Neuroprotective Effects of Tetrahydroxystilbene Glucoside against Rotenone-Induced Toxicity in PC12 Cells.

To investigate the mechanism of the protective effect of tetrahydroxystilbene glucoside (TSG) on nerve cells, an injury model induced by rotenone in PC12 cells was constructed. Cell viability was detected by using cell counting kit-8 (CCK8) assay. Apoptosis was detected by using flow cytometry. The mitochondrial membrane potential (MMP) was detected by using the fluorescent probe JC-1. Generation of reactive oxygen species (ROS) in PC12 cells was determined using the 5-(and-6)-chloromethyl-2',7'-dichlorodihydrofluorescein diacetate acetyl ester (CM-H2DCFDA) probe. Protein expression in PC12 cells was detected using Western blotting. The results showed that TSG (20-100 µM) attenuated the cytotoxic effects of rotenone on PC12 cells. TSG pretreatment attenuated the apoptosis rate, the degradation of poly(ADP-ribose)polymerase (PARP) and the activation of cleaved caspase 3, which was induced by rotenone. TSG can significantly reduce the effect of rotenone on the reduction of MMP and the expression of cytoC in the cytosolic fraction. TSG attenuated rotenone-induced de-phosphorylation and mitochondrial translocation of cofilin, as well as rotenone-induced accumulation of ROS. The Western blot results showed that ROT could decrease the expression level of phosphorylated (p)-Glycogen synthase kinase-3ß (GSK)-3ß and p-AKT, and TSG could weaken these effects of rotenone. In addition, TSG increased the expression level of nuclear factor-E2-related factor 2 (Nrf2) in the nuclear fraction. These results suggest that TSG could protect PC12 cells against rotenone through multiple pathways. Thus, TSG has the potential to become a novel neuroprotective agent.

Dual-modified PCL-PEG nanoparticles for improved targeting and therapeutic efficacy of docetaxel against colorectal cancer.

Polycaprolactone-poly (ethylene glycol) block copolymer (PCL-PEG) based nanoparticles were prepared for the intravenous administration of docetaxel (DTX). PCL-PEG-Tyr and PCL-PEG-Ang were synthesized by using tyrosine (Tyr) and angiopep-2 (Ang) as coupling ligands, and dual-modified PCL-PEG-based nanoparticles (PCL-PEG-Tyr/Ang) were prepared. The physicochemical properties, in vitro drug release, in vitro cytotoxicity, in vitro cellular uptake efficiency, in vivo biodistribution and in vivo antitumor efficacy of PCL-PEG-based nanoparticles were investigated. The PCL-PEG-based nanoparticles were spherical with a mean diameter of 100 nm and high encapsulation efficiencies (> 85%). The results of in vitro drug release showed that the PCL-PEG-based nanoparticles loaded with DTX had sustained-release characteristics. For in vitro cytotoxicity tests, the dual-modified PCL-PEG-based nanoparticles (PCL-PEG-Tyr/Ang) demonstrated the minimum IC50 value (2.94 µg/mL) compared with other PCL-PEG-based nanoparticles. In addition, the cellular uptake of coumarin-6 (C6) in HT29 cells was observed and determined in the PCL-PEG-Tyr/Ang nanoparticles group, which was significantly higher than that in the other PCL-PEG-based groups and C6 solution group. The results of in vivo imaging showed that dual-modified PCL-PEG nanoparticles had better tumor targeting than the other PCL-PEG-based nanoparticles. In the HT29 tumor-xenografted nude mice model, DTX-loaded PCL-PEG-Tyr/Ang nanoparticles also had a significantly higher inhibitory efficacy on tumor growth than Taxotere®-treated group. These results indicated that the dual-modified PCL-PEG-based nanoparticles (PCL-PEG-Tyr/Ang) could be a promising anticancer drug delivery system.

Bifunctional Furfuryl Cations Strategy: Three-Component Synthesis of Enamidyl Triazoles.

