Tetramethylpyrazine Improves Cognitive Impairment and Modifies the Hippocampal Proteome in Two Mouse Models of Alzheimer's Disease.

Alzheimer's disease (AD), one of the most common neurodegenerative diseases, has no effective treatment. We studied the potential effects of tetramethylpyrazine (TMP), an alkaloid in the rhizome of Ligusticum chuanxiong Hort. used in Traditional Chinese Medicine (chuanxiong) to treat ischemic stroke, on AD progression in two AD mouse models. Eight-month-old 3xTg-AD mice received TMP treatment (10 mg/kg/d) for 1 month, and 4-month-old APP/PS1-AD mice received TMP treatment (10 mg/kg/d) for 2 months. Behavioral tests, including step-down passive avoidance (SDA), new object recognition (NOR), Morris water maze (MWM), and Contextual fear conditioning test showed that TMP significantly improved the learning and memory of the two AD-transgenic mice. In addition, TMP reduced beta-amyloid (Aß) levels and tau phosphorylation (p-tau). Venny map pointed out that 116 proteins were commonly changed in 3xTg mice vs. wild type (WT) mice and TMP-treated mice vs. -untreated mice. The same 130 proteins were commonly changed in APP/PS1 mice vs. WT mice and TMP-treated mice vs. -untreated mice. The functions of the common proteins modified by TMP in the two models were mainly involved in mitochondrial, synaptic, cytoskeleton, ATP binding, and GTP binding. Mitochondrial omics analysis revealed 21 and 20 differentially expressed mitochondrial proteins modified by TMP in 3xTg-AD mice and APP/PS1 mice, respectively. These differential proteins were located in the mitochondrial inner membrane, mitochondrial outer membrane, mitochondrial gap, and mitochondrial matrix, and the function of some proteins is closely related to oxidative phosphorylation (OXPHOS). Western-blot analysis confirmed that TMP changed the expression of OXPHOS complex proteins (sdhb, ndufa10, uqcrfs1, cox5b, atp5a) in the hippocampus of the two AD mice. Taken together, we demonstrated that TMP treatment changed the hippocampal proteome, reduced AD pathology, and reduced cognitive impairment in the two AD models. The changes might be associated with modification of the mitochondrial protein profile by TMP. The results of the study suggest that TMP can improve the symptoms of AD.

TBN improves motor function and prolongs survival in a TDP-43M337V mouse model of ALS.

Amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration (FTLD) are serious neurodegenerative diseases. Although their pathogenesis is unclear, the abnormal accumulation of TAR DNA-binding protein of 43 kDa (TDP-43) is a pathological feature that exists in almost all patients. Thus far, there is no drug that can cure ALS/FTLD. Tetramethylpyrazine nitrone (TBN) is a derivative of tetramethylapyrazine, derived from the traditional Chinese medicine Ligusticum chuanxiong, which has been widely proven to have therapeutic effects on models of various neurodegenerative diseases. TBN is currently under clinical investigation for several indications including a Phase II trial of ALS. Here, we explored the therapeutic effect of TBN in an ALS/FTLD mouse model. We injected the TDP-43 M337V virus into the striatum of mice unilaterally and bilaterally, and then administered 30 mg/kg TBN intragastrically to observe changes in behavior and survival rate of mice. The results showed that in mice with unilateral injection of TDP-43M337V into the striatum, TBN improved motor deficits and cognitive impairment in the early stages of disease progression. In mice with bilateral injection of TDP-43M337V into the striatum, TBN not only improved motor function but also prolonged survival rate. Moreover, we show that its therapeutic effect may be through activation of the Akt/mTOR/GSK-3ß and AMPK/PGC-1α/Nrf2 signaling pathways. In summary, TBN is a promising agent for the treatment of ALS/FTLD.

The Tetramethylpyrazine Analogue T-006 Alleviates Cognitive Deficits by Inhibition of Tau Expression and Phosphorylation in Transgenic Mice Modeling Alzheimer's Disease.

