Protective Effects of Streblus asper Leaf Extract on H2O2-Induced ROS in SK-N-SH Cells and MPTP-Induced Parkinson's Disease-Like Symptoms in C57BL/6 Mouse

Effects of polyphenol on motor function in mice with Parkinson's disease: a systematic review and meta-analysis

Polyphenols have been reported to have a multi-targeted neuroprotective effect on Parkinson's disease (PD). However, there has been no comprehensive analysis of the effect of polyphenol therapy on improving motor symptoms in PD. We used keywords to search the electronic databases PubMed, Scopus, EBSCO, SpringerLink, China National Knowledge Infrastructure (CNKI), Wan Fang and Web of Science from the establishment of the database to April 2023. A randomized effects model systematic review and meta-analysis of 83 included studies were conducted to investigate the ameliorative effects of polyphenols on 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced motor dysfunction in a rodent model of PD. The results showed that compared with PD control group, polyphenols significantly improved balance, exploration, vertical crawling, horizontal crawling, muscle strength and sensorimotor function motor dysfunction of rodents. Subgroup analysis showed that the types of polyphenols had different recovery effects on motor symptoms of PD. Oral polyphenol intervention was superior to intraperitoneal and intravenous administration. This meta-analysis provides comprehensive evidence for the prevention or treatment of Parkinson's motor symptoms with polyphenols and expands the idea of future clinical application of polyphenols.

Effect of Streblus asper Leaf Extract on Scopolamine-Induced Memory Deficits in Zebrafish: The Model of Alzheimer's Disease

Streblus asper (SA) is well known as a folk medicinal plant in Asian countries. The effect of SA extract on preventing memory impairment in zebrafish induced by scopolamine was investigated. Male zebrafish, Danio rerio, were divided into 6 groups including the control, scopolamine 200 μM (SCO), scopolamine plus rivastigmine 1.5 mg/kg (RV + SCO), and scopolamine plus SA extract at doses of 200, 400, and 800 mg/kg (SA200 + SCO, S400 + SCO, and SA800 + SCO), respectively. Spatial memory was evaluated by the colour-biased appetite conditioning T-maze test, while fear memory was measured by the inhibitory avoidance test. In the spatial memory test, results showed that the RV + SCO group had the best time spent ratio in the T-maze, followed by SA800 + SCO, SA400 + SCO, SA200 + SCO, control, and SCO group, respectively, but with no statistical significance. For the fear memory test, zebrafish that received SA at doses of 200, 400, and 800 mg/kg had significantly increased latency time as 21.75 ± 4.59, 23.75 ± 13.01, and 18.20 ± 18.84 min, respectively, when compared to the SCO group (9.80 ± 10.45 min). These results suggested that SA extract attenuated memory impairment in an inhibitory avoidance test related to fear memory. Our findings can be useful for further research to develop SA extract as a health product to ameliorate the symptoms of Alzheimer's disease.

Balance alterations and reduction of pedunculopontine cholinergic neurons in early stages of parkinsonism in middle-aged rats

The purpose of the present study was to investigate balance alterations and the possible role of the cholinergic neurons in the pedunculopontine nucleus (PPN) in the early stages of a progressive animal model of Parkinson's disease (PD). Twenty-eight middle-aged (8-9 months) male Wistar rats received 4 or 10 subcutaneous vehicle (control, CTL) or reserpine (RES) injections (0.1 mg/kg). The animals were submitted to different behavioral tests. Forty-eight hours after the 4th injection, half of the animals of each group (n = 7) were perfused and submitted to immunohistochemical analysis for tyrosine hydroxylase (TH) and choline acetyltransferase (ChAT). The remaining animals (n = 7 per group) were killed 48 h after the 10th injection. RES group presented motor deficits in the catalepsy and open field tests starting at days 12 and 20 of treatment, respectively (only for the animals that received 10 injections). On the other hand, dynamic and static balance changes were observed at earlier stages of RES treatment, starting at days 6 and 4, respectively. At this point of the treatment, there was no decrease in the number of TH immunoreactivity neurons in the substantia nigra pars compacta (SNpc), ventral tegmental area (VTA) and dorsal striatum (DS). However, a decrease was observed in SNpc and dorsal striatum of animals that received 10 injections. In contrast, there was a decrease in the number of ChAT immunoreactive cells in PPN concomitantly to the balance alterations at the early stages of treatment (after 4 RES injections). Thus, by mimicking the progressiveness of PD, the reserpine model made it possible to identify static and dynamic balance impairments prior to the motor alterations in the catalepsy and open field tests. In addition, changes in balance were accompanied by a reduction in the number of ChAT immunoreactive cells in NPP in the early stages of treatment.

