Supplementation with Herbal Extracts to Promote Behavioral and Neuroprotective Effects in Experimental Models of Parkinson's Disease: A Systematic Review

TMT-based quantitative proteomics analysis of neuroprotective effects of Forsythoside A on the MPTP-induced Parkinson's disease mouse model

Parkinson's disease (PD) is a prevalent neurodegenerative disorder characteristized by the presence of dyskinesia and the progressive loss of dopaminergic neurons. Although certain drugs can mitigate the symptoms of PD, they are unable to delay the disease progression, and their prolonged use may result in complications. Therefore, there exists an urgent necessity to identify potential agents that can effectively delay PD progression with fewer side effects. Recent research has unveiled that several traditional Chinese medicines (TCM) exhibit neuroprotective properties in various models pertinent to PD. Forsythoside A (FSA), the primary bioactive compound derived from TCM Lianqiao, has undergone extensive research in animal models of Alzheimer's disease and cerebral ischemia. However, the investigation into the impact of FSA on PD is limited in existing research. In this study, we aimed to evaluate the neuroprotective effects of FSA on MPTP-induced PD mouse model. FSA demonstrated significant improvements in the behavioral and neuropathological changes triggered by MPTP in mice. Furthermore, it exerted a suppressive effect on the activations of astrocyte and microglia. Meanwhile, Tandem mass tag (TMT)-based quantitative proteomics of striatal tissue and bioinformatics analysis were performed to elucidate the underlying mechanisms of FSA on PD mouse model. Proteomics demonstrated a total of 68 differentially expressed proteins (DEPs) were identified between HFSA and MPTP groups including 26 upregulated and 42 downregulated. Systematic bioinformatics analysis of the 68 DEPs illustrated that they were predominantly related to estrogen signaling pathway and calcium signaling pathway. The related DEPs (PLCβ4, Grm2, HPAC and Cox4i1) expression levels were verified by Western blot. FSA effectively restored the altered expression of the four DEPs induced by MPTP. Summarily, FSA exerted remarkable neuroprotective effects in MPTP-induced mice. Further, our research may provide proteomics insights that contribute to the further exploration of FSA as a potential treatment for PD.

Endophytic Fusarium species, a unique bioresource for disaggregator of misfolded alpha-synuclein

Aggregation of α-synuclein into toxic oligomeric structures has been implicated in the pathogenesis of Parkinson's disease via several key stages of fibrillation, oligomerization, and aggregation. Disaggregation or prevention of aggregation has garnered a lot of attention as a therapeutic strategy to prevent or delay the progression of Parkinson's disease. It has been recently established that certain polyphenolic compounds and catechins present in plants and tea extracts exhibit the potential to inhibit the α-synuclein aggregation. However, their copious supply for therapeutic development is still unsolved. Herein, we report for the first time the disaggregation potential of α-synuclein by an endophytic fungus residing in tea leaves (Camellia sinensis). Briefly, a recombinant yeast expressing α-synuclein was used for pre-screening of 53 endophytic fungi isolated from tea using anti-oxidant activity as a marker for the disaggregation of the protein. One isolate #59CSLEAS exhibited 92.4% reduction in production of the superoxide ions, which were similar to the already established α-synuclein disaggregator, Piceatannol exhibiting 92.8% reduction. Thioflavin T assay further established that #59CSLEAS decreased the oligomerization of α-synuclein by 1.63-fold. Subsequently Dichloro-dihydro-fluorescein diacetate-based fluorescence assay exhibited a reduction in total oxidative stress in the recombinant yeast in the presence of fungal extract, thereby indicating the prevention of oligomerization. Oligomer disaggregation potential of the selected fungal extract was found to be 56.5% as assessed by sandwich ELISA assay. Using morphological as well as molecular methods, the endophytic isolate #59CSLEAS was identified as Fusarium sp. The sequence was submitted in the Genbank with accession number ON226971.1.

Chinese Herbal Products for Non-Motor Symptoms of Parkinson's Disease in Taiwan: A Population-Based Study

Objective: Combinations of Chinese herbal products (CHPs) are widely used for Parkinson’s disease (PD) in Taiwan. Thereby, we investigated the use of CHPs in patients with PD.

