Self-Assembled Nanoparticles from Xie-Bai-San Decoction: Isolation, Characterization and Enhancing Oral Bioavailability.

Background: Natural nanoparticles have been found to exist in traditional Chinese medicine (TCM) decoctions. However, whether natural nanoparticles can influence the oral bioavailability of active compounds has not been elucidated. Using Xie-Bai-San decoction (XBSD) as an example, the purpose of this study was to isolate, characterize and elucidate the mechanism of the nanoparticles (N-XBSD) in XBSD, and further to explore whether the bioavailability of the main active compounds could be enhanced by N-XBSD. Methods: N-XBSD were isolated from XBSD, and investigated its characterization and study of its formation mechanism, and evaluation of its ability to enhance bioavailability of active compounds. Results: The N-XBSD was successfully isolated with the average particle size of 104.53 nm, PDI of 0.27 and zeta potential of -5.14 mV. Meanwhile, all the eight active compounds were most presented in N-XBSD. Kukoamine B could self-assemble with mulberroside A or liquiritin to form nanoparticles, respectively. And the FT-IR and HRMS results indicated the possible binding of the ammonium group of kukoamine B with the phenolic hydroxyl group of mulberroside A or liquiritin, respectively. The established UPLC-MS/MS method was accurate and reliable and met the quantitative requirements. The pharmacokinetic behaviors of the N-XBSD and decoction were similar in rats. Most notably, compared to that of free drugs, the Cmax, AUC0-∞, AUC0-t, T1/2 and MRT0-∞ values of index compounds were the higher in N-XBSD, with a slower plasma clearance rate in rats. Conclusion: The major active compounds of XBSD were mainly distributed in N-XBSD, and N-XBSD was formed through self-assembly among active compounds. N-XBSD could obviously promote the bioavailability of active compounds, indicating natural nanoparticles of decoctions play an important role in therapeutic effects.

Unlocking the anticancer activity of gambogic acid: a shift towards ferroptosis via a GSH/Trx dual antioxidant system.

Nuclear factor erythroid 2-related factor 2 (Nrf2) plays a crucial role in ferroptosis by regulating the cellular antioxidant response and maintaining redox balance. However, compounds that induce ferroptosis through dual antioxidant pathways based on Nrf2 have not been fully explored. In our study, we investigated the impact of Gambogic acid (GA) on MCF-7 cells and HepG2 cells in vitro. The cytotoxicity, colony formation assay and cell cycle assay demonstrated potent tumor-killing ability of GA, while its effect was rescued by ferroptosis inhibitors. Furthermore, RNA sequencing revealed the enrichment of ferroptosis pathway mediated by GA. In terms of ferroptosis indicators detection, evidences for GA were provided including reactive oxygen species (ROS) accumulation, alteration in mitochondrial membrane potential (MMP), disappearance of mitochondrial cristae, lipid peroxidation induction, malondialdehyde (MDA) accumulation promotion, iron ion accumulation as well as glutathione (GSH)/thioredoxin (Trx) depletion. Notably, Ferrostatin-1 (Fer-1) and Liproxstatin-1 (Lip-1) successfully rescued GA-induced MDA accumulation. In terms of mechanism, Nrf2 was found to play a pivotal role in GA-induced ferroptosis by inducing protein alterations through the iron metabolism pathway and GSH/Trx dual antioxidant pathway. Furthermore, GA exerted good antitumor activity in vivo through GSH/Trx dual antioxidant pathway, and Fer-1 significantly attenuated its efficacy. In conclusion, our findings first provided new evidence for GA as an inducer of ferroptosis, and Nrf2-mediated GSH/Trx dual antioxidant system played an important role in GA-induced ferroptosis.

CD44-Targeted Photoactivatable Polymeric Nanosystem with On-Demand Drug Release as a "Photoactivatable Bomb" for Combined Photodynamic Therapy-Chemotherapy of Cancer.

