It has been suggested that local administration of topotecan (TT) could increase its efficacy in the treatment of glioblastoma. In this context, a PLGA implant model in the form of spheres with a porous core and stiff surface, loaded with TT and CaCl(2) was developed. An array of formulations differing from each other by the type of PLGA used, the integrity of the surface, the concentrations of TT and CaCl(2) added during the preparation, and the volume of water in the PLGA mix, was prepared, screened and explored by computerized multifactorial analysis. This analysis enabled the simultaneous identification of the most influential experimental factors on the experimental responses, which were pre-determined as the efficiency of TT loading and the TT % cumulative release at 14 days. The multifactorial analysis also revealed how the interactions among the experimental factors affect the performance of the various formulations. Thus, TT concentration and its factorial interaction with the concentration of CaCl(2) added during the spheres' preparation were identified as most prominent on the loading efficiency, while the surface integrity (intact or punctured) and CaCl(2) amount in the spheres were identified as most prominent on the TT % cumulative release from the spheres. TT was found to be cytotoxic towards glioblastoma U87 MG cells, an activity which was enhanced, synergistically, in the presence of CaCl(2) (the relative viability was reduced from 36 to 28% with combination indices of 1.0, 0.37, 0.13 and 0.06 for EC(50), EC(75), EC(90) and EC(95), respectively). Interestingly, dividing the TT dose into 3 equal portions, replenished daily to the incubation medium, increased TT cytotoxicity. The relative viability was then reduced from 35 to 7% and in the presence of CaCl(2) - from 28 to 1.9%, suggesting that a local, slow input of TT could be effective in the treatment of glioblastoma by an adjacent TT implant. The increased effect of CaCl(2) on cytotoxicity was also observed when it was co-loaded into the TT spheres. In that case, the cells' viability was reduced from 72 to 27%. It is suggested that the PLGA spheres could be used for tunable local delivery of TT in post-resection adjuvant therapy of glioblastoma.

It has been suggested that local administration of topotecan (TT) could increase its efficacy in the treatment of glioblastoma. In this context, a PLGA implant model in the form of spheres with a porous core and stiff surface, loaded with TT and CaCl2 was developed. An array of formulations differing from each other by the type of PLGA used, the integrity of the surface, the concentrations of TT and CaCl2 added during the preparation, and the volume of water in the PLGA mix, was prepared, screened and explored by computerized multifactorial analysis. This analysis enabled the simultaneous identification of the most influential experimental factors on the experimental responses, which were pre-determined as the efficiency of TT loading and the TT % cumulative release at 14 days. The multifactorial analysis also revealed how the interactions among the experimental factors affect the performance of the various formulations. Thus, TT concentration and its factorial interaction with the concentration of CaCl2 added during the spheres' preparation were identified as most prominent on the loading efficiency, while the surface integrity (intact or punctured) and CaCl2 amount in the spheres were identified as most prominent on the TT % cumulative release from the spheres. TT was found to be cytotoxic towards glioblastoma U87 MG cells, an activity which was enhanced, synergistically, in the presence of CaCl2 (the relative viability was reduced from 36 to 28% with combination indices of 1.0, 0.37, 0.13 and 0.06 for EC50, EC75, EC90 and EC95, respectively). Interestingly, dividing the TT dose into 3 equal portions, replenished daily to the incubation medium, increased TT cytotoxicity. The relative viability was then reduced from 35 to 7% and in the presence of CaCl2 – from 28 to 1.9%, suggesting that a local, slow input of TT could be effective in the treatment of glioblastoma by an adjacent TT implant. The increased effect of CaCl2 on cytotoxicity was also observed when it was co-loaded into the TT spheres. In that case, the cells' viability was reduced from 72 to 27%. It is suggested that the PLGA spheres could be used for tunable local delivery of TT in post-resection adjuvant therapy of glioblastoma.

