Neuroprotective mechanisms of 3-n-butylphthalide in neurodegenerative diseases

Microglial crosstalk with astrocytes and immune cells in amyotrophic lateral sclerosis

In recent years, biomedical research efforts aimed to unravel the mechanisms involved in motor neuron death that occurs in amyotrophic lateral sclerosis (ALS). While the main causes of disease progression were first sought in the motor neurons, more recent studies highlight the gliocentric theory demonstrating the pivotal role of microglia and astrocyte, but also of infiltrating immune cells, in the pathological processes that take place in the central nervous system microenvironment. From this point of view, microglia-astrocytes-lymphocytes crosstalk is fundamental to shape the microenvironment toward a pro-inflammatory one, enhancing neuronal damage. In this review, we dissect the current state-of-the-art knowledge of the microglial dialogue with other cell populations as one of the principal hallmarks of ALS progression. Particularly, we deeply investigate the microglia crosstalk with astrocytes and immune cells reporting in vitro and in vivo studies related to ALS mouse models and human patients. At last, we highlight the current experimental therapeutic approaches that aim to modulate microglial phenotype to revert the microenvironment, thus counteracting ALS progression.

Co-administration of Nanowired DL-3-n-Butylphthalide (DL-NBP) Together with Mesenchymal Stem Cells, Monoclonal Antibodies to Alpha Synuclein and TDP-43 (TAR DNA-Binding Protein 43) Enhance Superior Neuroprotection in Parkinson's Disease Following Concussive Head Injury

dl-3-n-butylphthalide (dl-NBP) is one of the potent antioxidant compounds that induces profound neuroprotection in stroke and traumatic brain injury. Our previous studies show that dl-NBP reduces brain pathology in Parkinson's disease (PD) following its nanowired delivery together with mesenchymal stem cells (MSCs) exacerbated by concussive head injury (CHI). CHI alone elevates alpha synuclein (ASNC) in brain or cerebrospinal fluid (CSF) associated with elevated TAR DNA-binding protein 43 (TDP-43). TDP-43 protein is also responsible for the pathologies of PD. Thus, it is likely that exacerbation of brain pathology in PD following brain injury may be thwarted using nanowired delivery of monoclonal antibodies (mAb) to ASNC and/or TDP-43. In this review, the co-administration of dl-NBP with MSCs and mAb to ASNC and/or TDP-43 using nanowired delivery in PD and CHI-induced brain pathology is discussed based on our own investigations. Our observations show that co-administration of TiO2 nanowired dl-NBP with MSCs and mAb to ASNC with TDP-43 induced superior neuroprotection in CHI induced exacerbation of brain pathology in PD, not reported earlier.

Dl-3-n-Butylphthalide Reduced Neuroinflammation by Inhibiting Inflammasome in Microglia in Mice after Middle Cerebral Artery Occlusion

The inflammatory response is one of the key events in cerebral ischemia, causing secondary brain injury and neuronal death. Studies have shown that the NLRP3 inflammasome is a key factor in initiating the inflammatory response and that Dl-3-n-butylphthalide (NBP) can attenuate the inflammatory response and improve neuronal repair during ischemic stroke. However, whether NBP attenuates the inflammatory response via inhibition of NLRP3 remains unclear. A 90 min middle cerebral artery occlusion was induced in 62 2-month-old adult male ICR mice, and NBP was administered by gavage zero, one, or two days after ischemia. Brain infarct volume, neurological deficits, NLRP3, microglia, and neuronal death were examined in sacrificed mice to explore the correction between NBP effects and NLRP3 expression. NBP significantly reduced infarct volume and attenuated neurological deficits after ischemic stroke compared to controls (p < 0.05). Moreover, it inhibited ASC+ microglia activation and NLRP3 and CASP1 expression in ischemic mice. In addition, neuronal apoptosis was reduced in NBP-treated microglia cultures (p < 0.05). Our results indicate that NBP attenuates the inflammatory response in ischemic mouse brains, suggesting that NBP protects against microglia activation via the NLRP3 inflammasome.

Effects of Butylphthalide Sodium Chloride Injection Combined with Edaravone Dexborneol on Neurological Function and Serum Inflammatory Factor Levels in Sufferers Having Acute Ischemic Stroke

For investigating an influence on butylphthalide sodium chloride injection combined with edaravone dexborneol on neurological function and serum inflammatory factor levels in sufferers having acute ischemic stroke, 120 sufferers having acute ischemic stroke from September 2020 to September 2021 are chosen for the study subjects. In line with the diverse therapies, they took part in a control group and the study group, with 60 examples in each group. The control group is treated with edaravone dexborneol, and the study group is treated with butylphthalide sodium chloride injection, based on the control group. The posttreatment curative efficacy on the two groups is recorded, and treatment of both the two groups is compared. Before and after neurological function indexes (NIHSS and mRS), inflammatory factor indexes (IL-6, CRP, and TNF-α), life quality index (Barthel index), hemorheological indexes (plasma-specific viscosity), and neurological levels of NSE are logged and contrasted between the two groups of adverse reactions during therapy. Postcure, the overall response rate and Barthel index of the study group obviously overtop those of the control group (p < 0.05). IL-6, CRP, TNF-α, NSE, plasma specific viscosity, and NIHSS and mRS scores obviously hypodown those of the control group (p < 0.05), and untoward effects on the two groups during curing are lower, and the discrepancy is not obvious(p > 0.05). Butylphthalide sodium chloride injection combined with edaravone dexborneol can enhance curative efficacy on sufferers having acute ischemic stroke, improve neurological function, blood rheology, and quality of life, and decrease the secretion of cytokine, having a better effect and high medication safety.

