A new avenue for treating neuronal diseases: Ceftriaxone, an old antibiotic demonstrating behavioral neuronal effects

Cognitive Impairment in Parkinson's Disease: An Updated Overview Focusing on Emerging Pharmaceutical Treatment Approaches

Cognitive impairment in patients with Parkinson's disease (PD) is one of the commonest and most disabling non-motor manifestations during the course of the disease. The clinical spectrum of PD-related cognitive impairment includes subjective cognitive decline (SCD), mild cognitive impairment (MCI) and PD dementia (PDD). As the disease progresses, cognitive decline creates a significant burden for the family members and/or caregivers of patients with PD, and has a great impact on quality of life. Current pharmacological treatments have demonstrated partial efficacy and failed to halt disease progression, and novel, effective, and safe therapeutic strategies are required. Accumulating preclinical and clinical evidence shows that several agents may provide beneficial effects on patients with PD and cognitive impairment, including ceftriaxone, ambroxol, intranasal insulin, nilotinib, atomoxetine, mevidalen, blarcamesine, prasinezumab, SYN120, ENT-01, NYX-458, GRF6021, fosgonimeton, INT-777, Neuropeptide S, silibinin, osmotin, cordycepin, huperzine A, fibroblast growth factor 21, Poloxamer 188, ginsenoside Rb1, thioredoxin-1, tangeretin, istradefylline and Eugenia uniflora. Potential underlying mechanisms include the inhibition of a-synuclein aggregation, the improvement of mitochondrial function, the regulation of synaptic plasticity, an impact on the gut-brain axis, the modulation of neuroinflammation and the upregulation of neurotrophic factors, as well as cholinergic, dopaminergic, serotoninergic and norepinephrine neurotransmission. In this updated overview, we aim to cover the clinical aspects of the spectrum of PD-related cognitive impairment and discuss recent evidence on emerging treatment approaches that are under investigation at a preclinical and clinical level. Finally, we aim to provide additional insights and propose new ideas for investigation that may be feasible and effective for the spectrum of PD-related cognitive impairment.

Neurodegenerative and Neurodevelopmental Diseases and the Gut-Brain Axis: The Potential of Therapeutic Targeting of the Microbiome

The human gut microbiome contains the largest number of bacteria in the body and has the potential to greatly influence metabolism, not only locally but also systemically. There is an established link between a healthy, balanced, and diverse microbiome and overall health. When the gut microbiome becomes unbalanced (dysbiosis) through dietary changes, medication use, lifestyle choices, environmental factors, and ageing, this has a profound effect on our health and is linked to many diseases, including lifestyle diseases, metabolic diseases, inflammatory diseases, and neurological diseases. While this link in humans is largely an association of dysbiosis with disease, in animal models, a causative link can be demonstrated. The link between the gut and the brain is particularly important in maintaining brain health, with a strong association between dysbiosis in the gut and neurodegenerative and neurodevelopmental diseases. This link suggests not only that the gut microbiota composition can be used to make an early diagnosis of neurodegenerative and neurodevelopmental diseases but also that modifying the gut microbiome to influence the microbiome-gut-brain axis might present a therapeutic target for diseases that have proved intractable, with the aim of altering the trajectory of neurodegenerative and neurodevelopmental diseases such as Alzheimer's disease, Parkinson's disease, multiple sclerosis, autism spectrum disorder, and attention-deficit hyperactivity disorder, among others. There is also a microbiome-gut-brain link to other potentially reversible neurological diseases, such as migraine, post-operative cognitive dysfunction, and long COVID, which might be considered models of therapy for neurodegenerative disease. The role of traditional methods in altering the microbiome, as well as newer, more novel treatments such as faecal microbiome transplants and photobiomodulation, are discussed.

