Alpinia oxyphylla Miq extract reduces cerebral infarction by downregulating JNK-mediated TLR4/T3JAM- and ASK1-related inflammatory signaling in the acute phase of transient focal cerebral ischemia in rats

Neuroprotective effects of Gastrodia elata Blume on promoting M2 microglial polarization by inhibiting JNK/TLR4/T3JAM/NF-κB signaling after transient ischemic stroke in rats

Background

Gastrodia elata Blume, also called Tian Ma (TM), has been used to treat stroke for centuries. However, its effects on inflammation in acute cerebral ischemic injury and underlying mechanisms involved in microglial polarization remain unknown. The present study explored the effects of the TM extract on the modulation of microglial M1/M2 polarization 2 days after transient cerebral ischemia.

Methods

Male Sprague Dawley rats were intracerebroventricularly administered with 1% dimethyl sulfoxide 25 min before cerebral ischemia and subsequently intraperitoneally administered 0.25 g/kg (DO + TM-0.25 g), 0.5 g/kg (DO + TM-0.5 g), or 1 g/kg (DO + TM-1 g) of the TM extract after cerebral ischemia onset.

Results

DO + TM-0.5 g and DO + TM-1 g treatments downregulated the following: phospho-c-Jun N-terminal kinase (p-JNK)/JNK, tumor necrosis factor (TNF) receptor-associated factor 3 (TRAF3), TRAF3-interacting JNK-activating modulator (T3JAM), p-nuclear factor-kappa B p65 (p-NF-κB p65)/NF-κB p65, ionized calcium-binding adapter molecule 1 (Iba1), CD86, TNF-α, interleukin (IL)-1β, and IL-6 expression and toll-like receptor 4 (TLR4)/Iba1, CD86/Iba1, and p-NF-κB p65/Iba1 coexpression. These treatments also upregulated IL-10, nerve growth factor, and vascular endothelial growth factor A expression and YM-1/2/Iba1 and IL-10/neuronal nuclei coexpression in the cortical ischemic rim. The JNK inhibitor SP600125 exerted similar treatment effects as the DO + TM-0.5 g and DO + TM-1 g treatments.

Conclusion

DO + TM-0.5 g and DO + TM-1 g/kg treatments attenuate cerebral infarction by inhibiting JNK-mediated signaling. TM likely exerts the neuroprotective effects of promoting M1 to M2 microglial polarization by inhibiting JNK/TLR4/T3JAM/NF-κB-mediated signaling in the cortical ischemic rim 2 days after transient cerebral ischemia.

Recent Research Progress on the Chemical Constituents, Pharmacology, and Pharmacokinetics of Alpinae oxyphyllae Fructus

Alpinae oxyphyllae fructus (AOF), the dried mature fruit of Alpinia oxyphylla Miquel of the Zingiberaceae family, shows many special pharmacological effects. In recent years, there has been an abundance of research results on AOF. In this paper, the new compounds isolated from AOF since 2018 are reviewed, including terpenes, flavonoids, diarylheptanoids, phenolic acid, sterols, alkanes, fats, etc. The isolation methods that were applied include the microwave-assisted method, response surface method, chiral high-performance liquid chromatography-multiple reaction monitoring-mass spectrometry (HPLC-MRM-MS) analytical method, ultra-high-performance liquid chromatography-quadrupole-electrostatic field orbitrap high-resolution mass spectrometry (UPLC-Orbitrap-HRMS) method, ultra-high-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method, hot water leaching method, ethanol leaching method, and so on. Additionally, the pharmacological effects of AOF found from 2018 to 2024 are also summarized, including neuroprotection, regulation of metabolic disorders, antioxidant activity, antiapoptosis, antiinflammatory activity, antidiabetic activity, antihyperuricemia, antiaging, antidiuresis, immune regulation, anti-tumor activity, renal protection, hepatoprotection, and anti-asthma. This paper provides a reference for further research on AOF.