The coronavirus disease 2019 (COVID-19) pandemic stimulated both the scientific community and healthcare companies to undertake an unprecedented effort with the aim of understanding the molecular mechanisms of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and developing effective therapeutic solutions. The peculiar immune response triggered by this virus, which seems to last only few months, led to a search for alternatives such as passive immunization in addition to conventional vaccinations. Convalescent sera, monoclonal antibodies selected from the most potent neutralizing binders induced by the virus infection, recombinant human single-domain antibodies, and binders of variable scaffold and different origin have been tested alone or in combination exploiting monovalent, multivalent and multispecific formats. In this review, we analyse the state of the research in this field and present a summary of the ongoing projects finalized to identify suitable molecules for therapies based on passive immunization.

Aging is an established risk factor for vascular diseases, but vascular aging itself may contribute to the progressive deterioration of organ function. Here, we show in aged mice that vascular endothelial growth factor (VEGF) signaling insufficiency, which is caused by increased production of decoy receptors, may drive physiological aging across multiple organ systems. Increasing VEGF signaling prevented age-associated capillary loss, improved organ perfusion and function, and extended life span. Healthier aging was evidenced by favorable metabolism and body composition and amelioration of aging-associated pathologies including hepatic steatosis, sarcopenia, osteoporosis, "inflammaging" (age-related multiorgan chronic inflammation), and increased tumor burden. These results indicate that VEGF signaling insufficiency affects organ aging in mice and suggest that modulating this pathway may result in increased mammalian life span and improved overall health.

Multi-walled carbon nanotubes (MWCNTs) are promising materials for chemical gas sensing because of their high electrical and mechanical properties and significant sensitivity to changes in the local environment. However, high-content MWCNT films suffer from the low tunability of the electrical resistance, which is crucial for high chemoresistive sensing performance. This study reports the conjugation of MWCNTs and oligomers of polyaniline (PANI) doped with Ag+ or Cu2+ incorporated into a PVC/polyacrylate. MWCNTs were sonicated in n-methyl pyrro-lidine (NMP), and PANI was conjugated via a 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide and an N-hydroxysuccinimide (EDC/NHS) process. MWCNT/PANI Ag+ or Cu2+ conjugates were doped to form a coordinate bond. The doped conjugates were successfully incorporated into the PVC/polyacrylate. These MWCNT/PANI conjugates doped were exposed to different concentrations of ethylene gas to examine their feasibility for ethylene detection.

Cyclopentane modified FIT-PNA (cpFIT-PNA) probes are reported as highly emissive RNA sensors with the highest reported brightness for FIT-PNAs. Compared to FIT-PNAs, cpFIT-PNAs have improved mismatch discrimination for several pyrimidine-pyrimidine single nucleotide variants (SNVs).

Desorption electrospray ionization mass spectrometry imaging (DESI-MSI) is one of the least specimen destructive ambient ionization mass spectrometry tissue imaging methods. It enables rapid simultaneous mapping, measurement, and identification of hundreds of molecules from an unmodified tissue sample. Over the years, since its first introduction as an imaging technique in 2005, DESI-MSI has been extensively developed as a tool for separating tissue regions of various histopathologic classes for diagnostic applications. Recently, DESI-MSI has also emerged as a versatile technique that enables drug discovery and can guide the efficient development of drug delivery systems. For example, it has been increasingly employed for uncovering unique patterns of in vivo drug distribution, the discovery of potentially treatable biochemical pathways, revealing novel druggable targets, predicting therapeutic sensitivity of diseased tissues, and identifying early tissue response to pharmacological treatment. These and other recent advances in implementing DESI-MSI as the tool for the development of novel therapies are highlighted in this review.

