A Preclinical Systematic Review of Ginsenoside-Rg1 in Experimental Parkinson's Disease

Efficacy of ginsenoside Rg1 on rodent models of depression: A systematic review and meta-analysis

RATIONALE

Depression is a prevalent psychiatric disease, and ginsenoside Rg1 is a bioactive compound extracted from the root of Panax ginseng C.A.Mey. To systematically investigate the effectiveness of Rg1 in rodent models of depression and provide evidence-based references for treating depression.

METHODS

Electronic searches for rodent studies were performed from inception to October 2022, e.g., PUBMED and EMBASE. Data extraction and quality evaluation were performed for the references, and meta-analysis was performed on the selected data using Review Manager 5.3.5. The outcomes were analyzed via a random-effect model and presented as mean difference (MD) with 95% confidence intervals (CIs).

RESULTS

A total of 24 studies and 678 animals were included in this meta-analysis. Rg1 remarkably improved depressive-like symptoms of depressed rodents, including the sucrose preference test (25.08, 95% CI: 20.17-30.00, Z = 10.01, P < 0.00001), forced swimming test (MD = -37.69, 95% CI: (-45.18, -30.2); Z = 9.86, P < 0.00001), and the tail suspension test (MD = -22.93, seconds, 95% CI: (-38.49, -7.37); Z = 2.89, P = 0.004).

CONCLUSIONS

The main antidepressant mechanism of Rg1 was concluded to be the neurotransmitter system, oxidant stress system, and inflammation. Conclusively, this study indicated the possible protective and therapeutic effects of Rg1 for treating depression via multiple mechanisms.

Prevention of colistin-induced neurotoxicity: a narrative review of preclinical data

Polymyxin E or colistin is an effective antibiotic against MDR Gram-negative bacteria. Due to unwanted side effects, the use of this antibiotic has been limited for a long time, but in recent years, the widespread of MDR Gram-negative bacteria infections has led to its reintroduction. Neurotoxicity and nephrotoxicity are the significant dose-limiting adverse effects of colistin. Several agents with anti-inflammatory and antioxidant properties have been used for the prevention of colistin-induced neurotoxicity. This study aims to review the preclinical studies in this field to prepare guidance for future human studies. The data was achieved by searching PubMed, Scopus, and Google Scholar databases. All eligible pre-clinical studies performed on neuroprotective agents against colistin-induced neurotoxicity, which were published up to September 2023, were included. Finally, 16 studies (ten in vitro and eight in vivo) are reviewed. Apoptosis (in 13 studies), inflammatory (in four studies), and oxidative stress (in 14 studies) pathways are the most commonly reported pathways involved in colistin-induced neurotoxicity. The assessed compounds include non-herbal (e.g., ascorbic acid, rapamycin, and minocycline) and herbal (e.g., curcumin, rutin, baicalein, salidroside, and ginsenoside) agents. Besides these compounds, some other measures like transplantation of mitochondria and the use of nerve growth factor and mesenchymal stem cells could be motivating subjects for future research. Based on the data from experimental (in vitro and animal) studies, a combination of colistin with neuroprotective agents could prevent or decrease colistin-induced neurotoxicity. However, well-designed randomized clinical trials and human studies are essential for demonstrating efficacy.

Pharmacokinetics study of ginsenoside Rg1 liposome by pulmonary administration

Ginsenoside Rg1 (Rg1), a monomer saponin component, is one of the components with the highest content in total saponins of Panaxnotoginseng. It had various pharmacological effects. The bioavailability of oral tablets is only 1-20 %, and it is eliminated quickly in the blood. The development of new dosage forms and new routes of administration of ginsenoside Rg1 with sustained release and high bioavailability has become a significant problem to be solved. The Rg1 liposomes study used a thin film dispersion ultrasound method for its preparation. This study focused the pharmacokinetic parameters of ginsenoside Rg1 liposomes in rats through the lung perfusion method. Ginsenoside Rg1 liposomes were round and uniform in shape, the particle size was 2-3 μm, and the encapsulation efficiency of ginsenoside Rg1 liposome was 51.2 %. Results showed that, after pulmonary administration of ginsenoside Rg1, the time of ginsenoside Rg1 detected by Rg1 liposomes was longer than that of Rg1 solution, the relative bioavailability of ginsenoside Rg1 liposome lung administration AUC liposome/AUC solution = 122.67 %. These results provided the scientific theoretical and experimental basis for further development of new dosage forms and new routes of administration of ginsenoside Rg1.