Antilipoxygenase and Anti-Inflammatory Activities of Streblus asper Leaf Extract on Xylene-Induced Ear Edema in Mice

Streblus asper (SA) belonging to the Moraceae family is well known as a folk medicinal plant in Asian countries. This study aimed to investigate the antilipoxygenase activity and the anti-inflammatory effects of the SA leaf extract. An in vitro antilipoxygenase study was performed using a lipoxygenase assay, and the oxidation of linoleic acid into 13-hydroperoxy linoleic acid (HPODE) was detected with a UV spectrophotometer at a wavelength of 234 nm. In the animal study, twenty-five male ICR mice were induced as ear edema by topical xylene, and the ear thickness of the mice was measured. The lipoxygenase assay results showed that the IC50 values of diclofenac sodium and SA were 0.0015 and 37.96 μg/mL, respectively. In the animal study, mice that received diclofenac sodium exhibited significantly reduced ear edema induced by xylene from 30 min onward, while mice that received 250 mg/kg and 500 mg/kg SA exhibited significantly reduced ear edema compared with the control group 45 min after induction with xylene. These results suggested that the SA leaf extract had anti-inflammatory activity. However, further studies are required to evaluate these effects and the additional potential of the plant that might be beneficial for the development of pharmaceutical products that prevent and treat inflammation.

Protective Effect of Compound Formula Rehmannia against Neurotoxicity and Apoptosis Induced by α-Syn in In Vivo and In Vitro Models of Parkinson's Disease

The present study aimed to investigate the protective effect of compound formula Rehmannia (CFR) against the development of Parkinson's disease (PD). After the in vivo and in vitro models of PD were established with overexpression α-syn induced, CFR was administrated into the PD model rats for 6 weeks or SK-N-SH cells with coincubation for 48 h. Apomorphine-induced rotation test, CCK8 assay, TUNEL assay, immunofluorescence staining, and western blot assay were performed to evaluate the behavioral changes, cell viability, cell apoptosis, α-syn, GSK-3β, P-GSK-3β (Ser9), P-GSK-3β (Tyr216), and β-catenin expression in PD rats or SK-N-SH cells. PD rat behavior results showed that the rotation numbers were significantly decreased in the CFR treatment group comparing with the AAV-α-syn PD model group. The cell viability suppressed by H₂O₂ and α-syn in SK-N-SH model cells was also significantly improved with CFR administration. Cell apoptosis and α-syn overexpression observed in PD rats and SK-N-SH cells were also inhibited by CFR treatment. Furthermore, the protein expression of α-syn, GSK-3β, P-GSK-3β (Ser9), P-GSK-3β (Tyr216), and β-catenin in in vivo and in vitro was also significantly regulated by CFR. The present study suggested that CFR may be considered as a potential neuroprotective agent against PD, and this application will require further investigation.

