Minocycline for short-term neuroprotection

Results from a Double-Blind, Randomized, Placebo-Controlled, Single-Dose, Crossover Trial of Lovastatin or Minocycline in Fragile X Syndrome

Introduction: Treatment studies in FMR1 knockout rodent models have found that minocycline and lovastatin each improve synaptic, neurological, and behavioral functioning, and open-label chronic dosing studies in human patients with fragile X syndrome (FXS) have demonstrated modest clinical improvements. Findings from blinded studies are mixed, and there is a limited understanding of electrophysiological target engagement that would facilitate cross-species translational studies. Smaller-scale, acute (e.g., single-dose) drug studies may speed treatment identification by detecting subtle electrophysiological and behavioral changes. Materials and Methods: Twenty-nine participants with FXS (31% female) ages 15-45 years completed a randomized, double-blind, crossover study in which they received a single oral dose of 40 mg of lovastatin, 270 mg of minocycline, or placebo, with a 2-week washout period between dosing visits. Participants completed a comprehensive neuropsychological battery and three EEG paradigms (resting state; auditory chirp; auditory habituation) before and 4 hours after dosing. Results: No serious adverse events were reported, and both drugs were well-tolerated. Compared with placebo, there were no overall treatment effects for any outcomes, including EEG, but several modest drug responses varied as a function of sex and age. Lovastatin treatment was associated with improved spatial awareness in older participants and females compared with minocycline and placebo. Discussion: We show that single-dose drug studies are highly feasible in FXS and that patients with FXS can complete a range of EEG and behavioral tasks, many of which have been shown to be reliable and may therefore be sensitive to subtle drug target engagement. Conclusions: Acute single doses of lovastatin or minocycline did not lead to changes in electrophysiological or performance-based measures. This may be due to the limited effects of these drugs in human patients or limited acute effects relative to chronic dosing. However, the study design was further validated for use in neurodevelopmental populations.

In Silico Study of the Potential Inhibitory Effects on Escherichia coli DNA Gyrase of Some Hypothetical Fluoroquinolone-Tetracycline Hybrids

BACKGROUND/OBJECTIVES

Despite the discovery of antibiotics, bacterial infections persist globally, exacerbated by rising antimicrobial resistance that results in millions of cases, increased healthcare costs, and more extended hospital stays. The urgent need for new antibacterial drugs continues as resistance evolves. Fluoroquinolones and tetracyclines are versatile antibiotics that are effective against various bacterial infections. A hybrid antibiotic combines two or more molecules to enhance antimicrobial effectiveness and combat resistance better than monotherapy. Fluoroquinolones are ideal candidates for hybridization due to their potent bactericidal effects, ease of synthesis, and ability to form combinations with other molecules.

METHODS

This study explored the mechanisms of action for 40 hypothetical fluoroquinolone-tetracycline hybrids, all of which could be obtained using a simple, eco-friendly synthesis method. Their interaction with Escherichia coli DNA Gyrase and similarity to albicidin were evaluated using the FORECASTER platform.

RESULTS

Hybrids such as Do-Ba, Mi-Fi, and Te-Ba closely resembled albicidin in physicochemical properties and FITTED Scores, while Te-De surpassed it with a better score. Similar to fluoroquinolones, these hybrids likely inhibit DNA synthesis by binding to enzyme-DNA complexes.

CONCLUSIONS

These hybrids could offer broad-spectrum activity and help mitigate bacterial resistance, though further in vitro and in vivo studies are needed to validate their potential.

Preventive, rescue and reparative neuroprotective strategies for the fetus and neonate

Neonatal encephalopathy remains a major contributor to death and disability around the world. Acute hypoxia-ischaemia before, during or after birth creates a series of events that can lead to neonatal brain injury. Understanding the evolution of injury underpinned the development of therapeutic hypothermia. This review discusses the determinants of injury, including maturity, the pattern of exposure to HI, impaired placental function, often associated with fetal growth restriction and in the long-term, socio-economic deprivation. Chorioamnionitis has been associated with the presence of NE, but it is important to note that experimentally, inflammation can either sensitize to greater neural injury after HI or alleviate injury, depending on its precise timing. As fetal surveillance tools improve it is likely that improved detection of specific pathways will offer future opportunities for preventive and reparative interventions in utero and after birth.

In situ formed aldehyde-modified hyaluronic acid hydrogel with polyelectrolyte complexes of aldehyde-modified chondroitin sulfate and gelatin: An approach for minocycline delivery

Polysaccharides like hyaluronan (HA) and chondroitin sulfate (CS) are native of the brain's extracellular matrix crucial for myelination and brain maturation. Despite extensive research on HA and CS as drug delivery systems (DDS), their high water solubility limits their application as drug carriers. This study introduces an injectable DDS using aldehyde-modified hyaluronic acid (HAOX) hydrogel containing polyelectrolyte complexes (PEC) formed with calcium, gelatin, and either CS or aldehyde-modified CS (CSOX) to deliver minocycline for Multiple Sclerosis therapy. PECs with CSOX enable covalent crosslinking to HAOX, creating immobilized PECs (HAOX_PECOX), while those with CS remain unbound (HAOX_PECS). The in situ forming DDS can be administered via a 20 G needle, with rapid gelation preventing premature leakage. The system integrates into an implanted device for minocycline release through either Fickian or anomalous diffusion, depending on PEC immobilization. HAOX_PECOX reduced burst release by 88 %, with a duration of 127 h for 50 % release. The DDS exhibited an elastic modulus of 3800 Pa and a low swelling ratio (0-1 %), enabling precise control of minocycline release kinetics. Released minocycline reduced IL-6 secretion in the Whole Blood Monocytes Activation Test, suggesting that DDS formation may not alter the biological activity of the loaded drug.

Toward discovering a novel family of peptides targeting neuroinflammatory states of brain microglia and astrocytes

Microglia are immune-derived cells critical to the development and healthy function of the brain and spinal cord, yet are implicated in the active pathology of many neuropsychiatric disorders. A range of functional phenotypes associated with the healthy brain or disease states has been suggested from in vivo work and were modeled in vitro as surveying, reactive, and primed sub-types of primary rat microglia and mixed microglia/astrocytes. It was hypothesized that the biomolecular profile of these cells undergoes a phenotypical change as well, and these functional phenotypes were explored for potential novel peptide binders using a custom 7 amino acid-presenting M13 phage library (SX7) to identify unique peptides that bind differentially to these respective cell types. Surveying glia were untreated, reactive were induced with a lipopolysaccharide treatment, recovery was modeled with a potent anti-inflammatory treatment dexamethasone, and priming was determined by subsequently challenging the cells with interferon gamma. Microglial function was profiled by determining the secretion of cytokines and nitric oxide, and expression of inducible nitric oxide synthase. After incubation with the SX7 phage library, populations of SX7-positive microglia and/or astrocytes were collected using fluorescence-activated cell sorting, SX7 phage was amplified in Escherichia coli culture, and phage DNA was sequenced via next-generation sequencing. Binding validation was done with synthesized peptides via in-cell westerns. Fifty-eight unique peptides were discovered, and their potential functions were assessed using a basic local alignment search tool. Peptides potentially originated from proteins ranging in function from a variety of supportive glial roles, including synapse support and pruning, to inflammatory incitement including cytokine and interleukin activation, and potential regulation in neurodegenerative and neuropsychiatric disorders.

Minocycline Acts as a Neuroprotective Agent Against Tramadol-Induced Neurodegeneration: Behavioral and Molecular Evidence

Background

Previous evidence indicates that tramadol (TRA) can lead to neurodegenerative events and minocycline (MIN) has neuroprotective properties.

Aim of the Study

The current research evaluated the neuroprotective effects of MIN for TRA-promoted neurodegeneration.

Methods

Sixty adult male rats were placed into the following groups: 1 (received 0.7 ml/rat of normal saline, IP), 2 (received 50 mg/kg of TRA, i.p.), 3, 4, 5 (administered TRA as 50 mg/kg simultaneously with MIN at 20, 40, and 60 mg/kg, IP, respectively), and 6 (received MIN alone as 60 mg/kg, IP). The treatment procedure was 21 days. An open field test (OFT) was used to measure motor activity and anxiety-related behavior. Furthermore, oxidative stress; hippocampal inflammation; apoptotic parameters as well as activity of mitochondrial complexes I, II, III, and IV; ATP levels; and mitochondrial membrane potential (MMP) were evaluated. In addition, histomorphological alteration was assessed in two regions of the hippocampus: Cornu Ammonis (CA1) and dentate gyrus (DG).

