Neuroprotective effects of echinacoside in the mouse MPTP model of Parkinson's disease

Echinacoside: A promising active natural products and pharmacological agents

Echinacoside, a natural phenylethanoid glycoside, was discovered and isolated from the garden plant Echinacea angustifolia DC., belonging to the Compositae family, approximately sixty years ago. Extensive investigations have revealed that it possesses a wide array of pharmacologically beneficial activities for human health, particularly notable for its neuroprotective and anticancer activity. Several crucial concerns surfaced, encompassing the recognition of active metabolites that exhibited inadequate bioavailability in their prototype form, the establishment of precise molecular signal pathways or targets associated with the aforementioned effects of echinacoside, and the scarcity of dependable clinical trials. Hence, the question remains unanswered as to whether scientific research can effectively utilize this natural compound. To support future studies on this natural product, it is imperative to provide a systematic overview and insights into potential future prospects. The current review provides a comprehensive analysis of the existing knowledge on echinacoside, encompassing its wide distribution, structural diversity and metabolism, diverse therapeutic applications, and improvement of echinacoside bioavailability for its potential utilization.

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

ETHNOPHARMACOLOGICAL RELEVANCE

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

AIM OF THE STUDY

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSION

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

Protective effect of cistanoside A on dopaminergic neurons in Parkinson's disease via mitophagy

One of the main pathological features of Parkinson's disease (PD) is the loss of dopaminergic neurons in the substantia nigra compacta (SNc). Cistanoside A (CA) has a strong neuroprotective effect in PD, but the exact mechanism is unclear. In the present study, the MPTP-stimulated mouse model of PD and MPP⁺ -treated PD model in the MES23.5 neuronal cell model of PD were used to investigate the neuroprotective effects of CA on PD and its potential mechanism. The in vivo experiment results indicated that CA improved the motor function in mice and increased the number of tyrosine hydroxylase positive cells in SNc. In vitro experiments showed that CA reduced the MPP⁺ -induced decrease in neurons and mitochondrial membrane potential and promoted the activation of autophagosomes. Furthermore, we found that CA promoted the recruitment of PINK1 and Parkin aggregation to impair mitochondrial membranes and inhibited mitochondrial damage via LC3- and p62-mediated autophagy. In conclusion, CA protects against MPTP-induced neurotoxicity in vivo and MPP⁺ -induced neurotoxicity in vitro, possibly by promoting the PINK1/Parkin/p62 pathway to accelerate the degradation of damaged mitochondria thereby reducing oxidative stress.

ER stress and UPR in Alzheimer's disease: mechanisms, pathogenesis, treatments

Alzheimer's disease (AD) is a devastating neurodegenerative disorder characterized by gradual loss of memory and cognitive function, which constitutes a heavy burden on the healthcare system globally. Current therapeutics to interfere with the underlying disease process in AD is still under development. Although many efforts have centered on the toxic forms of Aβ to effectively tackle AD, considering the unsatisfactory results so far it is vital to examine other targets and therapeutic approaches as well. The endoplasmic reticulum (ER) stress refers to the build-up of unfolded or misfolded proteins within the ER, thus, perturbing the ER and cellular homeostasis. Emerging evidence indicates that ER stress contributes to the onset and development of AD. A thorough elucidation of ER stress machinery in AD pathology may help to open up new therapeutic avenues in the management of this devastating condition to relieve the cognitive dementia symptoms. Herein, we aim at deciphering the unique role of ER stress in AD pathogenesis, reviewing key findings, and existing controversy in an attempt to summarize plausible therapeutic interventions in the management of AD pathophysiology.

The pathogenesis and treatment mechanism of Parkinson's disease from the perspective of traditional Chinese medicine

BACKGROUND

Parkinson's disease (PD) is the second most common neurodegenerative disease with no treatment currently available to modify its progression. Traditional Chinese medicine (TCM) has gained attention for its unique theoretical basis and clinical effects. Many studies have reported on the clinical effects and pharmacological mechanisms of Chinese herbs in PD. However, few studies have focused on the treatment mechanisms of anti-PD TCM drugs from the perspective of TCM itself.

PURPOSE

To elaborate the treatment mechanisms of anti-PD TCM drugs in the perspective of TCM.

METHODS

We performed a literature survey using traditional books of Chinese medicine and online scientific databases including PubMed, Web of Science, Google Scholar, China National Knowledge Infrastructure (CNKI), and others up to July 2021.

RESULTS

TCM theory states that PD is caused by a dysfunction of the zang-fu organs (liver, spleen, kidney, and lung) and subsequent pathogenic factors (wind, fire, phlegm, and blood stasis). Based on the pathogenesis, removing pathogenic factors and restoring visceral function are two primary treatment principles for PD in TCM. The former includes dispelling wind, clearing heat, resolving phlegm, and promoting blood circulation, while the latter involves nourishing the liver and kidney and strengthening the spleen. The anti-PD mechanisms of the active ingredients of TCM compounds and herbs at different levels include anti-apoptosis, anti-inflammation, and anti-oxidative stress, as well as the restoration of mitochondrial function and the regulation of autophagy and neurotransmitters.

CONCLUSION

Chinese herbs and prescriptions can be used to treat PD by targeting multiple pharmacological mechanisms.

Echinacea purpurea (L.) Moench: Biological and Pharmacological Properties. A Review

Echinacea purpurea (L.) Moench (EP)is a perennial herbaceous flowering plant, commonly known as purple coneflower and it belongs to the Asteraceae family. The Echinacea genus is originally from North America, in the United States, and its species are widely distributed throughout. There are nine different species of Echinacea, but only three of them are used as medicinal plants with wide therapeutic uses: Echinacea purpurea (L.) Moench, Echinacea pallida (Nutt.) Nutt. and Echinacea angustifolia DC. Several significant groups of bioactive compounds with pharmacological activities have been isolated from Echinacea species. Numerous beneficial effects have been demonstrated about these compounds. The immunomodulatory effect was initially demonstrated, but over time other effects have also been highlighted. The present review gives a comprehensive summary of the chemical constituents, bioactive compounds, biological effects and therapeutical uses of purple coneflower. Research shows that such a well-known and recognized species needs to be further studied to obtain efficient products with a guarantee of the safety.

Echinacoside Protects Dopaminergic Neurons Through Regulating IL-6/JAK2/STAT3 Pathway in Parkinson’s Disease Model

Echinacoside (ECH), the major active constituent of Cistanche deserticola, was found to exert neuroprotection through neurotrophic and anti-inflammatory functions in Parkinson’s disease (PD) models. However, a clear intermediate molecule or pathway that unifies these two effects has to be found. In this study, our results demonstrate that ECH can protect DA neurons in PD mice with Western blot and immunohistochemistry staining. The quantitative real-time polymerase chain reaction was adapted to confirm its anti-inflammatory function with decreased cytokines (interleukin- (IL-) 6, IL-1β, and TNF-α) in PD mice and LPS-induced BV2 cells. Further studies found that ECH inhibited the IL-6/JAK2/STAT3 pathway and decreased phosphorylation of STAT3 on tyr705 by Western blot. It can also increase p-STAT3 (ser727) and brain-derived neurotrophic factor (BDNF) expression in PD mice and LPS-induced BV2 cells. This study revealed that ECH exerts neurotrophic and anti-inflammatory effects by regulating the IL-6/JAK2/STAT3 pathway and the phosphorylation of STAT3, promoting the mutually beneficial influence of the two effects to maximize its neuroprotective function.

