Memory enhancing and neuroprotective effects of selected ginsenosides

Efficacy and safety of YOXINTINE for depression: A double-blinded, randomized, placebo-controlled, phase 2 clinical trial

BACKGROUND

YOXINTINE contains >98 % of 20(S)-protopanaxadial (PPD), a metabolic product of ginsenosides with pre-clinical neuroprotective activity. Animal experiments and previous studies have shown that PPD has good antidepressant effect and safety.

PURPOSE

To evaluate YOXINTINE in treating depression compared with a placebo in Chinese patients.

STUDY DESIGN

This was a multicenter, double-blinded, randomized, placebo-controlled, phase 2 clinical trial.

METHODS

The study included 178 randomized (1:1:1) Chinese patients with depression. Patients were randomly assigned to receive oral YOXINTINE at doses of 200 or 400 mg or a placebo administered twice daily for 8 weeks. The primary outcome was assessed by measuring changes in the Montgomery-Asberg Depression Rating Scale (MADRS) total score. All adverse reactions were recorded. All demographic and baseline characteristics were comparable.

RESULTS

The changes in MADRS total scores from baseline were -10.43 for the placebo group, -16.24 for the 200 mg YOXINTINE group, and -13.60 for the 400 mg YOXINTINE group. The differences in MADRS total score changes compared with the placebo were -5.81 (95 % CI: -7.69, -3.92; P < 0.0001) and -3.17 (95 % CI: -5.08, -1.25; P = 0.0013) for the 200 mg and 400 mg groups, respectively. The results indicated a significantly greater MADRS score reduction in the 200 mg group (P = 0.0058, 95 % CI: 0.78, 4.51). Adverse event incidence was comparable among all groups.

CONCLUSION

Oral YOXINTINE is safe and significantly improves depressive symptoms. PPD may exhibit antidepressant properties through mechanisms distinct from monoamine reuptake inhibition.

REGISTRATION NUMBER

ChiCTR2300070568.

How to More Effectively Obtain Ginsenoside Rg5: Understanding Pathways of Conversion

Ginsenoside Rg5, a relatively uncommon secondary ginsenoside, exhibits notable pharmacological activity and is commonly hypothesized to originate from the dehydration of Rg3. In this work, we compared different conversion pathways using Rb1, R-Rg3 and S-Rg3 as the raw material under simple acid catalysis. Interestingly, the results indicate that the conversion follows this reaction activity order Rb1 > S-Rg3 > R-Rg3, which is contrary to the common understanding of Rg5 obtained from Rg3 by dehydration. Our experimental results have been fully confirmed by theoretical calculations and a NOESY analysis. The DFT analysis reveals that the free energies of S-Rg3 and R-Rg3 in generating carbocation are 7.56 mol/L and 7.57 mol/L, respectively, which are significantly higher than the free energy of 1.81 mol/L when Rb1 generates the same carbocation. This finding aligns with experimental evidence suggesting that Rb1 is more prone to generating Rg5 than Rg3. The findings from the nuclear magnetic resonance (NMR) analysis suggest that the fatty chains (C22-C27) in R-Rg3 and S-Rg3 adopt a Gauche conformation and an anti conformation with C16-C17 and C13-C17, respectively, due to the relatively weak repulsive van der Waals force. Therefore, the configuration of R-Rg3 is more conducive to the formation of intramolecular hydrogen bonds between 20C-OH and 12C-OH, whereas S-Rg3 lacks this capability. Consequently, this also explains the fact that S-Rg3 is more prone to dehydration to generate Rg5 than R-Rg3. Additionally, our research reveals that the synthetic route of Rg5 derived from protopanaxadiol (PPD)-type ginsenosides (including Rb1, Rb2, Rb3, Rc and Rd) exhibits notable advantages in terms of efficacy, purity and yield when compared to the pathway originating from Rg3. Moreover, this study presents a highly effective and practical approach for the extensive synthesis of Rg5, thereby facilitating the exploration of its pharmacological properties and potential application in drug discovery.

Anxiolytic effect of Korean Red Ginseng through upregulation of serotonin and GABA transmission and BDNF expression in immobilized mice

Background

Anxiolytic properties of Korean Red Ginseng (KRG) have been previously reported. However, the exact mechanism(s) of action remains to be elucidated. The present study investigated the effect of KRG on immobilization-induced anxiety-like behaviors in mice and explored the involvement of the serotonin and GABA systems and BDNF in the anxiolytic action.

Methods

Mice were orally administered with KRG (200 mg/kg/day) for 4 weeks and immobilized once daily for 2 h. p-Chlorophenylalanine (p-CPA) was intraperitoneally injected on day 22-28, and flumazenil or bicuculline was injected on day 25-28. After behavioral evaluations, brains were dissected for biochemical analyses.

Results

KRG improved immobilization-induced anxiety-like behaviors in mice, as assessed by the elevated plus maze (EPM) and marble burying tests (MBT). The anxiolytic effect of KRG was comparable to that of fluoxetine, a reference drug clinically used for anxiety disorders. A serotonin synthesis inhibitor, p-CPA, blocked the effect of KRG in the EPM and MBT, indicating the requirement of serotonin synthesis for anxiolytic action. In addition, the anxiolytic effect of KRG was inhibited by bicuculline (a GABA_A antagonist) in MBT, implying the involvement of GABA transmission. Western blotting analyses revealed that KRG upregulated the expression of tryptophan hydroxylase and GABA_A receptor in the brain, which was blocked by p-CPA. Enhanced BDNF expression by KRG in the hippocampus was also indicated to mediate the anxiolytic action of KRG in immobilized mice.

Conclusion

KRG exhibited the anxiolytic effect in immobilized mice by multiple mechanisms of action, involving enhanced serotonin and GABA transmissions and BDNF expression.

Folecitin Isolated from Hypericum oblongifolium Exerts Neuroprotection against Lipopolysaccharide-Induced Neuronal Synapse and Memory Dysfunction via p-AKT/Nrf-2/HO-1 Signalling Pathway

Neurodegenerative diseases, especially Alzheimer's disease (AD), are characterised with neuronal synapse and memory dysfunction, and thus, there is an urgent need to find novel therapeutic medicines that can target different pathways to restore the deficits. In this investigation, we assessed the medicinal potency of folecitin (a flavonoid isolated from Hypericum oblongifolium Wall.) against lipopolysaccharide (LPS)-induced amyloidogenic amyloid beta (Aβ) production pathway-mediated memory impairment in mice. The LPS was administered intraperitonially (i.p.) 250 μg/kg/day for 3 consecutive weeks, followed by the coadministration of folecitin (30 mg/kg/day) with LPS for the last two weeks (2^nd and 3^rd week). The expression of various proteins involved in synapse, neuronal death, and Aβ generation was evaluated using the Western blot approach. Results indicated that folecitin significantly decreased LPS-induced apoptotic proteins; expressed BAX, PARP-1, and caspase-3 proteins; and inhibited BACE1 that cleaves transmembrane amyloid precursor protein and the amyloidogenic Aβ production pathway. Folecitin restored both preneural and postneuronal synapse, accompanied by the improvement in memory impairment. Moreover, folecitin significantly activated endogenous antioxidant proteins Nrf-2 and HO-1 by stimulating the phosphorylation of Akt proteins. These findings indicate that folecitin might be a promising target for developing novel medication to treat neurodegenerative disorders caused by neurotoxins.

