Synthesis and evaluation of alkoxy-substituted enamides against influenza A virus in vitro and in vivo.

Alkoxy-substituted enamides are often used as synthetic intermediates due to their special reactivity. To the best our knowledge, the biological activity of alkoxy-substituted amines has never been reported so far. We have synthesized a series of alkoxy-substituted enamides to study their anti-influenza A virus activity in vitro and in vivo. Among these compounds, compound E-2o had the best antiviral activity (EC50 = 2.76 ± 0.67 µM) and low cytotoxicity (CC50 = 662.87 ± 24.85 µM). The mechanism of action of this compound was preliminarily explored by us. It alleviated the cytopathic effects and cell death caused by different subtypes of influenza A virus. Different drug delivery methods and timed dosing experiments had shown that E-2o had the best therapeutic effect and mainly played a role in the early stages of virus replication. The expansion of influenza viruses in cells was inhibited by reducing ROS accumulation, cell apoptosis, and autophagy. Alkoxy-substituted enamide E-2o reduced the production of interferon and other pro-inflammatory factors in the RIG-Ⅰ pathway and its downstream NF-κB was induced by influenza A virus in vitro and in vivo. It avoided damage in the mice which was caused by excessive inflammatory factors. In addition, the weight loss and lung lesion damage in mice caused by influenza virus were improved by compound E-2o. Therefore, Alkoxy-substituted enamide E-2o could inhibit the replication of influenza viruses in vivo and in vitro, and has the potential to be developed into a drug for treating influenza.

Discovery of a novel Coumarin-Dihydroquinoxalone derivative MY-673 as a tubulin polymerization inhibitor capable of inhibiting the ERK pathway with potent anti-gastric cancer activities.

As a class of microtubule targeting agents, colchicine binding site inhibitors (CBSIs) are considered as promising drug candidates for cancer therapy. However, due to adverse reactions, there are currently no CBSIs approved by FDA for cancer treatment. Therefore, extensive efforts are still encouraged to find novel CBSIs with different chemical structures and better anticancer efficacies. In this work, we designed and synthesized a new coumarin-dihydroquinoxalone derivative, MY-673, and evaluated its anticancer potency in vitro and in vivo. We confirmed that MY-673 was a potent CBSI that it not only inhibited tubulin polymerization, but also exhibited significant inhibitory potency on the growth of 13 cancer cells with IC50 values from 11.7 nM to 395.9 nM. Based on the results of kinase panel screening, MY-673 could inhibit ERK (extracellular regulated protein kinases) pathways-related kinases. We further confirmed that MY-673 could inhibit ERK signaling pathway in MGC-803 and HGC-27 cells, and then affected the expression level of SMAD4 protein in TGF-ß (transforming growth factor ß) /SMAD (small mother against decapentaplegic) signaling pathway using the western blotting assay. In addition, compound MY-673 could effectively inhibit cell proliferation, migration and induce cell apoptosis. We also further confirmed the in vivo efficacy of MY-673 in inhibiting tumor growth using the MGC-803 xenograft tumor model. At 20 mg/kg, the TGI rate was 85.9%, and it did not cause obvious toxicity to the main organs of mice. Together, the results we report here indicated that MY-673 was a promising CBSI for cancer treatment, which was capable of inhibiting the ERK pathway with potent antiproliferative activities in vitro and in vivo.

Tubulin degradation: Principles, agents, and applications.

The microtubule system plays an important role in the mitosis and growth of eukaryotic cells, and it is considered as an appealing and highly successful molecular target for cancer treatment. In fact, microtubule targeting agents, such as paclitaxel and vinblastine, have been approved by FDA for tumor therapy, which have achieved significant therapeutic effects and sales performance. At present, microtubule targeting agents mainly include microtubule-destabilizing agents, microtubule-stabilizing agents, and a few tubulin degradation agents. Although there are few reports about tubulin degradation agents at present, tubulin degradation agents show great potential in overcoming multidrug resistance and reducing neurotoxicity. In addition, some natural drugs could specifically degrade tubulin in tumor cells, but have no effect in normal cells, thus showing a good biosafety profile. Therefore, tubulin degradation agents might exhibit a better application. Currently, some small molecules have been designed to promote tubulin degradation with potent antiproliferative activities, showing the potential for cancer treatment. In this work, we reviewed the reports on tubulin degradation, and focused on the degradation mechanism and important functional groups of chemically synthesized compounds, hoping to provide help for the degradation design of tubulin.

