Cerebral hypoperfusion is a pivotal risk factor for vascular dementia (VD), for which effective therapy remains inadequate. Persistent inflammatory responses and excessive chemotaxis of microglia/macrophages in the brain may accelerate the progression of VD. Endocannabinoids are involved in neuronal protection against inflammation-induced neuronal injury. Cannabinoids acting at cannabinoid receptor 2 (CB2R) can decrease inflammation. Based on the identification of paeoniflorin (PF) as a CB2R agonist, we investigated the neuroprotective and microglia/macrophages M1 to M2 polarization promoting effects of PF in a permanent four-vessel occlusion rat model. One week after surgery, PF was intraperitoneally administered at a dose of 40 mg/kg once a day for 28 successive days. The effects of PF on memory deficit were investigated by a Morris water maze test, and the effects of PF on hippocampal neuronal damage were evaluated by light microscope and electron microscope. The mRNA and protein expression levels of key molecules related to the M1/M2 polarization of microglia/macrophages were assessed by RT-qPCR and Western blotting, respectively. Administration of PF could significantly attenuate cerebral hypoperfusion-induced impairment of learning and memory and reduce the morphological and ultrastructural changes in the hippocampal CA1 region of rats. Moreover, PF promoted an M1 to M2 phenotype transition in microglia/macrophages in the hippocampus of rats. In addition to its inhibitory property against proinflammatory M1 mediator expression, such as IL-1β, IL-6, TNF-α and NO, PF dramatically up-regulated expression of anti-inflammatory cytokines IL-10 and TGF-β1. Importantly, CB2R antagonist AM630 abolished these beneficial effects produced by PF on learning, memory and hippocampus structure in rats, as well as the polarization of microglia/macrophages to the M2 phenotype. Additionally, PF treatment significantly inhibited cerebral hypoperfusion-induced mTOR/NF-κB proinflammatory pathway and enhanced PI3K/Akt anti-inflammatory pathway. Effects of PF on these signaling pathways were effectively attenuated when rats were co-treated with PF and AM630, indicating that the mTOR/NF-κB and PI3K/Akt signaling pathways were involved in the PF effects through CB2R activation. These findings demonstrated PF exerts its neuroprotective effect and shifts the inflammatory milieu toward resolution by modulation of microglia/macrophage polarization via CB2R activation.

Background: Acute lung injury (ALI) is a life-threatening respiratory condition and one of the leading causes of mortality worldwide, accounting for approximately 20% of global annual deaths. Despite its high prevalence and severity, effective therapeutic options remain limited. Eupatorium lindleyanum DC., a traditional medicinal herb, has demonstrated therapeutic potential against pulmonary diseases, particularly ALI, in both clinical and experimental settings. However, the protective effects and underlying mechanisms of its characteristic sesquiterpene lactone components against ALI remain unclear. Objective: This study aimed to evaluate the protective effects of sesquiterpene lactones from Eupatorium lindleyanum DC. (SLEL) against lipopolysaccharide (LPS)-induced ALI both in vivo and in vitro. Furthermore, it sought to elucidate the underlying mechanisms by integrating network pharmacology, multi-omics approaches (transcriptomics, metabolomics, and 16S rRNA sequencing), and various molecular biology techniques. Results: SLEL significantly attenuated inflammatory injury in alveolar epithelial cells and alleviated pulmonary edema, hemorrhage, and inflammatory infiltration in rats, accompanied by reduced TNF-α, IL-6, and IL-1β levels and improved lung injury indices. Mechanistically, SLEL exerted dual suppression of the PI3K-Akt and MAPK-NF-κB pathways. Network pharmacology, molecular docking, and UPLC-MS analyses identified Eupalinolide A and Eupalinolide K as potential bioactive constituents, which were further validated to inhibit phosphorylation of key signaling proteins, thereby partially accounting for SLEL’s pharmacological effects. Multi-omics integration further revealed that SLEL restored bile acid metabolism, reshaped gut microbial diversity, and reconstructed the microbiota–metabolite–inflammatory cytokine network, thereby maintaining gut–lung axis homeostasis and enhancing anti-inflammatory effects. Conclusions: SLEL alleviates ALI through multi-component synergistic actions that suppress pro-inflammatory signaling and modulate the gut–lung axis. These findings highlight the potential of SLEL as a promising therapeutic candidate for the treatment of ALI.