Ceftriaxone and selenium mitigate seizures and neuronal injury in pentylenetetrazole-kindled rats: Oxidative stress and inflammatory pathway

Epilepsy is one of the most serious worldwide neurological disorders that lead to the cognitive-psychosocial insults in recurrent seizures. About one third of the patients are drug-resistant, so innovative drugs are needed to manage seizures to improve the quality of life. Ceftriaxone is a cephalosporin antibiotic that increases the expression of glutamate transporters-1 and improves the neurobehavioral effects caused by increased glutamate level in the CNS. Selenium is well known antioxidant. The present study aimed to investigate ceftriaxone and selenium therapeutic effects against epilepsy in rats. Epilepsy was induced by PTZ given at a dose (50 mg/kg I.P) on alternative days for 13 days. Eighty rats were randomly divided into 8 groups: Group1-2; normal and vehicle control, Group 3; PTZ group, Group 4-8; kindled rats received selenium, ceftriaxone100, ceftriaxone200, selenium + ceftriaxone100 and selenium + ceftriaxone200 mg/kg/day respectively for a week. At the end of the study, behavioral tests were performed. Oxidative stress, inflammatory markers, neurotransmitters and GLT-1 were measured in brain tissue homogenate. Brain histopathological investigation was also done. PTZ-kindled rats exhibited increased Racine score, besides behavioral tests and histopathological changes, significant elevation in oxidative stress and inflammatory markers, with decrease in serotonin, dopamine, GABA levels and GLT-1 expressions. Selenium and Ceftriaxone alone or combined treatment decreased Racine score with remarkable improvement in behavioral and histopathological changes. The antioxidant enzymes, neurotransmitters and GLT-1 expressions were increased, along with reduced TNF-α, IL-1 levels. Current study showed that selenium + ceftriaxone100 group represents a possible approach to improve epilepsy particularly through inhibiting oxidative stress and inflammation.

Molecular and Cellular Interactions in Pathogenesis of Sporadic Parkinson Disease

An increasing number of the population all around the world suffer from age-associated neurodegenerative diseases including Parkinson’s disease (PD). This disorder presents different signs of genetic, epigenetic and environmental origin, and molecular, cellular and intracellular dysfunction. At the molecular level, α-synuclein (αSyn) was identified as the principal molecule constituting the Lewy bodies (LB). The gut microbiota participates in the pathogenesis of PD and may contribute to the loss of dopaminergic neurons through mitochondrial dysfunction. The most important pathogenetic link is an imbalance of Ca²⁺ ions, which is associated with redox imbalance in the cells and increased generation of reactive oxygen species (ROS). In this review, genetic, epigenetic and environmental factors that cause these disorders and their cause-and-effect relationships are considered. As a constituent of environmental factors, the example of organophosphates (OPs) is also reviewed. The role of endothelial damage in the pathogenesis of PD is discussed, and a ‘triple hit hypothesis’ is proposed as a modification of Braak’s dual hit one. In the absence of effective therapies for neurodegenerative diseases, more and more evidence is emerging about the positive impact of nutritional structure and healthy lifestyle on the state of blood vessels and the risk of developing these diseases.

The Interplay between Gut Microbiota and Parkinson's Disease: Implications on Diagnosis and Treatment

The bidirectional interaction between the gut microbiota (GM) and the Central Nervous System, the so-called gut microbiota brain axis (GMBA), deeply affects brain function and has an important impact on the development of neurodegenerative diseases. In Parkinson’s disease (PD), gastrointestinal symptoms often precede the onset of motor and non-motor manifestations, and alterations in the GM composition accompany disease pathogenesis. Several studies have been conducted to unravel the role of dysbiosis and intestinal permeability in PD onset and progression, but the therapeutic and diagnostic applications of GM modifying approaches remain to be fully elucidated. After a brief introduction on the involvement of GMBA in the disease, we present evidence for GM alterations and leaky gut in PD patients. According to these data, we then review the potential of GM-based signatures to serve as disease biomarkers and we highlight the emerging role of probiotics, prebiotics, antibiotics, dietary interventions, and fecal microbiota transplantation as supportive therapeutic approaches in PD. Finally, we analyze the mutual influence between commonly prescribed PD medications and gut-microbiota, and we offer insights on the involvement also of nasal and oral microbiota in PD pathology, thus providing a comprehensive and up-to-date overview on the role of microbial features in disease diagnosis and treatment.

