Pharmacokinetics of Edaravone Oral Suspension in Patients With Amyotrophic Lateral Sclerosis.

PURPOSE: Edaravone is a neuroprotective agent approved as an intravenous treatment for amyotrophic lateral sclerosis (ALS). The intravenous administration of edaravone places a burden on patients and there is a clinical need for oral agents for the treatment of ALS. This report aimed to assess the pharmacokinetics and safety of an edaravone oral suspension in patients with ALS after oral and percutaneous endoscopic gastrostomy (PEG) tube administration. METHODS: Two single-dose, open-label phase 1 clinical studies were conducted. Edaravone oral suspension (105 mg of edaravone in 5 mL aqueous suspension) was administered orally and via PEG tube to 9 and 6 Japanese patients with ALS, respectively. Plasma and urinary pharmacokinetics of unchanged edaravone and its metabolites (sulfate and glucuronide conjugates) were determined. Safety was also evaluated. FINDINGS: After reaching maximum plasma concentration, the mean plasma concentration-time of unchanged edaravone showed a triphasic elimination. Mean plasma concentration-time profiles of the metabolites were higher than those of unchanged edaravone. The mean urinary excretion ratios were higher for the glucuronide conjugate than for either unchanged edaravone or the sulfate conjugate. In patients administered edaravone orally, a single adverse event occurred (blood urine present), which was mild and improved without medical intervention. No adverse drug reactions or serious adverse events were reported. In patients administered edaravone via PEG tube, 5 treatment-emergent adverse events were reported in 3 patients; none were related to the study drug. No adverse drug reactions were reported. IMPLICATIONS: In patients with ALS, a single dose of edaravone oral suspension was well absorbed and mainly eliminated in urine as the glucuronide conjugate. No safety concerns emerged. Pharmacokinetics were similar to those previously reported in healthy participants following oral administration. This indicates that effective drug concentrations were achieved and edaravone can be successfully administered both orally and via a PEG tube in patients with ALS. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov, NCT04176224 (oral administration) and NCT04254913 (PEG tube administration), www. CLINICALTRIALS: gov.

Riluzole in Spinal Cord Injury Study (RISCIS)-Pharmacokinetic (PK) Sub-Study: An Analysis of Pharmacokinetics, Pharmacodynamics, and Impact on Axonal Degradation of Riluzole in Patients With Traumatic Cervical Spinal Cord Injury Enrolled in the RISCIS Phase III Randomized Controlled Trial.

