further trials.

The past and future of novel, non-dopamine-2 receptor therapeutics for schizophrenia: A critical and comprehensive review

Since the discovery of chlorpromazine in the 1950's, antipsychotic drugs have been the cornerstone of treatment of schizophrenia, and all attenuate dopamine transmission at the dopamine-2 receptor. Drug development for schizophrenia since that time has led to improvements in side effects and tolerability, and limited improvements in efficacy, with the exception of clozapine. However, the reasons for clozapine's greater efficacy remain unclear, despite the great efforts and resources invested therewith. We performed a comprehensive review of the literature to determine the fate of previously tested, non-dopamine-2 receptor experimental treatments. Overall we included 250 studies in the review from the period 1970 to 2017 including treatments with glutamatergic, serotonergic, cholinergic, neuropeptidergic, hormone-based, dopaminergic, metabolic, vitamin/naturopathic, histaminergic, infection/inflammation-based, and miscellaneous mechanisms. Despite there being several promising targets, such as allosteric modulation of the NMDA and α7 nicotinic receptors, we cannot confidently state that any of the mechanistically novel experimental treatments covered in this review are definitely effective for the treatment of schizophrenia and ready for clinical use. We discuss potential reasons for the relative lack of progress in developing non-dopamine-2 receptor treatments for schizophrenia and provide recommendations for future efforts pursuing novel drug development for schizophrenia.

Autoimmune phenotypes in schizophrenia reveal novel treatment targets

Typical and atypical antipsychotics are the first-line treatments for schizophrenia, but these classes of drugs are not universally effective, and they can have serious side effects that impact compliance. Antipsychotic drugs generally target the dopamine pathways with some variation. As research of schizophrenia pathophysiology has shifted away from a strictly dopamine-centric focus, the development of new pharmacotherapies has waned. A field of inquiry with centuries-old roots is gaining traction in psychiatric research circles and may represent a new frontier for drug discovery in schizophrenia. At the forefront of this investigative effort is the immune system and its many components, pathways and phenotypes, which are now known to actively engage the brain. Studies in schizophrenia reveal an intricate association of environmentally-driven immune activation in concert with a disrupted genetic template. A consistent conduit through this gene-environmental milieu is the gut-brain axis, which when dysregulated can generate pathological autoimmunity. In this review, we present epidemiological and biochemical evidence in support of an autoimmune component in schizophrenia and depict gut processes and a dysbiotic microbiome as a source and perpetuator of autoimmune dysfunction in the brain. Within this framework, we review the role of infectious agents, inflammation, gut dysbioses and autoantibody propagation on CNS pathologies such as neurotransmitter receptor hypofunction and complement pathway-mediated synaptic pruning. We then review the new pharmacotherapeutic horizon and novel agents directed to impact these pathological conditions. At the core of this discourse is the understanding that schizophrenia is etiologically and pathophysiologically heterogeneous and thus its treatment requires individualized attention with disease state variants diagnosed with objective biomarkers.

Natural Medicines for Psychotic Disorders: A Systematic Review

Patients with psychotic disorders regularly use natural medicines, although it is unclear whether these are effective and safe. The aim of this study was to provide an overview of evidence for improved outcomes by natural medicines. A systematic literature search was performed through Medline, PsycINFO, CINAHL, and Cochrane until May 2015. In 110 randomized controlled trials, evidence was found for glycine, sarcosine, N-acetylcysteine, some Chinese and ayurvedic herbs, ginkgo biloba, estradiol, and vitamin B6 to improve psychotic symptoms when added to antipsychotics. Ginkgo biloba and vitamin B6 seemed to reduce tardive dyskinesia and akathisia. Results on other compounds were negative or inconclusive. All natural agents, except reserpine, were well tolerated. Most study samples were small, study periods were generally short, and most results need replication. However, there is some evidence for beneficial effects of certain natural medicines.