Diagnostic and therapeutic agents that target alpha-synuclein in Parkinson's disease

The development of disease-modifying drugs and differential diagnostic agents is an urgent medical need in Parkinson’s disease. Despite the complex pathophysiological pathway, the misfolding of alpha-synuclein has been identified as a putative biomarker for detecting the onset and progression of the neurodegeneration associated with Parkinson’s disease. Identifying the most appropriate alpha-synuclein-based diagnostic modality with clinical translation will revolutionize the diagnosis of Parkinson’s. Likewise, molecules that target alpha-synuclein could alter the disease pathway that leads to Parkinson’s and may serve as first-in class therapeutics compared to existing treatment options such as levodopa and dopamine agonist that do not necessarily modify the disease pathway. Notwithstanding the promising benefits that alpha-synuclein presents to therapeutics and diagnostics development for Parkinson’s disease, finding ways to address potential challenges such as inadequate preclinical models, safety and efficacy will be paramount to achieving clinical translation. In this comprehensive review paper, we described the role of alpha-synuclein in the pathogenesis of Parkinson’s disease, as well as how its structure and function relationship delineate disease onset and progression. We further discussed different alpha-synuclein-based diagnostic modalities including biomolecular assays and molecular imaging. Finally, we presented current small molecules and biologics that are being developed as disease-modifying drugs or positron emission tomography imaging probes for Parkinson’s disease.

Ceftriaxone to PRevent pneumOnia and inflammaTion aftEr Cardiac arresT (PROTECT): study protocol for a randomized, placebo-controlled trial

BACKGROUND

Pneumonia is the most common infection after out-of-hospital cardiac arrest (OHCA) occurring in up to 65% of patients who remain comatose after return of spontaneous circulation. Preventing infection after OHCA may (1) reduce exposure to broad-spectrum antibiotics, (2) prevent hemodynamic derangements due to local and systemic inflammation, and (3) prevent infection-associated morbidity and mortality.

METHODS

The ceftriaxone to PRevent pneumOnia and inflammaTion aftEr Cardiac arrest (PROTECT) trial is a randomized, placebo-controlled, single-center, quadruple-blind (patient, treatment team, research team, outcome assessors), non-commercial, superiority trial to be conducted at Maine Medical Center in Portland, Maine, USA. Ceftriaxone 2 g intravenously every 12 h for 3 days will be compared with matching placebo. The primary efficacy outcome is incidence of early-onset pneumonia occurring < 4 days after mechanical ventilation initiation. Concurrently, T cell-mediated inflammation bacterial resistomes will be examined. Safety outcomes include incidence of type-one immediate-type hypersensitivity reactions, gallbladder injury, and Clostridioides difficile-associated diarrhea. The trial will enroll 120 subjects over approximately 3 to 4 years.

DISCUSSION

The PROTECT trial is novel in its (1) inclusion of OHCA survivors regardless of initial heart rhythm, (2) use of a low-risk antibiotic available in the USA that has not previously been tested after OHCA, (3) inclusion of anti-inflammatory effects of ceftriaxone as a novel mechanism for improved clinical outcomes, and (4) complete metagenomic assessment of bacterial resistomes pre- and post-ceftriaxone prophylaxis. The long-term goal is to develop a definitive phase III trial powered for mortality or functional outcome.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04999592 . Registered on August 10, 2021.

The Role of Pathogens and Anti-Infective Agents in Parkinson's Disease, from Etiology to Therapeutic Implications

Parkinson's disease is a debilitating neurodegenerative disorder whose etiology is still unclear, hampering the development of effective treatments. There is an urgent need to identify the etiology and provide further effective treatments. Recently, accumulating evidence has indicated that infection may play a role in the etiology of Parkinson's disease. The infective pathogens may act as a trigger for Parkinson's disease, the most common of which are hepatitis C virus, influenza virus, and Helicobacter pylori. In addition, gut microbiota is increasingly recognized to influence brain function through the gut-brain axis, showing an important role in the pathogenesis of Parkinson's disease. Furthermore, a series of anti-infective agents exhibit surprising neuroprotective effects via various mechanisms, such as interfering with α-synuclein aggregation, inhibiting neuroinflammation, attenuating oxidative stress, and preventing from cell death, independent of their antimicrobial effects. The pleiotropic agents affect important events in the pathogenesis of Parkinson's disease. Moreover, most of them are less toxic, clinically safe and have good blood-brain penetrability, making them hopeful candidates for the treatment of Parkinson's disease. However, the use of antibiotics and subsequent gut dysbiosis may also play a role in Parkinson's disease, making the long-term effects of anti-infective drugs worthy of further consideration and exploration. This review summarizes the current evidence for the association between infective pathogens and Parkinson's disease and subsequently explores the application prospects of anti-infective drugs in Parkinson's disease treatment, providing novel insights into the pathogenesis and treatment of Parkinson's disease.

