p38 MAPK and ERK1/2 pathways are involved in the pro-apoptotic effect of notoginsenoside Ft1 on human neuroblastoma SH-SY5Y cells

Production and pharmaceutical research of minor saponins in Panax notoginseng (Sanqi): Current status and future prospects

Panax notoginseng (Burk.) F.H. Chen is a traditional medicinal herb known as Sanqi or Tianqi in Asia and is commonly used worldwide. It is one of the main raw ingredients of Yunnan Baiyao, Fu fang dan shen di wan, and San qi shang yao pian. It is also a source of cardiotonic pill used to treat cardiovascular diseases in China, Korea, and Russia. Approximately 270 Panax notoginseng saponins have been isolated and identified as the major active components. Although the absorption and bioavailability of saponins are predominantly dependent on the gastrointestinal biotransformation capacity of an individual, minor saponins are better absorbed into the bloodstream and act as active substances than major saponins. Notably, minor saponins are absent or are present in minimal quantities under natural conditions. In this review, we focus on the strategies for the enrichment and production of minor saponins in P. notoginseng using physical, chemical, enzyme catalytic, and microbial methods. Moreover, pharmacological studies on minor saponins derived from P. notoginseng over the last decade are discussed. This review serves as a meaningful resource and guide, offering scholarly references for delving deeper into the exploration of the minor saponins in P. notoginseng.

Notoginsenoside Ft1 inhibits colorectal cancer growth by increasing CD8+ T cell proportion in tumor-bearing mice through the USP9X signaling pathway

The management of colorectal cancer (CRC) poses a significant challenge, necessitating the development of innovative and effective therapeutics. Our research has shown that notoginsenoside Ft1 (Ng-Ft1), a small molecule, markedly inhibits subcutaneous tumor formation in CRC and enhances the proportion of CD8+ T cells in tumor-bearing mice, thus restraining tumor growth. Investigation into the mechanism revealed that Ng-Ft1 selectively targets the deubiquitination enzyme USP9X, undermining its role in shielding β-catenin. This leads to a reduction in the expression of downstream effectors in the Wnt signaling pathway. These findings indicate that Ng-Ft1 could be a promising small-molecule treatment for CRC, working by blocking tumor progression via the Wnt signaling pathway and augmenting CD8+ T cell prevalence within the tumor environment.

Luteoloside Induces G0/G1 Phase Arrest of Neuroblastoma Cells by Targeting p38 MAPK

Luteoloside has shown anti-inflammatory, antiviral, and antitumor properties. However, the effect and mechanism of luteoloside on neuroblastoma cells remain unknown. The proliferation of human neuroblastoma cells (SH-SY5Y and SK-N-AS) treated with different concentrations of luteoloside (0, 12.5, 25, and 50 μM) was detected by the MTT assay and colony formation assay. Cell apoptosis and cell cycle were examined by Hoechst staining and flow cytometry. A subcutaneous tumorigenesis model was established in nude mice to evaluate the effect of luteoloside on tumor growth in vivo. Bioinformatics, molecular docking techniques, and cellular thermal shift assays were utilized to predict the potential targets of luteoloside in neuroblastoma. The p38 MAPK inhibitor SB203580 was used to confirm the role of p38 MAPK. Luteoloside inhibited the proliferation of neuroblastoma cells in vitro and in vivo. Luteoloside slightly induced cellular G0/G1 phase arrest and reduced the expression levels of G0/G1 phase-related genes and the proteins cyclin D1, CDK4, and C-myc, which are downregulated by p38 MAPK pathways. Meanwhile, p38 was identified as the target of luteoloside, and inhibition of p38 MAPK reversed the inhibitory effect of luteoloside on neuroblastoma cells. Luteoloside is a potential anticancer drug for treating neuroblastoma by activating p38 MAPK.