Advancing Kir4.2 Channel Ligand Identification through Collision-Induced Affinity Selection Mass Spectrometry

The inwardly rectifying potassium Kir4.2 channel plays a crucial role in regulating membrane potentials and maintaining potassium homeostasis. Kir4.2 has been implicated in various physiological processes, including insulin secretion, gastric acid regulation, and the pathogenesis of central nervous system diseases. Despite its significance, the number of identified ligands for Kir4.2 remains limited. In this study, we established a method to directly observe ligands avoiding a requirement to observe the high-mass ligand-membrane protein-detergent complexes. This method used collision-induced affinity selection mass spectrometry (CIAS-MS) to identify ligands dissociated from the Kir4.2 channel-detergent complex. The CIAS-MS approach integrated all stages of affinity selection within the mass spectrometer, offering advantages in terms of time efficiency and cost-effectiveness. Additionally, we explored the effect of collisional voltage ramps on the dissociation behavior of the ligand and the ligand at different concentrations, demonstrating dose dependency.

The acceptance of traditional Chinese medicine among patients with Parkinson's disease: A hospital survey

OBJECTIVE

The efficacy of medications for Parkinson's disease (PD) tend to decline over time, which has a serious impact on patients' health and quality of life. To some extent, traditional Chinese medicine (TCM) can resolve the distressing problem of ineffective dopaminergic medication in PD patients. The purpose of this study was to investigate the attitude, acceptance, and independent predictors of TCM in PD patients admitted to the outpatient department of a tertiary hospital.

METHODS

A cross-sectional study of PD patients was conducted in the outpatient department of a large tertiary hospital in Beijing from March 2022 to June 2023. A self-report questionnaire was developed to investigate PD patients' attitudes and acceptance of TCM based on the questionnaire. Multivariate logistic regression analyses were also performed to further clarify the independent predictors influencing patients' adoption of TCM therapy.

RESULTS

A total of 397 patients completed the questionnaire, of which 78.09% were willing to be treated with TCM and 21.91% indicated that they were not willing to use TCM. Multifactorial logistic regression analysis showed that several parameters were correlated with a patient's willingness to include TCM in their therapeutic regime. These included education level of a bachelor's degree (odds ratio [OR) = 8.554; 95% confidence interval [CI]: 4.112-17.794; P < 0.001, vs junior high school education), living in an urban setting (OR = 8.022; 95% CI: 4.577-14.060; P < 0.001, vs rural), having other underlying diseases (OR = 5.126; 95% CI: 3.078-8.537; P < 0.001, vs none), having previously used TCM (OR = 3.083; 95% CI: 1.852-5.134; P < 0.001, vs not used), believing that TCM therapy is safe (OR = 3.530; 95% CI: 1.446-8.616; P = 0.006, vs not thought), believing that TCM therapy is effective (OR = 3.859; 95% CI: 1.482-10.047; P = 0.006, vs not understood), and being willing to discuss ongoing TCM therapy with an attending physician (OR = 62.468; 95% CI: 30.350-128.574; P < 0.001, vs not informed).

CONCLUSION

This study initially investigated the acceptance, attitude, and independent predictors of TCM use among PD patients. To expand the prevalence of TCM use among patients with PD, we recommend to broadening the public outreach for TCM via contemporary means of Internet and broadcast communication, enhancing access to TCM services in rural communities, and strengthening the communication between doctors and patients. Please cite this article as: Wang P, Hong J, Tang ZQ, Gong BZ, Qi XR, Jiang H, Pan B, Chen Q. The acceptance of traditional Chinese medicine among patients with Parkinson's disease: A hospital survey. J Integr Med. 2024; 22(2): 180-187.

Antioxidant and anti-inflammatory properties of ginsenoside Rg1 for hyperglycemia in type 2 diabetes mellitus: systematic reviews and meta-analyses of animal studies

Background: According to existing laboratory data, ginsenoside Rg1 may help cure diabetes and its complications by reducing oxidative stress (OS) and managing inflammation. However, this conclusion lacks reliability and is unclear. As a result, the purpose of this systematic review and meta-analysis was to evaluate the antioxidant and anti-inflammatory effects of ginsenoside Rg1 in the treatment of diabetes and its complications. Methods: We searched for relevant studies published through December 2022, including electronic bibliographic databases such as PubMed, EMBASE, Web of Science, CNKI, and Wanfang. The SYstematic Review Center for Laboratory Animal Experimentation Risk of Bias (SYRCLE RoB) tool was used to conduct a meta-analysis to assess the methodological quality of animal research. The meta-analysis was conducted using RevMan5.4 software, following the Cochrane Handbook for Systematic Reviews of Interventions. This study is registered in the International Systems Review Prospective Registry (PROSPERO) as CRD42023386830. Results: Eighteen eligible studies involving 401 animals were included. Ginsenoside Rg1 was significantly correlated with blood glucose (BG), insulin levels, body weight, superoxide dismutase (SOD), malondialdehyde (MDA), tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6) levels. In addition, according to subgroup analysis, the hypoglycemic, anti-inflammatory, and antioxidant effects of ginsenoside Rg1 in type 2 diabetic animals were not affected by experimental species, modeling, experimental drug dosage, or course of treatment. Conclusion: This meta-analysis presents a summary of the hypoglycemic effects of ginsenoside Rg1, which are achieved through anti-inflammatory and antioxidant mechanisms. These findings provide evidence-based support for the medical efficacy of ginsenoside Rg1. Specifically, ginsenoside Rg1 reduced MDA levels and restored SOD activity to exert its antioxidant activity. It had a positive effect on the reduction of IL-6 and TNF-α levels. However, the inclusion of studies with low methodological quality and the presence of publication bias may undermine the validity of the results. Further investigation with a more rigorous experimental design and comprehensive studies is necessary to fully understand the specific glycemic mechanisms of ginsenosides. Systematic Review Registration: https://www.crd.york.ac.uk/PROSPERO/, identifier https://CRD42023386830.