Neuroprotective Effects of Ceftriaxone Involve the Reduction of Aβ Burden and Neuroinflammatory Response in a Mouse Model of Alzheimer's Disease

Ceftriaxone (CEF) is a safe and multipotent antimicrobial agent that possesses neuroprotective properties. Earlier, we revealed the restoration of cognitive function in OXYS rats with signs of Alzheimer's disease (AD)-like pathology by CEF along with its modulating the expression of genes related to the system of amyloid beta (Aβ) metabolism in the brain. The aim of this study was to determine the effects of CEF on behavior, Aβ deposition, and associated neuroinflammation using another model of an early AD-like pathology induced by Aβ. Mice were injected bilaterally i.c.v. with Aβ fragment 25-35 to produce the AD model, while the CEF treatment (100 mg/kg/day, i.p., 36 days) started the next day after the surgery. The open field test, T-maze, Barnes test, IntelliCage, and passive avoidance test were used for behavioral phenotyping. Neuronal density, amyloid accumulation, and the expression of neuroinflammatory markers were measured in the frontal cortex and hippocampus. CEF exhibited beneficial effects on some cognitive features impaired by Aβ neurotoxicity including complete restoration of the fear-induced memory and learning in the passive avoidance test and improved place learning in the IntelliCage. CEF significantly attenuated amyloid deposition and neuroinflammatory response. Thus, CEF could be positioned as a potent multipurpose drug as it simultaneously targets proteostasis network and neuroinflammation, as well as glutamate excitotoxicity, oxidative pathways, and neurotrophic function as reported earlier. Together with previous reports on the positive effects of CEF in AD models, the results confirm the potential of CEF as a promising treatment against cognitive decline from the early stages of AD progression.

Glutathione Liposomes Carrying Ceftriaxone, FK506, and Nilotinib to Control Overexpressed Dopamine Markers and Apoptotic Factors in Neurons

Advances in liposomal formulation carrying multiple neuroprotective drugs, such as ceftriaxone (CEF), FK506, and nilotinib, can point toward an approach to obviating the difficulties in Parkinson's disease (PD) treatment. We prepared functionalized liposomes decorated with glutathione (GSH) to penetrate the blood-brain barrier (BBB) and cardiolipin (CL) to link up apoptotic neurons. Further, the effect of CEF-FK506-nilotinib-GSH-CL-liposomes on a PD model established by SH-SY5Y cells with 1-methyl-4-phenylpyridinium-induced neurotoxicity was investigated. An increment of the mole percentage of dihexadecyl phosphate and CL increased the particle size and the absolute value of ζ potential, improved the entrapment efficiency of CEF, FK506, and nilotinib, and reduced the drug-releasing rate. The toxicity studies revealed that CEF, FK506, and nilotinib-encapsulated liposomes could enhance the survival of SH-SY5Y cells. Western blot and immunofluorescence revealed that incorporation of CL in a lipid bilayer ameliorated the docking of CEF-FK506-nilotinib-GSH-CL-liposomes at α-synuclein (α-syn), indicating a better targeting capability of the liposomes to degenerated neurons. Treatment with CEF-FK506-nilotinib-GSH-CL-liposomes reduced the expression of Bax and α-syn and promoted the expression of Bcl-2, tyrosine hydroxylase, and the dopamine transporter. GSH- and CL-conjugated liposomes showed combined activity of targeting the BBB and α-syn and augmented the efficiency of the three drugs in rescuing dopaminergic neurons for neurodegenerative therapy.

Treatment effects of the combination of ceftriaxone and valproic acid on neuronal and behavioural functions in a rat model of epilepsy

NEW FINDINGS

What is the central question of this study? Imbalance of activities between GABAergic and glutamatergic systems is involved in epilepsy. It is not known whether simultaneously increasing GABAergic and decreasing glutamatergic activity using valproic acid and ceftriaxone, respectively, leads to better seizure control. What is the central question of this study? Ceftriaxone suppressed seizure and cognitive deficits and restored neuronal density and the number of newborn cells in the hippocampus in a rat model of epilepsy. Combined treatment with ceftriaxone and valproic acid showed additive effects in seizure suppression.