Advance in glycosyltransferases, the important bioparts for production of diversified ginsenosides

Ginsenosides are a series of glycosylated triterpenoids predominantly originated from Panax species with multiple pharmacological activities such as anti-aging, mediatory effect on the immune system and the nervous system. During the biosynthesis of ginsenosides, glycosyltransferases play essential roles by transferring various sugar moieties to the sapogenins in contributing to form structure and bioactivity diversified ginsenosides, which makes them important bioparts for synthetic biology-based production of these valuable ginsenosides. In this review, we summarized the functional elucidated glycosyltransferases responsible for ginsenoside biosynthesis, the advance in the protein engineering of UDP-glycosyltransferases (UGTs) and their application with the aim to provide in-depth understanding on ginsenoside-related UGTs for the production of rare ginsenosides applying synthetic biology-based microbial cell factories in the future.

A rapid and sensitive ultra-high-pressure liquid chromatography-tandem mass spectrometry method for the determination of notoginsenoside Ft1 in rat plasma with application to pharmacokinetic study

Notoginsenoside Ft1 (NGFt1), a dammarane triterpene glycoside isolated from Panax notoginseng, showed potent effective in stimulating platelet aggregation in our previous assay, yet its pharmacokinetic behavior is still unclear. This study describes a rapid and sensitive ultra-high-pressure LC-tandem mass spectrometry assay for determining of NGFt1 in rat plasma. Methanol-mediated precipitation was used for sample pre-treatment. Chromatographic separation was achieved on a C₁₈ column with gradient elution using water and acetonitrile as mobile phase. Determination was obtained using an electrospray ionization source in negative selected reaction monitoring (SRM) mode at the transitions of m/z 915.9 → m/z 783.8 and m/z 799.8 → m/z 637.8 for NGFt1 and internal standard, respectively. The assay was linear over the concentration range 0.25-2500 ng/mL (r > 0.995) with the lower limit of quantification of 0.25 ng/mL. The intra- and inter-day precisions (relative standard deviation, %) ranged 1.65%-9.84% and 2.46%-13.49%, respectively, whereas accuracy (relative recovery, %) ranged from 96.21% to 99.45%, respectively. The recovery ranged from 95.09% to 102.22% and the matrix effect from 98.29% to 100.13%. The analyte was stable under tested storage conditions. The method has been successfully applied to a preclinical pharmacokinetic study in rats after a single intravenous (2 mg/kg) and oral (50 mg/kg) administration.

Traditional uses, chemical diversity and biological activities of Panax L. (Araliaceae): A review

ETHNOPHARMACOLOGICAL RELEVANCE

Panax L. (Araliaceae) is globally-recognized plant resource suitable for the globalization of traditional Chinese medicines. It has traditionally been used as tonic agents in various ethnomedicinal systems of East Asia, especially in China. It is often used to regulate bodily functions and considered as adjuvant therapy for tumor, resuscitation of traumatic hemorrhagic shock, etc. AIM OF THIS REVIEW: This review systematically summarized the information on distributions, botanical characteristics, traditional uses, chemical components and biological activities of the genus Panax, in order to explore and exploit the therapeutic potential of this plant.

MATERIALS AND METHODS

The available information about genus Panax was collected via the online search on Web of Science, Google Scholar, PubMed, Baidu Scholar, Science Direct, China National Knowledge Infrastructure and Springer search. The keywords used include Panax, saponin, secondary metabolites, chemical components, biological activity, pharmacology, traditional medicinal uses, safety and other related words. The Plant List (www.theplantlist.org) and Catalogue of Life: 2019 Annual Checklist (www.catalogueoflife.org/col/) databases were used to provide the scientific names, subspecies classification and distribution information of Panax.

RESULTS

Panax is widely assessed concerning its phytochemistry and biological activities. To date, at least 748 chemical compounds from genus Panax were isolated, including saponins, flavonoids, polysaccharides, steroids and phenols. Among them, triterpenoid saponins and polysaccharides were the representative active ingredients of Panax plants, which have been widely investigated. Modern pharmacological studies showed that these compounds exhibited a wide range of biological activities in vitro and in vivo including antineoplastic, anti-inflammatory, hepatorenal protective, neuroprotective, immunoregulatory, cardioprotective and antidiabetic activities. Many studies also confirmed that the mechanisms of organ-protective were closely related to molecular signaling pathways, the expression of related proteins and antioxidant reactions. To sum up, genus Panax has high medicinal and social value, deserving further investigation.