Methods: This study was a population-based cohort study that analyzed the data of patients with PD from the National Health Insurance Research Database. A total of 9,117 patients were selected from a random sample of one million individuals included in this database. We used multiple logistic regression models to estimate the adjusted odds ratios of the demographic factors and analyzed the formula and single CHPs commonly used for PD.

Results: Traditional Chinese medicine users were more commonly female, younger, of white-collar status, and residents of Central Taiwan. Chaihu-Jia-Longgu-Muli-Tang was the most commonly used formula, followed by Ma-Zi-Ren-Wan and then Shao-Yao-Gan-Cao-Tang. The most commonly used single herb was Uncaria tomentosa (Willd. ex Schult.) DC., followed by Gastrodia elata Blume and then Radix et Rhizoma Rhei (Rheum palmatum L., Rheum tanguticum Maxim. ex Balf., and Rheum officinale Baill.). Chaihu-Jia-Longgu-Muli-Tang and U. tomentosa (Willd. ex Schult.) DC. have shown neuroprotective effects in previous studies, and they have been used for managing non-motor symptoms of PD.

Conclusion: Chaihu-Jia-Longgu-Muli-Tang and U. tomentosa (Willd. ex Schult.) DC. are the most commonly used CHPs for PD in Taiwan. Our results revealed the preferences in medication prescriptions for PD. Further studies are warranted to determine the effectiveness of these CHPs for ameliorating the various symptoms of PD, their adverse effects, and the mechanisms underlying their associated neuroprotective effects.

Efficacy of oral administration of licorice as an adjunct therapy on improving the symptoms of patients with Parkinson's disease, A randomized double blinded clinical trial

ETHNOPHARMACOLOGICAL RELEVANCE

Licorice preparations are used as neuroprotective remedies in Persian ethnomedicine, in order to prevent from disabilities in neurodegenerative conditions like Parkinson's disease (PD).

AIM OF THE STUDY

This study was designed to determine the licorice (root of Glycyrrhiza glabra L.) effectiveness as an adjunct treatment in the PD management.

MATERIAL AND METHODS

In this double-blinded trial, 128 patients were assessed for eligibility criteria. Seventy-eight patients were ineligible and 11 of them refused from participating. Thirty-nine PD patients (YAHR staging ≤ 3) were divided into two groups by random. The patients received oral licorice or placebo syrups with a dose of 5 cc, twice a day for 6 months. High-performance liquid chromatography and spectrophotometric instruments determined licorice syrup constituents. The patients' situation for Unified Parkinson's rating scale (UPDRS) was assessed every 6 weeks for the duration of six months. In addition, patients' blood pressure, blood glucose, sodium and potassium levels, quality of life and dizziness were determined.

RESULTS

Six weeks after intervention, total UPDRS, daily activities and tremor were significantly improved with a considerable effect size. A significant better motor test and rigidity scores were observed 4 months after licorice intake (p > 0.05). No electrolyte abnormality, significant changes in blood pressure or blood glucose levels were observed during the study. Each 5cc of syrup contained 136 mg of licorice extract with 12.14 mg glycyrrhizic acid, and also 136 μg of polyphenols.

CONCLUSION

The licorice intake could improve the symptoms in PD patients without serious adverse events.

Astragaloside IV Supplementation Promotes A Neuroprotective Effect in Experimental Models of Neurological Disorders: A Systematic Review

Background:

Neurological disorders constitute a growing worldwide concern due to the progressive aging of the population and the risky behavior they represent. Herbal medicines have scientific relevance in the treatment of these pathol-ogies. One of these substances, Astragaloside IV (AS-IV), is the main active compound present in the root of Astragalus membranaceus (Fisch.) Bge, a Chinese medicinal herb with neuroprotective properties.

Objective:

In the present study we performed a systematic review that sought to comprehend the neuroprotective effect pre-sented by AS-IV in experimental models of neurological disorders.