Potential Thai medicinal plants for neurodegenerative diseases: A review focusing on the anti-glutamate toxicity effect

Neurodegenerative diseases (NDD) are a range of debilitating conditions of the brain involving progressive loss of neurons, many of which are still currently incurable despite enormous efforts on drug discovery and development in the past decade. As NDD is closely linked to old age, the rapid worldwide growth in the aging population contributes to an increasing number of people with one of these incurable diseases and therefore it is considered a significant global health issue. There is an urgent need for novel effective treatments for NDD, and many new research strategies are centered on traditional medicine as an alternative or complementary solution. Several previous findings have suggested that glutamate toxicity drives neurodegeneration in many NDD, and the medicinal plants with anti-glutamate toxicity properties can be potentially used for their treatment. In order to obtain data relating to natural products against glutamate toxicity, six candidate plant species of Thailand were identified. Studies utilizing these herbs were searched for using the herb name (Latin and common names) along with the term "glutamate" in the following databases across all available years: PubMed, Scopus, and Google Scholar. This review emphasizes the importance of glutamate toxicity in NDD and summarizes individual plants and their active constituents with the mechanism of action against glutamate toxicity-mediated neuronal cell death that could be a promising resource for future NDD therapy.

TAXONOMY CLASSIFICATION BY EVISE

Alzheimer's disease, Neurodegenerative diseases, Cell culture, Molecular Biology, Traditional herbal medicine, Oxidative stress, Glutamate neurotransmitter.

Carvacrol Protects Against 6-Hydroxydopamine-Induced Neurotoxicity in In Vivo and In Vitro Models of Parkinson's Disease

Parkinson's disease (PD) is a progressive neurodegenerative movement disorder characterized by selective loss of dopaminergic neurons that project from the substantia nigra pars compacta to the striatum. Evidence from human and animal studies has suggested that oxidative damage critically contributes to neuronal loss in PD. Carvacrol (CAR), a monoterpenic phenol, is the main constituents in the essential oil of many aromatic plants and possesses some properties including anti-inflammatory and anti-oxidant effects. In this study, in vitro and in vivo experiments were performed with the CAR in order to investigate its potential neuroprotective effects in models of PD. Post-treatment with CAR in vitro was found to protect rat adrenal pheochromocytoma PC12 cells from toxicity induced by 6-hydroxydopamine (6-OHDA) administration in a dose-dependent manner by (1) increasing cell viability and (2) reduction in intracellular reactive oxygen species, intracellular lipid peroxidation, and annexin-positive cells. In vivo, post-treatment with CAR (15 and 20 mg/kg) was protective against neurodegenerative phenotypes associated with systemic administration of 6-OHDA. Results indicated that CAR improved the locomotor activity, catalepsy, akinesia, bradykinesia, and motor coordination and reduced the apomorphine-caused rotation in 6-OHDA-stimulated rats. Increased level of reduced glutathione content and a decreased level of MDA (malondialdehyde) were observed in the 6-OHDA rats post-treated with CAR. These findings suggest that CAR exerts protective effects, possibly related to an anti-oxidation mechanism, in these in vitro and in vivo models of Parkinson's disease.

Oxidative stress induced by carboplatin promotes apoptosis and inhibits migration of HN-3 cells

Laryngeal squamous cell carcinoma (LSCC) is currently a serious public health problem in China; thus, it is urgent to identify effective treatment strategies for this disease. Previous studies demonstrated that reactive oxygen species (ROS) serve important roles in the apoptosis of LSCC cells. It has also been indicated that carboplatin (CBDCA), a second-generation platinum compound with broad antineoplastic properties, is able to induce oxidative stress to produce ROS, which in turn promotes apoptosis. Thus, the present study investigated if CBDCA is cytotoxic in LSCC cells due to the oxidative stress caused by ROS. Therefore, an MTT assay was performed to determine the cell viability of HN-3 LSCC cells following treatment with different doses of CBDCA. Subsequently, the expression levels of ROS and the rate of apoptosis/necrosis were evaluated in the cells. Following this, the HN-3 cells were co-treated with CBDCA and glutathione (GSH) or H₂O2, followed by an MTT assay, a cell migration assay and western blot analysis. The results demonstrated that CBDCA reduced the viability of HN-3 cells in a time- and dose-dependent manner and promoted the production of ROS and apoptosis at certain doses. Additionally, the combination treatment of CBDCA and H2O2 enhanced the inhibitory effects of CBDCA on cell viability and migration ability, and promoted apoptosis in HN-3 cells; whereas the combined treatment of CBDCA and GSH exerted opposite effects. The results of the present study demonstrated that CBDCA promotes the apoptosis of HN-3 cells through accumulation of ROS, which may provide a novel treatment strategy for treating LSCC.

