A Chinese medicine preparation induces neuroprotection by regulating paracrine signaling of brain microvascular endothelial cells

Traditional Chinese medicine in treating ischemic stroke by modulating mitochondria: A comprehensive overview of experimental studies

Ischemic stroke has been a prominent focus of scientific investigation owing to its high prevalence, complex pathogenesis, and difficulties in treatment. Mitochondria play an important role in cellular energy homeostasis and are involved in neuronal death following ischemic stroke. Hence, maintaining mitochondrial function is critical for neuronal survival and neurological improvement in ischemic stroke, and mitochondria are key therapeutic targets in cerebral stroke research. With the benefits of high efficacy, low cost, and high safety, traditional Chinese medicine (TCM) has great advantages in preventing and treating ischemic stroke. Accumulating studies have explored the effect of TCM in preventing and treating ischemic stroke from the perspective of regulating mitochondrial structure and function. In this review, we discuss the molecular mechanisms by which mitochondria are involved in ischemic stroke. Furthermore, we summarized the current advances in TCM in preventing and treating ischemic stroke by modulating mitochondria. We aimed to provide a new perspective and enlightenment for TCM in the prevention and treatment of ischemic stroke by modulating mitochondria.

Panax notoginseng Saponins Protect Brain Microvascular Endothelial Cells against Oxygen-Glucose Deprivation/Resupply-Induced Necroptosis via Suppression of RIP1-RIP3-MLKL Signaling Pathway

Recently, necroptosis has emerged as one of the important mechanisms of ischemia stroke. Necroptosis can be rapidly activated in endothelial cells to cause vascular damage and neuroinflammation. Panax notoginseng saponins (PNS), an ingredient extracted from the root of Panax notoginseng (Burk.) F.H. Chen, was commonly used for ischemic stroke, while its molecular mechanism and targets have not been fully clarified. Our study aimed to clarify the anti-necroptosis effect of PNS by regulating RIP1-RIP3-MLKL signaling pathway in brain microvascular endothelial cells (BMECs) subjected to transient oxygen-glucose deprivation (OGD/resupply [R]). In vitro, the necroptosis model of rat BMECs was established by testing the effect of OGD/R in the presence of the pan-caspase inhibitor z-VAD-FMK. After administration of PNS and Nec-1, cell viability, cell death modality, the expression of RIP1-RIP3-MLKL pathway and mitochondrial membrane potential (Δψm) level were investigated in BMECs upon OGD/R injury. The results showed that PNS significantly enhanced cell viability of BMECs determined by CCK-8 analysis, and protected BMECs from necroptosis by Flow cytometry and TEM. In addition, PNS inhibited the phosphorylation of RIP1, RIP3, MLKL and the downstream expression of PGAM5 and Drp1, while similar results were observed in Nec-1 intervention. We further investigated whether PNS prevented the Δψm depolarization. Our current findings showed that PNS effectively reduced the occurrence of necroptosis in BMECs exposed to OGD/R by inhibition of the RIP1-RIP3-MLK signaling pathway and mitigation of mitochondrial damage. This study provided a novel insight of PNS application in clinics.

Mitochondrial-Respiration-Improving Effects of Three Different Gardeniae Fructus Preparations and Their Components

The processing method for Chinese traditional herbal medicine is "Pao Zhi" in Chinese. This study examined the efficacy of the Pao Zhi on the preparations of Gardeniae Fructus (GF) on a mitochondrial respiratory function in rats. To determine the efficacy of Pao Zhi, we investigated the effects of GF heat processing on mitochondrial respiratory function. To test the GF components, the rats were randomly divided into a geniposide-alone group, crocin-alone group, and combination groups and treated with geniposide and crocin at different ratios. The results showed that a high dose, raw GF was more effective in improving the neurological function, mitochondrial respiratory function, and activities of Na⁺-K⁺-ATPase and Ca²⁺-Mg²⁺-ATPase than the preparations that underwent heating. Moreover, mitochondrial ROS production was the lowest in the raw GF-treated group. In addition, treatments with crocin and GC3 were more effective than geniposide in improving the functional deficit in MCAO rats. In conclusion, our results suggest that raw GF is the most suitable preparation for the treatment of cerebral ischemia, and its underlying mechanisms may be associated with the improvement of mitochondrial respiratory function, increased activities of Na⁺-K⁺-ATPase and Ca²⁺-Mg²⁺-ATPase, and reduced oxidative stress in mitochondria. Our findings suggest that raw GF, especially crocin, could be an ideal therapeutic agent for ischemic stroke.

