Postischemic administration of liposome-encapsulated luteolin prevents against ischemia-reperfusion injury in a rat middle cerebral artery occlusion model

Luteolin: A promising multifunctional natural flavonoid for human diseases

Natural products are closely associated with human health. Luteolin (LUT), a flavonoid polyphenolic compound, is widely found in fruits, vegetables, flowers, and herbs. It is noteworthy that LUT exhibits a variety of beneficial pharmacological properties and holds significant potential for clinical applications, particularly in antitumor, anti-convulsion, diabetes control, anti-inflammatory, neuroprotection, anti-oxidation, anti-cardiovascular, and other aspects. The potential mechanism of action has been partially elucidated, including the mediation of NF-κB, toll-like receptor, MAPK, Wnt/β-catenin, PI3K/Akt, AMPK/mTOR, and Nrf-2, among others. The review that aimed to comprehensively consolidate essential information on natural sources, pharmacological effects, therapeutic and preventive potential, as well as potential mechanisms of LUT. The objective is to establish a theoretical basis for the continued development and application of LUT.

Nano-scale drug delivery systems for luteolin: advancements and applications

Luteolin (Lu) is a naturally occurring flavonoid compound with a diverse array of pharmacological activities, including anti-tumor, anti-inflammatory, antibacterial, and neuroprotective properties. However, the therapeutic efficacy and clinical application of Lu are significantly hindered by inherent limitations, such as poor water solubility, short half-life, low bioavailability, and potential off-target toxicity. Recent studies have demonstrated that the utilization of nanocarriers presents a promising strategy to enhance the solubility of Lu, prolong its circulation time, and improve its targeting ability. Despite numerous reviews over the past few decades having focused on the source, pharmacological activities, and molecular mechanisms of Lu, there exists a conspicuous gap in the literature regarding a comprehensive review of Lu-loaded nanoformulations and their applications. To address this gap, we present an exhaustive overview of the advancements and applications of nano-scale drug delivery systems specifically designed for Lu. These platforms encompass micelles, nanocarrier-based systems, emulsified drug delivery systems, and vesicular drug delivery systems. We provide detailed insights into the synthetic materials, preparation methods, physicochemical properties, and significant outcomes associated with these nanoformulations. This systematic review will be particularly valuable to researchers seeking novel avenues in the field of nano-delivery strategies and exploring the potential clinical applications of Lu.

Determination of Luteolin 7-Glucuronide in Perilla frutescens (L.) Britt. Leaf Extracts from Different Regions of China and Republic of Korea and Its Cholesterol-Lowering Effect

Lowering blood cholesterol levels is crucial for reducing the risk of cardiovascular disease in patients with familial hypercholesterolemia. To develop Perilla frutescens (L.) Britt. leaves as a functional food with a cholesterol-lowering effect, in this study, we collected P. frutescens (L.) Britt. leaves from different regions of China and Republic of Korea. On the basis of the extraction yield (all components; g/kg), we selected P. frutescens (L.) Britt. leaves from Hebei Province, China with an extract yield of 60.9 g/kg. After evaluating different concentrations of ethanol/water solvent for P. frutescens (L.) Britt. leaves, with luteolin 7-glucuronide as the indicator component, we selected a 30% ethanol/water solvent with a high luteolin 7-glucuronide content of 0.548 mg/g in Perilla. frutescens (L.) Britt. leaves. Subsequently, we evaluated the cholesterol-lowering effects of P. frutescens (L.) Britt. leaf extract and luteolin 7-glucuronide by detecting total cholesterol in HepG2 cells. The 30% ethanol extract lowered cholesterol levels significantly by downregulating 3-hydroxy-3-methyl-glutaryl-coenzyme A reductase expression. This suggests that P. frutescens (L.) Britt leaves have significant health benefits and can be explored as a potentially promising food additive for the prevention of hypercholesterolemia-related diseases.

Applications of Perilla frutescens Extracts in Clinical Practice

(1) Background: Perilla frutescens (L.) Britt. is an important pharmaceutical crop that remains a focus point for researchers worldwide due to its complex phytochemical constituents, medicinal effects, and nutraceutical properties. The literature data are based on animal and cell culture studies, so the clinical evidence for the therapeutic effects is poorly outlined. The aim of this review was to provide an updated and thorough understanding of Perilla frutescens applications in clinical practice using data derived from human studies, and to outline the potential directions and perspectives for further studies on this crop. (2) Methods: Medline, Embase, and Cochrane databases were used to find relevant studies. All interventional studies that evaluated the effect of Perilla frutescens in human subjects were assessed. (3) Results: The main perspectives that can be contoured from the presented literature evaluation are an important clinical effect of Perilla frutescens extracts on allergic rhinoconjuctivitis, especially in young populations, a potent hypolipemiant effect that, in conjunction with increased serum biological antioxidant potential, determines significant improvements in cognitive function and a wide variety of miscellaneous clinical effects that need further exploration. (4) Conclusions: Supplementary research is needed in order to demonstrate the therapeutic effects of Perilla frutescens in controlled clinical settings.

Brain Energy Metabolism in Ischemic Stroke: Effects of Smoking and Diabetes

Proper regulation of energy metabolism in the brain is crucial for maintaining brain activity in physiological and different pathophysiological conditions. Ischemic stroke has a complex pathophysiology which includes perturbations in the brain energy metabolism processes which can contribute to worsening of brain injury and stroke outcome. Smoking and diabetes are common risk factors and comorbid conditions for ischemic stroke which have also been associated with disruptions in brain energy metabolism. Simultaneous presence of these conditions may further alter energy metabolism in the brain leading to a poor clinical prognosis after an ischemic stroke event. In this review, we discuss the possible effects of smoking and/or diabetes on brain glucose utilization and mitochondrial energy metabolism which, when present concurrently, may exacerbate energy metabolism in the ischemic brain. More research is needed to investigate brain glucose utilization and mitochondrial oxidative metabolism in ischemic stroke in the presence of smoking and/or diabetes, which would provide further insights on the pathophysiology of these comorbid conditions and facilitate the development of therapeutic interventions.