A new multicomponent synthesis of functionalized enamidyl triazoles starting from simple and readily available starting materials is described. A simple treatment of a dichloromethane solution of an azide, amine, and 5-bromo-2-furylcarbinol with a Lewis acid provides the enamidyl triazole in good to high yield. A triple domino sequence, formal [3+2] cycloaddition/ring-opening/amidation, is involved in this new skeleton-generating reaction.

Tumor-associated macrophages in anti-PD-1/PD-L1 immunotherapy for hepatocellular carcinoma: recent research progress.

Hepatocellular carcinoma (HCC) is one of the cancers that seriously threaten human health. Immunotherapy serves as the mainstay of treatment for HCC patients by targeting the programmed cell death protein 1/programmed cell death 1 ligand 1 (PD-1/PD-L1) axis. However, the effectiveness of anti-PD-1/PD-L1 treatment is limited when HCC becomes drug-resistant. Tumor-associated macrophages (TAMs) are an important factor in the negative regulation of PD-1 antibody targeted therapy in the tumor microenvironment (TME). Therefore, as an emerging direction in cancer immunotherapy research for the treatment of HCC, it is crucial to elucidate the correlations and mechanisms between TAMs and PD-1/PD-L1-mediated immune tolerance. This paper summarizes the effects of TAMs on the pathogenesis and progression of HCC and their impact on HCC anti-PD-1/PD-L1 immunotherapy, and further explores current potential therapeutic strategies that target TAMs in HCC, including eliminating TAMs in the TME, inhibiting TAMs recruitment to tumors and functionally repolarizing M2-TAMs (tumor-supportive) to M1-TAMs (antitumor type).

Mechanism of Lethal Skin Toxicities Induced by Epidermal Growth Factor Receptor Inhibitors and Related Treatment Strategies.

Epidermal growth factor receptor (EGFR) inhibitors are widely used to treat various types of cancers such as non-small cell lung cancer, head and neck cancer, breast cancer, pancreatic cancer. Adverse reactions such as skin toxicity, interstitial lung disease, hepatotoxicity, ocular toxicity, hypomagnesemia, stomatitis, and diarrhea may occur during treatment. Because the EGFR signaling pathway is important for maintaining normal physiological skin function. Adverse skin reactions occurred in up to 90% of cancer patients treated with EGFR inhibitors, including common skin toxicities (such as papulopustular exanthemas, paronychia, hair changes) and rare fatal skin toxicities (e.g., Stevens-Johnson syndrome, toxic epidermal necrolysis, acute generalized exanthematous pustulosis). This has led to the dose reduction or discontinuation of EGFR inhibitors in the treatment of cancer. Recently, progress has been made about research on the skin toxicity of EGFR inhibitors. Here, we summarize the mechanism of skin toxicity caused by EGFR inhibitors, measures to prevent severe fatal skin toxicity, and provide reference for medical staff how to give care and treatment after adverse skin reactions.

The Application of Peptides in Glioma: A Novel Tool for Therapy.

BACKGROUND: Glioma is the most aggressive and lethal tumor of the central nervous system. Due to the cellular heterogeneity, the invasiveness, and blood-brain barrier (BBB), current therapeutic approaches, such as chemotherapy and radiotherapy, are poorly to obtain great antitumor efficacy. However, peptides, a novel type of therapeutic agent, displayed excellent ability in the tumor, which becomes a new molecule for glioma treatment. METHODS: We review the current knowledge on peptides for the treatment of glioma through a PubMed-based literature search. RESULTS: In the treatment of glioma, peptides can be used as (i) decoration on the surface of the delivery system, facilitating the distribution and accumulation of the anti-tumor drug in target site; (ii) anti-tumor active molecules, inhibiting the growth of glioma and reducing solid tumor volume; (iii) immune-stimulating factor, and it activating immune cells in the tumor microenvironment or recruiting immune cells to the tumor for breaking out the immunosuppression by glioma cells. CONCLUSION: The application of peptides has revolutionized the treatment of glioma, which based on targeting, penetrating, anti-tumor activities and immunostimulatory. Moreover, better outcomes have been discovered in combining different kinds of peptides rather than a single one. Until now, more and more preclinical studies have been developed with multifarious peptides, which shows promising results in vitro or vivo with the model of glioma.