T-006, a small-molecule compound derived from tetramethylpyrazine (TMP), has potential for the treatment of neurological diseases. In order to investigate the effect of T-006 prophylactic treatment on an Alzheimer's disease (AD) model and identify the target of T-006, we intragastrically administered T-006 (3 mg/kg) to Alzheimer's disease (AD) transgenic mice (APP/PS1-2xTg and APP/PS1/Tau-3xTg) for 6 and 8 months, respectively. T-006 improved cognitive ability after long-term administration in two AD mouse models and targeted mitochondrial-related protein alpha-F1-ATP synthase (ATP5A). T-006 significantly reduced the expression of phosphorylated-tau, total tau, and APP while increasing the expression of synapse-associated proteins in 3xTg mice. In addition, T-006 modulated the JNK and mTOR-ULK1 pathways to reduce both p-tau and total tau levels. Our data suggested that T-006 mitigated cognitive decline primarily by reducing the p-tau and total tau levels in 3xTg mice, supporting further investigation into its development as a candidate drug for AD treatment.

Dextran sulfate sodium-induced colitis and ginseng intervention altered oral pharmacokinetics of cyclosporine A in rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Application of cyclosporine A (CsA) as a rescue treatment in acute severe ulcerative colitis (UC) is limited by its narrow therapeutic window and great interpatient variability. As a substrate of cytochrome P450 3A enzyme (CYP3A) and P-glycoprotein (P-gp), the oral pharmacokinetics of CsA is susceptible to disease status and concomitant medications. Combined treatment with ginseng, a famous medicinal herb frequently prescribed for ameliorating abnormal immune response in many diseases including UC, showed immunologic safety in CsA-based immunosuppression. AIM OF THE STUDY: Since the therapeutic levels of CsA can be achieved within 24 h, this study first assessed the impact of acute colitis and ginseng intervention on the single oral dose pharmacokinetics of CsA and explored the underlying mechanisms in dextran sulfate sodium (DSS)-induced colitis rats and Caco-2 cells. MATERIALS AND METHODS: Rats received drinking water (normal group), 5% DSS (UC group), or 5% DSS plus daily oral ginseng extract (GS+UC group). On day 7, GS+UC group only received an oral dose of CsA (5 mg/kg), while animals of normal or UC group received an oral, intravenous (1.25 mg/kg), or intraperitoneal dose of CsA (1.25 mg/kg), respectively. Blood, liver/intestine tissues and fecal samples were collected for determining CsA and main hydroxylated metabolite HO-CsA or measuring hepatic/intestinal CYP3A activity. Caco-2 cells were incubated with gut microbial culture supernatant (CS) of different groups or ginseng (decoction or polysaccharides), and then CYP3A, P-gp and tight junction (TJ) proteins were determined. RESULTS: Oral CsA exhibited enhanced absorption, systemic exposure and tissue accumulation, and lower fecal excretion, while intravenous or intraperitoneal CsA showed lower systemic exposure and enhanced distribution, in colitis rats. Diminished intestinal and hepatic P-gp expression well explained the changes with DSS-induced colitis. Moreover, blood exposures of HO-CsA in both normal and colitis after oral dosing were significantly higher than intravenous/intraperitoneal dosing, supporting the dominant role of intestinal first-pass metabolism. Interestingly, colitis reduced CYP3A expression in intestine and liver but only potentiated intestinal CYP3A activity, causing higher oral systemic exposure of HO-CsA. Oral ginseng mitigated colitis-induced down-regulation of CYP3A and P-gp expression, facilitated HO-CsA production, biliary excretion and colonic sequestration of CsA, while not affected CsA oral systemic exposure. In Caco-2 cells, gut microbial CS from both colitis and GS+UC group diminished P-gp function, while ginseng polysaccharides directly affected ZO-1 distribution and suppressed TJ proteins expression, explaining unaltered oral CsA systemic exposure. CONCLUSIONS: DSS-induced colitis significantly altered oral CsA disposition through regulating intestinal and hepatic P-gp and CYP3A. One-week ginseng treatment enhanced colonic accumulation while not altered the systemic exposure of CsA after single oral dosing, indicating pharmacokinetic compatibility between the two medications.

