Glycosides of Buyang Huanwu decoction inhibits pyroptosis associated with cerebral ischemia-reperfusion through Nrf2-mediated antioxidant signaling pathway both in vivo and in vitro

Adenosine A1 receptor agonist alleviates cerebral ischemia/reperfusion injury by inhibiting Nrf2/NLRP3 signaling‑mediated pyroptosis

The present study aimed to investigate whether adenosine A1 receptor (A1R) agonists can alleviate cerebral ischemia/reperfusion (I/R) injury by inhibiting pyroptosis mediated through the nuclear factor erythroid 2-related factor 2 (Nrf2)/NLR family pyrin domain containing 3 (NLRP3) signaling pathway. A total of 36 Sprague-Dawley rats were randomly assigned to the following four groups: Sham (sham group), I/R (model group), adenosine A1 receptor agonist preconditioning [model + adenosine A1R agonist 2-chloro-N(6)-cyclopentyladenosine] group and ML385 (model + adenosine A1R agonist group + Nrf2 pathway inhibitor group). A middle cerebral artery occlusion model was induced using the thread occlusion method. Neurological function was assessed using the Longa scale, brain infarction volume was determined through 2,3,5-triphenyltetrazolium chloride staining, protein expression of Nrf2, NLRP3, caspase-1, GSDMD and IL-1β was assessed using western blotting, and the expression of Nrf2 and GSDMD was assessed using immunofluorescence. The findings revealed that adenosine A1R agonist improved neurological function and reduced infarct size. Mechanistically, this was found to be associated with the activation of the Nrf2/NLRP3 signaling pathway and the suppression of pyroptosis-associated proteins (gasdermin D, caspase-1 and IL-1β) expression. Notably, the Nrf2 inhibitor ML385 reversed the aforementioned effects induced by the adenosine A1R agonist. These results suggest that adenosine A1R agonist can alleviate cerebral I/R injury in rats, potentially by modulating the Nrf2/NLRP3 signaling pathway to inhibit pyroptosis.

Methyl isoeugenol suppresses NLRP3 inflammasome-mediated pyroptosis via activation of Nrf2/NQO1/HO-1 signaling in cerebral ischemia-reperfusion injury

Microglial neuroinflammation is considered to be a vital injury factor aggravating ischemia-reperfusion (I/R) injury on the progression of cerebral ischemic stroke. Mounting evidences have verified the effect of pyroptosis mediated by NLRP3 inflammasome on modulating microglial phenotype, and maintaining the microglial M1/M2 phenotype balance could be a novel target to ameliorate cerebral I/R injury. Herein, we focused on the anti-neuroinflammatory effect of methyl isoeugenol, a bioactive compound isolated from Acorus tatarinowii Schott, on nuclear factor erythroid 2-related factor 2 (Nrf2)-mediated NLRP3 inflammasome in vivo or in vitro. The results showed that methyl isoeugenol reduced cerebral infarct volume, modulated microglia M1/M2 phenotypes, and protected against NLRP3 inflammasome-primed pyroptosis. Mechanistically, methyl isoeugenol increased the nuclear translocation of Nrf2 and decreased that of NF-κB, and consequently, upregulated cellular antioxidants (HO-1 and NQO1), with the increased expression of antioxidant enzymes SOD and the decreased expression of lipid peroxidation MDA. These findings suggest that Nrf2 may serve as a vital target for the protective effect of methyl isoeugenol, making methyl isoeugenol as a promising anti-neuroinflammatory agent for NLRP3 inflammasome mediated microglial neuroinflammation in I/R injury.

Mogroside V ameliorates astrocyte inflammation induced by cerebral ischemia through suppressing TLR4/TRADD pathway

Inflammation and oxidative stress are pivotal factors in the onset and progression of secondary injury following cerebral ischemia-reperfusion (I/R). Mogroside V (MV), a primary active compound of Siraitia grosvenorii, exhibits significant anti-inflammatory and antioxidant properties. However, its specific effects in cerebral ischemia remain unclear. In this study, we evaluated the neuroprotective effects of MV in a model of focal cerebral ischemia. Male C57BL/6J mice were subjected to middle cerebral artery occlusion/reperfusion (MCAO/R) as an in vivo model of cerebral ischemia-reperfusion injury (CIRI), while U87 cells were subjected to oxygen-glucose deprivation/reoxygenation (OGD/R) to simulate CIRI in vitro. MV administration was found to reduce mortality, infarct volume, cerebral edema, and alleviate neurological deficits in these I/R mice. Furthermore, MV mitigated cerebral I/R injury by decreasing oxidative stress markers, such as reactive oxygen species (ROS) and malondialdehyde (MDA), while enhancing superoxide dismutase (SOD) levels. Gene Set Enrichment Analysis (GSEA) of the KEGG pathway revealed that most differentially expressed genes (DEGs) were involved in the Toll-like receptor/NF-κB/TNF/apoptosis signaling pathway. These findings were confirmed by real-time PCR, western blotting, immunohistochemistry, and immunofluorescence co-localization which demonstrated that MV reduced astrocyte inflammatory responses by inhibiting cytokine secretion associated with the TLR4/TRADD pathway. Additionally, MV protected neurons from apoptosis, as supported by TUNEL, Nissl, and HE staining. In conclusion, MV attenuates astrocyte inflammation and exerts neuroprotective effects following cerebral I/R injury, likely through suppression of the TLR4/TRADD signaling pathway.