Cyclovirobuxine D Induces Apoptosis and Mitochondrial Damage in Glioblastoma Cells Through ROS-Mediated Mitochondrial Translocation of Cofilin.

BACKGROUND: Cyclovirobuxine D (CVBD), a steroidal alkaloid, has multiple pharmacological activities, including anti-cancer activity. However, the anti-cancer effect of CVBD on glioblastoma (GBM) has seldom been investigated. This study explores the activity of CVBD in inducing apoptosis of GBM cells, and examines the related mechanism in depth. METHODS: GBM cell lines (T98G, U251) and normal human astrocytes (HA) were treated with CVBD. Cell viability was examined by CCK-8 assay, and cell proliferation was evaluated by cell colony formation counts. Apoptosis and mitochondrial superoxide were measured by flow cytometry. All protein expression levels were determined by Western blotting. JC-1 and CM-H2DCFDA probes were used to evaluate the mitochondrial membrane potential (MMP) change and intracellular ROS generation, respectively. The cell ultrastructure was observed by transmission electron microscope (TEM). Colocalization of cofilin and mitochondria were determined by immunofluorescence assay. RESULTS: CVBD showed a greater anti-proliferation effect on the GBM cell lines, T98G and U251, than normal human astrocytes in dose- and time-dependent manners. CVBD induced apoptosis and mitochondrial damage in GBM cells. We found that CVBD led to mitochondrial translocation of cofilin. Knockdown of cofilin attenuated CVBD-induced apoptosis and mitochondrial damage. Additionally, the generation of ROS and mitochondrial superoxide was also induced by CVBD in a dose-dependent manner. N-acetyl-L-cysteine (NAC) and mitoquinone (MitoQ) pre-treatment reverted CVBD-induced apoptosis and mitochondrial damage. MitoQ pretreatment was able to block the mitochondrial translocation of cofilin caused by CVBD. CONCLUSIONS: Our data revealed that CVBD induced apoptosis and mitochondrial damage in GBM cells. The underlying mechanism is related to mitochondrial translocation of cofilin caused by mitochondrial oxidant stress.

Bovine Serum Albumin Nanoparticle-Mediated Delivery of Sorafenib for Improving Hepatocellular Carcinoma Therapy.

Hepatocellular carcinoma (HCC) is the most common primary malignancy of the liver. The majority of patients with HCC are diagnosed with advanced-stage disease. Sorafenib is a frontline therapy drug approved by the Food and Drug Administration for advanced HCC. However, the poor aqueous solubility of sorafenib limits its applications. The present study aimed to overcome this limitation of sorafenib. Thus, bovine serum albumin (BSA)-based nanoparticles were developed to encapsulate hydrophobic sorafenib. The resultant sorafenib-loaded BSA nanoparticles (Sf-BSA-NPs) were thoroughly characterized for size distribution, encapsulation efficiency and morphology. Previous studies on HepG2 cells in vitro have demonstrated that Sf-BSA-NPs exhibit remarkable superiority to free sorafenib in cytocompatibility, cytotoxicity and proapoptotic effect. The results of the present study demonstrated that Sf-BSA-NPs were effective in improving aqueous solubility, and enhanced drug cytotoxicity, suggesting its therapeutic potential for HCC.

Recent Developments in Pharmacological Effect, Mechanism and Application Prospect of Diazeniumdiolates.

Nitric oxide (NO) is a simple structured and unstable free radical molecule, which participates in the regulation of many pathophysiological processes. It functions both as a second messenger and as an endogenous neurotransmitter. Diazeniumdiolates (NONOates) are a series of compounds containing the functional parent nuclear structure of [N(O)NO]-, which are the most widely studied NO donors. NONOates are unstable and easy to release NO in physiological conditions. The biomedical applications and drug development of NO donor have attracted the scientists' attention in recent years. In this review, recent advances in NONOates research are highlighted in terms of chemical structures, molecular characteristics, pharmacological effects, and biomedical application prospects.