Mitochondrial MPTP: A Novel Target of Ethnomedicine for Stroke Treatment by Apoptosis Inhibition

Mammalian mitochondrial permeability transition pore (MPTP), across the inner and outer membranes of mitochondria, is a nonspecific channel for signal transduction or material transfer between mitochondrial matrix and cytoplasm such as maintenance of Ca²⁺ homeostasis, regulation of oxidative stress signals, and protein translocation evoked by some of stimuli. Continuous MPTP opening has been proved to stimulate neuronal apoptosis in ischemic stroke. Meanwhile, inhibition of MPTP overopening-induced apoptosis has shown excellent efficacy in the treatment of ischemic stroke. Among of which, the potential molecular mechanisms of drug therapy for stroke has also been gradually revealed by researchers. The characteristics of multi-components or multi-targets for ethnic drugs also provide the possibility to treat stroke from the perspective of mitochondrial MPTP. The advantages mentioned above make it necessary for us to explore and clarify the new perspective of ethnic medicine in treating stroke and to determine the specific molecular mechanisms through advanced technologies as much as possible. In this review, we attempt to uncover the relationship between abnormal MPTP opening and neuronal apoptosis in ischemic stroke. We further summarized currently authorized drugs, ethnic medicine prescriptions, herbs, and identified monomer compounds for inhibition of MPTP overopening-induced ischemic neuron apoptosis. Finally, we strive to provide a new perspective and enlightenment for ethnic medicine in the prevention and treatment of stroke by inhibition of MPTP overopening-induced neuronal apoptosis.

Therapeutic Potential and Effective Components of the Chinese Herb Gardeniae Fructus in the Treatment of Senile Disease

Gardeniae fructus (GF), an evergreen Rubiaceae shrub, is one of the most commonly used Chinese herbs in traditional Chinese medicine (TCM) and has been used for over a thousand years. It is usually prescribed for the treatment of brain aging, vascular aging, bone and joint aging, and other age-related diseases. It has been demonstrated that several effective compounds of GF, such as geniposide, genipin and crocin, have neuroprotective or related activities which are involved in senile disease treatment. These bioactivities include the mitochondrion dysfunction, antioxidative activity, apoptosis regulation and an anti-inflammatory activity, which related to multiple signaling pathways such as the nuclear factor-κB pathway, AMP-activated protein kinase signaling pathway, and the mitogen-activated protein kinase pathway. To lay the ground for fully elucidating the potential mechanisms of GF in treating age-related pathologies, we summarized the available research conducted in the last fifteen years about GF and its effective components, which have been studied in vivo and in vitro

Current pharmacological developments in 2,3,4',5-tetrahydroxystilbene 2-O-β-D-glucoside (TSG)

2,3,4',5-tetrahydroxystilbene 2-O-β-D-glucoside (TSG), a resveratrol analog with glucoside, is purified from a traditional Chinese herbal medicine polygonum multiflorum. It has been extensively studied in last decade and known to exert strong anti-inflammatory, anti-oxidative, anti-apoptotic, and free radical scavenging activities, and therefore has been listed as a potential agent for disease therapies. Recent studies extend well-beyond effects of TSG on the injury of neurons, cardiomyocytes and endothelial cells, and report important functions of TSG in a lot of pathophysiological conditions. For example, TSG has been shown to prevent the production of pro-inflammatory cytokines in microglia and macrophages in vitro, and ameliorate pro-inflammatory responses in animal models with neurodegeneration, atherosclerosis, and rat paw or ear oedema. TSG can prevent the proliferation of vascular smooth cells, gastrointestinal dysfunctions, platelet aggregation, osteoblastic injury, diabetic nephropathy and melanogenesis. TSG is also indicated to facilitate long-term potentiation and learning and memory in both normal and pathological conditions. These effects to some extent enrich the understanding about the role of TSG in disease prevention and therapy. However, to date, we still have no outlined knowledges about the pharmacological effects of TSG, though the role of TSG in aging and Alzheimer's disease has been reviewed in recent years. Here, we summarize the current pharmacological developments of TSG as well as its possible mechanisms in disease prevention and therapy, aiming to push the understanding about the protective role of TSG as well as its preclinical assessment of novel applications.