Results

MIN treatment could inhibit TRA-induced anxiety and motor activity disturbances (P < 0.05). In addition, MIN could attenuate reactive oxygen species (ROS), H2O2, oxidized glutathione (GSSG), and malondialdehyde (MDA) level (P < 0.05), while there was increased reduced glutathione (GSH), total antioxidant capacity (TAC), ATP, MMP, and BCL2 levels (P < 0.05) and also elevation of SOD, GPX, GSR (P < 0.05), and mitochondrial complexes I, II, III, and IV activity (P < 0.05) in TRA-treated rats. In consistence with these findings, MIN could reduce TNF/TNF-α, IL1B/IL1-β, BAX, and CASP3 levels (P < 0.05) in TRA-treated rats. MIN also restored the quantitative (P < 0.05) and qualitative histomorphological sequels of TRA in both CA1 and DG areas of the hippocampus.

Conclusions

MIN probably has repositioning capability for inhibition of TRA-induced neurodegeneration via modulation of inflammation, oxidative stress, apoptosis, and mitochondrial disorders.

Systematic analysis of the adverse effects of commonly used clinical tetracycline drugs based on the FAERS database

BACKGROUND

Tetracyclines are a class of antibacterial drugs commonly used in clinical practice, but there is no systematic analysis of the adverse effects (AEs) of these drugs. We performed such pharmacovigilance analyses using the US Food and Drug Administration Adverse Event Reporting System (FAERS) database to explore tetracycline-related AEs.

RESEARCH DESIGN AND METHODS

We used the pharmacovigilance analysis tool Open Vigil 2.1 to access FAERS data and obtained AE reports from January 2004 to June 2023, including doxycycline, minocycline, tigecycline, omadacycline, sarecycline, and eravacycline as the top suspect drugs. The signal value of the AE of the analyzed drug was calculated by the reporting odds ratio (ROR).

RESULTS

A total of 15,020 cases were identified by analyzing drugs. In terms of adverse signals, doxycycline caused gastrointestinal mucosal necrosis (ROR = 1699.652); minocycline was reported to cause bone hyperpigmentation (ROR = 30976.223); tigecycline is responsible for blood fibrinogen decreased (ROR = 1714.078).

CONCLUSIONS

AE reports of tetracycline drugs varied significantly. We found some AEs not mentioned in the instruction, such as the ototoxicity of tetracyclines. Doxycycline was associated with psychiatric side effects; minocycline presented in thyroid and skin tissue-associated tumors; abnormal signals were detected with eravacycline in the blood system.

Current state of neuroprotective therapy using antibiotics in human traumatic brain injury and animal models

TBI is a leading cause of death and disability in young people and older adults worldwide. There is no gold standard treatment for TBI besides surgical interventions and symptomatic relief. Post-injury infections, such as lower respiratory tract and surgical site infections or meningitis are frequent complications following TBI. Whether the use of preventive and/or symptomatic antibiotic therapy improves patient mortality and outcome is an ongoing matter of debate. In contrast, results from animal models of TBI suggest translational perspectives and support the hypothesis that antibiotics, independent of their anti-microbial activity, alleviate secondary injury and improve neurological outcomes. These beneficial effects were largely attributed to the inhibition of neuroinflammation and neuronal cell death. In this review, we briefly outline current treatment options, including antibiotic therapy, for patients with TBI. We then summarize the therapeutic effects of the most commonly tested antibiotics in TBI animal models, highlight studies identifying molecular targets of antibiotics, and discuss similarities and differences in their mechanistic modes of action.

Minocycline declines interleukin-1ß-induced apoptosis and matrix metalloproteinase expression in C28/I2 chondrocyte cells: an in vitro study on osteoarthritis

Osteoarthritis (OA) is a degenerative joint disease that occurs with aging. In its late phases, it is determined by the loss of chondrocytes and the breakdown of the extracellular matrix, resulting in pain and functional impairment. Interleukin-1 beta (IL-1β) is increased in the injured joints and contributes to the OA pathobiology by inducing chondrocyte apoptosis and up-regulation of matrix metalloproteinases (MMPs). Here, we aimed to understand whether minocycline could protect chondrocytes against the IL-1β-induced effects. The human C28/I2 chondrocyte cell line was treated with IL-1β or IL-1β plus minocycline. Cell viability/toxicity, cell cycle progression, and apoptosis were assessed with MMT assay and flow cytometry. Expression of apoptotic genes and MMPs were evaluated with qRT-PCR and western blotting. IL-1β showed a significant cytotoxic effect on the C28/I2 chondrocyte cells. The minocycline effective concentration (EC50) significantly protected the C28/I2 cells against the IL-1β-induced cytotoxic effect. Besides, minocycline effectively lowered IL-1β-induced sub-G1 cell population increase, indicating the minocycline anti-apoptotic effect. When assessed by real-time PCR and western blotting, the minocycline treatment group showed an elevated level of Bcl-2 and a significant decrease in the mRNA and protein expression of the apoptotic markers Bax and Caspase-3 and Matrix metalloproteinases (MMPs) such as MMP-3 and MMP-13. In conclusion, IL-1β promotes OA by inducing chondrocyte death and MMPs overexpression. Treatment with minocycline reduces these effects and decreases the production of apoptotic factors as well as the MMP-3 and MMP-13. Minocycline might be considered as an anti-IL-1β therapeutic supplement in the treatment of osteoarthritis. See also the graphical abstract(Fig. 1).

Broadening horizons: ferroptosis as a new target for traumatic brain injury

Traumatic brain injury (TBI) is a leading cause of death and disability worldwide, with ~50 million people experiencing TBI each year. Ferroptosis, a form of regulated cell death triggered by iron ion-catalyzed and reactive oxygen species-induced lipid peroxidation, has been identified as a potential contributor to traumatic central nervous system conditions, suggesting its involvement in the pathogenesis of TBI. Alterations in iron metabolism play a crucial role in secondary injury following TBI. This study aimed to explore the role of ferroptosis in TBI, focusing on iron metabolism disorders, lipid metabolism disorders and the regulatory axis of system Xc-/glutathione/glutathione peroxidase 4 in TBI. Additionally, we examined the involvement of ferroptosis in the chronic TBI stage. Based on these findings, we discuss potential therapeutic interventions targeting ferroptosis after TBI. In conclusion, this review provides novel insights into the pathology of TBI and proposes potential therapeutic targets.

Effects of Red ginseng on neuroinflammation in neurodegenerative diseases

Red ginseng (RG) is widely used as a herbal medicine. As the human lifespan has increased, numerous diseases have developed, and RG has also been used to treat various diseases. Neurodegenerative diseases are major problems that modern people face through their lives. Neurodegenerative diseases, including Alzheimer's disease, Parkinson's disease, Huntington's disease, and amyotrophic lateral sclerosis are featured by progressive nerve system damage. Recently, neuroinflammation has emerged as a degenerative factor and is an immune response in which cytokines with nerve cells that constitute the nervous system. RG, a natural herbal medicine with fewer side effects than chemically synthesized drugs, is currently in the spotlight. Therefore, we reviewed studies reporting the roles of RG in treating neuroinflammation and neurodegenerative diseases and found that RG might help alleviate neurodegenerative diseases by regulating neuroinflammation.

New insight on microglia activation in neurodegenerative diseases and therapeutics

Microglia are immune cells within the central nervous system (CNS) closely linked to brain health and neurodegenerative diseases such as Alzheimer's disease and Parkinson's disease. In response to changes in the surrounding environment, microglia activate and change their state and function. Several factors, example for circadian rhythm disruption and the development of neurodegenerative diseases, influence microglia activation. In this review, we explore microglia's function and the associated neural mechanisms. We elucidate that circadian rhythms are essential factors influencing microglia activation and function. Circadian rhythm disruption affects microglia activation and, consequently, neurodegenerative diseases. In addition, we found that abnormal microglia activation is a common feature of neurodegenerative diseases and an essential factor of disease development. Here we highlight the importance of microglia activation in neurodegenerative diseases. Targeting microglia for neurodegenerative disease treatment is a promising direction. We introduce the progress of methods targeting microglia for the treatment of neurodegenerative diseases and summarize the progress of drugs developed with microglia as targets, hoping to provide new ideas for treating neurodegenerative diseases.