Chemical profiles and metabolite study of raw and processed Cistanche deserticola in rats by UPLC-Q-TOF-MSE

Background

Chinese materia medica processing is a distinguished and unique pharmaceutical technique in Traditional Chinese Medicine (TCM) used for reducing side effects, and increasing or even changing therapeutic efficacy of the raw herbs.Changes in the essential components induced by an optimized processing procedure are primarily responsible for the increased efficacy of medicinal plants.The kidney-yang invigorating effect of rice wine-steamed Cistancha deserticola (C. deserticola) was stronger than raw C. deserticola (CD).

Methods

A comparison analysis was carried out using the UPLC-Q-TOF-MS^E with the UNIFI informatics platform to determine the influence of processing. In vitro studies were performed for the characterization of constituents as well as metabolites in vivo. The chemical components were determined in CD and its processed products. The multivariate statistical analyses were conducted to evaluate variations between them while OPLS-DA was used for pairwise comparison.

Results

The results of this study revealed considerable variations in phenylethanoid glycosides (PhGs) and iridoids after processing. A total of 97 compounds were detected in the extracts of CD and its processed product. PhGs having 4'-O-caffeoyl group in the 8-O-β-d-glucopyranosyl part, like acteoside, cistanoside C, campneoside II, osmanthuside decreased after being processed, while PhGs with 6'-O-caffeoyl group in the 8-O-β-d-glucopyranosyl part, such as isoacetoside, isocistanoside C, isocampneoside I, isomartynoside increased, especially in the CD-NP group. The intensity of echinacoside and cistanoside B whose structure possess 6'-O-β-d-glucopyranosyl moiety also increased. In in vivo study, 10 prototype components and 44 metabolites were detected in rat plasma, feces, and urine. The obtained results revealed that processing leads to the considerable variation in the chemical constituents of CD and affected the disposition of the compounds in vivo, and phase II metabolic processes are the key cascades of each compound and most of the metabolites are associated with echinacoside or acteoside.

Conclusions

This is the first global comparison research of raw and processed CD. These findings add to our understanding of the impact of CD processing and give important data for future efficacy investigations.

Herba Cistanche (Rou Cong Rong): A Review of Its Phytochemistry and Pharmacology

Herba Cistanche, known as Rou Cong Rong in Chinese, is a very valuable Chinese herbal medicine that has been recorded in the Chinese Pharmacopoeia. Rou Cong Rong has been extensively used in clinical practice in traditional herbal formulations and has also been widely used as a health food supplement for a long time in Asian countries such as China and Japan. There are many bioactive compounds in Rou Cong Rong, the most important of which are phenylethanoid glycosides. This article summarizes the up-to-date information regarding the phytochemistry, pharmacology, processing, toxicity and safety of Rou Cong Rong to reveal its pharmacodynamic basis and potential therapeutic effects, which could be of great value for its use in future research.

Tiron alleviates MPTP-induced Parkinsonism in mice via activation of Keap-1/Nrf2 pathway

Parkinsonism is a neurodegenerative disease that is common all over the world. This study aimed at exploring the neuroprotective effect of tiron against 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced Parkinsonism. MPTP (30 mg/kg, intraperitoneally [ip]) was injected in mice daily for 5 consecutive days. Mice were treated with tiron (140 and 280 mg/kg, ip) or levodopa (8.4 mg/kg, orally) for 10 consecutive days starting 5 days before MPTP injection. At the end of the experiment, behavioral tests were conducted to assess the neuroprotective effect of tiron. Moreover, oxidative stress was assessed via measuring antioxidant enzyme, such as catalase, and lipid peroxidation was evaluated as malondialdehyde. Neuronal damage was also detected by histopathological examination and via estimating hippocampal levels of dopamine, γ-aminobutyric acid, and nuclear factor erythroid-derived 2-like 2. In addition, the expression of Kelch-like ECH-associated protein 1 and heme oxygenase-1 was assessed by immunohistochemistry. Compared with the blank control group and the positive control group, the inhibitory effect of tiron on MPTP-induced neurodegenerative injury was statistically significant.

Echinacoside Suppresses Amyloidogenesis and Modulates F-actin Remodeling by Targeting the ER Stress Sensor PERK in a Mouse Model of Alzheimer's Disease

Endoplasmic reticulum stress (ERS) plays a vital and pathogenic role in the onset and progression of Alzheimer’s disease (AD). Phosphorylation of PKR-like endoplasmic reticulum kinase (PERK) induced by ERS depresses the interaction between actin-binding protein filamin-A (FLNA) and PERK, which promotes F-actin accumulation and reduces ER-plasma membrane (PM) communication. Echinacoside (ECH), a pharmacologically active component purified from Cistanche tubulosa, exhibits multiple neuroprotective activities, but the effects of ECH on ERS and F-actin remodeling remain elusive. Here, we found ECH could inhibit the phosphorylation of PERK. Firstly ECH can promote PERK-FLNA combination and modulate F-actin remodeling. Secondly, ECH dramatically decreased cerebral Aβ production and accumulation by inhibiting the translation of BACE1, and significantly ameliorated memory impairment in 2 × Tg-AD mice. Furthermore, ECH exhibited high affinity to either mouse PERK or human PERK. These findings provide novel insights into the neuroprotective actions of ECH against AD, indicating that ECH is a potential therapeutic agent for halting and preventing the progression of AD.

Herbal medicine for psychiatric disorders: Psychopharmacology and neuroscience-based nomenclature

Objectives: Herbs are frequently and concurrently used with prescribed drugs by patients worldwide. While clinical trials have found some herbs to be as useful as standard psychiatric drugs, most clinicians are unaware of their pharmacological mechanisms.Methods: We searched English language and other language literature with English abstracts listed in PubMed website, supplemented by additional through Google Scholar's free academic paper abstract website for publications on herbs, focussing on their clinical use in mental disorders, their neurobiology and their pharmacology.Results: A major reason for herbs remaining outside of mainstream psychiatry is that the terminology and concepts in herbal medicine are not familiar to psychiatrists in general. Many publications regarding the use of herbal medicine for psychiatric disorders are deficient in details regarding diagnosis, criteria for response and the neurobiology details compared with publications on standard psychotropic drugs. Nomenclature for herbal medicine is usually confusing and is not conducive to an easy understanding of their mode of action in psychiatric disorders.Conclusions: The recent neuroscience-based nomenclature (NbN) for psychotropics methodology would be a logical application to herbal medicine in facilitating a better understanding of the use of herbal medicine in psychiatry.