Transcription factor EB agonists from natural products for treating human diseases with impaired autophagy-lysosome pathway.

Autophagy is a highly conserved degradation process for long-lived intracellular proteins and organelles mediated by lysosomes. Deficits in the autophagy-lysosome pathway (ALP) have been linked to a variety of human diseases, including neurodegenerative diseases, lysosomal storage disorders, and cancers. Transcription factor EB (TFEB) has been identified as a major regulator of autophagy and lysosomal biogenesis. Increasing evidence has demonstrated that TFEB activation can promote the clearance of toxic protein aggregates and regulate cellular metabolism. Traditional Chinese medicine (TCM)-derived natural products as important sources for drug discovery have been widely used for the treatment of various diseases associated with ALP dysfunction. Herein, we review (1) the regulation of TFEB and ALP; (2) TFEB and ALP dysregulation in human diseases; (3) TFEB activators from natural products and their potential uses.

The dual-functional memantine nitrate MN-08 alleviates cerebral vasospasm and brain injury in experimental subarachnoid haemorrhage models.

BACKGROUND AND PURPOSE: Cerebral vasospasm and neuronal apoptosis after subarachnoid haemorrhage (SAH) is the major cause of morbidity and mortality in SAH patients. So far, single-target agents have not prevented its occurrence. Memantine, a non-competitive NMDA re3ceptor antagonist, is known to alleviate brain injury and vasospasm in experimental models of SAH. Impairment of NO availability also contributes to vasospasm. Recently, we designed and synthesized a memantine nitrate MN-08, which has potent dual functions: neuroprotection and vasodilation. Here, we have tested the therapeutic effects of MN-08 in animal models of SAH. EXPERIMENTAL APPROACH: Binding to NMDA receptors (expressed in HEK293 cells), NO release and vasodilator effects of MN-08 were assessed in vitro. Therapeutic effects of MN-08 were investigated in vivo, using rat and rabbit SAH models. KEY RESULTS: MN-08 bound to the NMDA receptor, slowly releasing NO in vitro and in vivo. Consequently, MN-08 relaxed the pre-contracted middle cerebral artery ex vivo and increased blood flow velocity in small vessels of the mouse cerebral cortex. It did not, however, lower systemic blood pressure. In an endovascular perforation rat model of SAH, MN-08 improved the neurological scores and ameliorated cerebral vasospasm. Moreover, MN-08 also alleviated cerebral vasospasm in a cisterna magna single-injection model in rabbits. MN-08 attenuated neural cell apoptosis in both rat and rabbit models of SAH. Importantly, the therapeutic benefit of MN-08 was greater than that of memantine. CONCLUSION AND IMPLICATIONS: MN-08 has neuroprotective potential and can ameliorate vasospasm in experimental SAH models.

Proteomic analysis reveals the potential neuroprotective effects of tetramethylpyrazine dimer in neuro2a/APPswe cells.

Alzheimer's disease (AD) is a common neurodegenerative disease characterized by pathological processes, including abnormal amyloid deposits and filament tangles, oxidative stress, neuroinflammation, and neurotrophic insufficiency, leading to chronic and prolonged neuronal loss and cognitive deficits. Tetramethylpyrazine (TMP) is one of the main active components of Ligusticum wallichii, a traditional Chinese medicine widely used for brain related disease. Here, we synthesized the TMP derivative tetramethylpyrazine dimer (DTMP), and evaluated the potential mechanisms underlying its potential neuroprotective effects using the murine neuron-like cells (N2a) transfected with the human "Swedish" mutant amyloid precursor protein (N2aAPP). ELISA results indicated that DTMP reduced the levels of Aß1-40 and Aß1-42 in N2aAPP. Then through proteomic analysis we identified a total of 208 differentially expressed proteins in N2aAPP cells compared to the wild-type N2a cells (N2aWT), including 144 increased and 64 decreased proteins. 449 differentially expressed proteins were revealed in N2aAPP cells on DTMP treatment with 69 increased and 380 decreased proteins. Bioinformatic analysis suggested that these proteins are enriched in mitochondrial function, the electronic transmission chain, ATP binding, oxidative phosphorylation, GTPase function, the transcriptional translation process, amino acid metabolism, nucleotide binding and others. Given the vital role of mitochondria in the pathogenesis of AD, we selected the electron transport chain pathway-related molecules to further validate these findings. Western-blot analysis demonstrated that DTMP significantly increased the levels of complex I (NDUAA), complex II (SDHB), complex III (UCRI), complex IV (COX5A) and complex V (ATP5A) in N2aAPP cells. The modulation of dysregulated proteins implicated in AD pathogenesis implies the pharmacological mechanisms of DTMP and its potential as a novel therapeutic choice in AD.