Suppression of JNK/ERK dependent autophagy enhances Jaspine B derivative-induced gastric cancer cell death via attenuation of p62/Keap1/Nrf2 pathways.

Gastric cancer is one of the most common cancers with few effective treatments, a new treatment agent is desperately needed. C-2, a Jaspine B derivative, has shown anti-cancer efficacy in gastric cancer cells. The anti-cancer mechanism, however, remains unknown. As a result, we investigate the anti-cancer effect and the underlying mechanism of C-2 in gastric cancer cells. The results showed that C-2 selectively reduced the proliferation of gastric cancer cells when compared to normal epithelial gastric cells. Western blotting and flow cytometry further demonstrated that Caspase9 is involved in causing cell death. Meanwhile, C-2 triggered autophagy in gastric cancer cells, inhibition of which with LY294002 can enhance the anti-proliferative activity of C-2. Next, we found that C-2 triggered autophagy through activating JNK/ERK, and that inhibitors of these proteins exacerbated C-2 induced cell death. Mechanically, enhanced phosphorylation of JNK/ERK elevated Beclin-1 by disturbing Beclin-1/Bcl-xL or Beclin-1/Bcl-2 complexes, resulting in autophagy and up-regulation of p62. Finally, p62 binds Keap1 competitively to release Nrf2, boosting Nrf2 translocation from the cytoplasm to the nucleus and triggering expression of Nrf2 target genes, so enhancing survival. C-2 inhibited the growth of gastric cancer cells, while JNK/ERK dependent autophagy antagonized C-2 induced cell growth inhibition through p62/Keap1/Nrf2 pathway.

Inhibition of Lipopolysaccharide-Induced Inflammatory and Oxidative Responses by Trans-cinnamaldehyde in C2C12 Myoblasts.

Background: Trans-cinnamaldehyde (tCA), a bioactive component found in Cinnamomum cassia, has been reported to exhibit anti-inflammatory and antioxidant effects, but its efficacy in muscle cells has yet to be found. In this study, we investigated the inhibitory effect of tCA on inflammatory and oxidative stress induced by lipopolysaccharide (LPS) in C2C12 mouse skeletal myoblasts. Methods: To investigate the anti-inflammatory and antioxidant effects of tCA in LPS-treated C2C12 cells, we measured the levels of pro-inflammatory mediator, cytokines, and reactive oxygen species (ROS). To elucidate the mechanism underlying the effect of tCA, the expression of genes involved in the expression of inflammatory and oxidative regulators was also investigated. We further evaluated the anti-inflammatory and antioxidant efficacy of tCA against LPS in the zebrafish model. Results: tCA significantly inhibited the LPS-induced release of pro-inflammatory mediators and cytokines, which was associated with decreased expression of their regulatory genes. tCA also suppressed the expression of Toll-like receptor 4 (TLR4) and myeloid differentiation factor, and attenuated the nuclear translocation of nuclear factor-kappa B (NF-κB) and the binding of LPS to TLR4 on the cell surface in LPS-treated C2C12 cells. Furthermore, tCA abolished LPS-induced generation of ROS and expression levels of ROS producing enzymes, NADPH oxidase 1 (NOX1) and NOX2. However, tCA enhanced the activation of nuclear translocation of nuclear factor-E2-related factor 2 (Nrf2) and the expression of heme oxygenase-1 (HO-1) in LPS-stimulated C2C12 myoblasts. In addition, tCA showed strong protective effects against NO and ROS production in LPS-injected zebrafish larvae. Conclusions: Our findings suggest that tCA exerts its inhibitory ability against LPS-induced inflammatory and antioxidant stress in C2C12 myoblasts by targeting the TLR4/NF-κB, which might be mediated by the NOXs and Nrf2/HO-1 pathways.

Discovery of N-aryl sulphonamide-quinazoline derivatives as anti-gastric cancer agents in vitro and in vivo via activating the Hippo signalling pathway.