Anti-Stroke Chinese Herbal Medicines Inhibit Abnormal Amyloid-β Protein Precursor Processing in Alzheimer's Disease

BACKGROUND

Chinese Herbal Medicines (CHMs), as an important and integral part of a larger system of medicine practiced in China, called Traditional Chinese Medicine (TCM), have been used in stroke therapy for centuries. A large body of studies suggest that some Chinese herbs can help reverse cognitive impairment in stroke patients, while whether these herbs also exert therapeutic benefits for Alzheimer's disease remains to be seen.

OBJECTIVE

To address this issue, we selected four types of CHMs that are commonly prescribed for stroke treatment in clinical practice, namely DengZhanXiXin (D1), TongLuoJiuNao (T2), QingKaiLing (Q3), and HuangQinGan (H4), and tested their effects on amyloid-β protein precursor (AβPP) processing in vitro.

METHODS

AβPP, β-secretase (BACE1), and 99-amino acid C-terminal fragment of AβPP (C99) stably transfected cells were used for the tests of AβPP processing. The production of Aβ, activity of BACE1, neprilysin (NEP), and γ-secretase were assessed by ELISA, RT-PCR, and western blot.

RESULTS

By upregulating BACE1 activity, D1 increased Aβ production whereas decreased the ratio of Aβ 42/Aβ 40; by downregulating BACE1 activity and modulating the expression of γ-secretase, T2 decreased Aβ production and the ratio of Aβ 42/Aβ 40; by downregulating BACE1 activity, Q3 decreased Aβ production; H4 did not change Aβ production due to the simultaneously downregulation of BACE1 and NEP activity.

CONCLUSION

Our study indicates that these four anti-stroke CHMs regulate AβPP processing through different mechanisms. Particularly, T2 with relatively simple components and prominent effect on AβPP processing may be a promising candidate for the treatment of AD.

Neuroprotective Effect and Antioxidant Potency of Fermented Cultured Wild Ginseng Root Extracts of Panax ginseng C.A. Meyer in Mice

Wild ginseng has better pharmacological effects than cultivated ginseng. However, its industrialization is limited by the inability to grow wild ginseng on a large scale. Herein, we demonstrate how to optimize ginseng production through cultivation, and how to enhance the concentrations of specific ginsenosides through fermentation. In the study, we also evaluated the ability of fermented cultured wild ginseng root extract (HLJG0701-β) to inhibit acetylcholinesterase (AChE), as well as its neuroprotective effects and antioxidant activity. In invitro tests, HLJG0701-β inhibited AChE activity and exerted neuroprotective and antioxidant effects (showing increased catalyst activity but decreased reactive oxygen species concentration). In invivo tests, after HLJG0701-β was orally administered at doses of 0, 125, 250, and 500 mg/kg in an animal model of memory impairment, behavioral evaluation (Morris water maze test and Y-maze task test) was performed. The levels of AChE, acetylcholine (ACh), blood catalase (CAT), and malondialdehyde (MDA) in brain tissues were measured. The results showed that HLJG0701-β produced the best results at a dose of 250 mg/kg or more. The neuroprotective mechanism of HLJG0701-β was determined to involve the inhibition of AChE activity and a decrease in oxidative stress. In summary, both invitro and invivo tests confirmed that HJG0701-β administration can lead to memory improvement.

An Efficient Synthesis of Ginsenoside Rg5 via Conversion of PPD Type Saponins: Unusual Application of 4A Molecular Sieves

Ginsenoside Rg5 is a rare secondary ginsenoside with good pharmacological activity. However, preparation of Rg5 is time consuming, gives a low yield and has poor selectivity and efficiency. Therefore, the current study describes an efficient method of preparing ginsenoside Rg5 through conversion of Protopanaxadiol (PPD) type saponins in the presence of a molecular sieve and hydrochloric acid. The PPD type saponins were transformed on the surface of a molecular sieve to obtain ginsenoside Rg5 and most of the generated secondary ginsenoside was dissociates into the reaction solution, avoiding further decomposition. In addition, the optimal experimental conditions were identified to be as follows; 0.5 ml of absolute ethanol, 0.2 mol/L of hydrochloric acid, 12.5 mg of a 4A molecular sieve, a reaction time of 2.5 hours and a reaction temperature of 70 ℃. Under these experimental conditions, yields of upto 63.2% were obtained for ginsenoside Rg5. Moreover, the hydrochloric acid-catalyzed preparation of ginsenoside Rg5 effectively inhibited its decomposition in the presence of a molecular sieve. The method is therefore suitable for laboratory and industrial production with the advantages of large-scale preparation and high-yield.

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.

Ginsenoside Rg5/Rk1 ameliorated sleep via regulating the GABAergic/serotoninergic signaling pathway in a rodent model

As the most common sleep disorder, insomnia seriously affects people's everyday lives. Phytochemicals have been shown to have excellent sleep-promoting effects. Therefore, this study was designed to investigate whether Rg5 and Rk1 extracted from ginseng had sleep-promoting effects and to explore their potential mechanisms. The results showed that Rg5 and Rk1 could significantly lessen the locomotor activity of mice and promote the sleep quality index, including increasing the amount of sleep in a pentobarbital sodium experiment with a threshold dose. In parallel, Rg5 and Rk1 could significantly shorten the sleep latency of mice and prolong the sleep time of mice. Furthermore, Rg5 and Rk1 augmented the GABA/Glu ratio, up-regulating the expression of the GABAA receptor and the GABAB receptor, whereas the GABAA receptor antagonist picrotoxin could antagonize the sleep quality of Rg5/Rk1. In addition, 5-HTP, the precursor of 5-HT, could enhance the sleep effect of Rg5 and Rk1 in mice, and both Rg5 and Rk1 could up-regulate the expression of 5-HT1A. These results were also confirmed by the detection of GABA and 5-HT in mouse cecum content. In conclusion, ginsenoside Rg5/Rk1 can exert sedative and hypnotic effects by affecting the GABA nervous system and the serotonin nervous system.

Natural compounds against doxorubicin-induced cardiotoxicity: A review on the involvement of Nrf2/ARE signaling pathway

Cardiotoxicity is the main concern for long-term use of the doxorubicin (DOX). Reactive oxygen species (ROS) generation leads to oxidative stress that significantly contributes to the cardiac damage induced by DOX. The nuclear factor erythroid 2-related factor (Nrf2) acts as a protective player against DOX-induced myocardial oxidative stress. Several natural compounds (NCs) with anti-oxidative effects, were examined to suppress DOX cardiotoxicity such as asiatic acid, α-linolenic acid, apigenin, baicalein, β-lapachone, curdione, dioscin, ferulic acid, Ganoderma lucidum polysaccharides, genistein, ginsenoside Rg3, indole-3-carbinol, naringenin-7-O-glucoside, neferine, p-coumaric acid, pristimerin, punicalagin, quercetin, sulforaphane, and tanshinone IIA. The present article, reviews NCs that showed protective effects against DOX-induced cardiac injury through induction of Nrf2 signaling pathway.