A Novel Tetramethylpyrazine Derivative Protects Against Glutamate-Induced Cytotoxicity Through PGC1α/Nrf2 and PI3K/Akt Signaling Pathways.

Glutamate-induced excitotoxicity is one of the main causes of neuronal cell death in stroke. Compound 22a has been previously reported as a promising neuroprotective compound derived from tetramethylpyrazine, which is a widely used active ingredient of traditional Chinese medicine Chuanxiong (Ligusticum wallichii Franchat). Compound 22a can protect neurons from oxidative stress-induced PC12 cell death and alleviates the infarct areas and brain edema in a rat permanent middle cerebral artery occlusion model. In the current work, we further investigated the neuroprotective effects and underlying mechanisms of compound 22a against glutamate-induced excitotoxicity in primary culture of rat cerebellar granule neurons (CGNs). We found that pretreatment with compound 22a prevented glutamate-induced neuronal damage by maintaining mitochondrial membrane potential and attenuating cellular apoptosis. Compound 22a could also enhance peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC1α) transcriptional activity and induce nuclear accumulation of Nrf2 in PC12 cells. Accordingly, pretreatment with compound 22a reversed the glutamate-induced down-regulation of expression of the proteins PGC1α, transcriptional factor NF-E2-related factor 2 (Nrf2), and hemooxygenase 1 (HO-1). In addition, compound 22a increased the phosphorylation of phosphoinositide 3-kinase (p-PI3K), phosphorylated protein kinase B (p-Akt), and glycogen synthase kinase 3ß (p-GSK3ß). Meanwhile, the small interfering RNA-mediated silencing of PGC1α expression and selective inhibitors targeting PI3K/Akt (LY294002 and Akt-iv) could significantly attenuate the neuroprotective effect of compound 22a. Taken together, compound 22a protected against glutamate-induced CGN injury possibly in part through regulation of PGC1α/Nrf2 and PI3K/Akt pathways.

Neuroprotective Effect and Mechanism of Action of Tetramethylpyrazine Nitrone for Ischemic Stroke Therapy.

Our previous studies demonstrated that the multifunctional agent TBN, a derivative of tetramethylpyrazine armed with a nitrone moiety, displayed high therapeutic efficacy in experimental ischemic stroke models. However, its molecular mechanisms of action underlying the neuroprotective effect need further exploration. In the present study, we found that TBN had significant activities scavenging free radicals such as ·OH, O 2·- and ONOO-, inhibiting Ca2+ overload, maintaining mitochondrial function and preventing neuronal damage in primary cortical cultures. Further, TBN was effective in reducing brain infarction and ameliorating impairment of behavioral functions in the permanent middle cerebral artery occlusion (p-MCAo) rat model. TBN down-regulated the expression of pro-apoptotic factors Bax, while up-regulated the expression of anti-apoptotic factor Bcl-2 and increased the expression of pro-survival factors including p-Akt and p-GSK3ß in the peri-infarct cortex of p-MCAo rats. In addition, LY-294002 (a PI3K inhibitor) and MK2206 (an Akt inhibitor) significantly blocked the protective effect of TBN against OGD-induced death of cortical neurons. Taken together, the multifunctional mechanisms including scavenging free radicals, blocking calcium overload, maintaining mitochondrial function and activating the PI3K/Akt/p-GSK3ß cell survival pathway were possibly involved in the neuroprotective effects of TBN, making it a promising clinical candidate for the treatment of ischemic stroke.