The Phenylethanol Glycoside Liposome Inhibits PDGF-Induced HSC Activation via Regulation of the FAK/PI3K/Akt Signaling Pathway

Cistanche tubulosa is a traditional Chinese herbal medicine that is widely used to regulate immunity, and phenylethanol glycosides (CPhGs) are among the primary components responsible for this activity. However, the application of CPhGs is negatively affected by their poor absorption and low oral utilization. Targeted drug delivery is an important development direction for pharmaceutics. Previous studies have indicated that CPhGs could block the conduction of the signaling pathways in TGF-β1/smad and inhibit the activation of hepatic stellate cells (HSCs). The aim of this study was to evaluate the anti-hepatic fibrosis effect of CPhG liposomes by inhibiting HSC activation, promoting apoptosis, blocking the cell cycle, suppressing the conduction of signaling pathways in focal adhesion kinase(FAK)/phosphatidylinositol-3-kinase(PI3K)/protein kinase B(Akt), and determining their in vitro hepatoprotective activity. In vitro release studies demonstrated that CPhG liposomes have a sustained release effect compared to drug CPhGs. HSC proliferation was inhibited after treatment with the CPhG liposomes (29.45, 14.72, 7.36 µg/mL), with IC50 values of 42.54 µg/mL in the MTT assay. Different concentrations of the CPhG liposomes could inhibit HSC proliferation, promote apoptosis, and block the cell cycle. The MTT method showed an obvious inhibition of HSC proliferation after CPhG liposome and Recombinant Rat Platelet-derived growth factor-BB(rrPDGF-BB) treatment. The levels of collagen-1, metallopeptidase inhibitor 1 (TIMP-1), α smooth muscle actin (α-SMA), and phosphorylated PI3K/Akt were downregulated, and matrix metalloproteinase-1 (MMP-1) was upregulated, by pretreatment with different concentrations of CPhG liposomes. Moreover, 29.45 μg/mL of CPhG liposomes could decrease the expression of the FAK protein and the phosphorylated PI3K and Akt protein downstream of FAK by overexpression of the FAK gene. This experiment suggests that CPhG liposomes may inhibit the activation of HSCs by inhibiting FAK and then reducing the expression of phosphorylated Akt/PI3K, thereby providing new insights into the application of CPhGs for liver fibrosis.

A Review of Biologically Active Natural Products from a Desert Plant Cistanche tubulosa

An Orobanchaceae plant Cistanche tubulosa (SCHENK) WIGHT (Kanka-nikujuyou in Japanese), which is one of the authorized plant resources as Cistanches Herba in both Japanese and Chinese Pharmacopoeias, is a perennial parasitic plant growing on roots of sand-fixing plants. The stems of C. tubulosa have traditionally been used for treatment of impotence, sterility, lumbago, and body weakness as well as a promoting agent of blood circulation. In recent years, Cistanches Herba has also been widely used as a health food supplement in Japan, China, and Southeast Asian countries. Here we review our recent studies on chemical constituents from the stems of C. tubulosa as well as their bioactivities such as vasorelaxtant, hepatoprotective, and glucose tolerance improving effects.

GRP78/BIP/HSPA5 as a Therapeutic Target in Models of Parkinson's Disease: A Mini Review

Parkinson's disease (PD) is a common neurodegenerative disorder characterized by selective loss of dopamine neurons in the substantia nigra pars compacta of the midbrain. Reports from postmortem studies in the human PD brain, and experimental PD models reveal that endoplasmic reticulum (ER) stress is implicated in the pathogenesis of PD. In times of stress, the unfolded or misfolded proteins overload the folding capacity of the ER to induce a condition generally known as ER stress. During ER stress, cells activate the unfolded protein response (UPR) to handle increasing amounts of abnormal proteins, and recent evidence has demonstrated the activation of the ER chaperone GRP78/BiP (78 kDa glucose-regulated protein/binding immunoglobulin protein), which is important for proper folding of newly synthesized and partly folded proteins to maintain protein homeostasis. Although the activation of this protein is essential for the initiation of the UPR in PD, there are inconsistent reports on its expression in various PD models. Consequently, this review article aims to summarize current knowledge on neuroprotective agents targeting the expression of GRP78/BiP in the regulation of ER stress in experimental PD models.

Echinacoside selectively rescues complex I inhibition-induced mitochondrial respiratory impairment via enhancing complex II activity

Previous investigations have implicated mitochondrial dysfunction characterized by Complex I deficiency in the death of dopaminergic neurons in Parkinson's disease (PD). To date, there are no efficient therapeutic approaches to rescue mitochondrial respiratory impairment or prevent neurodegeneration in PD. The beneficial effects of echinacoside (ECH) on neurodegeneration have been reported in both in vivo and in vitro studies, yet the mechanisms underlying remain elusive and little has been investigated concerning the influences of ECH on mitochondrial respiratory impairment. Here, we compared the protection of ECH on cell injury and mitochondrial dysfunction induced by various inhibitors of Complex I-IV using human neuroblastoma SH-SY5Y cell line. We found that ECH selectively attenuates cell injury, reverses mitochondrial depolarization and bioenergetic failure caused by Complex I inhibitors, whereas it has little protection against Complex II-IV inhibitors. Further investigation demonstrated that ECH enhances Complex II activity and mitochondrial respiration in the cells treated with Complex I inhibitors. This suggests that ECH selectively rescues Complex I inhibition-induced mitochondrial respiratory impairment though elevating Complex II activity, and further confirms that ECH might have a promising potential in PD treatment.

Inhibition of Amyloid Beta Aggregation and Deposition of Cistanche tubulosa Aqueous Extract

Cistanche tubulosa aqueous extract (CTE) is already used as a botanical prescription drug for treating dementia in China. Our previous studies reported that phenylethanoid glycosides of CTE have anti-Alzheimer's disease (AD) activity by inhibiting amyloid β peptide (Aβ) aggregation and deposition. However, recent studies considered that the phenylethanoid glycosides may be metabolized by intestinal bacteria, because all analysis results showed that the bioavailability of phenylethanoid glycosides is extremely low. In this study we demonstrate how iron chelation plays a crucial role in the Aβ aggregation and deposition inhibition mechanism of phenylethanoid glycosides of CTE. In addition, we further proved phenylethanoid glycosides (1⁻3) could reach brain. Active CTE component and action mechanism confirmation will be a great help for product quality control and bioavailability studies in the future. At the same time, we provide a new analysis method useful in determining phenylethanoid glycosides (1⁻3) in plants, foods, blood, and tissues for chemical fingerprint and pharmacokinetic research.