Hippo signalling pathway plays a crucial role in tumorigenesis and cancer progression. In this work, we identified an N-aryl sulphonamide-quinazoline derivative, compound 9i as an anti-gastric cancer agent, which exhibited potent antiproliferative ability with IC50 values of 0.36 µM (MGC-803 cells), 0.70 µM (HCT-116 cells), 1.04 µM (PC-3 cells), and 0.81 µM (MCF-7 cells), respectively and inhibited YAP activity by the activation of p-LATS. Compound 9i was effective in suppressing MGC-803 xenograft tumour growth in nude mice without obvious toxicity and significantly down-regulated the expression of YAP in vivo. Compound 9i arrested cells in the G2/M phase, induced intrinsic apoptosis, and inhibited cell colony formation in MGC-803 and SGC-7901 cells. Therefore, compound 9i is to be reported as an anti-gastric cancer agent via activating the Hippo signalling pathway and might help foster a new strategy for the cancer treatment by activating the Hippo signalling pathway regulatory function to inhibit the activity of YAP.

Yeast Synthetic Biology for the Production of Lycium barbarum Polysaccharides.

The fruit of Lycium barbarum L. (goji berry) is used as traditional Chinese medicine, and has the functions of immune regulation, anti-tumor, neuroprotection, anti-diabetes, and anti-fatigue. One of the main bioactive components is L. barbarum polysaccharide (LBP). Nowadays, LBP is widely used in the health market, and it is extracted from the fruit of L. barbarum. The planting of L. barbarum needs large amounts of fields, and it takes one year to harvest the goji berry. The efficiency of natural LBP production is low, and the LBP quality is not the same at different places. Goji berry-derived LBP cannot satisfy the growing market demands. Engineered Saccharomyces cerevisiae has been used for the biosynthesis of some plant natural products. Recovery of LBP biosynthetic pathway in L. barbarum and expression of them in engineered S. cerevisiae might lead to the yeast LBP production. However, information on LBP biosynthetic pathways and the related key enzymes of L. barbarum is still limited. In this review, we summarized current studies about LBP biosynthetic pathway and proposed the strategies to recover key enzymes for LBP biosynthesis. Moreover, the potential application of synthetic biology strategies to produce LBP using engineered S. cerevisiae was discussed.

Drug Discovery Targeting Focal Adhesion Kinase (FAK) as a Promising Cancer Therapy.

FAK is a nonreceptor intracellular tyrosine kinase which plays an important biological function. Many studies have found that FAK is overexpressed in many human cancer cell lines, which promotes tumor cell growth by controlling cell adhesion, migration, proliferation, and survival. Therefore, targeting FAK is considered to be a promising cancer therapy with small molecules. Many FAK inhibitors have been reported as anticancer agents with various mechanisms. Currently, six FAK inhibitors, including GSK-2256098 (Phase I), VS-6063 (Phase II), CEP-37440 (Phase I), VS-6062 (Phase I), VS-4718 (Phase I), and BI-853520 (Phase I) are undergoing clinical trials in different phases. Up to now, there have been many novel FAK inhibitors with anticancer activity reported by different research groups. In addition, FAK degraders have been successfully developed through "proteolysis targeting chimera" (PROTAC) technology, opening up a new way for FAK-targeted therapy. In this paper, the structure and biological function of FAK are reviewed, and we summarize the design, chemical types, and activity of FAK inhibitors according to the development of FAK drugs, which provided the reference for the discovery of new anticancer agents.

Hemistepsin A protects human keratinocytes against hydrogen peroxide-induced oxidative stress through activation of the Nrf2/HO-1 signaling pathway.

