Exploring the potential of natural and synthetic neuroprotective steroids against neurodegenerative disorders: A literature review

MRPS9-Mediated Regulation of the PI3K/Akt/mTOR Pathway Inhibits Neuron Apoptosis and Protects Ischemic Stroke

Neuronal apoptosis is crucial in the pathophysiology of ischemic stroke (IS), albeit its underly24ing mechanism remaining elusive. Investigating the mechanism of neuronal apoptosis in the context of IS holds substantial clinical value for enhancing the prognosis of IS patients. Notably, the MRPS9 gene plays a pivotal role in regulating mitochondrial function and maintaining structural integrity. Utilizing bioinformatic tactics and the extant gene expression data related to IS, we conducted differential analysis and weighted correlation network analysis (WGCNA) to select important modules. Subsequent gene interaction analysis via the STRING website facilitated the identification of the key gene-mitochondrial ribosomal protein S9 (MRPS9)-that affects the progression of IS. Moreover, possible downstream signaling pathways, namely PI3K/Akt/mTOR, were elucidated via Kyoto Encyclopedia of Gene and Genomes (KEGG) and Gene Ontology (GO) pathway analysis. Experimental models were established utilizing oxygen-glucose deprivation/reoxygenation (OGD/R) in vitro and middle cerebral artery occlusion/reperfusion (MCAO/R) in mice. Changes in gene and protein expression, as well as cell proliferation and apoptosis, were monitored through qPCR, WB, CCK8, and flow cytometry. An OGD/R cell model was further employed to investigate the role of MRPS9 in IS post transfusion of MRPS9 overexpression plasmids into cells. Further studies were conducted by transfecting overexpressed cells with PI3K/Akt/mTOR signaling pathway inhibitor LY294002 to unveil the mechanism of MRPS9 in IS. Bioinformatic analysis revealed a significant underexpression of MRPS9 in ischemic stroke patients. Correspondingly, in vitro experiments with HN cells subjected to OGD/R treatment demonstrated a marked reduction in MRPS9 expression, accompanied by a decline in cell viability, and an increase cell apoptosis. Notably, the overexpression of MRPS9 mitigated the OGD/R-induced decrease in cell viability and augmentation of apoptosis. In animal models, MRPS9 expression was significantly lower in the MCAO/R group compared to the sham surgery group. Further, the KEGG pathway analysis associated MRPS9 expression with the PI3K/Akt/mTOR signaling pathway. In cells treated with the specific PI3K/Akt/mTOR inhibitor LY294002, phosphorylation levels of Akt and mTOR were decreased, cell viability decreased, and apoptosis increased compared to the MRPS9 overexpression group. These findings collectively indicate that MRPS9 overexpression inhibits PI3K/Akt/mTOR pathway activation, thereby protecting neurons from apoptosis and impeding IS progression. However, the PI3K/Akt/mTOR inhibitor LY294002 is capable of counteracting the protective effect of MRPS9 overexpression on neuronal apoptosis and IS. Our observations underscore the potential protective role of MRPS9 in modulating neuronal apoptosis and in attenuating the pathophysiological developments associated with IS. This is achieved through the regulation of the PI3K/Akt/mTOR pathway. These insights forge new perspectives and propose novel targets for the strategic diagnosis and treatment of IS.

Bibliometric analysis of research on neurodegenerative diseases and single-cell RNA sequencing: Opportunities and challenges

Neurodegeneration, characterized by the progressive deterioration in neuronal structure or function, presents an elusive mechanism. The use of single-cell RNA sequencing (scRNA-seq) technology in the clinic is becoming increasingly prevalent in recent decades. This technology offers unparalleled cell-level insights into neurodegenerative diseases, establishing itself as a potent tool for elucidating these diseases underlying mechanisms. Here, we made a deep investigation for scRNA-seq research in neurodegenerative diseases using bibliometric analysis from 2009 to 2022. We observed a robust upward trajectory in the number of publications on this subject. The United States stood out as the principal contributor to this expanding field. Specifically, the University of California System exhibited notable research prowess in this field. Alzheimer disease and Parkinson disease were the diseases most frequently investigated. Key research hotspots include the creation of a molecular brain atlas and identification of vulnerable neuronal subpopulations and potential therapeutic targets at the transcriptomic level.