ABSTRACT

The pathophysiology of epilepsy is typically considered as an imbalance between inhibitory GABA and excitatory glutamate neurotransmission. Valproic acid (Val), a GABA agonist, is one of the first-line antiepileptic drugs in the treatment of epilepsy, but it exhibits adverse effects. Ceftriaxone (CEF) elevates expression of glutamate transporter-1, enhances the reuptake of synaptic glutamate, increases the number of newborn cells and exhibits neuroprotective effects in animal studies. In this study, we evaluated effects of the combination of CEF and Val on behavioural and neuronal measures in a rat epilepsy model. Male Wistar rats were injected i.p. with pentylenetetrazol (35 mg/kg, every other day for 13 days) to induce the epilepsy model. Ceftriaxone (10 or 50 mg/kg), Val (50 or 100 mg/kg) or the combination of CEF and Val were injected daily after the fourth pentylenetetrazol injection for seven consecutive days. Epileptic rats exhibited seizure and impairments in motor and cognitive functions. Treatment with CEF and Val reduced the seizure and enhanced motor and cognitive functions in a dose-dependent manner. The combination of CEF (10 mg/kg) and Val (50 mg/kg) improved behaviours considerably. Histologically, compared with control animals, epileptic rats exhibited lower neuronal density and a reduction in hippocampal newborn cells but higher apoptosis in the basolateral amygdala, all of which were restored by the treatment with CEF, Val or the combination of CEF and Val. The study findings demonstrated that the combination of low doses of CEF and Val has beneficial effects on seizure suppression, neuroprotection and improvement in motor and cognitive functions in epilepsy.

Tackling Alzheimer's Disease with Existing Drugs: A Promising Strategy for Bypassing Obstacles

The unmet need for the development of effective drugs to treat Alzheimer 's disease has been steadily growing, representing a major challenge in drug discovery. In this context, drug repurposing, namely the identification of novel therapeutic indications for approved or investigational compounds, can be seen as an attractive attempt to obtain new medications reducing both the time and the economic burden usually required for research and development programs. In the last years, several classes of drugs have evidenced promising beneficial effects in neurodegenerative diseases, and for some of them, preliminary clinical trials have been started. This review aims to illustrate some of the most recent examples of drugs reprofiled for Alzheimer's disease, considering not only the finding of new uses for existing drugs but also the new hypotheses on disease pathogenesis that could promote previously unconsidered therapeutic regimens. Moreover, some examples of structural modifications performed on existing drugs in order to obtain multifunctional compounds will also be described.

MC-100093, a novel β-lactam GLT-1 enhancer devoid of antimicrobial properties attenuates cocaine relapse in rats

Cocaine use disorder (CUD) currently lacks FDA-approved treatments. In rodents, the glutamate transporter-1 (GLT-1) is downregulated in the nucleus accumbens following cocaine self-administration and increasing the expression and function of GLT-1 reduces the reinstatement of cocaine-seeking. The beta-lactam antibiotic ceftriaxone upregulates GLT-1 and attenuates cue- and cocaine-induced cocaine seeking without affecting motivation for natural rewards. While ceftriaxone shows promise for treating CUD, it possesses characteristics that limit successful translation from bench to bedside, including poor brain penetration, a lack of oral bioavailability and a risk of bacterial resistance when used chronically. Thus, we aimed to develop novel molecules that retained the GLT-1 enhancing effects of ceftriaxone but displayed superior drug-like properties. Here we describe a new monocyclic beta-lactam, MC-100093, as a potent up-regulator of GLT-1 that is orally bioavailable and devoid of antimicrobial properties. MC-100093 was synthesized and tested in vitro and in vivo to determine physiochemical, pharmacokinetic and pharmacodynamic properties. Next, adult male rats underwent cocaine self-administration and extinction training. During extinction training, rats received one of four doses of MC-100093 for 6-8 days prior to a single cue-primed reinstatement test. Separate cohorts of rats were used to assess nucleus accumbens GLT-1 expression and MC-100093 effects on sucrose self-administration. We found that 50 mg/kg MC-100093 attenuated cue-primed reinstatement of cocaine-seeking while upregulating GLT-1 expression in the nucleus accumbens core. This dose did not produce sedation, nor did it decrease sucrose consumption or body weight. Thus, MC-100093 represents a potential treatment to reduce cocaine relapse. Significance Statement Increasing GLT-1 activity reliably reduces drug-seeking across classes of drugs, however, existing GLT1-enhancers have side effects and lack oral bioavailability. To address this issue, novel GLT-1 enhancers were synthesized and the compound with the most favorable pharmacokinetic and pharmacodynamic properties, MC-100093, was selected for further testing. MC-100093 attenuated cued cocaine-seeking without reducing food-seeking or locomotion and upregulated GLT-1 expression in the nucleus accumbens.