(1) Background: Chiral nanoparticular systems have recently emerged as a compelling platform for investigating stereospecific behavior at the nanoscopic level. We describe chiroselective supramolecular interactions that occur between DNA oligonucleotides and chiral polyurea nanocapsules. (2) Methods: We employ interfacial polyaddition reactions between toluene 2,4-diisocyanate and lysine enantiomers that occur in volatile oil-in-water nanoemulsions to synthesize hollow, solvent-free capsules with average sizes of approximately 300 nm and neutral surface potential. (3) Results: The resultant nanocapsules exhibit chiroptical activity and interact differentially with single stranded DNA oligonucleotides despite the lack of surface charge and, thus, the absence of significant electrostatic interactions. Preferential binding of DNA on D-polyurea nanocapsules compared to their L-counterparts is demonstrated by a fourfold increase in capsule size, a 50% higher rise in the absolute value of negative zeta potential ($\zeta$-potential), and a three times lower free DNA concentration after equilibration with the excess of DNA. (4) Conclusions: We infer that the chirality of the novel polymeric nanocapsules affects their supramolecular interactions with DNA, possibly through modification of the surface morphology. These interactions can be exploited when developing carriers for gene therapy and theranostics. The resultant constructs are expected to be highly biocompatible due to their neutral potential and biodegradability of polyurea shells.

A redox steady state is important in maintaining vital cellular functions and is therefore homeostatically controlled by a number of antioxidative agents, the most important of which are enzymes. Oxidative Stress (OS) is associated with (or/and caused by) excessive production of damaging reactive oxygen and/or nitrogen species (ROS, RNS), which play a role in many pathologies. Because OS is a risk factor for many diseases, much effort (and money) is devoted to early diagnosis and treatment of OS. The desired benefit of the "identify (OS) and treat (by low molecular weight antioxidants, LMWA)" approach is to enable selective treatment of patients under OS. The present work aims at gaining understanding of the benefit of the antioxidants based on interrelationship between the concentration of different OS biomarkers and LMWA. Both the concentrations of a variety of biomarkers and of LMWA were previously determined and some analyses have been published by the MARK-AGE team. For the sake of simplicity, we assume that the concentration of an OS biomarker is a linear function of the concentration of a LMWA (if the association is due to causal relationship). A negative slope of this dependence (and sign of the correlation coefficient) can be intuitively expected for an antioxidant, a positive slope indicates that the LMWA is pro-oxidative, whereas extrapolation of the OS biomarker to [LMWA] = 0 is an approximation of the concentration of the OS biomarker in the absence of the LMWA. Using this strategy, we studied the effects of 12 LMWA (including tocopherols, carotenoids and ascorbic acid) on the OS status, as observed with 8 biomarkers of oxidative damage (including malondialdehyde, protein carbonyls, 3-nitrotyrosine). The results of this communication show that in a cross-sectional study the LMWA contribute little to the redox state and that different "antioxidants" are very different, so that single LMWA treatment of OS is not scientifically justified assuming our simple model. In view of the difficulty of quantitating the OS and the very different effects of various LMWA, the use of the "identify and treat" approach is questionable.

Dragon fruits are a valued source of bioactive compounds with high potential to become a functional food. The aim of the study was to evaluate and compare the chemopreventive potential and chemical composition of fruits harvested in Thailand and Israel. The amount of different compounds in water and methanol extracts and antioxidant activity was investigated. Moreover, cytotoxic activity against cancer and normal cells of skin, prostate, and gastrointestinal origin was performed, accompanied by anti-inflammatory assay based on NO production in RAW 264.7 macrophage model. Additionally, the quenching properties of polyphenols from fruits were determined by the interaction of the main drug carrier in blood human serum (HSA). The chemometric analysis was used to reveal the relationships between the determined parameters. Dragon fruits harvested in Israel revealed higher antioxidant properties and total content of polyphenols and betacyanins when compared to those from Thailand. The examined fruits of both origins showed significant cytotoxic activity toward colon and prostate cancer cells, with no toxic effect on normal cells, but also no anti-inflammatory effect. Moreover, a high binding ability to HSA was observed for water extracts of dragon fruits. All these predestine dragon fruits are the candidates for the attractive and chemopreventive elements of daily diet.