The Effect of Prosopis farcta and Its Bioactive Luteolin on the Hippocampus of Mice after Induced Ischemia Reperfusion

Background

Ischemia plays an important role in increasing damage to the nervous system. This study aimed to evaluate the effect of Prosopis farcta (PFE) and its bioactive luteolin (Lu) and forced swimming exercise on the hippocampus of mice after induced ischemia reperfusion.

Methods

The bioactive component of PFE (Lu) was identified by HPLC. Fifty-six male mice were divided into different groups. Ischemia was induced by ligation of the common carotid artery. After mice training (swimming exercise, 8 weeks) and consuming PFE and Lu, the mice's memory ability was evaluated in the shuttle box. Histological examination was performed by Nissel staining and immunohistochemistry.

Results

Results showed that the ischemic mice exercised and treated with PFE and Lu had higher step-through latency (STL) compared with the nonexercised mice, and this was confirmed with time spent in the dark compartment (TDC). The number of dark cells in the ischemic group exercising and receiving PFE and Lu decreased compared to that of the other groups in the hippocampus. DCX protein expression was increased in nonexercised groups compared to that of the exercised groups and those treated with PFE and Lu, while NeuN decreased.

Conclusions

Forced swimming exercise following ischemia, as well as consumption of PFE and Lu, has reduced cell death and increased neurogenesis in the hippocampus and thus may help improve memory in ischemia.

Exploration of the mechanism of luteolin against ischemic stroke based on network pharmacology, molecular docking and experimental verification

Stroke is a leading cause of morbidity and mortality worldwide. As the most common type of stroke cases, treatment effectiveness is still limited despite intensive research. Recently, traditional Chinese medicine has attracted attention because of potential benefits for stroke treatment. Among these, luteolin, a natural plant flavonoid compound, offers neuroprotection following against ischemic stroke, although the specific mechanisms are unknown. Here we used network pharmacology, molecular docking, and experimental verification to explore the mechanisms whereby luteolin can benefit stroke recovery. The pharmacological and molecular properties of luteolin were obtained from Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform. The potential targets of luteolin and ischemic stroke were collected from interrogating public databases. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway analyses were performed by Funrich and Database for Annotation, Visualization and Integrated Discovery respectively, a luteolin-target-pathway network constructed using Cytoscape, Autodock vina was used for molecular docking simulation with Discovery Studio was used to visualize and analyze the docked conformations. Lastly, we employed an in vitro model of stroke injury to evaluate the effects of luteolin on cell survival and expression of the putative targets. From 95 candidate luteolin target genes, our analysis identified six core targets . KEGG analysis of the candidate targets identified that luteolin provides therapeutic effects on stroke through TNF signaling and other pathways. Our experimental analyses confirmed the conclusions analyzed above. In summary, the molecular and pharmacological mechanisms of luteolin against stroke are indicated in our study from a systematic perspective.

TCMIP v2.0 Powers the Identification of Chemical Constituents Available in Xinglou Chengqi Decoction and the Exploration of Pharmacological Mechanisms Acting on Stroke Complicated With Tanre Fushi Syndrome

Xinglou Chengqi (XLCQ) decoction, composed of three botanical drugs and one inorganic drug, is used in clinics during the treatment of acute stroke complicated with Tanre Fushi (TRFS) syndrome in China. However, its active ingredients and the molecular mechanism have not been clarified. So, we aimed to preliminarily characterize its chemical constituents and investigate its pharmacological mechanisms using an integrative pharmacology strategy, including component analysis, network prediction, and experimental verification. We employed UPLC-QTOF-MS/MS to describe the chemical profile of XLCQ, Integrative Pharmacology-based Network Computational Research Platform of Traditional Chinese Medicine (TCMIP v2.0, http://www.tcmip.cn/), to assist in identifying the chemical components and predict the putative molecular mechanism against acute stroke complicated with TRFS, and LPS-stimulated BV-2 cells to verify the anti-neuroinflammatory effects of luteolin, apigenin, and chrysoeriol. Altogether, 197 chemical compounds were identified or tentatively characterized in the water extraction of XLCQ, 22 of them were selected as the key active constituents that may improve the pathological state by regulating 27 corresponding targets that are mainly involved in inflammation/immune-related pathways, and furthermore, luteolin, apigenin, and chrysoeriol exhibited good anti-neuroinflammatory effects from both protein and mRNA levels. In summary, it is the first time to employ an integrative pharmacology strategy to delineate 22 constituents that may improve the pathological state of stroke with TRFS by regulating 27 corresponding targets, which may offer a highly efficient way to mine the scientific connotation of traditional Chinese medicine prescriptions. This study might be a supplement for the deficiency of the basic research of XLCQ.

Neuroprotective Phytochemicals in Experimental Ischemic Stroke: Mechanisms and Potential Clinical Applications

Ischemic stroke is a challenging disease with high mortality and disability rates, causing a great economic and social burden worldwide. During ischemic stroke, ionic imbalance and excitotoxicity, oxidative stress, and inflammation are developed in a relatively certain order, which then activate the cell death pathways directly or indirectly via the promotion of organelle dysfunction. Neuroprotection, a therapy that is aimed at inhibiting this damaging cascade, is therefore an important therapeutic strategy for ischemic stroke. Notably, phytochemicals showed great neuroprotective potential in preclinical research via various strategies including modulation of calcium levels and antiexcitotoxicity, antioxidation, anti-inflammation and BBB protection, mitochondrial protection and antiapoptosis, autophagy/mitophagy regulation, and regulation of neurotrophin release. In this review, we summarize the research works that report the neuroprotective activity of phytochemicals in the past 10 years and discuss the neuroprotective mechanisms and potential clinical applications of 148 phytochemicals that belong to the categories of flavonoids, stilbenoids, other phenols, terpenoids, and alkaloids. Among them, scutellarin, pinocembrin, puerarin, hydroxysafflor yellow A, salvianolic acids, rosmarinic acid, borneol, bilobalide, ginkgolides, ginsenoside Rd, and vinpocetine show great potential in clinical ischemic stroke treatment. This review will serve as a powerful reference for the screening of phytochemicals with potential clinical applications in ischemic stroke or the synthesis of new neuroprotective agents that take phytochemicals as leading compounds.

