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

Novel Collagen Membrane Formulations with Irinotecan or Minocycline for Potential Application in Brain Cancer

Our study explores the development of collagen membranes with integrated minocycline or irinotecan, targeting applications in tissue engineering and drug delivery systems. Type I collagen, extracted from bovine skin using advanced fibril-forming technology, was crosslinked with glutaraldehyde to create membranes. These membranes incorporated minocycline, an antibiotic, or irinotecan, a chemotherapeutic agent, in various concentrations. The membranes, varying in drug concentration, were studied by water absorption and enzymatic degradation tests, demonstrating a degree of permeability. We emphasize the advantages of local drug delivery for treating high-grade gliomas, highlighting the targeted approach's efficacy in reducing systemic adverse effects and enhancing drug bioavailability at the tumor site. The utilization of collagen membranes is proposed as a viable method for local drug delivery. Irinotecan's mechanism, a topoisomerase I inhibitor, and minocycline's broad antibacterial spectrum and inhibition of glial cell-induced membrane degradation are discussed. We critically examine the challenges posed by the systemic administration of chemotherapeutic agents, mainly due to the blood-brain barrier's restrictive nature, advocating for local delivery methods as a more effective alternative for glioblastoma treatment. These local delivery strategies, including collagen membranes, are posited as significant advancements in enhancing therapeutic outcomes for glioblastoma patients.

Beyond nimodipine: advanced neuroprotection strategies for aneurysmal subarachnoid hemorrhage vasospasm and delayed cerebral ischemia

The clinical management of aneurysmal subarachnoid hemorrhage (SAH)-associated vasospasm remains a challenge in neurosurgical practice, with its prevention and treatment having a major impact on neurological outcome. While considered a mainstay, nimodipine is burdened by some non-negligible limitations that make it still a suboptimal candidate of pharmacotherapy for SAH. This narrative review aims to provide an update on the pharmacodynamics, pharmacokinetics, overall evidence, and strength of recommendation of nimodipine alternative drugs for aneurysmal SAH-associated vasospasm and delayed cerebral ischemia. A PRISMA literature search was performed in the PubMed/Medline, Web of Science, ClinicalTrials.gov, and PubChem databases using a combination of the MeSH terms "medical therapy," "management," "cerebral vasospasm," "subarachnoid hemorrhage," and "delayed cerebral ischemia." Collected articles were reviewed for typology and relevance prior to final inclusion. A total of 346 articles were initially collected. The identification, screening, eligibility, and inclusion process resulted in the selection of 59 studies. Nicardipine and cilostazol, which have longer half-lives than nimodipine, had robust evidence of efficacy and safety. Eicosapentaenoic acid, dapsone and clazosentan showed a good balance between effectiveness and favorable pharmacokinetics. Combinations between different drug classes have been studied to a very limited extent. Nicardipine, cilostazol, Rho-kinase inhibitors, and clazosentan proved their better pharmacokinetic profiles compared with nimodipine without prejudice with effective and safe neuroprotective role. However, the number of trials conducted is significantly lower than for nimodipine. Aneurysmal SAH-associated vasospasm remains an area of ongoing preclinical and clinical research where the search for new drugs or associations is critical.

Immune-mediated disruption of the blood-brain barrier after intracerebral hemorrhage: Insights and potential therapeutic targets

AIMS

Intracerebral hemorrhage (ICH) is a condition that arises due to the rupture of cerebral blood vessels, leading to the flow of blood into the brain tissue. One of the pathological alterations that occurs during an acute ICH is an impairment of the blood-brain barrier (BBB), which leads to severe perihematomal edema and an immune response.

DISCUSSION

A complex interplay between the cells of the BBB, for example, pericytes, astrocytes, and brain endothelial cells, with resident and infiltrating immune cells, such as microglia, monocytes, neutrophils, T lymphocytes, and others accounts for both damaging and protective mechanisms at the BBB following ICH. However, the precise immunological influence of BBB disruption has yet to be richly ascertained, especially at various stages of ICH.

CONCLUSION

This review summarizes the changes in different cell types and molecular components of the BBB associated with immune-inflammatory responses during ICH. Furthermore, it highlights promising immunoregulatory therapies to protect the integrity of the BBB after ICH. By offering a comprehensive understanding of the mechanisms behind BBB damage linked to cellular and molecular immunoinflammatory responses after ICH, this article aimed to accelerate the identification of potential therapeutic targets and expedite further translational research.