Protective role of nitric oxide donors on endothelium in ischemia-reperfusion injury: a meta-analysis of randomized controlled trials

BACKGROUND

Decreased bioavailability of nitric oxide (NO) under hypoxic conditions can lead to endothelial dysfunction. NO supplementation may protect endothelial function in ischemia-reperfusion (IR) injury. Therefore, a meta-analysis of randomized controlled trials (RCTs) was performed to verify the protective effect of NO donors on endothelium in IR injury.

METHODS

Medline, Embase, Cochrane Library, and Web of Science databases were searched from inception to April 1, 2023. The specific inclusion criteria were as follows: (1) RCTs; (2) trials comparing NO donors with placebo control groups; and (3) trials reporting the effects of these interventions on vascular endothelial functional outcomes in IR injury. Random-effects models were used to assess pooled effect sizes, which were expressed as standardized mean differences (SMD).

RESULTS

Seven studies satisfied the inclusion criteria and consisted of a total of 149 participants. NO donors were protective of endothelial function in IR injury (SMD: - 1.60; 95% confidence interval [CI]: - 2.33, - 0.88, P < 0.0001; heterogeneity [I² = 66%, P = 0.001]). Results of the subgroup analysis showed the following: absence of protective effect of NO donor use following ischemia on endothelial function in IR injury - 1.78 (95% CI: - 2.50, - 1.07) and loss of protective effect on endothelial function after prolonged NO donor use - 0.89 (95% CI: - 2.06, 0.28).

CONCLUSION

The short-period use of NO donors before the onset of ischemia can protect endothelial function in IR injury.

New Therapeutic Approaches to and Mechanisms of Ginsenoside Rg1 against Neurological Diseases

Neurological diseases, including Parkinson’s disease (PD), Alzheimer’s disease (AD), Huntington’s disease (HD), stroke, cerebral infarction, ischemia-reperfusion injury, depression and, stress, have high incidence and morbidity and often lead to disability. However, there is no particularly effective medication against them. Therefore, finding drugs with a suitable efficacy, low toxicity and manageable effects to improve the quality of life of patients is an urgent problem. Ginsenoside Rg1 (Rg1) is the main active component of ginseng and has a variety of pharmacological effects. In this review, we focused on the therapeutic potential of Rg1 for improving neurological diseases. We introduce the mechanisms of Ginsenoside Rg1 in neurological diseases, including apoptosis, neuroinflammation, the microRNA (miRNA) family, the mitogen-activated protein kinase (MAPK) family, oxidative stress, nuclear factor-κB (NF-κB), and learning and memory of Rg1 in neurological diseases. In addition, Rg1 can also improve neurological diseases through the interaction of different signal pathways. The purpose of this review is to explore more in-depth ideas for the clinical treatment of neurological diseases (including PD, AD, HD, stroke, cerebral infarction, ischemia–reperfusion injury, depression, and stress). Therefore, Rg1 is expected to become a new therapeutic method for the clinical treatment of neurological diseases.

Evaluation of Melatonin Therapy in Patients with Myocardial Ischemia-Reperfusion Injury: A Systematic Review and Meta-Analysis

Objectives

We conducted a meta-analysis to quantitatively evaluate the effect of melatonin therapy on patients with myocardial ischemia-reperfusion injury (MIRI) and explore the influencing factors.

Background

Although preclinical studies have shown that melatonin can alleviate MIRI, its protective effect on MIRI in patients remains controversial.

Methods

We searched PubMed, the Cochrane Library, and Embase. The primary outcome was cardiac function (left ventricular ejection fraction [LVEF], left ventricular end-diastolic volume [LVEDV], and left ventricular end-systolic volume [LVESV]) and myocardial infarct parameters (total left ventricular mass and infarct size).

Results

We included nine randomized controlled clinical trials with 631 subjects. Our results showed that melatonin had no significant effects on the primary outcome, but subgroup analyses indicated that when melatonin was administered by intravenous and intracoronary injection at the early stage of myocardial ischemia, LVEF was improved (<3.5 h; standardized mean difference [SMD]:0.50; 95% CI: 0.06 to 0.94; P = 0.03) and the infarct size was reduced (<2.5 h, SMD: −0.86; 95% CI: −1.51 to −0.22; P = 0.01), whereas when melatonin was injected at the late stage of myocardial ischemia (≥3.5 h or 2.5 h), the results were the opposite. Furthermore, melatonin intervention reduced the level of cardiac injury markers, inflammatory cytokines, oxidation factors, and increased the level of antioxidant factors (P < 0.001).