Echinacoside protects against MPTP/MPP+-induced neurotoxicity via regulating autophagy pathway mediated by Sirt1

Parkinson's disease (PD) is a common chronic neurodegenerative disease and greatly affects the quality of PD patients' life. Current symptomatic treatment of PD is limited. There are no effective treatment and drugs that could radically cure PD. Increasing experimental evidence has proven a causal relationship between alpha-synuclein (α-synuclein, α-syn) and the neuropathology of Parkinson's diseases, although the exact pathophysiological role of α-synuclein is not fully clarified. Previous studies showed that monomers and polymers of α-synuclein were secreted from damaged nerve cells via exocytosis and occupied healthy nerve cells via endocytosis, which afford evidence for the prion-like role of α-synuclein. Autophagy is the known mechanism for eukaryotic cells to degrade protein polymers and damaged organelles that proteasome does not cope with. Therefore, promoting the clearance of α-synuclein by enhancing autophagy in neuronal cells could be a promising treatment in the early stage of PD. SIRT1 is a potent regulator of autophagy, because it deacetylates a mass of important transcription factors such as Forkhead Box subgroup O (FoxO) transcription factors family. SIRT1's action relates to FoxO, because FoxO transcription factors are involved in various molecular pathways underlying neuronal protection and autophagy. Moreover, Sirt1 deacetylates proautophagic proteins such as Atg5, Atg7, and Atg8. Echinacoside (ECH) is the main active ingredient of a widely used Chinese herb cistanche, which has been proven to elicit neuroprotective effects in models of neurodegenerative diseases. In this study, we found that ECH could improve PD-like symptoms in MPTP-lesioned mouse model. We further showed that the underlying mechanism of the action of ECH was associated with enhancing autophagy in neurons via bind to Sirt1 directly and affect FoxO expression. Our study demonstrated ECH as a potential therapeutic agent against PD.

Herbal Medicine Formulas for Parkinson's Disease: A Systematic Review and Meta-Analysis of Randomized Double-Blind Placebo-Controlled Clinical Trials

Background: Parkinson's disease (PD) is a debitlitating, chronic, progressive neurodegenerative disorder without modifying therapy. Here, we aimed to evaluate the available evidence of herbal medicine (HM) formulas for patients with PD according to randomized double-blind placebo-controlled clinical trials. Methods: HM formulas for PD were searched in eight main databases from their inception to February 2018. The methodological quality was assessed using Cochrane Collaboration risk of bias tool. Meta-analysis was performed using RevMan 5.3 software. Results: Fourteen trials with Seventeen comparisons comprising 1,311 patients were identified. Compared with placebo groups, HM paratherapy (n = 16 comparisons) showed significant better effects in the assessments of total Unified Parkinson's Disease Rating Scale (UPDRS) (WMD: -5.43, 95% CI:-8.01 to -2.86; P < 0.0001), UPDRS I (WMD: -0.30, 95% CI: -0.54 to -0.06; P = 0.02), UPDRS II (WMD: -2.21, 95% CI: -3.19 to -1.22; P < 0.0001), UPDRS III (WMD: -3.26, 95% CI:-4.36 to -2.16; P < 0.00001), Parkinson's Disease Quality of Life Questionnaire (p < 0.01) and Parkinson's Disease Questionnaire-39 (WMD: -7.65, 95% CI: -11.46 to -3.83; p < 0.0001), Non-motor Symptoms Questionnaire (p < 0.01) and Non-Motor Symptoms Scale (WMD: -9.19, 95% CI: -13.11 to -5.28; P < 0.00001), Parkinson's Disease Sleep Scale (WMD: 10.69, 95% CI: 8.86 to 12.53; P < 0.00001), and Hamilton depression rating scale (WMD: -5.87, 95% CI: -7.06 to -4.68; P < 0.00001). The efficiency of HM monotherapy (n = 1 comparison) was not superior to the placebo according to UPDRS II, UPDRS III and total UPDRS score in PD patients who never received levodopa treatment, all P > 0.05. HM formulas paratherapy were generally safe and well tolerated for PD patients (RR: 0.41, 95% CI: 0.21 to 0.80; P = 0.009). Conclusion: The findings of present study supported the complementary use of HM paratherapy for PD patients, whereas the question on the efficacy of HM monotherapy in alleviating PD symptoms is still open.

From 1H NMR-based non-targeted to LC-MS-based targeted metabolomics strategy for in-depth chemome comparisons among four Cistanche species

The great orthogonality between ¹H NMR spectroscopy and LC-MS implies that their deployments in series could offer an opportunity to gain the qualified molecular markers via comparative metabolomics, and an attempt was made here to propose an integrated strategy namely "from ¹H NMR-based non-targeted to LC-MS-based targeted metabolomics". In-depth chemome comparisons of Cistanche plants, such as C. deserticola, C. salsa, C. tubulosa, and C. sinensis, that possess dramatic economic and ecological benefits for the arid regions in the northwest China attributing to their dramatic medicinal and edible values, were employed to verify the applicability. ¹H NMR-based non-targeted matabolomics acted as the survey experiment to find those signals offering decisive contributions towards the species discrimination, and the signals were translated to a set of putative identities, eighteen ones in total, through matching with authentic compounds and referring to some accessible databases. Afterwards, an advanced LC-MS platform assembling reversed phase liquid chromatography, hydrophilic interaction liquid chromatography, and tailored multiple reaction monitoring, was introduced to simultaneously quantify those eighteen potential markers in a single analytical run, because those candidates exhibited great polarity span as well as wide content range. Significant species differences occurred amongst their chemome patterns. Echinacoside, acteoside, betaine, mannitol, 6-deoxycatalpol, sucrose, and 8-epi-loganic acid were disclosed as the markers enabling the discrimination of those four species. The findings offered an alternative tool to differentiate Cistanche plants. More importantly, the strategy namely "from ¹H NMR-based non-targeted to LC-MS-based targeted metabolomics" facilitates the pursuit of molecular markers among analogue plants, and thereby provides a promising choice for in-depth chemome comparison.

Antidepressant-Like Effects of Cistanche tubulosa Extract on Chronic Unpredictable Stress Rats Through Restoration of Gut Microbiota Homeostasis

Growing evidence shows that neuropsychiatric disorders, such as depression, are linked with gut microbiome through the gut–brain axis. Cistanches Herba is well known for the treatment of “kidney-yang” deficiency in traditional Chinese medicine (TCM), and has been used for treatment of neurodegenerative diseases in recent years. In this study, chronic unpredictable stress (CUS)-induced depression model was established to explore the impact of Cistanche tubulosa extract (CTE) on behavioral tests, monoamine neurotransmitters and neurotrophic factors in hippocampus and colon, gut microbiota composition, and short-chain fatty acids (SCFAs) production. Moreover, correlation analysis was used to evaluate the functional relationship between altered gut microbiota, changed neurotransmitters and neurotrophins in hippocampus and colon, and disturbed concentration of SCFAs. CTE significantly improved depression-like behaviors in rats under CUS. Brain level of 5-hydroxytryptamine (5-HT) and brain-derived neurotrophic factor (BDNF) expression in CUS rats were restored by CTE. The relative abundance of gut microbiota and the concentrations of acetate and hexanoic acid could also be modulated by CTE treatment. We further showed that the application of CTE in CUS rats led to strong correlation among disrupted gut microbiota composition, hippocampus neurotransmitter levels, and production of neuroactive metabolite SCFAs. Altogether, these results identify CTE as a potential treatment for depressive symptoms by restoring homeostasis of gut microbiota for microbiota–gut–brain axis disorders, opening new avenues in the field of neuropsychopharmacology.

