Piceatannol-3'-O-β-D-glucopyranoside attenuates colistin-induced neurotoxicity by suppressing oxidative stress via the NRF2/HO-1 pathway

Piceatannol-3'-O-β-D-glucopyranoside inhibits neuroexcitotoxicity and ferroptosis through NMDAR/NRF2/BACH1/ACSL4 pathway in acute ischemic stroke

BACKGROUND

Neuronal protection is a well-established method of acute ischemic stroke (AIS) treatment. The pharmacodynamic effect of Piceatannol-3'-O-β-D-glucopyranoside (Chinese name: Hartigan, QZZG) on AIS has been reported, but the molecular mechanism of this effect remains unknown.

PURPOSE

The purpose of this study is to elucidate the pharmacodynamic effects and mechanisms of QZZG in the treatment of AIS.

METHODS

A combined network pharmacology and metabolomics approach was used to predict the key targets and pathways of QZZG in the treatment of AIS and to elucidate the mechanism of QZZG through experimental validation.

RESULTS

In this study, QZZG improved histopathologic features and reduced infarct volume and neurologic deficit scores. Integrated network pharmacology and metabolomics revealed that QZZG may protect neurons by regulating glutamate and its receptors, and that glutamate is closely related to NMDAR1, NRF2, and Caspase-3. Pathway analysis results suggested that NMDAR-mediated Ca2+ inward flow is one of the critical pathways. In terms of neuroexcitotoxicity QZZG inhibited glutamate content, reduced Ca2+ inward flow, protected mitochondrial function, and reduced ROS, as well as being able to effectively inhibit the expression of NMDAR1, Caspase-3, Bax, and promote the expression of Bcl-2, NMDAR2A. In terms of ferroptosis QZZG promoted NRF2, HO-1, GPX4 and nuclear-NRF2, inhibited the expression of BACH1 and ACSL4, and suppressed Fe2+ accumulation and lipid peroxidation. Silencing of BACH1 resulted in elevated expression of NRF2 and decreased expression of ACSL4, which inhibited the sensitivity of neurons to ferroptosis. QZZG was able to further increase NRF2 expression under conditions of silencing BACH1. QZZG induced NRF2 and inhibited BACH1, ACSL4 was inhibited by ML385, and inhibition of NRF2 induced the expression of BACH1 and ACSL4, QZZG protects neurons in an NRF2-dependent manner.

CONCLUSION

In summary, QZZG inhibited neuroexcitotoxicity and ferroptosis by regulating the NMDAR/NRF2/BACH1/ACSL4 pathway. The study provided a relatively novel perspective on the mechanism of traditional Chinese medicine (TCM) treatment of the disease.

Bufalin alleviates inflammatory response and oxidative stress in experimental severe acute pancreatitis through activating Keap1-Nrf2/HO-1 and inhibiting NF-κB pathways

Severe acute pancreatitis (SAP) is a prevalent acute inflammatory disease that is clinically manifested by systemic inflammation dysregulation, resulting in a significantly elevated mortality rate. Bufalin has been verified to have potent pharmacological properties, including analgesic, anti-tumor and anti-inflammatory effects. However, it remains unclear whether bufalin inhibits SAP. Thus, we aim to explore the impact of bufalin in SAP rats and to evaluate the potential mechanisms of action. In addition to analyzing serum biochemistry and pancreatic tissue pathology, we elucidated its mechanisms of action through enzyme-linked immunosorbent assay (ELISA), immunohistochemical analysis, Western blot, and quantitative real-time PCR. The results demonstrated that bufalin dose-dependently reversed the elevation of serum Amylase (Amy) and Lipase (LPS) levels in SAP rats, alleviating pancreatic tissue pathological damage. Bufalin exhibited potent antioxidant effects by reducing malondialdehyde (MDA) levels, decreasing Superoxide dismutase (SOD) and glutathione(GSH) consumption, inhibiting the interaction of Keap1-Nrf2, and increasing HO-1 expression. Furthermore, bufalin inhibited TNF-α, IL-6, IL-1β, p-NF-κB-p65, p-IκBα, and NF-κB-p65 expression, while enhancing IκBα expression, ultimately confirming its anti-inflammatory effects on SAP. In summary, our findings suggest that bufalin exerts anti-inflammatory and antioxidant actions in NaT-SAP rats by inhibiting NF-κB and activating the Keap1-Nrf2/HO-1 pathway. This study represents the inaugural application of bufalin in NaT-induced SAP rats, indicating its potential as an effective therapeutic agent for SAP patients.