Ginsenoside Rk1 alleviates LPS-induced depression-like behavior in mice by promoting BDNF and suppressing the neuroinflammatory response

Ginsenoside Rk1, a saponin component produced by heat-processed ginseng, possesses anti-inflammatory and antitumor activities. The aim of our study was to explore the effects of Rk1 on Lipopolysaccharide (LPS)-induced depression-like behavior in mice and to observe its effects on oxidative stress, the inflammatory response and brain-derived neurotrophic factor (BDNF) - tropomyosin-related kinase B (TrkB) signaling. After mice were pretreated with Rk1 (5, 10, and 20 mg/kg), the immobility time in both the forced swimming test (FST) and the tail suspension test (TST) was reduced, suggesting that Rk1 effectively improved depression-like symptoms. Rk1 (10 and 20 mg/kg) and Fluoxetine (Flu, 20 mg/kg) increased the activity of the antioxidant enzyme SOD in the brain and protected against lipid peroxidation. Different concentrations of Rk1 (10 and 20 mg/kg) and Flu significantly decreased the levels of tumor necrosis factor (TNF)-α and interleukin (IL)-1 in serum, while Rk1 (5, 10, and 20 mg/kg) and Flu reduced the concentrations of IL-6 in a dose-dependent manner. Western blot analysis showed that the administration of Rk1 (20 mg/kg) and Flu significantly downregulated the level of Sirt1 and that Rk1 (5, 10, and 20 mg/kg) and Flu inhibited the p-NF-κb/NF-κb and p-IκB-α/IκB-α ratios, which indicated that the neuroprotective effect of Rk1 may be related to the suppression of inflammation. In addition 5, 10 and 20 mg/kg Rk1 significantly attenuated the LPS-induced decreases in BDNF and TrkB. These results indicated that Rk1 acts as an antidepressant through its antioxidant activity, the inhibition of neuroinflammation, and the positive regulation of the BDNF-TrkB pathway. This study may help develop active ginsenoside-based compounds for neurodegenerative diseases.

Protective effects of Hydrocotyle umbellata var. bonariensis Lam. (Araliaceae) on memory in sleep-impaired female mice

ETHNOPHARMACOLOGICAL RELEVANCE

Hydrocotyle umbellata var.bonariensis Lam. (Hb), popularly known in Brazil as acariçoba and outside Brazil Hb by a number of names including marsh-pennywort, and many-flower, has traditionally been used in Ayurvedic medicine in the retardation of aging (Rasayana effect).

AIM OF THE STUDY

The present study evaluated the effect of Hb treatment before and during paradoxical sleep deprivation (PSD) and sleep restriction (SR) on learning, memory, and acetylcholinesterase (AChE) brain activity.

MATERIAL AND METHODS

Adult Swiss nulliparous female mice were randomly distributed among the experimental groups. The treated groups received the aqueous solution of Hb leaves orally at concentrations of 500 and 1.000 mg/kg. PSD and SR were induced by the multiple platform method, in which the animals remained for 3-days in PSD or 15-days in SR for 22 h per day. The collection of the vaginal epithelium occurred daily to determine the estrous cycle. Body mass gain was determined. The animals were submitted to the passive avoidance test and were then euthanized for the collection of brain tissue and the determination of cerebral cholinesterase activity.

RESULTS

The aqueous solution of Hb was associated with a significant reduction in cholinesterase activity at both doses in the SR model, and at the dose of 1.000 mg/kg in the PSD model. Regarding the learning and memory test, the PSD group treated with 1.000 mg/kg presented significant improvement, whereas in the SR experiment none of the treated-groups showed any improvement in learning and memory. In the analysis of SR/PSD interference and/or Hb treatment on the estrous cycle, it was possible to observe that the treatment acted as a protector in the SR group, maintaining a normal cycle.

CONCLUSIONS

The analyses showed that Hb was safe to use during periods of SR or PSD, acting as an adaptogen for these situations, in addition to being able to reduce cholinesterase activity, which suggests its neuroprotective action. In relation to the estrous cycle, Hb can act as a protector in SR situations.

Ginsenosides Rg5 and Rk1 Enriched Cultured Wild Ginseng Root Extract Bioconversion of Pediococcus pentosaceus HLJG0702: Effect on Scopolamine-Induced Memory Dysfunction in Mice

Wild ginseng is known to contain additional physiologically and pharmacologically active substances than common ginseng. The utilization of this herb can be maximized by altering its composition via tissue culture generating adventitious roots. We enriched the content of specific ginsenosides and investigated their role in ameliorating memory impairment. Cultured wild ginseng root was subjected to extraction, steaming, and fermentation using Pediococcus pentosaceus HLJG0702 to enhance the levels of ginsenosides Rg5 /Rk1. The analysis of product, HLJG0701, confirmed target ginsenosides. We analyzed the inhibitory effect of ginsenoside Rg5/Rk1, HLJG0701 and the raw material on acetylcholinesterase. Further, we performed Morris water maze, Y-maze, and passive avoidance tasks with mice exhibiting memory deficit induced by scopolamine, and we analyzed the concentrations of acetylcholinesterase and acetylcholine in their brains. Studies showed that the levels of ginsenosides Rg5 /Rk1, not found in the raw material, were enhanced in HLJG0701. Ginsenosides and HLJG0701 significantly inhibited acetylcholinesterase unlike the raw material. In all behavioral tasks, HLJG0701 showed memory improvement. It reduced acetylcholinesterase, whereas, it preserved acetylcholine in brain. In conclusion, cultured wild ginseng root extract fermented by P. pentosaceus HLJG0702 contains the distinctive ginsenosides Rg5/Rk1, which may ameliorate memory impairment via inhibition of acetylcholinesterase resulting in increased acetylcholine levels in the brain.

Ginsenoside Rk1 is a novel inhibitor of NMDA receptors in cultured rat hippocampal neurons

Background

Ginsenoside Rk1, a saponin component isolated from heat-processed Panax ginseng Meyer, has been implicated in the regulation of antitumor and anti-inflammatory activities. Although our previous studies have demonstrated that ginsenoside Rg3 significantly attenuated the activation of NMDA receptors (NMDARs) in hippocampal neurons, the effects of ginsenosides Rg5 and Rk1, which are derived from heat-mediated dehydration of ginsenoside Rg3, on neuronal NMDARs have not yet been elucidated.

Methods

We examined the regulation of NMDARs by ginsenosides Rg5 and Rk1 in cultured rat hippocampal neurons using fura-2–based calcium imaging and whole-cell patch-clamp recordings.

Results

The results from our investigation showed that ginsenosides Rg3 and Rg5 inhibited NMDARs with similar potencies. However, ginsenoside Rk1 inhibited NMDARs most effectively among the five compounds (Rg3, Rg5, Rk1, Rg5/Rk1 mixture, and protopanaxadiol) tested in cultured hippocampal neurons. Its inhibition is independent of the NMDA- and glycine-binding sites, and its action seems to involve in an interaction with the polyamine-binding site of the NMDAR channel complex.

Conclusion

Taken together, our results suggest that ginsenoside Rk1 might be a novel component contributable to the development of ginseng-based therapeutic treatments for neurodegenerative diseases.

Ginsenoside Rk1 Induces Apoptosis in Neuroblastoma Cells Through Loss of Mitochondrial Membrane Potential and Activation of Caspases

Neuroblastoma (NB) is the most common childhood cancer, with a very poor prognosis. More than 60% of children with NB die within five years; therefore, a more effective therapy for NB is required. Although ginsenoside has been shown to significantly inhibit the growth of various cancers, the effect of ginsenoside Rk1 on neuroblastoma has not been known yet. Hence, we examined the anticancer effects of highly pure Rk1 on neuroblastoma cell lines. The apoptotic effects of Rk1 on neuroblastoma cells were examined using cell viability assay, flow cytometry and cell staining assay, and the change in gene expression levels were analysed using RT-PCR, western blots, and immunohistochemistry. The metastatic effect of Rk1 was monitored by wound healing assay, invasion and migration with Matrigels. Rk1 inhibited neuroblastoma cell viability dose-dependently. Rk1-induced apoptosis was investigated through nuclear condensation and mitochondrial membrane potential loss, and it showed that Rk1 can induce cell cycle arrest at the G0/G1 phase but also inhibit the metastatic ability of neuroblastoma cells. Moreover, Rk1 (30 mg/kg) injections markedly inhibited xenograft tumor growth. These findings demonstrate that Rk1 might be valuable in the development of anti-cancer agents for neuroblastoma treatment.

