Enhanced Neuroprotective Effects of Combination Therapy with Bone Marrow-Derived Mesenchymal Stem Cells and Ginkgo biloba Extract (EGb761) in a Rat Model of Experimental Autoimmune Encephalomyelitis

Hydrogel-based approaches to target hypersensitivity mechanisms underlying autoimmune disease

A robust adaptive immune response is essential for combatting pathogens. In the wrong context such as due to genetic and environmental factors, however, the same mechanisms crucial for self-preservation can lead to a loss of self-tolerance. Resulting autoimmunity manifests in the development of a host of organ-specific or systemic autoimmune diseases, hallmarked by aberrant immune responses and tissue damage. The prevalence of autoimmune diseases is on the rise, medical management of which focuses primarily on pharmacological immunosuppression that places patients at a risk of side effects, including opportunistic infections and tumorigenesis. Biomaterial-based drug delivery systems confer many opportunities to address challenges associated with conventional disease management. Hydrogels, in particular, can protect encapsulated cargo (drug or cell therapeutics) from the host environment, afford their presentation in a controlled manner, and can be tailored to respond to disease conditions or support treatment via multiplexed functionality. Moreover, localized delivery to affected sites by these approaches has the potential to concentrate drug action at the site, reduce off-target exposure, and enhance patient compliance by reducing the need for frequent administration. Despite their many benefits for the management of autoimmune disease, such biomaterial-based approaches focus largely on the downstream effects of hypersensitivity mechanisms and have a limited capacity to eradicate the disease. In contrast, direct targeting of mechanisms of hypersensitivity reactions uniquely enables prophylaxis or the arrest of disease progression by mitigating the basis of autoimmunity. One promising approach is to induce self-antigen-specific tolerance, which specifically subdues damaging autoreactivity while otherwise retaining the normal immune responses. In this review, we will discuss hydrogel-based systems for the treatment of autoimmune disease, with a focus on those that target hypersensitivity mechanisms head-on. As the field continues to advance, it will expand the range of therapeutic choices for people coping with autoimmune diseases, providing fresh prospects for better clinical outcomes and improved quality of life.

Ginkgo Biloba and Long COVID: In Vivo and In Vitro Models for the Evaluation of Nanotherapeutic Efficacy

Coronavirus infections are neuroinvasive and can provoke injury to the central nervous system (CNS) and long-term illness consequences. They may be associated with inflammatory processes due to cellular oxidative stress and an imbalanced antioxidant system. The ability of phytochemicals with antioxidant and anti-inflammatory activities, such as Ginkgo biloba, to alleviate neurological complications and brain tissue damage has attracted strong ongoing interest in the neurotherapeutic management of long COVID. Ginkgo biloba leaf extract (EGb) contains several bioactive ingredients, e.g., bilobalide, quercetin, ginkgolides A-C, kaempferol, isorhamnetin, and luteolin. They have various pharmacological and medicinal effects, including memory and cognitive improvement. Ginkgo biloba, through its anti-apoptotic, antioxidant, and anti-inflammatory activities, impacts cognitive function and other illness conditions like those in long COVID. While preclinical research on the antioxidant therapies for neuroprotection has shown promising results, clinical translation remains slow due to several challenges (e.g., low drug bioavailability, limited half-life, instability, restricted delivery to target tissues, and poor antioxidant capacity). This review emphasizes the advantages of nanotherapies using nanoparticle drug delivery approaches to overcome these challenges. Various experimental techniques shed light on the molecular mechanisms underlying the oxidative stress response in the nervous system and help comprehend the pathophysiology of the neurological sequelae of SARS-CoV-2 infection. To develop novel therapeutic agents and drug delivery systems, several methods for mimicking oxidative stress conditions have been used (e.g., lipid peroxidation products, mitochondrial respiratory chain inhibitors, and models of ischemic brain damage). We hypothesize the beneficial effects of EGb in the neurotherapeutic management of long-term COVID-19 symptoms, evaluated using either in vitro cellular or in vivo animal models of oxidative stress.