Echinacoside suppresses dexamethasone-induced growth inhibition and apoptosis in osteoblastic MC3T3-E1 cells

Glucocorticoids (GCs) are widely used to treat chronic diseases. Prolonged and/or overdose administration of GCs has many side-effects to human health including GC-induced osteoporosis (GIOP). In this investigation, the objective was to assess the influence that echinacoside (ECH) exerts upon dexamethasone-treated murine osteoblastic MC3T3-E1 cells. We found that ECH (5, 10, 20 and 40 mg/l) inhibited dexamethasone (1,000 nM)-suppressed cell viability as demonstrated by Cell Counting Kit-8 (CCK-8) assay. The dose of 10 mg/l was selected for the following experiments because this dose had a better effect than the dose of 5 mg/l, and the doses >10 mg/l had a similar effect as this dose. ECH (10 mg/l) or pifithrin-α (PFT-α) (a p53 inhibitor, 20 µM) suppressed dexamethasone-induced MC3T3-E1 apoptosis as illustrated by Annexin V/propidium iodide (PI) double-labeling flow cytometry analysis. ECH or PFT-α treatment also alleviated dexamethasone's action of inhibiting Bcl-2 expression as well as dexamethasone's action of stimulating on the expression of p53 and Bax. Moreover, lentivirus mediated-p53 overexpression reversed the effects of ECH in dexamethasone-treated MC3T3-E1 cells, suggesting that ECH induced anti-apoptotic effects in dexamethasone-treated osteoblasts via p53-dependent pathway. In summary, ECH has a protective effect against osteoblastic cell apoptosis induced by dexamethasone, suggesting that ECH may have potentials for clinical application in the treatment of GIOP.

Cistanches Herba: An overview of its chemistry, pharmacology, and pharmacokinetics property

ETHNOPHARMACOLOGICAL RELEVANCE

Cistanches Herba is an Orobanchaceae parasitic plant. As a commonly used Traditional Chinese Medicine (TCM), its traditional functions include treating kidney deficiency, impotence, female infertility and senile constipation. Chemical analysis of Cistanches Herba revealed that phenylethanoid glycosides, iridoids, lignans, oligosaccharides, and polysaccharides were the main constituents. Pharmacological studies demonstrated that Cistanches Herba exhibited neuroprotective, immunomodulatory, hormonal balancing, anti-fatigue, anti-inflammatory, hepatoprotection, anti-oxidative, anti-bacterial, anti-viral, and anti-tumor effects, etc. The aim of this review is to provide updated, comprehensive and categorized information on the phytochemistry, pharmacological research and pharmacokinetics studies of the major constituents of Cistanches Herba.

MATERIALS AND METHODS

The literature search was conducted by systematic searching multiple electronic databases including SciFinder, ISI Web of Science, PubMed, Google Scholar and CNKI. Information was also collected from journals, local magazines, books, monographs.

RESULTS

To date, more than 100 compounds have been isolated from this genus, include phenylethanoid glycosides, carbohydrates, lignans, iridoids, etc. The crude extracts and isolated compounds have exhibited a wide range of in vitro and in vivo pharmacologic effects, such as neuroprotective, immunomodulatory, anti-inflammatory, hepatoprotection, anti-oxidative, anti-bacterial, and anti-tumor effects. The phenylethanoid glycosides, echinacoside and acteoside have attracted the most attention for their significantly neuropharmacology effects. Pharmacokinetic studies of echinacoside and acteoside also have also been summarized.

CONCLUSION

Phenylethanoid glycosides have demonstrated wide pharmacological actions and have great clinical value if challenges such as poor bioavailability, fast and extensive metabolism are addressed. Apart from phenylethanoid glycosides, other constituents of Cistanches Herba, their pharmacological activities and underlying mechanisms are also need to be studied further.

Echinacoside, an Inestimable Natural Product in Treatment of Neurological and other Disorders

Echinacoside (ECH), a natural phenylethanoid glycoside, was first isolated from Echinacea angustifolia DC. (Compositae) sixty years ago. It was found to possess numerous pharmacologically beneficial activities for human health, especially the neuroprotective and cardiovascular effects. Although ECH showed promising potential for treatment of Parkinson's and Alzheimer's diseases, some important issues arose. These included the identification of active metabolites as having poor bioavailability in prototype form, the definite molecular signal pathways or targets of ECH with the above effects, and limited reliable clinical trials. Thus, it remains unresolved as to whether scientific research can reasonably make use of this natural compound. A systematic summary and knowledge of future prospects are necessary to facilitate further studies for this natural product. The present review generalizes and analyzes the current knowledge on ECH, including its broad distribution, different preparation technologies, poor pharmacokinetics and kinds of therapeutic uses, and the future perspectives of its potential application.

Herba Cistanches: Anti-aging

The Cistanche species ("Rou Cong Rong" in Chinese) is an endangered wild species growing in arid or semi-arid areas. The dried fleshy stem of Cistanches has been used as a tonic in China for many years. Modern pharmacological studies have since demonstrated that Herba Cistanches possesses broad medicinal functions, especially for use in anti-senescence, anti-oxidation, neuroprotection, anti-inflammation, hepatoprotection, immunomodulation, anti-neoplastic, anti-osteoporosis and the promotion of bone formation. This review summarizes the up-to-date and comprehensive information on Herba Cistanches covering the aspects of the botany, traditional uses, phytochemistry and pharmacology, to lay ground for fully elucidating the potential mechanisms of Herba Cistanches' anti-aging effect and promote its clinical application as an anti-aging herbal medicine.

Multitarget botanical pharmacotherapy in major depression: a toxic brain hypothesis

A significant number of patients with major depression do not respond optimally to current antidepressant drugs. As depression is likely to be a heterogeneous disorder, it is possible that existing neurotransmitter-based antidepressant drugs do not fully address other pathologies that may exist in certain cases. Biological pathologies related to depression that have been proposed and studied extensively include inflammation and immunology, hypercortisolemia, oxidative stress, and impaired angiogenesis. Such pathologies may induce neurodegeneration, which in turn causes cognitive impairment, a symptom increasingly being recognized in depression. A neurotoxic brain hypothesis unifying all these factors may explain the heterogeneity of depression as well as cognitive decline and antidepressant drug resistance in some patients. Compared with neurotransmitter-based antidepressant drugs, many botanical compounds in traditional medicine used for the treatment of depression and its related symptoms have been discovered to be anti-inflammatory, immunoregulatory, anti-infection, antioxidative, and proangiogenic. Some botanical compounds also exert actions on neurotransmission. This multitarget nature of botanical medicine may act through the amelioration of the neurotoxic brain environment in some patients resistant to neurotransmitter-based antidepressant drugs. A multitarget multidimensional approach may be a reasonable solution for patients resistant to neurotransmitter-based antidepressant drugs.