Traditional Chinese herbal medicine for vascular dementia

BACKGROUND

Traditional Chinese herbal medicine (TCHM) is widely used for treating vascular dementia (VaD) in China. Recent studies of a number of TCHMs have demonstrated in vitro biological activity and therapeutic effects in animals, but the published clinical evidence has not been systematically appraised.

OBJECTIVES

To evaluate the efficacy and safety of TCHMs listed in either the Chinese Pharmacopoeia (CP) or the Chinese National Essential Drug List (NEDL) that are used to treat VaD. A secondary aim was to identify promising TCHMs for further clinical research.

SEARCH METHODS

We searched ALOIS, the Cochrane Dementia and Cognitive Improvement Group's Specialised Register (on 14 March 2018) and also several Chinese biomedical databases: the Chinese Biological Medicine Database (January 1979 to May 2015), Wanfang database (January 1998 to May 2015), Chongqing VIP Information Co. Ltd or Weipu (January 1998 to May 2015) and the Chinese National Knowledge Infrastructure (January 1979 to May 2015).

SELECTION CRITERIA

We included randomised controlled trials (RCTs) of TCHMs compared to placebo, to Western medicine (WM) or to routine therapy for VaD risk factors. Eligible participants were men and women aged 18 years and above, diagnosed with VaD by any of the following four criteria: (1) Diagnostic and Statistical Manual of Mental Disorders (DSM) versions III, III-R, IV, IV-TR; (2) National Institute of Neurological Disorders and Stroke (NINDS-AIREN); (3) International Classification of Diseases 9 or 10; (4) the Hachinski or the Modified Hachinski Ischaemic Score. We required the use of an imaging technique to differentiate VaD from other dementias. We excluded (1) trials with participants diagnosed with mixed dementia or those that did not use an imaging technique to ascertain VaD; (2) trials of NEDL-listed Gingko biloba or Huperzine A as experimental interventions, to avoid duplication of existing Cochrane Reviews; (3) trials using acupuncture alone as the experimental intervention; (4) trials using another CP- or NEDL-listed TCHM (except for Huperzine A and Gingko which are popular in Western practice) as the control intervention; and (5) trials using purely non-pharmacological interventions as the control intervention unless explicitly described as 'routine therapy for VaD risk factors'.

DATA COLLECTION AND ANALYSIS

We assessed the risks of bias using the Cochrane 'Risk of bias' tool and adapted the Outcome Reporting Bias in Trials (ORBIT) classification system for outcome reporting bias. We assessed TCHM effects on five clinically important outcomes: cognition, global performance, safety, activities of daily living and behaviour and summarised the effects using mean differences for continuous outcomes and risk ratios or risk differences for binary outcomes. We stratified the studies into those that estimated the TCHM versus 'no treatment' effect and those that estimated the TCHM versus the WM effect, with further stratification by the specific TCHM tested or by one of the four modes of action. We pooled using a random-effects model. Due to substantial clinical and design heterogeneity, we did not estimate an 'overall TCHM effect'.

MAIN RESULTS

We only found studies (47 studies, 3581 participants) for 18 of the 29 eligible TCHMs as defined by our inclusion criteria. All were superiority trials conducted in China between 1997 and 2013, with most employing a two-arm parallel design with sample sizes ranging from 26 to 240 and a median treatment duration of 12 weeks (range: 2 to 24 weeks).We found that reporting and trial methodology were generally poor; in particular, there was a lack of information on randomisation, an absence of blinding of participants and outcome assessors and incomplete reporting of adverse events (AEs). None of the 30 trials published from 2007 onwards adopted the CONSORT recommendations for reporting RCTs of herbal interventions.We found seven TCHMs which each had potentially large benefits in studies estimating the TCHM versus 'no treatment' effect and in studies estimating the TCHM versus the WM effect. Two TCHMs (NaoXinTong and TongXinLuo) were common to both groups. Three of these TCHMs - Nao XinTong, NaoMaiTai and TongXinLuo - had the strongest evidence to justify further research. Two TCHMs (NaoMaiTai and TongXinLuo) had a 5% or more increased risk of AEs compared to the 'no Treatment' control, but the quality of this evidence was poor.

AUTHORS' CONCLUSIONS

We found moderate- to very low-quality evidence of benefit and harm of TCHMs for VaD. Methodological inadequacies need to be addressed by better conducted and reported trials. We identified NaoMaiTai, NaoXinTong and TongXinLuo as warranting special research priority.

Ginsenoside Rk1 bioactivity: a systematic review

Ginsenoside Rk1 (G-Rk1) is a unique component created by processing the ginseng plant (mainly Sung Ginseng (SG)) at high temperatures. The aim of our study was to systematically review the pharmacological effects of G-Rk1. We utilized and manually searched eight databases to select in vivo and in vitro original studies that provided information about biological, pharmaceutical effects of G-Rk1 and were published up to July 2017 with no restriction on language or study design. Out of the 156 papers identified, we retrieved 28 eligible papers in the first skimming phase of research. Several articles largely described the G-Rk1 anti-cancer activity investigating "cell viability", "cell proliferation inhibition", "apoptotic activity", and "effects of G-Rk1 on G1 phase and autophagy in tumor cells" either alone or in combination with G-Rg5. Others proved that it has antiplatelet aggregation activities, anti-inflammatory effects, anti-insulin resistance, nephroprotective effect, antimicrobial effect, cognitive function enhancement, lipid accumulation reduction and prevents osteoporosis. In conclusion, G-Rk1 has a significant anti-tumor effect on liver cancer, melanoma, lung cancer, cervical cancer, colon cancer, pancreatic cancer, gastric cancer, and breast adenocarcinoma against in vitro cell lines. In vivo experiments are further warranted to confirm these effects.

Chronic dietary ginseng extract administration ameliorates antioxidant and cholinergic systems in the brains of aged mice

Background

Black ginseng has a more potent biological activity than non-steamed ginseng. We investigated the effects of long-term intake of dietary black ginseng extract (BG) on antioxidant activity in aged mice. We also compared the effects of BG on cognitive deficits with those of white ginseng extract (WG) and red ginseng extract (RG).

Methods

Ten-month-old mice were fed an AIN-93G-based diet containing 10 g/kg (low dose, L) or 30 g/kg (high dose, H) WG powder, RG powder, or BG powder for 24 wk. We measured serum lipids, the activities of antioxidant enzymes, and malondialdehyde levels. Additionally, the protein expression levels of choline acetyltransferase and vesicular acetylcholine transporter, which are presynaptic cholinergic markers in the cortex and hippocampus of the brain, were measured by western blotting.

Results

Triglyceride levels were reduced in all the extract-treated mice, except those in the LBG group. High-density lipoprotein cholesterol levels in the HBG group were higher than those in the control group. Total cholesterol levels were reduced in the LBG group. Additionally, glucose levels in the HBG group were significantly reduced by 41.2%. There were lower levels of malondialdehyde in the LBG group than in the control group. Furthermore, glutathione reductase activity increased in the HWG group and the HRG group. The protein expression levels of choline acetyltransferase and vesicular acetylcholine transporter significantly increased in all the ginseng-treated groups.