Fe(III)-Catalyzed Aerobic Intramolecular N-N Coupling of Aliphatic Azides with Amines.

An Fe(III)-catalyzed intramolecular N-N coupling of aliphatic azidoamines that forms diverse five- and six-membered semisaturated diazoheterocycles using air as an oxidant is reported, providing an alternative to hydrazine-based methods. Mechanistic studies suggest that a N-radical induced intramolecular homolytic substitution (SH2) is involved in ring closure. The power of this N-N bond-forming method is also demonstrated by using it as the final step in a total synthesis of (-)-newbouldine.

Lactoferrin-modified rotigotine nanoparticles for enhanced nose-to-brain delivery: LESA-MS/MS-based drug biodistribution, pharmacodynamics, and neuroprotective effects.

INTRODUCTION: Efficient delivery of rotigotine into the brain is crucial for obtaining maximum therapeutic efficacy for Parkinson's disease (PD). Therefore, in the present study, we prepared lactoferrin-modified rotigotine nanoparticles (Lf-R-NPs) and studied their biodistribution, pharmacodynamics, and neuroprotective effects following nose-to-brain delivery in the rat 6-hydroxydopamine model of PD. MATERIALS AND METHODS: The biodistribution of rotigotine nanoparticles (R-NPs) and Lf-R-NPs after intranasal administration was assessed by liquid extraction surface analysis coupled with tandem mass spectrometry. Contralateral rotations were quantified to evaluate pharmacodynamics. Tyrosine hydroxylase and dopamine transporter immunohistochemistry were performed to compare the neuroprotective effects of levodopa, R-NPs, and Lf-R-NPs. RESULTS: Liquid extraction surface analysis coupled with tandem mass spectrometry analysis, used to examine rotigotine biodistribution, showed that Lf-R-NPs more efficiently supplied rotigotine to the brain (with a greater sustained amount of the drug delivered to this organ, and with more effective targeting to the striatum) than R-NPs. The pharmacodynamic study revealed a significant difference (P<0.05) in contralateral rotations between rats treated with Lf-R-NPs and those treated with R-NPs. Furthermore, Lf-R-NPs significantly alleviated nigrostriatal dopaminergic neurodegeneration in the rat model of 6-hydroxydopamine-induced PD. CONCLUSION: Our findings show that Lf-R-NPs deliver rotigotine more efficiently to the brain, thereby enhancing efficacy. Therefore, Lf-R-NPs might have therapeutic potential for the treatment of PD.

Tf ligand-receptor-mediated exenatide-Zn2+ complex oral-delivery system for penetration enhancement of exenatide.

Safe and effective oral delivery of peptide is a challenge. Here, we used exenatide and zinc ions (Zn2+) to form a complex to explore a meaningful oral-targeted drug-delivery system. Polyethylene glycol-poly(lactic acid-co-glycolic acid) (PEG-PLGA) was used to prepare nanoparticles (NPs) to escape the degradation caused by gastrointestinal enzymes. Transferrin (Tf) was used as a targeting group. PEG-PLGA-NPs and Tf-modified exenatide-Zn2+-loaded NPs (Tf-PEG-PLGA-NPs) were uniformly sized spheres according to transmission electron microscopy. The results of pharmacodynamic and pharmacokinetic investigations in vivo were consistent with in vitro studies using Caco-2 cells. Tf enhanced NPs transport in cell-uptake and transmembrane-transport experiments. Our results showed that the relative bioavailability of Tf-exenatide-Zn2+-NPs was higher than that of exenatide-Zn2+-NPs. The relative bioavailability of Tf-exenatide-Zn2+-NPs versus subcutaneous injection of exenatide was 6.45%. This was a preliminary exploration of the oral administration of exenatide, that data from which can be used for future investigations.

Preparation and evaluation of injectable Rasagiline mesylate dual-controlled drug delivery system for the treatment of Parkinson's disease.

