DL-3-n-butylphthalide-induced neuroprotection in rat models of asphyxia-induced cardiac arrest followed by cardiopulmonary resuscitation

DL-3-N-BUTYLPHTHALIDE ALLEVIATES CARDIAC DYSFUNCTION AND INJURY POSSIBLY BY INHIBITING CELL PYROPTOSIS AND INFLAMMATION VIA THE CGAS-STING-TBK1 PATHWAY IN A PORCINE MODEL OF HEMORRHAGE-INDUCED CARDIAC ARREST

ABSTRACT

Introduction: Dl-3-n-butylphthalide (NBP), a small molecular compound extracted from celery seeds, has been shown to exhibit diverse pharmacological activities, including anti-inflammatory, antioxidative, and anti-apoptotic effects. Recent studies have highlighted its efficacy in treating various cardiovascular conditions, such as myocardial infarction, hypertrophy, heart failure, and cardiotoxicity. This study aimed to investigate whether NBP could alleviate cardiac dysfunction and injury following hemorrhage-induced cardiac arrest (HCA) in a porcine model and elucidate its potential mechanisms. Methods: Seventeen pigs were randomized into three groups: sham (n = 5), HCA + vehicle (n = 5), and HCA + NBP (n = 7). In the HCA + vehicle and HCA + NBP groups, the HCA model was established by continuous bleeding at a rate of 2 mL/kg/min to induce cardiac arrest. Cardiac arrest was maintained for 7 min, followed by the reinfusion of 50% of the shed blood at a rate of 5 mL/kg/min. After successful resuscitation, the HCA + NBP group received an intravenous dose of 2.5 mg/kg of NBP within 120 min. Post-resuscitation cardiac function (stroke volume, global ejection fraction) and injury biomarkers (cardiac troponin I, creatine kinase-MB) were assessed at regular intervals. At the end of the post-resuscitation observation, cardiac tissue samples were collected to assess: histopathological injury; cellular apoptosis; levels of pro-inflammatory cytokines, including tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), interleukin-6 (IL-6), and interleukin-18 (IL-18); the expression levels of NOD-like receptor pyrin domain 3 (NLRP3), caspase 1, gasdermin D (GSDMD), cyclic-GMP-AMP synthase (cGAS), stimulator of interferon genes (STING), and tank-binding kinase 1 (TBK1); and the integrated optical density (IOD) of GSDMD N-terminal (GSDMD-N), phosphorylated STING (p-STING), and phosphorylated TBK1 (p-TBK1). Results: Following resuscitation, both stroke volume and global ejection fraction were significantly reduced, while serum levels of cardiac troponin I and creatine kinase-MB were markedly elevated in the HCA + vehicle and HCA + NBP groups compared with the sham group. However, the extent of cardiac dysfunction and injury was significantly attenuated in the HCA + NBP group relative to the HCA + vehicle group. At 24 h post-resuscitation, substantial cardiac pathological injury and apoptosis were observed. Additionally, pyroptosis-related proteins (NLRP3, caspase-1, GSDMD, GSDMD-N) were upregulated, inflammatory markers (TNF-α, IL-1β, IL-6, IL-18) were elevated, and the activation of the cGAS-STING-TBK1 pathway (cGAS, STING, TBK1, p-STING, p-TBK1) were noted in both the HCA + vehicle and HCA + NBP groups compared with the sham group. Notably, these pathological changes were significantly attenuated in the HCA + NBP group compared with the HCA + vehicle group. Conclusions: NBP provided substantial cardiac protection following HCA and resuscitation in pigs. This protective effect was likely mediated through the inhibition of cell pyroptosis and inflammation by suppressing the cGAS-STING-TBK1 signaling pathway.

