In vivo targeted delivery of antibodies into cancer cells with pH-responsive cell-penetrating poly(disulfide)s.

Cell-penetrating poly(disulfide)s (CPDs) are promising vehicles for cytosolic delivery of proteins. However, currently available arginine-rich CPD has rarely been reported for systemic delivery due to its "always" positive charge. Herein, we developed pH-responsive CPDIMD that executes tumor targeting delivery via protonation of imidazole groups within the acidic tumor microenvironment.

Efficient separation of photoexcited carriers in a g-C3N4-decorated WO3 nanowire array heterojunction as the cathode of a rechargeable Li-O2 battery.

Utilization of solar energy is very important for alleviating the global energy crisis; however, solar-to-electric energy conversion in a compact battery is a great challenge. High charging overpotential of conventional aprotic Li-O2 batteries still restricts their practical application. Herein, we propose a photo-involved rechargeable Li-O2 battery to not only realize direct solar-to-electric energy conversion/storage but also address the overpotential issue. In this photo-involved battery system, the g-C3N4-decorated WO3 nanowire array (WO3@g-C3N4 NWA) heterojunction semiconductor is used as both the photoelectrode and oxygen electrode. Upon charging under visible-light irradiation, the photoexcited holes and electrons are in situ generated on the WO3@g-C3N4 NWA heterojunction cathode. The fabrication of the heterojunction can distinctly reduce the recombination rate between electrons and holes, while photon-generated carriers are effectively and quickly separated and then migrate under a large current density. The discharge product (Li2O2) can be oxidized to O2 and Li+ with a reduced charging voltage (3.69 V) by the abundant photoexcited holes, leading to high energy efficiency, good cycling stability and excellent rate capability. This newly photo-involved reaction scheme could open new avenues toward the design of advanced solar-to-electric energy conversion and storage systems.

Ginsenoside Rg1 protects against acetaminophen-induced liver injury via activating Nrf2 signaling pathway in vivo and in vitro.

Acetaminophen (APAP) is a worldwide used drug for treating fever and pain. However, APAP overdose is the leading cause of drug-induced liver injury. The purpose of the current study is to evaluate the hepatoprotective effect of ginsenoside Rg1 (Rg1), the main pharmacologically active compounds of Panax ginseng, against APAP-induced acute liver injury, and further to elucidate the involvement of Nrf2 signaling pathway by in vivo and in vitro experiments. Male C57BL/6 mice were treated with Rg1 for 3 days before injection of APAP. Serum and liver tissue samples were collected 6 h later. The results indicated that Rg1 significantly attenuated APAP-induced hepatotoxicity and oxidative stress in a dose-dependent manner. Rg1 effectively enhanced antioxidant and detoxification capacity, which is largely dependent on up-regulating Nrf2 nuclear translocation, reducing Keap1 protein expression and up-regulating Nrf2 target genes including GCLC, GCLM, HO-1, NQO1, Ugt1a1, Ugt1a6, Ugt2b1, Sult2a1, Mrp2, Mrp3 and Mrp4. Furthermore, Rg1 repressed the activities of Cyp2e1, Cyp3a11, Cyp1a2, which are important enzymes in the formation of APAP toxic metabolite N-acetyl-p-benzoquinone imine. However, the changes in transporters and enzymes, as well as ameliorative liver histology induced by Rg1 were abrogated by Nrf2 antagonist all-transretinoic acid in vivo and Nrf2 siRNA in vitro. In conclusion, Rg1 produced hepatoprotective effects against APAP-induced acute liver injury via Nrf2 signaling pathway. Rg1 might be an effective approach for the prevention against acute liver injury.

Protective effects of glutamine on human melanocyte oxidative stress model.

BACKGROUND: Vitiligo is a disorder caused by the loss of the melanocyte activity on melanin pigment generation. Studies show that oxidative-stress induced apoptosis in melanocytes is closely related to the pathogenesis of vitiligo. Glutamine is a well known antioxidant with anti-apoptotic effects, and is used in a variety of diseases. However, it is unclear whether glutamine has an antioxidant or anti-apoptotic effect on melanocytes. AIMS: The aim of this study was to investigate the protective effects of glutamine on a human melanocyte oxidative stress model. METHODS: The oxidative stress model was established on human melanocytes using hydrogen peroxide. The morphology and viability of melanocytes, levels of oxidants [reactive oxygen species and malondialdehyde], levels of antioxidants [superoxide dismutase and glutathione-S-transferase], and apoptosis-related indicators (caspase-3, bax and bcl-2) were examined after glutamine exposure at various concentrations. Expressions of nuclear factor-E2-related factor 2, heme oxygenase-1, and heat shock protein 70 were detected using western blot technique after glutamine exposure at various concentrations. RESULTS: Our results demonstrate that pre-treatment and post-treatment with glutamine promoted melanocyte viability, increased levels of superoxide dismutase, glutathione-S-transferase and bcl-2, decreased levels of reactive oxygen species, malondialdehyde, bax and caspase-3, and enhanced nuclear factor-E2-related factor 2, heme oxygenase-1, and heat shock protein 70 expression in a dose dependent manner. The effect of pre-treatment was more significant than post-treatment, at the same concentration. LIMITATIONS: The mechanisms of glutamine activated nuclear factor-E2-related factor 2 antioxidant responsive element signaling pathway need further investigation. CONCLUSIONS: Glutamine enhances the antioxidant and anti-apoptotic capabilities of melanocytes and protects them against oxidative stress.