5-Hydroxycyclopenicillone, a New ß-Amyloid Fibrillization Inhibitor from a Sponge-Derived Fungus Trichoderma sp. HPQJ-34.

Abstract: A new cyclopentenone, 5-hydroxycyclopeni cillone (1), was isolated together with three known compounds, ar-turmerone (2), citreoisocoumarin (3), and 6-O-methyl-citreoisocoumarin (4), from a culture of the sponge-derived fungus Trichoderma sp. HPQJ-34. The structures of 1-4 were characterized using comprehensive spectroscopic analyses. The absolute configuration of 1 was determined by comparison of electronic circular dichroism (ECD) spectra with literature values used for the reported analogue, cyclopenicillone (5), which was not isolated in this research. Compound 1 was shown to scavenge 2,2-diphenyl-1-picrylhydrazyl free radicals, and decrease ß-amyloid (Aß) fibrillization in vitro. Moreover, 1 significantly reduced H2O2-induced neurotoxicity in SH-SY5Y cells. These findings suggested that compound 1, a newly discovered cyclopentenone, has moderate anti-oxidative, anti-Aß fibrillization properties and neuroprotective effects, and might be a good free radical scavenger.

A Novel Danshensu-Tetramethylpyrazine Conjugate DT-010 Provides Cardioprotection through the PGC-1α/Nrf2/HO-1 Pathway.

In this study, we investigated the cardioprotective mechanisms of action of DT-010, a novel danshensu-tetramethylpyrazine conjugate. DT-010 significantly preserved cell viability and suppressed cell apoptosis in H9c2 cells injured by tert-butylhydroperoxide (t-BHP), iodoacetic acid (IAA) and hypoxia-reoxygenation. In addition, DT-010 pre-treatment reduced the intracellular level of free radicals including superoxide anion (·O2-), hydroxyl radical (·OH) and peroxynitrite anion (ONOO-) after t-BHP exposure. Moreover, DT-010 up-regulated the protein expression of peroxisome proliferator-activated receptor gamma coactivator 1 alpha (PGC-1α) and nuclear factor-E2-related factor 2 (Nrf2) as well as mitochondrial transcription factor A (Tfam) and heme oxygenase-1 (HO-1) in H9c2 cells. DT-010 also triggered Nrf2 nuclear translocation. In a rat myocardial ischemia-reperfusion model, DT-010 significantly alleviated myocardial infarction. The results indicated that DT-010 may be a promising candidate for the treatment of cardiovascular diseases, particularly myocardial ischemia and reperfusion injury.

Discovery, Synthesis, and Functional Characterization of a Novel Neuroprotective Natural Product from the Fruit of Alpinia oxyphylla for use in Parkinson's Disease Through LC/MS-Based Multivariate Data Analysis-Guided Fractionation.

Herein we report the discovery of a novel lead compound, oxyphylla A [(R)-4-(2-hydroxy-5-methylphenyl)-5-methylhexanoic acid] (from the fruit of Alpinia oxyphylla), which functions as a neuroprotective agent against Parkinson's disease. To identify a shortlist of candidates from the extract of A. oxyphylla, we employed an integrated strategy combining liquid chromatography/mass spectrometry, bioactivity-guided fractionation, and chemometric analysis. The neuroprotective effects of the shortlisted candidates were validated prior to scaling up the finalized list of potential neuroprotective constituents for more detailed chemical and biological characterization. Oxyphylla A has promising neuroprotective effects: (i) it ameliorates in vitro chemical-induced primary neuronal cell damage and (ii) alleviates chemical-induced dopaminergic neuron loss and behavioral impairment in both zebrafish and mice in vivo. Quantitative proteomics analyses of oxyphylla A-treated primary cerebellar granule neurons that had been intoxicated with 1-methyl-4-phenylpyridinium revealed that oxyphylla A activates nuclear factor-erythroid 2-related factor 2 (NRF2)-a master redox switch-and triggers a cascade of antioxidative responses. These observations were verified independently through western blot analyses. Our integrated metabolomics, chemometrics, and pharmacological strategy led to the efficient discovery of novel bioactive ingredients from A. oxyphylla while avoiding the nontargeting, labor-intensive steps usually required for identification of bioactive compounds. Our successful development of a synthetic route toward oxyphylla A should lead to its availability on a large scale for further functional development and pathological studies.