A microsphere-gel in situ forming implant (MS-Gel ISFI) dual-controlled drug delivery system was applied to a high water-soluble small-molecule compound Rasagiline mesylate (RM) for effective treatment of Parkinson's disease. This injectable complex depot system combined an in situ phase transition gel with high drug-loading and encapsulation efficiency RM-MS prepared by a modified emulsion-phase separation method and optimized by Box-Behnken design. It was evaluated for in vitro drug release, in vivo pharmacokinetics, and in vivo pharmacodynamics. We found that the RM-MS-Gel ISFI system showed no initial burst release and had a long period of in vitro drug release (60 days). An in vivo pharmacokinetic study indicated a significant reduction (p < .01) in the initial high plasma drug concentration of the RM-MS-Gel ISFI system compared to that of the single RM-MS and RM-in situ gel systems after intramuscular injection to rats. A pharmacodynamic study demonstrated a significant reduction (p < .05) in 6-hydroxydopamine-induced contralateral rotation behavior and an effective improvement (p < .05) in dopamine levels in the striatum of the lesioned side after 28 days in animals treated with the RM-MS-Gel ISFI compared with that of animals treated with saline. MS-embedded in situ phase transition gel is superior for use as a biodegradable and injectable sustained drug delivery system with a low initial burst and long period of drug release for highly hydrophilic small molecule drugs.

Trastuzumab- and Fab' fragment-modified curcumin PEG-PLGA nanoparticles: preparation and evaluation in vitro and in vivo.

INTRODUCTION: Nanoparticles (NPs) modified with bio-ligands represent a promising strategy for active targeted drug delivery to tumour. However, many targeted ligands, such as trastuzumab (TMAB), have high molecular weight, limiting their application for targeting. In this study, we prepared Fab' (antigen-binding fragments cut from TMAB)-modified NPs (Fab'-NPs) with curcumin (Cur) as a model drug for more effective targeting of human epidermal growth factor receptor 2 (HER2/ErbB2/Neu), which is overexpressed on breast cancer cells. MATERIAL AND METHODS: The release kinetics was conducted by dialysis bags. The ability to kill HER2-overexpressing BT-474 cells of Fab'-Cur-NPs compared with TMAB-Cur-NPs was conducted by cytotoxicity experiments. Qualitative and quantitative cell uptake studies using coumarin-6 (fluorescent probe)-loaded NPs were performed by fluorescence microscopy and flow cytometry. Pharmacokinetics and biodistribution experiments in vivo were assessed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). RESULTS: The release kinetics showed that both Fab'-Cur-NPs and TMAB-Cur-NPs provided continuous, slow release of curcumin for 72 h, with no significant difference. In vitro cytotoxicity experiments showed that Fab'-Cur-NPs manifested prominent ability to kill HER2-overexpressing BT-474 cells compared with TMAB-Cur-NPs. Qualitative and quantitative cell uptake studies indicated that the accumulation of Fab'-NPs was greater than that of TMAB-NPs in BT-474 (HER2+) cells; However, there was no significant difference in MDA-MB-231 (HER2-) cells. Pharmacokinetics and biodistribution experiments in vivo demonstrated that the half-life (t1/2) and area under the blood concentration-time curve (AUC0-t) of Fab'-Cur-NPs increased 5.30-fold and 1.76-fold relative to those of TMAB-Cur-NPs, respectively. Furthermore, the tumor accumulation of Fab'-Cur-NPs was higher than that of TMAB-Cur-NPs. CONCLUSION: Fab' fragment has greater capacity than the intact antibody to achieve tumor targeting through NP-based delivery.

Conversion of 2-furylcarbinols with alkyl or aryl azides to highly functionalized 1,2,3-triazoles via cascade formal [3 + 2] cycloaddition/ring-opening.

A Lewis acid promoted cascade cycloaddition/ring-opening of 2-furylcarbinols with alkyl or aryl azides is described. The reaction features an initial formal [3 + 2] cycloaddition to form a trisubstitued triazole motif, followed by a ring opening of furan to generate the (E)-configuration of the enone. A wide range of highly functionalized triazoles is expediently and efficiently synthesized in a highly step-economical manner.