Gut Microbial Metabolites in Parkinson's Disease: Implications of Mitochondrial Dysfunction in the Pathogenesis and Treatment

The search for therapeutic targets for Parkinson's disease (PD) is hindered by the incomplete understanding of the pathophysiology of the disease. Mitochondrial dysfunction is an area with high potential. The neurobiological signaling connections between the gut microbiome and the central nervous system are incompletely understood. Multiple lines of evidence suggest that the gut microbiota participates in the pathogenesis of PD. Gut microbial dysbiosis may contribute to the loss of dopaminergic neurons through mitochondrial dysfunction. The intervention of gut microbial metabolites via the microbiota-gut-brain axis may serve as a promising therapeutic strategy for PD. In this narrative review, we summarize the potential roles of gut microbial dysbiosis in PD, with emphasis on microbial metabolites and mitochondrial function. We then review the possible ways in which microbial metabolites affect the central nervous system, as well as the impact of microbial metabolites on mitochondrial dysfunction. We finally discuss the possibility of gut microbiota as a therapeutic target for PD.

The study of antiviral drugs targeting SARS-CoV-2 nucleocapsid and spike proteins through large-scale compound repurposing

Contributing to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) clinical treatment, a drug library encompassing approximately 3,142 clinical-stage or FDA-approved small molecules is profiled to identify the candidate therapeutic inhibitors targeting nucleocapsid protein (N) and spike protein (S) of SARS-CoV-2. 16 screened candidates with higher binding affinity are evaluated via virtual screening. Comparing to those under trial/temporarily used antivirus drugs (i.e., umifenovir, lopinavir), ceftriaxone, cefotaxime, and cefuroxime show higher binding affinities to the N-terminal domain of N protein (N-NTD), C-terminal domain of N protein (N-CTD), and receptor-binding domain of S protein (S-RBD). Cefotaxime and cefuroxime have high binding affinities towards S-RBD with angiotensin-converting enzyme 2 (ACE2) complex via influence the critical interface sites at the interface of S-RBD (Arg⁴⁰³, Tyr⁴⁵³, Trp⁴⁹⁵, Gly⁴⁹⁶, Phe⁴⁹⁷, Asn⁵⁰¹and Tyr⁵⁰⁵) and ACE2 (Asn³³, His³⁴, Glu³⁷, Asp³⁸, Lys³⁵³, Ala³⁸⁶, Ala³⁸⁷, Gln³⁸⁸, Pro³⁸⁹, Phe³⁹⁰ and Arg³⁹³) complex.

Selective toxicity of antibacterial agents-still a valid concept or do we miss chances and ignore risks?

BACKGROUND

Selective toxicity antibacteribiotics is considered to be due to interactions with targets either being unique to bacteria or being characterized by a dichotomy between pro- and eukaryotic pathways with high affinities of agents to bacterial- rather than eukaryotic targets. However, the theory of selective toxicity oversimplifies the complex modes of action of antibiotics in pro- and eukaryotes.

METHODS AND OBJECTIVE

This review summarizes data describing multiple modes of action of antibiotics in eukaryotes.

RESULTS

Aminoglycosides, macrolides, oxazolidinones, chloramphenicol, clindamycin, tetracyclines, glycylcyclines, fluoroquinolones, rifampicin, bedaquillin, ß-lactams inhibited mitochondrial translation either due to binding to mitosomes, inhibition of mitochondrial RNA-polymerase-, topoisomerase 2ß-, ATP-synthesis, transporter activities. Oxazolidinones, tetracyclines, vancomycin, ß-lactams, bacitracin, isoniazid, nitroxoline inhibited matrix-metalloproteinases (MMP) due to chelation with zinc and calcium, whereas fluoroquinols fluoroquinolones and chloramphenicol chelated with these cations, too, but increased MMP activities. MMP-inhibition supported clinical efficacies of ß-lactams and daptomycin in skin-infections, and of macrolides, tetracyclines in respiratory-diseases. Chelation may have contributed to neuroprotection by ß-lactams and fluoroquinolones. Aminoglycosides, macrolides, chloramphenicol, oxazolidins oxazolidinones, tetracyclines caused read-through of premature stop codons. Several additional targets for antibiotics in human cells have been identified like interaction of fluoroquinolones with DNA damage repair in eukaryotes, or inhibition of mucin overproduction by oxazolidinones.