Nowadays, the combined use of chemotherapy and photodynamic therapy (PDT) remains the most popular strategy for cancer treatment with high theraprutic efficacy. However, targeted therapy with the on-demand release of drugs is what most clinical treatments lack, leading to heavy side effects. Herein, a new CD44-targeted and red-light-activatable nanosystem, Ru-HA@DOX nanoparticles (NPs), was developed by conjugating hydrophilic biodegradable hyaluronic acid (HA) and hydrophobic photoresponsive ruthenium (Ru) complexes, which could encapsulate the chemotherapeutic drug doxrubicin (DOX). Ru-HA@DOX NPs can selectively accumulate at the tumor through the enhanced permeability and retention (EPR) effect and CD44-mediated endocytosis, thus avoiding off-target toxicity during circulation. After 660 nm of irradiation at the tumor site, Ru-HA@DOX NPs, as a "photoactivatable bomb", was split via the photocleavable Ru-N coordination bond to fast release DOX and produce singlet oxygen (1O2) for PDT. In general, Ru-HA@DOX NPs retained its integrity before irradiation and possessed minimal cytotoxicity, while under red-light irradiation, Ru-HA@DOX NPs showed significant cytotoxicity due to the release of DOX and production of 1O2 at the tumor. Chemotherapy-PDT of Ru-HA@DOX NPs resulted in a significant inhibition of tumor growth in A549-tumor-bearing mice and reduced the cardiotoxicity of DOX. Therefore, this study offers a novel CD44-targeted drug-delivery system with on-demand drug release for synergistic chemotherapy-PDT.

Forsythiaside A prevents zymosan A-induced cell migration in neutrophil-differentiated HL-60 cells via PD-1/PD-L1 pathway.

Neutrophils, which account for more than 80% of leukocyte, play an important role in resolution of inflammation. Immune checkpoint molecules could be potential biomarkers in immunosuppression. Forsythiaside A (FTA), a main constituent of Forsythia suspensa (Thunb.) Vahl, provides a very significant anti-inflammatory activity. Here we defined the immunological mechanisms of FTA by taking programmed cell death-1 (PD-1)/programmed cell death-Ligand 1 (PD-L1) pathway into consideration. FTA could inhibited cell migration in HL-60-derived neutrophils in vitro, and this action appeared to be mediated via PD-1/PD-L1 depended JNK and p38 MAPK pathways. In vivo, FTA prevented PD-L1+ neutrophils infiltration and reduced the levels of tumor necrosis factor alpha (TNF-α), interleukin-6 (IL-6), monocyte chemoattractant protein-1 (MCP-1) and interferon-gamma (IFN-γ) after zymosan A-induced peritonitis. PD-1/PD-L1 inhibitor could abolish the suppression of FTA. The expression of inflammatory cytokines and chemokines were positively correlated with PD-L1. Molecular docking showed that FTA could bind to PD-L1. Taken together, FTA might prevent neutrophils infiltration to exert inflammation resolution through PD-1/PD-L1 pathway.

A Novel Diosgenin-Based Liposome Delivery System Combined with Doxorubicin for Liver Cancer Therapy.

As a malignant tumor, liver cancer is mainly treated with chemotherapy, while chemotherapeutic drugs, such as doxorubicin (DOX), may lead to toxicity, drug resistance and poor prognosis. The targeted delivery systems of combining natural products and chemotherapeutic drugs are useful to eliminate cancers with reduced toxicity and increased efficiency. In this study, a diosgenin-based liposome loaded with DOX (Dios-DOX-LP) was developed for synergistic treatment of liver cancer, in which Dios not only replaced cholesterol as the membrane regulator to keep stability of liposomes, but also became the chemotherapy adjuvant of DOX for synergistic treatment. Dios-DOX-LP was characterized by particle size (99.4 ± 6.2 nm), zeta potential (-33.3 ± 2.5 mV), and entrapment efficiency (DOX: 98.77 ± 2.04%, Dios: 87.75 ± 2.93%), which had a good stability and slow-release effect. Compared with commercial DOX liposome (CHOL-DOX-LP), Dios-DOX-LP had an improved anti-tumor effect in vitro and in vivo by inducing the apoptosis and inhibiting the proliferation of the tumor cell, which was 1.6 times better than CHOL-DOX-LP in cytotoxicity, and had 78% of the tumor inhibition rate on tumor-bearing nude mice. Dios-DOX-LP provided a novel idea to achieve synergistic tumor treatment using diosgenin as a liposome material.

Comparative Pharmacokinetics of Cinobufacini Capsule and Injection by UPLC-MS/MS.

