Eriodictyol Attenuates MCAO-Induced Brain Injury and Neurological Deficits via Reversing the Autophagy Dysfunction

Sevoflurane-induced regulation of NKCC1/KCC2 phosphorylation through activation of Spak/OSR1 kinase and cognitive impairment in ischemia-reperfusion injury in rats

The occurrence of excitotoxic damage caused by cerebral ischemia-reperfusion (I/R) injury is closely linked to a decrease in central inhibitory function, in which the concentration of chloride inside the cells ([Cl-]i) plays a crucial role. The outflow and inflow of [Cl-]i are controlled by KCC2 and NKCC1, which are cellular cotransporters for K+/Cl- and Na+/K+/Cl-, respectively. NKCC1/KCC2 is regulated by upstream regulators such as SPAK and OSR1, whose activity is influenced by I/R. Sevoflurane is the most commonly used and controversial general anesthetic. To elucidate the impact of sevoflurane on cerebral ischemia-reperfusion (I/R) injury and its underlying mechanism, we investigated its influence on cognitive function and the mechanism of action utilizing a rat model of I/R. By activating the kinase Spak/OSR1, we discovered that I/R damage enhanced the function of NKCC1 and inhibited the function of KCC2, which triggered an imbalance of [Cl-]i concentration, leading to neurological dysfunction and cognitive dysfunction. At the beginning of reperfusion, administration of 1.3 MAC sevoflurane for 3 h increased activation of Spak/OSR1 kinases on day 7 post-perfusion, resulting in an additional dysregulation of NKCC1 and KCC2 activity, which disappeared on day 14. Administration of Closantel, a Spak/OSR1 kinase inhibitor, to animals treated with sevoflurane reverses the additional stimulation. The research revealed that sevoflurane modified the functioning of NKCC1 and KCC2, resulting in cognitive decline by activating Spak/OSR1 kinase. However, this issue could be resolved by inhibiting Spak/OSR1. The research revealed that sevoflurane transiently alters the function of NKCC1 and KCC2, resulting in exacerbating cognitive decline. However, this can be fixed by suppressing Spak/OSR1.

Neuroprotective effects of galectin‑1 on cerebral ischemia/reperfusion injury by regulating oxidative stress

Oxidative stress contributes to the pathology of cerebral ischemia/reperfusion (I/R) injury. Galectin-1 has shown an anti-oxidative stress effect. The present study investigated whether this anti-oxidative stress effect can account for the neuroprotective actions of galectin-1 induced by cerebral I/R injury. A cerebral I/R injury model was created in C57Bl/6 mice by transient occlusion of the middle cerebral artery, after which the mice were treated with galectin-1 for 3 days. Infarct volumes were measured. A rotarod test and neurological deficit score assessment was performed to evaluate the neurological deficits. Oxidative stress was evaluated by measuring the levels of reactive oxygen species (ROS) and lipid peroxidation malondialdehyde (MDA), while the anti-oxidative stress status was assessed by measuring molecules such as catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidation enzyme (GSH-Px) in the ischemic cerebral hemisphere of mice. The inflammatory cytokines, including Interleukin 1 (IL-1), IL-6 and tumor necrosis factor alpha (TNF-α) were measured, and the expression of microglia was evaluated by immunohistochemistry in the ischemic cerebral hemisphere of mice. Galectin-1 treatment ameliorated neurological deficits and reduced infarct volumes in the mice model with cerebral I/R injury. Moreover, it was demonstrated that galectin-1 can significantly alleviate cerebral I/R injury in the ischemic cerebral hemisphere by decreasing the production of ROS and MDA, but increasing the production of CAT, SOD and GSH-Px. Galectin-1 treatment decreased microglia expression, and IL-1, IL-6 and TNF-α levels in the ischemic cerebral hemisphere of mice. Galectin-1 could improve the outcome of cerebral I/R injury by alleviating oxidative stress. Moreover, the neuroprotective effect of galectin-1 in cerebral ischemia could be related to its anti-oxidative stress effect.

Spatholobi caulis: A systematic review of its traditional uses, chemical constituents, biological activities and clinical applications

ETHNOPHARMACOLOGICAL RELEVANCE

Spatholobi caulis (SC), the dried vine stem of Spatholobus suberectus Dunn, is known as Ji Xue Teng in China, and has long been used as traditional Chinese medicine (TCM) to treat anaemia, menstrual abnormalities, rheumatoid arthritis, purpura, etc. AIM OF THE REVIEW: The aim of this review is to provide a systematic and updated summary of the traditional uses, chemical constituents, biological activities and clinical applications of SC. In addition, several suggestions for future research on SC are also proposed.

MATERIALS AND METHODS

Extensive information and data on SC were obtained from electronic databases (ScienceDirect, Web of Science, PubMed, CNKI, Baidu Scholar, Google Scholar, ResearchGate, SpringerLink and Wiley Online). Additional information was collected from Ph.D. and MSc dissertations, published books, and classic material medica.

