[Application effect of a dual release system of androgen and its antagonist in the repair of full-thickness burn wounds in mice]

Objective: To explore the optimal ratio of dihydrotestosterone and hydroxyflutamide (hereinafter referred to as DH), construct a dual release system of androgen and its antagonist, and analyze the application effect of this system in the repair of full-thickness burn wounds in mice. Methods: This study was an experimental study. The HaCaT cells were divided into blank group (without drug culture), low baseline group, medium baseline group, and high baseline group according to the random number table (the same grouping method below), and the last three groups of cells were cultured by adding three different ratios of DH. Under a medium ratio, the mass of dihydrotestosterone in the three baseline groups from low to high was 1.4, 2.8, and 4.0 µg, respectively, and the mass of hydroxyflutamide was 1.2, 1.6, and 2.0 µg, respectively. On this basis, under a small ratio, the mass of dihydrotestosterone was reduced by half and the mass of hydroxyflutamide was increased by half; under a large ratio, the mass of dihydrotestosterone was increased by half and the mass of hydroxyflutamide was reduced by half. After culture of 2 days, the cell proliferation level was detected by cell counting kit 8 (n=4). Sixteen 6-8-week-old male BALB/c mice were used to establish a full-thickness burn wound on the back and divided into blank group, small ratio group, medium ratio group, and large ratio group, with 4 mice in each group. On post injury day (PID) 7, normal saline containing different ratios of DH was locally dropped to the wounds of mice in the last three groups of mice (the total mass of DH in the three ratio groups from small to large was 127.5, 165.0, and 202.5 µg, respectively, and the mass ratios of dihydrotestosterone to hydroxyflutamide (hereinafter referred to as drug mass ratio) were 8∶9, 8∶3, and 8∶1, respectively), afterwards, the administration was repeated every 48 hours until PID 27; normal saline was dropped to the wound of mice in blank group at the aforementioned time points. The wound healing status on PID 0 (immediately), 7, 14, 21, and 28 was observed, and the wound healing rates on PID 7, 14, 21, and 28 were calculated (n=4). On PID 28, the wound tissue was taken, which was stained with hematoxylin and eosin for observing re-epithelialization and with Masson for observing collagen fibers, and the proportion of collagen fibers was analyzed (n=3). Twenty 6-8-week-old male BALB/c mice were used to establish a full-thickness burn wound on the back and divided into ordinary scaffold group, small proportion scaffold group, medium proportion scaffold group, and large proportion scaffold group (with 5 mice in each group). On PID 7, the wound was continuously dressed with a polycaprolactone scaffold without drug and a polycaprolactone scaffold containing DH with a drug mass ratio of 1∶3, 1∶1, or 3∶1 (i.e. the dual release system of androgen and its antagonist, with total mass of DH being about 1.7 mg) prepared by using electrospinning technology until the end of the experiment. Histopathological analyses of tissue (n=3) at the same time points as those in the previous animal experiment were performed. On PID 7 and 14, the wound exudates were collected and the relative abundance of bacterial communities was analyzed using 16S ribosomal RNA high-throughput sequencing (n=3). Results: After culture of 2 days, under a small ratio, the proliferation levels of HaCaT cells in low baseline group and high baseline group were significantly higher than the level in blank group (P<0.05). As the time after injury prolonged, the wounds of all four groups of mice continued to shrink. On PID 14, the wound healing rate of mice in large ratio group was 72.5% (61.7%, 75.1%), which was close to 53.3% (49.5%, 64.4%) in blank group (P>0.05); the wound healing rates of mice in small and medium ratio groups were 74.2% (71.0%, 84.2%) and 70.4% (65.1%, 74.4%), respectively, which were significantly higher than the rate in blank group (with both Z values being -2.31, P<0.05). On PID 21, the wound healing rate of mice in small ratio group was significantly higher than that in blank group (Z=-2.31, P<0.05). On PID 28, the wounds of mice in the three ratio groups were completely re-epithelialized and the epidermis was thicker than that in blank group; compared with that in blank group, the collagen fiber content in the wound tissue of mice in the three ratio groups was higher and arranged more orderly, and the proportions of collagen fibers in the wound tissue of mice in small and large ratio groups were significantly increased (P<0.05). On PID 28, the wounds of mice in ordinary scaffold group were partially epithelialized, while the wounds of mice in the three proportion scaffold groups were almost completely epithelialized. Among them, the wounds of mice in small proportion scaffold group had the thickest epidermis. The proportion of collagen fibers in the wound tissue of mice in small proportion scaffold group was significantly increased compared with that in ordinary scaffold group (P<0.05). On PID 7, the bacterial communities with high relative abundance in the wound exudation of mice in the four groups included bacteria of Corynebacterium, Staphylococcus, and Rhodococcus. On PID 14, the bacterial communities with high relative abundance in the wound exudation of mice in the four groups included bacteria of Stenotrophomonas, Rhodococcus, and Staphylococcus, and the number of bacterial species in the wound exudation of mice in the three proportion scaffold groups was more than that in ordinary scaffold group. Conclusions: When the drug mass ratio is relatively small, DH has the effect of promoting the proliferation of HaCaT cells. The ratio of 8∶9 is the optimal mass ratio of dihydrotestosterone to hydroxyflutamide, and DH with this mass ratio can promote re-epithelialization and collagen deposition of full-thickness burn wounds in mice, and promote wound healing. The constructed dual release system of androgen and its antagonist with DH in a 1∶3 drug mass ratio contributes to the re-epithelialization and collagen deposition of the full-thickness burn wounds in mice, and can improve the diversity of wound microbiota.