Brief Report: A Double-Blind, Placebo-Controlled, Crossover, Proof-of-Concept Study of Minocycline in Autism Spectrum Disorder

Neuroinflammatory mechanisms have been implicated in the pathophysiology of autism spectrum disorder (ASD). Minocycline is a matrix metalloproteinase inhibitor 9 (MMP9) inhibitor tetracycline antibiotic with known anti-inflammatory properties. In preclinical animal models of ASD, minocycline has demonstrated potential positive effects on phenotypes that may have relevance to ASD. We conducted the first placebo-controlled study of minocycline in ASD. This double-blind, placebo-controlled crossover trial employed four week treatment periods with a two week washout period. Twenty-four 12-22 year olds (mean age 17.4 years; range 12.9-22.5 years) with ASD were enrolled. Overall minocycline was well tolerated. No minocycline-associated clinical changes were noted with treatment on any performance or clinician or caregiver completed measures were noted. We hypothesize that either minocycline does not have potential therapeutic effects in ASD or our project was underpowered to define potential subject subgroups who may potentially respond positively to this drug.

Inflammation-induced reorientation of reward versus punishment sensitivity is attenuated by minocycline

BACKGROUND

Inflammation rapidly reorients motivational state, mood is impaired, pleasurable activities avoided and sensitivity to negative stimuli enhanced. When sustained, this can precipitate major depressive episodes. In humans, this has been linked to opposing actions of inflammation on striatal/insula reward/punishment learning signals while in rodents, motivational impairments can be attenuated with minocycline, implicating a mechanistic role for microglia. Here we investigated whether minocycline also inhibits the reorienting effects of lipopolysaccharide (LPS) on reward/punishment sensitivity in humans. Methods Using a crossover design, fifteen healthy volunteers underwent two experimental sessions in which they each received LPS (1 ng/kg) and placebo. Half (N = 8) received minocycline (100 mg bd) and half (N = 7) an identical looking placebo for 3½ days before each session. Six hours post-injection participants completed a probabilistic instrumental learning task in which they had to learn to select high probability reward (win £1) and avoid high probability punishment (lose £1) stimuli to maximise their gains and minimize losses. Physiological and sickness responses were sampled hourly and blood sampled at baseline, 3 and 6 h post-injection. Results LPS induced robust peripheral physiological: temperature, heart rate and immune: differential white cell, IL-6, TNF-α, IL-8, IL-10 responses (all condition × time interactions: p < 0.005), none were significantly modulated by minocycline (p > 0.1). LPS also biased behavior, enhancing punishment compared with reward sensitivity (F(1,13) = 6.10, p = 0.028). Minocycline significantly attenuated this inflammation-induced shift in reward versus punishment sensitivity (F(1,13) = 4.28, p = 0.033). Conclusions These data replicate the previous finding that systemic inflammation rapidly impairs sensitivity to rewards versus punishments in humans and extend this by implicating activated microglia in this acute motivational reorientation with implications for the development of microglial-targeted immune-modulatory therapies in depression.

Effects of early adjunctive pharmacotherapy on serum levels of brain injury biomarkers in patients with traumatic brain injury: a systematic review of randomized controlled studies

Objectives: Traumatic brain injury (TBI) is one of the top causes of morbidity and mortality worldwide. The review aimed to discuss and summarize the current evidence on the effectiveness of adjuvant neuroprotective treatments in terms of their effect on brain injury biomarkers in TBI patients. Methods: To identify relevant studies, four scholarly databases, including PubMed, Cochrane, Scopus, and Google Scholar, were systematically searched using predefined search terms. English-language randomized controlled clinical trials reporting changes in brain injury biomarkers, namely, neuron-specific enolase (NSE), glial fibrillary acid protein (GFAP), ubiquitin carboxyl-terminal esterase L1 (UCHL₁) and/or S100 beta (S100 ß), were included. The methodological quality of the included studies was assessed using the Cochrane risk-of-bias tool. Results: A total of eleven studies with eight different therapeutic options were investigated; of them, tetracyclines, metformin, and memantine were discovered to be promising choices that could improve neurological outcomes in TBI patients. The most utilized serum biomarkers were NSE and S100 ß followed by GFAP, while none of the included studies quantified UCHL₁. The heterogeneity in injury severity categories and measurement timing may affect the overall evaluation of the clinical efficacy of potential therapies. Therefore, unified measurement protocols are highly warranted to inform clinical decisions. Conclusion: Few therapeutic options showed promising results as an adjuvant to standard care in patients with TBI. Several considerations for future work must be directed towards standardizing monitoring biomarkers. Investigating the pharmacotherapy effectiveness using a multimodal biomarker panel is needed. Finally, employing stratified randomization in future clinical trials concerning potential confounders, including age, trauma severity levels, and type, is crucial to inform clinical decisions. Clinical Trial Registration: [https://www.crd.york.ac.uk/prospero/dis], identifier [CRD42022316327].

Targeting Underlying Inflammation in Carcinoma Is Essential for the Resolution of Depressiveness

In modern clinical practice and research on behavioral changes in patients with oncological problems, there are several one-sided approaches to these problems. Strategies for early detection of behavioral changes are considered, but they must take into account the specifics of the localization and phase in the course and treatment of somatic oncological disease. Behavioral changes, in particular, may correlate with systemic proinflammatory changes. In the up-to-date literature, there are a lot of useful pointers on the relationship between carcinoma and inflammation and between depression and inflammation. This review is intended to provide an overview of these similar underlying inflammatory disturbances in both oncological disease and depression. The specificities of acute and chronic inflammation are considered as a basis for causal current and future therapies. Modern therapeutic oncology protocols may also cause transient behavioral changes, so assessment of the quality, quantity, and duration of behavioral symptoms is necessary to prescribe adequate therapy. Conversely, antidepressant properties could be used to ameliorate inflammation. We will attempt to provide some impetus and present some unconventional potential treatment targets related to inflammation. It is certain that only an integrative oncology approach is justifiable in modern patient treatment.

Effect of minocycline and its nano-formulation on central auditory system in blast-induced hearing loss rat model

Blast injuries are common among the military service members and veterans. One of the devastating effects of blast wave induced TBI is either temporary or permanent hearing loss. Treating hearing loss using minocycline is restricted by optimal drug concentration, route of administration, and its half-life. Therefore, therapeutic approach using novel therapeutic delivery method is in great need. Among the different delivery methods, nanotechnology-based drug delivery is desirable, which can achieve longer systemic circulation, pass through some biological barriers and specifically targets desired sites. The current study aimed to examine therapeutic effect of minocycline and its nanoparticle formulation in moderate blast induced hearing loss rat model through central auditory system. The I.v. administered nanoparticle at reduced dose and frequency than regularly administered toxic dose. After moderate blast exposure, rats had hearing impairment as determined by ABR at 7- and 30-days post exposure. In chronic condition, free minocycline also showed the significant reduction in ABR threshold. In central auditory system, it is found in this study that minocycline nanoparticles ameliorate excitation in inferior colliculus; and astrocytes and microglia activation after the blast exposure is reduced by minocycline nanoparticles administration. The study demonstrated that in moderate blast induced hearing loss, minocycline and its nanoparticle formulation exhibited the optimal therapeutic effect on the recovery of the ABR impairment and a protective effect through central auditory system. In conclusion, targeted and non-targeted nanoparticle formulation have therapeutic effect on blast induced hearing loss.

Anti-inflammatory medications for the treatment of mental disorders: A scoping review

This scoping review assessed the effect of anti-inflammatory medications in mental disorders. A search in Medline and the Cochrane database focusing on randomised controlled trials and systematic reviews identified 53 primary research articles, conducted in major depression, bipolar disorder, schizophrenia and somatic symptom disorders and related disorders (SSRD). The findings suggest that there is scope to consider the use of anti-inflammatory agents in mental disorders, however, not as a one-size-fits-all solution. Treatment could be especially helpful in subgroups with evidence of baseline inflammation. Anti-inflammatory medications that seem mostly effective in bipolar disorder or major depressive disorder, such as Celecoxib, Pioglitazone and statins, may differ from the ones with indications of effectiveness in schizophrenia, such as Minocycline and Aspirin. This might suggest a different underlying mechanism for treatment success in those two main illness groups. Further studies with larger sample sizes are needed that take levels of inflammation markers into account.