CONCLUSIONS

The genus Panax is very promising to be fully utilized in the development of nutraceutical and pharmaceutical products. However, there is a lack of in-depth studies on ethnomedicinal uses of Panax plants. In addition, further studies of single chemical component should be performed based on the diversity of chemical structure, significant biological activities and clinical application. If the bioactive molecules and multicomponent interactions are discovered, it will be of great significance to the clinical application of Panax plants. It is an urgent requirement to carry out detailed phytochemical, pharmacology and clinical research on Panax classical prescriptions for the establishment of modern medication guidelines. Exploring the molecular basis of herbal synergistic actions may provide a new understanding of the complex disease mechanisms and accelerate the process of pharmaceutical development.

Toward a better understanding of metabolic and pharmacokinetic characteristics of low-solubility, low-permeability natural medicines

Today, it is very challenging to develop new active pharmaceutical ingredients. Developing good preparations of well-recognized natural medicines is certainly a practical and economic strategy. Low-solubility, low-permeability natural medicines (LLNMs) possess valuable advantages such as effectiveness, relative low cost and low toxicity, which is shown by the presence of popular products on the market. Understanding the in vivo metabolic and pharmacokinetic characteristics of LLNMs contributes to overcoming their associated problems, such as low absorption and low bioavailability. In this review, the structure-based metabolic reactions of LLNMs and related enzymatic systems, cellular and bodily pharmacological effects and metabolic influences, drug-drug interactions involved in metabolism and microenvironmental changes, and pharmacokinetics and dose-dependent/linear pharmacokinetic models are comprehensively evaluated. This review suggests that better pharmacological activity and pharmacokinetic behaviors may be achieved by modifying the metabolism through using nanotechnology and nanosystem in combination with the suitable administration route and dosage. It is noteworthy that novel nanosystems, such as triggered-release liposomes, nucleic acid polymer nanosystems and PEGylated dendrimers, in addition to prodrug and intestinal penetration enhancer, demonstrate encouraging performance. Insights into the metabolic and pharmacokinetic characteristics of LLNMs may help pharmacists to identify new LLNM formulations with high bioavailability and amazing efficacy and help physicians carry out LLNM-based precision medicine and individualized therapies.

Biosynthesis of rare 20(R)-protopanaxadiol/protopanaxatriol type ginsenosides through Escherichia coli engineered with uridine diphosphate glycosyltransferase genes

BACKGROUND

Ginsenosides are known as the principal pharmacological active constituents in Panax medicinal plants such as Asian ginseng, American ginseng, and Notoginseng. Some ginsenosides, especially the 20(R) isomers, are found in trace amounts in natural sources and are difficult to chemically synthesize. The present study provides an approach to produce such trace ginsenosides applying biotransformation through Escherichia coli modified with relevant genes.

METHODS

Seven uridine diphosphate glycosyltransferase (UGT) genes originating from Panax notoginseng, Medicago sativa, and Bacillus subtilis were synthesized or cloned and constructed into pETM6, an ePathBrick vector, which were then introduced into E. coli BL21star (DE3) separately. 20(R)-Protopanaxadiol (PPD), 20(R)-protopanaxatriol (PPT), and 20(R)-type ginsenosides were used as substrates for biotransformation with recombinant E. coli modified with those UGT genes.

RESULTS

E. coli engineered with GT95 syn selectively transfers a glucose moiety to the C20 hydroxyl of 20(R)-PPD and 20(R)-PPT to produce 20(R)-CK and 20(R)-F1, respectively. GTK1- and GTC1-modified E. coli glycosylated the C3-OH of 20(R)-PPD to form 20(R)-Rh2. Moreover, E. coli containing p2GT95synK1, a recreated two-step glycosylation pathway via the ePathBrich, implemented the successive glycosylation at C20-OH and C3-OH of 20(R)-PPD and yielded 20(R)-F2 in the biotransformation broth.