Discovery of 4-(N-dithiobenzyl piperazine)-1,8-naphthalimide as a potent multi-target antitumor agent with good efficacy, limited toxicity, and low resistance

A series of 4-(N-dithiobenzyl piperazine)-1,8-naphthalimide derivatives 4-6 were designed, synthesized, and evaluated as novel multi-target antitumor agents. 3-(4,5-Dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) results showed that compounds 5j, 5k, and 6j exhibited superior in vitro antiproliferative activity in MGC-803, HepG-2, SKOV-3, and T24 cancer cell lines and the cisplatin-resistant cell line A549/DDP. HepG-2, SKOV-3, and T24 xenograft assay results revealed that compounds 5j, 5k, and 6j exhibited good antitumor effects compared with amonafide. The pathology results indicated that compound 5j exhibited the least comprehensive toxicity among the three compounds, identifying compound 5j as a good candidate antitumor agent with good efficacy, limited toxicity, and low resistance. Compound 5j was thus chose for further antitumor mechanism investigation. Results from the omics research, confocal immunofluorescence, Western blot, transmission electron microscopy, and flow cytometry indicated that compound 5j exerted antitumor effects through multiple mechanisms, including ferroptosis, autophagy, apoptosis, and cell cycle arrest. These results suggest that screening novel 1,8-naphthalimide-based antitumor agents for good efficacy, limited toxicity, and low resistance based on a multi-target drug strategy is feasible.

Synthesis and Biological Evaluation of Novel 2-Amino-1,4-Naphthoquinone Amide-Oxime Derivatives as Potent IDO1/STAT3 Dual Inhibitors with Prospective Antitumor Effects

Indoleamine-2,3-dioxygenase 1 (IDO1) and signal transducer and activator of transcription 3 (STAT3) have emerged as significant targets in the tumor microenvironment for cancer therapy. In this study, we synthesized three novel 2-amino-1,4-naphthoquinone amide-oxime derivatives and identified them as dual inhibitors of IDO1 and STAT3. The representative compound NK3 demonstrated effective binding to IDO1 and exhibited good inhibitory activity (hIDO1 IC50 = 0.06 μM), leading to its selection for further investigation. The direct interactions between compound NK3 and IDO1 and STAT3 proteins were confirmed through surface plasmon resonance analysis. A molecular docking study of compound NK3 revealed key interactions between NK3 and IDO1, with the naphthoquinone-oxime moiety coordinating with the heme iron. In the in vitro anticancer assay, compound NK3 displayed potent antitumor activity against selected cancer cell lines and effectively suppressed nuclear translocation of STAT3. Moreover, in vivo assays conducted on CT26 tumor-bearing Balb/c mice and an athymic HepG2 xenograft model revealed that compound NK3 exhibited potent antitumor activity with low toxicity relative to 1-methyl-L-tryptophan (1-MT) and doxorubicin (DOX). Overall, these findings provided evidence that the dual inhibitors of IDO1 and STAT3 may offer a promising avenue for the development of highly effective drug candidates for cancer therapy.

Discovery of novel sulfonamide chromone-oxime derivatives as potent indoleamine 2,3-dioxygenase 1 inhibitors

A series of chromone-oxime derivatives containing piperazine sulfonamide moieties were designed, synthesized and evaluated for their inhibitory activities against IDO1. These compounds displayed moderate to good inhibitory activity against IDO1 with IC₅₀ values in low micromolar range. Among them, compound 10m bound effectively to IDO1 with good inhibitory activities (hIDO1 IC₅₀ = 0.64 μM, HeLa IDO1 IC₅₀ = 1.04 μM) and were selected for further investigation. Surface plasmon resonance analysis confirmed the direct interaction between compound 10m and IDO1 protein. Molecular docking study of the most active compound 10m revealed key interactions between 10m and IDO1 in which the chromone-oxime moiety coordinated to the heme iron and formed several hydrogen bonds with the porphyrin ring of heme and ALA264, consistent with the observation by UV-visible spectra that 10m induced a Soret peak shift from 403 to 421 nm. Moreover, compound 10m exhibited no cytotoxicity at its effective concentration in MTT assay. Consistently, in vivo assays results demonstrated that 10m displayed potent antitumor activity with low toxicity in CT26 tumor-bearing Balb/c mice, in comparison with 1-methyl-l-tryptophan (1-MT) and 4-amino-N-(3-chloro-4-fluorophenyl)-N'-hydroxy-1,2,5-oxadiazole-3-carboximidamide (IDO5L). In brief, the results suggested that chromone-oxime derivatives containing sulfonamide moieties might serve as IDO1 inhibitors for the development of new antitumor agents.

Ursolic acid-piperazine-dithiocarbamate ruthenium(II) polypyridyl complexes induced necroptosis in MGC-803 cells

Three ursolic acid-piperazine-dithiocarbamate ruthenium(II) polypyridyl complexes Ru1-Ru3 were designed and synthesized for evaluating antitumor activity. All the complexes exhibited high in vitro cytotoxicity against MGC-803, T24, HepG2, CNE2, MDA-MB-231, MCF-7, A549, and A549/DDP cell lines. Ru1, Ru2, and Ru3 were 11, 8 and 10 times, respectively, more active than cisplatin against A549/DDP. An in vivo study on MGC-803 xenograft mouse models demonstrated that representative Ru2 exhibited an effective inhibitory effect on tumor growth, showing stronger antitumor activity than cisplatin. Biological investigations suggested that Ru2 entered MGC-803 cells by a clathrin-mediated endocytic pathway, initially localizing in the lysosomes and subsequently escaping and localizing in the mitochondria. Mitochondrial swelling resulted in vacuolization, which induced vacuolation-associated cell death and necroptosis with the formation of necrosomes (RIP1-RIP3) and the uptake of propidium iodide. These results demonstrate that the potential of Ru2 as a chemotherapeutic agent to kill cancer cells via a dual mechanism represents an alternative way to eradicate apoptosis-resistant forms of cancer.