Neuroprotective Approaches for Brain Injury After Cardiac Arrest: Current Trends and Prospective Avenues

With the implementation of improved bystander cardiopulmonary resuscitation techniques and public-access defibrillation, survival after out-of-hospital cardiac arrest (OHCA) has increased significantly over the years. Nevertheless, OHCA survivors have residual anoxia/reperfusion brain damage and associated neurological impairment resulting in poor quality of life. Extracorporeal membrane oxygenation or targeted temperature management has proven effective in improving post-cardiac arrest (CA) neurological outcomes, yet considering the substantial healthcare costs and resources involved, there is an urgent need for alternative treatment strategies that are crucial to alleviate brain injury and promote recovery of neurological function after CA. In this review, we searched PubMed for the latest preclinical or clinical studies (2016-2023) utilizing gas-mediated, pharmacological, or stem cell-based neuroprotective approaches after CA. Preclinical studies utilizing various gases (nitric oxide, hydrogen, hydrogen sulfide, carbon monoxide, argon, and xenon), pharmacological agents targeting specific CA-related pathophysiology, and stem cells have shown promising results in rodent and porcine models of CA. Although inhaled gases and several pharmacological agents have entered clinical trials, most have failed to demonstrate therapeutic effects in CA patients. To date, stem cell therapies have not been reported in clinical trials for CA. A relatively small number of preclinical stem-cell studies with subtle therapeutic benefits and unelucidated mechanistic explanations warrant the need for further preclinical studies including the improvement of their therapeutic potential. The current state of the field is discussed and the exciting potential of stem-cell therapy to abate neurological dysfunction following CA is highlighted.

Rat model of asphyxia-induced cardiac arrest and resuscitation

Neurologic injury after cardiopulmonary resuscitation is the main cause of the low survival rate and poor quality of life among patients who have experienced cardiac arrest. In the United States, as the American Heart Association reported, emergency medical services respond to more than 347,000 adults and more than 7,000 children with out-of-hospital cardiac arrest each year. In-hospital cardiac arrest is estimated to occur in 9.7 per 1,000 adult cardiac arrests and 2.7 pediatric events per 1,000 hospitalizations. Yet the pathophysiological mechanisms of this injury remain unclear. Experimental animal models are valuable for exploring the etiologies and mechanisms of diseases and their interventions. In this review, we summarize how to establish a standardized rat model of asphyxia-induced cardiac arrest. There are four key focal areas: (1) selection of animal species; (2) factors to consider during modeling; (3) intervention management after return of spontaneous circulation; and (4) evaluation of neurologic function. The aim was to simplify a complex animal model, toward clarifying cardiac arrest pathophysiological processes. It also aimed to help standardize model establishment, toward facilitating experiment homogenization, convenient interexperimental comparisons, and translation of experimental results to clinical application.

NBP Cytoprotective Effects Promoting Neuronal Differentiation in BMSCs by Inhibiting the p65/Hes1 Pathway

Background

Bone marrow-derived mesenchymal stem cell (BMSC) transplantation has become an effective method for treating neurodegenerative diseases.

Objectives

This study investigated the effect of 3-N-butylphthalide (NBP) on the neuronal differentiation of BMSCs and its potential mechanism.

Methods

In this study, a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay was performed to detect cell proliferation and terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) staining was conducted to detect the apoptosis of BMSCs. Quantitative real-time polymerase chain reaction (RT-qPCR) and Western blot analysis were performed to detect the messenger RNA (mRNA) and protein expression levels, respectively. An enzyme-linked immunosorbent serologic assay assessed the levels of interleukin-1β, tumor necrosis factor-α, and cyclic adenosine monophosphate (cAMP). Moreover, a flow cytometry assay was used to detect the proportion of active β-tubulin III (TUJ-1) cells, and TUJ-1 expression was observed by immunofluorescence assay.

Results

The results showed that a low concentration of NBP promoted the proliferation and induction of BMSC neuronal differentiation while inhibiting apoptosis, the production of inflammatory factors, and p65 expression. Compared with differentiation induction alone, combined NBP treatment increased the levels of nestin, neuron-specific enolase (NSE), TUJ-1, and microtubule-associated protein 2 (MAP2) protein, as well as the ratio of TUJ-1-positive cells and cAMP expression. Furthermore, p65 overexpression weakened the effect of NBP, and the overexpression of hairy and enhancer of split homolog-1 (HES1) reversed the effect of NBP in the induction of BMSC neuronal differentiation in vitro.

Conclusions

We confirmed that NBP exhibited potential therapeutic properties in the stem cell transplantation treatment of neurodegenerative diseases by protecting cells and promoting BMSC neuronal differentiation by inhibiting the p65/HES 1 pathway.