To date, no drug therapy has shown significant efficacy in improving functional outcomes in patients with acute spinal cord injury (SCI). Riluzole is an approved benzothiazole sodium channel blocker to attenuate neurodegeneration in amyotrophic lateral sclerosis (ALS) and is of interest for neuroprotection in SCI. In a Phase I clinical trial (ClinicalTrials.gov Identifier: NCT00876889), riluzole was well tolerated with a 2-week treatment at the dose level approved for ALS and exhibited potential efficacy in patients with SCI. The acute and progressive nature of traumatic SCI and the complexity of secondary injury processes alter the pharmacokinetics (PK) of therapeutics. In the PK sub-study of the multi-center, randomized, placebo-controlled, double-blinded Riluzole in Spinal Cord Injury Study (RISCIS) Phase II/III trial (ClinicalTrials.gov Identifier: NCT01597518), a total of 32 SCI patients were enrolled, and most of our patients were middle-age Caucasian males with head and neck injuries. We studied the PK and pharmacodynamics (PD) of riluzole on motor recovery, measured by International Standards for Neurological Classification of SCI (ISNCSCI) Motor Score at injury and at 3-month and 6-month follow-ups, along with levels of the axonal injury biomarker phosphorylated neurofilament heavy chain (pNF-H), during the 2-week treatment. PK modeling, PK/PD correlations were developed to identify the potential effective exposure of riluzole for intended PD outcomes. The longitudinal impacts of SCI on the PK of riluzole are characterized. A time-varying population PK model of riluzole is established, incorporating time-varying clearance and volume of distribution from combined data of Phase I and Phase II/III trials. With the developed model, a rational, optimal dosing scheme can be designed with time-dependent modification to preserve the required therapeutic exposure of riluzole. The PD of riluzole and the relationship between PK and neurological outcomes of the treatment were established. The time course of efficacy in total motor score improvement (ΔTMS) and pNF-H were monitored. A three-dimensional (3D) PK/PD correlation was established for ΔTMS at 6 months with overall riluzole exposure area under the curve for Day 0-Day14 (AUCD0-D14) and baseline TMS for individual patients. Patients with baseline TMS between 1 and 36 benefited from the optimal exposure range of 16-48 mg*h/mL. The PD models of pNF-H revealed the riluzole efficacy, as treated subjects exhibited a diminished increase in progression of pNF-H, indicative of reduced axonal breakdown. The independent parameter of area between effective curves (ABEC) between the time profiles of pNF-H in placebo and treatment groups was statistically identified as a significant predictor for the treatment effect on the biomarker. A mechanistic clinical outcomes (CO)/PD (pNF-H) model was established, and the proposed structure demonstrated the feasibility of PK/PD/CO correlation model. No appreciable hepatic toxicity was observed with the current riluzole treatment regimen. The development of effective treatment for SCI is challenging. However, the future model-informed and PK-guided drug development and regimen modification can be rationally executed with the optimal dosing regimen design based on the developed 3D PK/PD model. The PK/PD/CO model can serve as a rational guide for future drug development, PKPD model refinement, and extension to other studies in SCI settings.

Concise Overview of Glypromate Neuropeptide Research: From Chemistry to Pharmacological Applications in Neurosciences.

Neurodegenerative diseases of the central nervous system (CNS) pose a serious health concern worldwide, with a particular incidence in developed countries as a result of life expectancy increase and the absence of restorative treatments. Presently, treatments for these neurological conditions are focused on managing the symptoms and/or slowing down their progression. As so, the research on novel neuroprotective drugs is of high interest. Glypromate (glycyl-l-prolyl-l-glutamic acid, also known as GPE), an endogenous small peptide widespread in the brain, holds great promise to tackle neurodegenerative diseases such as Parkinson's, Alzheimer's, and Huntington's, s well as other CNS-related disorders like Rett and Down's syndromes. However, the limited pharmacokinetic properties of Glypromate hinder its clinical application. As such, intense research has been devoted to leveraging the pharmacokinetic profile of this neuropeptide. This review aims to offer an updated perspective on Glypromate research by exploring the vast array of chemical derivatizations of more than 100 analogs described in the literature over the past two decades. The collection and discussion of the most relevant structure-activity relationships will hopefully guide the discovery of new Glypromate-based neuroprotective drugs.

Macrophage membrane modified baicalin liposomes improve brain targeting for alleviating cerebral ischemia reperfusion injury.

Baicalin (BA) has a good intervention effect on encephalopathy. In this study, macrophage membrane was modified on the surface of baicalin liposomes (BA-LP) by extrusion method. Macrophage membrane modified BA-LP (MM-BA-LP) was characterized by various analytical techniques, and evaluated for brain targeting. The results presented MM-BA-LP had better brain targeting compared with BA-LP. Pharmacokinetic experiments showed that MM-BA-LP improved pharmacokinetic parameters and increased the residence time of BA. Pharmacodynamic of middle cerebral artery occlusion (MCAO) rat model was studied to verify the therapeutic effect of MM-BA-LP on cerebral ischemia reperfusion injury (CIRI). The results showed that MM-BA-LP could significantly improve the neurological deficit, cerebral infarction volume and brain pathological state of MCAO rats compared with BA-LP. These results suggested that MM-BA-LP could significantly enhance the brain targeting and improve the circulation of BA in blood, and had a significantly better neuroprotective effect on MCAO rats than BA-LP.

