Neuroprotective effect of HT008-1, a prescription of traditional Korean medicine, on transient focal cerebral ischemia model in rats

Scutellaria incarnata Vent. root extract and isolated phenylethanoid glycosides are neuroprotective against C2-ceramide toxicity

ETHNOPHARMACOLOGICAL RELEVANCE

Neuronal death is a central process in neurodegenerative diseases and represents a therapeutic challenge for their prevention and treatment. Scutellaria incarnata Vent. roots are used traditionally in Colombia for central nervous system conditions including those affecting cognitive functions, but their chemistry and neuroprotective action remain to be explored to understand the scientific basis for their medicinal uses. In this study, S. incarnata roots are investigated to assess whether they have neuroprotective effects that could provide some explanation for their traditional use in neurodegenerative diseases.

AIM OF THE STUDY

To evaluate the neuroprotective effect of S. incarnata roots and its chemical constituents against C₂-ceramide-induced cell death in Cath.-a-differentiated (CAD) cells.

MATERIALS AND METHODS

S. incarnata root ethanol extract was fractionated and compounds were isolated by column chromatography; their structures were elucidated by nuclear magnetic resonance spectroscopy, mass spectrometry and infrared spectroscopy. The cytotoxic and neuroprotective effects against C₂-ceramide of S. incarnata root extract, fractions and isolated compounds were assessed in CAD cells.

RESULTS

S. incarnata root extract and its n-butanol fraction were not cytotoxic but showed neuroprotective effects against C₂-ceramide toxicity in CAD cells. The phenylethanoid glycosides incarnatoside (isolated for the first time) and stachysoside C (12.5, 25 and 50 μg/mL) from S. incarnata roots also protected CAD cells against C₂-ceramide without inducing cytotoxic effects.

CONCLUSION

The observed neuroprotective effects of S. incarnata root extract and isolated phenylethanoid glycosides in CAD cells provide an ethnopharmacological basis for the traditional use of this species in Colombia for central nervous system disorders.

A review of Acanthopanax senticosus (Rupr and Maxim.) harms: From ethnopharmacological use to modern application

ETHNOPHARMACOLOGICAL RELEVANCE

Acanthopanax senticosus (AS), previously classified as Eleutherococcus senticosus, is one of the most commonly used herbs in the Chinese materia medica. However, there is currently no comprehensive review summarising advances in AS research. AS has been used as a functional food and in various preparations since ancient times, to invigorate the liver and kidneys, replenish vitality, strengthen the bones, stimulate appetite, and improve memory. It is widely used in countries such as China, Korea, Japan, and Russia, for specific pharmacologic effects, although it contains various chemical components that ensure its broad-spectrum effect. Its chemical constituents mainly include glycosides and flavonoids. Over the past several decades, researchers worldwide have conducted systematic investigations on this herb. AS has positive pharmacological effects on the cardiovascular, central nervous, and immune systems. Representative pathways stimulated by AS are related to neuroactive ligand-receptor interactions, cancer, and phosphatidylinositol 3 kinase/protein kinase B signalling. Importantly, AS is safe and exerts no significant adverse effects at normal doses.

AIM OF THE STUDY

To provide comprehensive insights into the ethnobotany, medicinal uses, chemical composition, pharmacological activity, and toxicology of AS to aid its future development and utilisation.

MATERIALS AND METHODS

Information about AS was collected from various sources, including classic books about Chinese herbal medicine and scientific databases including scientific journals, books, and pharmacopoeia. We discuss the ethnopharmacology of AS from 1965 to 2020 and summarise the knowledge of AS phytochemicals, pharmacological activity, quality control, and toxicology.

CONCLUSIONS

From the current literature, we conclude that AS is a promising dietary Chinese herb with various potential applications owing to its multiple therapeutic effects.