Promising immunomodulators for management of substance and alcohol use disorders

INTRODUCTION

The neuroimmune system has emerged as a novel target for the treatment of substance use disorders (SUDs), with immunomodulation producing encouraging therapeutic benefits in both preclinical and clinical settings.

AREAS COVERED

In this review, we describe the mechanism of action and immune response to methamphetamine, opioids, cocaine, and alcohol. We then discuss off-label use of immunomodulators as adjunctive therapeutics in the treatment of neuropsychiatric disorders, demonstrating their potential efficacy in affective and behavioral disorders. We then discuss in detail the mechanism of action and recent findings regarding the use of ibudilast, minocycline, probenecid, dexmedetomidine, pioglitazone, and cannabidiol to treat (SUDs). These immunomodulators are currently being investigated in clinical trials described herein, specifically for their potential to decrease substance use, withdrawal severity, central and peripheral inflammation, comorbid neuropsychiatric disorder symptomology, as well as their ability to improve cognitive outcomes.

EXPERT OPINION

We argue that although mixed, findings from recent preclinical and clinical studies underscore the potential benefit of immunomodulation in the treatment of the behavioral, cognitive, and inflammatory processes that underlie compulsive substance use.

Minocycline as a prospective therapeutic agent for cancer and non-cancer diseases: a scoping review

Minocycline is an FDA-approved secondary-generation tetracycline antibiotic. It is a synthetic antibiotic having many biological effects, such as antioxidant, anti-inflammatory, anti-cancer, and neuroprotective functions. This study discusses the pharmacological mechanisms of preventive and therapeutic effects of minocycline. Specifically, it provides a comprehensive overview of the molecular pathways by which minocycline acts on the different cancers, including ovarian, breast, glioma, colorectal, liver, pancreatic, lung, prostate, melanoma, head and neck, leukemia, and non-cancer diseases such as Alzheimer's disease, Parkinson, schizophrenia, multiple sclerosis, Huntington, polycystic ovary syndrome, and coronavirus disease 19. Minocycline may be a potential medication for these disorders due to its strong blood-brain barrier penetrance. It is also widely accepted as a specific medication, has a well-known side-effect characteristic, is reasonably priced, making it appropriate for continuous use in managing diseases, and has been demonstrated as an oral approach because it is effectively absorbed and accomplished almost all of the body's parts.

Minocycline induced apoptosis and suppressed expression of matrix metalloproteinases 2 and 9 in the breast cancer MCF-7 cells

BACKGROUND

In women, breast cancer is the second most frequent type of cancer. Looking for new and effective cancer-specific therapies with little to no adverse effects on healthy cells is critical.

OBJECTIVE

Minocycline, a second-generation tetracycline, has shown anticancer effects by targeting multiple pathways in various cancers. This study aimed to determine minocycline effects on the cell proliferation, apoptosis, and invasion of the human MCF-7 cells.

METHODS

MTT assay was used to evaluate the cytotoxicity of minocycline on the cells. Flow cytometry was performed to investigate the induction of apoptosis and the cell cycle progression. The expression levels of apoptotic and migration proteins and genes were assessed by western blotting and qRT-PCR. The scratch test was performed to evaluate the anti-migration effect of the drug.

RESULTS

The results indicated that the IC50 value of minocycline for MCF-7 cells was 36.10 µM. Minocycline treatment caused sub-G1 cell accumulation, indicating a significant apoptotic effect on the MCF-7 cells. Annexin-V/PI staining revealed a significant rise in early and late apoptotic cell percentages. Minocycline up-regulated Bax and Caspase-3 expression and down-regulated Bcl-2 and Pro-Cas3. The scratch test revealed significant anti-migration effects for minocycline. Furthermore, it caused down-regulation of MMP-2 and MMP-9 in a concentration-dependent method.

CONCLUSION

These findings further confirmed the anticancer effect of minocycline and highlighted that minocycline maybe considered as potential therapeutic agent for breast cancer treatment.

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.

Mobilization of the innate immune response by a specific immunostimulant β-glucan confers resistance to chronic stress-induced depression-like behavior by preventing neuroinflammatory responses