Blood-Brain Barrier Transporters: Opportunities for Therapeutic Development in Ischemic Stroke.

Globally, stroke is a leading cause of death and long-term disability. Over the past decades, several efforts have attempted to discover new drugs or repurpose existing therapeutics to promote post-stroke neurological recovery. Preclinical stroke studies have reported successes in identifying novel neuroprotective agents; however, none of these compounds have advanced beyond a phase III clinical trial. One reason for these failures is the lack of consideration of blood-brain barrier (BBB) transport mechanisms that can enable these drugs to achieve efficacious concentrations in ischemic brain tissue. Despite the knowledge that drugs with neuroprotective properties (i.e., statins, memantine, metformin) are substrates for endogenous BBB transporters, preclinical stroke research has not extensively studied the role of transporters in central nervous system (CNS) drug delivery. Here, we review current knowledge on specific BBB uptake transporters (i.e., organic anion transporting polypeptides (OATPs in humans; Oatps in rodents); organic cation transporters (OCTs in humans; Octs in rodents) that can be targeted for improved neuroprotective drug delivery. Additionally, we provide state-of-the-art perspectives on how transporter pharmacology can be integrated into preclinical stroke research. Specifically, we discuss the utility of in vivo stroke models to transporter studies and considerations (i.e., species selection, co-morbid conditions) that will optimize the translational success of stroke pharmacotherapeutic experiments.

The Therapeutic Effect of Acanthopanax senticosus Components on Radiation-Induced Brain Injury Based on the Pharmacokinetics and Neurotransmitters.

Acanthopanax senticosus (AS) is a medicinal and food homologous plant with many biological activities. In this research, we generated a brain injury model by 60Co -γ ray radiation at 4 Gy, and gavaged adult mice with the extract with AS, Acanthopanax senticocus polysaccharides (ASPS), flavones, syringin and eleutheroside E (EE) to explore the therapeutic effect and metabolic characteristics of AS on the brain injury. Behavioral tests and pathological experiments showed that the AS prevented the irradiated mice from learning and memory ability impairment and protected the neurons of irradiated mice. Meanwhile, the functional components of AS increased the antioxidant activity of irradiated mice. Furthermore, we found the changes of neurotransmitters, especially in the EE and syringin groups. Finally, distribution and pharmacokinetic analysis of AS showed that the functional components, especially EE, could exert their therapeutic effects in brain of irradiated mice. This lays a theoretical foundation for the further research on the treatment of radiation-induced brain injury by AS.

Discovery of G2019S-Selective Leucine Rich Repeat Protein Kinase 2 inhibitors with in vivo efficacy.

Mutations in the Leucine Rich Repeat Protein Kinase 2 gene (LRRK2) are the most common genetic causes of Parkinson's Disease (PD). The G2019S mutation is the most common inherited LRRK2 mutation, occurs in the kinase domain, and results in increased kinase activity. We report the discovery and development of compound 38, an indazole-based, G2019S-selective (>2000-fold vs. WT) LRRK2 inhibitor capable of entering rodent brain (Kp = 0.5) and selectively inhibiting G2019S-LRRK2. The compounds disclosed herein present a starting point for further development of brain penetrant G2019S selective inhibitors that hopefully reduce lung phenotype side-effects and pave the way to providing a precision medicine for people with PD who carry the G2019S mutation.

Combination therapy for cerebral ischemia: do progesterone and noscapine provide better neuroprotection than either alone in the treatment?