An Asymmetric Microfluidic/Chitosan Device for Sustained Drug Release in Guided Bone Regeneration Applications

One of the major challenges of guided bone regeneration (GBR) is infections caused by pathogen colonization at wound sites. In this paper, an asymmetric microfluidic/chitosan device was developed to release drugs to inhibit infections and to ensure that guided bone regeneration can be realized. The microfluidic technique was introduced into the GBR membrane for the first time, which demonstrated more controllable drug release, more flexible clinical use and had a lower cost compared with surface treatments and embedded nanoparticles. Based on the theory of diffusion and Fick’s first law, the contact area and concentration gradient were adjusted to realize sustained drug release. The standard deviation of minocycline release over 5 days was only 12.7%, which was lower than the joint effect of porous chitosan discs and nanospheres. The in vitro experiments against E. coli and Streptococcus mutans showed the excellent antibacterial performance of the device (>95%). The in vitro experiments for fibroblasts at the microfluidic side and osteoblasts at the chitosan side showed the satisfactory biocompatibility and the ability of the device to enhance bone regeneration. Therefore, this microfluidic/chitosan device is a promising therapeutic approach to prevent infection and guide bone regeneration.

Traumatic spinal cord injury and the contributions of the post-injury microbiome

Spinal cord injuries are an enormous burden on injured individuals and their caregivers. The pathophysiological effects of injury are not limited to the spine and limb function, but affect numerous body systems. Growing observations in human studies and experimental models suggest that the gut microbiome is altered following spinal cord injury. Given the importance of signals derived from the gut microbiome for host physiology, it is possible that injury-triggered dysbiosis subsequently affects aspects of recovery. Here, we review emerging literature on the role of the microbiome following spinal cord injury. Specifically, we highlight findings from both human and experimental studies that correlate taxonomic changes to aspects of injury recovery. Examination of both observational and emerging interventional studies supports the notion that future therapeutic avenues for spinal cord injury pathologies may lie at the interface of the host and indigenous microbes.

Lipidomics in Understanding Pathophysiology and Pharmacologic Effects in Inflammatory Diseases: Considerations for Drug Development

The lipidome has a broad range of biological and signaling functions, including serving as a structural scaffold for membranes and initiating and resolving inflammation. To investigate the biological activity of phospholipids and their bioactive metabolites, precise analytical techniques are necessary to identify specific lipids and quantify their levels. Simultaneous quantification of a set of lipids can be achieved using high sensitivity mass spectrometry (MS) techniques, whose technological advancements have significantly improved over the last decade. This has unlocked the power of metabolomics/lipidomics allowing the dynamic characterization of metabolic systems. Lipidomics is a subset of metabolomics for multianalyte identification and quantification of endogenous lipids and their metabolites. Lipidomics-based technology has the potential to drive novel biomarker discovery and therapeutic development programs; however, appropriate standards have not been established for the field. Standardization would improve lipidomic analyses and accelerate the development of innovative therapies. This review aims to summarize considerations for lipidomic study designs including instrumentation, sample stabilization, data validation, and data analysis. In addition, this review highlights how lipidomics can be applied to biomarker discovery and drug mechanism dissection in various inflammatory diseases including cardiovascular disease, neurodegeneration, lung disease, and autoimmune disease.

Reconnoitering the transformative journey of minocycline from an antibiotic to an antiepileptic drug

Minocycline, a second-generation tetracycline antibiotic is being widely tested in animals as well as clinical settings for the management of multiple neurological disorders. The drug has shown to exert protective action in a multitude of neurological disorders including spinal-cord injury, stroke, multiple sclerosis, amyotrophic lateral sclerosis, Huntington's disease, and Parkinson's disease. Being highly lipophilic, minocycline easily penetrates the blood brain barrier and is claimed to have excellent oral absorption (~100% bioavailability). Minocycline possesses anti-inflammatory, immunomodulatory, and anti-apoptotic properties, thereby supporting its use in treating neurological disorders. The article henceforth reviews all the recent advances in the transformation of this antibiotic into a potential antiepileptic/antiepileptogenic agent. The article also gives an account of all the clinical trials undertaken till now validating the antiepileptic potential of minocycline. Based on the reported studies, minocycline seems to be an important molecule for treating epilepsy. However, the practical therapeutic implementations of this molecule require extensive mechanism-based in-vitro (cell culture) and in-vivo (animal models) studies followed by its testing in randomized, placebo controlled and double-blind clinical trials in large population as well as in different form of epilepsies.

Challenges of repurposing tetracyclines for the treatment of Alzheimer's and Parkinson's disease

The novel antibiotic-exploiting strategy in the treatment of Alzheimer's (AD) and Parkinson's (PD) disease has emerged as a potential breakthrough in the field. The research in animal AD/PD models provided evidence on the antiamyloidogenic, anti-inflammatory, antioxidant and antiapoptotic activity of tetracyclines, associated with cognitive improvement. The neuroprotective effects of minocycline and doxycycline in animals initiated investigation of their clinical efficacy in AD and PD patients which led to inconclusive results and additionally to insufficient safety data on a long-standing doxycycline and minocycline therapy in these patient populations. The safety issues should be considered in two levels; in AD/PD patients (particularly antibiotic-induced alteration of gut microbiota and its consequences), and as a world-wide threat of development of bacterial resistance to these antibiotics posed by a fact that AD and PD are widespread incurable diseases which require daily administered long-lasting antibiotic therapy. Recently proposed subantimicrobial doxycycline doses should be thoroughly explored for their effectiveness and long-term safety especially in AD/PD populations. Keeping in mind the antibacterial activity-related far-reaching undesirable effects both for the patients and globally, further work on repurposing these drugs for a long-standing therapy of AD/PD should consider the chemically modified tetracycline compounds tailored to lack antimicrobial but retain (or introduce) other activities effective against the AD/PD pathology. This strategy might reduce the risk of long-term therapy-related adverse effects (particularly gut-related ones) and development of bacterial resistance toward the tetracycline antibiotic agents but the therapeutic potential and desirable safety profile of such compounds in AD/PD patients need to be confirmed.

Minocycline Mitigation of Tremor Syndrome and Defect of Cognitive and Balance Induced by Harmaline

Introduction:

Minocycline has anti-inflammatory, anti-apoptotic, and anti-oxidant effects. Preclinical data suggest that minocycline could be beneficial for treating common neurological disorders, including Parkinson disease and multiple sclerosis.

Methods:

In this study, the effects of minocycline on harmaline-induced motor and cognitive impairments were studied in male Wistar rats. The rats were divided into four groups of ten animals each. Harmaline was used for the induction of Essential Tremor (ET). Minocycline (90 mg/kg, IP) was administered 30 minutes before the saline or harmaline. Tremor intensity, spontaneous locomotor activity, passive avoidance memory, anxiety-related behaviors, and motor function were assessed in the rats.

Results:

The results showed that minocycline could recover tremor intensity and step width but failed to recuperate the motor balance. The memory impairments observed in harmaline-treated rats were somewhat reversed by administration of minocycline. The cerebellum and inferior olive nucleus were studied for neuronal degeneration using histochemistry and transmission electron microscopy techniques. Harmaline caused ultrastructural changes and neuronal cell loss in inferior olive and cerebellar Purkinje cells. Minocycline exhibited neuroprotective changes on cerebellar Purkinje cells and inferior olivary neurons.

Conclusion:

These results open new therapeutic perspectives for motor and memory impairments in ET. However, further studies are needed to clarify the exact mechanisms.

Attenuation in Proinflammatory Factors and Reduction in Neuronal Cell Apoptosis and Cerebral Vasospasm by Minocycline during Early Phase after Subarachnoid Hemorrhage in the Rat

Background

Subarachnoid hemorrhage (SAH) is an important subcategory of stroke due to its high mortality rate as well as severe complications such as neurological deficit. It has been suggested that cerebral inflammation is a major factor in advanced brain injury after SAH. Microglia and astrocytes are known supporting cells in the development and maintenance of inflammation in central nervous system. However, the role of microglia and astrocytes in the development of inflammation and neuronal cell apoptosis during the early phase after SAH has not been thoroughly investigated.

Materials and Methods

Sprague-Dawley rats were divided into 4 groups (n = 6/group): sham group, animals subjected to SAH without treatment, SAH animals pretreated with the microglia inhibitor minocycline (50 mg/kg, ip), and SAH animals pretreated with the astrocyte inhibitor fluorocitrate (50 mg/kg, ip). SAH was induced by injecting autologous blood (1 ml/kg) into the cistern magna on day 0. Pretreatment with minocycline or fluorocitrate was given three days prior to the induction of SAH. Rats were sacrificed 6 hr after SAH, and their cerebral spinal fluids were used to measure protein levels of neuroinflammatory cytokines IL-1β, IL-6, and TNF-α by ELISA. In addition, the cerebral cortex was utilized to determine the levels of caspase-3 by western blot and to evaluate neuronal cell apoptosis by immunohistochemistry staining and detect microglia and astrocyte by immunofluorescence staining for Iba-1 and GFAP. In this study, all SAH animals were given an injection of autologous blood and SAH rats treated with minocycline or fluorocitrate received ip injections on day 1, 2, and 3 before inducing SAH. Neurological outcome was assessed by ambulation and placing/stepping reflex responses on day 7.

