Intracerebral hirudin injection alleviates cognitive impairment and oxidative stress and promotes hippocampal neurogenesis in rats subjected to cerebral ischemia

Aerobic exercise, an effective intervention for cognitive impairment after ischemic stroke

Cognitive dysfunction is a common and debilitating complication following ischemic stroke, significantly impairing the quality of life of patients. In recent years, aerobic exercise has emerged as a promising non-pharmacological intervention to mitigate post-stroke cognitive impairment (PSCI). This review synthesizes current evidence on the efficacy and mechanisms of aerobic exercise in enhancing cognitive recovery after ischemic stroke. Key mechanisms include improved cerebral hemodynamics through enhanced cerebral blood flow (CBF), promotion of neuroplasticity via brain-derived neurotrophic factor (BDNF)-mediated pathways, suppression of neuroinflammation (e.g., NLRP3 inflammasome inhibition), and attenuation of oxidative stress. Preclinical and clinical studies demonstrate that aerobic exercise modalities such as gait training, cycling, and aquatic therapy enhance cognitive domains including memory, executive function, and attention, with optimal benefits observed at moderate-to-high intensity and a frequency of ≥3 sessions per week. Despite robust evidence, challenges remain in standardizing exercise protocols and addressing individual variability in treatment response. Future research should prioritize large-scale randomized controlled trials to validate long-term cognitive benefits and identify biomarkers for personalized rehabilitation strategies. This review underscores the imperative to integrate aerobic exercise into post-stroke rehabilitation paradigms, offering a dual therapeutic approach to improve both physical and cognitive outcomes.

Engineering hirudin encapsulation in pH-responsive antioxidant nanoparticles for therapeutic efficacy in ischemic stroke model mice

This study introduces a novel pH-sensitive, hirudin-loaded antioxidant nanoparticle (HD@iNanoAOX) aimed at addressing the challenges of hirudin's short half-life and hemorrhagic transformation. HD@iNanoAOX was engineered to safeguard and prolong hirudin's bioactivity by encapsulating it within antioxidative nanoparticles, facilitating its gradual release in acidic environments. The efficacy of this approach was validated through both ex vivo and in vivo experiments. Ex vivo thrombolytic assays demonstrated that HD@iNanoAOX maintained effective clot lysis activity under acidic conditions. In vivo assessments revealed that HD@iNanoAOX significantly prolonged hirudin's half-life and reduced cerebral infarct volume in a mouse model of middle cerebral artery occlusion (MCAO). Furthermore, HD@iNanoAOX treatment mitigated cerebral oxidative stress, suppressed hemorrhagic transformation, and prevented blood-brain barrier (BBB) disruption. These findings suggest that the combined thrombolytic and antioxidative properties of HD@iNanoAOX offer a promising therapeutic approach for ischemic stroke. Nonetheless, further research is warranted to optimize the formulation and assess its safety and efficacy in clinical settings.

Hirudin promotes cerebral angiogenesis and exerts neuroprotective effects in MCAO/R rats by activating the Wnt/β-catenin pathway

OBJECTIVE

Hirudin has shown potential in promoting angiogenesis and providing neuroprotection in ischemic stroke; however, its therapeutic role in promoting cerebrovascular angiogenesis remains unclear. In this study, we aimed to investigate whether hirudin exerts neuroprotective effects by promoting angiogenesis through the regulation of the Wnt/β-catenin signaling pathway.

METHODS

An in vitro model of glucose and oxygen deprivation/reperfusion (OGD/R) was established using rat brain microvascular endothelial cells (BMECs). The effects of hirudin on OGD/R cell viability were assessed using the cell counting kit-8 (CCK-8) assay. The angiogenic potential of hirudin was evaluated using Transwell and tube formation assays. In vivo, a middle cerebral artery occlusion/reperfusion (MCAO/R) model was created in rats. The neuroprotective effects of hirudin were assessed using the modified neurological severity score (mNSS), Hematoxylin and eosin (H&E) staining, 2,3,5-Triphenyltetrazolium chloride (TTC) staining, and immunofluorescence staining. Dickkopf-1 (DKK1), a specific inhibitor of this pathway, was introduced in order to investigate the role of the Wnt/β-catenin pathway. The effects of hirudin on the Wnt/β-catenin pathway were examined through immunohistochemistry, western blotting, and reverse transcription quantitative polymerase chain reaction (RT-qPCR).

