Ischemic stroke (IS) is a severe, life-threatening condition, constituting 75–80% of all strokes and ranking as the second leading global cause of death (Cassidy and Cramer, 2017; Benjamin et al., 2018; Collaborators, 2021). Recommended treatments for IS, such as intravenous thrombolysis with tissue plasminogen activator and mechanical thrombectomy, face challenges (Powers et al., 2018). Less than 5% of acute ischemic stroke patients receive intravenous thrombolysis within the eligible window, and mechanical thrombectomy, despite successful recanalization, may lead to complications like cerebral hemorrhage and vessel re-occlusion (Saini et al., 2021). The ongoing neuronal degeneration poses persistent challenges for effective treatment and rehabilitation.

Despite the urgent need for a neuroprotective agent with significant clinical impact and adequate safety in treating IS, the majority of effective rodent neuroprotectants have failed in clinical translation (O'Collins et al., 2006; Cook et al., 2012). Repurposing market-approved drugs for cerebral ischemia offers a promising strategy. Dl-3-n-butylphthalide (NBP), synthesized from Apium graveolens seeds, is approved for acute ischemic stroke treatment by the State Food and Drug Administration of China (Abdoulaye and Guo, 2016). NBP exhibits diverse biological effects and plays a role in various diseases (Cui et al., 2013; Wang et al., 2020, 2021; Wu et al., 2020; He et al., 2023). However, clinical reports indicate varied patient responses, likely due to stroke heterogeneity (Ji et al., 2017; Li et al., 2018). Further exploration is needed to understand the multi-target properties of NBP and its underlying mechanisms in IS treatment.

Pyroptosis, a newly discovered form of programmed cell death, is initiated by inflammasomes and caspase activation, resulting in plasma membrane pore formation, cell swelling, or lysis (Ding et al., 2016; Shi et al., 2017). Specifically, stimuli activate nucleotide-binding oligomerization domain-like receptor pyrin domain-containing 3 (NLRP3), transmitting the signal to the adaptor apoptosis-associated speck-like protein containing a caspase (ASC), facilitating Caspase 1 activation. The active Caspase 1 cleaves interleukin (IL)-1β/18 and gasdermin D (GSDMD), and subsequently induces cell death (Wu et al., 2018). Recent research indicates that pyroptosis occurs in the ischemic border zone, affecting glial cells, neuronal cells, and cerebral microvascular endothelial cells, worsening blood-brain barrier (BBB) disruption and brain damage (Long et al., 2023). Additional study shows NBP's anti-pyroptosis effects in certain diseases (Wang et al., 2019; Han et al., 2021; Que et al., 2021), suggesting its potential to regulate NLRP3 inflammasome activation and microglia accumulation after stroke.

In this study, we focused on the NLRP3 inflammasome/pyroptosis signaling pathway, and utilized the dMCAO mouse model to elucidate the therapeutic effects of NBP in IS across acute to recovery phases, as well as its potential role in neuronal cell pyroptosis and microglial cell inflammatory responses.