Cytokine storm is a central pathogenic mechanism underlying sepsis-induced acute lung injury (SALI) and severe coronavirus disease 2019 (COVID-19), yet effective therapeutic strategies remain limited. Eupatorium lindleyanum DC. (EL), a traditional Chinese medicinal herb, has been reported to possess anti-inflammatory, antioxidant, and antiviral-related activities; however, its protective mechanisms in SALI and virus-associated inflammatory lung injury remain incompletely understood. In this study, an integrated strategy combining computational prediction and experimental validation was employed to investigate the therapeutic potential and underlying mechanisms of EL. The chemical constituents of EL were characterized by UPLC–Q–TOF/MS, followed by network pharmacology, molecular docking, and molecular dynamics analyses to predict key targets and signaling pathways. A cecal ligation and puncture (CLP)-induced SALI rat model was used to evaluate lung histopathology, pulmonary edema, cytokine production, and inflammatory signaling activation. In parallel, LPS-stimulated RAW264.7 macrophages were used to assess cytokine secretion and pathway regulation in vitro. In addition, a SARS-CoV-2 pseudovirus-induced mouse model was employed to further evaluate the in vivo relevance of the representative bioactive compound hyperoside in pseudovirus-associated lung injury. A total of 32 active compounds and 697 putative targets were identified, among which 116 were associated with sepsis and COVID-19. In vivo, EL markedly alleviated lung injury, reduced the lung coefficient and wet/dry ratio, and suppressed excessive production of proinflammatory cytokines and activation of key signaling proteins. In vitro, EL dose-dependently inhibited TNF-α and IL-6 secretion and regulated the PI3K–Akt and NF-κB signaling pathways. Notably, hyperoside showed favorable predicted interactions with PI3K–Akt pathway-related targets (EGFR, PI3K, and Akt), while molecular dynamics simulations supported stable interactions with several COVID-19-related targets, including ACE2, Mpro, and RdRp. Furthermore, hyperoside significantly alleviated SARS-CoV-2 pseudovirus-associated lung injury, reduced ACE2 protein expression, and downregulated EGFR, PI3K, and Akt mRNA levels in vivo. Collectively, these findings indicate that EL exerts protective effects through multi-component, multi-target, and multi-pathway mechanisms, and support its potential value for further investigation in SALI and virus-associated inflammatory lung injury.

Acute inflammation is a fundamental pathological process involved in many immune-related diseases. Eupatorium lindleyanum DC., a traditional medicinal herb, is rich in sesquiterpene lactones (SLEL), which have been reported to exhibit pharmacological activity; however, their antiinflammatory effects and associated molecular changes remain incompletely characterized. In this study, acute inflammatory responses were induced in a xylene-induced mouse ear edema model and a carrageenan-induced rat paw edema model. Tissue injury and inflammatory infiltration were assessed by hematoxylin and eosin staining. Levels of proinflammatory cytokines (TNF-α, IL-6, and IL-1β) were quantified in serum by ELISA, and their transcriptional expression in inflamed tissues was analyzed by quantitative PCR (qPCR). Changes in NF-κB pathway-associated proteins, including phosphorylated IκBα and p65, were evaluated by western blotting. SLEL treatment reduced ear and paw edema and alleviated histopathological features of acute inflammation, including tissue edema, inflammatory cell infiltration, and vascular congestion. In parallel, SLEL administration was associated with decreased serum levels and tissue mRNA expression of Tnf-α, Il-6, and Il-1β. Western blot analysis demonstrated reduced phosphorylation of IκBα and p65 in inflamed tissues following SLEL treatment, indicating modulation of NF-κB-related signaling events. Together, these findings demonstrate an experimental workflow for evaluating the anti-inflammatory activity of SLEL in acute inflammation models and suggest that its effects are associated with reduced pro-inflammatory cytokine expression and altered NF-κB pathway-related signaling.