Divanillyl sulfone suppresses NLRP3 inflammasome activation via inducing mitophagy to ameliorate chronic neuropathic pain in mice.

BACKGROUND: Chronic neuropathic pain is a frequent sequel to peripheral nerve injury and maladaptive nervous system function. Divanillyl sulfone (DS), a novel structural derivative of 4,4'-dihydroxydibenzyl sulfoxide from a traditional Chinese medicine Gastrodia elata with anti-nociceptive effects, significantly alleviated neuropathic pain following intrathecal injection. Here, we aimed to investigate the underlying mechanisms of DS against neuropathic pain. METHODS: A chronic constrictive injury (CCI) mouse model of neuropathic pain induced by sciatic nerve ligation was performed to evaluate the effect of DS by measuring the limb withdrawal using Von Frey filament test. Immunofluorescence staining was used to assess the cell localizations and expressions of Iba-1, ASC, NLRP3, and ROS, the formation of autolysosome. The levels of NLRP3-related proteins (caspase-1, NLRP3, and IL-1ß), mitophagy-related proteins (LC3, Beclin-1, and p62), and apoptosis-related proteins (Bcl-XL and Bax) were detected by Western blotting. The apoptosis of BV-2 cell and caspase activity were evaluated by flow cytometry. RESULTS: DS significantly alleviated the neuropathic pain by increasing the mechanical withdrawal threshold and inhibiting the activation of NLRP3 in CCI-induced model mice. Our findings indicated that DS promoted the mitophagy by increasing the LC3II and Beclin 1 and decreasing the levels of p62 protein in BV-2 cell. This is accompanied by the inhibition of NLRP3 activation, which was shown as inhibited the expression of NLRP3 in lysates as well as the secretion of mature caspase-1 p10 and IL-1ß p17 in supernatants in cultured BV-2 microglia. In addition, DS could promote mitophagy-induced improvement of dysfunctional mitochondria by clearing intracellular ROS and restoring mitochondrial membrane potential. CONCLUSION: Together, our findings demonstrated that DS ameliorate chronic neuropathic pain in mice by suppressing NLRP3 inflammasome activation induced by mitophagy in microglia. DS may be a promising therapeutic agent for chronic neuropathic pain.

Minor triterpenes from an aqueous extract of the hook-bearing stem of Uncaria rhynchophylla.

Six new triterpenes, uncarinic acids KP (1-6), along with 24 known analogues, were isolated as minor constituents of an aqueous decoction of the hook-bearing stems of Uncaria rhynchophylla (Gou-teng). By comprehensive spectroscopic data analysis, their structures were elucidated as derivatives of olean-12-en-28-oic acid and urs-12-en-28-oic acid with different oxidized forms at C-3, C-6, and/or C-23, respectively. Cell-based preliminary bioassay showed that the (E)-/(Z)-coumaroyloxy and (E)-/(Z)-feruloyloxy units at C-27 of olean-12-en-28-oic acid and urs-12-en-28-oic acid played roles in their bioactivities.[Formula: see text].

Design, synthesis, and biological evaluation of novel iso-flavones derivatives as H3R antagonists.

Histamine H3 receptor (H3R), a kind of G-protein coupled receptor (GPCR), is expressed mainly in the central nervous system (CNS) and plays a vital role in homoeostatic control. This study describes the design and synthesis of a series of novel H3R antagonists based on the iso-flavone scaffold. The results of the bioactivity evaluation show that four compounds (1c, 2c, 2h, and 2o) possess significant H3R inhibitory activities. Molecular docking indicates that a salt bridge, π-π T-shape interactions, and hydrophobic interaction all contribute to the interaction between compound 2h and H3R.

Total flavonoid extract from Dracoephalum moldavica L. attenuates ß-amyloid-induced toxicity through anti-amyloidogenesic and neurotrophic pathways.

AIMS: Alzheimer's disease (AD) is an incurable neurodegenerative disorder characterized by global cognitive impairment that involves accumulation of amyloid-beta peptides (Aß) in the brain. Herbal approaches can be used as alternative medicines to slow the progression of AD. This study aimed to determine the beneficial effects and potential underlying mechanisms of total flavonoid extract from Dracoephalum moldavica L. (TFDM) for attenuating Alzheimer-related deficits induced by Aß. MAIN METHODS: We used amyloid precursor protein (APP) and presenilin 1 (PS1) double transgenic mice and copper-injured APP Swedish mutation overexpressing SH-SY5Y cells to evaluate the beneficial effects of TFDM. Further, identifying the mechanisms of action was conducted on anti-amyloidogenic and neurotrophic transductions. KEY FINDINGS: Our results indicated that TFDM treatment ameliorated cognitive impairments and neurodegeneration and improved the antioxidant defense system in APP/PS1 mice. TFDM also reduced Aß burden by relieving Aß deposition, decreasing insoluble Aß levels, and inhibiting ß-amyloidogenic processing pathway involving downregulation of ß-secretase and ß-C-terminal fragment in the brain. In the in vitro model of AD, TFDM treatment protected injured cells, and combined with the beneficial effects of decreasing APP levels, lowered Aß1-42 and regulated the redox imbalance. Moreover, TFDM preserved the extracellular signal-regulated kinase/cAMP response element-binding protein/brain-derived neurotrophic factor pathway both in vitro and in vivo. SIGNIFICANCE: In conclusion, TFDM clearly demonstrated neuroprotective effects by restoring the anti-amyloidogenic and neurotrophic transductions in the context of AD-associated deficits. These findings indicate the potential use of herb-based substances as supplements or potential alternative supplements for attenuating the progression of AD.