Natural products against Alzheimer's disease: Pharmaco-therapeutics and biotechnological interventions

Alzheimer's disease (AD) is a severe, chronic and progressive neurodegenerative disease associated with memory and cognition impairment ultimately leading to death. It is the commonest reason of dementia in elderly populations mostly affecting beyond the age of 65. The pathogenesis is indicated by accumulation of the amyloid-beta (Aβ) plaques and neurofibrillary tangles (NFT) in brain tissues and hyperphosphorylation of tau protein in neurons. The main cause is considered to be the formation of reactive oxygen species (ROS) due to oxidative stress. The current treatment provides only symptomatic relief by offering temporary palliative therapy which declines the rate of cognitive impairment associated with AD. Inhibition of the enzyme acetylcholinesterase (AChE) is considered as one of the major therapeutic strategies offering only symptomatic relief and moderate disease-modifying effect. Other non-cholinergic therapeutic approaches include antioxidant and vitamin therapy, stem cell therapy, hormonal therapy, use of antihypertensive or lipid-lowering medications and selective phosphodiesterase (PDE) inhibitors, inhibition of β-secretase and γ-secretase and Aβ aggregation, inhibition of tau hyperphosphorylation and intracellular NFT, use of nonsteroidal anti-inflammatory drugs (NSAIDs), transition metal chelators, insulin resistance drugs, etanercept, brain-derived neurotrophic factor (BDNF) etc. Medicinal plants have been reported for possible anti-AD activity in a number of preclinical and clinical trials. Ethnobotany, being popular in China and in the Far East and possibly less emphasized in Europe, plays a substantial role in the discovery of anti-AD agents from botanicals. Chinese Material Medica (CMM) involving Chinese medicinal plants has been used traditionally in China in the treatment of AD. Ayurveda has already provided numerous lead compounds in drug discovery and many of these are also undergoing clinical investigations. A number of medicinal plants either in their crude forms or as isolated compounds have exhibited to reduce the pathological features associated with AD. In this present review, an attempt has been made to elucidate the molecular mode of action of various plant extracts, phytochemicals and traditional herbal formulations investigated against AD as reported in various preclinical and clinical tests. Herbal synergism often found in polyherbal formulations were found effective to combat disease heterogeneity as found in complex pathogenesis of AD. Finally a note has been added to describe biotechnological improvement, genetic and genomic resources and mathematical and statistical techniques for empirical model building associated with anti-AD plant secondary metabolites and their source botanicals.

Tong Luo Jiu Nao, a Chinese Medicine Formula, Reduces Inflammatory Stress in a Mouse Model of Alzheimer's Disease

AIM

The aim of this study is to extend the molecular mechanism of Tong Luo Jiu Nao (TLJN) for Alzheimer's disease (AD), which is a modern Chinese formula that has been used to treat AD.

METHODS

The senescence-accelerated mouse prone 8 strain (SAMP8) is one of the most appropriate models to study the mechanism that underlies AD. The levels of plasma amyloid β (Aβ) and the Aβ deposits were measured using enzyme-linked immunosorbent assay and immunohistochemistry. Immunoblotting was used to observe the effect of TLJN on inflammatory mediator expression in an senescence-accelerated mouse model of AD.

RESULTS

Our data showed that the TLJN-treated groups exhibited a reduction in plasma Aβ levels and reduced Aβ expression. Moreover, TLJN effectively attenuated Aβ-induced activation of extracellular signal-regulated kinase and c-Jun N-terminal kinases and blocked changes in inflammatory mediator expression.

CONCLUSION

These data suggest that TLJN might have protective effects and could potentially act to attenuate inflammatory stress in the pathogenesis of AD.