CONCLUSION

The effects of antibiotics on eukaryotes are due to identical mechanisms as their antibacterial activities because of structural and functional homologies of pro- and eukaryotic targets, so that the effects of antibiotics on mammals are integral parts of their overall mechanisms of action.

Ceftriaxone Plus Methylprednisolone Combination Therapy Versus Methylprednisolone Monotherapy in Patients With Acute Spinal Cord Injury: A Randomized, Triple-Blind Clinical Trial

BACKGROUND

Guidelines do not suggest the routine use of methylprednisolone (MP) in patients with acute traumatic spinal cord injury (SCI). We tested the hypothesis regarding whether combination therapy with ceftriaxone and MP is superior to MP monotherapy in patients with acute traumatic SCI.

METHODS

In a randomized, triple-blind clinical trial, 60 patients with acute (first 8 hours of the injury) traumatic SCI were enrolled at the Tabriz University of Medical Sciences, Tabriz, Iran, between December 2016 and June 2017. Accordingly, the patients were randomly divided into 2 case and control groups (n = 30 each). Upon admission, all included patients received a bolus dose of MP at 33 mg/kg intravenously (IV) for 15 minutes. Then, after 45 minutes, MP infusion was continued for 24 to 48 hours at a 5.4 mg/kg IV dose. The case group received an additional dose of ceftriaxone at 1 g 2 times a day for 7 days through an IV route. Erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) were checked and compared between case and control groups upon admission and on the fourth and eighth days. Also, sensory and motor functions were evaluated according to the American Spinal Injury Association (ASIA) grading score upon admission, on the third and seventh days, upon discharge and 6 months after admission.

RESULTS

Analyses showed a significant statistical difference between groups in the changes in CRP levels during days 1 and 4 (P = .001) and also during days 4 and 8 (P = .001). However, no significant statistical difference was detected in ESR levels changes between groups during days 1 and 4 (P = .073), and during days 4 and 8 (P = .069). ASIA scale was found to be significantly different between the MP plus ceftriaxone group and MP monotherapy upon admission and 6 months after treatment (P = .001 for both comparisons). However, the number of variations in the ASIA score had no significant statistical difference between groups 6 months after intervention (P = .465).

CONCLUSION

The addition of ceftriaxone to the routine therapeutic protocol of acute SCI is accompanied by improved inflammation markers and functional outcomes 6 months after the intervention.

Ceftriaxone inhibits stress-induced bladder hyperalgesia and alters cerebral micturition and nociceptive circuits in the rat: A multidisciplinary approach to the study of urologic chronic pelvic pain syndrome research network study

AIMS

Emotional stress plays a role in the exacerbation and development of interstitial cystitis/bladder pain syndrome (IC/BPS). Given the significant overlap of brain circuits involved in stress, anxiety, and micturition, and the documented role of glutamate in their regulation, we examined the effects of an increase in glutamate transport on central amplification of stress-induced bladder hyperalgesia, a core feature of IC/BPS.

METHODS

Wistar-Kyoto rats were exposed to water avoidance stress (WAS, 1 hour/day x 10 days) or sham stress, with subgroups receiving daily administration of ceftriaxone (CTX), an activator of glutamate transport. Thereafter, cystometrograms were obtained during bladder infusion with visceromotor responses (VMR) recorded simultaneously. Cerebral blood flow (CBF) mapping was performed by intravenous injection of [¹⁴ C]-iodoantipyrine during passive bladder distension. Regional CBF was quantified in autoradiographs of brain slices and analyzed in three dimensional reconstructed brains with statistical parametric mapping.

RESULTS

WAS elicited visceral hypersensitivity during bladder filling as demonstrated by a decreased pressure threshold and VMR threshold triggering the voiding phase. Brain maps revealed stress effects in regions noted to be responsive to bladder filling. CTX diminished visceral hypersensitivity and attenuated many stress-related cerebral activations within the supraspinal micturition circuit and in overlapping limbic and nociceptive regions, including the posterior midline cortex (posterior cingulate/anterior retrosplenium), somatosensory cortex, and anterior thalamus.