CONCLUSION

This study demonstrates that rare 20(R)-ginsenosides can be produced through E. coli engineered with UTG genes.

Stimulatory effect of icariin on the proliferation of neural stem cells from rat hippocampus

Background

Icariin (ICA), a major ingredient of Epimediumbrevicornum, has various pharmacological activities including central nervous system protective functions such as the improvement of learning and memory function in mice models of Alzheimer’s disease. It has been reported that ICA can promote regeneration of peripheral nerve and functional recovery. The purpose of this study was to investigate the potentiating effect of ICA on the proliferation of rat hippocampal neural stem cells, and explore the possible mechanism involved.

Methods

Primary neural stem cells were prepared from the hippocampus of newly born SD rats, and cells were cultured in special stem cell culture medium. Neural stem cells were confirmed by immunofluorescence detection of nestin, NSE and GFAP expression. The effect of ICA on the growth and proliferation of the neural stem cells was evaluated by 5-ethynyl-2-deoxyuridine (EdU) labeling of proliferating cells, and photomicrographic images of the cultured neural stem cells. Further, the mechanism of ICA-induced cell proliferation of neural stem cells was investigated by analyzing the gene and protein expression of cell cycle related genes cyclin D1 and p21.

Results

The present study showed that icariin promotes the growth and proliferation of neural stem cells from rat hippocampus in a dose-dependent manner. Incubation of cells with icariin resulted in significant increase in the number of stem cell spheres as well as the increased incorporation of EdU when compared with cells exposed to control vehicle. In addition, it was found that icariin-induced effect on neural stem cells is associated with increased mRNA and protein expression of cell cycle genes cyclin D1 and p21.

Conclusions

This study evidently demonstrates the potentiating effect of ICA on neural stem cell growth and proliferation, which might be mediated through regulation of cell cycle gene and protein expression promoting cell cycle progression.

Electronic supplementary material

The online version of this article (10.1186/s12906-018-2095-y) contains supplementary material, which is available to authorized users.

Therapeutic Potential and Cellular Mechanisms of Panax Notoginseng on Prevention of Aging and Cell Senescence-Associated Diseases

Owing to a dramatic increase in average life expectancy, most countries in the world are rapidly entering an aging society. Therefore, extending health span with pharmacological agents targeting aging-related pathological changes, are now in the spotlight of gerosciences. Panax notoginseng (Burk.) F. H. Chen, a species of the genus Panax, has been called the "Miracle Root for the Preservation of Life," and has long been used as a Chinese herb with magical medicinal value. Panax notoginseng has been extensively employed in China to treat microcirculatory disturbances, inflammation, trauma, internal and external bleeding due to injury, and as a tonic. In recent years, with the deepening of the research pharmacologically, many new functions have been discovered. This review will introduce its pharmacological function on lifespan extension, anti-vascular aging, anti-brain aging, and anti-cancer properties, aiming to lay the ground for fully elucidating the potential mechanisms of Panax notoginseng's anti-aging effect to promote its clinical application.

The Role of Unfolded Protein Response and Mitogen-Activated Protein Kinase Signaling in Neurodegenerative Diseases with Special Focus on Prion Diseases

Prion diseases are neurodegenerative pathologies characterized by the accumulation of a protease-resistant form of the cellular prion protein named prion protein scrapie (PrP^Sc) in the brain. PrP^Sc accumulation in the endoplasmic reticulum (ER) result in a dysregulated calcium (Ca²⁺) homeostasis and subsequent initiation of unfolded protein response (UPR) leading to neuronal dysfunction and apoptosis. The molecular mechanisms for the transition between adaptation to ER stress and ER stress-induced apoptosis are still unclear. Mitogen-activated protein kinases (MAPKs) are serine/threonine protein kinases that rule the signaling of many extracellular stimuli from plasma membrane to the nucleus. However the identification of numerous points of cross talk between the UPR and MAPK signaling pathways may contribute to our understanding of the consequences of ER stress in prion diseases. Indeed the MAPK signaling network is known to regulate cell cycle progression and cell survival or death responses following a variety of stresses including misfolded protein response stress. In this article, we review the UPR signaling in prion diseases and discuss the triad of MAPK signaling pathways. We also describe the role played by MAPK signaling cascades in Alzheimer’s (AD) and Parkinson’s disease (PD). We will also overview the mechanisms of cell death and the role of MAPK signaling in prion disease progression and highlight potential avenues for therapeutic intervention.