Toxoplasma gondii and schizophrenia: a review of published RCTs

Over the last 60 years, accumulating evidence has suggested that acute, chronic, and maternal Toxoplasma gondii infections predispose to schizophrenia. More recent evidence suggests that chronically infected patients with schizophrenia present with more severe disease. After acute infection, parasites form walled cysts in the brain, leading to lifelong chronic infection and drug resistance to commonly used antiparasitics. Chronic infection is the most studied and closely linked with development and severity of schizophrenia. There are currently four published randomized controlled trials evaluating antiparasitic drugs, specifically azithromycin, trimethoprim, artemisinin, and artemether, in patients with schizophrenia. No trials have demonstrated a change in psychopathology with adjunctive treatment. Published trials have either selected drugs without evidence against chronic infection or used them at doses too low to reduce brain cyst burden. Furthermore, trials have failed to achieve sufficient power or account for confounders such as previous antipsychotic treatment, sex, age, or rhesus status on antiparasitic effect. There are currently no ongoing trials of anti-Toxoplasma therapy in schizophrenia despite ample evidence to justify further testing.

A review on the relationship between gluten and schizophrenia: Is gluten the cause?

INTRODUCTION

Schizophrenia is a chronic disease that possesses various clinical manifestations. It presents rather heterogeneous characteristics with respect to onset type, symptoms, and the course of the disease. Although the lifetime prevalence is as low as 1%, it can cause serious disability. Thus, it is very important to develop efficient treatment methods. In some studies, it is hypothesized that removing gluten from the diet leads to a significant improvement in disease symptoms. Epidemiological studies revealed that the prevalence of celiac disease among schizophrenic patients is almost two times higher than that of the general population.

OBJECTIVE

In this review, we evaluate the effects of gluten and celiac disease on the onset of schizophrenia. Efficacy of gluten-free diet applications, antibody response against gluten, and the interaction of the brain-gut axis and the presence of common genetic points are also investigated.

METHODS

Without any publication date restriction, Pubmed database searches were made for 'schizophrenia, gluten, gliadin, celiac disease, exorphin, brain-gut axis, psychiatric disorders.' The keywords and the articles about the schizophrenia-celiac disease relationship are included in our review.

RESULTS

Several studies presented evidence to suggest that symptoms associated with schizophrenia were minimized when gluten was excluded from patients' diets. Immunological searches revealed that most schizophrenic patients with increased anti-gliadin antibodies did not possess celiac disease; yet, the presence of increased antibodies against gliadin can be the share point of the immunological abnormalities found in both of the diseases.

DISCUSSION

There were no consistent results in the clinical, immunological, microbiological, and epidemiological studies that investigated the relationship between schizophrenia and celiac disease. This presents a need for a larger scale study to confirm the presence of this suggested correlation between schizophrenia and celiac disease. The underlying mechanisms between the two diseases should be explored.

The efficacy of herbal medicines against Toxoplasma gondii during the last 3 decades: a systematic review

The objective of the current study was to systematically review papers discussing the efficacy of medicinal herbs against Toxoplasma gondii. Data were systematically collected from published papers about the efficacy of herbs used against T. gondii globally from 1988 to 2015, from PubMed, Google Scholar, ISI Web of Science, EBSCO, Science Direct, and Scopus. Forty-nine papers were included in the current systematic review reporting the evaluation of medicinal plants against T. gondii globally, both in vitro and in vivo. Sixty-one plants were evaluated. Most of the studies were carried out on Artemisia annua. The second highest number of studies were carried out on Glycyrrhiza glabra extracts. RH and ME49 were the predominant parasite strains used. Additionally, Swiss-Webster and BALB/c mice were the major animal models used. Alcoholic and aqueous extracts were used more than other types of extracts. Natural compounds mentioned here may be developed as novel and more effective therapeutic agents that improve the treatment of toxoplasmosis due to their lower side effects, higher availability, and better cultural acceptance compared with those of the chemical drugs that are currently being used.

A longitudinal study of cognitive functioning in schizophrenia: clinical and biological predictors

BACKGROUND

Cognitive deficits are a central feature of schizophrenia but it is not certain how cognitive functioning changes over time. The purpose of this prospective longitudinal study was to determine the temporal change of cognitive functioning and the predictors of cognitive performance from among demographic, clinical, and biological variables.