CONCLUSIONS

CTX diminished bladder hyspersensitivity and attenuated regions of the brain that contribute to nociceptive and micturition circuits, show stress effects, and have been reported to demonstrated altered functionality in patients with IC/BPS. Glutamatergic pharmacologic strategies modulating stress-related bladder dysfunction may be a novel approach to the treatment of IC/BPS.

Time to test antibacterial therapy in Alzheimer's disease

Alzheimer's disease is associated with cerebral accumulation of amyloid-β peptide and hyperphosphorylated tau. In the past 28 years, huge efforts have been made in attempting to treat the disease by reducing brain accumulation of amyloid-β in patients with Alzheimer's disease, with no success. While anti-amyloid-β therapies continue to be tested in prodromal patients with Alzheimer's disease and in subjects at risk of developing Alzheimer's disease, there is an urgent need to provide therapeutic support to patients with established Alzheimer's disease for whom current symptomatic treatment (acetylcholinesterase inhibitors and N-methyl d-aspartate antagonist) provide limited help. The possibility of an infectious aetiology for Alzheimer's disease has been repeatedly postulated over the past three decades. Infiltration of the brain by pathogens may act as a trigger or co-factor for Alzheimer's disease, with Herpes simplex virus type 1, Chlamydia pneumoniae, and Porphyromonas gingivalis being most frequently implicated. These pathogens may directly cross a weakened blood-brain barrier, reach the CNS and cause neurological damage by eliciting neuroinflammation. Alternatively, pathogens may cross a weakened intestinal barrier, reach vascular circulation and then cross blood-brain barrier or cause low grade chronic inflammation and subsequent neuroinflammation from the periphery. The gut microbiota comprises a complex community of microorganisms. Increased permeability of the gut and blood-brain barrier induced by microbiota dysbiosis may impact Alzheimer's disease pathogenesis. Inflammatory microorganisms in gut microbiota are associated with peripheral inflammation and brain amyloid-β deposition in subjects with cognitive impairment. Oral microbiota may also influence Alzheimer's disease risk through circulatory or neural access to the brain. At least two possibilities can be envisaged to explain the association of suspected pathogens and Alzheimer's disease. One is that patients with Alzheimer's disease are particularly prone to microbial infections. The other is that microbial infection is a contributing cause of Alzheimer's disease. Therapeutic trials with antivirals and/or antibacterials could resolve this dilemma. Indeed, antiviral agents are being tested in patients with Alzheimer's disease in double-blind placebo-controlled studies. Although combined antibiotic therapy was found to be effective in animal models of Alzheimer's disease, antibacterial drugs are not being widely investigated in patients with Alzheimer's disease. This is because it is not clear which bacterial populations in the gut of patients with Alzheimer's disease are overexpressed and if safe, selective antibacterials are available for them. On the other hand, a bacterial protease inhibitor targeting P. gingivalis toxins is now being tested in patients with Alzheimer's disease. Clinical studies are needed to test if countering bacterial infection may be beneficial in patients with established Alzheimer's disease.

Double deficiency of toll-like receptors 2 and 4 alters long-term neurological sequelae in mice cured of pneumococcal meningitis

Toll-like receptor (TLR) 2 and 4 signalling pathways are central to the body’s defence against invading pathogens during pneumococcal meningitis. Whereas several studies support their importance in innate immunity, thereby preventing host mortality, any role in protecting neurological function during meningeal infection is ill-understood. Here we investigated both the acute immunological reaction and the long-term neurobehavioural consequences of experimental pneumococcal meningitis in mice lacking both TLR2 and TLR4. The absence of these TLRs significantly impaired survival in mice inoculated intracerebroventricularly with Streptococcus pneumoniae. During the acute phase of infection, TLR2/4-deficient mice had lower cerebrospinal fluid concentrations of interleukin-1β, and higher interferon-γ, than their wild-type counterparts. After antibiotic cure, TLR2/4 double deficiency was associated with aggravation of behavioural impairment in mice, as shown by diurnal hypolocomotion throughout the adaptation phases in the Intellicage of TLR-deficient mice compared to their wild-type counterparts. While TLR2/4 double deficiency did not affect the cognitive ability of mice in a patrolling task, it aggravated the impairment of cognitive flexibility. We conclude that TLR2 and TLR4 are central to regulating the host inflammatory response in pneumococcal meningitis, which may mediate diverse compensatory mechanisms that protect the host not only against mortality but also long-term neurological complications.