Results

Immunofluorescence staining showed that SAH induced proliferation of microglia and astrocyte and minocycline inhibited the proliferation of both microglia and astrocyte. However, fluorocitrate inhibited only the proliferation of astrocyte. ELISA analysis showed that SAH upregulated TNF-α and IL-1β, but not IL-6 at 6 hr after SAH. Minocycline, but not fluorocitrate, attenuated the upregulation of TNF-α and IL-1β. Western blot analysis and immunohistochemistry staining showed that SAH induced neuronal cell apoptosis. Pretreatment with minocycline, but not fluorocitrate, decreased SAH-induced neuronal death and cerebral vasospasm. Furthermore, significant improvements in neurobehavioral outcome were seen in the minocycline treatment group, but not in animals treated with fluorocitrate.

Conclusions

Microglia may play an important role to regulate neuronal cell apoptosis and cerebral vasospasm through inhibiting inflammation at an early phase after SAH in the rat.

In vitro synergistic effect of minocycline combined with antifungals against Cryptococcus neoformans

BACKGROUND

Cryptococcus neoformans infections occur in immunocompromised patients, especially those with HIV infection, chemoradiotherapy after cancer, and organ transplantation. Infection can cause pneumonia and meningoencephalitis in severe cases with a high mortality rate if not treated. Although fluconazole and amphotericin B are the first-line treatments for cryptococcosis, the rate of fluconazole resistance has increased significantly due to long-term use. Minocycline is a derivative of tetracycline that exerts its antibacterial effect through inhibition of bacterial protein synthesis. It is also able to pass the blood-brain barrier to act on the central nervous system. The present study investigates the effects of minocycline in combination with antifungals in treating C. neoformans.

OBJECTIVE

To determine in vitro interactions of minocycline combined with itraconazole, voriconazole, posaconazole, fluconazole and amphotericin B against C. neoformans.

METHODS

The minimum inhibitory concentrations (MIC) of the antifungals were determined by the CLSI Clinical and Laboratory Standards Institute M27-A3 microdilution method. The in vitro synergistic effects of minocycline combined with itraconazole, voriconazole, posaconazole, fluconazole, and amphotericin B on C. neoformans were detected by the broth microdilution checkerboard technique and disk diffusion testing.

RESULTS AND CONCLUSION

The working concentration ranges were 0.125-4 µg/mL for itraconazole, 0.03-0.125 µg/ml for voriconazole, 0.03-1 µg/ml for posaconazole, 0.25-16 µg/ml for fluconazole, and 0.125-2 µg/ml for amphotericin B. The synergistic rates of minocycline combinations against C. neoformans were 55% with itraconazole, 10% with voriconazole, 85% with posaconazole, 20% with fluconazole, and 70% with amphotericin B. The effective MIC value of minocycline in the synergistic combination decreased to 2-32 µg/ml, while the MIC of itraconazole decreased to 0.03-0.125 µg/ml, voriconazole 0.03-0.125 µg/ml, posaconazole 0.03-0.125 µg/ml, 0.125-4 µg/ml fluconazole, and 0.06-0.50 µg/ml amphotericin B. The disk diffusion assay showed that the plates containing minocycline and antifungal drugs produced inhibition zones with diameters larger than the single drug plates. Minocycline showed no antagonistic effect in the combinations. In conclusion, the combination of minocycline and azoles or amphotericin B has synergistic effects against C. neoformans in vitro.

Mechanisms Involved in Microglial-Interceded Alzheimer's Disease and Nanocarrier-Based Treatment Approaches

Alzheimer's disease (AD) is a common neurodegenerative disorder accountable for dementia and cognitive dysfunction. The etiology of AD is complex and multifactorial in origin. The formation and deposition of amyloid-beta (Aβ), hyperphosphorylated tau protein, neuroinflammation, persistent oxidative stress, and alteration in signaling pathways have been extensively explored among the various etiological hallmarks. However, more recently, the immunogenic regulation of AD has been identified, and macroglial activation is considered a limiting factor in its etiological cascade. Macroglial activation causes neuroinflammation via modulation of the NLRP3/NF-kB/p38 MAPKs pathway and is also involved in tau pathology via modulation of the GSK-3β/p38 MAPK pathways. Additionally, microglial activation contributes to the discrete release of neurotransmitters and an altered neuronal synaptic plasticity. Therefore, activated microglial cells appear to be an emerging target for managing and treating AD. This review article discussed the pathology of microglial activation in AD and the role of various nanocarrier-based anti-Alzeihmenr's therapeutic approaches that can either reverse or inhibit this activation. Thus, as a targeted drug delivery system, nanocarrier approaches could emerge as a novel means to overcome existing AD therapy limitations.

The immune system and autism spectrum disorder: association and therapeutic challenges

Autism spectrum disorder (ASD) is a neurodevelopmental disorder, affecting communication and behavior. Historically, ASD had been described as a purely psychiatric disorder with genetic factors playing the most critical role. Recently, a growing body of literature has been emphasizing the importance of environmental and immunological factors in its pathogenesis, with the autoimmune process attracting the most attention. This study provides a review of the autoimmune involvement in the pathogenesis of ASD. The\r\nmicrobiome, the representative of the innate immune system in the central nervous system (CNS), plays a critical role in triggering inflammation. Besides, a bidirectional communicational pathway between the CNS and the intestine called the gut‑brain‑axis is linked to the development of ASD. Moreover, the higher plasma level of pro‑inflammatory cytokines in ASD patients and the higher prevalence of autoimmune disorders in the first‑degree family members of affected persons are other clues of the immune system involvement in\r\nthe pathogenesis of ASD. Furthermore, some anti‑inflammatory drugs, including resveratrol and palmitoylethanolamide have shown promising effects by relieving the manifestations of ASD. Although considerable advances have been made in elucidating the role of autoimmunity in the ASD pathogenesis, further studies with stronger methodologies are needed to apply the knowledge to the definitive treatment of ASD.

Successful Use of Minocycline for the Treatment of Methamphetamine-Induced Psychosis and Cognitive Impairments: An Open-Label Case Series

AIM

Methamphetamine-induced psychosis and neuropsychological impairments are common among patients with methamphetamine use disorder. Given some preclinical and clinical studies reporting potential effects of minocycline, a second-generation tetracycline, on correcting manifestations of drug addiction, this study aimed to examine the effectiveness of minocycline in attenuating psychotic symptoms and neuropsychological impairments in chronic methamphetamine users.

METHOD

Five men with treatment-resistant methamphetamine use disorder and psychotic symptoms were selected using a convenience sampling method, and they were administered a daily dose of 200-mg minocycline for 8 weeks; within this period, psychiatric and neuropsychological assessments (including memory and executive functions) were carried out at the baseline, week 2, week 4, week 8, and 2-month follow-up.

RESULTS

The findings showed that minocycline attenuated both positive (Cohen d = 0.63) and negative (Cohen d = 0.53) methamphetamine-induced psychotic symptoms and also improved patients' neuropsychological functions, particularly their auditory working memory (Cohen d = 0.45).

CONCLUSIONS

These results provide promising evidence regarding the positive effects of minocycline as adjunctive pharmacotherapy for patients with methamphetamine use disorder. However, given that this was an open-label study, further research is warranted to draw a firm conclusion about the effectiveness of minocycline for methamphetamine-induced psychosis and neuropsychological deficits.