Conclusions

The results indicated that the cardioprotective function of melatonin for MIRI was influenced by the route and timing regimen of melatonin administration; the mechanism of which may be associated with the production of inflammatory cytokines, the balance of oxidation, and antioxidant factors.

Ginsenosides in central nervous system diseases: Pharmacological actions, mechanisms, and therapeutics

The nervous system is one of the most complex physiological systems, and central nervous system diseases (CNSDs) are serious diseases that affect human health. Ginseng (Panax L.), the root of Panax species, are famous Chinese herbs that have been used for various diseases in China, Japan, and Korea since ancient times, and remain a popular natural medicine used worldwide in modern times. Ginsenosides are the main active components of ginseng, and increasing evidence has demonstrated that ginsenosides can prevent CNSDs, including neurodegenerative diseases, memory and cognitive impairment, cerebral ischemia injury, depression, brain glioma, multiple sclerosis, which has been confirmed in numerous studies. Therefore, this review summarizes the potential pathways by which ginsenosides affect the pathogenesis of CNSDs mainly including antioxidant effects, anti-inflammatory effects, anti-apoptotic effects, and nerve protection, which provides novel ideas for the treatment of CNSDs.

Targeting Mitochondria by Plant Secondary Metabolites: A Promising Strategy in Combating Parkinson's Disease

Parkinson’s disease (PD) is one of the most prevalent and debilitating neurodegenerative conditions, and is currently on the rise. Several dysregulated pathways are behind the pathogenesis of PD; however, the critical targets remain unclear. Accordingly, there is an urgent need to reveal the key dysregulated pathways in PD. Prevailing reports have highlighted the importance of mitochondrial and cross-talked mediators in neurological disorders, genetic changes, and related complications of PD. Multiple pathophysiological mechanisms of PD, as well as the low efficacy and side effects of conventional neuroprotective therapies, drive the need for finding novel alternative agents. Recently, much attention has been paid to using plant secondary metabolites (e.g., flavonoids/phenolic compounds, alkaloids, and terpenoids) in the modulation of PD-associated manifestations by targeting mitochondria. In this line, plant secondary metabolites have shown promising potential for the simultaneous modulation of mitochondrial apoptosis and reactive oxygen species. This review aimed to address mitochondria and multiple dysregulated pathways in PD by plant-derived secondary metabolites.

A review of the functions of G protein-coupled estrogen receptor 1 in vascular and neurological aging

Aging-related diseases, especially vascular and neurological disorders cause huge economic burden. How to delay vascular and neurological aging is one of the insurmountable questions. G protein-coupled estrogen receptor 1 (GPER) has been extensively investigated in recent years due to its multiple biological responses. In this review, the function of GPER in aging-related diseases represented by vascular diseases, and neurological disorders were discussed. Apart from that, activation of GPER was also found to renovate the aging brain characterized by memory decline, but in a manner different from another two nuclear estrogen receptors estrogen receptor (ER)α and ERβ. This salutary effect would be better clarified from the aspects of synaptic inputs and transmission. Furthermore, we carefully described molecular mechanisms underpinning GPER-mediated effects. This review would update our understanding of GPER in the aging process. Targeting GPER may represent a promising strategy in the aging-related disorders.

The effect of ginsenosides on depression in preclinical studies: A systematic review and meta-analysis

BACKGROUND

Many ginsenosides have been shown to be efficacious for major depressive disorder (MDD), which is a highly recurrent disorder, through several preclinical studies. We aimed to review the literature assessing the antidepressant effects of ginsenosides on MDD animal models, to establish systematic scientific evidence in a rigorous manner.

METHODS

We performed a systematic review on the antidepressant effects of ginsenoside evaluated in in vivo studies. We searched for preclinical trials from inception to July 2019 in electronic databases such as Pubmed and Embase. In vivo studies examining the effect of a single ginsenoside on animal models of primary depression were included. Items of each study were evaluated by two independent reviewers. A meta-analysis was conducted to assess behavioral changes induced by ginsenoside Rg1, which was the most studied ginsenoside. Data were pooled using the random-effects models.

RESULTS

A total of 517 studies were identified, and 23 studies were included in the final analysis. They reported on many ginsenosides with different antidepressant effects and biological mechanisms of action. Of the 12 included articles assessing ginsenoside Rg1, pooled results of forced swimming test from 9 articles (mean difference (MD): 20.50, 95% CI: 16.13-24.87), and sucrose preference test from 11 articles (MD: 28.29, 95% CI: 22.90-33.69) showed significant differences compared with vehicle treatment. The risk of bias of each study was moderate, but there was significant heterogeneity across studies.

CONCLUSION

These estimates suggest that ginsenosides, including ginsenoside Rg1, reduces symptoms of depression, modulates underlying mechanisms, and can be a promising antidepressant.