Geniposide attenuates inflammatory response by suppressing P2Y14 receptor and downstream ERK1/2 signaling pathway in oxygen and glucose deprivation-induced brain microvascular endothelial cells

ETHNOPHARMACOLOGICAL RELEVANCE

Fructus gardenia is widely used for treatment of stroke and infectious diseases in Chinese medicine. Geniposide is the key bioactive compound related to the pharmacodynamic actions of gardenia on ischemic stroke. The molecular mechanism by which geniposide improves the ischemic brain injury was observed in the study.

AIM OF THE STUDY

Recent studies showed that geniposide had protective activities against the inflammatory response in ischemic stroke. However, the molecular mechanism of geniposide anti-inflammatory role has not yet been fully elucidated. In this study, we investigated the effect of geniposide on the expression of P2Y14 receptor and downstream signaling pathway in brain microvascular endothelial cells (BMECs).

MATERIALS AND METHODS

An in vitro model of cerebral ischemia in BMECs was established by oxygen-glucose-deprivation (OGD). To further confirm the specific effect of geniposide on P2Y14 receptor and downstream signaling pathways, we set up a UDP-glucose (an agonist of the P2Y14 receptor) stimulated model. After administration of geniposide, the expression of P2Y14 receptor, phosphorylation of RAF-1, mitogen activated protein kinase kinase1/2 (MEK1/2), extracellular signal-regulated kinase 1/2 (ERK1/2), level of interleukin-8 (IL-8), interleukin-1β (IL-1β), monocyte chemotactic protein 1 (MCP-1) in BMECs were determined.

RESULTS

The mRNA and protein expression of P2Y14 in the rat BMECs were up-regulated in OGD-induced injury. After administration of Geniposide, the expression of P2Y14 receptor was significantly down-regulated, the phosphorylation of RAF-1, MEK1/2, ERK1/2 were suppressed. Similar data were obtained in UDP-glc stimulated model. We also observed that geniposide markedly declined the production of IL-8, IL-1β and MCP-1 in OGD-induced BMECs.

CONCLUSION

Geniposide exerted anti-inflammatory effects by interfering with the expression of P2Y14 receptor, which subsequently inhibits the downstream ERK1/2 signaling pathways and the release of the pro-inflammatory cytokines IL-8, MCP-1, IL-1β. Therefore, this study provides the evidence for gardenia's clinical application in cerebral ischemia.

Triterpenes from the exudate of Gardenia urvillei

A cycloartane gardurvilleic acid, three 3,4-seco-cycloartanes securvienol, secodienurvilleic acid, securvitriol, a 3,4;9,10-seco-cycloartane gardheptlactone, two dammaranes urvilone, urvilol, along with eight known cycloartanes and 3,4-seco-cycloartanes and four known dammaranes have been isolated from the bud exudate of Gardenia urvillei, an endemic tree to the New Caledonian dry forest. Two other dammarane derivatives have been obtained by semisynthesis. The structures of the original compounds were determined by spectroscopic methods and chemical correlations. In association with previously published data, the description of oxidized side-chains in position 17 are now available for two couples of diastereoisomers. Evaluation of anti-parasite activity and cytotoxicity has shown noticeable results for some of the isolated triterpenes.

Reduced risk of stroke in patients with cardiac arrhythmia receiving traditional Chinese medicine: A nationwide matched retrospective cohort study

OBJECTIVE

Patients with cardiac arrhythmia were more likely to develop stroke than general population. The therapeutic effect of traditional Chinese medicine (TCM) on the risk of stroke in patients with cardiac arrhythmia was unknown. The aim of this study is to investigate the risk of stroke in patients with cardiac arrhythmia receiving TCM.

METHODS

From the one million cohort of the Taiwan's National Health Insurance Research Database, we identified cohort of cardiac arrhythmia included 2029 patients who received TCM treatment in 2000-2004. The matching methods with propensity score was used to select 2029 appropriate control cohort for comparison. Incident events of stroke were identified during the follow-up period at the end of 2010. Cox proportional hazard model was used to calculate adjusted hazard ratios and 95% confidence intervals of stroke associated with TCM treatment.