Inflammation increases the development of depression behaviors in male rats after spinal cord injury

Following spinal cord injury, 18-26% of patients are diagnosed with depressive disorders, compared to 8-12% in the general population. As increased inflammation strongly correlates with depression in both animal and human studies, we hypothesized that the immune activation inherent to SCI could increase depression-like behavior. Thus, we proposed that reducing immune activation with minocycline, a microglial inhibitor, would decrease depression-like behavior following injury. Male Sprague-Dawley rats were given minocycline in their drinking water for 14 days following a moderate, mid-thoracic (T12) spinal contusion. An array of depression-like behaviors (social activity, sucrose preference, forced swim, open field activity) were examined prior to injury as well as on days 9-10, 19-20, and 29-30 post-injury. Peripheral cytokine levels were analyzed in serum collected prior to injury and 10 days post-injury. Hierarchical cluster analysis divided subjects into two groups based on behavior: depressed and not-depressed. Depressed subjects displayed lower levels of open field activity and social interaction relative to their not-depressed counterparts. Depressed subjects also showed significantly greater expression of pro-inflammatory cytokines both before and after injury and displayed lower levels of hippocampal neurogenesis than not-depressed subjects. Intriguingly, subjects who later showed depressive behaviors had higher baseline levels of the pro-inflammatory cytokine IL-6, which persisted throughout the duration of the experiment. Minocycline, however, did not affect serum cytokine levels and did not block the development of depression; equal numbers of minocycline versus vehicle-treated subjects appeared in both phenotypic groups. Despite this, these data overall suggest that molecular correlates of inflammation prior to injury could predict the development of depression after a physical stressor.

Beyond the lesion site: minocycline augments inflammation and anxiety-like behavior following SCI in rats through action on the gut microbiota

Background

Minocycline is a clinically available synthetic tetracycline derivative with anti-inflammatory and antibiotic properties. The majority of studies show that minocycline can reduce tissue damage and improve functional recovery following central nervous system injuries, mainly attributed to the drug’s direct anti-inflammatory, anti-oxidative, and neuroprotective properties. Surprisingly the consequences of minocycline’s antibiotic (i.e., antibacterial) effects on the gut microbiota and systemic immune response after spinal cord injury have largely been ignored despite their links to changes in mental health and immune suppression.

Methods

Here, we sought to determine minocycline’s effect on spinal cord injury-induced changes in the microbiota-immune axis using a cervical contusion injury in female Lewis rats. We investigated a group that received minocycline following spinal cord injury (immediately after injury for 7 days), an untreated spinal cord injury group, an untreated uninjured group, and an uninjured group that received minocycline. Plasma levels of cytokines/chemokines and fecal microbiota composition (using 16s rRNA sequencing) were monitored for 4 weeks following spinal cord injury as measures of the microbiota-immune axis. Additionally, motor recovery and anxiety-like behavior were assessed throughout the study, and microglial activation was analyzed immediately rostral to, caudal to, and at the lesion epicenter.

Results

We found that minocycline had a profound acute effect on the microbiota diversity and composition, which was paralleled by the subsequent normalization of spinal cord injury-induced suppression of cytokines/chemokines. Importantly, gut dysbiosis following spinal cord injury has been linked to the development of anxiety-like behavior, which was also decreased by minocycline. Furthermore, although minocycline attenuated spinal cord injury-induced microglial activation, it did not affect the lesion size or promote measurable motor recovery.

Conclusion

We show that minocycline’s microbiota effects precede its long-term effects on systemic cytokines and chemokines following spinal cord injury. These results provide an exciting new target of minocycline as a therapeutic for central nervous system diseases and injuries.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12974-021-02123-0.

A Review of Systemic Minocycline Side Effects and Topical Minocycline as a Safer Alternative for Treating Acne and Rosacea

Resistance of Cutibacterium acnes to topical antibiotics historically used to treat acne (topical erythromycin and clindamycin and, more recently, topical azithromycin and clarithromycin) has been steadily increasing and new topical antibiotics are needed. Minocycline is a semisynthetic tetracycline-derived antibiotic currently used systemically to treat a wide range of infections caused by Gram-negative and Gram-positive bacteria. In addition to its antibiotic activity, minocycline possesses anti-inflammatory properties, such as the downregulation of proinflammatory cytokine production, suppression of neutrophil chemotaxis, activation of superoxide dismutase, and inhibition of phagocytosis, among others. These characteristics make minocycline a valuable agent for treatment of dermatological diseases such as acne vulgaris and papulopustular rosacea. However, more frequent or serious adverse effects have been observed upon the systemic administration of minocycline than with other tetracyclines. Examples of serious adverse effects include hypersensitivity syndrome reaction, drug-induced lupus, idiopathic intracranial hypertension, and other autoimmune syndromes that may cause death. Here, we review adverse effects and drug–drug interactions observed with oral administration of minocycline and contrast this with topical minocycline formulations recently approved or under development for effectively treating dermatological disorders with fewer adverse effects and less drug interaction.

The Potential Role of Inflammation in Modulating Endogenous Hippocampal Neurogenesis After Spinal Cord Injury

Currently there are approximately 291,000 people suffering from a spinal cord injury (SCI) in the United States. SCI is associated with traumatic changes in mobility and neuralgia, as well as many other long-term chronic health complications, including metabolic disorders, diabetes mellitus, non-alcoholic steatohepatitis, osteoporosis, and elevated inflammatory markers. Due to medical advances, patients with SCI survive much longer than previously. This increase in life expectancy exposes them to novel neurological complications such as memory loss, cognitive decline, depression, and Alzheimer's disease. In fact, these usually age-associated disorders are more prevalent in people living with SCI. A common factor of these disorders is the reduction in hippocampal neurogenesis. Inflammation, which is elevated after SCI, plays a major role in modulating hippocampal neurogenesis. While there is no clear consensus on the mechanism of the decline in hippocampal neurogenesis and cognition after SCI, we will examine in this review how SCI-induced inflammation could modulate hippocampal neurogenesis and provoke age-associated neurological disorders. Thereafter, we will discuss possible therapeutic options which may mitigate the influence of SCI associated complications on hippocampal neurogenesis.

Pharmacologic neuroprotection in ischemic brain injury after cardiac arrest

Cardiac arrest has many implications for morbidity and mortality. Few interventions have been shown to improve return of spontaneous circulation (ROSC) and long-term outcomes after cardiac arrest. Ischemic-reperfusion injury upon achieving ROSC creates an imbalance between oxygen supply and demand. Multiple events occur in the postcardiac arrest period, including excitotoxicity, mitochondrial dysfunction, and oxidative stress and inflammation, all of which contribute to ongoing brain injury and cellular death. Given that complex pathophysiology underlies global brain hypoxic ischemia, neuroprotective strategies targeting multiple stages of the neuropathologic cascade should be considered as a means of mitigating secondary neuronal injury and improving neurologic outcomes and survival in cardiac arrest victims. In this review article, we discuss a number of different pharmacologic agents that may have a potential role in targeting these injurious pathways following cardiac arrest. Pharmacologic therapies most relevant for discussion currently include memantine, perampanel, magnesium, propofol, thiamine, methylene blue, vitamin C, vitamin E, coenzyme Q₁₀ , minocycline, steroids, and aspirin.

Rapamycin, but not minocycline, significantly alters ultrasonic vocalization behavior in C57BL/6J pups in a flurothyl seizure model

Epilepsy is one of the most common neurological disorders, with individuals having an increased susceptibility of seizures in the first few years of life, making children at risk of developing a multitude of cognitive and behavioral comorbidities throughout development. The present study examined the role of PI3K/Akt/mTOR pathway activity and neuroinflammatory signaling in the development of autistic-like behavior following seizures in the neonatal period. Male and female C57BL/6J mice were administered 3 flurothyl seizures on postnatal (PD) 10, followed by administration of minocycline, the mTOR inhibitor rapamycin, or a combined treatment of both therapeutics. On PD12, isolation-induced ultrasonic vocalizations (USVs) of mice were examined to determine the impact of seizures and treatment on communicative behaviors, a component of the autistic-like phenotype. Seizures on PD10 increased the quantity of USVs in female mice and reduced the amount of complex call types emitted in males compared to controls. Inhibition of mTOR with rapamycin significantly reduced the quantity and duration of USVs in both sexes. Changes in USVs were associated with increases in mTOR and astrocyte levels in male mice, however, three PD10 seizures did not result in enhanced proinflammatory cytokine expression in either sex. Beyond inhibition of mTOR activity by rapamycin, both therapeutics did not demonstrate beneficial effects. These findings emphasize the importance of differences that may exist across preclinical seizure models, as three flurothyl seizures did not induce as drastic of changes in mTOR activity or inflammation as observed in other rodent models.