Protective effects of yangonin from an edible botanical Kava against lithocholic acid-induced cholestasis and hepatotoxicity.

Accumulation of toxic bile acids in liver could cause cholestasis and liver injury. The purpose of the current study is to evaluate the hepatoprotective effect of yangonin, a product isolated from an edible botanical Kava against lithocholic acid (LCA)-induced cholestasis, and further to elucidate the involvement of farnesoid X receptor (FXR) in the anticholestatic effect using in vivo and in vitro experiments. The cholestatic liver injury model was established by intraperitoneal injections of LCA in C57BL/6 mice. Serum biomarkers and H&E staining were used to identify the amelioration of cholestasis after yangonin treatment. Mice hepatocytes culture, gene silencing experiment, real-time PCR and Western blot assay were used to elucidate the mechanisms underlying yangonin hepatoprotection. The results indicated that yangonin promoted bile acid efflux and reduced hepatic uptake via an induction in FXR-target genes Bsep, Mrp2 expression and an inhibition in Ntcp, all of which are responsible for bile acid transport. Furthermore, yangonin reduced bile acid synthesis through repressing FXR-target genes Cyp7a1 and Cyp8b1, and increased bile acid metabolism through an induction in gene expression of Sult2a1, which are involved in bile acid synthesis and metabolism. In addition, yangonin suppressed liver inflammation through repressing inflammation-related gene NF-κB, TNF-α and IL-1ß. In vitro evidences showed that the changes in transporters and enzymes induced by yangonin were abrogated when FXR was silenced. In conclusions, yangonin produces protective effect against LCA-induced hepatotoxity and cholestasis due to FXR-mediated regulation. Yangonin may be an effective approach for the prevention against cholestatic liver diseases.

Computational discovery and experimental verification of farnesoid X receptor agonist auraptene to protect against cholestatic liver injury.

Recently obeticholic acid (OCA) which is a farnesoid X receptor (FXR) agonist was approved by FDA to treat cholestatic liver diseases, which provided us a novel therapeutic strategy against cholestasis. Herein, we used a novel computational strategy with two-dimensional virtual screening for FXR agonists. For the first time, we found that auraptene (AUR), a natural product, can activate FXR to exert hepatoprotective effect against cholestatic liver injury in vivo and in vitro. Importantly, AUR was found to significantly decrease the mortality of cholestatic mice. Dynamic change analysis of bile acids and gene analysis revealed that AUR promoted bile acid efflux from liver into intestine via an induction in FXR-target genes Bsep and Mrp2 expression, and reduced hepatic uptake through an inhibition in Ntcp. Furthermore, AUR reduced bile acid synthesis through repressing FXR-target genes Cyp7a1 and Cyp8b1, and increased bile acid metabolism through an induction in Sult2a1. In addition, AUR promoted liver repair through an induction in liver regeneration-related gene, and suppressed liver inflammation through repressing inflammation-related gene NF-κB, TNF-α, IL-1ß and IL-6. However, the changes in these genes and protein, as well as ameliorative liver histology induced by AUR were abrogated by FXR antagonist guggulsterone in vivo and FXR siRNA in vitro. These findings suggest that AUR may be an effective approach for the prevention against cholestatic liver diseases.

Synthesis of 3-alkyl- or 3-allenyl-2-amidobenzofurans via electrophilic cyclization of o-anisole-substituted ynamides with carbocations.

A facile carbocation-induced electrophilic cyclization reaction has been developed for the synthesis of 3-alkyl- or 3-allenyl-2-amidobenzofurans from o-anisole-substituted ynamides and diarylmethanol or 1,1-diarylprop-2-yn-1-ol.

Synthesis of allenamides by Pd-catalyzed coupling of 3-alkoxycarbonyloxy ynamides or 1-alkoxycarbonyloxy allenamides with arylboronic acids.

An efficient palladium-catalyzed method is reported for the synthesis of multi-substituted allenamides by Suzuki-Miyaura cross-coupling reaction between easily prepared 3-alkoxycarbonyloxy ynamides or 1-alkoxycarbonyloxy allenamides and arylboronic acids.

Synthesis of δ-carbolines via a Pd-catalyzed sequential reaction from 2-iodoanilines and N-tosyl-enynamines.

A facile Pd-catalyzed sequential reaction has been developed for the synthesis of δ-carbolines from 2-iodoanilines and N-tosyl-enynamines. This protocol involves Larock heteroannulation/elimination/electrocyclization/oxidative aromatization cascade sequences and allows access to multisubstituted δ-carbolines in moderate to good yields.