Method:

This study is a systematic review, where an electronic search in United States National Library of Medicine (Pub-Med), Science Direct, Cochrane Library, Scientific Electronic Library Online (SciELO), Scopus, Web of Science, Medline via Proquest and Periodicos Capes databases covering the years between 2007 and 2017, using “Astragaloside IV” and “Neurodegenerative diseases”; “Astragaloside IV” and “ Neurological disorders” as reference terms was made.

Results:

A total of 16 articles were identified, in which the efficacy of AS-IV was described in experimental models of Par-kinson’s disease, Alzheimer’s disease, cerebral ischemia and autoimmune encephalomyelitis, by improving motor deficits and/or neurochemical activity, especially antioxidant systems, reducing inflammation and oxidative stress.

Conclusion:

The findings of the present study indicate that the administration of AS-IV can improve behavioral and neuro-chemical deficits largely due to its antioxidant, antiapoptotic and anti-inflammatory properties, emerging as an alternative therapeutic approach for the treatment of neurological disorders.

Nanodelivery of phytobioactive compounds for treating aging-associated disorders

Aging population presents a major challenge for many countries in the world and has made the development of efficient means for healthspan extension a priority task for researchers and clinicians worldwide. Anti-aging properties including antioxidant, anti-inflammatory, anti-tumor, and cardioprotective activities have been reported for various phytobioactive compounds (PBCs) including resveratrol, quercetin, curcumin, catechin, etc. However, the therapeutic potential of orally administered PBCs is limited by their poor stability, bioavailability, and solubility in the gastrointestinal tract. Recently, innovative nanotechnology-based approaches have been developed to improve the bioactivity of PBCs and enhance their potential in preventing and/or treating age-associated disorders, primarily those caused by aging-related chronic inflammation. PBC-loaded nanoparticles designed for oral administration provide many benefits over conventional formulations, including enhanced stability and solubility, prolonged half-life, improved epithelium permeability and bioavailability, enhanced tissue targeting, and minimized side effects. The present review summarizes recent advances in this rapidly developing research area.

Supplementation with Curcuma longa Reverses Neurotoxic and Behavioral Damage in Models of Alzheimer's Disease: A Systematic Review

Background:

The formation of senile plaques and neurofibrillary tangles of the tau protein are the main pathological mechanism of Alzheimer’s disease (AD). Current therapies for AD offer discrete benefits to the clinical symptoms and do not prevent the continuing degeneration of neuronal cells. Therefore, novel therapeutic strategies have long been investigated, where curcumin (Curcuma longa) has shown some properties that can prevent the deleterious processes involved in neurodegenerative diseases.

Objective:

The aim of the present work is to review studies that addressed the effects of curcumin in experimental models (in vivo and in vitro) for AD.

Method:

This study is a systematic review conducted between January and June 2017, in which a consultation of scientific articles from indexed periodicals was carried out in Science Direct, United States National Library of Medicine (PubMed), Cochrane Library and Scielo databases, using the following descriptors: “Curcuma longa”, “Curcumin” and “Alzheimer’s disease”.

Results:

A total of 32 studies were analyzed, which indicated that curcumin supplementation reverses neurotoxic and behavioral damages in both in vivo and in vitro models of AD.

Conclusion:

The administration of curcumin in experimental models seems to be a promising approach in AD, even though it is suggested that additional studies must be conducted using distinct doses and through other routes of administration.

Devil's claw (Harpagophytum procumbens) and chronic inflammatory diseases: A concise overview on preclinical and clinical data

Devil's Claw is a traditional medicine that has been long used a wide range of health conditions, including indigestion, fever, allergic reactions, and rheumatism. The main compounds are iridoid glycosides, including harpagoside, harpagide, and procumbide. However, harpagoside is the most responsible for therapeutic activity, and its content is used as reference standard. Here, we analyzed and summarized preclinical and clinical studies focusing on therapeutic efficacy of devil's claw preparations in pathological conditions in which inflammation plays a key causative role.