Pseudoginsenoside F11 Enhances the Viability of Random-Pattern Skin Flaps by Promoting TFEB Nuclear Translocation Through AMPK-mTOR Signal Pathway

Random-pattern skin flap is widely used in tissue reconstruction. However, necrosis occurring in the distal part of the flap limits its clinical application to some extent. Activation of autophagy has been considered as an effective approach to enhance the survival of skin flaps. Pseudoginsenoside F11 (PF11), an ocotillol-type saponin, is an important component of Panax quinquefolium which has been shown to confer protection against cerebral ischemia and alleviate oxidative stress. However, it is currently unknown whether PF11 induces autophagy to improve the survival of skin flaps. In this study, we investigated the effects of PF11 on blood flow and tissue edema. The results of histological examination and western blotting showed that PF11 enhanced angiogenesis, alleviated apoptosis and oxidative stress, thereby improving the survival of the flap. Further experiments showed that PF11 promoted nuclear translocation of TFEB and by regulating the phosphorylation of AMPK. In summary, this study demonstrates that PF11 activates autophagy through the AMPK-TFEB signal pathway in skin flaps and it could be a promising strategy for enhancing flap viability.

Effect of ginsenoside-Rg1 on experimental Parkinson's disease: A systematic review and meta-analysis of animal studies

Previous studies have reported that ginsenoside-Rg1 (G-Rg1) was able to mitigate the loss of dopaminergic neurons in animal models of Parkinson's disease (PD). The present study provided a systematic review and meta-analysis of preclinical studies to pool current evidence on the effect of G-Rg1 on neurogenesis in the treatment of PD. Eligible studies were identified through a search from six databases: PubMed, EMBASE, Web of Science, VIP, Chinese National Knowledge Infrastructure and the Wanfang database. Primary outcomes were tyrosine hydroxylase (TH)-positive cells in the nigra, Nissl staining-positive cells in the nigra, pole test time and dopamine (DA) levels in the striatum. A total of 18 eligible studies were identified, involving 343 animals. Of these, 13 reported a significant relationship between G-Rg1 and improved TH-positive cells in the nigra compared with the control group (P<0.00001). Furthermore, 3 studies reported a significant relationship between G-Rg1 and improved Nissl-positive cells in the nigra compared with the control group (P<0.00001). In addition, 4 studies reported a significant effect of G-Rg1 to reduce the total pole test time compared with that in the control group (P=0.001). A total of 3 studies indicated a significant association between G-Rg1 and improved DA levels in the striatum compared with the control group (P<0.00001). These results suggested that G-Rg1 has positive effects in attenuating damage in models of PD, and thus, it is a potential candidate neuroprotective drug for human PD.

Exploration of tissue distribution of ginsenoside Rg1 by LC-MS/MS and nanospray desorption electrospray ionization mass spectrometry

Ginsenoside Rg1 (Rg1) was one of the dominent active components in several Panax medicinal species as Panax notoginseng and Panaxginseng with diversified bioactivities. However, the study on tissue distribution of Rg1 remained limited and needed to be further explored for elucidation of its spatial distribution. In the present study, a LC-MS/MS combined with nanospray desorption electrospray ionization (DESI) mass spectrometry method was developed for exploration of tissue distribution of Rg1 at different time points after intravenous administration to rats. Furthermore, a MS inlet-heat method was developed to improve the imaging efficacy of Rg1 in brain tissue. The results obtained from LC-MS/MS analysis indicated that kidney possessed the highest tissue concentration, followed by liver, lung, spleen, heart and brain. Meanwhile, the elimination of Rg1 was swift within 1 h. For the spatial distribution of Rg1 by DESI-MS, Rg1 mainly accumulated in the pelvis section of kidney. Meanwhile, the imaging result of brain implied that Rg1 might be distributed in the pons and medulla oblongata region of brain at 15 min after intravenous administration. It is anticipated that the data on tissue distribution of Rg1 could provide references for further probing its efficacy and drug development.

Meta-Analysis of Sleep Deprivation Effects on Patients With Depression

Objective: Depression is a common disorder with a high recurrence rate. Since the effect of sleep deprivation on depression in existing studies were inconsistent, the present study aimed to reassess the effects of SD on patients by performing a meta-analysis of updated research. Methods: PubMed, Embase, the Cochrane Library, and Web of Science were searched for articles before January 20th, 2021. Data on participant characteristics, SD characteristics, adjunctive method and tests for depression were extracted. A comprehensive analysis was conducted to assess the effect of SD on depression and subgroup analysis was used to determine the sources of heterogeneity. Results: In total, 8 articles were included. An SD time of <7 days slightly worsened depression levels [0.24 (-0.21, 0.69); I ² = 0%; P = 0.43], a time of 7-14 days had antidepressant effects [-1.52 (-2.07, -0.97); I ² = 19.6%; P = 0.288], and a time of more than 14 days also worsened depression [0.76 (0.12, 1.40); I ² = 43.7%; P = 0.169]. Conclusion: SD may serve as an effective antidepressant measure in humans when the time was 7-14 days, while a time of <7 days and more than 14 days worsened depression.