Discovery of 2H-chromone-4-one based sulfonamide derivatives as potent retinoic acid receptor-related orphan receptor γt inverse agonists

Retinoic acid receptor related orphan receptor γt (RORγt), identified as the essential functional regulator of IL-17 producing Th17 cells, is an attractive drug target for treating autoimmune diseases. Starting from the reported GSK2981278 (Phase II), we structurally modified and synthesized a series of 2H-chromone-4-one based sulfonamide derivatives as novel RORγt inverse agonists, which significantly improved their human metabolic stabilities while maintaining a potent RORγt inverse agonist profile. Efforts in reducing the lipophilicity and improving the LLE values led to the discovery of c9, which demonstrated potent RORγt inverse agonistic activity and consistent metabolic stability. During in vivo studies, oral administration of compound c9 exhibited a robust and dose-dependent inhibition of IL-17A cytokine expression and significantly lessened the skin inflammatory symptoms in the mouse imiquimod-induced skin inflammation model. Docking analysis of the binding mode revealed that c9 can suitably occupy the active pocket, and the introduction of the morpholine pyridine group can interact with Leu396, His479, and Cys393. Thus, compound c9 was selected as a preclinical compound for treating Th17-driven autoimmune diseases.

Alternative wetting boundary condition for the chemical-potential-based free-energy lattice Boltzmann model

The free-energy lattice Boltzmann (LB) method is a multiphase LB approach based on the thermodynamic theory. Compared with traditional free-energy LB models, which employ a nonideal thermodynamic pressure tensor, the chemical-potential-based free-energy LB model has attracted much attention in recent years as it avoids computing the thermodynamic pressure tensor and its divergence. In this paper, we propose an improved wetting boundary condition for the chemical-potential-based free-energy LB model. Different from the original wetting boundary condition in the literature, the improved wetting boundary condition utilizes a surface chemical potential that is compatible with the chemical potential of the fluid domain. Accordingly, the thermodynamic consistency of the chemical-potential-based free-energy LB model can be retained by the improved wetting boundary condition. Numerical simulations are performed for droplets resting on flat and cylindrical surfaces with different contact angles. The numerical results show that the improved wetting boundary condition yields more reasonable results and the maximum spurious velocities are found to be smaller by 2 ∼ 3 orders of magnitude than those produced by the original wetting boundary condition.

Anti-proliferative effects of diterpenoids from Sagittaria trifolia L. tubers on colon cancer cells by targeting the NF-κB pathway

A new labdane-type diterpenoid, ent-19-ol-13-epi-manoyl oxide,19-undecane ester, together with ten known diterpenes, were isolated from the ethanolic crude extract of the fresh tubers of Sagittaria trifolia L. The chemical structures of these compounds were determined by extensive 2-D NMR experiments and by comparison with the data reported in the literature. These compounds showed different inhibitory effects on various human cancer cells. Among these, compound 11 exhibited potential inhibition effects against human colon cancer cells. Moreover, flow cytometry demonstrated that compound 11 arrested the cell cycle at the G1 phase and induced cellular apoptosis, accompanied by mitochondrial membrane potential reduction. Mechanistic studies revealed that treatment with compound 11 inhibited IKKα/β phosphorylation and IκBα phosphorylation, which subsequently caused the blockage of NF-κB p65 phosphorylation and nuclear translocation. Compound 11 also inhibited the expression of c-Myc, Cyclin D1, and Bcl-2, the downstream targets of NF-κB. Therefore, our findings provided insight into the anticancer components of Sagittaria trifolia L. tubers, which could facilitate their utilization as functional food ingredients.

[Effect of amoxicillin on the enamel mineralization of SD rats]

Objective: To determine whether amoxicillin had an effect on the enamel mineralization of SD rats. Methods: Eighteen SD rats were randomly divided into three groups. The rats in the control group were given distilled water. The rats in two experimental groups were administered 50 or 100 mg/kg amoxicillin by intragastric administration from day 3 to day 17 after birth. The general condition, the structure of liver and kidney, the enamel surface changes of mandibular first molars and incisors were observed. The changes of Ca/P ratio on enamel surface were analyzed by X-ray energy dispersive spectrometer (EDS). The surface morphology after phosphoric acid treatment was examined by scanning electron microscopy (SEM). Histological changes in the ameloblasts of mandibular incisors were analyzed by hematoxylin and eosin (HE) staining. Results: Compared with the control group, the general conditions as well as liver and kidney structures of SD rats in 50 and 100 mg amoxicillin groups had no significant differences. There was no obvious chalky changes on the first mandibular molars of SD rats in each group. All the incisors in 50 and 100 mg groups showed different degrees of chalkiness in the labial incisal 1/3 enamel. X-ray EDS analysis showed that the Ca/P ratios of occlusal and incisal 1/3 enamel in 50 and 100 mg groups (occlusal 1/3 of mandibular first molars: 1.51±0.03 and 1.52±0.02, incisal 1/3 of mandibular incisors: 1.46±0.01 and 1.43±0.01) was significantly lower than that in the control group (occlusal 1/3 of mandibular first molars: 1.67±0.41, incisal1/3 of mandibular incisors: 1.73±0.07) (P<0.05). However, there was no significant differences in the cervical 1/3 Ca/P ratio of mandibular first molars and incisors among the three groups (mandibular first molars: 1.56±0.04 for control group, 1.59±0.05 for 50 mg group and 1.57±0.04 for 100 mg group; incisors: 1.52±0.02 for control group, 1.47±0.01 for 50 mg group and 1.51±0.03 for 100 mg group) (P>0.05). SEM observation showed that the enamel rods of the first molars and incisors in the 50 and 100 mg group varied in size and arranged disorderly. The spaces between the enamel rods were larger than that in the control group and some areas even appeared large pits. HE staining showed that the gaps between ameloblasts in 50 and 100 mg groups were significantly wider than that in the control group. Conclusions: Intake of amoxicillin during the period of enamel development of SD rats might affect enamel mineralization.

