Preparation, In Vitro and In Vivo Evaluation of Nanoemulsion In Situ Gel for Transnasal Delivery of Traditional Chinese Medicine Volatile Oil from Ligusticum sinense Oliv.cv. Chaxiong.

Ischemic stroke is a difficult-to-treat brain disease that may be attributed to a limited therapeutic time window and lack of effective clinical drugs. Nasal-brain administration is characterized by low systemic toxicity and is a direct and non-invasive brain targeting route. Preliminary studies have shown that the volatile oil of Chaxiong (VOC) has an obvious anti-ischemic stroke effect. In this work, we designed a nanoemulsion thermosensitive in situ gel (VOC-NE-ISG) loaded with volatile oil of Chaxiong for ischemia via intranasal delivery to rat brain treatment of cerebral ischemic stroke. The developed VOC-NE-ISG formulation has a suitable particle size of 21.02 ± 0.25 nm and a zeta potential of -20.4 ± 1.47 mV, with good gelling ability and prolonged release of the five components of VOC. The results of in vivo pharmacokinetic studies and brain targeting studies showed that intranasal administration of VOC-NE-ISG could significantly improve the bioavailability and had excellent brain-targeting efficacy of nasal-to-brain delivery. In addition, the results of pharmacodynamics experiments showed that both VOC-NE and VOC-NE-ISG could reduce the neurological deficit score of model rats, reducing the size of cerebral infarction, with a significant effect on improving ischemic stroke. Overall, VOC-NE-ISG may be a promising intranasal nanomedicine for the effective treatment of ischemic stroke.

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.

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.

Curcumin attenuates surgery-induced cognitive dysfunction in aged mice.

Post-operative cognitive dysfunction (POCD) is associated with elderly patients undergoing surgery. However, pharmacological treatments for POCD are limited. In this study, we found that curcumin, an active compound derived from Curcuma longa, ameliorated the cognitive dysfunction following abdominal surgery in aged mice. Further, curcumin prevented surgery-induced anti-oxidant enzyme activity. Curcumin also increased brain-derived neurotrophic factor (BDNF)-positive area and expression of pAkt in the brain, suggesting that curcumin activated BDNF signaling in aged mice. Furthermore, curcumin neutralized cholinergic dysfunction involving choline acetyltransferase expression induced by surgery. These results strongly suggested that curcumin prevented cognitive impairments via multiple targets, possibly by increasing the activity of anti-oxidant enzymes, activation of BDNF signaling, and neutralization of cholinergic dysfunction, concurrently. Based on these novel findings, curcumin might be a potential agent in POCD prophylaxis and treatment.

The Pyridyldiisopropylsilyl Group: A Masked Functionality and Directing Group for Monoselective ortho-Acyloxylation and ortho-Halogenation Reactions of Arenes.

A novel, easily removable and modifiable silicon-tethered pyridyldiisopropylsilyl directing group for C-H functionalizations of arenes has been developed. The installation of the pyridyldiisopropylsilyl group can efficiently be achieved via two complementary routes using easily available 2-(diisopropylsilyl)pyridine (5). The first strategy features a nucleophilic hydride substitution at the silicon atom in 5 with aryllithium reagents generated in situ from the corresponding aryl bromides or iodides. The second milder route exploits a highly efficient room-temperature rhodium(I)-catalyzed cross-coupling reaction between 5 and aryl iodides. The latter approach can be applied to the preparation of a wide range of pyridyldiisopropylsilyl-substituted arenes possessing a variety of functional groups, including those incompatible with organometallic reagents. The pyridyldiisopropylsilyl directing group allows for a highly efficient, regioselective palladium(II)-catalyzed mono-ortho-acyloxylation and ortho-halogenation of various aromatic compounds. Most impor-tantly, the silicon-tethered directing group in both acyloxylated and halogenated products can easily be removed or efficiently converted into an array of other valuable functionalities. These transformations include protio-, deuterio-, halo-, boro-, and alkynyldesilylations, as well as a conversion of the directing group into the hydroxy functionality. In addition, the construction of aryl-aryl bonds via the Hiyama-Denmark cross-coupling reaction is feasible for the acetoxylated products. Moreover, the ortho-halogenated pyridyldiisopropylsilylarenes, bearing both nucleophilic pyridyldiisopropylsilyl and electrophilic aryl halide moieties, represent synthetically attractive 1,2-ambiphiles. A unique reactivity of these ambiphiles has been demonstrated in efficient syntheses of arylenediyne and benzosilole derivatives, as well as in a facile generation of benzyne. In addition, preliminary mechanistic studies of the acyloxylation and halogenation reactions have been performed. A trinuclear palladacycle intermediate has been isolated from a stoichiometric reaction between diisopropyl-(phenyl)pyrid-2-ylsilane (3a) and palladium acetate. Furthermore, both C-H functionalization reactions exhibited equally high values of the intramolecular primary kinetic isotope effect (kH/kD = 6.7). Based on these observations, a general mechanism involving the formation of a palladacycle via a C-H activation process as the rate-determining step has been proposed.

Synthesis, characterization, and in vivo targeted imaging of amine-functionalized rare-earth up-converting nanophosphors.

Rare-earth up-converting nanophosphors (UCNPs) have great potential to become a new generation of biological luminescent labels, but their use has been limited by difficulties in obtaining water-soluble UCNPs bearing appropriate functional groups. To address this problem, we report herein a simple and efficient procedure for the preparation of amine-functionalized UCNPs by a modified hydrothermal microemulsion route assisted with 6-aminohexanoic acid. The amine content of the resultant UCNPs has been determined to be (9.5+/-0.8) x 10(-5) mol/g, which not only confers excellent dispersibility in aqueous solution, but also allows further conjugation with targeted molecules such as folic acid (FA) as a ligand. By means of the laser scanning up-conversion luminescence microscopy (LSUCLM) and the in vivo up-conversion luminescence (UCL) imaging under excitation at the CW infrared laser at 980 nm, FA-coupled UCNPs have been demonstrated to be effective in targeting folate-receptor overexpressing HeLa cells in vitro and HeLa tumor in vivo and ex vivo. These results indicated that our UCNPs could be used as whole-body targeted UCL imaging agents.

Highly sensitive and fast responsive fluorescence turn-on chemodosimeter for Cu2+ and its application in live cell imaging.

A rhodamine B derivative 4 containing a highly electron-rich S atom has been synthesized as a fluorescence turn-on chemodosimeter for Cu(2+). Following Cu(2+)-promoted ring-opening, redox and hydrolysis reactions, comparable amplifications of absorption and fluorescence signals were observed upon addition of Cu(2+); this suggests that chemodosimeter 4 effectively avoided the fluorescence quenching caused by the paramagnetic nature of Cu(2+). Importantly, 4 can selectively recognize Cu(2+) in aqueous media in the presence of other trace metal ions in organisms (such as Fe(3+), Fe(2+), Cu(+), Zn(2+), Cr(3+), Mn(2+), Co(2+), and Ni(2+)), abundant cellular cations (such as Na(+), K(+), Mg(2+), and Ca(2+)), and the prevalent toxic metal ions in the environment (such as Pb(2+) and Cd(2+)) with high sensitivity (detection limit < or =10 ppb) and a rapid response time (< or =1 min). Moreover, by virtue of the chemodosimeter as fluorescent probe for Cu(2+), confocal and two-photon microscopy experiments revealed a significant increase of intracellular Cu(2+) concentration and the subcellular distribution of Cu(2+), which was internalized into the living HeLa cells upon incubation in growth medium supplemented with 50 muM CuCl(2) for 20 h.