Cinobufacini capsule and injection are two different formulations from the same source, obtained from the extraction of the skin of Bufo bufo gargarizans Cantor, which have been approved by the Chinese State Food and Drug Administration (CFDA) for the treatment of various cancers. Our previous study has found that the cinobufacini capsule and injection exhibited different anticancer effects, but their different pharmacokinetic behaviors, which could give a cause of that, have never been reported. So a sensitive and selective method for the simultaneous quantitation of 13 compounds in the rat plasma, including bufothionine, hellebrigenin, bufalin, gamabufotalin, telocinobufagin, cinobufagin, arenobufagin, cinobufotalin, desacetylcinobufotalin, bufotalin, pseudobufarenogin, resibufogenin, and desacetylcinobufagin, was established by using the Agilent 6460 mass spectrometer equipped with an ESI ion source in a multiple-reaction monitoring (MRM) mode. Chromatographic analysis was accomplished in 6 min by using an Agilent SB-C18 column and a mobile phase consisting of 0.1% formic acid in water and acetonitrile in an optimized gradient program at a flow rate of 0.3 ml/min. The correlation coefficients (r) of all analytes ranged from 0.9967 to 0.9996, while their lower limits of quantification ranged from 0.20 to 4.84 ng/ml. The method has been fully verified and applied for the pharmacokinetic difference study of the Cinobufacini capsule and injection in rats. The results showed that nine components could be quantitated in rat plasma samples after the administration of the cinobufacini capsule, while only bufothionine, bufalin, arenobufagin, and pseudobufarenogin could be detected in the cinobufacini injection group. Their pharmacokinetic studies indicated telocinobufagin, bufalin, desacetylcinobufagin, and arenobufagin were predicted as the potential active substances of the Cinobufacini capsule, while bufothionine was considered as a major ingredient in the cinobufacini injection due to its relatively high blood drug exposure. Also, the AUC of the nine components in cinobufacini capsule groups with three different doses showed a similar trend with significant differences, and the exposure increased with the increase of the dose. The pharmacokinetic characteristics of all major ingredients in cinobufacini capsules and injection were of wide variation, which could be used to explain differences in the efficacy of the cinobufacini capsule and injection and infer the pharmacodynamic ingredients of various cinobufacini preparations.

A NIR fluorescent probe for the specific detection of hypochlorite and its application in vitro and in vivo.

It is of great necessity to exploit a real-time, highly selective and sensitive method for hypochlorite (ClO-) detection in both the environment and living systems because of the complex influence of ClO- on health. In this paper, based on the intramolecular charge transfer (ICT) effect, a NIR fluorescent probe (probe DAB) was designed for the accurate detection of ClO-, which produced a fluorescence response to ClO- with high selectivity and rapid response (within 1 min). The probe DAB could determine ClO- over the linear range of 0-80 µM with a low detection limit of 1.46 µM. And the sensing mechanism between the probe and ClO- was verified using HPLC and MS. To further prove its practicability, the probe was applied for detecting ClO- in actual water samples. In addition, owing to its good sensing properties and low cytotoxicity, probe DAB could be expediently applied to visualize ClO- in living cells and zebrafish, and it is expected to be a useful tool for investigating the detailed functions and mechanisms of ClO- in living systems.

All-in-one: Accurate quantification, on-site detection, and bioimaging of sulfite using a colorimetric and ratiometric fluorescent probe in vitro and in vivo.

SO2 and its derivatives (SO32-/HSO3-) are used widely in food, beverages, and pharmaceutical production. However, they could induce multiple diseases in respiratory, nervous, and cardiovascular systems. Although several fluorescent probes have been developed for detecting SO32-/HSO3-, reports on rapid fluorescent probes for the on-site detection of SO2 derivatives are scarce. Herein, a colorimetric and ratiometric fluorescent probe 1 based on the intramolecular charge transfer (ICT) was reported. Probe 1 resulted in a 122 nm blue-shift in fluorescent emission and decrement of absorbance at 500 nm upon the addition of sulfite. Therefore, probe 1 could quantify SO32-/HSO3- using both UV-Vis and fluorescent methods (LOD: UV-Vis method 34 nM; fluorescent method 51 nM). Importantly, probe 1 was used for a rapid (60 s) and convenient (1 step, on-site) measurement of the SO2 derivatives in real samples (LOD: 0.47 µM) using smartphone based on the colorimetric method. The SO32-/HSO3--sensing mechanism was confirmed as the Michael addition reaction. Furthermore, the probe was used for the real-time monitoring of SO32-/HSO3- in A549 cells and zebrafish. In summary, an all-in-one fluorescent probe was successfully developed for the accurate quantification, on-site detection, and bioimaging of SO32-/HSO3-.