Ischemic stroke presents multifaceted pathological outcomes with overlapping mechanisms of cerebral injury. High mortality and disability with stroke warrant a novel multi-targeted therapeutic approach. The neuroprotection with progesterone (PG) and noscapine (NOS) on cerebral ischemia-reperfusion (I-R) injury was demonstrated individually, but the outcome of combination treatment to alleviate cerebral damage is still unexplored. Randomly divided groups of rats (n = 6) were Sham-operated, I-R, PG (8 mg/kg), NOS (10 mg/kg), and PG + NOS (8 mg/kg + 10 mg/kg). The rats were exposed to bilateral common carotid artery occlusion, except Sham-operated, to investigate the therapeutic outcome of PG and NOS alone and in combination on I-R injury. Besides the alterations in cognitive and motor abilities, we estimated infarct area, oxidative stress, blood-brain barrier (BBB) permeability, and histology after treatment. Pharmacokinetic parameters like Cmax, Tmax, half-life, and AUC0-t were estimated in biological samples to substantiate the therapeutic outcomes of the combination treatment. We report PG and NOS prevent loss of motor ability and improve spatial memory after cerebral I-R injury. Combination treatment significantly reduced inflammation and restricted infarction; it attenuated oxidative stress and BBB damage and improved grip strength. Histopathological analysis demonstrated a significant reduction in leukocyte infiltration with the most profound effect in the combination group. Simultaneous analysis of PG and NOS in plasma revealed enhanced peak drug concentration, improved AUC, and prolonged half-life; the drug levels in the brain have increased significantly for both. We conclude that PG and NOS have beneficial effects against brain damage and the co-administration further reinforced neuroprotection in the cerebral ischemia-reperfusion injury.

Post-Ischemic Brain Neurodegeneration in the Form of Alzheimer's Disease Proteinopathy: Possible Therapeutic Role of Curcumin.

For thousands of years, mankind has been using plant extracts or plants themselves as medicinal herbs. Currently, there is a great deal of public interest in naturally occurring medicinal substances that are virtually non-toxic, readily available, and have an impact on well-being and health. It has been noted that dietary curcumin is one of the regulators that may positively influence changes in the brain after ischemia. Curcumin is a natural polyphenolic compound with pleiotropic biological properties. The observed death of pyramidal neurons in the CA1 region of the hippocampus and its atrophy are considered to be typical changes for post-ischemic brain neurodegeneration and for Alzheimer's disease. Additionally, it has been shown that one of the potential mechanisms of severe neuronal death is the accumulation of neurotoxic amyloid and dysfunctional tau protein after cerebral ischemia. Post-ischemic studies of human and animal brains have shown the presence of amyloid plaques and neurofibrillary tangles. The significant therapeutic feature of curcumin is that it can affect the aging-related cellular proteins, i.e., amyloid and tau protein, preventing their aggregation and insolubility after ischemia. Curcumin also decreases the neurotoxicity of amyloid and tau protein by affecting their structure. Studies in animal models of cerebral ischemia have shown that curcumin reduces infarct volume, brain edema, blood-brain barrier permeability, apoptosis, neuroinflammation, glutamate neurotoxicity, inhibits autophagy and oxidative stress, and improves neurological and behavioral deficits. The available data suggest that curcumin may be a new therapeutic substance in both regenerative medicine and the treatment of neurodegenerative disorders such as post-ischemic neurodegeneration.

Preclinical investigation of Pegylated arginase 1 as a treatment for retina and brain injury.