Conclusion

The results suggest that supplementation with the tested ginseng extracts may suppress the cognitive decline associated with aging, via regulation of the cholinergic and antioxidant defense systems.

Involvement of serotonergic, noradrenergic and dopaminergic systems in the antidepressant-like effect of ginsenoside Rb1, a major active ingredient of Panax ginseng C.A. Meyer

ETHNOPHARMACOLOGY RELEVANCE

Ginsenoside Rb1, a 20 (S)-protopanaxadiol, is a major active ingredient of Panax ginseng C.A. Meyer, which as the King of Chinese herbs, has been wildly used for the treatment of central nervous system diseases. Previous studies have shown that 20 (S)-protopanaxadiol possesses a novel antidepressant-like effect in the treatment of depression, whereas ginsenoside Rb1 in depression has been rarely reported.

AIM OF THE REVIEW

The present study was to investigate the antidepressant-like effect of ginsenoside Rb1 and its relevant mechanisms.

MATERIALS AND METHODS

The whole experiment was divided into two parts: one part we examined the antidepressant-like effect of ginsenoside Rb1 with open-field test (OFT), tail suspension test (TST), forced swim test (FST), 5-HTP induced head-twitch and reserpine response in mice, another part we used chronic unpredicted mild stress (CUMS) model to further explore the antidepressant-like effect of ginsenoside Rb1 with caffeine, fluoxetine and p-Chlorophenylalanine (PCPA) in rats. Furthermore, the levels of monoamine neurotransmitters of NE, 5-HT, DA and their metabolites 5-HIAA, DOPAC, HVA were all measured by ELISA kits after the CUMS protocol.

RESULTS

Our data indicated that 7 days treatment with ginsenoside Rb1 (4, 8, 10mg/kg, p.o.) significantly decreased immobility time in the FST and TST in mice, and played important roles in mice which were induced by 5-HTP (200mg/kg, i.p.) and reserpine (4mg/kg, i.p.). On the basis of CUMS model, 21 days treatment with ginsenoside Rb1 not only had effective interactions with caffeine (5mg/kg, i.p.), fluoxetine (1mg/kg, i.p.) and PCPA (100mg/kg, i.p.), but also significantly up-regulated the 5-HT, 5-HIAA, NE and DA levels in CUMS rats' brain, whereas HVA and DOPAC had no significant difference. Moreover, there was no alteration in spontaneous locomotion in any experimental group.

CONCLUSIONS

These results suggest that ginsenoside Rb1 exhibits significant antidepressant-like effect in behavioral tests, chronic animal model and drug interactions, its mechanisms mainly mediated by central neurotransmitters of serotonergic, noradrenergic and dopaminergic systems.

Ginsenoside Rg5 Ameliorates Cisplatin-Induced Nephrotoxicity in Mice through Inhibition of Inflammation, Oxidative Stress, and Apoptosis

Although cisplatin is an effective anti-cancer agent that is widely used for treating various types of malignant solid tumors, the nephrotoxicity induced by cisplatin severely limits its clinical application. The present study was designed to explore the potential protective effect of ginsenoside Rg5, a rare ginsenoside generated during steaming ginseng, on cisplatin-induced nephrotoxicity in a mouse experimental model. The possible mechanisms underlying this nephroprotective effect were also investigated for the first time. Rg5 was given at doses of 10 and 20 mg/kg for 10 consecutive days. On Day 7, a single nephrotoxic dose of cisplatin (25 mg/kg) was injected to mice. Cisplatin administration resulted in renal dysfunction as evidenced by increase in serum creatinine (CRE) and blood urea nitrogen (BUN) levels. In addition, cisplatin increased the level of malondialdehyde (MDA) and 4-hydroxynonenal (4-HNE), the makers of lipid peroxidation, and depleted glutathione (GSH) content and superoxide dismutase (SOD) activity in renal tissues. These effects were associated with the significantly increased levels of cytochrome P450 E1 (CYP2E1), 4-hydroxynonenal (4-HNE), tumor necrosis factor (TNF)-α, interleukin (IL)-1β, nuclear factor-kappa B (NF-κB) p65, and cyclooxygenase-2 (COX-2) in renal tissues. However, pretreatment with ginsenoside Rg5 significantly attenuated the renal dysfunction, oxidative stress and inflammation response induced by cisplatin. Furthermore, ginsenoside Rg5 supplementation inhibited activation of apoptotic pathways through increasing Bcl-2 and decreasing Bax expression levels. Histopathological examination further confirmed the nephroprotective effect of Rg5. Collectively, these results clearly suggest that Rg5-mediated alleviation of cisplatin-induced nephrotoxicity may be related to its anti-oxidant, anti-apoptotic and anti-inflammatory effects.

A Role of Ginseng and Its Constituents in the Treatment of Central Nervous System Disorders

Ginseng, a perennial plant belonging to the Panax genus of the Araliaceae family, has been used in China, Korea, and Japan as a traditional herbal medicine for thousands of years. Ginseng is recorded to have exhibited a wide variety of beneficial pharmacological effects and has become a popular and worldwide known health supplement and drug. The protective effects of ginseng on central nervous system are discussed in this review. Ginseng species and ginsenosides and their intestinal metabolism and bioavailability are concisely introduced. The molecular mechanisms of the effects of ginseng on central nervous system, mainly focused on the neuroprotection properties of ginseng, memory, and learning enhanced properties, and the effects on neurodegenerative disorders are presented. Thus, ginseng and its constituents are of potential merits in the treatment of cerebral disorders.

Heat-processed ginseng enhances the cognitive function in patients with moderately severe Alzheimer's disease

OBJECTIVES

Ginseng has been reported to improve cognitive function in animals and in healthy and cognitively impaired individuals. In this study, we investigated the efficacy of a heat-processed form of ginseng that contains more potent ginsenosides than raw ginseng in the treatment of cognitive impairment in patients with moderately severe Alzheimer's disease (AD).

METHODS

Forty patients with AD were randomized into one of three different dose groups or the control group as follows: 1.5 g/day (n = 10), 3 g/day (n = 10), and 4.5 g/day (n = 10) groups, or control (n = 10). The Alzheimer's Disease Assessment Scale (ADAS) and Mini-Mental State Examination (MMSE) were used to assess cognitive function for 24 weeks.

RESULTS

The treatment groups showed significant improvement on the MMSE and ADAS. Patients with higher dose group (4.5 g/day) showed improvements in ADAS cognitive, ADAS non-cognitive, and MMSE score as early as at 12 weeks, which sustained for 24-week follow-up.

DISCUSSION

These results demonstrate the potential efficacy of a heat-processed form of ginseng on cognitive function and behavioral symptoms in patients with moderately severe AD.

Effect of Korean Red Ginseng on Cognitive Function and Quantitative EEG in Patients with Alzheimer's Disease: A Preliminary Study

BACKGROUND

Korean red ginseng (KRG) has a nootropic effect. This study assessed the efficacy of KRG on cognitive function and quantitative electroencephalography (EEG) in patients with Alzheimer's disease (AD).

METHODS

Fourteen patients with AD (mean age, 74.93 years; 11 women and 3 men) were recruited and treated with KRG (4.5 g per day) for 12 weeks. Cognitive function was assessed by the Korean Mini-Mental State Examination (K-MMSE) and the Frontal Assessment Battery (FAB). EEG performed before and after treatment were analyzed with quantitative spectral analysis.