Natural herbal extract roles and mechanisms in treating cerebral ischemia: A systematic review

Background

Stroke has been the focus of medical research due to its serious consequences and sequelae. Among the tens of millions of new stroke patients every year, cerebral ischemia patients account for the vast majority. While cerebral ischemia drug research and development is still ongoing, most drugs are terminated at preclinical stages due to their unacceptable toxic side effects. In recent years, natural herbs have received considerable attention in the pharmaceutical research and development field due to their low toxicity levels. Numerous studies have shown that natural herbs exert actions that cannot be ignored when treating cerebral ischemia.

Methods

We reviewed and summarized the therapeutic effects and mechanisms of different natural herbal extracts on cerebral ischemia to promote their application in this field. We used keywords such as "natural herbal extract," "herbal medicine," "Chinese herbal medicine" and "cerebral ischemia" to comprehensively search PubMed, ScienceDirect, ScienceNet, CNKI, and Wanfang databases, after which we conducted a detailed screening and review strategy.

Results

We included 120 high-quality studies up to 10 January 2024. Natural herbal extracts had significant roles in cerebral ischemia treatments via several molecular mechanisms, such as improving regional blood flow disorders, protecting the blood-brain barrier, and inhibiting neuronal apoptosis, oxidative stress and inflammatory responses.

Conclusion

Natural herbal extracts are represented by low toxicity and high curative effects, and will become indispensable therapeutic options in the cerebral ischemia treatment field.

Oxyberberine protects middle cerebral artery occlusion triggered cerebral injury through TLR4/NLRP3 pathway in rats

Cerebral ischemia is a life-threatening health concern that leads to severe neurological complications and fatalities worldwide. Although timely intervention with clot-removing agents curtails serious post-stroke neurological dysfunctions, no effective neuroprotective intervention is available for addressing post-recanalization neuroinflammation. Herein, for the first time we studied the effect of oxyberberine (OBB), a derivative of berberine, on transient middle cerebral artery occlusion (MCAO)-generated neurological consequences in Sprague-Dawley rats. The MCAO-operated rats exhibited significant somatosensory and sensorimotor dysfunctions in adhesive removal, foot fault, paw whisker, and rotarod assays at 1 and 3 days post-surgery. These MCAO-generated neurological deficits were prevented in OBB-treated (50 and 100 mg/kg) rats, and also coincided with a smaller infarct area (in 2,3,5-triphenyl tetrazolium chloride staining) and decreased neuronal death (in cresyl violet staining) in the ipsilateral hemisphere of these animals. The immunostaining of neuronal nuclear protein (NeuN) and glial-fibrillary acidic protein (GFAP) also echoes the neuroprotective nature of OBB. The increased expression of neuroinflammatory and blood-brain barrier tight junction proteins like toll-like receptor 4 (TLR4), TRAF-6, nuclear factor kappa B (NF-κB), pNF-κB, nNOS, ASC, and IKBα in the ipsilateral part of MCAO-operated rats were restored to normal following OBB treatment. We also observed the decline in plasma levels/mRNA transcription of TNF-α, IL-1β, NLRP3, IL-6, and matrix metalloproteinase-9 and increased expression of occludin and claudin in OBB-treated rats. These outcomes imply that OBB may prevent the MCAO-induced neurological consequences and neuroinflammation by interfering with TLR4 and NLRP3 signaling in rats.

Piceatannol improved cerebral blood flow and attenuated JNK3 and mitochondrial apoptotic pathway in a global ischemic model to produce neuroprotection