Phytochemistry and Anticancer Potential of Notoginseng

Asian ginseng, American ginseng, and notoginseng are three major species in the ginseng family. Notoginseng is a Chinese herbal medicine with a long history of use in many Oriental countries. This botanical has a distinct ginsenoside profile compared to other ginseng herbs. As a saponin-rich plant, notoginseng could be a good candidate for cancer chemoprevention. However, to date, only relatively limited anticancer studies have been conducted on notoginseng. In this paper, after reviewing its anticancer data, phytochemical isolation and analysis of notoginseng is presented in comparison with Asian ginseng and American ginseng. Over 80 dammarane saponins have been isolated and elucidated from different plant parts of notoginseng, most of them belonging to protopanaxadiol or protopanaxatriol groups. The role of the enteric microbiome in mediating notoginseng metabolism, bioavailability, and pharmacological actions are discussed. Emphasis has been placed on the identification and isolation of enteric microbiome-generated notoginseng metabolites. Future investigations should provide key insights into notoginseng's bioactive metabolites as clinically valuable anticancer compounds.

Chemical transformation and target preparation of saponins in stems and leaves of Panax notoginseng

Background

Notoginsenoside Ft1 is a promising potential candidate for cardiovascular and cancer disease therapy owing to its positive pharmacological activities. However, the yield of Ft1 is ultralow utilizing reported methods. Herein, an acid hydrolyzing strategy was implemented in the acquirement of rare notoginsenoside Ft1.

Methods

Chemical profiles were identified by ultraperformance liquid chromatography coupled with quadruple-time-of-flight and electrospray ionization mass spectrometry (UPLC-Q/TOF-ESI-MS). The acid hydrolyzing dynamic changes of chemical compositions and the possible transformation pathways of saponins were monitored by ultrahigh-performance LC coupled with tandem MS (UHPLC-MS/MS).

Results and conclusion

Notoginsenoside Ft1 was epimerized from notoginsenoside ST4, which was generated through cleaving the carbohydrate side chains at C-20 of notoginsenosides Fa and Fc, and vina-ginsenoside R7, and further converted to other compounds via hydroxylation at C-25 or hydrolysis of the carbohydrate side chains at C-3 under the acid conditions. High temperature contributed to the hydroxylation reaction at C-25 and 25% acetic acid concentration was conducive to the preparation of notoginsenoside Ft1. C-20 epimers of notoginsenoside Ft1 and ST4 were successfully separated utilizing solvent method of acetic acid solution. The theoretical preparation yield rate of notoginsenoside Ft1 was about 1.8%, which would be beneficial to further study on its bioactivities and clinical application.

Synthesis of Tolmetin Hydrazide-Hydrazones and Discovery of a Potent Apoptosis Inducer in Colon Cancer Cells

Tolmetin hydrazide and a novel series of tolmetin hydrazide-hydrazones 4a-l were synthesized in this study. The structures of the new compounds were determined by spectral (FT-IR, (1)H NMR) methods. N'-[(2,6-Dichlorophenyl)methylidene]-2-[1-methyl-5-(4-methylbenzoyl)-1H-pyrrol-2-yl]acetohydrazide (4g) was evaluated in vitro using the MTT colorimetric method against the colon cancer cell lines HCT-116 (ATCC, CCL-247) and HT-29 (ATCC, HTB-38) to determine growth inhibition and cell viability at different doses. Compound 4g exhibited anti-cancer activity with an IC50 value of 76 μM against colon cancer line HT-29 (ATCC, HTB-38) and did not display cytotoxicity toward control NIH3T3 mouse embryonic fibroblast cells compared to tolmetin. In addition, this compound was evaluated for caspase-3, caspase-8, caspase-9, and annexin-V activation in the apoptotic pathway, which plays a key role in the treatment of cancer. We demonstrated that the anti-cancer activity of this compound was due to the activation of caspase-8 and caspase-9 involved in the apoptotic pathway. In addition, in this study, we investigated the catalytical effect of COX on the HT-29 cancer line, the apoptotic mechanism, and the moleculer binding of tolmetin and compound 4g on the COX enzyme active site.