Potent Protection Against MPP+-Induced Neurotoxicity via Activating Transcription Factor MEF2D by a Novel Derivative of Naturally Occurring Danshensu/Tetramethylpyrazine.

Danshensu (DSS) and tetramethylpyrazine (TMP) are active ingredients of Salvia miltiorrhiza Bge. and Ligusticum chuanxiong Hort that are widely used in oriental medicine. Structural combination of compounds with known biological activity may lead to the formation of a molecule with multiple properties or new function profile. In the current study, the neuroprotective effects of DT-010, a novel analogue in which TMP was coupled to DSS through an ester bond and two allyl groups at the carboxyl group, were evaluated in a cellular model of Parkinson's disease (PD). As evidenced by the increase in cell survival, as well as the decrease in the number of Hoechst-stained apoptotic nuclei and the level of intracellular accumulation of reactive oxygen species, DT-010 at 3-30 µM substantially protected against MPP+-induced neurotoxicity in both PC12 cells and primary cerebellar granule neurons, a protection that was more potent and efficacious than its parent molecules DSS and TMP. Very encouragingly, we found that DT-010, but not DSS or TMP, could enhance myocyte enhancer factor 2D (MEF2D) transcriptional activity using luciferase reporter gene assay. The neuroprotective effects of DT-010 could be blocked by pharmacologic inhibition of PI3K pathways with LY294002, or MEF2D pathway with short hairpin RNA-mediated knockdown of MEF2D. Furthermore, western blot analysis revealed that DT-010 potentiates Akt protein expression against MPP+ to down-regulate MEF2D inhibitor GSK3ß. Taken together, the results suggest that DT-010 prevents MPP+-induced neurotoxicity via enhancing MEF2D through the activation of PI3K/Akt/GSK3ß pathway. DT-010 may be a potential candidate for further preclinical study for preventing and treating PD.

Fully automated multidimensional reversed-phase liquid chromatography with tandem anion/cation exchange columns for simultaneous global endogenous tyrosine nitration detection, integral membrane protein characterization, and quantitative proteomics mapping in cerebral infarcts.

Protein tyrosine nitration (PTN) is a signature hallmark of radical-induced nitrative stress in a wide range of pathophysiological conditions, with naturally occurring abundances at substoichiometric levels. In this present study, a fully automated four-dimensional platform, consisting of high-/low-pH reversed-phase dimensions with two additional complementary, strong anion (SAX) and cation exchange (SCX), chromatographic separation stages inserted in tandem, was implemented for the simultaneous mapping of endogenous nitrated tyrosine-containing peptides within the global proteomic context of a Macaca fascicularis cerebral ischemic stroke model. This integrated RP-SA(C)X-RP platform was initially benchmarked through proteomic analyses of Saccharomyces cerevisiae, revealing extended proteome and protein coverage. A total of 27 144 unique peptides from 3684 nonredundant proteins [1% global false discovery rate (FDR)] were identified from M. fascicularis cerebral cortex tissue. The inclusion of the S(A/C)X columns contributed to the increased detection of acidic, hydrophilic, and hydrophobic peptide populations; these separation features enabled the concomitant identification of 127 endogenous nitrated peptides and 137 transmembrane domain-containing peptides corresponding to integral membrane proteins, without the need for specific targeted enrichment strategies. The enhanced diversity of the peptide inventory obtained from the RP-SA(C)X-RP platform also improved analytical confidence in isobaric tags for relative and absolute quantitation (iTRAQ)-based proteomic analyses.

Examining the neuroprotective effects of protocatechuic acid and chrysin on in vitro and in vivo models of Parkinson disease.