Synthesis of Some Benzothiazole Derivatives Based on 3-Hydroxypyridine-4-one and Benzaldehyde and Evaluation of Their β-Amyloid Aggregation Inhibition Using both Experimental Methods and Molecular Dynamic Simulation

Some novel inhibitors based on the (benzo[d]thiazol-2-yl)-1-phenylmethanimine derivatives were designed to reduce the aggregation process in Alzheimer's disease. These structures seem to mimic stilbene-like scaffold, while the benzothiazole moiety "locks" the thioflavin T binding site. Other inhibitors were designed based on 2-((benzo[d]thiazol-2-ylimino)methyl)-5-(benzyloxy)-1-methylpyridin-4(H)-one derivatives. Benzo[d]thiazol-2-amine derivatives were prepared by the reaction of aniline derivatives with ammonium thiocyanate in the presence of bromine/acetic acid. Then, the reaction of amines with benzaldehyde derivatives and 5-(benzyloxy)-1-methyl-4-oxo-1,4-dihydropyridine-2-carbaldehyde gave the desired compounds. The plate reader-based fibrillation assay was done to evaluate the inhibition of Aβ aggregation. Also, molecular dynamic simulation was carried out to clarify the interaction manner of the designed compounds with Aβ formation. The biological evaluation proved 5a and 7e as the best inhibitor of the Aβ aggregation. compound 5a in the concentration of 50 μM inhibited Aβ fibril formation better than 7e. MD simulation elucidated that the Aβ aggregation inhibitors in different concentrations represented different binding conformations throughout the entire or in one area of Aβ. MD showed the ligands in lower concentrations accumulate in an area of Aβ aggregations and separate one fibril from the aggregated Aβ. On the contrary, in higher concentrations, the ligands tend to be located through the entire Aβ.

Aminochalcones Attenuate Neuronal Cell Death under Oxidative Damage via Sirtuin 1 Activity

Encouraged by the lack of effective treatments and the dramatic growth in the global prevalence of neurodegenerative diseases along with various pharmacological properties of chalcone pharmacophores, this study focused on the development of aminochalcone-based compounds, organic molecules characterized by a chalcone backbone (consisting of two aromatic rings connected by a three-carbon α,β-unsaturated carbonyl system) with an amino group attached to one of the aromatic rings, as potential neuroprotective agents. Thus, the aminochalcone-based compounds in this study were designed by bearing a -OCH3 moiety at different positions on the ring and synthesized by the Claisen-Schmidt condensation. The compounds exhibited strong neuroprotective effects against hydrogen peroxide-induced neuronal death in the human neuroblastoma (SH-SY5Y) cell line (i.e., by improving cell survival, reducing reactive oxygen species production, maintaining mitochondrial function, and preventing cell membrane damage). The aminochalcone-based compounds showed mild toxicity toward a normal embryonic lung cell line (MRC-5) and a human neuroblastoma cell line, and were predicted to have preferable pharmacokinetic profiles with potential for oral administration. Molecular docking simulation indicated that the studied aminochalcones may act as competitive activators of the well-known protective protein, SIRT1, and provided beneficial knowledge regarding the essential key chemical moieties and interacting amino acid residues. Collectively, this work provides a series of four promising candidate agents that could be developed for neuroprotection.

Interpretable Machine Learning on Metabolomics Data Reveals Biomarkers for Parkinson's Disease

The use of machine learning (ML) with metabolomics provides opportunities for the early diagnosis of disease. However, the accuracy of ML and extent of information obtained from metabolomics can be limited owing to challenges associated with interpreting disease prediction models and analyzing many chemical features with abundances that are correlated and "noisy". Here, we report an interpretable neural network (NN) framework to accurately predict disease and identify significant biomarkers using whole metabolomics data sets without a priori feature selection. The performance of the NN approach for predicting Parkinson's disease (PD) from blood plasma metabolomics data is significantly higher than other ML methods with a mean area under the curve of >0.995. PD-specific markers that predate clinical PD diagnosis and contribute significantly to early disease prediction were identified including an exogenous polyfluoroalkyl substance. It is anticipated that this accurate and interpretable NN-based approach can improve diagnostic performance for many diseases using metabolomics and other untargeted 'omics methods.