Rhodoterpenoids A‒C, Three New Rearranged Triterpenoids from Rhododendron latoucheae by HPLC‒MS‒SPE‒NMR.

Rhodoterpenoids A‒C (1‒3), three new rearranged triterpenoids, together with one new biogenetically related compound, rhodoterpenoid D (4), were isolated and efficiently elucidated from Rhododendron latoucheae by high-performance liquid chromatography-mass spectrometry-solid-phase extraction-nuclear magnetic resonance (HPLC‒MS‒SPE‒NMR). Compounds 1 and 2 possess an unprecedented skeleton with a 5/7/6/6/6-fused pentacyclic ring system, while compound 3 contains a unique 6/7/6/6/6-fused pentacyclic carbon backbone. Their structures were determined by extensive spectroscopic methods and electronic circular dichroism (ECD) analyses. Plausible biogenetic pathways for 1‒4 were proposed. Compounds 1 and 4 showed potential activity against herpes simplex virus 1 (HSV-1) with IC50 values of 8.62 and 6.87 µM, respectively.

The Anti-Allergic Rhinitis Effect of Traditional Chinese Medicine of Shenqi by Regulating Mast Cell Degranulation and Th1/Th2 Cytokine Balance.

Shenqi is a traditional Chinese polyherbal medicine has been widely used for the treatment of allergic rhinitis (AR). The aim of this study was to investigate the anti-allergic rhinitis activity of Shenqi and explore its underlying molecular mechanism. Ovalbumin (OVA)-induced allergic rhinitis rat model was used to evaluate the anti-allergic rhinitis effect of Shenqi. The effect of Shenqi on IgE-mediated degranulation was measured using rat basophilic leukemia (RBL-2H3) cells. Primary spleen lymphocytes were isolated to investigate the anti-allergic mechanism of Shenqi by detecting the expression of transcription factors via Western blot and the level of cytokines (IL-4 and IFN-γ) via ELISA. In OVA-induced AR rat models, Shenqi relieved the allergic rhinitis symptoms, inhibited the histopathological changes of nasal mucosa, and reduced the levels of IL-4 and IgE. The results from the in vitro study certified that Shenqi inhibited mast cell degranulation. Furthermore, the results of GATA3, T-bet, p-STAT6, and SOCS1 expression and production of IFN-γ and IL-4 demonstrated that Shenqi balanced the ratio of Th1/Th2 (IFN-γ/IL-4) in OVA-stimulated spleen lymphocytes. In conclusion, these results suggest that Shenqi exhibits an obvious anti-allergic effect by suppressing the mast cell-mediated allergic response and by improving the imbalance of Th1/Th2 ratio in allergic rhinitis.

Wilfordonols A-D: four new norsesquiterpenes from the leaves of Tripterygium wilfordii.

Four new norsesquiterpenes wilfordonols A-D (1-4), along with three known compounds, sarmentol B (5), boscialin (6), and (+)-loliolide (7), were isolated from the leaves of Tripterygium wilfordii Hook.f.. The structures of the new compounds were elucidated on the basis of their spectroscopic analysis, and the absolute configuration of the compounds was confirmed by CD and modified Mosher's method. At a concentration of 10 µM, compounds 4, 6, and 7 inhibited signal transducer and activator of transcription 1 translocation by 34.27 ± 1.02%, 48.93 ± 1.76%, and 70.31 ± 2.20%, respectively.

Megastigmane Glycosides from the Leaves of Tripterygium wilfordii.

Two new megastigmane glycosides, named wilfordonisides A and B (1 and 2), and four known compounds (3-6) were isolated from the leaves of Tripterygium wilfordii, and one new aglycon, named wilfordoninol A (2a), was acquired by enzymatic hydrolysis of 2. The absolute stereostructures of the compounds were determined by Mosher's method and by CD. At a concentration of 10 µM, compounds 1, 3, and 5 inhibited STAT1 translocation by 38.1 ± 0.9%, 55.8 ± 0.8%, and 53.9 ± 1.0%, respectively.