Pre-stimulation of the innate immune response is an effective strategy to prevent depression-like phenotypes in animals. However, the use of conventional immunostimulants may cause adverse effects. Therefore, the search for agents that stimulate the innate immune response but do not induce a pro-inflammatory response could be a new research direction for the prevention of depression. β-glucan is a polysaccharide from Saccharomyces cerevisiae with unique immunomodulatory activity in microglia without eliciting a pro-inflammatory response that could lead to tissue damage. This suggests that β-glucan may be a suitable drug that can be used to prevent depression-like phenotypes. Our results showed that a single injection of β-glucan 1 day before stress exposure at a dose of 10 or 20 mg/kg, but notat a dose of 5 mg/kg, prevented depression-like behavior in mice treated with chronic unpredictable stress (CUS). This effect of β-glucan disappeared when the time interval between β-glucan and stress was extended from 1 day or 5 days to 10 days, which was rescued by a second injection 10 days after the first injection or by a repeated injection (4×, once daily) 10 days before stress exposure. A single β-glucan injection (20 mg/kg) 1 day before stress exposure prevented the CUS-induced increase in brain pro-inflammatory cytokines, and inhibition of the innate immune response by minocycline (40 mg/kg) abolished the preventive effect of β-glucan on CUS-induced depression-like behaviors and neuroinflammatory responses. These results suggest that β-glucan may prevent chronic stress-induced depression-like phenotypes and neuroinflammatory responses by stimulating the innate immune response.

The management of severe traumatic brain injury in the initial postinjury hours - current evidence and controversies

PURPOSE OF REVIEW

To provide an overview of recent studies discussing novel strategies, controversies, and challenges in the management of severe traumatic brain injury (sTBI) in the initial postinjury hours.

RECENT FINDINGS

Prehospital management of sTBI should adhere to Advanced Trauma Life Support (ATLS) principles. Maintaining oxygen saturation and blood pressure within target ranges on-scene by anesthetist, emergency physician or trained paramedics has resulted in improved outcomes. Emergency department (ED) management prioritizes airway control, stable blood pressure, spinal immobilization, and correction of impaired coagulation. Noninvasive techniques such as optic nerve sheath diameter measurement, pupillometry, and transcranial Doppler may aid in detecting intracranial hypertension. Osmotherapy and hyperventilation are effective as temporary measures to reduce intracranial pressure (ICP). Emergent computed tomography (CT) findings guide surgical interventions such as decompressive craniectomy, or evacuation of mass lesions. There are no neuroprotective drugs with proven clinical benefit, and steroids and hypothermia cannot be recommended due to adverse effects in randomized controlled trials.

SUMMARY

Advancement of the prehospital and ED care that include stabilization of physiological parameters, rapid correction of impaired coagulation, noninvasive techniques to identify raised ICP, emergent surgical evacuation of mass lesions and/or decompressive craniectomy, and temporary measures to counteract increased ICP play pivotal roles in the initial management of sTBI. Individualized approaches considering the underlying pathology are crucial for accurate outcome prediction.

Treatment of Stroke at a Delayed Timepoint with a Repurposed Drug Targeting Sigma 1 Receptors

Sigma 1 receptors are intracellular chaperone proteins that have been explored as a subacute treatment to enhance post-stroke recovery. We recently identified the antitussive oxeladin as a selective sigma 1 receptor agonist with the ability to stimulate the release of brain-derived neurotrophic factor from neurons in vitro. In this study, we hypothesized that oral oxeladin citrate would stimulate BDNF secretion and improve stroke outcomes when administered to male rats starting 48 h after transient middle cerebral artery occlusion. Oxeladin did not alter blood clotting and crossed the blood brain barrier within 30 min of oral administration. Rats underwent 90 min of transient middle cerebral artery occlusion. Forty-eight hours later rats began receiving daily oxeladin (135 mg/kg) for 11 days. Oxeladin significantly improved neurological function on days 3, 7, and 14 following MCAO. Infarct size was not altered by a single dose, but the final extent of infarct after 14 days was decreased. However, there was no significant reduction in astrogliosis or microgliosis compared to vehicle-treated control rats. In agreement with in vitro studies, oxeladin increased the amount of mature BDNF in the cerebral cortex 2, 6, and 24 h after single oral dose. However, the increase in BDNF did not result in increases in cellular proliferation in the subventricular zone or dentate gyrus when compared to vehicle-treated controls. These results suggest that oxeladin may reduce the extent of infarct expansion in the subacute phase of stroke, although this action does not appear to involve a reduction in inflammation or increased cell proliferation.

Neurotoxic properties of the Zika virus envelope protein

Prenatal Zika virus (ZIKV) infection is a serious global concern as it can lead to brain injury and many serious birth defects, collectively known as congenital Zika syndrome. Brain injury likely results from viral mediated toxicity in neural progenitor cells. Additionally, postnatal ZIKV infections have been linked to neurological complications, yet the mechanisms driving these manifestations are not well understood. Existing data suggest that the ZIKV envelope protein can persist in the central nervous system for extended periods of time, but it is unknown if this protein can independently contribute to neuronal toxicity. Here we find that the ZIKV envelope protein is neurotoxic, leading to overexpression of poly adenosine diphosphate -ribose polymerase 1, which can induce parthanatos. Together, these data suggest that neuronal toxicity resulting from the envelope protein may contribute to the pathogenesis of post-natal ZIKV-related neurologic complications.