DL-3-n-butylphthalide Increases Collateriogenesis and Functional Recovery after Focal Ischemic Stroke in Mice

Recent evidence indicates that collateral circulation is critical for the outcome of ischemic stroke. DL-3-n-butylphthalide (NBP), a synthesized compound based on an extract from seeds of celery Apium graveolens Linn, has been used as a therapeutic drug, showing multiple neuroprotective and regenerative activities. A potential effect of NBP on collateral arterial regulation is unknown. We examined the effects of NBP on arteriogenesis of collateral arteries in vitro and a mouse ischemic stroke model. In cultures of mouse iPS cell-derived vascular progenitors, NBP (10 μM) significantly increased α-smooth muscle actin (αSMA)/CD-31 co-labeled cells and the expression of newly formed vasculature marker PDGFRα. A sensorimotor cortex ischemia was induced in transgenic mice expressing αSMA-GFP that allowed direct observation of arterial vasculatures in brain regions. NBP (80 mg/kg) was intranasally delivered 1 hr after stroke and once daily for 14 days. To label proliferating cells, 5-Bromo-2’-deoxyuridine (BrdU, 50 mg/kg, i.p.) was administrated every day from 3 days after stroke. Western blotting of peri-infarct tissue detected increased expressions of VEGF, Ang-1 and reduced nNOS level in NBP-treated mice. The NBP treatment significantly increased αSMA/BrdU co-labeled cells, the diameter of ipsilateral collaterals, and arterial area in ischemic and peri-infarct regions examined 14 days after stroke. Examined 3 days after stroke, NBP prevented functional deficits in the cylinder test and corner test. The NBP treatment of 14 days improved the local cerebral blood flow (LCBF) and functional performance in multiple tests. Thus, NBP promotes collateriogenesis, short and long-term structural and functional improvements after ischemic stroke.

Dl-3-n-Butylphthalide Ameliorates Diabetic Nephropathy by Ameliorating Excessive Fibrosis and Podocyte Apoptosis

Diabetic nephropathy (DN) is a common diabetes associated complication. Thus, it is important to understand the pathological mechanism of DN and find the appropriate therapeutic strategy for it. Dl-3-n-Butylphthalide (DL-NBP) has anti-inflammatory and antioxidant effects, and been widely used for the treatment of stroke and cardiovascular diseases. In this study, we selected three different doses (20, 60, and 120 mg⋅kg^-1 d^-1) of DL-NBP and attempted to elucidate its role and molecular mechanism underlying DN. We found that DL-NBP, especially at the dose of 60 or 120 mg⋅kg^-1 d^-1, could significantly ameliorate diabetes-induced elevated blood urea nitrogen (BUN) and creatinine level, and alleviate renal fibrosis. Additionally, the elevated expressions of collagen and α-smooth muscle actin (α-SMA) in the kidney from db/db mice were found to be significantly suppressed after DL-NBP treatment. Furthermore, mechanistic studies revealed that DL-NBP inhibits pro-inflammatory cytokine levels, thereby ameliorating the development of renal fibrosis. Moreover, we found that DL-NBP could not only reduce the endoplasmic reticulum stress (ERS), but also suppress activation of the renin-angiotensin system to inhibit vascular endothelial growth factor (VEGF) level, which subsequently reduces the podocyte apoptosis in kidney of db/db mice. In a word, our findings suggest that DL-NBP may be a potential therapeutic drug in the treatment of DN.

Dl-3-n-Butylphthalide Alleviates Behavioral and Cognitive Symptoms Via Modulating Mitochondrial Dynamics in the A53T-α-Synuclein Mouse Model of Parkinson's Disease

Background

Aggregation and neurotoxicity of the presynaptic protein α-synuclein and the progressive loss of nigral dopaminergic neurons are believed to be the key hallmarks of Parkinson’s disease (PD). A53T mutant α-synuclein causes early onset PD and more severe manifestations. A growing body of evidence shows that misfolding or deposition of α-synuclein is linked to the maintenance of mitochondrial dynamics, which has been proven to play an important role in the pathogenesis of PD. It has been observed that Dl-3-n-butylphthalide (NBP) may be safe and effective in improving the non-tremor-dominant PD. However, the potential mechanism remains unclear. This study aimed to investigate whether NBP could decrease the loss of dopaminergic neurons and α-synuclein deposition and explore its possible neuroprotective mechanisms.