Design, synthesis and antitumor evaluation of new 1,8-naphthalimide derivatives targeting nuclear DNA

Four series of new 3-nitro naphthalimides derivatives, 4(4a‒4f), 5(5a‒5i), 6(6a‒6e) and 7 (7a‒7j), were designed and synthesized as antitumor agents. Methyl thiazolyl tetrazolium (MTT) screening assay results revealed that some compounds displayed effective in vitro antiproliferative activity on SMMC-7721, T24, SKOV-3, A549 and MGC-803 cancer cell lines in comparison with 5-fluorouracil (5-FU), mitonafide and amonafide. Nude mouse xenotransplantation model assay results indicated that compounds 6b and 7b exhibited good in vivo antiproliferative activity in MGC-803 xenografts in comparison with amonafide and cisplatin, suggesting that compounds 6b and 7b could be good candidates for antitumor agents. Gel electrophoresis assay indicated that DNA and Topo I were the potential targets of compounds 6b and 7b, and comet assay confirmed that compounds 6b and 7b could induce DNA damage, while the further study showed that the 6b- and 7b-induced DNA damage was accompanied by the upregulation of p-ATM, P-Chk2, Cdc25A and p-H2AX. Cell cycle arrest studies demonstrated that compounds 6b and 7b arrested the cell cycle at the S phase, accompanied by the upregulation of the expression levels of the antioncogene p21 and the down-regulation of the expression levels of cyclin E. Apoptosis assays indicated that compounds 6b and 7b caused the apoptosis of tumor cells along with the upregulation of the expression of Bax, caspase-3, caspase-9 and PARP and the downregulation of Bcl-2. These mechanistic studies suggested that compounds 6b and 7b exerted their antitumor activity by targeting to DNA, thereby inducing DNA damage and Topo I inhibition, and consequently causing S stage arrest and the induction of apoptosis.

Achieving thermodynamic consistency in a class of free-energy multiphase lattice Boltzmann models

The free-energy lattice Boltzmann (LB) model is one of the major multiphase models in the LB community. The present study is focused on a class of free-energy LB models in which the divergence of thermodynamic pressure tensor or its equivalent form expressed by the chemical potential is incorporated into the LB equation via a forcing term. Although this class of free-energy LB models may be thermodynamically consistent at the continuum level, it suffers from thermodynamic inconsistency at the discrete lattice level owing to numerical errors [Guo et al., Phys. Rev. E 83, 036707 (2010)10.1103/PhysRevE.83.036707]. The numerical error term mainly includes two parts: one comes from the discrete gradient operator and the other can be identified in a high-order Chapman-Enskog analysis. In this paper, we propose an improved scheme to eliminate the thermodynamic inconsistency of the aforementioned class of free-energy LB models. The improved scheme is constructed by modifying the equation of state of the standard LB equation, through which the discretization of ∇(ρc_{s}^{2}) is no longer involved in the force calculation and then the numerical errors can be significantly reduced. Numerical simulations are subsequently performed to validate the proposed scheme. The numerical results show that the improved scheme is capable of eliminating the thermodynamic inconsistency and can significantly reduce the spurious currents in comparison with the standard forcing-based free-energy LB model.

NF-κB inhibitory and cytotoxic activities of hexacyclic triterpene acid constituents from Glechoma longituba

BACKGROUND

Non-Small-Cell Lung Cancer (NSCLC) is the most-frequent cause of cancer death, and novel chemotherapeutic drugs for treating NSCLC are urgently needed. 2α, 3α, 23-trihydroxy-13α, 27-cyclours-11-en-28-oic acid (euscaphic acid G) is a new hexacyclic triterpene acid isolated by our group from Glechoma longituba (Nakai) Kupr. However, the underlying mechanisms responsible for the anticancer effects of hexacyclic triterpene acid have not been elucidated.

PURPOSE

In the present work, we evaluated growth inhibitory effect of the new isolated hexacyclic triterpene acid and explored the underlying molecular mechanisms.

METHODS/STUDY DESIGNS

Herbs were extracted and constituents were purified by chromatographic separation, including silica gel, ODS, MCI, Sephadex LH-20 and preparative HPLC. The compound structures were elucidated by the use of UV, NMR and MS spectral data. The anticancer activity of euscaphic acid G was evaluated by MTT assay. Cell cycle, apoptosis, reactive oxygen species and mitochondrial membrane potential were determined by flow cytometry. To display the possible mechanism of euscaphic acid G on NCI-H460 cells, RT-PCR, immunofluorescence and Western blot analysis were carried out.