Evaluation of the Antidepressant Effect of the Functional Beverage Containing Active Peptides, Menthol and Eleutheroside and Investigation of Its Mechanism of Action in Mice

Research background

Depression has become a global threat to human health. In order to solve it, researchers have conducted multi-faceted studies including diet. Many food-derived bioactive substances have shown antidepressant effects. However, there are few studies on the design of industrialized food with antidepressant effect. This study aims to evaluate the antidepressant effect of a functional beverage made from several ingredients with potential antidepressant function and investigate its antidepressant mechanisms.

Experimental approach

The beverage consists of peppermint oil, active peptides derived from bovine milk casein and Acanthopanax senticosus extract (ASE) whose active ingredient is eleutheroside. Different amounts of ASE were evaluated to determine the optimal concentration of eleutheroside in this functional beverage to deliver the best antidepressant effect through extensive behavioral testing, including preliminary acute stress experiments and further chronic unpredictable mild stress test.

Results and conclusions

The results demonstrated that the beverage with 15 mg/kg of eleutheroside could significantly reduce the mice’s immobility time of tail suspension test and forced swimming test, recover mice’s sucrose preference and behavior changes in the open field test, improve the contents of dopamine, norepinephrine, 5-hydroxytryptamine and the activity of superoxide dismutase and reduce the content of malondialdehyde in mice’s brains, which indicated that the improvement of monoamine neurotransmitter systems and antioxidation was one potential mechanism of antidepressant action.

Novelty and scientific contribution

This study provides a design of antidepressant functional beverage and an efficient way for the prevention and treatment of depression.

Aging Systemic Milieu Impairs Outcome after Ischemic Stroke in Rats

Compelling evidence indicates that factors in the blood can profoundly reverse aging-related impairments, as exposure of aged mice to young blood rejuvenates adult stem cell function, improves cognition, and ameliorates cardiac hypertrophy. Systemic factors from mice can also extend the life span of a partner exposed to a lethal treatment or disease. These findings suggest that the systemic milieu of a healthy young partner may be beneficial for an aged organism. However, it is unknown whether a healthy young systemic milieu can improve functional recovery after ischemic stroke. Intraperitoneal administration of young plasma into aged rats after ischemic stroke induced by distal middle cerebral artery occlusion (dMCAO) reduced infarct volume and motor impairment, compared with vehicle group. On the contrary, intraperitoneal administration of plasma from aged rats into young ischemic rats worsened brain injury and motor deficits. Using a proteomic approach, we found that haptoglobin levels were significantly increased in serum of aged rats and that intraperitoneal administration of haptoglobin impaired outcome after ischemic stroke in young rats. Our data suggest that the aging systemic milieu plays a critical role in functional outcome after ischemic stroke.

Application of Ultra-performance Liquid Chromatography with Time-of-Flight Mass Spectrometry for the Rapid Analysis of Constituents and Metabolites from the Extracts of Acanthopanax senticosus Harms Leaf

Acanthopanax senticosus (Rupr and Maxim) Harms (AS), a member of Araliaceae family, is a typical folk medicinal herb, which is widely distributed in the Northeastern part of China. Due to lack of this resource caused by the extensive use of its root, this work studied the chemical constituents of leaves of this plant with the purpose of looking for an alternative resource. In this work, a fast and optimized ultra-performance liquid chromatography method with quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS) has been developed for the analysis of constituents in leaves extracts. A total of 131 compounds were identified or tentatively characterized including triterpenoid saponins, phenols, flavonoids, lignans, coumarins, polysaccharides, and other compounds based on their fragmentation behaviors. Besides, a total of 21 metabolites were identified in serum in rats after oral administration, among which 12 prototypes and 9 metabolites through the metabolic pathways of reduction, methylation, sulfate conjugation, sulfoxide to thioether and deglycosylation. The coupling of UPLC-QTOF-MS led to the in-depth characterization of the leaves extracts of AS both in vitro and in vivo on the basis of retention time, mass accuracy, and tandem MS/MS spectra. It concluded that this analytical tool was very valuable in the study of complex compounds in medicinal herb.