Unraveling Neurotoxicity Discrepancies: Comparative In vitro and In vivo Analysis of Colistin and Polymyxin B and the Underlying Mechanisms

Polymyxins, including colistin and polymyxin B, are the final resort against Gram-negative bacterial infections. However, its clinical application is restricted due to concerns related to neurotoxicity. Despite the similar antibacterial spectrum and mode of action shared between colistin and polymyxin B, there is still a lack of definitive evidence to support the idea that their neurotoxicity profiles are identical. To comprehensively compare the neurotoxicity between colistin and polymyxin B both in vivo and in vitro and establish a theoretical foundation to guide the rational use of polymyxins within clinical settings. in vitro experiments simulated nerve damage by exposing N2a and RSC96 cells to colistin and polymyxin B. The evaluation of nerve injury included assessments of cell viability and apoptosis. To discern the variance in the mechanisms of nerve injury between colistin and polymyxin B, oxidative stress levels were examined, such as SOD, CAT, GSH, and malondialdehyde (MDA). In in vivo experiments, a rat nerve injury model was created by intraventricular injections of colistin and polymyxin B, respectively. The impact of these drugs on brain injury in rats, particularly within the hippocampus and medulla oblongata, was measured using HE and Nissl staining. The potential influence of polymyxins on the ferroptosis pathway was evaluated by assessing LPO and Fe2+ levels and the degree of mitochondrial impairment. At equivalent doses, colistin demonstrated a reduced level of neurotoxicity compared to polymyxin B, both in vitro and in vivo. in vitro experiments revealed greater cell viability and a lower apoptosis rate after colistin treatment than after polymyxin B treatment. This variance in outcomes could be attributed to the comparatively lower levels of oxidative stress associated with colistin administration. In a rat model, nerve injury resulted in observable damage to both the hippocampus and the medulla oblongata. A comprehensive assessment of the extent of damage in the CA1 to CA4 regions of the hippocampus, and the solitary tract nucleus of the medulla oblongata underscored that the neurotoxic effects of colistin remained milder compared to those elicited by polymyxin B. Even when evaluated at equivalent multiples of clinically recommended doses, colistin exhibited lower neurotoxicity in vivo than polymyxin B. For the first time, this study demonstrated the role of ferroptosis in polymyxin B-induced nerve damage. The activation levels observed within the ferroptosis pathway due to polymyxin B exceeded those triggered by colistin. Colistin exhibited a marked reduction in neurotoxicity compared to polymyxin B, evident in both the equivalent and clinically recommended doses. These findings suggest that, from the perspective of neurotoxicity, colistin presents a more favorable option for clinical use.

Piceatannol Protects Sperm from Cryopreservation Damage by Modulating the Keap1-Nrf2/ARE Signaling Pathway

The purpose of this study was to explore the mechanism of action of Piceatannol (PIC) in attenuating oxidative damage to sperm during cryopreservation. Semen samples were collected and homogenized into six equal parts for freeze-thawing experiments. Four different concentrations of PIC were utilized as cryoprotectants during the freeze-thawing process, maintaing a semen to PIC ratio of 1:1, while sperm motility after freezing and thawing was analyzed using computer-assisted sperm analysis (CASA). Sperm plasma membrane integrity was assessed via the hypo-osmotic swelling (HOS) test. The levels of reactive oxygen species (ROS), superoxide dismutase (SOD) and total antioxidant capacity (T-AOC) activities, long with the ability to scavenge sperm malondialdehyde (MDA), were examined in sperm following the addition of PIC. Quantitative real-time PCR (qRT-PCR) was performed to detect the expression levels of Keap1, Nrf2, GCLC, GCLM, and HMOX1 in sperm. The mechanism by which PIC protects sperm during cryopreservation from oxidative stress damage was further verified. Treatment with PIC at a dose of 5.0 μmol/L significantly improved both sperm motility and viability while effectively reducing ROS levels in frozen sperm. Additionally, the integrity of the sperm plasma membrane was significantly enhanced. Furthermore, the expression level of Keap1 was significantly reduced, whereas the expression levels of GCLC, GCLM, HMOX1, and Nrf2 were significantly increased (p < 0.05) after the addition of PIC. Notably, a significant attenuation of sperm motility and viability was observed in this treatment group when PIC treatment was accompanied by the addition of an Nrf2 inhibitor, resulting in a significant elevation of ROS levels. The finding that PIC modulates ROS in frozen sperm via the Keap1-Nrf2/ARE pathway thereby enhancing sperm viability levels after freezing and thawing provides a novel approach to optimize semen cryopreservation.