RESULTS

A new hexacyclic triterpene acid, euscaphic acid G, together with fifteen known triterpenoids, was isolated from the aerial parts of G. longituba. Our results showed that euscaphic acid G exerted strong anti-proliferative activity against NCI-H460 cells in a concentration- and time-dependent manner. Flow cytometry demonstrated euscaphic acid G arrested the cell cycle at G1 phase, induced cellular apoptosis, accompanied by ROS generation and mitochondrial membrane potential reduction. Mechanistic studies revealed that euscaphic acid G treatment inhibited IKKα/β phosphorylation and IκBα phosphorylation, which subsequently caused the blockage of NF-κB p65 phosphorylation and nuclear translocation.

CONCLUSION

In conclusion, these results suggested that euscaphic acid G from G. longituba showed potential anticancer effects against lung cancer cells via inducing cell cycle arrest and apoptosis, at least partly, through NF-κB signaling pathways.

Synthesis and discovery of asiatic acid based 1,2,3-triazole derivatives as antitumor agents blocking NF-κB activation and cell migration

A series of asiatic acid (AA) based 1,2,3-triazole derivatives were designed, synthesized and subjected to a cell-based NF-κB inhibition screening assay. Among the tested compounds, compound 6k displayed impressive NF-κB inhibitory activity with an IC₅₀ value in the low micromolar range. A molecular docking study was performed to reveal key interactions between 6k and NF-κB in which the 1,2,3-triazole moiety and the hydroxyl groups of the AA skeleton were important for improving the inhibitory activity. Subsequently, surface plasmon resonance analysis validated the high affinity between compound 6k and NF-κB protein with an equilibrium dissociation constant (KD) value of 0.36 μM. Further studies showed that compound 6k observably inhibited the NF-κB DNA binding, nuclear translocation and IκBα phosphorylation. Moreover, in vitro antitumor activity screening showed that compound 6k (IC₅₀ = 2.67 ± 0.06 μM) exhibited the best anticancer activity against A549 cells, at least partly, by inhibition of the activity of NF-κB. Additionally, the treatment of A549 cells with compound 6k resulted in apoptosis induction potency and in vitro cell migration inhibition. Thus, we conclude that AA based 1,2,3-triazole derivatives may be potential NF-κB inhibitors with the ability to induce apoptosis and suppress cell migration.

Discovery of antitumor ursolic acid long-chain diamine derivatives as potent inhibitors of NF-κB

A series of inhibitors of NF-κB based on ursolic acid (UA) derivatives containing long-chain diamine moieties were designed and synthesized as well as evaluated the antitumor effects. These compounds exhibited significant inhibitory activity to the NF-κB with IC50 values at micromolar concentrations in A549 lung cancer cell line. Among them, compound 8c exerted potent activity against the test tumor cell lines including multidrug resistant human cancer lines, with the IC50 values ranged from 5.22 to 8.95 μM. Moreover, compound 8c successfully suppressed the migration of A549 cells. Related mechanism study indicated compound 8c caused cell cycle arrest at G1 phase and triggered apoptosis in A549 cells through blockage of NF-κB signalling pathway. Molecular docking study revealed that key interactions between 8c and the active site of NF-κB in which the bulky and strongly electrophilic group of long-chain diamine moieties were important for improving activity.

A pentacyclic triterpene derivative possessing polyhydroxyl ring A suppresses growth of HeLa cells by reactive oxygen species-dependent NF-κB pathway

Pentacyclic triterpene derivatives possessing polyhydroxyl ring A exhibit many important pharmacological activities. (1β, 2α, 3β, 19β, 23)-1,2,3,19,23-pentahydroxyolean-12-en-28-oic acid (5), a new bioactive phytochemical with tetra-hydroxyl ring A isolated from Euphorbia sieboldiana in our laboratory, showed potential inhibition effects against several cancer cells previously. This study was performed to investigate the underlying mechanisms of action for its antitumor activity. The results showed that compound 5 inhibited dose-/time-dependently cell growth with low toxicity to normal cells and induced apoptosis in cervical cancer cells. Also, compound 5 inhibited the growth and proliferation of HeLa cells and resulted in G1 phase arrest. Furthermore, exposure of cells to compound 5 caused inactivation of the TNF-α-TAK1-IKK-NF-κB axis and inhibition of TNF-α-stimulated NF-κB activity, followed by down-regulation of NF-κB target genes involved in cell apoptosis (Bcl-2) and in the cell cycle and growth (Cyclin D, c-Myc). Additionally, compound 5 significantly suppressed the migration of HeLa cells. In addition, exposure of HeLa cells to compound 5 decreased the activity of NF-κB through the generation of reactive oxygen species (ROS). Collectively, these results suggested that compound 5 exerted potent anticancer effects on HeLa cells in vitro through targeting the ROS-dependent NF-κB signaling cascade and this compound may be a promising anticancer agent for cancer treatment.

Design, synthesis and pharmacological evaluation of new 3-(1H-benzimidazol-2-yl)quinolin-2(1H)-one derivatives as potential antitumor agents

A series of new 3-(1H-benzimidazol-2-yl)quinolin-2(1H)-one derivatives (5a₁-5d₆) were designed and synthesized as antitumor agents. In vitro antitumor assay results showed that some compounds exhibited moderate to high inhibitory activity against HepG2, SK-OV-3, NCI-H460 and BEL-7404 tumor cell lines, and most compounds exhibited much lower cytotoxicity against the HL-7702 normal cell line compared to 5-FU and cisplatin. In vivo antitumor assay results demonstrated that 5a₃ exhibited effective inhibition on tumor growth in the NCI-H460 xenograft mouse model and that 5d₃ displayed excellent antiproliferative activity in the BEL-7402 xenograft model. These results suggested that both 5a₃ and 5d₃ could be used as anticancer drug candidates. Mechanistic studies suggested that compounds 5a₃ and 5d₃ exerted their antitumor activity by up-regulation of Bax, intracellular Ca²⁺ release, ROS generation, downregulation of Bcl-2, activation of caspase-9 and caspase-3 and subsequent cleavage of PARP, inhibition of CDK activity and activation of the p53 protein.