A Systematic Review of Phytochemistry, Pharmacology and Pharmacokinetics on Astragali Radix: Implications for Astragali Radix as a Personalized Medicine

Astragali radix (AR) is one of the most widely used traditional Chinese herbal medicines. Modern pharmacological studies and clinical practices indicate that AR possesses various biological functions, including potent immunomodulation, antioxidant, anti-inflammation and antitumor activities. To date, more than 200 chemical constituents have been isolated and identified from AR. Among them, isoflavonoids, saponins and polysaccharides are the three main types of beneficial compounds responsible for its pharmacological activities and therapeutic efficacy. After ingestion of AR, the metabolism and biotransformation of the bioactive compounds were extensive in vivo. The isoflavonoids and saponins and their metabolites are the major type of constituents absorbed in plasma. The bioavailability barrier (BB), which is mainly composed of efflux transporters and conjugating enzymes, is expected to have a significant impact on the bioavailability of AR. This review summarizes studies on the phytochemistry, pharmacology and pharmacokinetics on AR. Additionally, the use of AR as a personalized medicine based on the BB is also discussed, which may provide beneficial information to achieve a better and more accurate therapeutic response of AR in clinical practice.

Plant Extracts and Phytochemicals Targeting α-Synuclein Aggregation in Parkinson's Disease Models

α-Synuclein (α-syn) is a presynaptic protein that regulates the release of neurotransmitters from synaptic vesicles in the brain. α-Syn aggregates, including Lewy bodies, are features of both sporadic and familial forms of Parkinson's disease (PD). These aggregates undergo several key stages of fibrillation, oligomerization, and aggregation. Therapeutic benefits of drugs decline with disease progression and offer only symptomatic treatment. Novel therapeutic strategies are required which can either prevent or delay the progression of the disease. The link between α-syn and the etiopathogenesis and progression of PD are well-established in the literature. Studies indicate that α-syn is an important therapeutic target and inhibition of α-syn aggregation, oligomerization, and fibrillation are an important disease modification strategy. However, recent studies have shown that plant extracts and phytochemicals have neuroprotective effects on α-syn oligomerization and fibrillation by targeting different key stages of its formation. Although many reviews on the antioxidant-mediated, neuroprotective effect of plant extracts and phytochemicals on PD symptoms have been well-highlighted, the antioxidant mechanisms show limited success for translation to clinical studies. The identification of specific plant extracts and phytochemicals that target α-syn aggregation will provide selective molecules to develop new drugs for PD. The present review provides an overview of plant extracts and phytochemicals that target α-syn in PD and summarizes the observed effects and the underlying mechanisms. Furthermore, we provide a synopsis of current experimental models and techniques used to evaluate plant extracts and phytochemicals. Plant extracts and phytochemicals were found to inhibit the aggregation or fibril formation of oligomers. These also appear to direct α-syn oligomer formation into its unstructured form or promote non-toxic pathways and suggested to be valuable drug candidates for PD and related synucleinopathy. Current evidences from in vitro studies require confirmation in the in vivo studies. Further studies are needed to ascertain their potential effects and safety in preclinical studies for pharmaceutical/nutritional development of these phytochemicals or dietary inclusion of the plant extracts in PD treatment.

An Overview of Systematic Reviews of Chinese Herbal Medicine for Parkinson's Disease

Parkinson's disease (PD) is a high prevalence neurodegenerative disorder without a disease-modifying therapy. Up to now, a number of systematic reviews have been conducted to evaluate efficacy and safety of Chinese herbal Medicine (CHM) for PD patients. Here, we aimed to assess the methodological quality and reporting quality of systematic reviews using an overview, and then synthesize and evaluate the available evidence level of CHM for PD. Six databases were searched from inception to September 2018. The literatures were selected and data were extracted according to prespecified criteria. A Measurement Tool to Assess Systematic Reviews (AMSTAR) was used to evaluate the quality of methodology, and Grading of Recommendations Assessment, Development, and Evaluation (GRADE) to determine the evidence quality of the primary outcome measures. A total of 11 systematic reviews with 230 RCTs of CHM for PD were included. AMSTAR scores of the included reviews were range from 4 to 9. Compared with conventional western medicine (WCM), CHM paratherapy showed significant effect in improving UPDRS score, Webster scale score, PDQ-39, NMSQuest, CHM Syndrome Integral Scale, and PDSS. However, CHM monotherapy showed no difference relative to WCM according to various outcome measures. Adverse events were reported in 9 systematic reviews. The side effect in CHM paratherapy group was generally less than or lighter than that in WCM group. The quality of the evidence of primary outcomes was moderate (42%) to high (54%) according to the GRADE profiler. The present finding supported the use of CHM paratherapy for PD patients but we should treat the evidence cautiously because of the methodological flaws, whereas there is insufficient evidence of CHM monotherapy for PD.