Arginase 1 (A1) is the enzyme that hydrolyzes the amino acid, L-arginine, to ornithine and urea. We have previously shown that A1 deletion worsens retinal ischemic injury, suggesting a protective role of A1. In this translational study, we aimed to study the utility of systemic pegylated A1 (PEG-A1, recombinant human arginase linked to polyethylene glycol) treatment in mouse models of acute retinal and brain injury. Cohorts of WT mice were subjected to retinal ischemia-reperfusion (IR) injury, traumatic optic neuropathy (TON) or brain cerebral ischemia via middle cerebral artery occlusion (MCAO) and treated with intraperitoneal injections of PEG-A1 or vehicle (PEG only). Drug penetration into retina and brain tissues was measured by western blotting and immunolabeling for PEG. Neuroprotection was measured in a blinded fashion by quantitation of NeuN (neuronal marker) immunolabeling of retina flat-mounts and brain infarct area using triphenyl tetrazolium chloride (TTC) staining. Furthermore, ex vivo retina explants and in vitro retina neuron cultures were subjected to oxygen-glucose deprivation (OGD) followed by reoxygenation (R) and treated with PEG-A1. PEG-A1 given systemically did not cross the intact blood-retina/brain barriers in sham controls but reached the retina and brain after injury. PEG-A1 provided neuroprotection after retinal IR injury, TON and cerebral ischemia. PEG-A1 treatment was also neuroprotective in retina explants subjected to OGD/R but did not improve survival in retinal neuronal cultures exposed to OGD/R. In summary, systemic PEG-A1 administration is neuroprotective and provides an excellent route to deliver the drug to the retina and the brain after acute injury.

Curcumin for parkinson´s disease: potential therapeutic effects, molecular mechanisms, and nanoformulations to enhance its efficacy.

Parkinson's disease (PD) is one of the most prevalent neurodegenerative disorders worldwide. It is caused by the degeneration of dopaminergic neurons from the substantia nigra pars compacta. This neuronal loss causes the dopamine deficiency that leads to a series of functional changes within the basal ganglia, producing motor control abnormalities. L-DOPA is considered the gold standard for PD treatment, and it may alleviate its clinical manifestations for some time. However, its prolonged administration produces tolerance and several severe side effects, including dyskinesias and gastrointestinal disorders. Thus, there is an urgent need to find effective medications, and current trends have proposed some natural products as emerging options for this purpose. Concerning this, curcumin represents a promising bioactive compound with high therapeutic potential. Diverse studies in cellular and animal models have suggested that curcumin could be employed for the treatment of PD. Therefore, the objective of this narrative mini-review is to present an overview of the possible therapeutic effects of curcumin and the subjacent molecular mechanisms. Moreover, we describe several possible nanocarrier-based approaches to improve the bioavailability of curcumin and enhance its biological activity.

Phytosterols: Potential Metabolic Modulators in Neurodegenerative Diseases.

Phytosterols constitute a class of natural products that are an important component of diet and have vast applications in foods, cosmetics, and herbal medicines. With many and diverse isolated structures in nature, they exhibit a broad range of biological and pharmacological activities. Among over 200 types of phytosterols, stigmasterol and ß-sitosterol were ubiquitous in many plant species, exhibiting important aspects of activities related to neurodegenerative diseases. Hence, this mini-review presented an overview of the reported studies on selected phytosterols related to neurodegenerative diseases. It covered the major phytosterols based on biosynthetic considerations, including other phytosterols with significant in vitro and in vivo biological activities.

Rapid and improved oral absorption of N-butylphthalide by sodium cholate-appended liposomes for efficient ischemic stroke therapy.

As a multi-target drug to treat ischemic stroke, N-butylphthalide (NBP) is extremely water-insoluble and exhibits limited oral bioavailability, impeding its wide oral application. Effective treatment of ischemic stroke by NBP requires timely and efficient drug exposure, necessitating the development of new oral formulations. Herein, liposomes containing biosurfactant sodium cholate (CA-liposomes) were systemically investigated as an oral NBP delivery platform because of its high biocompatibility and great potential for clinical applications. The optimized liposomes have a uniform hydrodynamic size of 104.30 ± 1.60 nm and excellent encapsulation efficiency (93.91 ± 1.10%). Intriguingly, NBP-loaded CA-liposomes produced rapid drug release and the cumulative release was up to 88.09 ± 4.04% during 12 h while that for NBP group was only 6.79 ± 0.99%. Caco-2 cell monolayer assay demonstrated the superior cell uptake and transport efficiency of NBP-loaded CA-liposomes than free NBP, which was mediated by passive diffusion via transcellular and paracellular routes. After oral administration to rats, NBP-loaded CA-liposomes exhibited rapid and almost complete drug absorption, with a tmax of 0.70 ± 0.14 h and an absolute bioavailability of 92.65% while NBP suspension demonstrated relatively low bioavailability (21.7%). Meanwhile, NBP-loaded CA-liposomes produced 18.30-fold drug concentration in the brain at 5 min compared with NBP suspension, and the brain bioavailability increased by 2.48-fold. As expected, NBP-loaded CA-liposomes demonstrated significant therapeutic efficacy in a middle cerebral artery occlusion rat model. Our study provides new insights for engineering oral formulations of NBP with fast and sufficient drug exposure against ischemic stroke in the clinic.