Design, synthesis and pharmacological evaluation of novel 2-chloro-3-(1H-benzo[d]imidazol-2-yl)quinoline derivatives as antitumor agents: in vitro and in vivo antitumor activity, cell cycle arrest and apoptotic response

A series of novel 2-chloro-3-(1H-benzo[d]imidazol-2-yl)quinoline derivatives were designed and synthesized as antitumor agents under the combination principle. The antitumor activity and mechanisms were then evaluated.

Anti-proliferative Activities of Two Flavonols with Unsubstituted B-ring from the Leaves of Platanus acerifolia

The anti-proliferative activities against five cancer cell lines of two flavonols (1, 2) with unsubstituted B ring isolated from the ethanol extract of the leaves of Platanus acerifolia were investigated. The results showed that compound 1 possessed a noteworthy anti-proliferative activity against MGC-803 cells with an IC50 value of 17.26±1.04 μM, and compound 2 was less active than 1 with an IC50 value of 20.29±1.37 μM compared with 41.94±1.58 μM for the positive control group. In addition, the results of Hoechst 33258 staining, AO/EB staining and annexinV-FITC assays indicated that 1 caused a significant MGC-803 cellular apoptosis in a dose-dependent manner. The further mechanisms showed that compound 1 induced the production of ROS, decreased the mitochondrial membrane potential, and altered pro- and anti-apoptotic proteins, leading to activation of caspase-9 and caspase-3 in the process of cellular apoptosis. The present investigation indicated that compound 1 could be used as a potential anti-cancer candidate.

4-Methylumbelliferones Analogues as Anticancer Agents: Synthesis and in Cell Pharmacological Studies

BACKGROUND

Cancer is one of the most serious clinical problems worldwide, and considerable efforts have been devoted to discovering therapeutic agents with novel modes of action. Natural and synthetic coumarin derivatives have attracted intense research interest due to their diverse structural features and remarkable array of biological properties.

OBJECTIVE

In the present study, we synthesized a series of 4-MU derivatives containing urea-piperazine and thioureapiperazine moieties and evaluated their antitumor activities to find efficacy antitumor drugs.

METHOD

Cell proliferation, apoptosis, cell cycle, the generation of reactive oxygen species and calcium were measured using MTT assay and flow cytometry, respectively. The expression of apoptosis- and proliferation-related proteins was determined by western blotting. The effect of 4l on apoptosis-related mRNA expression in NCI-H460 cells was detected by RT-PCR.

RESULTS

Most of the target compounds exhibited potential anticancer activities against tested cancer cells but had low cytotoxicity to normal cells. Compound 4l inhibited the growth and proliferation of NCI-H460 cells and resulted in apoptosis. Successive studies conducted with 4l in NCI-H460 cells demonstrated that this compound induced the intracellular reactive oxygen species generation and calcium overload, suppressed nuclear factor-κB (NF-κB) activity and regulated anti- and pro-apoptotic proteins. In addition, compound 4l effectively arrested NCI-H460 cells in G2 phase and altered the cell cycle regulatory proteins especially cyclin B1.

CONCLUSION

Compound 4l exerts significant anticancer effects on NCI-H460 cells in vitro through targeting of mitochondria-dependent apoptotic pathway. These results indicate that the strategy for rational design of 4-MU derivatives may identify potential anticancer agents.

Discovery of dehydroabietic acid sulfonamide based derivatives as selective matrix metalloproteinases inactivators that inhibit cell migration and proliferation

A series of dehydroabietic acid (DHAA) dipeptide derivatives containing the sulfonamide moiety were designed, synthesized and evaluated for inhibition of MMPs as well as the effects of in vitro cell migration. These compounds exhibited relatively good inhibition activity against MMPs with IC₅₀ values in low micromolar range. A docking study of the most active compound 8k revealed key interactions between 8k and MMP-3 in which the sulfonamide moiety and the dipeptide group were important for improving activity. It is noteworthy that further antitumor activity screening revealed that some compounds exhibited better inhibitory activity than the commercial anticancer drug 5-FU. In particular, compound 8k appeared to be the most potent compound against the HepG2 cell line, at least partly, by inhibition of the activity of MMP-3 and apoptosis induction. The treatment of HepG2 cells with compound 8k resulted in inhibition of in vitro cell migration through wound healing assay and G1 phase of cell cycle arrested. In addition, 8k-induced apoptosis was significantly facilitated in HepG2 cells. Thus, we conclude that DHAA dipeptide derivatives containing the sulfonamide moiety may be the potential MMPs inhibitors with the ability to suppress cells migration.

A new aromatic glycoside and its anti-proliferative activities from the leaves of Bergenia purpurascens

Chemical investigation of the ethanolic extracts of the dried leaves of Bergenia purpurascens led to the isolation and identification of a new aromatic glycoside, 1-O-β-D-glucopyranosyl-2-methoxy-3-hydroxyl-phenylethene (1), along with other 19 known compounds (2-20). The structure of compound 1 was determined by a detailed analysis using various analytical techniques, including 1D and 2D NMR. In vitro anti-proliferative activities of compound 1 on five human cancer cell lines were evaluated. The results showed that compound 1 possessed the most potent effects with the IC₅₀ values of 14.36 ± 1.04 μM against T24 cells. The further bioactivity analysis showed that compound 1 induced apoptosis of T24 cells, and altered anti- and pro-apoptotic proteins, leading to mitochondrial dysfunction and activation of caspase-3 for causing cell apoptosis. The present investigation illustrated compound 1 might be used as a potential antitumour chemotherapy candidate.