Hemistepsin A, a sesquiterpene lactone compound isolated from Hemistepta lyrata, has been identified a variety of pharmacological actions including anti-hepatotoxic, anti-inflammatory and anti-cancer activities. Nevertheless, the antioxidant effects of hemistepsin A and the underlying mechanisms have not been investigated properly. Therefore, in the present study, we investigated the protective effect of hemistepsin A against oxidative stress in HaCaT human keratinocytes. The results demonstrated that hemistepsin A suppressed 500 µM hydrogen peroxide (H2O2)-induced cytotoxicity and DNA damage by blocking ROS accumulation. 10 µM Hemistepsin A also prevented apoptosis by preventing the mitochondrial dysfunction and the cytosolic release of cytochrome c, reducing the rate of Bax/Bcl-2 expression, and decreasing the activation of caspase-9 and caspase-3, suggesting that hemistepsin A protected cells from H2O2-induced mitochondria-mediated apoptosis. In addition, hemistepsin A markedly promoted the activation of nuclear factor-erythroid-2-related factor 2 (Nrf2), which was associated with the enhanced expression and activity of heme oxygenase-1 (HO-1) in the presence of 500 µM H2O2. However, inhibiting the expression of HO-1 by artificially blocking the expression of Nrf2 or HO-1 using siRNA significantly eliminated the protective effect of hemistepsin A, indicating that hemistepsin A activates the Nrf2/HO-1 signaling pathway in HaCaT cells to protect against oxidative stress. Therefore, these results suggest that hemistepsin A may be useful as a potential therapeutic agent against various oxidative stress-related skin diseases.

GSK-3ß-Targeting Fisetin Promotes Melanogenesis in B16F10 Melanoma Cells and Zebrafish Larvae through ß-Catenin Activation.

Fisetin is found in many fruits and plants such as grapes and onions, and exerts anti-inflammatory, anti-proliferative, and anticancer activity. However, whether fisetin regulates melanogenesis has been rarely studied. Therefore, we evaluated the effects of fisetin on melanogenesis in B16F10 melanoma cell and zebrafish larvae. The current study revealed that fisetin slightly suppressed in vitro mushroom tyrosinase activity; however, molecular docking data showed that fisetin did not directly bind to mushroom tyrosinase. Unexpectedly, fisetin significantly increased intracellular and extracellular melanin production in B16F10 melanoma cells regardless of the presence or absence of α-melanocyte stimulating hormone (α-MSH). We also found that the expression of melanogenesis-related genes such as tyrosinase and microphthalmia-associated transcription factor (MITF), were highly increased 48 h after fisetin treatment. Pigmentation of zebrafish larvae by fisetin treatment also increased at the concentrations up to 200 µM and then slightly decreased at 400 µM, with no alteration in the heart rates. Molecular docking data also revealed that fisetin binds to glycogen synthase kinase-3ß (GSK-3ß). Therefore, we evaluated whether fisetin negatively regulated GSK-3ß, which subsequently activates ß-catenin, resulting in melanogenesis. As expected, fisetin increased the expression of ß-catenin, which was subsequently translocated into the nucleus. In the functional assay, FH535, a Wnt/ß-catenin inhibitor, significantly inhibited fisetin-mediated melanogenesis in zebrafish larvae. Our data suggested that fisetin inhibits GSK-3ß, which activates ß-catenin, resulting in melanogenesis through the revitalization of MITF and tyrosinase.

7-Deoxynarciclasine shows promising antitumor efficacy by targeting Akt against hepatocellular carcinoma.

Akt is a promising therapeutic target for cancer treatment. In our study, we have identified that 7-deoxynarciclasine (7-DONCS) is a potential inhibitor of Akt, which results in the repression of multiple oncogenic processes in hepatocellular carcinoma (HCC). We have found that 7-DONCS suppresses the growth of HCC by inducing the apoptotic and autophagic capacities, as well as by inhibiting epithelial-mesenchymal transition (EMT) in vitro and in vivo. Pretreatment of cells with specific autophagy inhibitor (Bafilomycin A1) or knockdown of endogenous LC­3B by siRNA strongly enhences 7­DONCS­regulated apoptosis and EMT. Consequently, we have found that 7-DONCS selectively inhibits phospho-Akt (Ser473), and subsequent molecular docking reveals that 7-DONCS directly binds to the C-terminal domain of Akt. Overexpressing Akt significantly blocks these effects via 7-DONCS in HCC cells. Furthermore, 7-DONCS, by targeting Akt, exhibits a promising therapeutic effect in orthotopic hepatocellular tumors. Finally, higher p-Akt expression is associated with poor prognosis, and higher level of Akt was positively correlated with the enrichment of both apoptosis and autophagy downregulation, and EMT upregulation in HCC patients. These studies suggest that 7-DONCS serves as an attractive drug candidate by targeting Akt for future HCC therapy.