RESULTS

Hirudin significantly improved BMEC survival and enhanced both cell migration and tube formation in the OGD/R model. In the MCAO/R model, hirudin reduced the mNSS score, alleviated pathological damage, decreased infarction volume, and increased the expression of key angiogenic factors, including CD34, vascular endothelial growth factor (VEGF), and angiopoietin-2 (Ang-2). In addition, hirudin activated the Wnt/β-catenin pathway, leading to elevated levels of Wnt3a and β-catenin.

CONCLUSION

Hirudin has substantial neuroprotective effects associated with the promotion of angiogenesis in the ischemic penumbra. This mechanism is mediated by the regulation of the Wnt/β-catenin pathway.

Novel drug delivery systems for hirudin-based product development and clinical applications

Hirudin, a natural biological polypeptide macromolecule secreted by the salivary glands of medicinal leech, is a specific thrombin inhibitor with multiple favourable bioactivities, including anti-coagulation, anti-fibrotic, and anti-tumour. Despite several anticoagulants have been widely applied in clinic, hirudin shows advantages in reducing the incidence of bleeding side effects by virtue of its high specificity in binding to thrombin. As a result, hirudin has been tested in clinical practice to prevent and treat several complex diseases. However, the application of this polypeptide macromolecule is compromised by its low bioavailability and bioactivity due to poor serum stability and susceptibility to protease degradation in vivo. To overcome these drawbacks, several studies have proposed novel drug delivery systems (NDDSs) to prevent the degradation and increase the targeting efficiency of hirudin. This systematic review summarises the clinical research on hirudin, including its classification and bioactivities, and highlights the opportunities and challenges in the clinical use of hirudin. The NDDSs designed to enhance the bioavailability and bioactivity of hirudin are discussed to explore its application in the treatment of related diseases. This review may considerably contribute to the advancement of delivery science and technology, particularly in the context of polypeptide-based therapeutics.

Chuanzhitongluo capsule improves cognitive impairment in mice with chronic cerebral hypoperfusion via the cholinergic anti-inflammatory pathway

Vascular cognitive impairment (VCI) has become a common disease-causing cognitive deficit in humans, second only to Alzheimer's Disease (AD). Chuanzhitongluo capsule (CZTL) is a Traditional Chinese Medicine (TCM) preparation known for its effective protection against cerebral ischemia. However, its potential to ameliorate VCI remains unclear. This study aimed to investigate the cognitive improvement effects of CZTL in a mouse model of VCI. Chronic cerebral hypoperfusion (CCH) was induced in mice by bilateral common carotid artery stenosis (BCAS) to simulate the pathological changes associated with VCI. Spatial learning and memory abilities were assessed using the Morris Water Maze (MWM). RNA sequencing (RNA-Seq) was employed to identify differentially expressed genes (DEGs) in the hippocampus. Levels of inflammatory factors were measured through enzyme-linked immunosorbent assay (ELISA), while immunofluorescence (IF) determined the expression intensity of target proteins. Western Blot (WB) confirmed the final action pathway. Results indicated that CZTL significantly improved the spatial learning and memory abilities of CCH mice, along with alterations in gene expression profiles in the hippocampus. It also reduced neuroinflammation in the hippocampus and upregulated the choline acetyltransferase (ChAT) and α7 subunit-containing nicotinic acetylcholine receptor (α7nAChR), which are in synaptic plasticity and neuronal development. Moreover, CZTL inhibited the NF-κB signaling pathway. In conclusion, CZTL may alleviate neuroinflammation induced by CCH and improve cognitive impairment in CCH mice by regulating the cholinergic anti-inflammatory pathway (CAIP) involving ChAT/α7nAChR/NF-κB.