Selagintamarlin A: A Selaginellin Analogue Possessing a 1H-2-Benzopyran Core from Selaginella tamariscina

Selagintamarlin A (1), a novel selaginellin analogue featuring the unique motif of 1H-2-benzopyran, a new selaginpulvilin E (2), together with eight known analogues were isolated from Selaginella tamariscina. Their structures were elucidated by extensive spectroscopic analyses. A plausible biosynthetic pathway of 1 was also postulated. Compound 1 showed remarkable inhibitory activity against phosphodiesterase-4 (PDE4D2), with an IC₅₀ value of 40 nM, which is 20-fold higher than that of the positive control (rolipram). Furthermore, compound 1 significantly inhibited tubulin polymerization.

Side chain-functionalized aniline-derived ursolic acid derivatives as multidrug resistance reversers that block the nuclear factor-kappa B (NF-κB) pathway and cell proliferation

A series of inhibitors of NF-κB based on ursolic acid (UA) derivatives containing functionalized aniline or amide side chains were synthesized and evaluated for inhibition of NF-κB as well as their antitumor effects. These compounds exhibited significant inhibition activity toward NF-κB with IC₅₀ values at micromolar concentrations in the NCI-H460 lung adenocarcinoma cell line. A docking study of the most active compound 5Y8 revealed key interactions between 5Y8 and the active site of NF-κB in which the functionalized amide moiety at the C-28 position and an ester group at the C-3 position were important for improving the activity. In particular, compound 5Y8 appeared to be the most potent compound against the NCI-H460 cell line, and displayed similar efficiency in drug-sensitive versus drug-resistant cancer cell lines, at least partly, by blocking the NF-κB signaling pathway and inducing apoptosis. Mechanistically, compound 5Y8 might trigger the apoptotic signaling pathway. Thus, the rational design of UA derivatives with functionalized aniline or amide side chains offers significant potential for the discovery of a new class of NF-κB inhibitors with the ability to induce apoptosis and reverse multidrug resistance in the NCI-H460 lung adenocarcinoma cell line.

Three new C-27-carboxylated-lupane-triterpenoid derivatives from Potentilla discolor Bunge and their in vitro antitumor activities

Three new lupane-triterpenoids (1-3) along with six known compounds (4-9) were isolated from the ethanolic extract of whole plant of Potentilla discolor Bunge. The structures of Compounds 1-3 were established by extensive 1D and 2D NMR together with other spectrum analysis, indicating that their C-27 positions were highly oxygenated, which were rarely found in nature. Their in vitro anti-proliferative activities against HepG-2, MCF-7 and T-84 cell lines were evaluated by Cell Counting Kit-8 (CCK-8) assay, and the results showed different activities for three cell lines with IC50 values ranging from 17.84 to 40.64 μM. In addition, the results from Hoechst 33258 and AO/EB staining as well as annexinV-FITC assays exhibited Compound 1 caused a markedly increased HepG-2 cellular apoptosis in a dose-dependent manner. The further mechanisms of Compound 1-induced cellular apoptosis were confirmed that 1 induced the production of ROS and the alteration of pro- and anti-apoptotic proteins, which led to the dysfunction of mitochondria and activation of caspase-9 and caspase-3 and finally caused cellular apoptosis. These results would be useful in search for new potential antitumor agents and for developing semisynthetic lupane-triterpenoid derivatives with high antitumor activity.

Cytotoxic triterpenoid saponins from Lysimachia foenum-graecum

Eleven oleanane-type triterpenoid saponins, foegraecumosides A-K, and eight known ones, were isolated from the aerial parts of Lysimachia foenum-graecum. Their structures were elucidated by spectroscopic data analyses and chemical methods. All isolated saponins were evaluated for their cytotoxicity against four human cancer cell lines (NCI-H460, MGC-803, HepG2, and T24). Seven saponins containing the aglycone cyclamiretin A exhibited moderate cytotoxicity against all tested human cancer cell lines, with IC₅₀ values of 9.3-24.5 μM. Simultaneously, the cytotoxic activities of foegraecumosides A and B, lysichriside A, ardisiacrispins A and B, cyclaminorin, and 3-O-α-L-rhamnopyranosyl-(1 → 2)-β-d-glucopyranosyl-(1 → 4)-α-l-arabinopyranosyl-cyclamiretin A were tested on drug-resistant lung cancer cell lines (A549 and A549/CDDP, respectively). Ardisiacrispin B displayed moderate cytotoxicity against A549/CDDP, with an IC₅₀ value of 8.7 μM and a resistant factor (RF) of 0.9.

Gapless Spin-Liquid Ground State in the S=1/2 Kagome Antiferromagnet

The defining problem in frustrated quantum magnetism, the ground state of the nearest-neighbor S=1/2 antiferromagnetic Heisenberg model on the kagome lattice, has defied all theoretical and numerical methods employed to date. We apply the formalism of tensor-network states, specifically the method of projected entangled simplex states, which combines infinite system size with a correct accounting for multipartite entanglement. By studying the ground-state energy, the finite magnetic order appearing at finite tensor bond dimensions, and the effects of a next-nearest-neighbor coupling, we demonstrate that the ground state is a gapless spin liquid. We discuss the comparison with other numerical studies and the physical interpretation of this result.