TRAIL attenuates sulforaphane-mediated Nrf2 and sustains ROS generation, leading to apoptosis of TRAIL-resistant human bladder cancer cells.

Tumor necrosis factor-related apoptosis inducing ligand (TRAIL) can preferentially initiate apoptosis in malignant cells with minimal toxicity to normal cells. Unfortunately, many human cancer cells are refractory to TRAIL-induced apoptosis through many unknown mechanisms. Here, we report that TRAIL resistance can be reversed in human bladder cancer cell lines by treatment with sulforaphane (SFN), a well-known chemopreventive isothiocyanate in various cruciferous vegetables. Combined treatment with SFN and TRAIL (SFN/TRAIL) significantly induced apoptosis concomitant with activation of caspases, loss of mitochondrial membrane potential (MMP), Bid truncation, and induction of death receptor 5. Transient knockdown of Bid prevented collapse of MMP induced by SFN/TRAIL, consequently reducing apoptotic effects. Furthermore, SFN increased both the generation of reactive oxygen species (ROS) and the activation of nuclear factor erythroid 2-related factor 2 (Nrf2), which is an anti-oxidant enzyme. Interestingly, TRAIL effectively suppressed SFN-mediated nuclear translocation of Nrf2, and the period of ROS generation was more extended compared to that of treatment with SFN alone. In addition, silencing of Nrf2 increased apoptosis in cells treated with SFN/TRAIL; however, blockade of ROS generation inhibited apoptotic activity. These data suggest that SFN-induced ROS generation promotes TRAIL sensitivity and SFN can be used for the management of TRAIL-resistant cancer.

Discovery of novel jaspine B analogues as autophagy inducer.

A series of 2-alkylaminomethyl jaspine B analogues were synthesized and evaluated for their cytotoxic effects on human lung adenocarcinoma, breast cancer, and prostate cancer cell lines and a mouse melanoma cell line. Most of the compounds exhibited moderate to good activity against the cancer cell lines. Compound 7f showed the best overall cytotoxicity on PC-3 cells (IC50 = 0.85 µM). Further mechanistic studies revealed that compound 7f induced marked changes in PC-3 cell morphology, disrupted the mitochondrial membrane potential, and increased expression of the autophagy proteins beclin-1, LC3, and P62.

Piceatannol-Induced Apoptosis Is Reversed by N-Acetyl-L-cysteine through Restoration of XIAP Expression.

Piceatannol, a naturally occurring stilbene derivative mainly found in grapes, possesses apoptotic activity in various cancer cell lines, in addition to potent antioxidant activity. In the current study, we showed that piceatannol exhibits potent cytotoxic effects in all tested leukemia cell lines (THP-1, HL-60, U937, and K562). These effects were accompanied by induction of DNA damage, an increase in the proportion of cells in the sub-G1 phase of the cell cycle, and inhibition of reactive oxygen species (ROS) generation. However, N-acetyl-L-cysteine (NAC), a strong ROS scavenger, significantly inhibited piceatannol-induced apoptosis, suggesting that piceatannol-induced apoptosis does not occur via inhibition of ROS generation. Piceatannol also resulted in a significant increase in mitochondrial depolarization, along with a decline in Bcl-2 expression, which was not restored by NAC. Conversely, ectopic Bcl-2 overexpression moderately inhibited piceatannol-induced apoptosis. Furthermore, piceatannol strongly inhibited X-linked inhibitor of apoptosis protein (XIAP) expression, which was restored by NAC. A transient knockdown of XIAP significantly increased piceatannol-induced apoptosis in the presence of NAC, suggesting that XIAP downregulation increases piceatannol-induced apoptosis, and that NAC could reverse this effect by increasing XIAP expression. Taken together, these results suggest that piceatannol induces apoptosis in human leukemia cell lines by downregulating XIAP expression, regardless of antioxidant activity.

A new brominated chalcone derivative suppresses the growth of gastric cancer cells in vitro and in vivo involving ROS mediated up-regulation of DR5 and 4 expression and apoptosis.