Dragon fruits are a valued source of bioactive compounds with high potential to become a functional food. The aim of the study was to evaluate and compare the chemopreventive potential and chemical composition of fruits harvested in Thailand and Israel. The amount of different compounds in water and methanol extracts and antioxidant activity was investigated. Moreover, cytotoxic activity against cancer and normal cells of skin, prostate, and gastrointestinal origin was performed, accompanied by anti-inflammatory assay based on NO production in RAW 264.7 macrophage model. Additionally, the quenching properties of polyphenols from fruits were determined by the interaction of the main drug carrier in blood human serum (HSA). The chemometric analysis was used to reveal the relationships between the determined parameters. Dragon fruits harvested in Israel revealed higher antioxidant properties and total content of polyphenols and betacyanins when compared to those from Thailand. The examined fruits of both origins showed significant cytotoxic activity toward colon and prostate cancer cells, with no toxic effect on normal cells, but also no anti-inflammatory effect. Moreover, a high binding ability to HSA was observed for water extracts of dragon fruits. All these predestine dragon fruits are the candidates for the attractive and chemopreventive elements of daily diet.

The human skin is a lush microbial habitat which is occupied by a wide array of microorganisms. Among the most common inhabitants are Staphylococcus spp., namely Staphylococcus epidermidis and, in ≈20% of healthy individuals, Staphylococcus aureus. Both bacteria have been associated with cutaneous maladies, where they mostly arrange in a biofilm, thus achieving improved surface adhesion and stability. Moreover, our skin is constantly exposed to numerous oxidative environmental stressors, such as UV-irradiation. Thus, skin cells are equipped with an important antioxidant defense mechanism, the Nrf2-Keap1 pathway. In this work, we aimed to explore the morphology of S. aureus and S. epidermidis as they adhered to healthy human skin and characterize their matrix composition. Furthermore, we hypothesized that the localization of both types of bacteria on a healthy skin surface may provide protective effects against oxidative stressors, such as UV-irradiation. Our results indicate for the first time that S. aureus and S. epidermidis assume a biofilm-like morphology as they adhere to ex vivo healthy human skin and that the cultures' extracellular matrix (ECM) is composed of extracellular polysaccharides (EPS) and extracellular DNA (eDNA). Both bacterial cultures, as well as isolated S. aureus biofilm eDNA, conferred cutaneous protection against UVB-induced apoptosis. This work emphasized the importance of skin microbiota representatives in the maintenance of a healthy cutaneous redox balance by activating the skin's natural defense mechanism.

Background: Stroke and thromboembolic events occurring among patients taking direct oral anticoagulants (DOACs) have been associated with low concentrations of DOACs. Enzyme-inducing antiseizure medications (EI-ASMs) are associated with enhanced cytochrome-P450-mediated metabolism and enhanced P-glycoprotein-mediated transport. Objective: The aim of this study was to evaluate the effect of concomitant EI-ASM use on DOAC peak concentrations in patients treated in clinical care. Methods: We performed a retrospective cohort study of patients treated with DOACs for atrial fibrillation and venous thromboembolic disease in an academic general hospital. In total, 307 patients treated with DOACs between August 2015 and January 2020 were reviewed. Clinical characteristics and peak DOAC plasma concentrations of patients co-treated with an EI-ASM were compared with those of patients not treated with an EI-ASM. An apixaban dose score (ADS) was defined to account for apixaban dosage and the number of apixaban dose-reduction criteria. Results: In total, 177 peak DOAC plasma concentrations (including apixaban, rivaroxaban, and dabigatran) from 131 patients were measured, including 24 patients co-treated with an EI-ASM and 107 controls not treated with an EI-ASM. The proportion of patients with DOAC concentrations below the expected range was significantly higher among EI-ASM users than among patients not taking an EI-ASM (37.5 vs. 9.3%, respectively; p = 0.0004; odds ratio 5.82; 95% confidence interval [CI] 2.03–16.66). Most of these patients were treated with apixaban (85%); however, sensitivity analysis results were also significant (p = 0.031) for patients with non-apixaban DOACs. In patients co-treated with apixaban and an EI-ASM, median apixaban peak concentration was 106 ng/mL (interquartile range [IQR] 71–181) compared with 150 ng/mL (IQR 94–222) in controls (p = 0.019). In multivariable analysis, EI-ASM use was associated with 6.26-fold increased odds for apixaban concentration below the expected range (95% CI 2.19–17.90; p = 0.001). Apixaban concentrations were significantly associated with EI-ASM use, moderate enzyme inhibitor use, and ADS. Conclusions: Concurrent EI-ASM and DOAC use presents a possible risk for DOAC concentrations below the expected range. The clinical significance of the interaction is currently unclear.