A Carrier-Free Folate Receptor-Targeted Ursolic Acid/Methotrexate Nanodelivery System for Synergetic Anticancer Therapy.

PURPOSE: To avoid undefined metabolic mechanisms and to eliminate potential side effects of traditional nanocarriers, new green carriers are urgently needed in cancer treatment. Carrier-free nanoparticles (NPs) based on ursolic acid (UA) have attracted significant attention, but the UA NPs targeting the folate receptor have never been explored. We designed a novel self-assembled UA-Methotrexate (MTX) NPs targeting the folate-receptor and its synergetic anticancer activity was studied in vitro and in vivo. METHODS: UA-MTX NPs were prepared using the solvent precipitation method. Characterization of the UA-MTX NPs preparation was performed using a size analyzer, transmission electron microscopy, and UV-vis spectrophotometry. The in vitro pH-responsive drug release capability of UA-MTX NPs was tested at different pH values. The UA-MTX NPs targeting of folates was determined by comparing the endocytosis rates of cell lines with low or overexpression of the folate receptor (A549 and MCF-7 cells). The cytotoxicity and cell apoptosis of UA-MTX NPs were also studied to determine the in vitro synergistic effects. Combination chemotherapy of UA-MTX NPs in vivo was evaluated using MCF-7 xenografted tumor models. RESULTS: Compared with free UA or MTX, the water solubility of UA-MTX NPs improved significantly. Drug-release from the UA-MTX NPs was faster at pH 5.0 than pH 7.4, suggesting MTX-UA NPs could rapidly release MTX in the acidic conditions of the tumor microenvironment. Confocal laser scanning microscopy revealed the excellent folate receptor targeting of UA-MTX NPs in MCF-7 cells. Cytotoxicity and cell apoptosis results demonstrated greater antiproliferative capacity of UA-MTX NPs than that of free drug in folate receptor overexpressing MCF-7 cells. Anticancer effects in vivo suggested MTX-UA NPs exhibited good biological safety and could enhance antitumor efficacy due to the combination therapy. CONCLUSION: Our findings indicate that the UA-MTX NPs targeting folate-receptors is an efficient strategy for combination chemotherapy.

Design and synthesis of novel 3,4-dihydrocoumarins as potent and selective monoamine oxidase-B inhibitors with the neuroprotection against Parkinson's disease.

The monoamine oxidase-B (MAO-B) inhibitors with neuroprotective effects are better for Parkinson's disease (PD) treatment, due to the complicated pathogenesis of PD. To develop new hMAO-B inhibitors with neuroprotection, a novel series of 3,4-dihydrocoumarins was designed as selective and reversible hMAO-B inhibitors to treat PD. Most compounds showed potent and selective inhibition for hMAO-B over hMAO-A with IC50 values ranging from nanomolar to sub-nanomolar. Among them, compound 4d was the most potent hMAO-B inhibitor (IC50 = 0.37 nM) being about 20783-fold more active than iproniazid, and exhibited the highest selectivity for hMAO-B (SI > 270,270). Kinetic studies revealed that compound 4d was a reversible and competitive inhibitor of hMAO-B. Neuroprotective studies indicated that compound 4d could protect PC12 cells from the damage induced by 6-OHDA and rotenone. Besides, compound 4d did not exhibit acute toxicity at a dose up to 2500 mg/kg (po), and could cross the BBB in parallel artificial membrane permeability assay. More importantly, compound 4d was able to significantly prevent the motor deficits in the MPTP-induced PD model. These results indicate that compound 4d is an effective and promising candidate against PD.

A novel mitochondria-targetted near-infrared fluorescent probe for selective and colorimetric detection of sulfite and its application in vitro and vivo.