A new series of 20 brominated chalcone derivatives were designed, synthesized, and investigated for their effects against the growth of four cancer cell lines (EC109, SKNSH, HepG2, MGC803). Among them, compound 19 which given chemical name of H72, was the most potent one on gastric cancer cell lines (i.e. MGC803, HGC27, SGC7901) with IC50s ranged from 3.57 to 5.61µM. H72 exhibited less cytotoxicity to non-malignant gastric epithelial cells GES-1. H72 treatment of MGC803 and HGC27 induced generation of reactive oxygen species (ROS) leading to activation of caspase 9/3 cascade and mitochondria mediated apoptosis. H72 also up-regulated the expression of DR5, DR4 and BimEL, and down-regulated the expression of Bid, Bcl-xL, and XIAP. N-acetyl cysteine (NAC), a ROS scavenger completely blocked these effects of H72 in MGC803 cells. Intraperitoneal administration of H72 significantly inhibited the growth of MGC803 cells in vivo in a xenograft mouse model without observed toxicity. These results indicated that H72 is a lead brominated chalcone derivate and deserves further investigation for prevention and treatment of gastric cancer.

Neddylation-dependent LSD1 destabilization inhibits the stemness and chemoresistance of gastric cancer.

Histone lysine-specific demethylase 1 (LSD1) expression has been evaluated in multiple tumors, including gastric cancer (GC). However, the mechanisms underlying LSD1 dysregulation in GC remain largely unclear. In this study, neural precursor cell-expressed developmentally down-regulated protein 8 (NEDD8) was identified to be conjugated to LSD1 at K63 by ubiquitin-conjugating enzyme E2 M (UBE2M), and this neddylated LSD1 could promote LSD1 ubiquitination and degradation, leading to a decrease of GC cell stemness and chemoresistance. Herein, our findings revealed a novel mechanism of LSD1 neddylation and its contribution to decreasing GC cell stemness and chemoresistance. Taken together, our findings may whistle about the future application of neddylation inhibitors.

Microcrystallization Effects in Borosilicate Bioactive Glasses: Controllable Release of Bioactive Elements and In Vitro Degradation Properties.

Borosilicate bioactive glasses exhibit excellent bioactivity and degradation properties; however, they suffer from the rapid release of bioactive elements at the initial stage of their degradation. Excessive local concentrations (such as those of B) can affect cell proliferation. Moreover, the degradation and mineralization ability of these glasses deteriorate at the later stages. Aiming to balance the release of bioactive elements during the whole process, herein, a borosilicate bioactive glass 18SiO2-6Na2O-8K2O-8MgO-22CaO-2P2O5-36B2O3 (mol%) was prepared using the melting method. Further, the effects of microcrystallization on the release of bioactive elements and in vitro degradation were studied. Results show that after heat treatment at temperatures over 620 °C, multiple microcrystalline phases, including Ca2SiO4, CaB2O4, and CaMgB2O5, form in the glass. The glass samples heat-treated within the range of 620-640 °C undergo appropriate devitrification degrees, decelerating the rate of pH increase of the immersion solution during the initial stage in comparison to those treated at lower temperatures. This results in a more continuous release of all bioactive elements and allows better control of the overall degradation. Contrarily, the more extensive devitrification degrees of glass samples heat-treated at higher temperatures reverse the pH increase and degradation trends. Since bone marrow mesenchymal stem cells and mouse embryonic osteoblast cells are pH-sensitive, inducing a suitable degree of devitrification proved to favor cell viability and enhance the mineralization capacity. Thus, different microcrystallization degrees provide new approaches for controlling the degradation and release of bioactive elements, resulting in the simultaneous enhancement of biosafety and bioactivity.

A review of progress in o-aminobenzamide-based HDAC inhibitors with dual targeting capabilities for cancer therapy.