Quercetin protects against the Aß(25-35)-induced amnesic injury: involvement of inactivation of rage-mediated pathway and conservation of the NVU.

Quercetin has demonstrated protective effects against Aß-induced toxicity on both neurons and endothelial cells. However, whether or not quercetin has an effect on the neurovascular coupling is unclear. In the present study, we aim to investigate the anti-amnesic effects of quercetin and to explore the underlying mechanisms. Aß(25-35) (10 nmol) was administrated to mice i.c.v. Quercetin was administrated orally for 8 days after injection. Learning and memory behaviors were evaluated by measuring spontaneous alternation in Morris Water Maze test and the step-through positive avoidance test. The regional cerebral blood flow was monitored before the Aß(25-35) injection and on seven consecutive days after injection. Mice were sacrificed and cerebral cortices were isolated on the last day. The effects of quercetin on the neurovascular unit (NVU) integrity, microvascular function and cholinergic neuronal changes, and the modification of signaling pathways were tested. Our results demonstrate that quercetin treatment for Aß(25-35)-induced amnesic mice improved the learning and memory capabilities and conferred robust neurovascular coupling protection, involving maintenance of the NVU integrity, reduction of neurovascular oxidation, modulation of microvascular function, improvement of cholinergic system, and regulation of neurovascular RAGE signaling pathway and ERK/CREB/BDNF pathway. In conclusion, in Aß(25-35)-induced amnesic mice, optimal doses of quercetin administration were beneficial. Quercetin protected the NVU likely through reduction of oxidative damage, inactivation of RAGE-mediated pathway and preservation of cholinergic neurons, offering an alternative medication for Alzheimer's disease.

Synthesis and anti-nociceptive and anti-inflammatory effects of gaultherin and its analogs.

The synthesis of gaultherin (1) and its analogs was carried out to provide 11 glycosides under phase-transfer catalytic conditions. The activities of all synthesized compounds were evaluated by nitric oxide production inhibitory assay in vitro. Methyl 2-O-(4-O-ß-d-galactopyranosyl)-ß-d-glucopyranosylbenzoate (5f) showed significantly anti-nociceptive and anti-inflammatory effects by the evaluation in vivo. Structure-activity relationships within these compounds were discussed.

Anti-inflammatory activity of methyl salicylate glycosides isolated from Gaultheria yunnanensis (Franch.) Rehder.

Gaultheria yunnanensis (Franch.) Rehder is a kind of traditional Chinese herbal medicine used for the treatments of rheumatoid arthritis, swelling and pain. Two methyl salicylate glycosides, namely methyl benzoate-2-O-ß-D-xylopyranosyl(1-6)-O-ß-D-gluco-pyranoside (J12122) and methyl benzoate-2-O-ß-D-xylopyranosyl(1-2)[O-ß-D-xylopyranosyl(1-6)]-O-ß-D-glucopyranoside (J12123), are natural salicylic derivatives isolated from Gaultheria yunnanensis. In this study, we investigated the anti-inflammatory activity of J12122 and J12123 on LPS-induced RAW264.7 macrophage cells by measuring the production of pro-inflammatory cytokines, accumulation of nitric oxide (NO), and level of reactive oxygen species (ROS). The results showed that both methyl salicylate glycosides dose-dependently inhibited the production of tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß), and IL-6, respectively. Consistent with these observations, J12122 and J12123 significantly suppressed the accumulation of NO, with an inhibitory rate of 56.20% and 51.72% at 3.0 µg/mL concentration, respectively. Furthermore, the two methyl salicylate glycosides reduced the level of ROS induced by LPS. These results showed that the isolated compounds possess anti-inflammatory properties through inhibition the production pro-inflammatory cytokines, NO, and ROS.

CPU0213, a non-selective ETA/ETB receptor antagonist, improves pulmonary arteriolar remodeling of monocrotaline-induced pulmonary hypertension in rats.