Protective Effects of Dihydrocaffeic Acid, a Coffee Component Metabolite, on a Focal Cerebral Ischemia Rat Model

We recently reported the protective effects of chlorogenic acid (CGA) in a transient middle cerebral artery occlusion (tMCAo) rat model. The current study further investigated the protective effects of the metabolites of CGA and dihydrocaffeic acid (DHCA) was selected for further study after screening using the same tMCAo rat model. In the current study, tMCAo rats (2 h of MCAo followed by 22 h of reperfusion) were injected with various doses of DHCA at 0 and 2 h after onset of ischemia. We assessed brain damage, functional deficits, brain edema, and blood-brain barrier damage at 24 h after ischemia. For investigating the mechanism, in vitro zymography and western blotting analysis were performed to determine the expression and activation of matrix metalloproteinase (MMP)-2 and -9. DHCA (3, 10, and 30 mg/kg, i.p.) dose-dependently reduced brain infarct volume, behavioral deficits, brain water content, and Evans Blue (EB) leakage. DHCA inhibited expression and activation of MMP-2 and MMP-9. Therefore, DHCA might be one of the important metabolites of CGA and of natural products, including coffee, with protective effects on ischemia-induced neuronal damage and brain edema.

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.

Epigenetic reactivation of Nrf2 in murine prostate cancer TRAMP C1 cells by natural phytochemicals Z-ligustilide and Radix angelica sinensis via promoter CpG demethylation

Cancer development has been linked to epigenetic modifications of cancer oncogenes and tumor suppressor genes; in advanced metastatic cancers, severe epigenetic modifications are present. We previously demonstrated that the progression of prostate tumors in TRAMP mice is associated with methylation silencing of the Nrf2 promoter and a reduced level of transcription of Nrf2 and Nrf2 target genes. Radix Angelicae Sinensis (RAS; Danggui) is a medicinal herb and health food supplement that has been widely used in Asia for centuries. Z-Ligustilide (Lig) is one of the bioactive components of RAS. We investigated the potential of Lig and RAS to restore Nrf2 gene expression through epigenetic modification in TRAMP C1 cells. Lig and RAS induced the mRNA and protein expression of endogenous Nrf2 and Nrf2 downstream target genes, such as HO-1, NQO1, and UGT1A1. Bisulfite genomic sequencing revealed that Lig and RAS treatment decreased the level of methylation of the first five CpGs of the Nrf2 promoter. A methylation DNA immunoprecipitation assay demonstrated that Lig and RAS significantly decreased the relative amount of methylated DNA in the Nrf2 gene promoter region. Lig and RAS also inhibited DNA methyltransferase activity in vitro. Collectively, these results suggest that Lig and RAS are able to demethylate the Nrf2 promoter CpGs, resulting in the re-expression of Nrf2 and Nrf2 target genes. Epigenetic modifications of genes, including Nrf2, may therefore contribute to the overall health benefits of RAS, including the anticancer effect of RAS and its bioactive component, Lig.

Acanthopanax senticosus exerts neuroprotective effects through HO-1 signaling in hippocampal and microglial cells

Extracts of Acanthopanax senticosus, a traditional herb commonly found in Northeastern Asia, are used for treating neurodegenerative disorders such as ischemia and depression. However, the mechanisms of its neuroinflammatory and cytoprotective effects have not been investigated. We examined the mechanism of A. senticosus activity in anti-neuroinflammatory and neuroprotective processes. HO-1 is an inducible enzyme present in most cell lines. ASE increased HO-1 expression, which reduced LPS-induced nitric oxide/ROS production in BV2 cells. Moreover, the induction of HO-1 expression protected cells against glutamate-induced neuronal cell death. Activation of the p38-CREB pathway and translocation of Nrf2 are strongly involved in ASE-induced HO-1 expression. Our results showed that ASE-induced HO-1 expression through the p38-CREB pathway plays an important role in the generation of anti-neuroinflammatory and neuroprotective responses. ASE also increases the translocation of Nrf2 to regulate HO-1 expression. Furthermore, our results indicate that ASE serves as a potential therapeutic agent for neuronal disorders.