OBJECTIVE: Appropriate placental nutrient transfer is essential for optimal fetal development. We have previously shown that antiseizure medications (ASMs) can alter the expression of placental carriers for folate and thyroid hormones. Here we extended our analysis to heterodimeric carriers that mediate the placental uptake of amino acids and antioxidant precursors. We focused on the L-type amino acid transporter (LAT)2/SLC7A8, the cystine/glutamate antiporter xCT/SLC7A11, and their chaperone 4F2hc/SLC3A2. METHODS: BeWo cells were exposed for two or five days to therapeutic concentrations of valproate, levetiracetam, carbamazepine, lamotrigine, or lacosamide. Transcript levels were measured by quantitative PCR. Levetiracetam effects on placental carriers were further explored using a tailored gene array. RESULTS: At five days, 30 $μ$g/mL levetiracetam (high therapeutic concentrations) significantly reduced the expression of all studied genes (p < 0.05). Carbamazepine treatment was associated with lower SLC7A8 (LAT2) expression (p < 0.05), whereas valproate increased the transcript levels of this transporter by up to 2.0-fold (p < 0.01). Some of these effects were already observed after two incubation days. Lamotrigine did not alter gene expression, and lacosamide slightly elevated SLC3A2 levels (p < 0.05). The array analysis confirmed the trends observed for levetiracetam and identified additional affected genes. SIGNIFICANCE: Altered expression of placental heterodimeric transporters may represent a mechanism by which ASM affect fetal development. The placental effects are differential, with valproate, carbamazepine and levetiracetam as the more active compounds. The concentration-dependence of those ASM effects are in line with established dose-dependent teratogenicity implying that ASM doses should be adjusted during pregnancy with caution.

Despite the increased use of medical cannabinoids, the efficacy and safety of the treatment among children remain uncertain. The objective was to study the efficacy and safety of medical cannabinoids in children. The search included studies through 11-May-2020. Selection criteria included studies evaluating efficacy and safety outcomes of medical cannabinoids (tetrahydrocannabinol, cannabidiol and other cannabis derivatives) versus control in children, independently assessed by two reviewers. Eight studies were included, all of which are randomized controlled trials. Cannabidiol is associated with 50% reduction in seizures rate (Relative Risk (RR) = 1.69, 95% CI [1.20-2.36]) and caregiver global impression of change (Median Estimated difference = (- 1), 95%CI [- 1.39-(- 0.60)]) in Dravet syndrome, compared to placebo. While cannabidiol was associated with a reduction in reported seizure events (RR = 0.59, 95% CI [0.36-0.97]), no association was found in products contained also tetrahydrocannabinol (RR = 1.35, 95% CI [0.46-4.03]). Higher dose of cannabidiol was associated with decreased appetite (RR = 2.40, 95% CI [1.39-4.15]). A qualitative assessment suggests that medical cannabinoids might be associated with adverse mental events. In conclusion, cannabidiol is associated with clinical improvement in Dravet syndrome. However, cannabidiol is also associated with decreased appetite. Adverse mental events were reported as well, however, more research should be performed to assess well this outcome.