RESULTS

To date, phytochemical studies have revealed that approximately 243 chemical ingredients have been isolated from SC and identified, including flavonoids, glycosides, phenolic acids, phenylpropanoids, volatile oils, sesquiterpenoids and other compounds. Many studies have indicated that extracts and pure constituents from SC possess a wide spectrum of in vitro and in vivo pharmacological effects, such as anti-tumour, haematopoietic, anti-inflammatory, antidiabetic, antioxidant, antiviral and antibacterial effects, as well as other activities. SC could be applied to the treatment of leukopenia, aplastic anemic, endometriosis, etc. according to the clinical reports. The traditional efficacies of SC is due to the biological functions of its chemical compounds, especially flavonoids. However, research investigating the toxicological effects of SC is relatively limited.

CONCLUSIONS

SC is widely used in TCM formulae and its some traditional efficacies has been confirmed by extensive recent pharmacological and clinical studies. Most the biological activities of the SC may be attributed to flavonoids. However, in-depth studies on the molecular mechanisms of the effective ingredients and extracts of SC are limited. Further systematic studies focusing on pharmacokinetics, toxicology and quality control are needed to ensure the effective and safe application of SC.

VCAM-1+ hUC-MSCs Exert Considerable Neuroprotection Against Cerebral Infarction in Rats by Suppression of NLRP3-Induced Pyroptosis

Mesenchymal stem/stromal cells (MSCs) are spindle-like heterogeneous cell populations with advantageous bidirectional immunomodulatory and hematopoietic support effects. Vascular cellular adhesion molecule-1 (VCAM-1)+ MSCs have been reported to exhibit immunoregulatory and proangiogenic capacities. Here, we studied the effects of VCAM-1+ human umbilical cord (hUC)-MSCs on neuroprotection against cerebral infarction. Sprague-Dawley rats were subjected to middle cerebral artery occlusion (MCAO), and VCAM-1- and VCAM-1+ hUC-MSCs were intravenously injected into the rat 4 h post-MCAO surgery. Thereafter, modified neurological severity scores (mNSS) were determined, and the Morris water maze test, 2,3,5-triphenyltetrazolium chloride (TTC), hematoxylin and eosin (H&E), Nissl, TUNEL staining, and qRT-PCR were conducted. Following induction of oxygen-glucose deprivation/reoxygenation (OGD/R), SH-SY5Y cells were co-cultured with VCAM-1- and VCAM-1+ hUC-MSCs. CCK-8, flow cytometry, ELISA, and western blot analyses were performed in vitro. Compared with VCAM-1- hUC-MSCs, administration of VCAM-1+ hUC-MSCs revealed improved therapeutic efficacy against cerebral infarction in rats, as confirmed by lower mNSS scores and infarct volumes, as well as improved learning and memory capacities. In addition, VCAM-1+ hUC-MSCs exhibited improved efficacy against neurological defects in rats with cerebral infarction, accompanied by inhibition of the NLRP3-mediated inflammatory response. VCAM-1+ hUC-MSC co-culture improved the viability and diminished NLRP3-mediated inflammatory response in OGD/R-treated SH-SY5Y cells. Moreover, NLRP3 overexpression in SH-SY5Y cells prevented the beneficial effects of VCAM-1+ hUC-MSC co-culture. Overall, our findings demonstrated the relevance of VCAM-1+ hUC-MSC-based cytotherapy for preclinical neuroprotection against cerebral infarction.

COVID-19 and Long COVID: Disruption of the Neurovascular Unit, Blood-Brain Barrier, and Tight Junctions

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of coronavirus disease 2019 (COVID-19), could affect brain structure and function. SARS-CoV-2 can enter the brain through different routes, including the olfactory, trigeminal, and vagus nerves, and through blood and immunocytes. SARS-CoV-2 may also enter the brain from the peripheral blood through a disrupted blood-brain barrier (BBB). The neurovascular unit in the brain, composed of neurons, astrocytes, endothelial cells, and pericytes, protects brain parenchyma by regulating the entry of substances from the blood. The endothelial cells, pericytes, and astrocytes highly express angiotensin converting enzyme 2 (ACE2), indicating that the BBB can be disturbed by SARS-CoV-2 and lead to derangements of tight junction and adherens junction proteins. This leads to increased BBB permeability, leakage of blood components, and movement of immune cells into the brain parenchyma. SARS-CoV-2 may also cross microvascular endothelial cells through an ACE2 receptor-associated pathway. The exact mechanism of BBB dysregulation in COVID-19/neuro-COVID is not clearly known, nor is the development of long COVID. Various blood biomarkers could indicate disease severity and neurologic complications in COVID-19 and help objectively diagnose those developing long COVID. This review highlights the importance of neurovascular and BBB disruption, as well as some potentially useful biomarkers in COVID-19, and long COVID/neuro-COVID.