Cerebral ischemia is one of the leading causes of death and disability worldwide. The only FDA-approved treatment is recanalization with systemic tissue plasminogen activators like alteplase, although reperfusion caused by recanalization can result in neuroinflammation, which can cause brain cell apoptosis. Therefore, after an ischemic/reperfusion injury, interventions are needed to minimize the neuroinflammatory cascade. In the present study, piceatannol (PCT) was studied for its neuroprotective efficacy in a rat model of global ischemic injury by attenuating c-Jun N-terminal kinase 3 (JNK3) downstream signaling. PCT is a resveratrol analog and a polyphenolic stilbenoid naturally occurring in passion fruit and grapes. The neuroprotective efficacy of PCT (1, 5, 10 mg/kg) in ischemic conditions was assessed through pre- and post-treatment. Cerebral blood flow (CBF) and tests for functional recovery were assessed. Protein and gene expression were done for JNK3 and other inflammatory markers. A docking study was performed to identify the amino acid interaction. The results showed that PCT improved motor and memory function as measured by a functional recovery test believed to be due to an increase in cerebral blood flow. Also, the caspase signaling which promotes apoptosis was found to be down-regulated; however, nitric oxide synthase expression was up-regulated, which could explain the enhanced cerebral blood flow (CBF). According to our findings, PCT impeded c-Jun N-terminal kinase 3 (JNK3) signaling by suppressing phosphorylation and disrupting the mitochondrial apoptotic pathway, which resulted in the neuroprotective effect. Molecular docking analysis was performed to investigate the atomic-level interaction of JNK3 and PCT, which reveals that Met149, Leu206, and Lys93 amino acid residues are critical for the interaction of PCT and JNK3. According to our current research, JNK3 downstream signaling and the mitochondrial apoptosis pathway are both inhibited by PCT, which results in neuroprotection under conditions of global brain ischemia. Piceatannol attenuated JNK3 phosphorylation during the ischemic condition and prevented neuronal apoptosis.

Electroacupuncture at the Dazhui and Baihui acupoints and different frequencies (10 and 50 Hz) protects against apoptosis by up-regulating ERK1/2-mediated signaling in rats after global cerebral ischemia

Objectives

This study assessed the effects of electroacupuncture (EA) stimulation at different frequencies at the Dazhui and Baihui acupoints in the subacute phase after transient global cerebral ischemia (GCI).

Materials and Methods

Rats were subjected to GCI for 25 min, followed by reperfusion for 7 days. EA at acupoints was performed at 10, 30, or 50 Hz, 1 day after reperfusion and then once daily for 6 consecutive days.

Results

EA at acupoints at 10 and 50 Hz effectively down-regulated apoptosis in the hippocampal cornu ammonis 1(CA1) area and ameliorated memory deficits. Moreover, EA treatment at 10 and 50 Hz markedly increased phospho (p)-extracellular signal-regulated protein kinase 1/2 (ERK1/2), p-ERK1/2/neuronal nuclei (NeuN), p-cAMP response element-binding protein (CREB)/p-ERK1/2, B-cell lymphoma-2 (Bcl-2)/p-CREB, and X-linked inhibitor of apoptosis protein/NeuN expression levels and decreased Bcl-2 homologous antagonist/killer, second mitochondria-derived activator of caspase/direct inhibitor of apoptosis-binding protein with low pI, cytochrome c, cleaved caspase-3, and apoptosis-inducing factor expression levels. Furthermore, 10-Hz EA treatment effectively increased p-p38 mitogen-activated protein kinase (MAPK), p-p38 MAPK/NeuN, and p-CREB/p-p38 MAPK expression levels. Pretreatment with U0126 (ERK1/2 inhibitor) completely abrogated the effects of 10- and 50-Hz EA treatments on the aforementioned protein expression levels. Similarly, pretreatment with SB203580 (p38 MAPK inhibitor) completely abrogated the effects of 10-Hz treatment on the aforementioned protein expression levels.

Conclusion

The effects of 10- and 50-Hz EA treatments on mitochondria-related apoptosis can be attributed to the activation of ERK1/2/p38 MAPK/CREB/Bcl-2- and ERK1/2/CREB/Bcl-2-mediated signaling, respectively, in the hippocampal CA1 area at 7 days after transient GCI.

Alpinia oxyphylla Miq. volatile oil ameliorates depressive behaviors and inhibits neuroinflammation in CUMS-exposed mice by inhibiting the TLR4-medicated MyD88/NF-κB signaling pathway