BACKGROUND: Inflammatory bowel diseases (IBDs) are chronic, idiopathic, inflammatory, gastrointestinal disorders. The endocannabinoid system may have a role in the pathogenesis of IBD. We aimed to assess whether cannabis treatment influences endocannabinoids (eCBs) level and clinical symptoms of IBD patients. METHODS: Blood samples and biopsies were taken from IBD patients treated by either cannabis or placebo for 8 weeks. Immunohistochemistry for N-acyl-phosphatidylethanolamine-selective phospholipase D (NAPE-PLD) and fatty acid amide hydrolase (FAAH) expression was done on colon biopsies, and sample levels of anandamide (AEA), eCB2-arachidonylglycerol (2-AG), arachidonic acid (AA), palmitoylethanolamine (PEA), and oleoylethanolamine (OEA) were measured in patient's sera before and after cannabis treatment. Caco-2 cells were cultured with extracts of cannabis with/without tetrahydrocannabinol (THC) and their proteins extracted, and Western blotting for NAPE-PLD and FAAH expression was done. RESULTS: Thirteen patients with Crohn's disease (CD) and nine patients with ulcerative colitis (UC) were treated with cannabis. Seventeen patients with CD and 10 with UC served as placebo groups. In all CD patients, the levels of eCBs remained unaltered during the treatment period. In UC patients treated with placebo, but not in those treated with cannabis, the levels of PEA, AEA, and AA decreased significantly. The percent reduction in bowel movements was negatively correlated with changes observed in the circulating AEA and OEA, whereas improvement in quality of life was positively correlated with the levels of 2-AG. In the biopsies from UC patients, FAAH levels increased over the study period. In Caco-2 cells, both cannabis extracts increased NAPE-PLD levels but reduced FAAH expression levels. CONCLUSION: Our study supports the notion that cannabis use affects eCB "tone" in UC patients and may have beneficial effects on disease symptoms in UC patients.

Insulin secretion from pancreatic beta cells is tightly regulated by glucose and paracrine signals within the microenvironment of islets of Langerhans. Extracellular matrix from islet microcapillary endothelial cells (IMEC) affect beta-cell spreading and amplify insulin secretion. This study was aimed at investigating the hypothesis that contact-independent paracrine signals generated from IMEC may also modulate beta-cell insulin secretory functions. For this purpose, conditioned medium (CMp) preparations were prepared from primary cultures of rat IMEC and were used to simulate contact-independent beta cell-endothelial cell communication. Glucose-stimulated insulin secretion (GSIS) assays were then performed on freshly isolated rat islets and the INS-1E insulinoma cell line, followed by fractionation of the CMp, mass spectroscopic identification of the factor, and characterization of the mechanism of action. The IMEC-derived CMp markedly attenuated first-and second-phase GSIS in a time-and dose-dependent manner without altering cellular insulin content and cell viability. Size exclusion fractionation, chromatographic and mass-spectroscopic analyses of the CMp identified the attenuating factor as the enzyme triosephosphate isomerase (TPI). An antibody against TPI abrogated the attenuating activity of the CMp while recombinant human TPI (hTPI) attenuated GSIS from beta cells. This effect was reversed in the presence of tolbutamide in the GSIS assay. In silico docking simulation identified regions on the TPI dimer that were important for potential interactions with the extracellular epitopes of the sulfonylurea receptor in the complex. This study supports the hypothesis that an effective paracrine interaction exists between IMEC and beta cells and modulates glucose-induced insulin secretion via TPI-sulfonylurea receptor-KATP channel (SUR1-Kir6.2) complex attenuating interactions.

Uptake of particles by cells involves various natural mechanisms that are essential for their biological functions. The same mechanisms are used in the engulfment of synthetic colloidal drug carriers, while the extent of the uptake affects the biological performance and selectivity. Thus far, little is known regarding the effect of external biomechanical stimuli on the capacity of the cells to uptake nano and micro carriers. This is relevant for anchorage-dependent cells that have detached from surfaces or for cells that travel in the body such as tumor cells, immune cells and various circulating stem cells. In this study, we hypothesize that cellular deformability is a crucial physical effector for the successful execution of the phagocytosis-like uptake in cancer cells. To test this assumption, we develop a well-controlled tunable method to compare the uptake of inert particles by cancer cells in adherent and non-adherent conditions. We introduce a self-designed 3D-printed apparatus, which enables constant stirring while facilitating a floating environment for cell incubation. We reveal a mechanically mediated phagocytosis-like behavior in various cancer cells, that was dramatically enhance in the detached cell state. Our findings emphasize the importance of including proper biomechanical cues to reliably mimic certain physiological scenarios. Beyond that, we offer a cost-effective accessible research tool to study mixed cultures for both adherent and non-adherent cells.