Minocycline as Treatment for Psychiatric and Neurological Conditions: A Systematic Review and Meta-Analysis

Minocycline has anti-inflammatory, antioxidant, and anti-apoptotic properties that explain the renewed interest in its use as an adjunctive treatment for psychiatric and neurological conditions. Following the completion of several new clinical trials using minocycline, we proposed an up-to-date systematic review and meta-analysis of the data available. The PICO (patient/population, intervention, comparison and outcomes) framework was used to search 5 databases aiming to identify randomized controlled trials that used minocycline as an adjunctive treatment for psychiatric and neurological conditions. Search results, data extraction, and risk of bias were performed by two independent authors for each publication. Quantitative meta-analysis was performed using RevMan software. Literature search and review resulted in 32 studies being included in this review: 10 in schizophrenia, 3 studies in depression, and 7 in stroke, with the benefit of minocycline being used in some of the core symptoms evaluated; 2 in bipolar disorder and 2 in substance use, without demonstrating a benefit for using minocycline; 1 in obsessive-compulsive disorder, 2 in brain and spinal injuries, 2 in amyotrophic lateral sclerosis, 1 in Alzheimer’s disease, 1 in multiple systems atrophy, and 1 in pain, with mixes results. For most of the conditions included in this review the data is still limited and difficult to interpret, warranting more well-designed and powered studies. On the other hand, the studies available for schizophrenia seem to suggest an overall benefit favoring the use of minocycline as an adjunctive treatment.

Hypothesized neuroprotective effect of minocycline against COVID-19-induced stroke and neurological dysfunction: possible role of matrix metalloprotease signaling pathway

Severe Acute Respiratory Syndrome Coronavirus-2 (COVID-19) is a respiratory disease that causes dysfunction in respiration. Since late 2019, this virus has infected and killed millions of people around the world and imposed many medical and therapeutic problems in the form of a pandemic. According to recent data, COVID-19 disease can increase the risk of stroke, which can be deadly or cause many neurological disorders after the disease. During the last two years, many efforts have been made to introduce new therapies for management of COVID-19-related complications, including stroke. To achieve this goal, several conventional drugs have been investigated for their possible therapeutic roles. Minocycline, a broad-spectrum, long-acting antibiotic with anti-inflammatory and antioxidant properties, is one such conventional drug that should be considered for treating COVID-19-related stroke, as indirect evidence indicates that it exerts neuroprotective effects, can modulate stroke occurrence, and can play an effective and strategic role in management of the molecular signals caused by stroke and its destructive consequences. The matrix metalloprotease (MMP) signaling pathway is one of the main signaling pathways involved in the occurrence and exacerbation of stroke; however, its role in COVID-19-induced stroke and the possible role of minocycline in the management of this signaling pathway in patients with COVID-19 is unclear and requires further investigation. Based on this concept, we hypothesize that minocycline might act via MMP signaling as a neuroprotective agent against COVID-19-induced neurological dysfunction, particularly stroke.

Effects of TRAM-34 and minocycline on neuroinflammation caused by diabetic ketoacidosis in a rat model

INTRODUCTION

Diabetic ketoacidosis (DKA) causes acute and chronic neuroinflammation that may contribute to cognitive decline in patients with type 1 diabetes. We evaluated the effects of agents that reduce neuroinflammation (triarylmethane-34 (TRAM-34) and minocycline) during and after DKA in a rat model.

RESEARCH DESIGN AND METHODS

Juvenile rats with DKA were treated with insulin and saline, either alone or in combination with TRAM-34 (40 mg/kg intraperitoneally twice daily for 3 days, then daily for 4 days) or minocycline (45 mg/kg intraperitoneally daily for 7 days). We compared cytokine and chemokine concentrations in brain tissue lysates during DKA among the three treatment groups and in normal controls and diabetic controls (n=9-15/group). We also compared brain inflammatory mediator levels in these same groups in adult diabetic rats that were treated for DKA as juveniles.