METHODS

Participants were individuals with schizophrenia or schizoaffective disorder whose cognitive functioning was assessed at multiple time points with the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS). At the baseline visit participants had a blood sample drawn from which C-reactive protein, antibodies to Herpes Simplex Virus type 1, and selected genetic polymorphisms were measured. Repeated measures linear regression was used to determine whether cognitive measures changed over time and which variables predicted cognitive performance.

RESULTS

The sample consisted of 132 participants, mean age 43.7 years at baseline, who received a median of 3 cognitive assessments over a period averaging 2.8 years. The RBANS Total score and Language index showed no statistically significant temporal change; performance on two indices, Immediate Memory and Attention, showed modest but statistically significant improvements (gains of 0.89±0.33 and 0.76±0.29 points per year, respectively); Visuospatial/Constructional performance showed a modest but statistically significant decline (of 0.80±0.25 points per year). Few variables predicted cognitive performance; however greater psychiatric symptom severity was associated with worse cognitive performance for most cognitive measures.

CONCLUSIONS

Cognitive functioning in middle-aged persons with schizophrenia showed an absence of decline for most measures and modest gains in some measures.

The effect of artemether on psychotic symptoms and cognitive impairment in first-episode, antipsychotic drug-naive persons with schizophrenia seropositive to Toxoplasma gondii

The objective was to evaluate the efficacy and safety of add-on artemether in first-episode, untreated people with schizophrenia, who were Toxoplasma gondii seropositive, and explore the change in T. gondii antibodies during treatment. In this eight-week, double-blind, randomized, placebo-controlled trial, 100 T. gondii seropositive participants with schizophrenia were randomized to either the artemether or placebo group. Participants in the artemether group received 80 mg artemether once per day during the second week (days 8-14) and the fourth week (days 22-28). Participants in the placebo group received identical looking placebo capsules. Psychopathology, adverse side effects and cognitive function were measured using standardized instruments. The group × time interaction effects for the scores of the Positive and Negative Syndrome Scale (PANSS) subscales and performances on all cognitive components were not significant, only the main effect of group was significant. Compared to the placebo group, artemether group participants showed significantly greater reduction in the PANSS negative symptom scale (F(1,46) = 4.7, p = 0.03) and the Clinical Global Impressions Scale (F(1,96) = 6.2, p = 0.01) scores, but there were no significant differences in the PANSS positive symptom and general psychopathology scales (p > 0.05). There were also no significant differences between the two groups in performance on any of the Brief Assessment of Cognition in Schizophrenia (BACS) cognitive domains. The artemether-risperidone combination is safe and well tolerated, but artemether as an adjunct to risperidone does not appear to alleviate cognitive deficits of schizophrenia. Trial Registration Chinese Clinical Trial Register (ChiCTR) TRC-13003145.

Toxoplasmosis and Polygenic Disease Susceptibility Genes: Extensive Toxoplasma gondii Host/Pathogen Interactome Enrichment in Nine Psychiatric or Neurological Disorders

Toxoplasma gondii is not only implicated in schizophrenia and related disorders, but also in Alzheimer's or Parkinson's disease, cancer, cardiac myopathies, and autoimmune disorders. During its life cycle, the pathogen interacts with ~3000 host genes or proteins. Susceptibility genes for multiple sclerosis, Alzheimer's disease, schizophrenia, bipolar disorder, depression, childhood obesity, Parkinson's disease, attention deficit hyperactivity disorder (P  from  8.01E - 05  (ADHD)  to  1.22E - 71) (multiple sclerosis), and autism (P = 0.013), but not anorexia or chronic fatigue are highly enriched in the human arm of this interactome and 18 (ADHD) to 33% (MS) of the susceptibility genes relate to it. The signalling pathways involved in the susceptibility gene/interactome overlaps are relatively specific and relevant to each disease suggesting a means whereby susceptibility genes could orient the attentions of a single pathogen towards disruption of the specific pathways that together contribute (positively or negatively) to the endophenotypes of different diseases. Conditional protein knockdown, orchestrated by T. gondii proteins or antibodies binding to those of the host (pathogen derived autoimmunity) and metabolite exchange, may contribute to this disruption. Susceptibility genes may thus be related to the causes and influencers of disease, rather than (and as well as) to the disease itself.