RESULTS

The FAB score improved significantly after 12 weeks of treatment. In the relative power spectrum analysis performed according to responsiveness, alpha power increased significantly in the right temporal area of the responders. The increments of relative alpha power in the right temporal, parietal, and occipital areas were significantly higher in the responders than the nonresponders.

CONCLUSIONS

This study indicates the efficacy of KRG on frontal lobe function in AD, related to increasing relative alpha power.

Neuroprotective effects of ginseng protein on PI3K/Akt signaling pathway in the hippocampus of D-galactose/AlCl3 inducing rats model of Alzheimer's disease

ETHNOPHARMACOLOGICAL RELEVANCE

Alzheimer disease (AD) is a progressive neurodegenerative disease, with progressive memory loss, cognitive deterioration, and behavioral disorders. Ginseng (Panax ginseng C.A. Meyer) is widely used in China to treat various kinds of nervous system disorders. The study aimed to explore the therapeutic effect of ginseng protein (GP) on Alzheimer's disease and its correlation with the PI3K/Akt signaling pathway to understand the mechanism underlying the neuroprotective effect of ginseng.

MATERIAL AND METHODS

The AD rat model was established by intraperitoneally injecting D-galactose [60mg/(kgd)] followed by intragastrically administering AlCl3 [40mg/(kgd)] for 90 days. From day 60, the GP groups were intragastrically administered with GP 0.05 or 0.1g/kg twice daily for 30 days. The ethology of rats was tested by Morris water maze test. The content of Aβ1-42 and p-tau in the hippocampus of rats was detected by enzyme-linked immunosorbent assay. The expression of mRNAs and proteins of PI3K, Akt, phosphorylated Akt (p-Akt), Bcl-2, and Bax in the hippocampus was detected by real-time quantitative reverse transcription polymerase chain reaction and Western blot assay.

RESULTS

GP was found to significantly improve the memory ability of AD rats and prolong the times of crossing the platform and the percentage of residence time in the original platform quadrant of spatial probe test. GP also reduced the content of Aβ1-42 and p-tau and improved the mRNA and protein expression of PI3K, p-Akt/Akt, and Bcl-2/Bax in the hippocampus.

CONCLUSIONS

GP could improve the memory ability and reduce the content of Aβ1-42 and p-tau in AD rats. The anti-AD effects of GP were in part mediated by PI3K/Akt signaling pathway activation.

Metabolite profiles of ginsenosides Rk1 and Rg5 in zebrafish using ultraperformance liquid chromatography/quadrupole-time-of-flight MS

BACKGROUND

In the present study, metabolite profiles of ginsenosides Rk1 and Rg5 from red ginseng or red notoginseng in zebrafish were qualitatively analyzed with ultraperformance liquid chromatography/quadrupole-time-of-flight MS, and the possible metabolic were pathways proposed.

METHODS

After exposing to zebrafish for 24 h, we determined the metabolites of ginsenosides Rk1 and Rg5. The chromatography was accomplished on UPLC BEH C18 column using a binary gradient elution of 0.1% formic acetonitrile-0.1% formic acid water. The quasimolecular ions of compounds were analyzed in the negative mode. With reference to quasimolecular ions and MS2 spectra, by comparing with reference standards and matching the empirical molecular formula with that of known published compounds, and then the potential structures of metabolites of ginsenosides Rk1 and Rg5 were acquired.

RESULTS

Four and seven metabolites of ginsenoside Rk1 and ginsenoside Rg5, respectively, were identified in zebrafish. The mechanisms involved were further deduced to be desugarization, glucuronidation, sulfation, and dehydroxymethylation pathways. Dehydroxylation and loss of C-17 residue were also metabolic pathways of ginsenoside Rg5 in zebrafish.

CONCLUSION

Loss of glucose at position C-3 and glucuronidation at position C-12 in zebrafish were regarded as the primary physiological processes of ginsenosides Rk1 and Rg5.

Formulation of pea protein for increased satiety and improved foaming properties

Pea protein was successfully encapsulated into a lipophilic carrier through PGSS®. HPT-scCO₂of pea protein has enabled higher foam stability.

American ginseng regulates gene expression to protect against premature ovarian failure in rats

Premature ovarian failure (POF) is defined as lost ovarian functions before the age of 40. Three possible molecular markers (PLA2G4A, miR-29a, and miR-144) have been identified in our previous study by integrated analysis of mRNA and miRNA expression profiles. The present study aimed to evaluate American ginseng root's protective potential against POF by studying transcriptional and protein variations between American ginseng treatments and controls in rats. 4-Vinylcyclohexene diepoxide (VCD) was administered to rats for 14 days to induce POF. Additionally, American ginseng was administered to POF rats for one month, and PLA2G4A, miR-29a, and miR-144 expressions were measured in rat ovaries by qRT-PCR. PLA2G4A protein expression was examined by Western Blot, and PGE₂, LH, FSH, and E2 serum levels were detected by ELISA. PLA2G4A mRNA and protein were downregulated in American ginseng-treated rats, miR-29a and miR-144 levels increased, and PGE₂ serum levels decreased, while LH, FSH, and E2 increased compared to POF induction alone. Analysis of transcriptional and protein variations suggested that American ginseng protects the ovary against POF by regulating prostaglandin biosynthesis, ovulation, and preventing ovarian aging. High hormone levels (PGE₂, FSH, and LH) were reduced, and E2 secretion approached normal levels, leading to improved POF symptoms and abnormal ovulation.

Stimulative effect of ginsenosides Rg5:Rk1 on murine osteoblastic MC3T3-E1 cells

Panax ginseng C.A. Meyer (P. ginseng), hereafter referred to as P. ginseng, is known to exert a wide range of pharmacological effects both in vitro and in vivo; however, few studies have investigated the effects of ginseng on bone metabolism. We therefore investigated the potential antiosteoporotic properties of ginseng on the growth and differentiation of murine MC3T3-E1 cells. Rg5:Rk1 is a mixture of protopanaxadiol-type ginsenosides, isolated from fresh P. ginseng root, via a repetitive steaming and drying process. In this study, we examined the stimulatory effects of Rg5:Rk1 on the differentiation and mineralization of MC3T3-E1 cells. Undifferentiated cells were treated with a range of concentrations of Rg5:Rk1 (1-50 µg/mL), and cell viability was measured with the 3-(4,5-dimethyl-thiazol-2yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. Treatment with Rg5:Rk1 significantly increased cell viability in a dose-dependent manner. To investigate the possible mechanisms by which Rg5:Rk1 affects the early differentiation phase of MC3T3-E1 cells, the cells were treated with Rg5:Rk1 for 14-24 days before assessing the levels of multiple osteoblastic markers. The markers examined included alkaline phosphatase (ALP) activity type I collagen content (Coll-I), calcium deposition (by Alizarin Red S staining), extracellular mRNA expression of bone morphogenetic protein-2 (BMP-2), and the level of Runt-related transcription factor 2 (Runx2). Rg5:Rk1 treatment also increased the activities of proteins associated with osteoblast growth and differentiation in a dose-dependent manner. Overall, we found that the Rg5:Rk1 mixture of ginsenosides improved the osteoblastic function of MC3T3-E1 cells by increasing their proliferative capacity. This improvement is due to the action of Rg5:Rk1 on BMP-2, which is mediated by Runx2-dependent pathways.