The human microglial surveillant phenotype is preserved by de novo neurosteroidogenesis through the control of cholesterol homeostasis: Crucial role of 18 kDa Translocator Protein

Neurodegenerative disease-associated microglia commonly exhibit harmful cholesterol accumulation that impairs their ability to resolve the neuroinflammatory response, contributing to disease onset and progression. Neurosteroids, whose levels have been often found significantly altered in brain diseases, are the most potent endogenous anti-inflammatory molecules exerting beneficial effects on activities of brain cells, including microglia. For the first time, the impact of neurosteroidogenesis on cholesterol homeostasis for the immune surveillance phenotype maintenance was investigated in a human microglia in vitro model. To enhance and inhibit neurosteroidogenesis, pharmacological stimulation and knock-down of 18 kDa Translocator Protein (TSPO), which is involved in the neurosteroidogenesis rate-limiting step, were used as experimental approaches, respectively. The obtained results point to an essential autocrine control of neurosteroidogenesis in orchestrating cholesterol trafficking in human microglia. TSPO pharmacological stimulation ensured cholesterol turnover by strengthening cholesterol efflux systems and preserving healthy immune surveillant phenotype. Conversely, TSPO knock-down induced an impairment of the controlled interplay among cholesterol synthesis, efflux, and metabolism mechanisms, leading to an excessive cholesterol accumulation and acquisition of a chronically activated dysfunctional phenotype. In this model, the exogenous neurosteroid administration restored proper the cholesterol clearance. The TSPO ability in promoting native neurosteroidogenesis opens the way to restore cholesterol homeostasis, and thus to maintain microglia proper functionality for the treatment of neuroinflammation-related brain diseases.

Recent Advances in Bioactive Flavonoid Hybrids Linked by 1,2,3-Triazole Ring Obtained by Click Chemistry

As a result of the biological activities of natural flavonoids, several synthetic strategies aiming to obtain analogues with improved potency and/or pharmacokinetic profile have been developed. Since the triazole ring has been associated with several biological activities and metabolic stability, hybridization with a 1,2,3-triazole ring has been increasingly reported over the last years. The feasible synthesis through copper (I) catalyzed azide-alkyne cycloaddition (CuAAC) has allowed the accomplishment of several hybrids. Since 2017, almost 700 flavonoid hybrids conjugated with 1,2,3-triazole, including chalcones, flavones, flavanones and flavonols, among others, with antitumor, antimicrobial, antidiabetic, neuroprotective, anti-inflammatory, antioxidant, and antifouling activity have been reported. This review compiles the biological activities recently described for these hybrids, highlighting the mechanism of action and structure-activity relationship (SAR) studies.

Biological Activities of Extracts from Ageratum fastigiatum: Phytochemical Study and In Silico Target Fishing Approach

In the present study, the ethanolic extract from aerial parts of Ageratum fastigiatum was evaluated in vitro against epimastigote forms of Trypanosoma cruzi (Y strain), promastigote forms of Leishmania amazonensis (PH8 strain), and L. chagasi (BH400 strain). The extract was also evaluated against Staphylococcus aureus (ATCC 25 923), Escherichia coli (ATCC 11 775), Pseudomonas aeruginosa (ATCC 10 145), and Candida albicans (ATCC 36 802). The phytochemical screening was performed by thin-layer chromatography and high-performance liquid chromatography. The extract was fractionated using flash preparative chromatography. The ethanolic extract showed activity against T. cruzi, L. chagasi, and L. amazonensis and antimicrobial activity against S. aureus, E. coli, P. aeruginosa, and C. albicans. The phytochemical screening revealed coumarins, terpenes/sterols, and flavonoids in the ethanolic extract. In addition, the coumarin identified as ayapin was isolated from this extract. We also performed in silico prediction of potential biological activities and targets for compounds previously found in A. fastigiatum. Several predictions were confirmed both retrospectively and prospectively by experimental results described here or elsewhere. Some activities described in the in silico target fishing approach were validated by the ethnopharmacological use and known biological properties. Some new activities and/or targets were predicted and could guide future studies. These results suggest that A. fastigiatum can be an interesting source of substances with antiparasitic and antimicrobial activities.

Epibrassinolide prevents tau hyperphosphorylation via GSK3β inhibition in vitro and improves Caenorhabditis elegans lifespan and motor deficits in combination with roscovitine