Buyang huanwu decoction inhibits the activation of the RhoA/Rock2 signaling pathway through the phenylalanine metabolism pathway, thereby reducing neuronal apoptosis following cerebral ischemia-reperfusion injury

ETHNOPHARMACOLOGICAL RELEVANCE

Buyang Huanwu Decoction (BYHWD) exerts its anti-cerebral ischemia effects through multiple pathways and targets, although its specific mechanisms remain unclear.

AIM OF THE STUDY

Ultra-performance liquid chromatography-quadrupole time-of-flight tandem mass spectrometry (UPLC-QTOF-MS) metabolomics and other methods were employed to investigate the role of BYHWD in inhibiting neuronal apoptosis following cerebral ischemia-reperfusion by modulating the RhoA/Rock2 pathway.

METHODS

A rat model of exhaustion swimming combined with middle cerebral artery occlusion (ES + I/R) was established to evaluate the intervention effects of Buyang Huanwu Decoction on cerebral ischemia-reperfusion. This was assessed using neurological function scores, Qi deficiency and blood stasis syndrome scores, HE staining, Nissl staining and TT staining. Differential metabolites and metabolic pathways associated with cerebral ischemia-reperfusion were identified using UPLC-QTOF-MS metabolomics, with key differential metabolites validated through ELISA. Molecular docking techniques were employed to predict interactions between the key differential metabolite, hippuric acid, and its primary downstream pathways. Finally, the levels of neurocellular apoptosis, as well as key molecules in the RhoA/Rock2 signaling pathway and the mitochondrial apoptosis pathway, were measured.

RESULTS

The results indicated that the primary differential metabolites associated with BYHWD's protective effects against ischemia-reperfusion injury were hippuric acid, lysophosphatidic acid, and lysophosphatidylethanolamine, with the main metabolic pathway being phenylalanine metabolism. Molecular docking studies demonstrated that malonic acid exhibited a strong affinity for proteins related to the RhoA/Rock2 signaling pathway and the mitochondrial apoptosis pathway.Furthermore, we found that BYHWD treatment significantly decreased the apoptosis rate of cells following cerebral ischemia-reperfusion and inhibited the expression of key molecules in both the RhoA/Rock2 signaling pathway and the mitochondrial apoptosis pathway in brain tissue.

CONCLUSION

BYHWD ameliorated brain tissue injury after cerebral ischemia/reperfusion in rats with qi deficiency and blood stasis. The underlying mechanism may involve BYHWD's inhibition of the RhoA/Rock2 signaling pathway activation through modulation of the phenylalanine metabolism pathway, thereby reducing neuronal apoptosis mediated by the mitochondrial apoptosis pathway.

A systematic UHPLC-Q-TOF-MS/MS-based strategy for analysis of chemical constituents and related in vivo metabolites of Buyang Huanwu decoction

ETHNOPHARMACOLOGICAL RELEVANCE

Buyang Huanwu Decoction (BYHWD), a traditional Chinese medicine, is one of the classic prescriptions for the treatment of ischemic stroke in clinical practice. It has the effects of tonifying qi, activating blood circulation, and promoting meridian circulation. However, its chemical analysis has not been clarified, which greatly hinders its further clinical application. Therefore, it is necessary to clarify the chemical constituents and metabolites profile of BYHWD in vivo.

AIM OF THE STUDY

Characterizing the chemical basis of BYHWD in vitro, and combing studies of related metabolism in vivo to screen out the potential active components of BYHWD with pharmacological effects in vivo.

MATERIALS AND METHODS

Twelve male rats weighed 200 ± 20 each were selected for the experiments. According to the fragmentation of different structural types of components and diagnostic ions, UHPLC-Q-TOF-MS/MS was used to classify and clarify the unknown components of BYHWD and identify the material basis of BYHWD in vitro. Then, rat plasma, tissues, feces, and urine were collected for analysis. Based on the similarity of MS responses (accurate molecular weight and secondary fragmentation) and chromatographic behavior (retention time), the in vivo prototype and metabolites were analyzed. Through the phase I and phase II metabolism law, a metabolite library was established to analyze the prototype-matched metabolites.