NSC-87877 inhibits DUSP26 function in neuroblastoma resulting in p53-mediated apoptosis

Dual specificity protein phosphatase 26 (DUSP26) is overexpressed in high-risk neuroblastoma (NB) and contributes to chemoresistance by inhibiting p53 function. In vitro, DUSP26 has also been shown to effectively inhibit p38 MAP kinase. We hypothesize that inhibiting DUSP26 will result in decreased NB cell growth in a p53 and/or p38-mediated manner. NSC-87877 (8-hydroxy-7-[(6-sulfo-2-naphthyl)azo]-5-quinolinesulfonic acid), a novel DUSP26 small molecule inhibitor, shows effective growth inhibition and induction of apoptosis in NB cell lines. NB cell lines treated with small hairpin RNA (shRNA) targeting DUSP26 also exhibit a proliferation defect both in vitro and in vivo. Treatment of NB cell lines with NSC-87877 results in increased p53 phosphorylation (Ser37 and Ser46) and activation, increased activation of downstream p38 effector proteins (heat shock protein 27 (HSP27) and MAP kinase-activated protein kinase 2 (MAPKAPK2)) and poly ADP ribose polymerase/caspase-3 cleavage. The cytotoxicity resulting from DUSP26 inhibition is partially reversed by knocking down p53 expression with shRNA and also by inhibiting p38 activity with SB203580 (4-[4-(4-fluorophenyl)-2-(4-methylsulfinylphenyl)-1H-imidazol-5-yl]pyridine). In an intrarenal mouse model of NB, NSC-87877 treatment results in decreased tumor growth and increased p53 and p38 activity. Together, these results suggest that DUSP26 inhibition with NSC-87877 is an effective strategy to induce NB cell cytotoxicity in vitro and in vivo through activation of the p53 and p38 mitogen-activated protein kinase (MAPK) tumor-suppressor pathways.

Enzymatic transformation of vina-ginsenoside R₇ to rare notoginsenoside ST-4 using a new recombinant glycoside hydrolase from Herpetosiphon aurantiacus

An eco-friendly and convenient preparation method for notoginsenoside ST-4 has been established by completely transforming vina-ginsenoside R7 using a recombinant glycosidase hydrolyzing enzyme (HaGH03) from Herpetosiphon aurantiacus. This enzyme specifically hydrolyzed the glucose at the C-20 position but not the external xylose or two inner glucoses at position C-3. Protein sequence BLAST revealed that HaGH03, composed of 749 amino acids and presumptively listed as a member of the family 3 glycoside hydrolases, has highest identity (48 %) identity with a thermostable β-glucosidase B, which was not known of any functions for ginsenoside transformation. The steady state kinetic parameters for purified HaGH03 measured against p-nitrophenyl β-D-glucopyranoside and vina-ginsenoside R7 were K M = 5.67 ± 0.24 μM and 0.59 ± 0.23 mM, and k cat = 69.2 ± 0.31/s and 2.15 ± 0.46/min, respectively. HaGH03 converted 2.5 mg/mL of vina-ginsenoside R7 to ST-4 with a molar yield of 100 % and a space-time yield of 104 mg/L/h in optimized conditions. These results underscore that HaGH03 has much potential for the effective preparation of target ginsenosides possessing valuable pharmacological activities. This is the first report identifying an enzyme that has the ability to transform vina-ginsenoside R7 and provides an approach to preparing rare notoginsenoside ST-4.

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.