Neuroprotective effects of macamide from maca (Lepidium meyenii Walp.) on corticosterone-induced hippocampal impairments through its anti-inflammatory, neurotrophic, and synaptic protection properties.

The present study aims to investigate the protective effects of N-(3-methoxybenzyl)-(9Z,12Z,15Z)-octadecatrienamide (M 18:3) on corticosterone-induced neurotoxicity. A neurotoxic model was established by subcutaneous injection of corticosterone (40 mg per kg bw) for 21 days. Depressive behaviors (the percentage of sucrose consumption, the immobility time in the forced swimming test, and the total distance in the open field test) were observed. The levels of the brain-derived neurotrophic factor, the contents of tumor necrosis factor-α and interleukin-6, and the numbers of positive cells of doublecortin and bromodeoxyuridine in the hippocampus were measured. The density of hippocampal neurons was calculated. The morphological changes of hippocampal neurons (the density of dendritic spines, the dendritic length, and the area and volume of dendritic cell bodies) were observed. The expression levels of synaptophysin, synapsin I, and postsynaptic density protein 95 were measured. Behavioral experiments showed that M 18:3 (5 and 25 mg per kg bw) could remarkably improve the depressive behaviors. The enzyme-linked immunosorbent assay showed that M 18:3 could considerably reduce hippocampal neuroinflammation and increase hippocampal neurotrophy. Nissl staining showed that M 18:3 could remarkably improve the corticosterone-induced decrease in the hippocampal neuron density. Immunofluorescence analysis showed that M 18:3 could considerably promote hippocampal neurogenesis. Golgi staining showed that M 18:3 could remarkably improve the corticosterone-induced changes in the hippocampal dendritic structure. Western blotting showed that M 18:3 could considerably increase the expression levels of synaptic-structure-related proteins in the hippocampus. In conclusion, the protective effects of M 18:3 may be attributed to the anti-inflammatory, neurotrophic, and synaptic protection properties.

Neuroprotective effects of curcumin-loaded nanophytosome on ketamine-induced schizophrenia-like behaviors and oxidative damage in male mice.

Curcumin as an antioxidant natural herb has shown numerous pharmacological effects. However, the poor bioavailability of curcumin is a significant pharmacological barrier for its antioxidant activities. The present study was conducted to develop curcumin-loaded nanophytosome (CNP) and explore their therapeutic potential in a ketamine (KET)-induced schizophrenia (SCZ) model. The mice in our experiment were treated orally with curcumin and CNP (20 mg/kg) for 30 consecutive days. In addition, the animals received intraperitoneal injection of KET (30 mg/kg/day) from the 16th to the 30th day. SCZ-like behaviors were evaluated employing forced swimming test (FST), open field test (OFT), and novel object recognition test (NORT), and oxidative stress markers in the brain were estimated. Our results revealed that CNP has a greater neuroprotective effect compared to free curcumin. CNP pretreatment significantly ameliorated KET-induced brain injury evidenced by a marked reduction in the depressive and anxiety-like behaviors, memory deficits, and oxidative stress markers in cortical and subcortical tissues. Therefore, CNP, as a suitable drug delivery system, may improve curcumin bioavailability and confer stronger neuroprotective effects against KET-induced behavioral deficits and oxidative damages.