1. The aim of the present study was to explore the effects of CPU0213, a dual endothelin ET(A)/ET(B) receptor antagonist, and nifedipine, a calcium antagonist, in relieving pulmonary hypertension (PH). Both endothelin receptor and calcium antagonists have been reported to be effective in alleviating the remodelling of pulmonary arteries induced by monocrotaline (MCT) in rats. 2. After an initial single dose of 60 mg/kg, s.c., MCT, CPU0213 was administered to rats at doses of 25, 50 or 100 mg/kg, p.o., for 28 days. In addition, nifedipine was administered to another group of rats at a dose of 10 mg/kg, p.o., for 28 days. The haemodynamics of the right ventricle, pulmonary vascular activity, remodelling of the pulmonary arterioles (< 150 microm) and biochemical changes were evaluated. 3. Right ventricular systolic pressure (RVSP), central venous pressure (CVP), the maximum rate of uprising pressure (dP/dT(max)) and the weight index of the right ventricle were significantly elevated in MCT-treated rats. In addition, increases in pulmonary endothelin-1, malonyldialdehyde (MDA) and hydroxyproline content and a reduction in superoxide dismutase activity was found after MCT treatment. The thickness and area of the pulmonary arterial wall were significantly increased in MCT-treated rats compared with control rats. At all three doses tested, CPU0213 ameliorated these changes in a dose-dependent manner and the effects were associated with a greater reduction in the remodelling of pulmonary arterioles. However, nifedipine was only partially effective in amelerioating biochemical and haemodynamic changes induced by MCT, significantly reducing RVSP, CVP, +dp/dt(max), tissue MDA, inducible nitric oxide synthase and hydroxyproline content, increasing -dp/dt(min) and having no effect on the other parameters investigated. In addition, nifedipine had no effect on remodelling of the arterial wall. 4. In conclusion, CPU0213 is more effective than nifedipine in suppressing the remodelling of pulmonary arterioles in PH induced by MCT treatment of rats. Furthermore, CPU0213 may have promise in treating PH secondary to connective tissue disease.

[High throughput screening for glutathione S-transferase inhibitors].

To identify the inhibitor of glutathione S-transferase (GST), a high-throughput screening method was established in a 384-well microplate with total 35 microL volume, and the absorbance at 340 nm is detected. The concentrations of substrates, CDNB and GST were determined by chromatometry. The optimal enzyme kinetics reaction time and temperature are 2 h and 30 degrees C , respectively. The established model was evaluated by NaOCl, a known GST inhibitor, and the parameter Z' was 0.77, which showed a high feasibility and stability of the assay. A total of 31,098 compounds were screened, of which 4 compounds were shown to inhibit GST activity, high inhibiting activity for their IC50 of GST inhibition was 3.94, 4.05, 74.85, and 77.41 mg x L(-1), separately. The results indicated that the colorimetric method by using CDNB and GSH as substrate is stable, sensitive, reproducible and also suitable for high throughput screening.

[Identification of ligands for human LOX-1 through fluorescence polarization-based high throughput screening].

AIM: To develop a fluorescence polarization-based high throughput screening and identify ligands for human Lectin-like oxidized low-density lipoprotein receptor-1 (hLOX-1). METHODS: Sequential ultracentrifugation at 4 degrees C from normolipidemic fasting volunteers to obtain low density lipoprotein (LDL), which was modified by CuSO4 (5 micromol x L(-1)) at 37 degrees C for 24 h. The assay was based on the interaction between receptor and ligand, and hLOX-1 was labeled by FITC and bound to its specific ligand, oxLDL. Different reaction time and DMSO concentration were optimized to determine the stability and tolerance of fluorescence polarization (FP) assay. 3 200 compounds were screened in black 384-well microplate by FP-based competitive displacement assay, at excitation filter of 485 nm and emission filter of 530 nm. Z' was used to assess the assay quality. RESULTS: The FP-based HTS was formatted in a 384-well microplate with a Z' factor of 0. 75, and three active compounds for hLOX-1 were identified with IC50 below 40 micromol x L(-1) from total 3 200 compounds. CONCLUSION: The results indicated that the fluorescence polarization assay is stable, sensitive, reproducible and well suited for high throughput screening efforts.

Pharmacological efficacy of CPU 86017 on hypoxic pulmonary hypertension in rats: mediated by direct inhibition of calcium channels and antioxidant action, but indirect effects on the ET-1 pathway.

Endothelin-1 (ET-1) plays a key role in the pathogenesis of pulmonary hypertension. The present study was conducted to examine the effects of a novel compound p-chlorobenzyltetrahydroberberine (CPU 86017) on endothelin-1 system of hypoxia-induced pulmonary hypertension in rats. SD male rats were divided into control, untreated pulmonary hypertension, nifedipine (10 mg/kg p.o.), and CPU 86017 (80, 40, and 20 mg/kg p.o.) groups. The pulmonary hypertension was established by housing the rats in a hypoxic (10 +/- 0.5% oxygen) chamber 8 hours per day for 4 weeks. Hemodynamic and morphologic assessment exhibited a significant increase in the central vein pressure (CVP), right ventricular systolic pressure (RVSP), and pulmonary arteriole remodeling in the pulmonary hypertensive rats, which were improved by CPU 86017 80 and 40 mg/kg administration (P < 0.01). The elevated pulmonary endothelin-1 level and the over-active preproET-1 and iNOS mRNA expression were also decreased significantly (P < 0.01) in CPU 86017 groups. The maladjustment of redox enzyme system in pulmonary hypertension rats was corrected after treatment. We concluded that CPU 86017 improves pulmonary hypertension mainly to suppress the endothelin-1 pathway at the upstream and downstream via calcium antagonism and antioxidative action, then, resulting in a relief in pathogenesis of the disease.