Effects of ginseol k-g3, an Rg3-enriched fraction, on scopolamine-induced memory impairment and learning deficit in mice

Background

Although ginsenosides such as Rg1, Rb1 and Rg3 have shown promise as potential nutraceuticals for cognitive impairment, their use has been limited due to high production cost and low potency. In particular, the process of extracting pure Rg3 from ginseng is laborious and expensive.

Methods

We described the methods in preparing ginseol k-g3, an Rg3-enriched fraction, and evaluated its effects on scopolamine-induced memory impairment in mice.

Results

Ginseol k-g3 (25–200 mg/kg) significantly reversed scopolamine-induced cognitive impairment in the passive avoidance, but not in Y-maze testing. Ginseol k-g3 (50 and 200 mg/kg) improved escape latency in training trials and increased swimming times within the target zone of the Morris water maze. The effect of ginseol k-g3 on the water maze task was more potent than that of Rg3 or Red ginseng. Acute or subchronic (6 d) treatment of ginseol k-g3 did not alter normal locomotor activity of mice in an open field. Ginseol k-g3 did not inhibit acetylcholinesterase activity, unlike donezepil, an acetylcholinesterase inhibitor. Rg3 enrichment through the ginseol k-g3 fraction enhanced the efficacy of Rg3 in scopolamine-induced memory impairment in mice as demonstrated in the Morris water maze task.

Conclusion

The effects of ginseol k-g3 in ameliorating scopolamine-induced memory impairment in the passive avoidance and Morris water maze tests indicate its specific influence on reference or long-term memory. The mechanism underlying the reversal of scopolamine-induced amnesia by ginseol k-g3 is not yet known, but is not related to anticholinesterase-like activity.

Traditional Korean East Asian medicines and herbal formulations for cognitive impairment

Hanbang, the Traditional Korean Medicine (TKM), is an inseparable component of Korean culture both within the country, and further afield. Korean traditional herbs have been used medicinally to treat sickness and injury for thousands of years. Oriental medicine reflects our ancestor’s wisdom and experience, and as the elderly population in Korea is rapidly increasing, so is the importance of their health problems. The proportion of the population who are over 65 years of age is expected to increase to 24.3% by 2031. Cognitive impairment is common with increasing age, and efforts are made to retain and restore the cognition ability of the elderly. Herbal materials have been considered for this purpose because of their low adverse effects and their cognitive-enhancing or anti-dementia activities. Herbal materials are reported to contain several active compounds that have effects on cognitive function. Here, we enumerate evidence linking TKMs which have shown benefits in memory improvements. Moreover, we have also listed Korean herbal formulations which have been the subject of scientific reports relating to memory improvement.

Effect of ginsenoside Rg3 on tyrosine hydroxylase and related mechanisms in the forced swimming-induced fatigue rats

ETHNOPHARMACOLOGICAL RELEVANCE

Ginsenoside Rg3 has shown multiple pharmacological activities and been considered as one of the most promising approaches for fatigue treatment. However, little is known about the cellular and molecular mechanisms of Rg3 on anti-fatigue and the effect of Rg3 on dopaminergic system has not been reported yet. The major aim of this study is to investigate the effect of Rg3 on TH expression and the related biochemical parameters, such as PKAα, ERK1/2, Akt and α-synuclein in brain of fatigue rats.

MATERIALS AND METHODS

Weight-loaded forced swimming was performed to establish an animal model of fatigue. Rg3 (10mg/kg, 50mg/kg and 100mg/kg) was intragastrically administrated before swimming. The effect of Rg3 on the expression and phosphorylation of TH and TH-related proteins in fatigue rats or in SH-SY5Y cells was assessed with western blotting. HPLC was used to examine the level of DA and DOPAC in the fatigue rats tissues.

RESULTS

TH and phosphorylated TH were decreased in different brain regions of which ventral midbrain were less affected in weight-loaded forced swimming rats. Pretreatment with Rg3 significantly suppressed fatigue-induced decrease expression of TH and TH phosphorylation. Also treatment with Rg3 reversed the decrease expression of PKAα as well as the phosphorylation of ERK1/2 and Akt which were induced by weight-loaded forced swimming. Moreover, weight-loaded swimming could induce the increase expression of α-synuclein in hippocampus and midbrain, while suppressed α-synuclein expression in striatum and prefrontal cortex. Furthermore, Rg3 could induce the increase of TH expression and phosphorylation which was accompanied with elevated expression and phosphorylation of related kinase proteins in vitro, while the inhibitors of kinase proteins could suppress these effects of Rg3. In addition, HPLC results showed that Rg3 could reverse the weight-loaded swimming-induced increase of DOPAC/DA ratio.

CONCLUSION

Our data suggest that fatigue can induce the decrease of DA which might partially result from the change of TH expression and phosphorylation, and Rg3 can reverse these fatigue-induced changes. The underling mechanisms may include the activity changes of PKAα, ERK1/2, Akt and α-synuclein.

Actoprotective effect of ginseng: improving mental and physical performance

Actoprotectors are preparations that increase the mental performance and enhance body stability against physical loads without increasing oxygen consumption. Actoprotectors are regarded as a subclass of adaptogens that hold a significant capacity to increase physical performance. The focus of this article is studying adaptogen herbs of genus Panax (P. ginseng in particular) and their capabilities as actoprotectors. Some animal experiments and human studies about actoprotective properties of genus Panax attest that P. ginseng (administered as an extract) significantly increased the physical and intellectual work capacities, and the data provided suggests that ginseng is a natural source of actoprotectors. Preparations of ginseng can be regarded as potential actoprotectors which give way to further research of its influence on physical and mental work capacity, endurance and restoration after exhaustive physical loads while compared with reference actoprotectors.

Ginsenosides Rg5 and Rh3 protect scopolamine-induced memory deficits in mice

ETHNOPHARMACOLOGICAL RELEVANCE

Panax ginseng (family Araliaceae) is traditionally used as a remedy for cancer, inflammation, stress and aging.

AIM OF STUDY

To explore whether ginsenosides Rg5 and Rh3, the main constituents of heat-processed ginseng (the root of Panax ginseng), could protect memory deficit.

MATERIALS AND METHODS

We isolated ginsenosides Rh3 and Rg5 from heated-processed ginseng treated with and without human feces, respectively. Then we investigated their protective effects on memory impairment using the passive avoidance, Y-maze and Morris water maze tasks in mice. Memory deficit was induced in mice by the intraperitoneal injection of scopolamine.

RESULTS

Ginsenosides Rg5 or Rh3 increased the latency time reduced by scopolamine in passive avoidance test. Treatment with ginsenoside Rg5 or Rh3 significantly reversed the lowered spontaneous alteration induced by scopolamine in Y-maze task. Ginsenoisde Rg5 or Rh3 (10 mg/kg) significantly shortened the escape latencies prolonged by treatment with scopolamine on the last day of training trial sessions in Morris water maze task. Furthermore, ginsenosides Rg5 and Rh3 inhibited acetylcholinesterase activity in a dose-dependent manner, with IC50 values of 18.4 and 10.2 μM, respectively. The inhibitory potency of ginsenoside Rh3 is comparable with that of donepezil (IC50=9.9 μM). These ginsenosides also reversed hippocampal brain-derived neurotrophic factor (BDNF) expression and cAMP response element-binding protein (CREB) phosphorylation reduced by scopolamine. Of them, ginsenoside Rh3 more potently protected memory deficit.