Effects of the sigma-1 receptor agonist blarcamesine in a murine model of fragile X syndrome: neurobehavioral phenotypes and receptor occupancy.

Fragile X syndrome (FXS), a disorder of synaptic development and function, is the most prevalent genetic form of intellectual disability and autism spectrum disorder. FXS mouse models display clinically-relevant phenotypes, such as increased anxiety and hyperactivity. Despite their availability, so far advances in drug development have not yielded new treatments. Therefore, testing novel drugs that can ameliorate FXS' cognitive and behavioral impairments is imperative. ANAVEX2-73 (blarcamesine) is a sigma-1 receptor (S1R) agonist with a strong safety record and preliminary efficacy evidence in patients with Alzheimer's disease and Rett syndrome, other synaptic neurodegenerative and neurodevelopmental disorders. S1R's role in calcium homeostasis and mitochondrial function, cellular functions related to synaptic function, makes blarcamesine a potential drug candidate for FXS. Administration of blarcamesine in 2-month-old FXS and wild type mice for 2 weeks led to normalization in two key neurobehavioral phenotypes: open field test (hyperactivity) and contextual fear conditioning (associative learning). Furthermore, there was improvement in marble-burying (anxiety, perseverative behavior). It also restored levels of BDNF, a converging point of many synaptic regulators, in the hippocampus. Positron emission tomography (PET) and ex vivo autoradiographic studies, using the highly selective S1R PET ligand [18F]FTC-146, demonstrated the drug's dose-dependent receptor occupancy. Subsequent analyses also showed a wide but variable brain regional distribution of S1Rs, which was preserved in FXS mice. Altogether, these neurobehavioral, biochemical, and imaging data demonstrates doses that yield measurable receptor occupancy are effective for improving the synaptic and behavioral phenotype in FXS mice. The present findings support the viability of S1R as a therapeutic target in FXS, and the clinical potential of blarcamesine in FXS and other neurodevelopmental disorders.

Sex differences in the cerebroprotection by Nestorone intranasal delivery following stroke in mice.

Our previous studies showed that intranasal delivery of progesterone offers a good bioavailability and neuroprotective efficacy after experimental stroke. We have also demonstrated that progesterone receptors (PR) are essential for cerebroprotection by endogenous progesterone and by progesterone treatment. The identification of PR as a potential drug target for stroke therapy opens new therapeutic indications for selective synthetic progestins. Nestorone® (16-methylene-17α-acetoxy-19-nor-pregn-4-ene-3, 20-dione, also known as segesterone acetate) is a 19-norprogesterone derivative that more potently targets PR than progesterone. The objective of this study was to evaluate the cerebroprotective efficiency of intranasal administration of Nestorone after middle cerebral occlusion (MCAO) in mice. We show here that intranasal administration is a very efficient route to achieve a preferential delivery of Nestorone to the brain and confers a slow elimination and a sustained bioavailability. Furthermore, intranasal administration of Nestorone (at 0.08 mg/kg) improved the functional outcomes and decreased the ischemic lesion in male but not in female mice at 48 h post MCAO. Use of PRNesCre mice, selectively lacking expression of PR in neural cells, and their control PRloxP/loxP littermates showed that the cerebroprotective effects of Nestorone in male mice depended on neural PR as they were not observed in PRNesCre mice. Our findings show that intranasal delivery of Nestorone may be an efficient strategy to promote recovery after stroke in males and confirm the key role of PR in cerebroprotection. Furthermore, they point to sex differences in the response to Nestorone treatment and emphasize the necessity to include males and females in experimental studies.

Targeting both BDNF/TrkB pathway and delta-secretase for treating Alzheimer's disease.