Methods

A total of 20 twelve-month-old human A53T α-synuclein transgenic mice and 10 matched adult C57BL/6 mice were included in the study; 10 adult C57BL/6 mice were selected as the control group and administered with saline (0.2 ml daily for 14 days); 20 human A53T α-synuclein transgenic mice were randomly divided into A53T group (treated in the same manner as in the control group) and A53T + NBP group (treated with NBP 0.2 ml daily for 14 days). Several markers of mitochondrial fission and fusion and mitophagy were determined, and the behavioral, olfactory, and cognitive symptoms were assessed as well.

Results

In the present study, it was observed that the A53T-α-synuclein PD mice exhibited anxiety-like behavioral disturbance, impairment of coordination ability, memory deficits, and olfactory dysfunction, loss of dopaminergic neurons, and α-synuclein accumulation. Meanwhile, the mitofusin 1 expression was significantly decreased, and the mitochondrial number and dynamin-related protein 1, Parkin, and LC3 levels were increased. The detected levels of all markers were reversed by NBP treatment, and the mitochondrial morphology was partially recovered.

Conclusion

In the present study, a valuable neuropharmacological role of NBP has been established in the A53T-α-synuclein PD mouse model. Possible neuroprotective mechanisms might be that NBP is involved in the maintenance of mitochondrial dynamics including mitochondrial fission and fusion and clearance of damaged mitochondria. It is essential to perform further experiments to shed light on the precise mechanisms of NBP on mitochondrial homeostasis.

Dl-butylphthalide inhibits rotenone-induced oxidative stress in microglia via regulation of the Keap1/Nrf2/HO-1 signaling pathway

Activated microglia are a source of superoxide which often increases oxidative stress in the brain microenvironment, increase production of reactive oxygen species (ROS) and directly or indirectly lead to dopaminergic neuronal death in the substantia nigra. Thus superoxide contributes to the pathogenesis of Parkinson's disease (PD). Evidence suggests that mitochondria are the main source of ROS, which cause oxidative stress in cells. Levels of ROS are thus associated with the function of the mitochondrial complex. Therefore, protecting the mitochondrial function of microglia is important for the treatment of PD. Dl-butylphthalide (NBP), a compound isolated from Chinese celery seeds, has been approved by the China Food and Drug Administration for the treatment of acute ischemic stroke. Recently, NBP demonstrated therapeutic potential for PD. However, the mechanism underlying its neuroprotective effect remains unclear. The present study aimed to investigate the effect of NBP on rotenone-induced oxidative stress in microglia and its underlying mechanisms. The results demonstrated that NBP treatment significantly increased mitochondrial membrane potential and decreased ROS level in rotenone-induced microglia. Western blot analysis showed that NBP treatment promoted entry of nuclear respiratory factor-2 (Nrf2) into the nucleus, increased heme oxygenase-1 (HO-1) expression and decreased the level of the Nrf2 inhibitory protein, Kelch-like ECH-associated protein 1. Overall, the findings indicated that NBP inhibited rotenone-induced microglial oxidative stress via the Keap1/Nrf2/HO-1 pathway, suggesting that NBP may serve as a novel agent for the treatment of PD.

Improvement of cerebral ischemia-reperfusion injury by L-3-n-butylphthalide through promoting angiogenesis

Cerebral ischemia/reperfusion (I/R) injury may lead to a poor prognosis for ischemic stroke patients after reperfusion therapy, and currently, lacks effective therapeutic intervention. This study aimed to investigate the effects of L-3-n-butylphthalide (L-NBP) on cerebral I/R injury in rats. Rat models of cerebral I/R injury were established using the middle cerebral artery occlusion/refusion (MACO/R) surgery and were administrated intragastrically with L-NBP or vehicle. We found that L-NBP attenuated the histological damages and reduced the brain hematoma in MACO/R rats. L-NBP also significantly improved the neurological function, alleviated the brain edema, and reduced the permeability of blood-brain barrier of MACO/R rats. Moreover, we detected that L-NBP considerably facilitated microvessel formation in the lesion area of brain in MACO/R rats. Finally, we found that L-NBP significantly increased the protein and mRNA expression levels of Nrf2, HIF-1α, and VEGF in the brain of MACO/R rats. In conclusion, our results demonstrated that L-NBP exerted significant beneficial effects on cerebral I/R injury in rats through promoting angiogenesis, which may be associated with the activation of Nrf2/HIF-1α/VEGF signaling pathway. Our results suggested that L-NBP could be a potential therapeutic drug for cerebral I/R injury.

From Seeds of Apium graveolens Linn. to a Cerebral Ischemia Medicine: The Long Journey of 3-n-Butylphthalide

3-n-Butylphthalide (NBP) as well as its derivatives and analogues (NBPs), in racemic or enantiomerically pure forms, possess potent and diverse pharmacological properties and have shown a great potential therapeutic interest for many human conditions, especially for cerebral ischemia. This Perspective outlines the synthesis and therapeutic applications of NBPs.