CONCLUSIONS

Ginsenoside Rg5 and its metabolite ginsenoside Rh3 may protect memory deficit by inhibiting AChE activity and increasing BDNF expression and CREB activation.

Chronic administration of anti-stroke herbal medicine TongLuoJiuNao reduces amyloidogenic processing of amyloid precursor protein in a mouse model of Alzheimer's disease

Composed of Ginsenoside Rg1 and Geniposide, the herbal medicine TongLuoJiuNao (TLJN) injection liquid has anti-inflammatory properties and can improve learning and memory in mice. Recently, TLJN has been used to treat the patients with cerebral ischemic stroke and vascular dementia, which significantly increase the risk of developing Alzheimer’s disease (AD) in the early human beings. Although beneficial effects of TLJN have been reported in the vascular-associated brain disorders, the roles of TLJN in AD brains are still not clear. In this study, we chronically administered TLJN in amyloid precursor protein (APP) Swedish mutant transgenic mice (APP23) from 6 months old of age, which is at the onset of Aβ plaques, to 12 months old. We found that TLJN significantly decreased Aβ production and deposition in the brain of APP23 mice. Furthermore, we observed that TLJN down-regulated the levels and activity of β-secretase 1 (BACE1) protein as well as the expression levels of γ-secretase complex components: PS1, nicastrin and anterior pharynx-defective 1 (APH1) but not presenilin enhancer 2 (PEN2). The results suggest an inhibitory effect of TLJN on amyloidogenic APP processing by down-regulating the cleavage enzymes BACE1 and γ-secretase.

The potent effects of ginseng root extract and memantine on cognitive dysfunction in male albino rats

The study determined the maximum intraperitoneal (ip) scopolamine dose inducing memory impairment in rats (2 mg/kg) compared to 0.5 or 1 mg/kg dose. The effect reflected by significant increase from normal in the latency time required for rats to find the hidden platform in water maze task and acetylcholinesterase (AChE) activities in cortex, hippocampus and striatum. The dose-related histopathological effect via the hemorrhage, vacuolation and gliosis in cortex and hippocampus is assessed. Then the study investigated the potency of Panax ginseng root extract on scopolamine cognitive dysfunction rat model compared to memantine hydrochloride as reference Food and Drug Administration approved. Ginseng extract was administered at dose 100 or 200 mg/kg/day and memantine at 20 mg/kg/day orally for 2 weeks. All treatments showed improvement in the water maze task, however, ginseng (200 mg/kg) group acquired the advantage without statistical difference control. Scopolamine (2 mg/kg ip) group showed significant increase in AChE reactivity and glutamate level and reduced monoamines (norepinephrine, dopamine and serotonin) and γ-aminobutyric acid contents in cortex, hippocampus and striatum. Ginseng extract in a dose-dependent manner appears effective as memantine and can improve memory impairment through the retrieved homeostasis via neurotransmitter levels and AChE activities in rat brain areas with partial effect on the histological feature of the brain tissue.

Neuroprotection and Enhancement of Spatial Memory by Herbal Mixture HT008-1 in Rat Global Brain Ischemia Model

To investigate whether HT008-1, a prescription used in traditional Korean medicine to treat mental and physical weakness, has a neuroprotective effect on a rat model of global brain ischemia and an enhancing effect against memory deficit following ischemia. Global brain ischemia was induced for 10 min by using 4-vessel occlusion (4-VO). HT008-1 was orally administered at doses of 30, 100, and 300 mg/kg respectively twice at 0 and 90 min after ischemia. The effect on memory deficit was investigated by using a Y-maze neurobehavioral test 4 days after brain ischemia, and the effect on neuronal damage was measured 7 days after ischemia. The mechanism of action was studied immunohistochemically using an anti-CD11b (OX-42) antibody. The oral administration of HT008-1 at 100 and 300 mg/kg significantly reduced hippocampal neuronal cell death by 49% and 53%, respectively, compared with a vehicle-treated group, and also improved spatial memory function in the Y-maze test. Immunohistochemically, HT008-1 inhibited OX-42 expression in the hippocampus. The effects of HT008-1 were more pronounced than those of its individual herb components. The herbal mixture HT008-1 protects the most vulnerable CA1 pyramidal cells of the hippocampus and enhances spatial memory function against global brain ischemia; an anti-inflammatory effect may be one of the mechanisms of action.

Dose-response effect of black maca (Lepidium meyenii) in mice with memory impairment induced by ethanol

Previous studies have shown that black variety of maca has beneficial effects on learning and memory in experimental animal models. The present study aimed to determine whether the hydroalcoholic extract of black maca (BM) showed a dose-response effect in mice treated with ethanol 20% (EtOH) as a model of memory impairment. Mice were divided in the following groups: control, EtOH, ascorbic acid (AA) and 0.125, 0.25, 0.50 and 1.00 g/kg of BM plus EtOH. All treatments were orally administered for 28 days. Open field test was performed to determine locomotor activity and water Morris maze was done to determine spatial memory. Also, total polyphenol content in the hydroalcoholic extract of BM was determined (0.65 g pyrogallol/100 g). Mice treated with EtOH took more time to find the hidden platform than control during escape acquisition trials; meanwhile, AA and BM reversed the effect of EtOH. In addition, AA and BM ameliorated the deleterious effect of EtOH during the probe trial. Correlation analyses showed that the effect of BM a dose-dependent behavior. Finally, BM improved experimental memory impairment induced by ethanol in a dose-response manner due, in part, to its content of polyphenolic compounds.

Ginsenosides from American ginseng: chemical and pharmacological diversity

Ginseng occupies a prominent position in the list of best-selling natural products in the world. Compared to the long history of use and widespread research on Asian ginseng, the study of American ginseng is relatively limited. In the past decade, some promising advances have been achieved in understanding the chemistry, pharmacology and structure-function relationship of American ginseng. To date, there is no systematic review of American ginseng. In this review, the different structures of the ginsenosides in American ginseng are described, including naturally occurring compounds and those resulting from steaming or biotransformation. Preclinical and clinical studies published in the past decade are also discussed. Highlighted are the chemical and pharmacological diversity and potential structural-activity relationship of ginsenosides. The goal is that this article is a useful reference to chemists and biologists researching American ginseng, and will open the door to agents in drug discovery.

Cell-type-specific regulation of raft-associated Akt signaling

20S-protopanaxadiol (aPPD) is a metabolite of ginseng saponins, which is reported to be pro-apoptotic in some cells but anti-apoptotic in neuronal cells by regulating Akt signaling. Owing to its cholesterol-like structure, we hypothesized that aPPD may regulate Akt signaling by interacting with lipid rafts. Here, we compared Akt signaling in glioblastoma U87MG and neuroblastoma Neuro-2a cells treated with aPPD. aPPD did not change Akt activity in the total plasma membranes of each cell type, but drastically altered the activity of raft-associated Akt. Strikingly, Akt activity was decreased in the rafts of U87MG cells but increased in N2a cells by aPPD through regulating raft-associated dephosphorylation. The bidirectional regulation of raft-associated Akt signaling by aPPD enhanced the chemotoxicity of Paclitaxel or Vinblastine in U87MG cells but attenuated the excitotoxicity of N-methyl--aspartate in N2a cells. Our results demonstrated that the activity of raft-associated but not total membrane Akt determines its cellular functions. Lipid rafts differ in different types of cells, which allows for the possibility of cell-type-specific targeting for which aPPD might prove to be a useful agent.