Polypharmacology-based strategies using drug combinations with different mechanisms of action are gaining increasing attention as a novel methodology to discover potentially innovative medicines for neurodegenerative disorders. We used this approach to examine the combined neuroprotective effects of two polyphenols, protocatechuic acid (PCA) and chrysin, identified from the fruits of Alpinia oxyphylla. Our results demonstrated synergistic neuroprotective effects, with chrysin enhancing the protective effects of PCA, resulting in greater cell viability and decreased lactate dehydrogenase release from 6-hydroxydopamine-treated PC12 cells. Their combination also significantly attenuated chemically induced dopaminergic neuron loss in both zebrafish and mice. We examined the molecular mechanisms underlying these collective cytoprotective effects through proteomic analysis of treated PC12 cells, resulting in the identification of 12 regulated proteins. Two were further characterized, leading to the determination that pretreatment with PCA and chrysin resulted in (i) increased nuclear factor-erythroid 2-related factor 2 protein expression and transcriptional activity; (ii) modulation of cellular redox status with the upregulated expression of hallmark antioxidant enzymes, including heme oxygenase-1, superoxide dismutase, and catalase; and (iii) decreased levels of malondialdehyde, a known lipid peroxidation product. Treatment with PCA and chrysin also inhibited activation of nuclear factor-κB and expression of inducible nitric oxide synthase. Our findings suggest that natural products, when used in combination, can be effective potential therapeutic agents for treating diseases such as Parkinson disease. A therapy involving both PCA and chrysin exhibits its enhanced neuroprotective effects through a combination of cellular mechanisms: antioxidant cytoprotection and anti-inflammation.

Andrographolide derivative AL-1 improves insulin resistance through down-regulation of NF-κB signalling pathway.

BACKGROUND AND PURPOSE: Andrographolide is the most active constituent of the medicinal plant Andrographis paniculata. Previously, we synthesized a novel andrographolide derivative AL-1, conjugating andrographolide with lipoic acid. Although the antioxidative and/or anti-inflammatory activity of AL-1 contributes to its cytoprotective effects, whether AL-1 can improve insulin resistance and the mechanisms responsible for its action have not been elucidated. EXPERIMENTAL APPROACH: We investigated the anti-hyperlipidaemic and anti-hyperglycaemic effects of AL-1 in a high-fat diet/streptozocin-induced animal diabetic model. In addition, we investigated the effect of AL-1 on the NF-κB signalling pathway in rat islet derived insulinoma cells (RIN-m cells) with a focus on the link between reactive oxygen species-associated inflammation and insulin resistance. KEY RESULTS: AL-1, at doses of 40 and 80 mg · kg(-1), had a significant hypoglycaemic effect; it significantly reduced the level of cholesterol and increased HDL. AL-1 also reduced the homeostasis model assessment of insulin resistance and enhanced insulin sensitivity. In addition, AL-1 improved the morphology of pancreatic islets and their function. Furthermore, AL-1 suppressed high glucose-induced phosphorylation of p65 and IκBα in RIN-m cells. CONCLUSION AND IMPLICATIONS: AL-1 has a hypoglycaemic effect and improves insulin resistance in type 2 diabetic rats. It protected islet from high glucose-induced oxidative damage by down-regulating the NF-κB signalling pathway. Further investigations of AL-1 as a promising new agent for treatment and/or prevention of diabetes are warranted.

Therapeutic effects of multifunctional tetramethylpyrazine nitrone on models of Parkinson's disease in vitro and in vivo.