In 2020, racemic-fenfluramine was approved in the U.S. and Europe for the treatment of seizures associated with Dravet syndrome, through a restricted/controlled access program aimed at minimizing safety risks. Fenfluramine had been used extensively in the past as an appetite suppressant, but it was withdrawn from the market in 1997 when it was found to cause cardiac valvulopathy. Available evidence indicates that appetite suppression and cardiac valvulopathy are mediated by different serotonergic mechanisms. In particular, appetite suppression can be ascribed mainly to the enantiomers d-fenfluramine and d-norfenfluramine, the primary metabolite of d-fenfluramine, whereas cardiac valvulopathy can be ascribed mainly to d-norfenfluramine. Because of early observations of markedly improved seizure control in some forms of epilepsy, fenfluramine remained available in Belgium through a Royal Decree after 1997 for use in a clinical trial in patients with Dravet syndrome at average dosages lower than those generally prescribed for appetite suppression. More recently, double-blind placebo-controlled trials established its efficacy in the treatment of convulsive seizures associated with Dravet syndrome and of drop seizures associated with Lennox-Gastaut syndrome, at doses up to 0.7 mg/kg/day (maximum 26 mg/day). Although no cardiovascular toxicity has been associated with the use of fenfluramine in epilepsy, the number of patients exposed to date has been limited and only few patients had duration of exposure longer than 3 years. This article analyzes available evidence on the mechanisms involved in fenfluramine-induced appetite suppression, antiseizure effects and cardiovascular toxicity. Despite evidence that stimulation of 5-HT(2B) receptors (the main mechanism leading to cardiac valvulopathy) is not required for antiseizure activity, there are many critical gaps in understanding fenfluramine's properties which are relevant to its use in epilepsy. Particular emphasis is placed on the remarkable lack of publicly accessible information about the comparative activity of the individual enantiomers of fenfluramine and norfenfluramine in experimental models of seizures and epilepsy, and on receptors systems considered to be involved in antiseizure effects. Preliminary data suggest that l-fenfluramine retains prominent antiseizure effects in a genetic zebrafish model of Dravet syndrome. If these findings are confirmed and extended to other seizure/epilepsy models, there would be an incentive for a chiral switch from racemic-fenfluramine to l-fenfluramine, which could minimize the risk of cardiovascular toxicity and reduce the incidence of adverse effects such as loss of appetite and weight loss.

BACKGROUND: Nearly a year into the COVID-19 pandemic, we still lack effective anti-SARS-CoV-2 drugs with substantial impact on mortality rates except for dexamethasone. As the search for effective antiviral agents continues, we aimed to review data on the potential of repurposing antiparasitic drugs against viruses in general, with an emphasis on coronaviruses. METHODS: We performed a review by screening in vitro and in vivo studies that assessed the antiviral activity of several antiparasitic agents: chloroquine, hydroxychloroquine (HCQ), mefloquine, artemisinins, ivermectin, nitazoxanide (NTZ), niclosamide, atovaquone and albendazole. RESULTS: For HCQ and chloroquine we found ample in vitro evidence of antiviral activity. Cohort studies that assessed the use of HCQ for COVID-19 reported conflicting results, but randomized controlled trials (RCTs) demonstrated no effect on mortality rates and no substantial clinical benefits of HCQ used either for prevention or treatment of COVID-19. We found two clinical studies of artemisinins and two studies of NTZ for treatment of viruses other than COVID-19, all of which showed mixed results. Ivermectin was evaluated in one RCT and few observational studies, demonstrating conflicting results. As the level of evidence of these data is low, the efficacy of ivermectin against COVID-19 remains to be proven. For chloroquine, HCQ, mefloquine, artemisinins, ivermectin, NTZ and niclosamide, we found in vitro studies showing some effects against a wide array of viruses. We found no relevant studies for atovaquone and albendazole. CONCLUSIONS: As the search for an effective drug active against SARS-CoV-2 continues, we argue that pre-clinical research of possible antiviral effects of compounds that could have antiviral activity should be conducted. Clinical studies should be conducted when sufficient in vitro evidence exists, and drugs should be introduced into widespread clinical use only after being rigorously tested in RCTs. Such a search may prove beneficial in this pandemic or in outbreaks yet to come.