Plants-Derived Neuroprotective Agents: Cutting the Cycle of Cell Death through Multiple Mechanisms

Neuroprotection is the preservation of the structure and function of neurons from insults arising from cellular injuries induced by a variety of agents or neurodegenerative diseases (NDs). The various NDs including Alzheimer's, Parkinson's, and Huntington's diseases as well as amyotropic lateral sclerosis affect millions of people around the world with the main risk factor being advancing age. Each of these diseases affects specific neurons and/or regions in the brain and involves characteristic pathological and molecular features. Hence, several in vitro and in vivo study models specific to each disease have been employed to study NDs with the aim of understanding their underlying mechanisms and identifying new therapeutic strategies. Of the most prevalent drug development efforts employed in the past few decades, mechanisms implicated in the accumulation of protein-based deposits, oxidative stress, neuroinflammation, and certain neurotransmitter deficits such as acetylcholine and dopamine have been scrutinized in great detail. In this review, we presented classical examples of plant-derived neuroprotective agents by highlighting their structural class and specific mechanisms of action. Many of these natural products that have shown therapeutic efficacies appear to be working through the above-mentioned key multiple mechanisms of action.

2',3'-Dideoxycytidine Protects Dopaminergic Neurons in a Mouse Model of Parkinson's Disease

DNA polymerase-β (DNA pol-β) plays a crucial role in the pathogenesis of Parkinson's disease (PD). The aim of this study was to investigate the neuroprotective effects of a DNA polymerase-β inhibitor 2',3'-dideoxycytidine (DDC) in PD models. In the in vitro studies, primary cultured neurons were challenged with 1-methyl-4-phenylpyridinium ion (MPP⁺). The expression of DNA pol-β was assessed using western blot. The neuroprotective effect of DNA pol-β knockdown and DNA pol-β inhibitor DDC was determined using cell viability assay and caspase-3 activity assay. We found that MPP⁺ induced neuronal death and the activation of caspase-3 in a dose-dependent manner. The expression of DNA pol-β increased after the neurons were exposed to MPP⁺. DNA pol-β siRNA or DNA pol-β inhibitor DDC attenuated neuronal death induced by MPP⁺. In the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced mouse model of PD, MPTP treatment triggered behavioral deficits and nigrostriatal lesions. Pretreatment with DDC attenuated MPTP-induced behavioral deficits, dopaminergic neuronal death and striatal dopamine depletion in the MPTP mouse model. These results indicate that DNA pol-β inhibitors may present a novel promising therapeutic option for the neuroprotective treatment of PD.

The 1-Tosylpentan-3-one Protects against 6-Hydroxydopamine-Induced Neurotoxicity

Previous studies have demonstrated that the marine compound austrasulfone, isolated from the soft coral Cladiella australis, exerts a neuroprotective effect. The intermediate product in the synthesis of austrasulfone, dihydroaustrasulfone alcohol, attenuates several inflammatory responses. The present study uses in vitro and in vivo methods to investigate the neuroprotective effect of dihydroaustrasulfone alcohol-modified 1-tosylpentan-3-one (1T3O). Results from in vitro experiments show that 1T3O effectively inhibits 6-hydroxydopamine-induced (6-OHDA-induced) activation of both p38 mitogen-activated protein kinase (MAPK) and caspase-3 in SH-SY5Y cells; and enhances nuclear factor erythroid 2–related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) expression via phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt) signaling. Hoechst staining and Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining results reveal that 1T3O significantly inhibits 6-OHDA-induced apoptosis. In addition, the addition of an Akt or HO-1 inhibitor decreases the protective effect of 1T3O. Thus, we hypothesize that the anti-apoptotic activity of 1T3O in neuronal cells is mediated through the regulation of the Akt and HO-1 signaling pathways. In vivo experiments show that 1T3O can reverse 6-OHDA-induced reduction in locomotor behavior ability in zebrafish larvae, and inhibit 6-OHDA-induced tumor necrosis factor-alpha (TNF-α) increase at the same time. According to our in vitro and in vivo results, we consider that 1T3O exerts its anti-apoptotic activities at SH-SY5Y cells after 6-OHDA challenges, probably via the regulation of anti-oxidative signaling pathways. Therefore, this compound may be a promising therapeutic agent for neurodegenerations.

Jia-Jian-Di-Huang-Yin-Zi decoction reduces apoptosis induced by both mitochondrial and endoplasmic reticulum caspase12 pathways in the mouse model of Parkinson's disease

ETHNOPHARMACOLOGICAL RELEVANCE

As a classical prescription of traditional Chinese medicine (TCM), Jia-Jian-Di-Huang-Yin-Zi decoction (JJDHYZ) has been used to treat the symptoms of neurological disorders with a long history.

AIM OF THE STUDY

To evaluate the effects and possible mechanisms of JJDHYZ on a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced subacute mouse model of Parkinson's disease.

MATERIALS AND METHODS

Adult male C57BL/6 mice were randomly divided into five groups: control, MPTP, JJDHYZ low dosage (JJDHYZ-L, 8.5g/kg/day), medium dosage (JJDHYZ-M, 17g/kg/day) and high dosage (JJDHYZ-H, 34g/kg/day). Behavioral tests, immunohistochemistry, immunofluorescence, and high-performance liquid chromatography (HPLC) were conducted to evaluate the neuroprotective effects of JJDHYZ. The mechanism was further explored using TdT-mediated dUTP nick end labeling staining and transmission electron microscopy. The protein expression of Bax, Bcl-2, cytochrome c, full-length caspase9, cleaved caspase9, cleaved caspase3, caspase12 and C/EBP homologous protein was assessed. The toxicity on hepatocytes and renal cells was detected using the enzyme-linked immunosorbent assay kits.

RESULTS

JJDHYZ-H restored the behavior performance impaired by MPTP, and reduced the loss of tyrosine hydroxylase. Additionally, it blocked the apoptosis, activated cleaved caspase3 and protected the ultrastructural integrity of mitochondria by regulating the expression of proteins in both mitochondrial and endoplasmic reticulum (ER) caspase12 pathways.

CONCLUSIONS

JJDHYZ-H showed behavior recovery and dopamine neuron protection by inhibiting the apoptotic activities associated with mitochondrial and ER caspase12 pathways.