Glycogen synthase kinase 3β (GSK3β) is considered an important element of glycogen metabolism; however, it has many other regulatory roles. Changes in the GSK3β signaling mechanism have been associated with various disorders, such as Alzheimer's disease (AD), type II diabetes, and cancer. Although the effects of GSK3β inhibitors on reducing the pathological effects of AD have been described, an effective inhibitor has not yet been developed. Epibrassinolide (EBR), a brassinosteroid (BR), is structurally similar to mammalian steroid hormones. Our studies have shown that EBR has an inhibitory effect on GSK3β in different cell lines. Roscovitine (ROSC), a cyclin-dependent kinase (CDK) inhibitor, has also been identified as a potential GSK3 inhibitor. Within the scope of this study, we propose that EBR and/or ROSC might have mechanistic action in AD models. To test this hypothesis, we used in vitro models and Caenorhabditis elegans (C. elegans) AD strains. Finally, EBR treatment successfully protected cells from apoptosis and increased the inhibitory phosphorylation of GSK3β. In addition, EBR and/or ROSC treatment had a positive effect on the survival rates of C. elegans strains. More interestingly, the paralysis phenotype of the C. elegans AD model due to Aβ42 toxicity was prevented by EBR and/or ROSC. Our findings suggest that EBR and ROSC administration have neuroprotective effects on both in vitro and C. elegans models via inhibitory GSK3β phosphorylation at Ser9.

The curcumin analog (PAC) suppressed cell survival and induced apoptosis and autophagy in oral cancer cells

PAC (3,5-Bis (4-hydroxy-3-methoxybenzylidene)-N-methyl-4-piperidone), a novel bioactive curcumin analog, has been reported to have anticancer properties against various tumors. However, the anti-cancer effects of PAC on oral cavity squamous cell carcinoma were not studied yet. Our aim is to investigate the anti-oral cancer properties of PAC in vitro, and determine the molecular mechanisms underlying these effects. Viability assays including MTT and LDH were conducted to measure cell proliferation. Flow cytometry-based cytotoxicity assay was performed to detect autophagic cell death and oxidative stress markers. Western blotting was used for measuring protein expression/activation in apoptotic, autophagic and pro-carcinogenic cellular signaling pathways. We demonstrated that PAC preferentially and, in a dose, -dependent way kills oral cancer cells, but was not toxic to normal human gingival cells. PAC destabilizes cell-cycle distributions, inhibits the expression of oncogenes (cyclin D1) and that of cyclin-dependent kinase inhibitor (p21^WAF1) is upregulated, increases the expression of p53 gene, and inhibits epithelial-mesenchymal transition markers in oral cancer cells. The PAC effect involve various signaling pathways including NF-κB, MAPK, Wnt, caspase-3/9 and PARP1. Finally, PAC demonstrated ability to induce autophagy, decrease production of reactive oxygen species, increase intracellular glutathione (GSH) activity, and reduce mitochondrial membrane potential in oral cancer cells. In conclusion, PAC inhibits the proliferation and increases the apoptosis and autophagy and oxidative stress of oral cancer cells. These effects involve ERK1/2, p38/JNK, NF-κB and Wnt cellular signaling pathways. Overall, our study suggests the potential use of PAC to treat oral cancer.

16-Substituted steroids alleviate LPS-induced neurodegenerative disorders in rats

The neuroprotective effects of some 16-substituted steroidal derivatives against the locomotive impairment and cognitive deficits in the lipopolysaccharide (LPS)-induced neuroinflammation model of rats have been investigated. The in vivo and in vitro evaluations include behavioural tests (actophotometer, block tests, Morris water maize and elevated plus maize), estimation of the biochemical parameters such as acetylcholinesterase, lipid peroxide, reactive oxygen, and nitric oxide species and molecular assays for the key proinflammatory mediators like Tumour Necrosis Factor alpha (TNF-α) and Interleukin 1 beta (IL- 1β) after 21 days of the treatment with the steroids. Behavioural and biochemical studies indicated impairment in the locomotor activity and cognitive dysfunction in rats after LPS treatment. In addition, higher levels of TNF-α and IL-1β in the blood serum of the rats were also noticed. However, significant alleviation of LPS-induced movement and memory disorders was observed in LPS-injected rats after treatment with 16-substituted steroidal derivatives 1-11. Furthermore the biochemical and molecular studies revealed suppression of oxidative and nitrosative stress, decreased acetylcholinesterase activity, and reduction of TNF-α and IL-1β levels after treatment with compounds 1-11. Among all the 16-substituted steroidal derivatives, the compounds 8 and 11 were found to be the most active neuroprotective agents and produced effects marginally better than standard drug dexamethasone.