Probiotics treatment improves cognitive impairment in patients and animals: A systematic review and meta-analysis

The gut-brain axis has received considerable attention in recent years, and the "psychobiotics" concept indicates that probiotics have a potential positive effect on cognitive function. Therefore, the aim of this study was to quantitatively evaluate the influence of probiotics on cognition. We conducted a random-eff ;ects meta-analysis of 7 controlled clinical trials and 11 animals studies to evaluate the eff ;ects of probiotics on cognitive function. Probiotics supplementation enhanced cognitive function in both human (0.24 [0.05-0.42]; I² = 0 %) and animal studies (0.90 [0.47-1.34]; I² = 74 %). Subgroup analyses indicated that the effects of probiotics on cognitively impaired individuals (0.25 [0.05-0.45]; I² = 0 %) were greater than those on healthy ones (0.15 [-0.30 to 0.60]; I² = 0 %). Furthermore, compared with a multiple-probiotic supplement, a single strain of probiotics was more effective in humans. The meta-analysis provided some suggestions for probiotics intervention and tended to support a customized approach for different individuals to ameliorate cognitive disorders. Future additional clinical trials are necessary to evaluate therapeutic effect and influencing factors.

Natural Products and Their Bioactive Compounds: Neuroprotective Potentials against Neurodegenerative Diseases

In recent years, natural products, which originate from plants, animals, and fungi, together with their bioactive compounds have been intensively explored and studied for their therapeutic potentials for various diseases such as cardiovascular, diabetes, hypertension, reproductive, cancer, and neurodegenerative diseases. Neurodegenerative diseases, including Alzheimer's disease, Huntington's disease, Parkinson's disease, and amyotrophic lateral sclerosis are characterized by the progressive dysfunction and loss of neuronal structure and function that resulted in the neuronal cell death. Since the multifactorial pathological mechanisms are associated with neurodegeneration, targeting multiple mechanisms of actions and neuroprotection approach, which involves preventing cell death and restoring the function to damaged neurons, could be promising strategies for the prevention and therapeutic of neurodegenerative diseases. Natural products have emerged as potential neuroprotective agents for the treatment of neurodegenerative diseases. This review focused on the therapeutic potential of natural products and their bioactive compounds to exert a neuroprotective effect on the pathologies of neurodegenerative diseases.

Ginsenosides: potential therapeutic source for fibrosis-associated human diseases

Tissue fibrosis is an eventual pathologic change of numerous chronic illnesses, which is characterized by resident fibroblasts differentiation into myofibroblasts during inflammation, coupled with excessive extracellular matrix deposition in tissues, ultimately leading to failure of normal organ function. Now, there are many mechanistic insights into the pathogenesis of tissue fibrosis, which facilitate the discovery of effective antifibrotic drugs. Moreover, many chronic diseases remain a significant clinical unmet need. For the past five years, many research works have undoubtedly addressed the functional dependency of ginsenosides in different types of fibrosis and the successful remission in various animal models treated with ginsenosides. Caveolin-1, interleukin, thrombospondin-1 (TSP-1), liver X receptors (LXRs), Nrf2, microRNA-27b, PPARδ-STAT3, liver kinase B1 (LKB1)-AMPK, and TGF-β1/Smads are potential therapy targeting using ginsenosides. Ginsenosides can play a targeting role and suppress chronic inflammatory response, collagen deposition, and epithelial-mesenchymal transition (EMT), as well as myofibroblast activation to attenuate fibrosis. In this report, our aim was to focus on the therapeutic prospects of ginsenosides in fibrosis-related human diseases making use of results acquired from various animal models. These findings should provide important therapeutic clues and strategies for the exploration of new drugs for fibrosis treatment.

Efficacy and Mechanism of Panax Ginseng in Experimental Stroke

Stroke is one of the leading causes of death and long-term disability worldwide. However, effective therapeutic approaches are still limited. The disruption of blood supply triggers complicated temporal and spatial events involving hemodynamic, biochemical, and neurophysiologic changes, eventually leading to pathological disturbance and diverse clinical symptoms. Ginseng (Panax ginseng), a popular herb distributed in East Asia, has been extensively used as medicinal and nutritional supplements for a variety of disorders worldwide. In recent years, ginseng has displayed attractive beneficial effects in distinct neurological disorders including stroke, involving multiple protective mechanisms. In this article, we reviewed the literature on ginseng studies in the experimental stroke field, particularly focusing on the in vivo evidence on the preventive or therapeutic efficacy and mechanisms of ginseng and ginsenosides in various stroke models of mice and rats. We also summarized the efficacy and underlying mechanisms of ginseng and ginsenosides on short- and long-term stroke outcomes.