Overdoses of SO2 and its derivatives (SO32-/HSO3-) in food or organisms are harmful to health. To detect SO32-/HSO3-, a novel NIR fluorescent probe 1, based upon the intramolecular charge transfer (ICT) mechanism, was developed. This probe was easily synthesized, and gave noticeable colorimetric and linear fluorescence changes at 690 nm after reaction with sulfite from 3.13 to 200 µM. Moreover, probe 1 displayed high sensitivity (LOD = 0.46 µM), excellent selectivity (among 13 kinds of anions and 3 kinds of biothiols) and quick response (within 30 min) towards SO32-/HSO3-. The SO32-/HSO3- sensing mechanism was confirmed as the Michael addition reaction. Furthermore, the probe showed wide applications for measuring SO32-/HSO3- in real samples, including sugar, tap water, wine and traditional Chinese medicine. The probe could also be used to detect SO32-/HSO3- in mitochondria of HepG2 cells and zebrafish, which suggested potential application for monitoring SO2 derivatives in clinical diagnostics.

Rational modulation of coumarin-hemicyanine platform based on OH substitution for higher selective detection of hypochlorite.

To monitor delicate changes of biological HOCl in vivo, a new probe (OH-substituted coumarin-hemicyanine, probe 2) was synthesized for NIR and ratiometric HOCl detection. Selectivity studies indicated that the electron-donating group (OH) substituted on the indolium moiety enhanced the selectivity to detect HOCl. With HOCl, the probe showed a ratiometric fluorescence (I500/I650) with a low detection limit (49.1 nM) and a rapid response (within 2 min). In addition, probe 2 was successfully applied to visualize exogenous and endogenous HOCl in living cells and animals and exhibited a perfect mitochondria target ability. This probe has been further studied as a potential and powerful tool to probe HOCl in arthritis models.

Chromone and donepezil hybrids as new multipotent cholinesterase and monoamine oxidase inhibitors for the potential treatment of Alzheimer's disease.

A series of chromone and donepezil hybrids were designed, synthesized, and evaluated as multipotent cholinesterase (ChE) and monoamine oxidase (MAO) inhibitors for the potential therapy of Alzheimer's disease (AD). In vitro studies showed that the great majority of these compounds exhibited potent inhibitory activity toward BuChE and AChE and clearly selective inhibition for hMAO-B. In particular, compound 5c presented the most balanced potential for ChE inhibition (BuChE: IC50 = 5.24 µM; AChE: IC50 = 0.37 µM) and hMAO-B selectivity (IC50 = 0.272 µM, SI = 247). Molecular modeling and kinetic studies suggested that 5c was a mixed-type inhibitor, binding simultaneously to peripheral and active sites of AChE. It was also a competitive inhibitor, which occupied the substrate and entrance cavities of MAO-B. Moreover, compound 5c could penetrate the blood-brain barrier (BBB) and showed low toxicity to rat pheochromocytoma (PC12) cells. Altogether, these results indicated that compound 5c might be a hopeful multitarget drug candidate with possible impact on Alzheimer's disease therapy.

Design, synthesis and evaluation of novel ferulic acid derivatives as multi-target-directed ligands for the treatment of Alzheimer's disease.

A series of new ferulic acid derivatives were designed, synthesized and evaluated as multi-target inhibitors against Alzheimer's disease. In vitro studies indicated that most compounds showed significant potency to inhibit self-induced ß-amyloid (Aß) aggregation and acetylcholinesterase (AChE), and had good antioxidant activity. Specifically, compound 4g exhibited the potent ability to inhibit cholinesterase (ChE) (IC50, 19.7 nM for hAChE and 0.66 µM for hBuChE) and the good Aß aggregation inhibition (49.2% at 20 µM), and it was also a good antioxidant (1.26 trolox equivalents). Kinetic and molecular modeling studies showed that compound 4g was a mixed-type inhibitor, which could interact simultaneously with the catalytic anionic site (CAS) and the peripheral anionic site (PAS) of AChE. Moreover, compound 4g could remarkably increase PC12 cells viability in hydrogen peroxide-induced oxidative cell damage and Aß-induced cell damage. Finally, compound 4g had good ability to cross the BBB using the PAMPA-BBB assay. These results suggested that compound 4g was a promising multifunctional ChE inhibitor for the further investigation.

A new dicyanoisophorone-based ratiometric and colorimetric near-infrared fluorescent probe for specifically detecting hypochlorite and its bioimaging on a model of acute inflammation.