Effect and Mechanism of Chinese Herbal Medicine on Parkinson's Disease

Parkinson's disease is a progressive neurodegenerative disorder. Although both genetic and environmental factors are implicated in the development of Parkinson's disease, the cause of the disease is still unclear. So far conventional treatments to Parkinson's are symptomatic relief and focused mainly on motor symptoms. Chinese herbal medicine has been used to treat many conditions in China, Korea, Japan, and many Southeast Asian countries for 1000 years. During past a few decades, Chinese herbal medicine has gained wider and increasing acceptance within both public and medical profession due to its effectiveness on many conditions in western countries. In this chapter, mechanisms of action of many Chinese herbal compounds/extracts and Chinese herb formulas on the models of Parkinson's were reviewed. Further, reports of effectiveness of Chinese herb formulas on patients with Parkinson's were summarized. It was shown that both Chinese herbal compounds/extracts and herb formulas have either specific target mechanisms of action or multitargets mechanisms of action, as antioxidant, antiinflammatory, and antiapoptosis agents. Clinical studies showed that Chinese herb formulas as an adjunct improved both motor and nonmotor symptoms, and reduced dose of dopaminergic drugs and occurrence of dyskinesia. The evidence from the studies suggests that Chinese herb medicine has potential, acting as neuroprotective to slow down the progression of Parkinson's, and it is able to simultaneously treat both motor and nonmotor symptoms of Parkinson's. More studies are needed to explore the new compounds/extracts derived from Chinese herbs, in particular, their mechanisms of action. It is hopeful that new drugs developed from Chinese herb compounds/extracts and Chinese herb formulas will lead to better and complimentary therapy to PD.

Protective Effects of an Ancient Chinese Kidney-Tonifying Formula against H2O2-Induced Oxidative Damage to MES23.5 Cells

Oxidative damage plays a critical role in the etiology of neurodegenerative disorders including Parkinson's disease (PD). In our study, an ancient Chinese kidney-tonifying formula, which consists of Cistanche, Epimedii, and Polygonatum cirrhifolium, was investigated to protect MES23.5 dopaminergic neurons against hydrogen peroxide- (H₂O₂-) induced oxidative damage. The damage effects of H₂O₂ on MES23.5 cells and the protective effects of KTF against oxidative stress were evaluated using MTT assay, transmission electron microscopy (TEM), immunocytochemistry (ICC), enzyme-linked immunosorbent assay (ELISA), and immunoblotting. The results showed that cell viability was dramatically decreased after a 12 h exposure to 150 μM H₂O₂. TEM observation found that the H₂O₂-treated MES23.5 cells presented cellular organelle damage. However, when cells were incubated with KTF (3.125, 6.25, and 12.5 μg/ml) for 24 h after H₂O₂ exposure, a significant protective effect against H₂O₂-induced damage was observed in MES23.5 cells. Using ICC, we found that KTF inhibited the reduction of the tyrosine hydroxylase (TH) induced by H₂O₂, upregulated the mRNA and protein expression of HO-1, CAT, and GPx-1, and downregulated the expression of caspase 3. These results indicated that KTF may provide neuron protection against H₂O₂-induced cell damage through ameliorating oxidative stress, and our findings provide a new potential strategy for the prevention and treatment of Parkinson's disease.

Echinacoside ameliorates the memory impairment and cholinergic deficit induced by amyloid beta peptides via the inhibition of amyloid deposition and toxicology

This study investigates the role of the amyloid cascade and central neuronal function on the protective effects of echinacoside in amyloid β peptide 1-42 (Aβ 1-42)-treated SH-SY5Y cells and an Aβ 1-42-infused rat.

Neuroprotective Effects of Echinacoside on Regulating the Stress-Active p38MAPK and NF-κB p52 Signals in the Mice Model of Parkinson's Disease

Herbal medicines have long been used to treat Parkinson's disease (PD). To systematically analyze the anti-parkinsonian activity of echinacoside (ECH) in a neurotoxic model of PD and provide a future basis for basic and clinical investigations, male C57BL/6 mice were randomized into blank control, PD model and ECH-administration groups. ECH significantly suppressed the dopaminergic neuron loss (P < 0.01) caused by MPTP and maintained dopamine content (P < 0.01) and dopamine metabolite content (P < 0.05) compared with that measured in mice with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced damage. Additionally, ECH inhibited the activation of microglia and astrocytes in the substantia nigra, which suggested the involvement of neuroinflammation. The relevant cytokines were detected with a Proteome Profiler Array, which confirmed that ECH participated in the regulation of seven cytokines. Given that p38 mitogen-activated protein kinase (p38MAPK) and NF-kappaB (NF-κB) signals are considered to be closely related to neuroninflammation, the gene expression levels of p38MAPK and six NF-κB DNA-binding subunits were assessed. Western blotting analysis showed that both p38MAPK and the NF-κB p52 subunit were upregulated in the MPTP group and that ECH downregulated their expressions. Minocycline was administered as the positive control to inhibit neuroinflammation, and no differences were detected between the minocycline- and ECH-mediated inhibition of the p38MAPK and NF-κB p52 signals. In conclusion, echinacoside is a potential novel orally active compound for regulating neuroinflammation and related signals in Parkinson's disease and may provide a new prospect for clinical treatment.

Cistanches Herba: A Neuropharmacology Review

Cistanches Herba (family Orobanchaceae), commonly known as “desert ginseng” or Rou Cong Rong, is a global genus and commonly used for its neuroprotective, immunomodulatory, anti-oxidative, kidney impotence, laxative, anti-inflammatory, hepatoprotective, anti-bacterial, anti-viral, and anti-tumor effects in traditional herbal formulations in North Africa, Arabic, and Asian countries. The major bioactive compound present in this plant is phenylethanoid glycosides. In recent years, there has been great important in scientific investigation of the neuropharmacological effects of the bioactive compounds. The in vitro and in vivo studies suggests these compounds demonstrate neuropharmacological activities against a wide range of complex nervous system diseases which occurs through different mechanisms include improving immunity function and kidney aging, anti-lipid peroxidation, scavenging free radical, inducing the activation of caspase-3 and caspase-8. This review aims to summaries the various neuropharmacological effects and mechanisms of Cistanches Herba extracts and related compounds, including its efficacy as a cure for Alzheimer’s disease and Parkinson’s disease with reference to the published literature. Which provides guidance for further research on the clinical application of Cistanches Herba.