Histone deacetylases, as a new class of anticancer targets, could maintain homeostasis by catalyzing histone deacetylation and play important roles in regulating the expression of target genes. Due to the fact that simultaneous intervention with dual tumor related targets could improve treatment effects, researches on innovative design of dual-target drugs are underway. HDAC is known as a "sensitizer" for the synergistic effects with other anticancer-target drugs because of its flexible structure design. The synergistic effects of HDAC inhibitor and other target inhibitors usually show enhanced inhibitory effects on tumor cells, and also provide new strategies to overcome multidrug resistance. Many research groups have reported that simultaneously inhibiting HDAC and other targets, such as tubulin, EGFR, could enhance the therapeutic effects. The o-aminobenzamide group is often used as a ZBG group in the design of HDAC inhibitors with potent antitumor effects. Given the prolonged inhibitory effects and reduced toxic side effects of HDAC inhibitors using o-aminobenzamide as the ZBG group, the o-aminobenzamide group is expected to become a more promising alternative to hydroxamic acid. In fact, o-aminobenzamide-based dual inhibitors of HDAC with different chemical structures have been extensively prepared and reported with synergistic and enhanced anti-tumor effects. In this work, we first time reviewed the rational design, molecular docking, inhibitory activities and potential application of o-aminobenzamide-based HDAC inhibitors with dual targeting capabilities in cancer therapy, which might provide a reference for developing new and more effective anticancer drugs.

Design, synthesis, and anti-respiratory syncytial virus potential of novel 3-(1,2,3-triazol-1-yl)furoxazine-fused benzimidazole derivatives.

Respiratory syncytial virus (RSV) is a major cause of serious lower respiratory tract infections in infants, children, and older persons. Currently, the only approved anti-viral chemotherapeutic drug for RSV treatment is ribavirin aerosol; however, its significant toxicity has led to restricted clinical use. In a previous study, we developed various benzimidazole derivatives against RSV. In this study, we synthesised 3-azide substituted furoxazine-fused benzimidazole derivatives by sulfonylation and azide substitution of the 3-hydroxyl group of the furoxazine-fused benzimidazole derivatives. Subsequently, a series of 3-(1,2,3-triazol-1-yl)-substituted furoxazine-fused benzimidazole derivatives were synthesised using the classical click reaction. Biological evaluations of the target compounds indicated that compound 4a-2 had higher activity against RSV (EC50 = 12.17 µM) and lower cytotoxicity (CC50 = 390.64 µM). Compound 4a-2 exerted anti-viral effects against the RSV Long strain by inhibiting apoptosis and the elevation of reactive oxygen species (ROS) and inflammatory factors caused by viral infection in vitro. Additionally, the clinical symptoms of the virus-infected mice were markedly relieved, and the viral load in the lung tissues was dramatically decreased. The biosafety profile of compound 4a-2 was also favourable, showing no detectable adverse effects on any of the major organs in vivo. These findings underscore the potential of compound 4a-2 as a valuable therapeutic option for combating RSV infections while also laying the foundation for further research and development in the field.

Nrf2-mediated activation of HO-1 is required in the blocking effect of compound K, a ginseng saponin metabolite, against oxidative stress damage in ARPE-19 human retinal pigment epithelial cells.

Background: The beneficial effects of compound K (CK) on different chronic diseases have been shown to be at least related to antioxidant action. Nevertheless, since its antioxidant activity in human retinal pigment epithelial (RPE) cells is still unknown, here we investigated whether CK alleviates oxidative stress-stimulated damage in RPE ARPE-19 cells. Methods: The cytoprotective consequence of CK in hydrogen peroxide (H2O2)-treated cells was evaluated by cell viability, DNA damage, and apoptosis assays. Fluorescence analysis and immunoblotting were performed to investigate the inhibitory action of CK on reactive oxygen species (ROS) production and mitochondrial dysfunction. Results: H2O2-promoted cytotoxicity, oxidative stress, DNA damage, mitochondrial impairment, and apoptosis were significantly attenuated by CK in ARPE-19 cells. Furthermore, nuclear factor erythroid 2-related factor 2 (Nrf2) phosphorylation level and its shuttling to the nucleus were increased, which was correlated with upregulated activation of heme oxygenase-1 (HO-1). However, zinc protoporphyrin, a blocker of HO-1, significantly abrogated the preventive action of CK in H2O2-treated ARPE-19 cells. Conclusion: This study indicates that activation of Nrf2/HO-1 signaling by CK plays an important role in rescuing ARPE-19 cells from oxidative cellular damage.