Protection against Alzheimer's disease by luteolin: Role of brain glucose regulation, anti-inflammatory activity, and the gut microbiota-liver-brain axis

Luteolin is a widely distributed flavone herbs and vegetables. It has anti-oxidant and anti-inflammatory activities and improves glucose metabolism by potentiating insulin sensitivity and improving β-cell function and mass. Alzheimer's disease (AD) is induced by the deposition of amyloid-beta (Aβ) in the hippocampus and the formation of neurotoxic Aβ plaques. The Aβ deposition is associated with increased formation of Aβ from amyloid precursor protein by up-regulation of β-secretase and β-site amyloid precursor protein-cleaving enzyme 1 (BACE1). Furthermore, Aβ accumulation is increased by brain insulin resistance. The impairment of insulin/IGF-1 signaling mainly in the hippocampus and brain insulin resistance is connected to signals originating in the liver and gut microbiota, known as the gut microbiota-liver-brain axis. This indicates that the changes in the production of short-chain fatty acids by the gut microbiota and pro-inflammatory cytokines can alter insulin resistance in the liver and brain. Luteolin is detected in the brain tissues after passing through the blood-brain barrier, where it can directly influence neuroinflammation and brain insulin resistance and modulate Aβ deposition. Luteolin (10-70 mg/kg bw for rodents) can modulate the systemic and brain insulin resistance, and it suppresses AD development directly, and it influences Aβ deposition by activation of the gut microbiota-liver-brain axis. In this review, we evaluate the potential of luteolin to mitigate two potential causes of AD, neuroinflammatory processes, and disruption of glucose metabolism in the brain. This review suggests that luteolin intake can enhance brain insulin resistance and neuroinflammation, directly and indirectly, to protect against the development of Alzheimer's-like disease, and the gut microbiota-liver-brain axis is mainly involved in the indirect pathway. However, most studies have been conducted in animal studies, and human clinical trials are needed.

Co-ultraPEALut: Role in Preclinical and Clinical Delirium Manifestations

BACKGROUND

Delirium is a disorder in awareness, attention and cognition. Pathophysiologically it is a response to stress. Postoperative delirium (POD) is a usual complication in aged patients following hip fracture surgery. Neuroinflammation is an important factor linked with the progress of POD. Though there are no efficient cures for delirium the endocannabinoid system may have a role in neuropsychiatric disorders.

OBJECTIVE

Therefore, we examined the effects of co-ultramicronized PEALut (co-ultraPEALut) in the LPS murine model of delirium and in elderly hip fractured patients.

METHODS

In the preclinical study, mice were injected intraperitoneally (i.p.) with Escherichia coli LPS (10 mg/kg). Co-ultraPEALut (1 mg/kg o.s.) was administered 1h before LPS injection or 1h and 6h after LPS injection or 1h before LPS injection and 1h and 6h after LPS. In the clinical study, the effects of Glialia® (co-ultramicronized 700 mg PEA + 70 mg luteolin) administration was evaluated in elderly hip fractured patients with an interventional, randomized, single-blind, monocentric study.

RESULTS

Administration of co-ultraPEALut to LPS-challenged mice ameliorated cognitive dysfunctions and locomotor activity; moreover, it reduced inflammation and apoptosis, while stimulating antioxidant response and limiting the loss of neurotrophins. In the clinical study, the results obtained demonstrated that administration of Glialia® to these surgical patients prevented the onset of POD and attenuated symptom intensity and their duration.

CONCLUSION

Therefore, the results obtained enhanced the idea that co-ultraPEALut may be a potential treatment to control cognitive impairment and the inflammatory and oxidative processes associated with delirium.

Alzheimer's disease: natural products as inhibitors of neuroinflammation

Alzheimer’s disease (AD) is the most common form of dementia and affects 44 million people worldwide. New emerging evidence from pre-clinical and clinical investigations shows that neuroinflammation is a major pathological component of AD suggesting that anti-inflammatory strategies are important in delaying the onset or slowing the progression of the disease. However, efforts to employ current anti-inflammatory agents in AD clinical trials have produced limited success. Consequently, there is a need to explore anti-inflammatory natural products, which target neuroinflammatory pathways relevant to AD pathogenesis. This review summarises important druggable molecular targets of neuroinflammation and presents classes of anti-neuroinflammatory natural products with potentials for preventing and reducing symptoms of AD.

Nose to brain drug delivery - A promising strategy for active components from herbal medicine for treating cerebral ischemia reperfusion

Cerebral ischemia reperfusion injury (CIRI), one of the major causes of death from stroke in the world, not only causes tremendous damage to human health, but also brings heavy economic burden to society. Current available treatments for CIRI, including mechanical therapies and drug therapies, are often accompanied by significant side-effects. Therefore, it is necessary to discovery new strategies for treating CIRI. Many studies have confirmed that the herbal medicine has the advantages of abundant resources, good curative effect and little side effects, which can be used as potential drug for treatment of CIRI through multiple targets. It's known that oral administration commonly has low bioavailability, and injection administration is inconvenient and unsafe. Many drugs can't delivery to brain through routine pathways due to the blood-brain-barrier (BBB). Interestingly, increasing evidences have suggested the nasal administration is a potential direct route to transport drug into brain avoiding the BBB and has the characteristics of high bioavailability for treating brain diseases. Therefore, intranasal administration can be treated as an alternative way to treat brain diseases. In the present review, effective methods to treat CIRI by using active ingredients derived from herbal medicine through nose to brain drug delivery (NBDD) are updated and discussed, and some related pharmacological mechanisms have also been emphasized. Our present study would be beneficial for the further drug development of natural agents from herbal medicines via NBDD.

Novel approaches for the delivery of therapeutics in ischemic stroke

Here, we review novel approaches to deliver neuroprotective drugs to salvageable penumbral brain areas of stroke injury with the goals of offsetting ischemic brain injury and enhancing recovery.