RESULTS

Brain tissue concentrations of chemokine (C-C) motif ligand (CCL)3, CCL5 and interferon (IFNγ) were increased during acute DKA, as were brain cytokine composite scores. Both treatments reduced brain inflammatory mediator levels during acute DKA. TRAM-34 predominantly reduced chemokine concentrations (chemokine (C-X-C) motif ligand (CXCL-1), CCL5) whereas minocycline had broader effects, (reducing CXCL-1, tumor necrosis factor (TNFα), IFNγ, interleukin (IL) 2, IL-10 and IL-17A). Brain inflammatory mediator levels were elevated in adult rats that had DKA as juveniles, compared with adult diabetic rats without previous DKA, however, neither TRAM-34 nor minocycline treatment reduced these levels.

CONCLUSIONS

These data demonstrate that both TRAM-34 and minocycline reduce acute neuroinflammation during DKA, however, treatment with these agents for 1 week after DKA does not reduce long-term neuroinflammation.

Revisiting Minocycline in Intracerebral Hemorrhage: Mechanisms and Clinical Translation

Intracerebral hemorrhage (ICH) is an important subtype of stroke with an unsatisfactory prognosis of high mortality and disability. Although many pre-clinical studies and clinical trials have been performed in the past decades, effective therapy that meaningfully improve prognosis and outcomes of ICH patients is still lacking. An active area of research is towards alleviating secondary brain injury after ICH through neuroprotective pharmaceuticals and in which minocycline is a promising candidate. Here, we will first discuss new insights into the protective mechanisms of minocycline for ICH including reducing iron-related toxicity, maintenance of blood-brain barrier, and alleviating different types of cell death from preclinical data, then consider its shortcomings. Finally, we will review clinical trial perspectives for minocycline in ICH. We hope that this summary and discussion about updated information on minocycline as a viable treatment for ICH can facilitate further investigations.

Acute minocycline administration reduces brain injury and improves long-term functional outcomes after delayed hypoxemia following traumatic brain injury

Clinical trials of therapeutics for traumatic brain injury (TBI) demonstrating preclinical efficacy for TBI have failed to replicate these results in humans, in part due to the absence of clinically feasible therapeutic windows for administration. Minocycline, an inhibitor of microglial activation, has been shown to be neuroprotective when administered early after experimental TBI but detrimental when administered chronically to human TBI survivors. Rather than focusing on the rescue of primary injury with early administration of therapeutics which may not be clinically feasible, we hypothesized that minocycline administered at a clinically feasible time point (24 h after injury) would be neuroprotective in a model of TBI plus delayed hypoxemia. We first explored several different regimens of minocycline dosing with the initial dose 24 h after injury and 2 h prior to hypoxemia, utilizing short-term neuropathology to select the most promising candidate. We found that a short course of minocycline reduced acute microglial activation, monocyte infiltration and hippocampal neuronal loss at 1 week post injury. We then conducted a preclinical trial to assess the long-term efficacy of a short course of minocycline finding reductions in hippocampal neurodegeneration and synapse loss, preservation of white matter myelination, and improvements in fear memory performance at 6 months after injury. Timing in relation to injury and duration of minocycline treatment and its impact on neuroinflammatory response may be responsible for extensive neuroprotection observed in our studies.

Cerebral ischemic stroke and different approaches for treatment of stroke

Background

Cerebral ischemia can be considered a lethal disease as it is a leading cause of death worldwide with no prompt line of treatment. The factors which make this disease more fatal are failure of drugs while crossing BBB, very low availability of the drug in the brain, inefficiency of drug molecule in the clinical studies, limited availability of clinical data, lack of awareness about this disease, and many more.

Main body

This review focuses on reasons and mechanisms of stroke, classification of brain ischemia; it also reveals the current scenario of stroke in India. Very few drugs are effective for the treatment of stroke. This compilation furnishes conventional and recent treatments of stroke along with their hurdles like the gap between preclinical and clinical studies. This review also suggests effective routes of administration of drugs for the treatment of brain ischemia specifically nose-to-brain route and effectiveness of different dosage forms precisely nanoformulations, as the most effective dosage form.

Conclusion

By following different guidelines and treatments, the risk of brain ischemia can be minimized as well as some advanced techniques for the treatment of this disease proving their efficiency. One of the important aspects in the success of the treatment for this disease is the route of administration of the drug. Among all routes, intranasal drug delivery presents a potential approach and is supposed to be the next-generation therapy for brain disorders. The nose-to-brain route is very effective, and it shows some promising results in case of stroke treatment. The strategy is still under investigation despite various successful lab-scale studies; there are numerous challenges to reach the product in the market. Research is going on to get a better understanding of this strategy. We believe that detailed studies to resolve pitfalls will lead to the successful development of an intranasal formulation for the management of ischemic brain injury such as stroke.