Acid-base fractions separated from Streblus asper leaf ethanolic extract exhibited antibacterial, antioxidant, anti-acetylcholinesterase, and neuroprotective activities

BACKGROUND

Streblus asper is a well-known plant native to Southeast Asia. Different parts of the plant have been traditionally used for various medicinal purposes. However, there is very little scientific evidence reporting its therapeutic benefits for potential treatment of Alzheimer's disease (AD). The study aimed to evaluate antibacterial, antioxidant, acetylcholinesterase (AChE) inhibition, and neuroprotective properties of S. asper leaf extracts with the primary objective of enhancing therapeutic applications and facilitating activity-guided isolation of the active chemical constituents.

METHODS

The leaves of S. asper were extracted in ethanol and subsequently fractionated into neutral, acid and base fractions. The phytochemical constituents of each fraction were analyzed using GC-MS. The antibacterial activity was evaluated using a broth microdilution method. The antioxidant activity was determined using DPPH and ABTS radical scavenging assays. The neuroprotective activity against glutamate-induced toxicity was tested on hippocampal neuronal HT22 cell line by evaluating the cell viability using MTT assay. The AChE inhibitory activity was screened by thin-layer chromatography (TLC) bioautographic method.

RESULTS

The partition of the S. asper ethanolic leaf extract yielded the highest mass of phytochemical constitutions in the neutral fraction and the lowest in the basic fraction. Amongst the three fractions, the acidic fraction showed the strongest antibacterial activity against gram-positive bacteria. The antioxidant activities of three fractions were found in the order of acidic > basic > neutral, whereas the decreasing order of neuroprotective activity was neutral > basic > acidic. TLC bioautography revealed one component in the neutral fraction exhibited anti-AChE activity. While in the acid fraction, two components showed inhibitory activity against AChE. GC-MS analysis of three fractions showed the presence of major phytochemical constituents including terpenoids, steroids, phenolics, fatty acids, and lipidic plant hormone.

CONCLUSIONS

Our findings have demonstrated the therapeutic potential of three fractions extracted from S. asper leaves as a promising natural source for neuroprotective agents with additional actions of antibacterials and antioxidants, along with AChE inhibitors that will benefit in the development of new natural compounds in therapies against AD.

Ethanolic extract of Streblus asper leaves protects against glutamate-induced toxicity in HT22 hippocampal neuronal cells and extends lifespan of Caenorhabditis elegans

Background

Although such local herb as Streblus asper (family Moraceae) has long been recognized for traditional folk medicines and important ingredient of traditional longevity formula, its anti-neurodegeneration or anti-aging activity is little known. This study aimed to investigate the neuroprotective effect of S. asper leaf extracts (SA-EE) against toxicity of glutamate-mediated oxidative stress, a crucial factor contributing to the neuronal loss in age-associated neurodegenerative diseases and the underlying mechanism as well as to evaluate its longevity effect.

Methods

Using mouse hippocampal HT22 as a model for glutamate oxidative toxicity, we carried out MTT and LDH assays including Annexin V-FITC/propidium iodide staining to determine the SA-EE effect against glutamate-induced cell death. Antioxidant activities of SA-EE were evaluated using the radical scavenging and DCFH-DA assays. To elucidate the underlying mechanisms, SA-EE treated cells were analyzed for the expressions of mRNA and proteins interested by immunofluorescent staining, western blot analysis and quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR) techniques. The longevity effect of SA-EE was examined on C. elegans by lifespan assay.