Ginsenoside Rb1 protects dopaminergic neurons from inflammatory injury induced by intranigral lipopolysaccharide injection

Accumulating studies suggest that neuroinflammation characterized by microglial overactivation plays a pivotal role in the pathogenesis of Parkinson’s disease. As such, inhibition of microglial overactivation might be a promising treatment strategy to delay the onset or slow the progression of Parkinson’s disease. Ginsenoside Rb1, the most active ingredient of ginseng, reportedly exerts neuroprotective effects by suppressing inflammation in vitro. The present study aimed to evaluate the neuroprotective and anti-inflammatory effects of ginsenoside Rb1 in a lipopolysaccharide-induced rat Parkinson’s disease model. Rats were divided into four groups. In the control group, sham-operated rats were intraperitoneally administered normal saline for 14 consecutive days. In the ginsenoside Rb1 group, ginsenoside Rb1 (20 mg/kg) was intraperitoneally injected for 14 consecutive days after sham surgery. In the lipopolysaccharide group, a single dose of lipopolysaccharide was unilaterally microinjected into the rat substantial nigra to establish the Parkinson’s disease model. Lipopolysaccharide-injected rats were treated with normal saline for 14 consecutive days. In the ginsenoside Rb1 + lipopolysaccharide group, lipopolysaccharide was unilaterally microinjected into the rat substantial nigra. Subsequently, ginsenoside Rb1 was intraperitoneally injected for 14 consecutive days. To investigate the therapeutic effects of ginsenoside Rb1, behavioral tests were performed on day 15 after lipopolysaccharide injection. We found that ginsenoside Rb1 treatment remarkably reduced apomorphine-induced rotations in lipopolysaccharide-treated rats compared with the lipopolysaccharide group. To investigate the neurotoxicity of lipopolysaccharide and potential protective effect of ginsenoside Rb1, contents of dopamine and its metabolites in the striatum were measured by high-performance liquid chromatography. Compared with the lipopolysaccharide group, ginsenoside Rb1 obviously attenuated the lipopolysaccharide-induced depletion of dopamine and its metabolites in the striatum. To further explore the neuroprotective effect of ginsenoside Rb1 against lipopolysaccharide-induced neurotoxicity, immunohistochemistry and western blot assay of tyrosine hydroxylase were performed to evaluate dopaminergic neuron degeneration in the substantial nigra par compacta. The results showed that lipopolysaccharide injection caused a large loss of tyrosine hydroxylase-immunoreactive neurons in the substantia nigra and a significant decrease in overall tyrosine hydroxylase expression. However, ginsenoside Rb1 noticeably reversed these changes. To investigate whether the neuroprotective effect of ginsenoside Rb1 was associated with inhibition of lipopolysaccharide-induced microglial activation, we examined expression of the microglia marker Iba-1. Our results confirmed that lipopolysaccharide injection induced a significant increase in Iba-1 expression in the substantia nigra; however, ginsenoside Rb1 effectively suppressed lipopolysaccharide-induced microglial overactivation. To elucidate the inhibitory mechanism of ginsenoside Rb1, we examined expression levels of inflammatory mediators (tumor necrosis factor-α, interleukin-1β, inducible nitric oxide synthase, and cyclooxygenase 2) and phosphorylation of nuclear factor kappa B signaling-related proteins (IκB, IKK) in the substantia nigra with enzyme-linked immunosorbent and western blot assays. Our results revealed that compared with the control group, phosphorylation and expression of inflammatory mediators IκB and IKK in the substantia nigra of lipopolysaccharide group rats were significantly increased; whereas, ginsenoside Rb1 obviously reduced lipopolysaccharide-induced changes on the lesioned side of the substantial nigra par compacta. These findings confirm that ginsenoside Rb1 can inhibit inflammation induced by lipopolysaccharide injection into the substantia nigra and protect dopaminergic neurons, which may be related to its inhibition of the nuclear factor kappa B signaling pathway. This study was approved by the Experimental Animal Ethics Committee of Shandong University of China in April 2016 (approval No. KYLL-2016-0148).

Protective Effects and Target Network Analysis of Ginsenoside Rg1 in Cerebral Ischemia and Reperfusion Injury: A Comprehensive Overview of Experimental Studies