Parkinson's disease (PD) is the second most common neurodegenerative disease. Although the etiology of PD is not completely understood, it is well-documented that oxidative stress and Ca(2+)-mediated cellular damage play important roles in the progression of PD. 2-[[(1,1-Dimethylethyl)oxidoimino]-methyl]-3,5,6-trimethylpyrazine (TBN), a novel nitrone derivative of tetramethylpyrazine, has shown significant therapeutic effects in stroke models due to its multiple functions, including calcium overload blockade and free radical-scavenging. In this study, we investigated the neuroprotective and neurorescue effects of TBN on various in vitro and in vivo models of PD and explored its possible mechanisms of action. The results show that TBN exerted significant neuroprotection on 1-methyl-4-phenylpyridinium (MPP(+))-induced damage in SH-SY5Y cells and primary dopaminergic neurons, as well as on 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced dopaminergic neuron loss in zebrafish (TBN and MPTP were added simultaneously into the fish embryo medium and the treatment period was 48 h). In the MPTP-induced mouse and 6-hydroxydopamine (6-OHDA)-induced rat PD models, TBN administrated orally twice daily for 14 d (3 d post-MPTP lesion in mice and 7 d post-6-OHDA lesion in rats) exhibited remarkable neurorescue effects to increase the number of dopaminergic neurons. In addition, TBN improved apomorphine-induced rotational behavior in the 6-OHDA-lesioned PD rats. TBN suppressed the MPP(+)-induced intracellular reactive oxygen species (ROS) in SH-SY5Y cells, increased the superoxide dismutase (SOD) activity and glutathione (GSH) concentration in the substantial nigra of MPTP-treated mice. These data indicate that TBN protects and rescues dopaminergic neurons from MPP(+) and MPTP/6-OHDA-induced damage by reducing ROS and increasing cellular antioxidative defense capability.

Anti-Lung-Cancer Activity and Liposome-Based Delivery Systems of ß-Elemene.

In the past decade, ß-elemene played an important role in enhancing the effects of many anticancer drugs and was widely used in the treatment of different kinds of malignancies and in reducing the side effects of chemotherapy. Further study showed that it is also a promising anti-lung cancer drug. However, the clinical application of ß-elemene was limited by its hydrophobic property, poor stability, and low bioavailability. With the development of new excipients and novel technologies, plenty of novel formulations of ß-elemene have improved dramatically, which provide a positive perspective in terms of clinical application for ß-elemene. Liposome as a drug delivery system shows great advantages over traditional formulations for ß-elemene. In this paper, we summarize the advanced progress being made in anti-lung cancer activity and the new liposomes delivery systems of ß-elemene. This advancement is expected to improve the level of pharmacy research and provide a stronger scientific foundation for further study on ß-elemene.

Synthesis and preliminary anticancer evaluation of 10-hydroxycamptothecin analogs.

We have synthesized new 10-hydroxycamptothecin (HCPT) analogs and evaluated their anticancer activity in cell culture and in experimental animal tumor model. Although the new analogs were less potent against L1210 leukemia cells in vitro, some of them were more efficacious against L1210 leukemia in vivo compared to the parent HCPT.

Ethanolic extract of fructus Alpinia oxyphylla protects against 6-hydroxydopamine-induced damage of PC12 cells in vitro and dopaminergic neurons in zebrafish.

In an attempt to understand the neuroprotective effect of Fructus Alpinia oxyphylla (AOE) and to elucidate its underlying mechanism of action, the ethanolic extract of AOE was investigated using zebrafish and PC12 cell models. AOE prevented and restored 6-hydroxydopamine (6-OHDA)-induced dopaminergic (DA) neuron degeneration and attenuated a deficit of locomotor activity in a zebrafish (Danio rerio) model of Parkinson's disease (PD). Treatment with AOE increased the viability of 6-OHDA-treated PC12 cells in vitro in a dose-dependent manner by attenuating cellular apoptosis. However, protocatechuic acid (PCA) and chrysin, two known polyphenol components of AOE, could not reproduce the neuroprotective activity of AOE in the PD zebrafish or PC12 cell models. A mechanistic study found that the protective effect of AOE against 6-OHDA-induced neuronal injury involved anti-inflammatory action (down-regulation of gene expression of IL-1ß and TNF-α) and anti-oxidative action (inhibition of NO production and iNOS expression in PC12 cells). Moreover, the PI3K-AKT pathway might be part of the mechanism of neuroprotection of AOE. The results of this research are expected to provide a scientific rationale for the use of AOE in the treatment of PD. However, it is important that the active components that contribute to the neuroprotective action of AOE are identified and characterized.