Alzheimer's disease (AD) is the most common dementia, and no disease-modifying therapeutic agents are currently available. BDNF/TrkB signaling is impaired in AD and is associated with prominent delta-secretase (δ-secretase, also known as asparaginyl endopeptidase or legumain) activation, which simultaneously cleaves both APP and Tau and promotes Aß production and neurofibrillary tangles (NFT) pathologies. Here we show that the optimized δ-secretase inhibitor (#11a) or TrkB receptor agonist (CF3CN) robustly blocks δ-secretase activity separately, and their combination synergistically blunts δ-secretase, exhibiting promising therapeutic efficacy in 3xTg AD mouse model. The optimal δ-secretase inhibitor reveals demonstrable brain exposure and oral bioavailability, suppressing APP N585 and Tau N368 cleavage by δ-secretase. Strikingly, CF3CN treatment evidently escalates BDNF levels. Both #11a and CF3CN display strong in vivo PK/PD properties and ability to suppress δ-secretase activity in the brain. Orally administrated CF3CN strongly activates TrkB that triggers active Akt to phosphorylate δ-secretase T322, preventing its proteolytic activation and mitigating AD pathologies. #11a or CF3CN significantly diminishes AD pathogenesis and improves cognitive functions with the combination exhibiting the maximal effect. Thus, our data support that these derivatives are strong pharmaceutical candidates for the treatment of AD.

Preclinical Bioavailability, Tissue Distribution, and Protein Binding Studies of Erinacine A, a Bioactive Compound from Hericium erinaceus Mycelia Using Validated LC-MS/MS Method.

Erinacine A, derived from the mycelia of Hericium erinaceus, has attracted much attention due to its neuroprotective properties. However, very few studies have been conducted on the bioavailability, tissue distribution, and protein binding of erinacine A. This study aimed to investigate the bioavailability, tissue distribution, and protein binding of erinacine A in Sprague-Dawley rats. After oral administration (po) and intravenous administration (iv) of 2.381 g/kg BW of the H. erinaceus mycelia extract (equivalent to 50 mg/kg BW of erinacine A) and 5 mg/kg BW of erinacine A, respectively, the absolute bioavailability of erinacine A was estimated as 24.39%. Erinacine A was detected in brain at 1 h after oral dosing and reached the peak at 8 h. Protein binding assay showed unbound erinacine A fractions in brain to blood ratio is close to unity, supporting passive diffusion as the dominating transport. Feces was the major route for the elimination of erinacine A. This study is the first to show that erinacine A can penetrate the blood-brain barrier of rats by the means of passive diffusion and thus support the development of H. erinaceus mycelia for the improvement of neurohealth.

In Vitro and In Vivo Efficacies of the Linear and the Cyclic Version of an All-d-Enantiomeric Peptide Developed for the Treatment of Alzheimer's Disease.

Multiple sources of evidence suggest that soluble amyloid ß (Aß)-oligomers are responsible for the development and progression of Alzheimer's disease (AD). In order to specifically eliminate these toxic Aß-oligomers, our group has developed a variety of all-d-peptides over the past years. One of them, RD2, has been intensively studied and showed such convincing in vitro and in vivo properties that it is currently in clinical trials. In order to further optimize the compounds and to elucidate the characteristics of therapeutic d-peptides, several rational drug design approaches have been performed. Two of these d-peptides are the linear tandem (head-to-tail) d-peptide RD2D3 and its cyclized form cRD2D3. Tandemization and cyclization should result in an increased in vitro potency and increase pharmacokinetic properties, especially crossing the blood-brain-barrier. In comparison, cRD2D3 showed a superior pharmacokinetic profile to RD2D3. This fact suggests that higher efficacy can be achieved in vivo at equally administered concentrations. To prove this hypothesis, we first established the in vitro profile of both d-peptides here. Subsequently, we performed an intraperitoneal treatment study. This study failed to provide evidence that cRD2D3 is superior to RD2D3 in vivo as in some tests cRD2D3 failed to show equal or higher efficacy.