Anti-Inflammatory Therapies for Treatment of Inflammation-Related Preterm Brain Injury

Despite the prevalence of preterm brain injury, there are no established neuroprotective strategies to prevent or alleviate mild-to-moderate inflammation-related brain injury. Perinatal infection and inflammation have been shown to trigger acute neuroinflammation, including proinflammatory cytokine release and gliosis, which are associated with acute and chronic disturbances in brain cell survival and maturation. These findings suggest the hypothesis that the inhibition of peripheral immune responses following infection or nonspecific inflammation may be a therapeutic strategy to reduce the associated brain injury and neurobehavioral deficits. This review provides an overview of the neonatal immunity, neuroinflammation, and mechanisms of inflammation-related brain injury in preterm infants and explores the safety and efficacy of anti-inflammatory agents as potentially neurotherapeutics.

Stroke and immunotherapy: Potential mechanisms and its implications as immune-therapeutics

Ischemia or brain injuries are mostly associated with emergency admissions and huge mortality rates. Stroke is a fatal cerebrovascular malady and second top root of disability and death in both developing and developed countries with a projected rise of 24.9% (from 2010) by 2030. It's the most frequent cause of morbidities and systemic permanent morbidities due to its multi-organ systemic pathology. Brain edema or active immune response cause disturbed or abnormal systemic affects causing inflammatory damage leading to secondary infection and secondary immune response which leads to activation like pneumonia or urine tract infections. There are a variety of post stroke treatments available which claims their usefulness in reducing or inhibiting post stroke and recurrent stroke damage followed by heavy inflammatory actions. Stroke does change the quality of life and also ensures daily chronic rapid neurodegeneration and cognitive decline. The only approved therapies for stroke are alteplase and thrombectomy which is associated with adverse outcomes and are not a total cure for ischemic stroke. Stroke and immune response are reciprocal to the pathology and time of event and it progresses till untreated. The immune reaction during ischemia opens new doors for advanced targeted therapeutics. Nowadays stem cell therapy has shown better results in stroke-prone individuals. Few monoclonal antibodies like natalizumab have shown great impact on pre-clinical and clinical stroke trial studies. In this current review, we have explored an immunology of stroke, current therapeutic scenario and future potential targets as immunotherapeutic agents in stroke therapeutics.

Neuroprotective effect of minocycline against acute brain injury in clinical practice: A systematic review

Acute brain injury is a leading cause of morbidity and mortality worldwide. The term is inclusive of traumatic brain injury, cerebral ischemia, subarachnoid hemorrhage, and intracerebral hemorrhage. Current pharmacologic treatments have had minimal effect on improving neurological outcomes leading to a significant interest in the development neuroprotective agents. Minocycline is a second-generation tetracycline with high blood brain barrier penetrance due to its lipophilic properties. It functions across multiple molecular pathways involved in secondary-injury cascades following acute brain injury. Animal model studies suggest that minocycline might lead to improved neurologic outcomes, but few such trials exist in humans. Clinical investigations have been limited to small randomized trials in ischemic stroke patients which have not demonstrated a clear advantage in neurologic outcomes, but also have not been sufficiently powered to draw definitive conclusions. The potential neuroprotective effect of minocycline in the setting of traumatic brain injury, subarachnoid hemorrhage, and intracerebral hemorrhage have all been limited to pilot studies with phase II/III investigations pending. The authors aim to synthesize what is currently known about minocycline as a neuroprotective agent against acute brain injury in humans.

Neuroinflammation and microglial activation in Alzheimer disease: where do we go from here?

Alzheimer disease (AD) is the most common form of neurodegenerative disease, estimated to contribute 60-70% of all cases of dementia worldwide. According to the prevailing amyloid cascade hypothesis, amyloid-β (Aβ) deposition in the brain is the initiating event in AD, although evidence is accumulating that this hypothesis is insufficient to explain many aspects of AD pathogenesis. The discovery of increased levels of inflammatory markers in patients with AD and the identification of AD risk genes associated with innate immune functions suggest that neuroinflammation has a prominent role in the pathogenesis of AD. In this Review, we discuss the interrelationships between neuroinflammation and amyloid and tau pathologies as well as the effect of neuroinflammation on the disease trajectory in AD. We specifically focus on microglia as major players in neuroinflammation and discuss the spatial and temporal variations in microglial phenotypes that are observed under different conditions. We also consider how these cells could be modulated as a therapeutic strategy for AD.

Synthesis and biological evaluation of a ring analogs of the selective CB2 inverse agonist SMM-189

Microglia are the principle cell type driving sustained neuroinflammation in neurodegenerative diseases such as Alzheimer's, Parkinson's, and Multiple Sclerosis. Interestingly, microglia locked into a chronic M1 pro-inflammatory phenotype significantly up-regulate the cannabinoid receptor 2 (CB2) expression. Our approach to exploiting CB2 as a therapeutic target in neuroinflammatory diseases focuses on the development of selective CB2 inverse agonists to shift microglia bias to a M2 pro-wound healing phenotype. Herein we report work designed to refine the structure activity relationship of the 2,6-dihydroxy-biphenyl-aryl-methanone CB2 inverse agonist scaffold. A series of analogs of our lead compound SMM-189 were synthesized and measured for affinity/selectivity, potency, and efficacy in regulating cAMP production and β-arrestin recruitment. In this series compound 40 demonstrated a significant increase in potency and efficacy for cAMP stimulation compared to SMM-189. Akin to our lead SMM-189, this compound was highly efficacious in biasing microglia to an M2 pro-wound healing phenotype in LPS stimulated cell lines. These results advance our understanding of the structure-activity relationship of the 2,6-dihydroxy-biphenyl-aryl-methanone scaffold and provide further support for regulating microglia activation using CB2 inverse agonists.

Minocycline exhibits synergism with conditioned medium of bone marrow mesenchymal stem cells against ischemic stroke

Several lines of evidence show that a conditioned medium of bone marrow mesenchymal stem cells (BM-MSCcm) improve functional recovery after ischemic stroke but do not reduce ischemic lesions. It is important to develop a treatment strategy that can exhibit a synergistic effect with BM-MSCcm against ischemic stroke. In this study, the effect of BM-MSCcm and/or minocycline was examined in culture and in a middle cerebral artery occlusion (MCAo) animal model. In neuron-glial cultures, BM-MSCcm and combined treatment, but not minocycline, effectively increased neuronal connection and oligodendroglial survival. In contrast, minocycline and combined treatment, but not BM-MSCcm, reduced toxin-induced free radical production in cultures. Either minocycline or BM-MSCcm, or in combination, conferred protective effects against oxygen glucose deprivation-induced cell damage. In an in vivo study, BM-MSCcm and minocycline were administered to rats 2 h after MCAo. Monotherapy with BM-MSCcm or minocycline after ischemic stroke resulted in 9.4% or 17.5% reduction in infarction volume, respectively, but there was no significant difference. Interestingly, there was a 33.9% significant reduction in infarction volume by combined treatment with BM-MSCcm and minocycline in an in vivo study. The combined therapy also significantly improved grasping power, which was not altered by monotherapy. Furthermore, combined therapy increased the expression of neuronal nuclei in the peri-infarct area and hippocampus, and concurrently decreased the expression of ED1 in rat brain and the peri-infarct zone. Our data suggest that minocycline exhibits a synergistic effect with BM-MSCcm against ischemic stroke not only to improve neurological functional outcome but also to reduce cerebral infarction.

Psychosis as an adverse effect of antibiotics

Adverse neuropsychiatric effects of antibiotic medications have been well documented. There is evidence suggesting a direct relationship between acute psychosis and antibiotic exposure. Conversely, the tetracycline antibiotic minocycline has been associated with improvements in psychopathology in patients with psychotic disorders. The purpose of the present study was to investigate the prevalence of spontaneously reported adverse drug reactions (ADRs) of psychotic symptoms in adults for antibiotics and the odds of psychosis compared to minocycline for individual antibiotics and antibiotic classes. We searched the publicly available U.S. F.D.A. Adverse Event Reporting System (FAERS) from inception through March 2020 for which an antibiotic was the suspected agent of an adverse drug reaction (ADR). We investigated 23 different antibiotics, comprising 183,265 adverse event reports and 2955 psychosis ADRs. For individual antibiotics, the prevalence of psychosis ADRs ranged from 0.3 to 3.8%. Fifteen antibiotics were associated with a significantly increased odds of psychosis (OR ​= ​1.67-9.48), including penicillins, fluoroquinolones, macrolides, cephalosporins, and doxycycline. Our results suggest that psychosis is a potential adverse effect of antibiotic treatment, but risks vary by specific agents. Future studies in this area are needed to identify specific underlying biological mechanisms that contribute to these associations. Findings may also inform on clinical decisions regarding the selection of antibiotic therapy in vulnerable patient populations.