Cerebral ischemia-reperfusion is a complicated pathological process. The injury and cascade reactions caused by cerebral ischemia and reperfusion are characterized by high mortality, high recurrence, and high disability. However, only a limited number of antithrombotic drugs, such as recombinant tissue plasminogen activator (r-TPA), aspirin, and heparin, are currently available for ischemic stroke, and its safety concerns is inevitable which associated with reperfusion injury and hemorrhage. Therefore, it is necessary to further explore and examine some potential neuroprotective agents with treatment for cerebral ischemia and reperfusion injury to reduce safety concerns caused by antithrombotic drugs in ischemic stroke. Ginseng Rg1 (G-Rg1) is a saponin composed of natural active ingredients and derived from the roots or stems of Panax notoginseng and ginseng in traditional Chinese medicine. Its pharmacological effects exert remarkable neurotrophic and neuroprotective effects in the central nervous system. To explore and summarize the protective effects and mechanisms of ginsenoside Rg1 against cerebral ischemia and reperfusion injury, we conducted this review, in which we searched the PubMed database to obtain and organize studies concerning the pharmacological effects and mechanisms of ginsenoside Rg1 against cerebral ischemia and reperfusion injury. This study provides a valuable reference and clues for the development of new agents to combat ischemic stroke. Our summarized review and analysis show that the pharmacological effects of and mechanisms underlying ginsenoside Rg1 activity against cerebral ischemia and reperfusion injury mainly involve 4 sets of mechanisms: anti-oxidant activity and associated apoptosis via the Akt, Nrf2/HO-1, PPARγ/HO-1, extracellular regulated protein kinases (ERK), p38, and c-Jun N-terminal kinase (JNK) pathways (or mitochondrial apoptosis pathway) and the caspase-3/ROCK1/MLC pathway; anti-inflammatory and immune stimulatory-related activities that involve apoptosis or necrosis via MAPK pathways (the JNK1/2 + ERK1/2 and PPARγ/HO-1 pathways), endoplasmic reticulum stress (ERS), high mobility group protein1 (HMGB1)-induced TLR2/4/9 and receptor for advanced glycation end products (RAGE) pathways, and the activation of NF-κB; neurological cell cycle, proliferation, differentiation, and regeneration via the MAPK pathways (JNK1/2 + ERK1/2, PI3K-Akt/mTOR, PKB/Akt and HIF-1α/VEGF pathways); and energy metabolism and the regulation of cellular ATP levels, the blood-brain barrier and other effects via N-methyl-D-aspartic acid (NMDA) receptors, ERS, and AMP/AMPK-GLUT pathways. Collectively, these mechanisms result in significant neuroprotective effects against cerebral ischemic injury. These findings will be valuable in that they should further promote the development of candidate drugs and provide more information to support the application of previous findings in stroke clinical trials.

Therapeutic potential of Panax ginseng and its constituents, ginsenosides and gintonin, in neurological and neurodegenerative disorders: a patent review

INTRODUCTION

Ginseng, Panax ginseng, has been used for various diseases and proven its great efficacy in managing central nervous system diseases.

AREAS COVERED

This article covers the therapeutic potential of patents on ginseng and its active constituents to develop therapies for neurodegenerative and neurological disorders, since 2010. The literature review was provided using multiple search engines including Google Patent, Espacenet and US Patent in the field of neurodegenerative diseases, Alzheimer's disease, Parkinson's disease, cognitive, and neurological disorders.

EXPERT OPINION

The gathered data represented outstanding merits of ginseng in treatment of neurodegenerative and neurological disorders. These effects have been mediated by neurogenesis, anti-apoptotic and antioxidant properties, inhibition of mitochondrial dysfunction, receptor-operated Ca²⁺ channels, amyloid beta aggregation, and microglial activation as well as neurotransmitters modulation. However, these compounds have limited clinical application of for the prevention or treatment of neurodegenerative and neurological disorders. This might be due to incomplete data on their clinical pharmacokinetic and toxicity properties, and limited economic investments. There is an increasing trend in use of herbal medicines instead of chemical drugs, so it is time to make more attention to the application of ginseng, the grandfather of medicinal plants, from basic sciences to patients' bed.

Ethnopharmacological Approaches for Dementia Therapy and Significance of Natural Products and Herbal Drugs

Dementia is a clinical syndrome wherein gradual decline of mental and cognitive capabilities of an afflicted person takes place. Dementia is associated with various risk factors and conditions such as insufficient cerebral blood supply, toxin exposure, mitochondrial dysfunction, oxidative damage, and often coexisting with some neurodegenerative disorders such as Alzheimer's disease (AD), Huntington's disease (HD), and Parkinson's disease (PD). Although there are well-established (semi-)synthetic drugs currently used for the management of AD and AD-associated dementia, most of them have several adverse effects. Thus, traditional medicine provides various plant-derived lead molecules that may be useful for further medical research. Herein we review the worldwide use of ethnomedicinal plants in dementia treatment. We have explored a number of recognized databases by using keywords and phrases such as “dementia”, “Alzheimer's,” “traditional medicine,” “ethnopharmacology,” “ethnobotany,” “herbs,” “medicinal plants” or other relevant terms, and summarized 90 medicinal plants that are traditionally used to treat dementia. Moreover, we highlight five medicinal plants or plant genera of prime importance and discuss the physiological effects, as well as the mechanism of action of their major bioactive compounds. Furthermore, the link between mitochondrial dysfunction and dementia is also discussed. We conclude that several drugs of plant origin may serve as promising therapeutics for the treatment of dementia, however, pivotal evidence for their therapeutic efficacy in advanced clinical studies is still lacking.