RESULTS

During the follow-up period, patients with cardiac arrhythmia who underwent TCM treatment (11.4 per 1000 person-years) had a lower incidence of new-onset stroke than those without TCM treatment (17.7 per 1000 person-years), with an HR of 0.62 (95% CI=0.50-0.78). The association between TCM treatment and decreased new-onset stroke was both significant in women and men. The young patients aged 45-54 years who received TCM had the lowest risk of stroke (HR=0.48, 95% CI=0.27-0.87).

CONCLUSIONS

Receiving TCM treatment was associated with a lower risk of stroke in patients with cardiac arrhythmia. However, this study was limited by lack of information regarding lifestyles, biochemical profiles, the dose of herbal medicine, and acupuncture points used in treatments.

Synergistic Use of Geniposide and Ginsenoside Rg1 Balance Microglial TNF-α and TGF-β1 following Oxygen-Glucose Deprivation In Vitro: A Genome-Wide Survey

Ischemia-activated microglia are like a double-edged sword, characterized by both neurotoxic and neuroprotective effects. The aim of this study was to reveal the synergistic effect of geniposide and ginsenoside Rg1 based on tumor necrosis factor- (TNF-) α and transforming growth factor- (TGF-) β1 balance of microglia. BV2 microglial cells were divided into 5 groups: control, model (oxygen-glucose deprivation (OGD)), geniposide-treated, ginsenoside-Rg1-treated, and combination-treated. A series of assays were used to detect on (i) cell viability; (ii) NO content; (iii) expression (content) of TNF-α and TGF-β1; and (iv) gene expression profiles. The results showed that integrated use of geniposide and ginsenoside Rg1 significantly inhibited NO level and protected cell viability, improved the content and expression of TGF-β1, and reduced the content and expression of TNF-α. Separated use of geniposide or ginsenoside Rg1 showed different effects at different emphases. Next-generation sequencing showed that Fcγ-receptor-mediated phagocytosis pathway played a key regulatory role in the balance of TNF-α and TGF-β1 when cotreated with geniposide and ginsenoside Rg1. These findings suggest that synergistic drug combination of geniposide and ginsenoside Rg1 in the treatment of stroke is a feasible avenue for the application.

Efficacy and Safety of Panax notoginseng Saponin Therapy for Acute Intracerebral Hemorrhage, Meta-Analysis, and Mini Review of Potential Mechanisms of Action

Intracranial/intracerebral hemorrhage (ICH) is a leading cause of death and disability in people with traumatic brain injury (TBI) and stroke. No proven drug is available for ICH. Panax notoginseng (total saponin extraction, PNS) is one of the most valuable herb medicines for stroke and cerebralvascular disorders in China. We searched for randomized controlled clinical trials (RCTs) involving PNS injection to treat cerebral hemorrhage for meta-analysis from various databases including the Chinese Stroke Trials Register, the trials register of the Cochrane Complementary Medicine Field, the Cochrane Central Register of Controlled Trials, MEDLINE, Chinese BioMedical disk, and China Doctorate/Master Dissertations Databases. The quality of the eligible trials was assessed by Jadad’s scale. Twenty (20) of the 24 identified randomized controlled trials matched the inclusive criteria including 984 ICH patients with PNS injection and 907 ICH patients with current treatment (CT). Compared to the CT groups, PNS-treated patients showed better outcomes in the effectiveness rate (ER), neurological deficit score, intracranial hematoma volume, intracerebral edema volume, Barthel index, the number of patients died, and incidence of adverse events. Conclusion: PNS injection is superior to CT for acute ICH. A review of the literature shows that PNS may exert multiple protective mechanisms against ICH-induced brain damage including hemostasis, anti-coagulation, anti-thromboembolism, cerebral vasodilation, invigorated blood dynamics, anti-inflammation, antioxidation, and anti-hyperglycemic effects. Since vitamin C and other brain cell activators (BCA) that are not considered common practice were also used as parts of the CT in several trials, potential PNS and BCA interactions could exist that may have made the effect of PNS therapy less or more impressive than by PNS therapy alone. Future PNS trials with and without the inclusion of such controversial BCAs as part of the CT could clarify the situation. As PNS has a long clinical track record in Asia, it could potentially become a therapy option to treat ICH in the US and Europe. Further clinical trials with better experimental design could determine the long-term effects of PNS treatment for TBI and stroke.