Preconditioning Strategies to Enhance Neural Stem Cell-Based Therapy for Ischemic Stroke

Transplantation of neural stem cells (NSCs) has been proposed as an alternative novel therapy to replace damaged neural circuitry after ischemic stroke onset. Nonetheless, albeit the potential of these cells for stroke therapy, many critical challenges are yet to be overcome to reach clinical applications. The major limitation of the NSC-based therapy is its inability to retain most of the donor stem cells after grafting into an ischemic brain area which is lacking of essential oxygen and nutrients for the survival of transplanted cells. Low cell survival rate limits the capacity of NSCs to repair the injured area and this poses a much more difficult challenge to the NSC-based therapy for ischemic stroke. In order to enhance the survival of transplanted cells, several stem cell culture preconditioning strategies have been employed. For ischemic diseases, hypoxic preconditioning is the most commonly applied strategy since the last few decades. Now, the preconditioning strategies have been developed and expanded enormously throughout years of efforts. This review systematically presented studies searched from PubMed, ScienceDirect, Web of Science, Scopus and the Google Scholar database up to 31 March 2020 based on search words containing the following terms: "precondition" or "pretreatment" and "neural stem cell" and "ischemic stroke". The searched data comprehensively reported seven major NSC preconditioning strategies including hypoxic condition, small drug molecules such as minocycline, doxycycline, interleukin-6, adjudin, sodium butyrate and nicorandil, as well as electrical stimulation using conductive polymer for ischemic stroke treatment. We discussed therapeutic benefits gained from these preconditioned NSC for in vitro and in vivo stroke studies and the detailed insights of the mechanisms underlying these preconditioning approaches. Nonetheless, we noticed that there was a scarcity of evidence on the efficacy of these preconditioned NSCs in human clinical studies, therefore, it is still too early to draw a definitive conclusion on the efficacy and safety of this active compound for patient usage. Thus, we suggest for more in-depth clinical investigations of this cell-based therapy to develop into more conscientious and judicious evidence-based therapy for clinical application in the future.

Anti-Inflammatory Diets and Schizophrenia

Schizophrenia is a mental illness characterized by symptoms such as hallucinations, delusions, disorganized speech, disorganized or catatonic behavior, and negative symptoms (emotional flatness, apathy, and lack of speech). It causes social and economic burdens to patients and their family. Although etiology of schizophrenia is still uncertain, dopamine dysregulation is traditionally considered as a main etiological factor of schizophrenia, which has been utilized to develop drugs for treating schizophrenia. Recently, inflammation has presented being a risk factor for schizophrenia in that neuroinflammation contributes to the pathophysiology of schizophrenia and the exacerbation of symptom severity. Various factors including diet can regulate inflammatory state. Specific foods or dietary patterns have anti- or pro-inflammatory potentials. Increased levels of pro-inflammatory cytokines and microglia activation have been reported in schizophrenia populations and were related to the pathogenesis of schizophrenia. Omega-3 fatty acids were often recommended to schizophrenia patients because of their anti-inflammatory activities. In this review, we investigate the inflammation-related pathogenesis of schizophrenia and summarize potential nutritional approaches to inhibit the manifestation of symptoms and to alleviate symptom severity using anti-inflammatory nutrients or functional components.

Modulation of the Microbiome in Parkinson's Disease: Diet, Drug, Stool Transplant, and Beyond

The gastrointestinal microbiome is altered in Parkinson's disease and likely plays a key role in its pathophysiology, affecting symptoms and response to therapy and perhaps modifying progression or even disease initiation. Gut dysbiosis therefore has a significant potential as a therapeutic target in Parkinson's disease, a condition elusive to disease-modifying therapy thus far. The gastrointestinal environment hosts a complex ecology, and efforts to modulate the relative abundance or function of established microorganisms are still in their infancy. Still, these techniques are being rapidly developed and have important implications for our understanding of Parkinson's disease. Currently, modulation of the microbiome can be achieved through non-pharmacologic means such as diet, pharmacologically through probiotic, prebiotic, or antibiotic use and procedurally through fecal transplant. Novel techniques being explored include the use of small molecules or genetically engineered organisms, with vast potential. Here, we review how some of these approaches have been used to date, important areas of ongoing research, and how microbiome modulation may play a role in the clinical management of Parkinson's disease in the future.

Shuxuening injection facilitates neurofunctional recovery via down-regulation of G-CSF-mediated granulocyte adhesion and diapedesis pathway in a subacute stroke mouse model

Post-stroke neural damage is a serious health concern which does not yet have an effective treatment. We have shown previously that Shuxuening injection (SXNI), a Ginkgo biloba extract-based natural medicine, protects brain after an acute ischemic stroke, but its efficacy for post-stroke recovery is not known. This study was to investigate whether SXNI can improve the prognosis of stroke at a subacute phase. Mice with cerebral ischemia-reperfusion injury (CIRI) were established by middle cerebral artery occlusion (MCAO), and drugs or saline were injected by the tail vein every 12 h after reperfusion. The therapeutic effect of SXNI was evaluated by survival rate, modified neurologic severity scores (mNSS), open-field test, locomotive gait patterns, cerebral infarction volume, brain edema and histopathological changes. Subsequently, a combined method of RNA-seq and Ingenuity® Pathway Analysis (IPA) was performed to identify key targets and pathways of SXNI facilitating the prognosis of stroke in mouse brain. The results of the transcriptome analysis were verified by real time reverse transcription-polymerase chain reaction (RT-PCR), enzyme-linked immunosorbent assay (ELISA), western blot (WB) and immunohistochemistry (IHC). The experimental results showed that in the new subacute stroke model, SXNI markedly improves the survival rate, neurological and motor functions and histopathological changes, and significantly reduces cerebral infarction and edema volume. RNA-seq analysis of subacute stroke mice with or without SXNI (3 mL/kg) indicated 963 differentially expressed genes (DEGs) with a fold change ≥ 1.5 and a P-value ≤ 0.01. IPA analysis of DEGs showed that granulocyte adhesion and diapedesis ranked first in the pathway ranking, and the most critical gene regulated by SXNI was G-csf. Simultaneously, RT-PCR, ELISA, WB and IHC results demonstrated that SXNI not only obviously reduced the mRNA expression levels of key genes G-csf, Sele and Mac-1 in this pathway, but also significantly decreased the protein expression levels of G-CSF in serum and E-selectin and MAC-1 in brain tissues. In summary, our research suggested that SXNI can exert a remarkable neurofunctional therapeutic effect on stroke mice via down-regulating G-CSF to inhibit granulocyte adhesion and diapedesis. This study provides experimental evidence that SXNI may fulfill the need for stroke medicine targeting specifically at the recovery stage.

Minocycline protects against acrylamide-induced neurotoxicity and testicular damage in Sprague-Dawley rats

This study investigated the protective effects of minocycline against acrylamide (ACR)-induced neurotoxicity and testicular damage in Sprague-Dawley rats. Forty rats were divided into five groups (eight rats each). Group I received saline (0.5 mL/rat) daily for 10 days and served as the untreated control group. Group II received ACR (30 mg/kg body weight (b.w.)) daily for 10 days. Group III received ACR (30 mg/kg b.w.) daily for 10 days and subsequently minocycline (60 mg/kg b.w.) for five days. Group IV received ACR (30 mg/kg b.w.) daily for 10 days followed by saline for five days and served as the control group for the ACR-minocycline-treated group. Group V received minocycline (60 mg/kg b.w.) for five days. All treatments were administered orally. Rats in group I and V showed normal locomotor behavior and normal histology of the brain and testes. Administration of ACR (Group II and IV) resulted in weight loss and gait abnormalities. Furthermore, neuronal degeneration in the hippocampus and cerebellum and degeneration of the seminiferous tubular epithelium with formation of spermatid giant cells were observed. Ultrastructurally, ACR specifically damaged spermatogonia and spermatocytes. Acrylamide was also seen to cause a significant increase of malondialdehyde levels in the brain and testes. Treatment of ACR-administered rats with minocycline (Group III) significantly alleviated the loss of body weight and improved locomotor function. Minocycline also ameliorated neuronal degeneration and seminiferous tubular damage and decreased malondialdehyde concentrations. In conclusion, minocycline protects against neurotoxic effects of acrylamide and seminiferous tubular damage. Decreasing lipid peroxidation by minocycline might play a role in such protection.