This study aimed to explore the antidepressant effect and underlying mechanism of the Alpinia oxyphylla Miq. volatile oil (AOVO) in mice exposed to chronic unpredictable mild stress (CUMS). C57BL/6 mice were grouped and administered with different dosages of AOVO (0.25, 0.50, 1.00, or 2.00 mL/kg body weight, i.g.), TAK242 (a TLR4 inhibitor, 0.75 mg/kg body weight, i.p.), or TAK242 (0.75 mg/kg body weight, i.p.) + AOVO (0.50 mL/kg body weight, i.g.) for 21 days. Depression-like symptoms in the mice were then evaluated through their body weight gain (BW), the open field test (OFT), the sucrose preference test (SPT), the novelty-suppressed feeding test (NSFT), and forced swimming test (FST). The concentrations of interleukin-1β (IL-1β), interleukin-6 (IL-6), tumor necrosis factor α (TNF-α), and 5-hydroxytyrptamine (5-HT) in the mice were determined using ELISA kits. Hematoxylin and eosin (HE) dying were performed for histopathological examination. The expression of inflammatory proteins was assessed through western blotting (WB) and immunofluorescence staining. AOVO was found to improve the behavioral indexes of CUMS-exposed mice behavioral and synergize TAK242 to mitigate both their depressive symptoms and neuroinflammation. Moreover, AOVO was found to inhibit the hippocampal damage, decrease inflammatory cytokines (Reduced IL-1β, IL-6, and TNF-α by 19.97 %, 22.87 %, and 24.13 %, respectively), and downregulate the expression of TLR4/MyD88/NF-κB signaling pathway-related proteins in the hippocampus of CUMS-exposed mice (Reduced TLR4, MyD88, and NF-κB by 46.14 %, 42.48 %, and 38.08 %, respectively). These findings demonstrate that AOVO can ameliorate depressive behaviors and mitigate neuroinflammation in the CUMS-exposed mice via suppressing the TLR4-medicated MyD88/NF-κB signaling pathway.

Neuroprotective Effects of Alpinia oxyphylla Miq against Mitochondria-Related Apoptosis by the Interactions between Upregulated p38 MAPK Signaling and Downregulated JNK Signaling in the Subacute Phase of Cerebral Ischemia-Reperfusion in Rats

Apoptosis in the penumbra region is the major cell death mechanism occurring during ischemia–reperfusion injury’s early phase. Here, we evaluated how the Alpinia oxyphylla Miq (AOM) affects mitochondria-related apoptosis 3 days after transient middle cerebral artery occlusion (MCAo) and examined the mechanisms underlying the regulation of MAPK-mediated mitochondria-related apoptotic signaling in the peri-infarct cortex in rats. The rats were administered the AOM extract intraperitoneally at doses of 0.2[Formula: see text]g/kg (AOM-0.2[Formula: see text]g), 0.4[Formula: see text]g/kg (AOM-0.4[Formula: see text]g), or 0.8[Formula: see text]g/kg (AOM-0.8[Formula: see text]g) at MCAo initiation. The AOM-0.4[Formula: see text]g and AOM-0.8[Formula: see text]g significantly ameliorated apoptotic cell death and considerably downregulated cytochrome c (cyto c) and cleaved caspase-3 immunoreactivity 3 days after reperfusion. Simultaneously, they significantly downregulated cytosolic p-JNK/JNK, cathepsin B/actin, cyto c/actin, Smac/DIABLO/actin, cleaved caspase-3/actin, and AIF/actin and mitochondrial p53/HSP60 and Bax/HSP60 fractions but upregulated cytosolic p-p38 MAPK/p38 MAPK, p-p90RSK/actin, p-Bad/Bad, p-CREB/actin, and XIAP/actin and cytosolic and mitochondrial Bcl-2/Bax and Bcl-xL/Bax fractions in the peri-infarct cortex. Pretreatment with SB203580 — a p38 MAPK inhibitor — completely abrogated the effects of AOM-0.8[Formula: see text]g on the aforementioned protein expression, whereas treatment with SP600125 — a JNK inhibitor — exerted protective effects similar to those of AOM-0.8[Formula: see text]g. Treatment with 0.4 or 0.8[Formula: see text]g/kg AOM has neuroprotective effects against mitochondria-related apoptosis by suppressing cyto c, Smac/DIABLO, and AIF release from the mitochondria to cytosol. The anti-mitochondria related apoptotic effects of the AOM extract are attributable to the interactions between upregulated p38 MAPK/p90RSK-mediated p-Bad and CREB signaling and downregulated JNK/cathepsin B-mediated Bax and p53 signaling in the peri-infarct cortex 3 days after transient MCAo.