Reactivity of steroidal 1-azadienes toward enamines: an approach to novel chiral penta- and hexacyclic steroids

The chemical behavior of steroidal N-sulfonyl-1-azadienes toward carbonyl compounds, in the presence of pyrrolidine, is described. With aldehydes, these azadienes participate in hetero-Diels-Alder reactions with the in situ generated enamines. The stereoselectivity results from the approach of the dienophiles from the less hindered α-face of the steroid, with the pyrrolidine moiety endo and retention of the enamine trans geometry. This diastereoselective synthetic methodology led to a new class of chiral pentacyclic steroids. Interestingly, the studied steroidal scaffolds follow a different mechanistic pathway with cyclic ketones. They undergo a diastereoselective annulation reaction, under enamine catalysis, affording chiral hexacyclic steroids.

Synthesis and Biological Evaluations of Electrophilic Steroids Inspired by the Taccalonolides

Natural products have served as inspirational scaffolds for the design and synthesis of novel antineoplastic agents. Here we present our preliminary efforts on the synthesis and biological evaluation of a new class of electrophilic steroids inspired by the naturally occurring taccalonolides. We demonstrate that these simplified analogs exhibit highly persistent antiproliferative properties similar to the taccalonolides and retain activity against resistant cancer cell lines that warrants further preclinical development.

Pharmacological effects and mechanisms of muscone

Musk, the dried secretion from the preputial follicles of the male musk deer (genus Moschus), possesses various pharmacological activities and has been used extensively in traditional Chinese medicine for thousands of years. Muscone is the main active ingredient of musk and exerts pharmacological effects similar to those of musk. Although muscone was notably used to treat various disorders and diseases, such as neurological disorders, chronic inflammation and ischemia-reperfusion injury, most of the mechanisms of the pharmacological action of muscone remain unclear because of slow progress in research before the 21st century. In recent years, the pharmacological activities and mechanisms of muscone have been clarified. The present article summarizes the pharmacological and biological studies on cerebrovascular disease, cardiovascular disease, neurological effects, cancer and others and the associated mechanisms of the action of muscone to date.

Implantable Nanosensors for Human Steroid Hormone Sensing In Vivo Using a Self-Templating Corona Phase Molecular Recognition

Dynamic measurements of steroid hormones in vivo are critical, but steroid sensing is currently limited by the availability of specific molecular recognition elements due to the chemical similarity of these hormones. In this work, a new, self-templating synthetic approach is applied using corona phase molecular recognition (CoPhMoRe) targeting the steroid family of molecules to produce near infrared fluorescent, implantable sensors. A key limitation of CoPhMoRe has been its reliance on library generation for sensor screening. This problem is addressed with a self-templating strategy of polymer design, using the examples of progesterone and cortisol sensing based on a styrene and acrylic acid copolymer library augmented with an acrylated steroid. The pendant steroid attached to the corona backbone is shown to self-template the phase, providing a unique CoPhMoRE design strategy with high efficacy. The resulting sensors exhibit excellent stability and reversibility upon repeated analyte cycling. It is shown that molecular recognition using such constructs is viable even in vivo after sensor implantation into a murine model by employing a poly (ethylene glycol) diacrylate (PEGDA) hydrogel and porous cellulose interface to limit nonspecific absorption. The results demonstrate that CoPhMoRe templating is sufficiently robust to enable a new class of continuous, in vivo biosensors.

The effects of hydro-ethanolic extract of Capparis spinosa (C. spinosa) on lipopolysaccharide (LPS)-induced inflammation and cognitive impairment: Evidence from in vivo and in vitro studies

ETHNOPHARMACOLOGICAL RELEVANCE

Capparis spinose (C. spinosa) belonging to Capparaeae, originates from dry areas in the west or central Asia and Mediterranean basin. For thousands of years, C. spinosa has been reported to be used as a therapeutic traditional medicine to relieve various ailments including rheumatism, pain and inflammatory diseases.

AIM OF THE STUDY

There are several studies mentioning that systemic inflammation results in learning and memory impairments through the activation of microglia. The objective of this study was to investigate the effect of C. spinosa on both in vivo and in vitro models of neuroinflammation and cognitive impairment using lipopolysaccharide (LPS).

MATERIALS AND METHODS

In vivo: 40 male rats were used in the present study. Cognitive impairment was induced using LPS (1 mg/kg/d; i.p.) for 4 weeks. Treatment with C. spinosa (100 and 300 mg/kg/d; p.o.) was performed 1 h before LPS administration. At the end of the experiment, rats were undergone for behavioral and biochemical analysis. In vitro: Primary microglia isolated from mouse was used in the present study. The cells were pretreated with C. spinosa extract (10-300 μg/ml) and then stimulated with LPS (1 μg/ml). The expression levels of inflammatory and anti-inflammatory cytokines were elucidated using Real-Time PCR and ELISA methods.