Nanocarriers for Stroke Therapy: Advances and Obstacles in Translating Animal Studies

The technology of drug delivery systems (DDS) has expanded into many applications, such as for treating neurological disorders. Nanoparticle DDS offer a unique strategy for targeted transport and improved outcomes of therapeutics. Stroke is likely to benefit from the emergence of this technology though clinical breakthroughs are yet to manifest. This review explores the recent advances in this field and provides insight on the trends, prospects and challenges of translating this technology to clinical application. Carriers of diverse material compositions are presented, with special focus on the surface properties and emphasis on the similarities and inconsistencies among in vivo experimental paradigms. Research attention is scattered among various nanoparticle DDS and various routes of drug administration, which expresses the lack of consistency among studies. Analysis of current literature reveals lipid- and polymer-based DDS as forerunners of DDS for stroke; however, cell membrane-derived vesicles (CMVs) possess the competitive edge due to their innate biocompatibility and superior efficacy. Conversely, inorganic and carbon-based DDS offer different functionalities as well as varied capacity for loading but suffer mainly from poor safety and general lack of investigation in this area. This review supports the existing literature by systematizing presently available data and accounting for the differences in drugs of choice, carrier types, animal models, intervention strategies and outcome parameters.

The Role of Mast Cells in Stroke

Mast cells (MCs) are densely granulated perivascular resident cells of hematopoietic origin. Through the release of preformed mediators stored in their granules and newly synthesized molecules, they are able to initiate, modulate, and prolong the immune response upon activation. Their presence in the central nervous system (CNS) has been documented for more than a century. Over the years, MCs have been associated with various neuroinflammatory conditions of CNS, including stroke. They can exacerbate CNS damage in models of ischemic and hemorrhagic stroke by amplifying the inflammatory responses and promoting brain–blood barrier disruption, brain edema, extravasation, and hemorrhage. Here, we review the role of these peculiar cells in the pathophysiology of stroke, in both immature and adult brain. Further, we discuss the role of MCs as potential targets for the treatment of stroke and the compounds potentially active as MCs modulators.

Connectivity map identifies luteolin as a treatment option of ischemic stroke by inhibiting MMP9 and activation of the PI3K/Akt signaling pathway

This study aimed to explore potential new drugs in the treatment of ischemic stroke by Connectivity Map (CMap) and to determine the role of luteolin on ischemic stroke according to its effects on matrix metalloproteinase-9 (MMP9) and PI3K/Akt signaling pathway. Based on published gene expression data, differentially expressed genes were obtained by microarray analysis. Potential compounds for ischemic stroke therapy were obtained by CMap analysis. Cytoscape and gene set enrichment analysis (GSEA) were used to discover signaling pathways connected to ischemic stroke. Cell apoptosis and viability were, respectively, evaluated by flow cytometry and an MTT (3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide) assay. Quantitative real-time polymerase chain reaction (qRT-PCR) and western blot analysis were used to test the expression of MMP9 and the PI3K/Akt signaling pathway-related proteins in human brain microvascular endothelial cells (HBMECs) and tissues. Additionally, the infarct volume after middle cerebral artery occlusion (MCAO) was determined by a TTC (2,3,5-triphenyltetrazolium chloride) assay. The microarray and CMap analyses identified luteolin as a promising compound for future therapies for ischemic stroke. Cytoscape and GSEA showed that the PI3K/Akt signaling pathway was crucial in ischemic stroke. Cell experiments revealed that luteolin enhanced cell viability and downregulated apoptosis via inhibiting MMP9 and activating the PI3K/Akt signaling pathway. Experiments performed in vivo also demonstrated that luteolin reduced the infarct volume. These results suggest that luteolin has potential in the treatment of ischemic stroke through inhibiting MMP9 and activating PI3K/Akt signaling pathway.

Ethnomedicinal, Phytochemical and Pharmacological Investigations of Perilla frutescens (L.) Britt

Perilla frutescens (L.) Britt. (PF) is an annual herbal medicinal, aromatic, functional food, and ornamental plant that belongs to the mint family, Lamiaceae. The origin of perilla traces back to East Asian countries (China, Japan, Korea, Taiwan, Vietnam, and India), where it has been used as a valuable source of culinary and traditional medicinal uses. The leaves, seeds, and stems of P. frutescens are used for various therapeutic applications in folk medicine. In the absence of a comprehensive review regarding all aspects of perilla, this review aims to present an overview pertaining to the botanical drug, ethnobotany, phytochemistry, and biological activity. It was found that the taxonomic classification of perilla species is quite confused, and the number of species is vague. Perilla has traditionally been prescribed to treat depression-related disease, anxiety, asthma, chest stuffiness, vomiting, coughs, colds, flus, phlegm, tumors, allergies, intoxication, fever, headache, stuffy nose, constipation, abdominal pain, and indigestion, and acts as an analgesic, anti-abortive agent, and a sedative. Until now, 271 natural molecules have been identified in perilla organs including phenolic acids, flavonoids, essential oils, triterpenes, carotenoids, phytosterols, fatty acids, tocopherols, and policosanols. In addition to solvent extracts, these individual compounds (rosmarinic acid, perillaldehyde, luteolin, apigenin, tormentic acid, and isoegomaketone) have attracted researchers' interest for its pharmacological properties. Perilla showed various biological activities such as antioxidant, antimicrobial, anti-allergic, antidepressant, anti-inflammatory, anticancer, and neuroprotection effects. Although the results are promising in preclinical studies (in vitro and in vivo), clinical studies are insufficient; therefore, further study needs to be done to validate its therapeutic effects and to ensure its safety and efficacy.

Bio-effectiveness of the main flavonoids of Achillea millefolium in the pathophysiology of neurodegenerative disorders- a review

The Achillea millefolium L. (Yarrow) is a common herb which is widely being used, worldwide. Achillea is being used for treatment of many disorders since centuries. It is considered safe for supplemental use and flavonoids such as kaempferol, luteolin and apigenin are of main constituents present in Achillea. Most of both antioxidant and anti-inflammatory properties of this herb have been attributed to its flavonoid content. Oxidative and inflammatory processes play important roles in pathogenesis of neurodegenerative diseases. Present review was aimed to review the latest literature evidences regarding application of Achillea and/or its three main flavonoid constituents on epilepsy, Alzheimer's disease, multiple sclerosis, Parkinson's disease and stroke.