Ameliorative effects of 6‑gingerol in cerebral ischemia are mediated via the activation of antioxidant and anti‑inflammatory pathways

Focal ischemia occurs when an embolus or thrombus occludes an artery, causing the rapid obstruction of cerebral blood flow. Although stroke represents a main cause of disability and mortality in developing countries, therapeutic approaches available for this condition remain very limited. The aim of the present study was to examine the effects of the phytochemical, 6-gingerol, on the brain infarct volume, neuronal loss and on the oxidative stress parameters, cyclooxygenase-2 (COX-2) and interleukin (IL)-6, in an animal model of focal ischemic stroke. Male Wistar rats, weighing 250-300 g, were divided into the following six groups: i) The control; ii) right middle cerebral artery occlusion (Rt.MCAO) + vehicle; iii) Rt.MCAO + piracetam; iv) Rt.MCAO + 6-gingerol (6-Gin) at 5 mg/kg body weight (BW); v) Rt.MCAO + 6-Gin at 10 mg/kg BW; and vi) the Rt.MCAO + 6-Gin at 20 mg/kg BW group. The rats in each group received the vehicle or piracetam or 6-gingerol intraperitoneally for 7 days following Rt.MCAO. The brain infarct volume, neuronal loss and alterations in antioxidant and anti-inflammatory levels were assessed in the cortex and hippocampus. The results revealed that the brain infarct volume, malondialdehyde level and the density ratio of COX-2 and IL-6 to β-actin were significantly decreased following treatment with 6-gingerol. In addition, neuronal density and superoxide dismutase activity in the cortex and hippocampus were increased. On the whole, the findings of the present study suggest that 6-gingerol exerts antioxidant and anti-inflammatory effects in vivo, which effectively ameliorate the brain damage induced by focal cerebral ischemic strok.

Eriodictyol: a review of its pharmacological activities and molecular mechanisms related to ischemic stroke

Ischemic stroke (IS) is characterized by a prominent mortality and disability rate, which has increased the burden on the global economy to a certain extent. Meanwhile, patients benefit little from the limited clinical strategies of intravenous alteplase and thrombectomy due to the limited therapeutic window. Given this, it is urgent to study new therapeutic methods to intervene in these patients. Eriodyctiol (ERD) is a major natural flavonoid, which widely exists in fruits, vegetables, and medicinal herbs, and has various pharmacological properties. It has been reported that ERD can maintain homeostasis in organisms by exerting neuroprotective and vascular protective effects. Therefore, more and more studies have focused on the pharmacological activity and mechanism of ERD in IS. This paper provides an overview of the plant sources, phytochemical properties, pharmacokinetics, and pathogenesis, as well as the pharmacological effects and mechanisms of ERD in IS. To date, preclinical studies on ERD in diverse cell lines and animal models have established the idea of ERD as a feasible agent capable of specifically ameliorating IS. The molecular mechanisms of ERD to prevent or reduce IS are mainly based on the inhibition of inflammation, oxidative stress, autophagy and apoptosis. Nevertheless, the mechanism of ERD against IS is flawed and needs more exploration by the research community. Moreover, well-designed clinical trials are needed to increase the scientific validity of the beneficial effects of ERD against IS.

Overexpression of microRNA-381-3p ameliorates hypoxia/ischemia-induced neuronal damage and microglial inflammation via regulating the C-C chemokine receptor type 2 /nuclear transcription factor-kappa B axis

microRNAs, as small endogenous RNAs, influence umpteen sophisticated cellular biological functions regarding neurodegenerative and cerebrovascular diseases. Here, we interrogated miR-381-3p’s influence on BV2 activation and neurotoxicity in ischemic and hypoxic environment. Oxygen-glucose deprivation (OGD) was adopted to induce microglial activation and HT-22 neuron damage. Quantitative polymerase chain reaction (qRT-PCR) was taken to check miR-381-3p expression in OGD-elicited BV2 cells and HT-22 neurons. It transpired that miR-381-3p expression was lowered in BV2 cells and HT-22 cells elicited by OGD. miR-381-3p up-regulation remarkably hampered inflammatory mediator expression in BV2 cells induced by OGD and weakened HT22 neuron apoptosis. In vivo, miR-381-3p expression was abated in HI rats’ ischemic lesions, and miR-381-3p up-regulation could ameliorate inflammation and neuron apoptosis in their brain. C-C chemokine receptor type 2 (CCR2) was identified as the downstream target of miR-381-3p, and miR-381-3p suppressed the CCR2/NF-κB pathway to mitigate microglial activation and neurotoxicity. Therefore, we believed that miR-381-3p overexpression exerts anti-inflammation and anti-apoptosis in ischemic brain injury by targeting CCR2