RESULTS

The escape latency in the Morris water maze test in the LPS group was significantly greater than the control group (p < 0.001), while, in extract-treated groups, it was less than the LPS group (p < 0.001). Additionally, we found that the levels of IL-1β, TNF-α, and iNOS/Arg-1 ratio was also significantly lower in extract-treated groups than the LPS group (p < 0.001). The results revealed that C. spinosa extract significantly reduced the levels of TNF-α, iNOS, COX-2, IL-1β, IL-6, NO and PGE2, and the ratios of iNOS/Arg-1 and NO/urea, following the LPS-induced inflammation in microglia (p < 0.001).

CONCLUSIONS

Our finding provides evidence that C. spinosa has a neuroprotective effect, and might be considered as an effective therapeutic agent for the treatment of neurodegenerative diseases that are accompanied by microglial activation, such as AD.

Effects of crocin in reducing DNA damage, inflammation, and oxidative stress in multiple sclerosis patients: A double-blind, randomized, and placebo-controlled trial

Multiple sclerosis (MS) is an autoimmune disease in which the immune system attacks the nerve cells, resulting in neurological disorders. Oxidative stress, free radicals, and neuritis have important roles in MS pathogenesis. Here, we aim to evaluate the effect of crocin on inflammatory markers, oxidative damage, and deoxyribonucleic acid (DNA) damage in the blood of patients with MS. A total of 40 patients were divided into two groups, drug and placebo-treated groups, using random assignment. Participants of the intervention and control groups received two crocin capsules or placebo per day for 28 days, respectively. Findings revealed a significant decrease in the level of important pathogenic factors in MS, including lipid peroxidation, DNA damage, tumor necrosis factor-alpha, and interleukin 17 as well as a significant increase in the total antioxidant capacity in the serum of patients treated with crocin compared with the placebo group. Our results suggest the beneficial and therapeutic effects of crocin in MS.

16,17-N'-(alky/arylsulfonyl)pyrazoline substituted neuroprotective heterosteroids: Synthesis, molecular docking and preclinical efficacy/toxicity studies in rodents

The synthesis and neuroprotective efficacy and toxicity studies of a new series of 16,17-N'-(alkyl/arylsulfonyl)pyrazolinyl steroids is presented. Significant suppression of the overexpressed acetylcholinesterase and lipid peroxidation, marked reduction of nitrite, oxidative stress and TNF-α levels and noticeable improvement in cognitive and locomotor functions were observed after treatment with the newly synthesized steroids 2-4a-d in the LPS-treated animal models. Higher neuroprotective effects were produced by some of the pyrazolinyl steroids in comparison to the reference drugs celecoxib and dexamethasone. N'-(4-fluorobenzenesulfonyl) derivative 4c showed the most promising effects on all the analyzed parameters and is the most potent molecule among all compounds of this series. Acute toxicity studies on the most active steroids 2-4c at 50 mg/kg did not reveal any toxic effects on animals, however hepatitis and chronic nephritis were observed in histological examination of liver and kidney of mice after 28 days of treatment. The pyrazolinyl steroids 2-4a-d could be considered as promising candidates for the designing of novel multitarget-directed neuroprotectives for an effective therapy of AD and PD.

Activation of Adrenal Steroidogenesis and an Improvement of Mood Balance in Postmenopausal Females after Spa Treatment Based on Physical Activity

Spa treatment can effectively reestablish mood balance in patients with psychiatric disorders. In light of the adrenal gland’s role as a crossroad of psychosomatic medicine, this study evaluated changes in 88 circulating steroids and their relationships with a consolidation of somatic, psychosomatic and psychiatric components from a modified N-5 neurotic questionnaire in 46 postmenopausal 50+ women with anxiety-depressive complaints. The patients underwent a standardized one-month intervention therapy with physical activity and an optimized daily regimen in a spa in the Czech Republic. All participants were on medication with selective serotonin reuptake inhibitors. An increase of adrenal steroidogenesis after intervention indicated a reinstatement of the hypothalamic-pituitary-adrenal axis. The increases of many of these steroids were likely beneficial to patients, including immunoprotective adrenal androgens and their metabolites, neuroactive steroids that stimulate mental activity but protect from excitotoxicity, steroids that suppress pain perception and fear, steroids that consolidate insulin secretion, and steroids that improve xenobiotic clearance. The positive associations between the initial values of neurotic symptoms and their declines after the intervention, as well as between initial adrenal activity and the decline of neurotic symptoms, indicate that neurotic impairment may be alleviated by such therapy provided that the initial adrenal activity is not seriously disrupted.