Comparative effects of plant oils and trans-fat on blood lipid profiles and ischemic stroke in rats

Since plant oils are believed to be better than animal fats for cerebrovascular and cardiovascular diseases, the effects of various plant oils and trans-fat on blood lipid profiles and ischemic stroke were investigated. Sprague-Dawley rats were fed a diet containing the oils or trans-fat, and then body weights, blood lipids, and effects on brain infarction and physical dysfunction induced by middle cerebral artery occlusion (MCAO) were analyzed. All the oils and trans-fat, except perilla oil, significantly increased body fats and body weight gain. Sesame oil and trans-fat specifically increased blood cholesterols and triglycerides, respectively, while perilla oil decreased both cholesterols and triglycerides. Perilla oil not only attenuated cerebral infarction, but also restored locomotor activity and rota-rod performances of MCAO rats. It is suggested that perilla oil among oils and fats could be the first choice to reduce the risk of metabolic syndrome and ischemic stroke.

Phytochemical and phytopharmacological review of Perilla frutescens L. (Labiatae), a traditional edible-medicinal herb in China

Perilla frutescens (L.) Britt., a worldwide distributed plant, is an important economic crop and with a long cultivation history in China as well as some other countries in Asia. Except for the edible applications, the plant of P. frutescens is also traditionally used as a medicinal herb in China for thousands years. The leaves, seeds and stems of P. frutescens are recommended by the Chinese Pharmacopeia as three medicinal materials for various therapeutic applications. In the past decades, amount investigations have been done about different aspects for P. frutescens. However, no literature review about these works has been compiled. This review aims to present the findings of research conducted up-to-date (2015) on the traditional use, phytochemicals, pharmacological activities and toxicities of P. frutescens to provide scientific evidence for well-understanding and future research of P. frutescens. It was found that more than 100 compounds have been reported for P. frutescens and most of them are contributed to its medical benefits such as anti-allergic, anti-inflammatory, anti-oxidant, anticancer, anti-microbial, anti-depressive and anti-cough effects. Toxicology studies have been conducted to evaluate the safety of P. frutescens to provide information on their dosages and usages.

Getting into the brain: liposome-based strategies for effective drug delivery across the blood-brain barrier

This review summarizes articles that have been reported in literature on liposome-based strategies for effective drug delivery across the blood–brain barrier. Due to their unique physicochemical characteristics, liposomes have been widely investigated for their application in drug delivery and in vivo bioimaging for the treatment and/or diagnosis of neurological diseases, such as Alzheimer’s, Parkinson’s, stroke, and glioma. Several strategies have been used to deliver drug and/or imaging agents to the brain. Covalent ligation of such macromolecules as peptides, antibodies, and RNA aptamers is an effective method for receptor-targeting liposomes, which allows their blood–brain barrier penetration and/or the delivery of their therapeutic molecule specifically to the disease site. Additionally, methods have been employed for the development of liposomes that can respond to external stimuli. It can be concluded that the development of liposomes for brain delivery is still in its infancy, although these systems have the potential to revolutionize the ways in which medicine is administered.

Anti-atherosclerotic effects of perilla oil in rabbits fed a high-cholesterol diet

Anti-atherosclerosis effects of perilla oil were investigated, in comparison with lovastatin, in rabbits fed a high-cholesterol diet (HCD). Hypercholesterolemia was induced in rabbits by feeding the HCD containing 0.5% cholesterol and 1% corn oil, and perilla oil (0.1 or 0.3%) was added to the diet containing 0.5% cholesterol for 10 weeks. HCD greatly increased blood total cholesterol and low-density lipoproteins, and caused thick atheromatous plaques, covering 74% of the aortic wall. Hyper-cholesterolemia also induced lipid accumulation in the liver and kidneys, leading to lipid peroxidation. Perilla oil not only attenuated hypercholesterolemia and atheroma formation, but also reduced fat accumulation and lipid peroxidation in hepatic and renal tissues. The results indicate that perilla oil prevents atherosclerosis and fatty liver by controlling lipid metabolism, and that it could be the first choice oil to improve diet-induced metabolic syndrome.

PEA and luteolin synergistically reduce mast cell-mediated toxicity and elicit neuroprotection in cell-based models of brain ischemia

The combination of palmitoylethanolamide (PEA), an endogenous fatty acid amide belonging to the family of the N-acylethanolamines, and the flavonoid luteolin has been found to exert neuroprotective activities in a variety of mouse models of neurological disorders, including brain ischemia. Indirect findings suggest that the two molecules can reduce the activation of mastocytes in brain ischemia, thus modulating crucial cells that trigger the inflammatory cascade. Though, no evidence exists about a direct effect of PEA and luteolin on mast cells in experimental models of brain ischemia, either used separately or in combination. In order to fill this gap, we developed a novel cell-based model of severe brain ischemia consisting of primary mouse cortical neurons and cloned mast cells derived from mouse fetal liver (MC/9 cells) subjected to oxygen and glucose deprivation (OGD). OGD exposure promoted both mast cell degranulation and the release of lactate dehydrogenase (LDH) in a time-dependent fashion. MC/9 cells exacerbated neuronal damage in neuron-mast cells co-cultures exposed to OGD. Likewise, the conditioned medium derived from OGD-exposed MC/9 cells induced significant neurotoxicity in control primary neurons. PEA and luteolin pre-treatment synergistically prevented the OGD-induced degranulation of mast cells and reduced the neurotoxic potential of MC/9 cells conditioned medium. Finally, the association of the two drugs promoted a direct synergistic neuroprotection even in pure cortical neurons exposed to OGD. In summary, our results indicate that mast cells release neurotoxic factors upon OGD-induced activation. The association PEA-luteolin actively reduces mast cell-mediated neurotoxicity as well as pure neurons susceptibility to OGD.