Colistin Induces Oxidative Stress and Apoptotic Cell Death through the Activation of the AhR/CYP1A1 Pathway in PC12 Cells

Colistin is commonly regarded as the "last-resort" antibiotic for combating life-threatening infections caused by multidrug-resistant (MDR) gram-negative bacteria. Neurotoxicity is a potential adverse event associated with colistin application in clinical settings, yet the exact molecular mechanisms remain unclear. This study examined the detrimental impact of colistin exposure on PC12 cells and the associated molecular mechanisms. Colistin treatment at concentrations of 0-400 μM decreased cell viability and induced apoptotic cell death in both time- and concentration-dependent manners. Exposure to colistin triggered the production of reactive oxygen species (ROS) and caused oxidative stress damage in PC12 cells. N-acetylcysteine (NAC) supplementation partially mitigated the cytotoxic and apoptotic outcomes of colistin. Evidence of mitochondrial dysfunction was observed through the dissipation of membrane potential. Additionally, colistin treatment upregulated the expression of AhR and CYP1A1 mRNAs in PC12 cells. Pharmacological inhibition of AhR (e.g., using α-naphthoflavone) or intervention with the CYP1A1 gene significantly decreased the production of ROS induced by colistin, subsequently lowering caspase activation and cell apoptosis. In conclusion, our findings demonstrate, for the first time, that the activation of the AhR/CYP1A1 pathway contributes partially to colistin-induced oxidative stress and apoptosis, offering insights into the cytotoxic effects of colistin.

The potential role of Tirzepatide as adjuvant therapy in countering colistin-induced nephro and neurotoxicity in rats via modulation of PI3K/p-Akt/GSK3-β/NF-kB p65 hub, shielding against oxidative and endoplasmic reticulum stress, and activation of p-CREB/BDNF/TrkB cascade

Although colistin has a crucial antibacterial activity in treating multidrug-resistant gram-negative bacteria strains; it exhibited renal and neuronal toxicities rendering its use a challenge. Previous studies investigated the incretin hormones either glucose-dependent insulinotropic polypeptide (GIP) or glucagonlike peptide-1 (GLP-1) for their neuroprotective and nephroprotective effectiveness. The present study focused on investigating Tirzepatide (Tirze), a dual GLP-1/GIP agonist, as an adjuvant therapy in the colistin treatment protocol for attenuating its renal and neuronal complications. Rats were divided into; The normal control group, the colistin-treated group received colistin (300,000 IU/kg/day for 7 days; i.p.). The Tirze-treated group received Tirze (1.35 mg/kg on the 1,4,7thdays; s.c.) and daily colistin. Tirze effectively enhanced histopathological alterations, renal function parameters, and locomotor activity in rats. Tirze mechanistically acted via modulating various signaling axes evolved under the insult of phosphatidylinositol 3-kinases (PI3K)/phosphorylated protein kinase-B (p-Akt)/ glycogen synthase kinase (GSK)3-β hub causing mitigation of nuclear factor (NF)-κB (NF-κB) / tumor necrosis factor-α (TNF-α), increment of nuclear factor erythroid 2-related factor 2 (Nrf2)/ glutathione (GSH), downregulation of ER stress-related biomarkers (activation transcription factor 4 (ATF4) and C/EBP homologous protein (CHOP)), antiapoptotic effects coupling with reduction of glial fibrillary acidic protein (GFAP) immunoreactivity and enhancement of phosphorylated c-AMP response element-binding (p-CREB) / brain-derived neurotrophic factor (BDNF)/tyrosine kinase B (TrkB) neuroprotective pathway. Briefly, Tirze exerts a promising role as adjuvant therapy in the colistin treatment protocol for protection against colistin's nephro- and neurotoxicity according to its anti-inflammatory, antioxidant, and antiapoptotic impacts besides its ability to suppress ER stress-related biomarkers.