To explore how hypochlorous acid (HClO) affects human health, a highly sensitive, selective, and trace detection method for hypochlorite (ClO-) is crucial for determining its non-negligible function in both environment and living systems. Herein, a dicyanoisophorone-phenylboronic acid-based novel ratiometric near-infrared fluorescent probe (Probe 1) was designed for the rapid and specific detection of ClO- based on the intramolecular charge transfer (ICT) mechanism. Excess addition of HClO to the Probe 1 solution, 186-times ratio (I652/I582) augment were gained. And this probe provided a colorimetric and ratiometric fluorescence response to ClO- with a high selectivity, a rapid response (within 30 s), and had an extremely low detection limit (15.7 nM). In addition, owing to the good sensing properties and low cytotoxicity of Probe 1, it can be used to expediently visualize exogenous ClO- in HepG2 cells and endogenous ClO- in RAW264.7 macrophage cells. Furthermore, the probe was successfully used for the bioimaging of zebrafish with an acute inflammation. Thus, Probe 1 is a promising vehicle to identify the level of HClO in animals with associated diseases.

A Ratiometric and Colorimetric Hemicyanine Fluorescent Probe for Detection of SO2 Derivatives and Its Applications in Bioimaging.

Based upon the intramolecular charge transfer (ICT) mechanism, a novel ratiometric fluorescent probe EB was developed to detect SO32-/HSO3-. The probe displayed both colorimetric and ratiometric responses toward SO32-/HSO3-. It displayed a quick response (within 60 s), good selectivity and high sensitivity (a detection limit of 28 nM) towards SO32-/HSO3-. The SO32-/HSO3- sensing mechanism was confirmed as the Michael addition reaction by ESI-MS. Moreover, the probe could be applied to measure the level of sulfite in real samples, like sugar and chrysanthemum, and it could also be used to detect SO32-/HSO3- in HepG2 cells through confocal fluorescence microscopy, which proved its practical application in clinical diagnosis.

A near-infrared Nile red fluorescent probe for the discrimination of biothiols by dual-channel response and its bioimaging applications in living cells and animals.

Biothiols, including cysteine (Cys), homocysteine (Hcy), glutathione (GSH) and H2S, play important roles in human physiological processes. However, it is a great difficulty to distinguish biothiols from each other because of their similar chemical properties. Based on Nile red, we have designed and synthesized a near-infrared fluorescent probe for discriminating Cys/Hcy from GSH/H2S by a dual-channel detection method. Using an ether bond, near-infrared Nile red was attached to 7-nitrobenzofurazan to construct the probe. Due to the photo-induced electron transfer, the probe showed almost no fluorescence from the green to red emission band. But upon the addition of Cys (0-150 µM) or Hcy (0-200 µM), the probe exhibited a noteworthy fluorescence "turn-on" signal in two unique emission bands (Green and Red) with a fast response (within 30 min). In contrast, the probe displayed an increase in fluorescence only in the red channel when encountering GSH (0-70 µM) or H2S (0-50 µM), and GSH/H2S could be tested respectively by different response time. The limit of detection was calculated to be 0.09 µM (Cys), 0.30 µM (Hcy), 0.24 µM (GSH), and 0.04 µM (H2S), respectively (based on S/N = 3). The desirable dual-channel detection could be achieved in serum samples and living cells. Moreover, the probe could be applied for bioimaging in mice, which indicated its potential application in the clinic.

Icariside II induces cell cycle arrest and differentiation via TLR8/MyD88/p38 pathway in acute myeloid leukemia cells.

Acute myeloid leukemia (AML) is a devastating hematological malignancy, characterized by differentiation arrest and unscheduled proliferation of immature cells of the myeloid lineage. Inducing AML cell differentiation has emerged as a promising therapeutic strategy for the therapy of AML. Icariside II, an active component of Herba Epimedii, has been well defined to promote osteogenic differentiation. However, the differentiation-inducing effect of Icariside II on AML cells has not been explored. In this study, we investigated the differentiation-inducing effect and underlying mechanism of Icariside II in AML HL-60 and THP-1 cell lines. Icariside II induced G1 phase cell cycle arrest by down-regulating Cyclin-dependent kinases (CDK2, CDK4 and CDK6) and up-regulating Cyclin-dependent kinase inhibitor (p21 and p27). Importantly, Icariside II could induce differentiation of AML cells, accompanied by the up-regulation of Toll-like receptor 8 (TLR8), myeloid differentiation factor 88 (MyD88) and phosphorylated p38. Further study indicated the cell cycle arrest and differentiation induced by Icariside II could be abrogated by TLR8-specific inhibitor CU-CPT9a. Collectively, these findings firstly demonstrate Icariside II induces cell cycle arrest and differentiation of AML cells via activation of TLR8/MyD88/p38 pathway, suggesting Icariside II could be developed into a novel differentiation-inducing agent for AML.