RESULTS

A total of 121 in vitro compounds and 55 in vivo prototypes of BYHWD were identified, corresponding to 123 matched prototypes. It was mainly composed of flavonoids, triterpene saponins, nucleosides and lactones both in vitro and in vivo. Quercetin, ligustilide, astragaloside IV, calycosin, paeoniflorin and ferulic acid were the main prototypes and metabolites in plasma and urine.

CONCLUSION

Quercetin, ligustilide, astragaloside IV, calycosin, paeoniflorin and ferulic acid were the main active ingredients of BYHWD.

Buyang huanwu decoction alleviates stroke-induced immunosuppression in MCAO mice by reducing splenic T cell apoptosis triggered by AIM2 inflammasome

ETHNOPHARMACOLOGICAL RELEVANCE

Ischemic stroke is a serious disabling and fatal disease that places a heavy burden on the world. Stroke induces a state of systemic immunosuppression that is strongly associated with an increased risk of infection and severe outcomes. Buyang Huanwu Decoction (BYHWD) is an ancient Chinese traditional formula with a good clinical and experimental basis. However, the role of BYHWD on post-stroke immunomodulation, especially immunosuppression, is unclear.

AIM OF THE STUDY

The aim of this study was to investigate the pharmacological mechanism of BYHWD to alleviate ischemic stroke by analyzing splenic T cells apoptosis triggered by the AIM2 inflammasome activation cascade.

MATERIALS AND METHODS

An ischemic stroke model in C57BL/6 J mice was constructed using the MCAO method. The mNSS test and the hanging wire test were conducted to evaluate neurological impairment in mice. Histopathological damage was visualized by Nissl staining and HE staining. The protective effects of BYHWD on the spleen were determined by splenic index and spleen HE staining. The inhibition of AIM2 inflammasome cascade by BYHWD were explored through immunofluorescence (IF), flow cytometry, enzyme-linked immunosorbent assay (ELISA) and quantitative reverse transcription polymerase chain reaction (qRT-PCR). Flow cytometry was used to assess the apoptosis of splenic T cells.

RESULTS

BYHWD significantly reduced infarct size, improved neurological function scores, and alleviated histopathological damage in middle cerebral artery occlusion (MCAO) mice. At the same time, BYHWD salvaged spleen atrophy. BYHWD significantly ameliorated apoptosis of splenic T lymphocytes. Key proteins and factors in the AIM2/IL-1β/FasL/Fas axis are effectively inhibited from expression after BYHWD treatment.

CONCLUSION

It is the first study to demonstrate that BYHWD can improve stroke-induced immunosuppression by down-regulating Fas-dependent splenic T-cell apoptosis triggered by peripheral AIM2 inflammasome-driven signaling cascade.

Buqi Huoxue Tongnao prescription protects against chronic cerebral hypoperfusion via regulating PI3K/AKT and LXRα/CYP7A1 signaling pathways

BACKGROUND

Chronic cerebral hypoperfusion (CCH) has been confirmed as one of the pathogenesis underlying vascular cognitive impairment. A series of pathological changes, including inflammation, oxidative stress, and apoptosis, are involved in this pathophysiology and contribute to cognitive impairment and neuropathological alterations. The traditional Chinese medicine (TCM) of Buqi Huoxue Tongnao (BQHXTN) prescription possesses a remarkable clinical efficacy for treating patients with CCH, but still lacks a scientific foundation for its pharmacological mechanisms.

PURPOSE

To investigate the role and underlying mechanism of the effects of BQHXTN on CCH both in vitro and in vivo.

METHODS

In this study, we established a two-vessel occlusion (2-VO) induced CCH model in Sprague-Dawley rats, an oxygen-glucose deprivation model in BV2 cells, and a steatosis cell model in L02 cells to reveal the underlying mechanisms of BQHXTN by behavioral test, histopathological analysis and the detection of pro-inflammatory cytokine, apoptotic factors and reactive oxide species. Donepezil hydrochloride and Buyang Huanwu decoction were used as positive drugs.

RESULTS

Compared with the 2-VO group, BQHXTN treatment at three doses significantly enhanced the memory and learning abilities in the Y-maze and novel object recognition tests. The hematoxylin-eosin staining indicated that BQHXTN protected against hippocampal injury induced by CCH. Of note, in both in vivo and in vitro experiments, BQHXTN prominently inhibited the production of IL-1β, TNF-α, cleaved-caspase 3, and iNOS by regulating the PI3K/AKT pathway, consequently exerting anti-inflammatory, anti-apoptotic, and antioxidant effects. Moreover, it provided the first initial evidence that BQHXTN treatment mitigated dyslipidemia by increasing the LXRα/CYP7A1 expression, thereby delaying the neuropathological process.