Current Drugs and Potential Future Neuroprotective Compounds for Parkinson's Disease

The research progress of understanding the etiology and pathogenesis of Parkinson's disease (PD) has yet lead to the development of some clinical approaches intended to treat cognitive and behavioral symptoms, such as memory and per-ception disorders. Despite the major advances in different genetic causes and risk factors for PD, which share common pathways to cell dysfunction and death, there is not yet a complete model of PD that can be used to accurately predict the ef-fect of drugs on disease progression. Clinical trials are also important to test any novel neuro-protective agent, and recently there have been great advances in the use of anti-inflammatory drugs and plant flavonoid antioxidants to protect against spe-cific neuronal degeneration and its interference with lipid and cholesterol metabolism. The increasing knowledge of the mo-lecular events underlying the degenerative process of PD has stimulated research to identify natural compounds capable of halting or slowing the progress of neural deterioration. Polyphenols and flavonoids, which play a neuroprotective role in a wide array of in vitro and in vivo models of neurological disorders, emerged from among the multi-target bio-agents found mainly in plants and microorganisms. This review presents a detailed overview of the multimodal activities of neuroprotec-tive bio-agents tested so far, emphasizing their neurorescue/neuroregenerative activity. The brain-penetrating property of bio-agents may make these compounds an important class of natural drugs for the treatment of neurodegenerative diseases. Alt-hough there are numerous studies demonstrating beneficial effects in the laboratory by identifying critical molecular targets, the clinical efficacy of these neuroprotective treatments remains to be proven accurately.

A Novel Synthetic Steroid of 2β,3α,5α-Trihydroxy-androst-6-one Alleviates the Loss of Rat Retinal Ganglion Cells Caused by Acute Intraocular Hypertension via Inhibiting the Inflammatory Activation of Microglia

Neuroinflammation has been well recognized as a key pathological event in acute glaucoma. The medical therapy of acute glaucoma mainly focuses on lowering intraocular pressure (IOP), while there are still scarce anti-inflammatory agents in the clinical treatment of acute glaucoma. Here we reported that β,3α,5α-trihydroxy-androst-6-one (sterone), a novel synthetic polyhydric steroid, blocked neuroinflammation mediated by microglia/macrophages and alleviated the loss of retinal ganglion cells (RGCs) caused by acute intraocular hypertension (AIH). The results showed that sterone significantly inhibited the morphological changes, the up-regulation of inflammatory biomarker ionized calcium-binding adapter molecule 1 (Iba-1), and the mRNA increase of proinflammatory tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and interleukin-6 (IL-6) induced by lipopolysaccharide (LPS) in BV2 microglia and RAW264.7 macrophages. Moreover, immunofluorescence and western blotting analysis revealed that sterone markedly abrogated the nuclear translocation and phosphorylation of nuclear factor-κB (NF-κB) p65 subunit. Furthermore, sterone significantly suppressed the inflammatory microglial activation and RGCs’ reduction caused by retinal ischemia/reperfusion (I/R) injury in a rat AIH model. These results suggest sterone may be a potential candidate in the treatment of acute glaucoma caused by microglial activation-mediated neuroinflammatory injury.

Intracochlear administration of steroids with a catheter during human cochlear implantation: a safety and feasibility study

Suppression of foreign body reaction, improvement of electrode-nerve interaction, and preservation of residual hearing are essential research topics in cochlear implantation. Intracochlear pharmaco- or cell-based therapies can open new horizons in this field. Local drug delivery strategies are desirable as higher local concentrations of agents can be realized and side effects can be minimized compared to systemic administrations. When administered locally at accessible, basal parts of the cochlea, drugs reach apical regions later and in much lower concentrations due to poor diffusion patterns in cochlear fluids. Therefore, new devices are needed to warrant rapid distribution of agents into all parts of the cochlea. Five patients received a deep intracochlear injection of triamcinolone with a specifically designed cochlear catheter during cochlear implantation right before inserting a cochlear implant electrode. As a measure for formation of fibrous tissue around the electrode, electrical impedances were measured in the operation room and over 4 months thereafter. No adverse events were observed peri- and postoperatively. The handling of the device was easy. Severe damage to the microstructure of the cochlea was excluded as far as possible by cone beam computed tomography and vestibular testing. A delayed rise of the impedances was seen in the catheter group compared to controls over all regions of the cochlea. A statistical significance, however, was only obtained at the midregion of the cochlea. Consequently, the cochlear catheter is a safe and feasible device for local drug delivery of pharmaceutical agents into deeper regions of the cochlea.