Coumarin-dithiocarbamate hybrids as novel multitarget AChE and MAO-B inhibitors against Alzheimer's disease: Design, synthesis and biological evaluation.

A series of new coumarin-dithiocarbamate hybrids were designed and synthesized as multitarget agents for the treatment of Alzheimer's disease. Most of them showed potent and clearly selective inhibition towards AChE and MAO-B. Among these compounds, compound 8f demonstrated the most potent inhibition to AChE with IC50 values of 0.0068 µM and 0.0089 µM for eeAChE and hAChE, respectively. Compound 8g was identified as the most potent inhibitor to hMAO-B, and it is also a good and balanced inhibitor to both hAChE and hMAO-B (0.114 µM for hAChE; 0.101 µM for hMAO-B). Kinetic and molecular modeling studies revealed that 8g was a dual binding site inhibitor for AChE and a competitive inhibitor for MAO-B. Further studies indicated that 8g could penetrate the BBB and exhibit no toxicity on SH-SY5Y neuroblastoma cells. More importantly, 8g did not display any acute toxicity in mice at doses up to 2500 mg/kg and could reverse the cognitive dysfunction of scopolamine-induced AD mice. Overall, these results highlighted 8g as a potential multitarget agent for AD treatment and offered a starting point for design of new multitarget AChE/MAO-B inhibitors based on dithiocarbamate scaffold.

Reduction-sensitive CD44 receptor-targeted hyaluronic acid derivative micelles for doxorubicin delivery.

INTRODUCTION: A reduction-sensitive CD44-positive tumor-targetable drug delivery system for doxorubicin (DOX) delivery was developed based on hyaluronic acid (HA)-grafted polymers. MATERIALS AND METHODS: HA was conjugated with folic acid (FA) via a reduction-sensitive disulfide linkage to form an amphiphilic polymer (HA-ss-FA). The chemical structure of HA-ss-FA was analyzed by ultraviolet spectroscopy, Fourier transform infrared spectroscopy, and 1H nuclear magnetic resonance (NMR) spectroscopy. The molecular weight of HA-ss-FA was determined by high-performance gel permeation chromatography. Blank HA-ss-FA micelles and DOX-loaded micelles were prepared and characterized. The reduction responsibility, cellular uptake, and in vivo biodistribution of HA-ss-FA micelles were investigated. RESULTS: DOX-loaded micelles were of high encapsulation efficiency (88.09%), high drug-loading content (22.70%), appropriate mean diameter (100-120 nm), narrow size distribution, and negative zeta potential (-6.7 to -31.5 mV). The DOX release from the micelles was significantly enhanced in reduction environment compared to normal environment. The result of in vitro cytotoxicity assay indicated that the blank micelles were of low toxicity and good biocompatibility and the cell viabilities were >100% with the concentration of HA-ss-FA from 18.75 to 600.00 µg/mL. Cellular uptake and in vivo biodistribution studies showed that DOX-loaded micelles were tumor-targetable and could significantly enhance cellular uptake by CD44 receptor-mediated endocytosis, and the cellular uptake of DOX in CD44-positve A549 cells was 1.6-fold more than that in CD44-negative L02 cells. In vivo biodistribution of HA-ss-FA micelles showed that micelles were of good in vivo tumor targetability and the fluorescence of indocyanine green (ICG)-loaded micelles was 4- to 6.6-fold stronger than free ICG within 6 h in HCCLM3 tumor-bearing nude mice. CONCLUSION: HA-ss-FA is a promising nanocarrier with excellent biocompatibility, tumor targetability, and controlled drug release capability for delivery of chemotherapy drugs in cancer therapy.