CONCLUSION

In summary, these findings firstly revealed the pharmacodynamics and mechanism of BQHXTN, that is, BQHXTN could alleviate cognitive impairment, neuropathological alterations and dyslipidemia in CCH rats by activating PI3K/AKT and LXRα/CYP7A1 signaling pathways, as well as providing a TCM treatment strategy for CCH.

Glycosides of Buyang Huanwu decoction inhibits inflammation associated with cerebral ischemia-reperfusion via the PINK1/Parkin mitophagy pathway

ETHNOPHARMACOLOGICAL RELEVANCE

A classic stroke formula is Buyang Huanwu Decoction (BYHWD), Glycosides are the pharmacological components found in BYHWD, which are utilized for the prevention and management of cerebral ischemia-reperfusion (CIR), as demonstrated in a previous study. Its neuroprotective properties are closely related to its ability to modulate inflammation, but its mechanism is as yet unclear.

AIM OF THE STUDY

A research was undertaken to investigate the impact of glycosides on the inflammation of CIR through the PTEN-induced putative kinase-1 (PINK1)/Parkin mitophagy pathway.

MATERIALS AND METHODS

Analyzing glycosides containing serum components was performed with ultra-performance liquid chromatography-quadrupole-time of flight-mass spectrometry (UPLC-Q-TOF-MS). Glycosides were applied to rat of Middle cerebral artery occlusion/reperfusion (MCAO/R) model and primary neural cell of Oxygen glucose deprivation/reperfusion (OGD/R) model. The neuroprotective effect and the regulation of mitophagy of glycosides were evaluated through neural damage and PINK1/Parkin mitophagy activation. Moreover, the assessment of the relationship between glycosides regulation of mitophagy and its anti-inflammatory effects subsequent to mitophagy blockade was conducted by examining neural damage, PINK1/Parkin mitophagy activation, and levels of pyroptosis.

RESULTS

(1) It was observed that the administration of glycosides resulted in a decrease in neurological function scores, a reduction in cerebral infarction volume, an increase in mitochondrial autophagosome, and the maintenance of a high expression status of light chain 3 (LC3) II/LC3Ⅰ protein. Additionally, there was a significant inhibition of p62 protein expression and an enhancement of PINK1 and Parkin protein expression. Furthermore, it was found that the effect of glycosides at a dosage of 0.128 g · kg-1 was significantly superior to that of glycosides at a dosage of 0.064 g · kg-1. Notably, the neuroprotective effect and inhibition of pyroptosis protein of glycosides at a dosage of 0.128 g · kg-1 were attenuated when mitochondrial autophagy was blocked. (2) Glycosides repaired cellular morphological damage, enhanced cell survival, and reduced Lactate dehydrogenase (LDH) leakage, with glycosides (2.36 μg·mL-1 and 4.72 μg·mL-1) neuronal protection being the strongest. Glycosides (4.72 μg·mL-1) maintained LC3II/LC3Ⅰ protein high expression state, inhibited p62 protein expression, and promoted PINK1 and Parkin protein expression, which was stronger than glycosides (2.36 μg·mL-1). The blockade of mitophagy resulted in a reduction of neuroprotection and inhibition of pyroptosis protein exerted by glycosides.

CONCLUSION

Glycosides demonstrate the ability to hinder inflammation through the activation of the PINK1/Parkin mitophagy pathway, thereby leading to subsequent neuroprotective effects on CIR.

Novel Multi-Antioxidant Approach for Ischemic Stroke Therapy Targeting the Role of Oxidative Stress

Stroke is a major contributor to global mortality and disability. While reperfusion is essential for preventing neuronal death in the penumbra, it also triggers cerebral ischemia-reperfusion injury, a paradoxical injury primarily caused by oxidative stress, inflammation, and blood-brain barrier disruption. An oxidative burst inflicts marked cellular damage, ranging from alterations in mitochondrial function to lipid peroxidation and the activation of intricate signalling pathways that can even lead to cell death. Thus, given the pivotal role of oxidative stress in the mechanisms of cerebral ischemia-reperfusion injury, the reinforcement of the antioxidant defence system has been proposed as a protective approach. Although this strategy has proven to be successful in experimental models, its translation into clinical practice has yielded inconsistent results. However, it should be considered that the availability of numerous antioxidant molecules with a wide range of chemical properties can affect the extent of injury; several groups of antioxidant molecules, including polyphenols, carotenoids, and vitamins, among other antioxidant compounds, can mitigate this damage by intervening in multiple signalling pathways at various stages. Multiple clinical trials have previously been conducted to evaluate these properties using melatonin, acetyl-L-carnitine, chrysanthemum extract, edaravone dexborneol, saffron, coenzyme Q10, and oleoylethanolamide, among other treatments. Therefore, multi-antioxidant therapy emerges as a promising novel therapeutic option due to the potential synergistic effect provided by the simultaneous roles of the individual compounds.