Chlorogenic acid ameliorates brain damage and edema by inhibiting matrix metalloproteinase-2 and 9 in a rat model of focal cerebral ischemia

Chlorogenic acid (CGA) has been reported to have various beneficial effects on the cardiovascular and central nervous systems. The purpose of the current study was to investigate whether CGA has protective effects against cerebral ischemia and whether these effects are due to modification of brain edema-related vascular factors. In a rat model of transient middle cerebral artery occlusion (MCAo, 2h of occlusion followed by 22 h of reperfusion), we measured infarct volume and performed behavioral test to evaluate the effects of CGA on brain damage and sensory-motor functional deficits. Brain water content and Evans blue extravasation were measured to evaluate brain edema and blood brain barrier (BBB) damage. Lipid peroxidation (LPO) and the expressions and activities of matrix metalloproteinase (MMP)-2 and MMP-9 were measured to investigate the mechanisms of action. Intraperitoneal injection of CGA (3, 10, and 30 mg/kg) at 0 h and 2h after MCAo dose-dependently reduced infarct volume and sensory-motor functional deficits. It also reduced brain water content and Evans blue extravasation. Mechanistically, CGA reduced LPO and MMPs expressions and activities. These results suggest that CGA reduces brain damage, BBB damage and brain edema by radical scavenging activity and the inhibitory effects on MMP-2 and MMP-9.

Protective effects of Galla Rhois, the excrescence produced by the sumac aphid, Schlechtendalia chinensis, on transient focal cerebral ischemia in the rat

Galla Rhois is formed by aphids, primarily Schlechtendalia chinensis Bell (Homoptera: Pemphigidae), on the leaf of sumac, Rhus javanica L. (Sapindales: Anacardiaceae). It is a tannin-rich herb that is widely used in traditional Korean medicine. Its various pharmacological effects, including its radical-scavenging effects, have been reported. The purpose of the current study was to determine if these radical-scavenging effects can be confirmed using in vitro assays and to investigate its neuroprotective effects, optimal dosage, mechanisms, and therapeutic time window in an animal model of stroke. Galla Rhois 85% methanol extract (GRE) exhibited potent and dose-dependent radical-scavenging effects on various radicals. Oral administration of GRE (300 mg/kg) in a transient focal cerebral ischemia rat model (two hours of occlusion followed by 22 hours of reperfusion) reduced the brain infarct volume by 37.5%. It also improved sensory motor function and reduced lipid-peroxidation in middle cerebral artery occlusion. However, it did not have any inhibitory effects on brain edema. The time window study revealed that pre- and co-treatment with GRE had protective effects, but post-treatment with GRE (three or six hours after ischemia) did not have protective effects. In conclusion, GRE had potent radical-scavenging activities and neuroprotective effects in a rat model of stroke when it was pre- and co-administered. The optimal dosage may be around 300 mg/kg for oral administration.

Bioactivities of major constituents isolated from Angelica sinensis (Danggui)

Danggui, also known as Angelica sinensis (Oliv.) Diels (Apiaceae), has been used in Chinese medicine to treat menstrual disorders. Over 70 compounds have been isolated and identified from Danggui. The main chemical constituents of Angelica roots include ferulic acid, Z-ligustilide, butylidenephthalide and various polysaccharides. Among these compounds, ferulic acid exhibits many bioactivities especially anti-inflammatory and immunostimulatory effects; Z-ligustilide exerts anti-inflammatory, anti-cancer, neuroprotective and anti-hepatotoxic effects; n-butylidenephthalide exerts anti-inflammatory, anti-cancer and anti-cardiovascular effects.