Calycosin attenuates MPTP-induced Parkinson's disease by suppressing the activation of TLR/NF-κB and MAPK pathways

Parkinson is the second common neurodegenerative disease. The characteristics of Parkinson's disease (PD) are the dopamin neurons loss caused by neuroinflammation responses. C alycosin, an isoflavone phytoestrogen isolated from Astragalus membranaceus, has multiple pharmacological activities, such as anti-inflammation, anti-tumor, and neuroprotective effects. However, it is unknown whether calycosin can mitigate PD symptoms. This study aims to explore whether calycosin can alleviate PD symptoms and the underlying mechanisms. PD was induced in mice by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) injection, and calycosin was given intracerebroventricularly to these mice. A cell model of nerve inflammation was established by BV2 microglia cells injected with lipopolysaccharide (LPS). The motor states were evaluated by stepping, whisker, and cylinder experiments. The states of dopaminergic neurons and microglia were detected by immunostainning of tyrosine hydroxylase and cluster of differentiation molecule 11b (CD11b). The expression levels of inflammatory factors were detected by qPCR. Toll-like receptor (TLR)/nuclear factor kappa B (NF-κB) and mitogen-activated protein kinase (MAPK) pathways were investigated by western blot. We found that calycosin treatment mitigated the behavioral dysfunctions and inflammatory responses in MPTP-induced PD mice. The TLR/NF-κB and MAPK pathways in MPTP-induced PD mice were inhibited by calycosin treatment, which was coincident with experiments in LPS-induced BV2 cells. Above all, calycosin mitigates PD symptoms through TLR/NF-κB and MAPK pathways in mice and cell lines.

Jia-Jian-Di-Huang-Yin-Zi decoction exerts neuroprotective effects on dopaminergic neurons and their microenvironment

As a classical prescription of Traditional Chinese medicine, the Jia-Jian-Di-Huang-Yin-Zi (JJDHYZ) decoction has long been used to treat movement disorders. The present study evaluated the effects of JJDHYZ on dopaminergic (DA) neurons and their survival-enhancing microenvironment as well as the possible mechanisms involved using a mouse model of Parkinson's disease. In MPTP-lesioned mice, a high dosage of JJDHYZ (34 g/kg/day) attenuated the loss of DA neurons, reversed the dopamine depletion, and improved the expression of glial-derived neurotrophic factor (GDNF) compared to the untreated model group. JJDHYZ also protected the ultrastructure of the blood-brain barrier (BBB) and tight junction proteins by inhibiting the activation of microglia and astrocytes besides the increase in three types of matrix metalloproteinases in the substantia nigra. In conclusion, the JJDHYZ-high dosage (JJDHYZ-H) group exhibited the neuroprotection of DA neurons, and the underlying mechanism may be related to the survival-enhancing microenvironment of the DA neurons.

Recent developments in solid lipid nanoparticle and surface-modified solid lipid nanoparticle delivery systems for oral delivery of phyto-bioactive compounds in various chronic diseases

Solid lipid nanoparticle (SLN) delivery systems have a wide applicability in the delivery of phyto-bioactive compounds to treat various chronic diseases, including diabetes, cancer, obesity and neurodegenerative diseases. The multiple benefits of SLN delivery include improved stability, smaller particle size, leaching prevention and enhanced lymphatic uptake of the bioactive compounds through oral delivery. However, the burst release makes the SLN delivery systems inadequate for the oral delivery of various phyto-bioactive compounds that can treat such chronic diseases. Recently, the surface-modified SLN (SMSLN) was observed to overcome this limitation for oral delivery of phyto-bioactive compounds, and there is growing evidence of an enhanced uptake of curcumin delivered orally via SMSLNs in the brain. This review focuses on different SLN and SMSLN systems that are useful for oral delivery of phyto-bioactive compounds to treat various chronic diseases.