Design, synthesis and pharmacological evaluation of new 2-oxo-quinoline derivatives containing α-aminophosphonates as potential antitumor agents

A series of novel 2-oxo-quinoline derivatives containing α-aminophosphonates were designed and synthesized as antitumor agents. MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay results demonstrated that some compounds exhibited moderate to high inhibitory activity against HepG2, SK-OV-3 and NCI-H460 tumor cell lines, and most compounds showed much lower cytotoxicity against HL-7702 normal cells than 5-FU and cisplatin. The action mechanism of representative compound 5b was investigated by fluorescence staining assay, flow cytometric analysis and western blot (WB) assay, which indicated that this compound induced apoptosis and G₂/M phase arrest accompanied by an increase in the production of intracellular Ca²⁺ and reactive oxygen species (ROS) and affecting associated enzymes and genes.

Synthesis and biological evaluation of terminal functionalized thiourea-containing dipeptides as antitumor agents

Terminal functionalized dipeptide derivatives containing the thiourea moiety were synthesized and evaluated for antitumor activity. Representative compoundI-11induced apoptosis by the ROS-dependent endoplasmic reticulum pathway in NCI-H460 cells.

Cytisine-type alkaloids and flavonoids from the rhizomes of Sophora tonkinensis

A new cytisine-type alkaloid, (-)-N-hexanoylcytisine (1), and a new isoflavan, (3S, 4R)-4-hydroxy-7,4'-dimethoxyisoflavan 3'-O-β-d-glucopyranoside (2), along with 10 known compounds, were isolated from the rhizomes of Sophora tonkinensis. Their structures were determined by spectroscopic methods, chemical evidence, and ECD data analysis. All of the isolates were evaluated for their cytotoxic activities against four human tumor cell lines.

Synthesis, antiproliferative and apoptosis-inducing effects of novel asiatic acid derivatives containing α-aminophosphonates

Novel asiatic acid derivatives containing α-aminophosphonates was designed and synthesized as antitumor agents. Compound 3d blocked the T24 cell cycle at G₁/S phase by the p53-dependent pathway and induced apoptosis through mitochondrial pathway.

Design, synthesis and in vitro evaluation of novel ursolic acid derivatives as potential anticancer agents

A series of novel ursolic acid (UA) derivatives modified at the C-3 and the C-28 positions were designed and synthesized in an attempt to develop potential antitumor agents. The in vitro cytotoxicity were evaluated against five cancer cell lines (MGC-803, HCT-116, T24, HepG2 and A549 cell lines) and a normal cell (HL-7702) by MTT assay. The screening results indicated that some of these target compounds displayed moderate to high levels of antiproliferative activities compared with ursolic acid and 5-fluorouracil (5-FU), and exhibited much lower cytotoxicity than 5-FU, indicating that the targeted compounds had selective and significant effect on the cell lines. The induction of apoptosis and affects on the cell cycle distribution of compound 6r were investigated by acridine orange/ethidium bromide staining, Hoechst 33258 staining, JC-1 mitochondrial membrane potential staining and flow cytometry, which revealed that the antitumor activity of 6r was possibly achieved through the induction of cell apoptosis by G1 cell-cycle arrest. Western blot and qRT-PCR (quantitative real-time PCR) experiments demonstrated that compound 6r may induce apoptosis through both of intrinsic and extrinsic apoptosis pathway.

Synthesis and pharmacological evaluation of novel bisindole derivatives bearing oximes moiety: identification of novel proapoptotic agents

In an effort to develop potent anti-cancer chemopreventive agents, a novel series of bisindole derivatives bearing oxime moiety were synthesized. Structures of all compounds were characterized by NMR and HRMS. Anti-proliferative activities for all of these compounds were investigated by the method of MTT assay on 7 human cancer lines and the normal cell lines (HUVEC). Most of them showed a noteworthy anti-cancer activity in vitro, the half maximal inhibitory concentration (IC50) value is 4.31 μM of 4e against T24. The results from Hoechst 33258 and acridine orange/propidium iodide staining as well as annexinV-FITC assays provided evidence for an apoptotic cell death. The further mechanisms of compound 4e-induced apoptosis in T24 cells demonstrated that compound 4e induced the productions of ROS, and altered anti- and pro-apoptotic proteins, leading to mitochondrial dysfunction and activations of caspase-9 and caspase-3 for causing cell apoptosis. Moreover, the cell cycle analysis and western-blot analysis indicated that compound 4e effectively arrested T24 cells in G1 stage and possibly has an effect on cell cycle regulatory proteins particularly cyclin D1.

Interaction of scanning tunneling microscopy tip with mesoscopic islands at the atomic-scale

Performing atomic-scale simulations, we study the interaction of the scanning tunneling microscopy (STM) tip with mesoscopic islands at zero bias voltage. Our calculations reveal tip-induced shape transitions in Co islands on Cu(100) as the tip approaches the surface. The structure of the islands and of the tip are found to depend strongly on the tip-substrate distance. A significant influence of the tip on atomic diffusion on the top and at the edges of the islands is demonstrated. The size-dependent strain relief in the islands caused by the tip and by the substrate is found to play a key role in atomistic processes on islands. Our results show that, for certain tip-surface separations, the hopping diffusion of Co adatoms on the top of Co islands and the upward mass transport at the edge of the islands can be strongly enhanced. Our findings point out the possibility of manipulating atomic motion on mesoscopic islands using the STM tip.