The Use of Ginkgo Biloba L. as a Neuroprotective Agent in the Alzheimer's Disease

Alzheimer's disease, a neurodegenerative disease, is one of the most common causes of dementia if elderly people worldwide. Alzheimer's disease leads to the alienation of individuals and their exclusion from social and professional life. It is characterized mainly by the degradation of memory and disorientation, which occurs as a result of the loss of neuronal structure and function in different brain areas. In recent years, more and more attention has been paid to use in the treatment of natural bioactive compounds that will be effective in neurodegenerative diseases, including Alzheimer's disease. G. biloba L. and its most frequently used standardized extract (EGb 761), have been used for many years in supportive therapy and in the prevention of cognitive disorders. The paper presents an overview of reports on the pathogenesis of Alzheimer's disease, as well as a summary of the properties of G. biloba extract and its effects on the possible pathogenesis of the disease. By exploring more about the pathogenesis of the disease and the benefits of G. biloba extract for patients with Alzheimer's disease, it will be possible to create an individualized therapeutic protocol to optimize the treatment.

A biocompatible and injectable hydrogel to boost the efficacy of stem cells in neurodegenerative diseases treatment

AIMS

Stem cell therapies emerged as treatment modalities with potential to cure neurodegenerative diseases (NDs). However, despite high expectations, their clinical use is still limited. Critical issues in treatment outcomes may be related to stem cells formulation and administration route. We develop a hydrogel as a cell carrier, consisting of compounds (phospholipids and hyaluronic acid-HA) naturally present in the central nervous system (CNS). The HA-based hydrogel physically crosslinked with liposomes is designed for direct injection into the CNS to significantly increase the bone marrow mesenchymal stem cells (BMSCs) bioavailability.

MATERIALS AND METHODS

Hydrogel compatibility is confirmed in vitro with BMSCs and in vivo through its intracerebroventricular injection in rats. To assess its efficacy, the main cause of chronic neurologic disability in young adults is selected, namely multiple sclerosis (MS). The efficacy of the developed formulation containing a lower number of cells than previously reported is demonstrated using an experimental autoimmune encephalomyelitis (EAE) rat model.

KEY FINDINGS

The distribution of the engineered hydrogel into corpus callosum can be ideal for NDs treatment, since damage of this white matter structure is responsible for important neuronal deficits. Moreover, the BMSCs-laden hydrogel significantly decreases disease severity and maximum clinical score and eliminated the relapse.

SIGNIFICANCE

The engineering of advanced therapies using this natural carrier can result in efficacious treatments for MS and related debilitating conditions.

Effects of Ginkgo biloba on Early Decompression after Spinal Cord Injury

Spinal cord injury (SCI) is a severe trauma of the central nervous system characterized by high disability and high mortality. Clinical progress has been achieved in understanding the pathological mechanism of SCI and its early treatment, but the results are unsatisfactory. In China, increasing attention has been paid to the role of traditional Chinese medicine in the treatment of SCI. In particular, extracts from the leaves of Ginkgo biloba (maidenhair tree), which have been reported to exert anti-inflammatory and antioxidant properties and repair a variety of active cellular damage, have been applied therapeutically for centuries. In this study, we established a rat SCI model to investigate the effects of Ginkgo biloba leaves on decompression at different stages of SCI. The application of Ginkgo biloba leaves during the decompression of SCI at different time points, the neurological recovery of SCI, and the underlying molecular mechanism were explored. The findings provide reliable experimental data that reveal the mechanism of GBI (Ginkgo biloba injection) in the clinical treatment of SCI.

Effects of Ginkgo biloba extract EGb761 on neural differentiation of stem cells offer new hope for neurological disease treatment

Stem cell transplantation has brought new hope for the treatment of neurological diseases. The key to stem cell therapy lies in inducing the specific differentiation of stem cells into nerve cells. Because the differentiation of stem cells in vitro and in vivo is affected by multiple factors, the final differentiation outcome is strongly associated with the microenvironment in which the stem cells are located. Accordingly, the optimal microenvironment for inducing stem cell differentiation is a hot topic. EGb761 is extracted from the leaves of the Ginkgo biloba tree. It is used worldwide and is becoming one of the focuses of stem cell research. Studies have shown that EGb761 can antagonize oxygen free radicals, stabilize cell membranes, promote neurogenesis and synaptogenesis, increase the level of brain-derived neurotrophic factors, and replicate the environment required during the differentiation of stem cells into nerve cells. This offers the possibility of using EGb761 to induce the differentiation of stem cells, facilitating stem cell transplantation. To provide a comprehensive reference for the future application of EGb761 in stem cell therapy, we reviewed studies investigating the influence of EGb761 on stem cells. These started with the composition and neuropharmacology of EGb761, and eventually led to the finding that EGb761 and some of its important components play important roles in the differentiation of stem cells and the protection of a beneficial microenvironment for stem cell transplantation.