Prevention of colistin-induced neurotoxicity: a narrative review of preclinical data

Polymyxin E or colistin is an effective antibiotic against MDR Gram-negative bacteria. Due to unwanted side effects, the use of this antibiotic has been limited for a long time, but in recent years, the widespread of MDR Gram-negative bacteria infections has led to its reintroduction. Neurotoxicity and nephrotoxicity are the significant dose-limiting adverse effects of colistin. Several agents with anti-inflammatory and antioxidant properties have been used for the prevention of colistin-induced neurotoxicity. This study aims to review the preclinical studies in this field to prepare guidance for future human studies. The data was achieved by searching PubMed, Scopus, and Google Scholar databases. All eligible pre-clinical studies performed on neuroprotective agents against colistin-induced neurotoxicity, which were published up to September 2023, were included. Finally, 16 studies (ten in vitro and eight in vivo) are reviewed. Apoptosis (in 13 studies), inflammatory (in four studies), and oxidative stress (in 14 studies) pathways are the most commonly reported pathways involved in colistin-induced neurotoxicity. The assessed compounds include non-herbal (e.g., ascorbic acid, rapamycin, and minocycline) and herbal (e.g., curcumin, rutin, baicalein, salidroside, and ginsenoside) agents. Besides these compounds, some other measures like transplantation of mitochondria and the use of nerve growth factor and mesenchymal stem cells could be motivating subjects for future research. Based on the data from experimental (in vitro and animal) studies, a combination of colistin with neuroprotective agents could prevent or decrease colistin-induced neurotoxicity. However, well-designed randomized clinical trials and human studies are essential for demonstrating efficacy.

Extracts and Scirpusin B from Recycled Seeds and Rinds of Passion Fruits (Passiflora edulis var. Tainung No. 1) Exhibit Improved Functions in Scopolamine-Induced Impaired-Memory ICR Mice

In this paper, the seeds and rinds of passion fruit, which are the agricultural waste of juice processing, were recycled to investigate their biological activities for sustainable use. De-oiled seed powders (S) were successively extracted by refluxing 95% ethanol (95E), 50E, and hot water (HW), respectively, to obtain S-95EE, S-50EE, and S-HWE. Dried rind powders were successively extracted by refluxing HW and 95E to obtain rind-HWE and rind-95EE, respectively. S-50EE and S-95EE showed the most potent extracts, such as anti-amyloid-β1-42 aggregations and anti-acetylcholinesterase inhibitors, and they exhibited neuroprotective activities against amyloid-β25-35-treated or H2O2-treated SH-SY5Y cells. Scirpusin B and piceatannol were identified in S-95EE, S-50EE, and rind-HWE, and they showed anti-acetylcholinesterase activity at 50% inhibitory concentrations of 62.9 and 258.9 μM, respectively. Daily pretreatments of de-oiled seed powders and rind-HWE (600 mg/kg), S-95EE, and S-50EE (250 mg/kg) or scirpusin B (40 mg/kg) for 7 days resulted in improved learning behavior in passive avoidance tests and had significant differences (p < 0.05) compared with those of the control in scopolamine-induced ICR mice. The seeds and rinds of passion fruit will be recycled as materials for the development of functional foods, promoting neuroprotection and delaying the onset of cognitive dysfunctions.

Inhibition of Acetylcholinesterase and Amyloid-β Aggregation by Piceatannol and Analogs: Assessing In Vitro and In Vivo Impact on a Murine Model of Scopolamine-Induced Memory Impairment

Currently, no drug is effective in delaying the cognitive impairment of Alzheimer's disease, which ranks as one of the top 10 causes of death worldwide. Hydroxylated stilbenes are active compounds that exist in fruit and herbal plants. Piceatannol (PIC) and gnetol (GNT), which have one extra hydroxyl group in comparison to resveratrol (RSV), and rhapontigenin (RHA) and isorhapontigenin (isoRHA), which were metabolized from PIC in vivo and contain the same number of hydroxyl groups as RSV, were evaluated for their effects on Alzheimer's disease-associated factors in vitro and in animal experiments. Among the five hydroxylated stilbenes, PIC was shown to be the most active in DPPH radical scavenging and in inhibitory activities against acetylcholinesterase and amyloid-β peptide aggregations, with concentrations for half-maximal inhibitions of 40.2, 271.74, and 0.48 μM. The different interactions of the five hydroxylated stilbenes with acetylcholinesterase or amyloid-β were obtained by molecular docking. The scopolamine-induced ICR mice fed with PIC (50 mg/kg) showed an improved learning behavior in the passive avoidance tests and had significant differences (p < 0.05) compared with those in the control group. The RHA and isoRHA at 10 μM were proven to stimulate neurite outgrowths in the SH-SY5Y cell models. These results reveal that nutraceuticals or functional foods containing PIC have the potential for use in the treatment of neurodegenerative disorders.