Mitochondrial function in hypoxic ischemic injury and influence of aging

Mitochondria are a major target in hypoxic/ischemic injury. Mitochondrial impairment increases with age leading to dysregulation of molecular pathways linked to mitochondria. The perturbation of mitochondrial homeostasis and cellular energetics worsens outcome following hypoxic-ischemic insults in elderly individuals. In response to acute injury conditions, cellular machinery relies on rapid adaptations by modulating posttranslational modifications. Therefore, post-translational regulation of molecular mediators such as hypoxia-inducible factor 1α (HIF-1α), peroxisome proliferator-activated receptor γ coactivator α (PGC-1α), c-MYC, SIRT1 and AMPK play a critical role in the control of the glycolytic-mitochondrial energy axis in response to hypoxic-ischemic conditions. The deficiency of oxygen and nutrients leads to decreased energetic reliance on mitochondria, promoting glycolysis. The combination of pseudohypoxia, declining autophagy, and dysregulation of stress responses with aging adds to impaired host response to hypoxic-ischemic injury. Furthermore, intermitochondrial signal propagation and tissue wide oscillations in mitochondrial metabolism in response to oxidative stress are emerging as vital to cellular energetics. Recently reported intercellular transport of mitochondria through tunneling nanotubes also play a role in the response to and treatments for ischemic injury. In this review we attempt to provide an overview of some of the molecular mechanisms and potential therapies involved in the alteration of cellular energetics with aging and injury with a neurobiological perspective.

Luteolin rescues pentylenetetrazole-induced cognitive impairment in epileptic rats by reducing oxidative stress and activating PKA/CREB/BDNF signaling

Most antiepileptic drugs (AEDs) interfere with cognitive function, and there is therefore an urgent need for AEDs that are effective but do not have this side effect. Various studies have reported the antiinflammatory and cytoprotective properties of the natural flavonoid luteolin (LU); however, none has examined systematically its antiseizure potential. The current study investigated the effects of LU on pentylenetetrazole (PTZ)-induced cognitive impairment in rats and the underlying mechanisms. Seizures were induced in rats by daily injection of PTZ for 36 days. Two other groups were pretreated with LU (50 or 100 mg/kg/day by oral administration) 30 min prior to PTZ administration. Seizure severity was scored, and cognitive function was tested in the Morris water maze. Neuronal damage, mitochondrial generation of reactive oxygen species, oxidative stress, phosphoactivation of the protein kinase A (PKA)-cyclic AMP response element-binding protein (CREB) pathway, and brain-derived neurotrophic factor (BDNF) expression were measured in the hippocampus. Pretreatment with LU suppressed seizure induction, duration, and severity following PTZ injection, reversed cognitive impairment, reduced neuronal and oxidative stress damage, and increased phosphoactivation of PKA and CREB as well as BDNF expression. These results indicate that LU should be further investigated as a treatment for epilepsy.

New perspectives on dietary-derived treatments and food safety-antinomy in a new era

Despite the advances in science and technology and wide use of chemical drugs, dietary intervention (or food therapy) remains useful in preventing or treating many human diseases. A huge body of evidence shows that the dietary pattern or habit is also an important contributing factor to the development of chronic diseases such as hypertension, type 2 diabetes, hyperlipidemia, and cancers. In recent years, over-the-counter health foods, nutraceuticals, and plant-derived medicinal products have been gaining popularity all over the world, particularly in developed countries. Unfortunately, owing to the contamination with various harmful substances in foods and the presence of toxic food components, food-borne diseases have also become increasingly problematic. Incidents of food poisonings or tainted food have been increasing worldwide, particularly in China and other developing countries. Therefore, the government should put in a greater effort in enforcing food safety by improving the surveillance mechanism and exerting highest standards of quality control for foods.

Adaptive cellular stress pathways as therapeutic targets of dietary phytochemicals: focus on the nervous system

During the past 5 decades, it has been widely promulgated that the chemicals in plants that are good for health act as direct scavengers of free radicals. Here we review evidence that favors a different hypothesis for the health benefits of plant consumption, namely, that some phytochemicals exert disease-preventive and therapeutic actions by engaging one or more adaptive cellular response pathways in cells. The evolutionary basis for the latter mechanism is grounded in the fact that plants produce natural antifeedant/noxious chemicals that discourage insects and other organisms from eating them. However, in the amounts typically consumed by humans, the phytochemicals activate one or more conserved adaptive cellular stress response pathways and thereby enhance the ability of cells to resist injury and disease. Examplesof such pathways include those involving the transcription factors nuclear factor erythroid 2-related factor 2, nuclear factor-κB, hypoxia-inducible factor 1α, peroxisome proliferator-activated receptor γ, and forkhead box subgroup O, as well as the production and action of trophic factors and hormones. Translational research to develop interventions that target these pathways may lead to new classes of therapeutic agents that act by stimulating adaptive stress response pathways to bolster endogenous defenses against tissue injury and disease. Because neurons are particularly sensitive to potentially noxious phytochemicals, we focus on the nervous system but also include findings from other cell types in which actions of phytochemicals on specific signal transduction pathways have been more thoroughly studied.

The effects of luteolin on the intestinal ischemia/reperfusion injury in mice

The purpose of this study is to investigate the potential protective effect of the flavonoid Luteolin on ischemia-reperfusion (IR) injury in mouse intestine, which has not previously been studied. Twenty-four female C57BL/6 mice were randomly assigned to four groups, each consisting of 6 mice: a sham group (laparotomy, but no IR injury), a sham + Luteolin group (no IR, and Luteolin was administered intraperitoneally 30 min after laparotomy), IR group (30 min occlusion of the superior mesenteric artery (SMA) then 2 hr' reperfusion), IR + Luteolin (30 min occlusion of the SMA then 2 hr' reperfusion; Luteolin was administered intraperitoneally before reperfusion). Intestine tissues were harvested from the mice for histopathological and biochemical analysis. Total oxidant status (TOS) and total antioxidant capacity (TAC) of the intestinal tissues were measured using Erel's method. Oxidative stress index (OSI) was calculated using the TOS/TAC ratio. Intestinal histological changes were significantly decreased in the IR + Luteolin group compared with the IR group (p = .037). TOS tissue levels were also significantly decreased in the IR + Luteolin group compared with the IR group (p = .005). TAC levels did not increase significantly in the IR treatment group and were not affected by Luteolin treatment (p > .05). The results of this study show that Luteolin administration provides considerable protection against IR injury in the mouse intestine.