Rapid screening and identification of the differences between metabolites of Cistanche deserticola and C. tubulosa water extract in rats by UPLC-Q-TOF-MS combined pattern recognition analysis

Cistanches Herba is a famous traditional Chinese medicine that has been in use for treating kidney deficiency, impotence, female infertility, morbid leucorrhea, profuse metrorrhagia, and senile constipation. With the exception of studies available for a few single active ingredients such as echinacoside, acteoside, and poliumoside, comprehensive and systematic studies on in vivo metabolism of Cistanches Herba are lacking despite its widespread clinical application. There is no comparative study yet on the metabolites resulting from the traditional usage of Cistanche deserticola and C. tubulosa water extract - two species that are recorded in Chinese Pharmacopoeia. This further restricts research on the therapeutic effect of Cistanches Herba to a great extent. In this study, a robust and unbiased UPLC-Q-TOF-MS combined pattern recognition analysis (orthogonal partial least squared discriminant analysis, OPLS-DA) was employed to rapidly screen prototype components and metabolites of C. deserticola and C. tubulosa water extract in rat urine, feces, and serum. A total of 71 metabolites from C. deserticola including 25 prototype components and 46 metabolites, and 45 metabolites from C. tubulosa including 18 prototype components and 27 metabolites were tentatively identified. Out of these, 10 metabolites were characterized for the first time in these two species. Results of this study indicate that phenylethanoid glycosides (PhGs) are mainly metabolized into degradation products in the gastrointestinal tract of rats. The chemical components cistanoside B, C, D, and E exist only in C. deserticola and release methylated hydroxytyrosol (HT) following metabolism. This factor contributes to the difference between metabolites of C. deserticola and C. tubulosa water extract in rats and is responsible for the differential therapeutic effect that these two species of Cistanches Herba have on the same diseases.

Neuroprotective Effects of a Standardized Flavonoid Extract from Safflower against a Rotenone-Induced Rat Model of Parkinson's Disease

Parkinson’s disease (PD) is a major age-related neurodegenerative disorder characterized by the loss of dopaminergic neurons in the substantia nigra par compacta (SNpc). Rotenone is a neurotoxin that is routinely used to model PD to aid in understanding the mechanisms of neuronal death. Safflower (Carthamus tinctorius. L.) has long been used to treat cerebrovascular diseases in China. This plant contains flavonoids, which have been reported to be effective in models of neurodegenerative disease. We previously reported that kaempferol derivatives from safflower could bind DJ-1, a protein associated with PD, and that a flavonoid extract from safflower exhibited neuroprotective effects in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-induced mouse model of PD. In this study, a standardized safflower flavonoid extract (SAFE) was isolated from safflower and found to primarily contain flavonoids. The aim of the current study was to confirm the neuroprotective effects of SAFE in rotenone-induced Parkinson rats. The results showed that SAFE treatment increased body weight and improved rearing behavior and grip strength. SAFE (35 or 70 mg/kg/day) treatment reversed the decreased protein expression of tyrosine hydroxylase, dopamine transporter and DJ-1 and increased the levels of dopamine and its metabolite. In contrast, acetylcholine levels were decreased. SAFE treatment also led to partial inhibition of PD-associated changes in extracellular space diffusion parameters. These changes were detected using a magnetic resonance imaging (MRI) tracer-based method, which provides novel information regarding neuronal loss and astrocyte activation. Thus, our results indicate that SAFE represents a potential therapeutic herbal treatment for PD.

Phytochemicals as future drugs for Parkinson’s disease: a comprehensive review

Parkinson’s disease (PD) is the second most common chronic neurodegenerative disease that affects motor skills and cognitive performance. The conventional therapeutic approaches for the management of PD are just able to alleviate symptoms. Exploring for achieving novel substances with therapeutic benefits in PD patients is the focus of a wide range of current investigations. The aim of the present study is to comprehensively review phytochemicals with protective or therapeutic activities in PD and focus on their neuropsychopharmacological mechanisms. Various subgroups of polyphenols (flavonoids, phenolic acids, stilbenes, and lignanes) and terpenes are the most abundant groups of phytochemicals with well-established antiparkinsonian effects. Other phytochemical categories, such as alkaloids, cinnamates, carbohydrates, amino acids, and fatty acid amides, also have some representatives with positive effects in PD. Phytochemicals perform their antiparkinsonian effect through several mechanisms of action, including suppressing apoptosis (via the reduction of Bax/Bcl-2, caspase-3, -8, and -9, and α-synuclein accumulation), decreasing dopaminergic neuronal loss and dopamine depletion, reducing the expression of proinflammatory cytokines (such as prostaglandin E2, interleukin-6, interleukin-1β, and nuclear factor-κB), and modulating nuclear and cellular inflammatory signaling, elevation of neurotrophic factors, and improvement of antioxidant status. Plant-derived natural products can be considered as future pharmaceutical drugs or adjuvant treatment with conventional therapeutic approaches to improve their efficacy and alleviate their psychological adverse effects in the management of PD. Well-designed clinical trials are mandatory to evaluate the protective and healing benefits of phytochemicals as promising future drugs in the management of neurodegenerative diseases.

Phenylethanoid Glycosides: Research Advances in Their Phytochemistry, Pharmacological Activity and Pharmacokinetics

Phenylethanoid glycosides (PhGs) are widely distributed in traditional Chinese medicines as well as in other medicinal plants, and they were characterized by a phenethyl alcohol (C₆-C₂) moiety attached to a β-glucopyranose/β-allopyranose via a glycosidic bond. The outstanding activity of PhGs in diverse diseases proves their importance in medicinal chemistry research. This review summarizes new findings on PhGs over the past 10 years, concerning the new structures, their bioactivities, including neuroprotective, anti-inflammatory, antioxidant, antibacterial and antivirus, cytotoxic, immunomodulatory, and enzyme inhibitory effects, and pharmacokinetic properties.

Echinacoside Protects Against MPP(+)-Induced Neuronal Apoptosis via ROS/ATF3/CHOP Pathway Regulation

Echinacoside (ECH) is protective in a mouse model of Parkinson's disease (PD) induced by 1-methyl-4-phenylpyridinium ion (MPP(+)). To investigate the mechanisms involved, SH-SY5Y neuroblastoma cells were treated with MPP(+) or a combination of MPP(+) and ECH, and the expression of ATF3 (activating transcription factor 3), CHOP (C/EBP-homologous protein), SCNA (synuclein alpha), and GDNF (glial cell line-derived neurotrophic factor) was assessed. The results showed that ECH significantly improved cell survival by inhibiting the generation of MPP(+)-induced reactive oxygen species (ROS). In addition, ECH suppressed the ROS and MPP(+)-induced expression of apoptotic genes (ATF3, CHOP, and SCNA). ECH markedly decreased the MPP(+)-induced caspase-3 activity in a dose-dependent manner. ATF3-knockdown also decreased the CHOP and cleaved caspase-3 levels and inhibited the apoptosis induced by MPP(+). Interestingly, ECH partially restored the GDNF expression that was down-regulated by MPP(+). ECH also improved dopaminergic neuron survival during MPP(+) treatment and protected these neurons against the apoptosis induced by MPTP. Taken together, these data suggest that the ROS/ATF3/CHOP pathway plays a critical role in mechanisms by which ECH protects against MPP(+)-induced apoptosis in PD.