Results

We demonstrate that a concentration-dependent reduction of glutamate-induced cytotoxicity was significant after SA-EE treatment as measured by MTT and LDH assays. Annexin V-FITC/propidium iodide and immunofluorescent staining showed that co-treatment of glutamate with SA-EE significantly reduced apoptotic-inducing factor (AIF)-dependent apoptotic cell death. DCFH-DA assay revealed that this extract was capable of dose dependently attenuating the ROS caused by glutamate. Western blot analysis and qRT-PCR showed that nuclear factor erythroid 2-related factor 2 (Nrf2) protein levels in the nucleus, as well as mRNA levels of antioxidant-related genes under Nrf2 regulation were significantly increased by SA-EE. Furthermore, this extract was capable of extending the lifespan of C. elegans.

Conclusions

SA-EE possesses both longevity effects and neuroprotective activity against glutamate-induced cell death, supporting its therapeutic potential for the treatment of age-associated neurodegenerative diseases.

Effects of mild running on substantia nigra during early neurodegeneration

Moderate physical exercise acts at molecular and behavioural levels, such as interfering in neuroplasticity, cell death, neurogenesis, cognition and motor functions. Therefore, the aim of this study is to analyse the cellular effects of moderate treadmill running upon substantia nigra during early neurodegeneration. Aged male Lewis rats (9-month-old) were exposed to rotenone 1mg/kg/day (8 weeks) and 6 weeks of moderate treadmill running, beginning 4 weeks after rotenone exposure. Substantia nigra was extracted and submitted to proteasome and antioxidant enzymes activities, hydrogen peroxide levels and Western blot to evaluate tyrosine hydroxylase (TH), alpha-synuclein, Tom-20, PINK1, TrkB, SLP1, CRMP-2, Rab-27b, LC3II and Beclin-1 level. It was demonstrated that moderate treadmill running, practiced during early neurodegeneration, prevented the increase of alpha-synuclein and maintained the levels of TH unaltered in substantia nigra of aged rats. Physical exercise also stimulated autophagy and prevented impairment of mitophagy, but decreased proteasome activity in rotenone-exposed aged rats. Physical activity also prevented H₂O₂ increase during early neurodegeneration, although the involved mechanism remains to be elucidated. TrkB levels and its anterograde trafficking seem not to be influenced by moderate treadmill running. In conclusion, moderate physical training could prevent early neurodegeneration in substantia nigra through the improvement of autophagy and mitophagy.

Treatment of steroid-induced osteonecrosis of the femoral head using porous Se@SiO2 nanocomposites to suppress reactive oxygen species

Reducing oxidative stress (ROS) have been demonstrated effective for steroid-induced osteonecrosis of the femoral head (steroid-induced ONFH). Selenium (Se) plays an important role in suppressing oxidative stress and has huge potential in ONFH treatments. However the Se has a narrow margin between beneficial and toxic effects which make it hard for therapy use in vivo. In order to make the deficiency up, a control release of Se (Se@SiO₂) were realized by nanotechnology modification. Porous Se@SiO₂ nanocomposites have favorable biocompatibility and can reduced the ROS damage effectively. In vitro, the cck-8 analysis, terminal dexynucleotidyl transferase (TdT)-mediated dUTP nick end labeling (TUNEL) stain and flow cytometry analysis showed rare negative influence by porous Se@SiO₂ nanocomposites but significantly protective effect against H₂O₂ by reducing ROS level (detected by DCFH-DA). In vivo, the biosafety of porous Se@SiO₂ nanocomposites were confirmed by the serum biochemistry, the ROS level in serum were significantly reduced and the curative effect were confirmed by Micro CT scan, serum Elisa assay (inflammatory factors), Western blotting (quantitative measurement of ONFH) and HE staining. It is expected that the porous Se@SiO₂ nanocomposites may prevent steroid-induced ONFH by reducing oxidative stress.