Luteolin attenuates neuronal apoptosis in the hippocampi of diabetic encephalopathy rats

Luteolin (3’,4’,5,7-tetrahydroxyflavone) has powerful anti-apoptotic and antioxidant properties. This study aimed to investigate the effects of luteolin on hyperglycemia-mediated apoptosis in the hippocampi of rats with streptozotocin-induced diabetic encephalopathy after injection into the tail veins, and the molecular mechanisms involved. Biochemistry and terminal deoxynucleotidyl transferase mediated dUTP nick end labelling detection results showed that luteolin treatment (given twice daily for 15 days) significantly inhibited hyperglycemia-mediated apoptosis, decreased malondialdehyde levels and increased glutathione levels in the hippocampi of streptozotocin-induced diabetic rats. Western blot analysis revealed that luteolin also inhibited the expression of apoptosis-related factors and cytochrome c release from mitochondria. Luteolin also improved the learning and memory abilities of rats with diabetic encephalopathy in a water maze test. Further western blot analysis revealed that luteolin treatment facilitated neuronal cell survival through activation of the phosphatidylinositol 3-kinase/Akt signaling pathway, an extracellular signal pathway involved in the suppression of cell apoptosis and promotion of cell survival. These experimental findings indicate that luteolin can inhibit apoptosis of hippocampal nerve cells in rats with diabetic encephalopathy, and that this effect is mediated by an indirect antioxidative effect, the inhibition of activation of apoptosis-related factors and the activation of phosphatidylinositol 3-kinase/Akt signal pathway.

Luteolin provides neuroprotection in models of traumatic brain injury via the Nrf2-ARE pathway

Luteolin has recently been proven to exert neuroprotection in a variety of neurological diseases; however, its roles and the underlying mechanisms in traumatic brain injury are not fully understood. The present study was aimed to investigate the neuroprotective effects of luteolin in models of traumatic brain injury (TBI) and the possible role of the Nrf2-ARE pathway in the putative neuroprotection. A modified Marmarou׳s weight-drop model in mice and the scratch model in mice primary cultured neurons were used to induce TBI. We determined that luteolin significantly ameliorated secondary brain injury induced by TBI, including neurological deficits, brain water content, and neuronal apoptosis. Furthermore, the level of malondialdehyde (MDA) and the activity of glutathione peroxidase (GPx) were restored in the group with luteolin treatment. in vitro studies showed that luteolin administration lowered the intracellular reactive oxygen species (ROS) level and increased the neuron survival. Moreover, luteolin enhanced the translocation of Nrf2 to the nucleus both in vivo and in vitro, which was proved by the results of Western blot, immunohistochemistry, and electrophoretic mobility shift assay (EMSA). Subsequently upregulation of the expression of the downstream factors such as heme oxygenase 1 (HO1) and

NAD(P)H

quinone oxidoreductase 1 (NQO1) was also examined. However, luteolin treatment failed to provide neuroprotection after TBI in Nrf2(-/-) mice. Taken together, these in vivo and in vitro data demonstrated that luteolin provided neuroprotective effects in the models of TBI, possibly through the activation of the Nrf2-ARE pathway.

Comparative effects of plant oils on the cerebral hemorrhage in stroke-prone spontaneously hypertensive rats

OBJECTIVES

Since oils and fats can induce metabolic syndrome, leading to cardiovascular and cerebrovascular diseases, the present study was performed to find out whether the plant oils affect the cerebral hemorrhage in stroke-prone spontaneously hypertensive (SHR-SP) rats.

METHODS

From 47 days of age, male SHR-SP rats were given drinking water containing 1% NaCl to induce hypertension, and simultaneously fed semi-purified diets containing 10% perilla oil, canola oil, or shortening. The onset time of convulsion following cerebral hemorrhage was recorded, and the areas of hemorrhage and infarction were analyzed in the stroke brains.

RESULTS

In comparison with 58-day survival of SHR-SP rats during feeding NaCl alone, perilla oil extended the survival time to 68.5 days, whereas canola oil shortened it to 45.7 days. Feeding perilla oil greatly reduced the total volume of cerebral hemorrhage from 17.27% in the control group to 4.53%, while shortening increased the lesions to 21.23%. In a microscopic analysis, perilla oil also markedly decreased the hemorrhagic and infarction lesions to 1/10 of those in control rats, in contrast to an exacerbating effect of shortening. In blood analyses, perilla oil reduced blood total cholesterol and low-density lipoproteins which were increased in SHR-SP, but canola oil further increased them and markedly lowered platelet counts.

DISCUSSION

Perilla oil delayed and attenuated cerebral hemorrhage by improving hyperlipidemia in hypertensive stroke animals, in contrast to the aggravating potential of canola oil and shortening. It is suggested that perilla oil should be the first choice oil for improving metabolic syndrome in hypertensive persons at risk of hemorrhagic stroke.

Protective effects of luteolin on cognitive impairments induced by psychological stress in mice

In the present study, the protective effects of luteolin were investigated against psychological stress-induced cognitive impairment. To emulate the psychological stress, mice received restraint stress for six hours daily, between 9:00 and 15:00 hours, for 21 consecutive days. The results of step-through test, open-field test and Morris Water Maze test demonstrated that psychological stress treatment could result in cognitive impairments in mice. This cognition dysfunction was improved by treatment with low- and medium-dose luteolin. In addition, psychological stress induced an increased serum corticosterone concentration with a decreased serum norepinephrine and dopamine concentration. These alterations were attenuated by treatment with luteolin. Also, psychological stress significantly decreased the glutathione (GSH) concentrations and superoxide dismutase (SOD) activities in prefrontal cortex and hippocampus, while the malondialdehyde (MDA) concentrations were enhanced. However, these oxidative alterations in prefrontal cortex and hippocampus induced by psychological stress were significantly reversed by treatment of luteolin. Further, the current study indicated a decline of catalase (CAT) activities in the hippocampus of the ST group, which was significantly prevented by low, medium and high dose of luteolin. On the other hand, there was no significance in CAT activities of the prefrontal cortex among the six groups. Collectively, the present results suggest that luteolin treatment serves as a key role in improving the psychological stress-induced cognitive impairments.