A synthetic snake-venom-based tripeptide (Glu-Val-Trp) protects PC12 cells from MPP+ toxicity by activating the NGF-signaling pathway

Venom small peptides that target neurotrophin receptors might be beneficial in neurodegeneration, including Parkinsońs disease (PD). Their small size, ease of synthesis, structural stability and target selectivity make them important tools to overcome the limitations of endogenous neurotrophins as therapeutic agents. Additionally, they might be optimized to improve resistance to enzymatic degradation, bioavailability, potency and, mainly, lipophilicity, important to cross the blood brain barrier (BBB). Here, we evaluated the neuroprotective effects and mechanisms of the synthetic snake-venom-based peptide p-BTX-I (Glu-Val-Trp) in PC12 cells treated with MPP⁺ (1-methyl-4-phenylpyridinium), a dopaminergic neurotoxin that induces Parkinsonism in vivo. The peptide p-BTX-I induced neuritogenesis, which was reduced by (i) k252a, antagonist of the NGF-selective receptor, trkA (tropomyosin receptor kinase A); (ii) LY294002, inhibitor of the PI3 K/AKT pathway and (iii) U0126, inhibitor of the MAPK-ERK pathway. Besides that, p-BTX-I also increased the expression of GAP-43 and synapsin, which are molecular markers of axonal growth and synaptic communication. In addition, the peptide increased the viability and differentiation of cells exposed to MPP⁺, known to inhibit neuritogenesis. Altogether, our findings suggest that the synthetic peptide p-BTX-I protects PC12 cells from MPP⁺ toxicity by a mechanism that mimics the neurotrophic action of NGF. Therefore, the molecular structure of p-BTX-I might be relevant in the development of drugs aimed at restoring the axonal connectivity in neurodegenerative processes.

Evidence for effective structure-based neuromodulatory effects of new analogues of neurosteroid allopregnanolone

The neurosteroid allopregnanolone (AP) modulates neuroendocrine/neurobiological processes, including hypothalamic-pituitary-adrenocortical activities, pain, anxiety, neurogenesis and neuroprotection. These observations raised the hope of developing AP-based therapies against neuroendocrine and/or neurodegenerative disorders. However, the pleiotropic actions of AP, particularly its cell-proliferation-promoting effects, hamper the development of selective/targeted therapies. For example, although AP-induced neurogenesis may serve to compensate neuronal loss in degenerative brains, AP-evoked cell-proliferation is contraindicated for steroid-sensitive cancer patients. To foster progress, we synthesised 4 novel AP analogues of neurosteroids (ANS) designated BR053 (12-oxo-epi-AP), BR297 (O-allyl-epi-AP), BR351 (O-allyl-AP) and BR338 (12-oxo-AP). First, because AP is well-known as allosteric modulator of GABAA receptors (GABAA-R), we used the electrophysiological patch-clamp technique to determine the structure-activity relationship of our ANS on GABAA-activated current in NCB20 cells expressing functional GABAA-R. We found that the addition of 12-oxo-group did not significantly change the respective positive or negative allosteric effects of 3α-AP or 3β-(epi)-AP analogues. Importantly, substitution of the 3α-hydroxyl-group by 3α-O-allyl highly modified the ANS activities. Unlike AP, BR351 induced a long-lasting desensitisation/inhibition of GABAA-R. Interestingly, replacement of the 3β-hydroxyl by 3β-O-allyl (BR297) completely reversed the activity from negative to positive allosteric action. In a second step, we compared the actions of AP and ANS on SH-SY5Y neuronal cell viability/proliferation using MTT-reduction assays. Different dose-response curves were demonstrated for AP and the ANS. By contrast to AP, BR297 was totally devoid of cell-proliferative effect. Finally, we compared AP and ANS abilities to protect against oxidative stress-induced neuronal death pivotally involved in neurodegenerative diseases. Both BR351 and BR297 had notable advantages over AP in protecting SH-SY5Y cells against oxidative stress-induced death. Thus, BR297 appears to be a potent neuroprotective compound devoid of cell-proliferative activity. Altogether, our results suggest promising perspectives for the development of neurosteroid-based selective and effective strategies against neuroendocrine and/or neurodegenerative disorders.