Antioxidant and Nrf2 inducing activities of luteolin, a flavonoid constituent in Ixeris sonchifolia Hance, provide neuroprotective effects against ischemia-induced cellular injury

Ixeris sonchifolia Hance is an herb distributed in northeastern part of China and has been used by natives to invigorate circulation. In the present study, bioactivity-guided fractionation of I. sonchifolia Hance extract was performed with the aim to isolate and identify the compounds underlying the potential protective effects against ischemia brain injury. Among the four fractions isolated from the herb extract, the ethyl acetate fraction was found to scavenge DPPH radicals, induce ARE-dependent transcriptional activity and upregulate Nrf2 protein levels. The isolation work focused on this fraction revealed the presence of two categories of compounds: flavonoids and sesquiterpene lactones. Among the five isolated flavonoids, luteolin was evaluated to possess direct and indirect antioxidant activities by scavenging free radicals and inducing the upregulation of ARE-dependent phase II enzymes. Concomitant with the findings from the cell-based assays, in the middle cerebral artery occlusion-induced ischemia rat model, administration of luteolin at 4 mg/kg displayed neuroprotective effects by reducing infarct area and inhibiting neuronal cell death. In summary, the obtained results suggest that flavonoids in I. sonchifolia Hance, in particular luteolin, contribute at least partly to the neuroprotective effects against ischemia-induced cellular injury and can be potentially developed for treatment of ischemia-reperfusion induced diseases.

Method parameters' impact on mortality and variability in rat stroke experiments: a meta-analysis

Background

Even though more than 600 stroke treatments have been shown effective in preclinical studies, clinically proven treatment alternatives for cerebral infarction remain scarce. Amongst the reasons for the discrepancy may be methodological shortcomings, such as high mortality and outcome variability, in the preclinical studies. A common approach in animal stroke experiments is that A) focal cerebral ischemia is inflicted, B) some type of treatment is administered and C) the infarct sizes are assessed. However, within this paradigm, the researcher has to make numerous methodological decisions, including choosing rat strain and type of surgical procedure. Even though a few studies have attempted to address the questions experimentally, a lack of consensus regarding the optimal methodology remains.

Methods

We therefore meta-analyzed data from 502 control groups described in 346 articles to find out how rat strain, procedure for causing focal cerebral ischemia and the type of filament coating affected mortality and infarct size variability.

Results

The Wistar strain and intraluminal filament procedure using a silicone coated filament was found optimal in lowering infarct size variability. The direct and endothelin methods rendered lower mortality rate, whereas the embolus method increased it compared to the filament method.

Conclusions

The current article provides means for researchers to adjust their middle cerebral artery occlusion (MCAo) protocols to minimize infarct size variability and mortality.

Luteolin downregulates TLR4, TLR5, NF-κB and p-p38MAPK expression, upregulates the p-ERK expression, and protects rat brains against focal ischemia

BACKGROUND

Inflammatory damage is known to be involved in ischemic stroke. Luteolin has been proved to elicit a series of biologic effects through its anti-inflammatory property in multiple sclerosis and rheumatoid arthritis. Whether this protective effect applies to ischemic injury in brain is still unknown, we therefore investigate the potential neuroprotective role of luteolin in ischemic stroke and the underlying mechanisms.

METHODS

Male Sprague-Dawley rats were subjected to pMCAO and luteolin was administered intraperitoneally immediately after surgery, then once daily thereafter. Neurological deficit, infarct volume, and brain water content were measured at 24 h and 72 h after stroke. The expression of TLR4, TLR5, and NF-κB were measured by real-time PCR, immunohistochemical staining (IHC), and Western blot. P38MAPK and extracellular signal-regulated kinase (ERK) were detected by IHC, and Western blot.

RESULTS

Compared with pMCAO group, luteolin significantly alleviated neurological deficit, decreased infarct volume and suppressed edema after ischemic stroke, which were accompanied with decreased expression of TLR4, TLR5, NF-κB and p-p38MAPK. Meanwhile, luteolin activated the expression of p-ERK1/2 (P<0.05).

CONCLUSIONS

Luteolin protected the brain from the damage caused by pMCAO, and this effect may be through downregulation of TLR4, TLR5, NF-κB, p38MAPK and upregulation of ERK expression.

Dietary flavonoids are neuroprotective through Nrf2-coordinated induction of endogenous cytoprotective proteins

Epidemiological studies have demonstrated that the consumption of fruits and vegetables is associated with reduced risk for cardiovascular disease and stroke. Detailed investigations into the specific dietary components of these foods have revealed that many polyphenolic constituents exert anti-oxidant effects on key substrates involved in the pathogenesis and progression of ischemic injury. These data have perpetuated the belief that the protective effects of flavonoids result from direct anti-oxidant actions at the levels of the cerebral vasculature and brain parenchyma. While many in vitro studies using purified extracts support this contention, first-pass metabolism alters the bioavailability of flavonoids such that the achievable concentrations after oral consumption are not consistent with this mechanism. Importantly, oral consumption of flavonoids may promote neural protection by facilitating the expression of gene products responsible for detoxifying the ischemic microenvironment through both anti-oxidative and anti-inflammatory actions. In particular, the transcriptional factor nuclear factor erythroid 2-related factor 2 has emerged as a critical regulator of flavonoid-mediated protection through the induction of various cytoprotective genes. The pleiotropic effects associated with potent transcriptional regulation likely represent the primary mechanisms of neural protection, as the flavonoid concentrations reaching ischemic tissues in vivo are sufficient to alter intracellular signal transduction but likely preclude the one-to-one stoichiometry necessary to confer protection by direct anti-oxidation. These data reflect an exciting new direction in the study of complementary and alternative medicine that may lead to the development of novel therapies for ischemic/hemorrhagic stroke, traumatic brain injury, and other neurological disorders.