Apoptotic pathway induced by diallyl trisulfide in pancreatic cancer cells

AIM:To investigate the effects of diallyl trisulfide(DATS),a garlic-derived organosulfur compound,in pancreatic cancer cells.METHODS:Human pancreatic cancer cells with wildtype p53 gene(Capan-2)and normal pancreatic epithelial cells(H6C7)were cultured in RPMI1640.DATS was prepared at a concentration of 100μmol/L.Cell viability was determined via the methyl thiazolyl tetrazolium assay.Apoptotic cells were detected by TUNEL assay.Cell cycle analysis was performed using flow cytometry.Protein expression was determined by Western blot.Bax and Bcl-2 expression was detected by immunofluorescence.Apoptosis genes and cell cycle were assessed by quantitative real-time polymerase chain reaction.RESULTS:DATS suppressed the viability of cultured human pancreatic cancer cells(Capan-2)by increasing the proportion of cells in the G2/M phase and induced apoptotic cell death.Western blot analysis indicated that DATS enhanced the expression of Fas,p21,p53and cyclin B1,but downregulated the expression of Akt,cyclin D1,MDM2 and Bcl-2.DATS induced cell cycle inhibition which was correlated with elevated levels of cyclin B1 and p21,and reduced levels of cyclin D1 in Capan-2 cells and H6C7 cells.DATS-induced apoptosis was markedly elevated in Capan-2 cells compared with H6C7 cells,and this was correlated with elevated levels of cyclin B1 and p53,and reduced levels of Bcl-2.DATS-induced apoptosis was correlated with downregulation of Bcl-2,Akt and cyclin D1 protein levels,and up-regulation of Bax,Fas,p53 and cyclin B protein levels in Capan-2 cells.CONCLUSION:DATS induces apoptosis of pancreatic cancer cells(Capan-2)and non-tumorigenic pancreatic ductal epithelial cells(H6C7).

Diallyl disulfide and diallyl trisulfide in garlic as novel therapeutic agents to overcome drug resistance in breast cancer

Breast cancer is one of the leading causes of cancer-related deaths in women worldwide.It is a cancer that originates from the mammary ducts and involves mutations in multiple genes.Recently,the treatment of breast cancer has become increasingly challenging owing to the increase in tumor heterogeneity and aggressiveness,which gives rise to therapeutic resistance.Epidemiological,populationbased,and hospital-based case-control studies have demonstrated an association between high intake of certain Allium vegetables and a reduced risk in the development of breast cancer.Diallyl disulfide(DADS)and diallyl trisulfide(DATS)are the main allyl sulfur compounds present in garlic,and are known to exhibit anticancer activity as they interfere with breast cancer cell proliferation,tumor metastasis,and angiogenesis.The present review highlights multidrug resistance mechanisms and their signaling pathways in breast cancer.This review discusses the potential anticancer activities of DADS and DATS,with emphasis on drug resistance in triple-negative breast cancer(TNBC).Understanding the anticancer activities of DADS and DATS provides insights into their potential in targeting drug resistance mechanisms of TNBC,especially in clinical studies.

Triple-phase interfaces of graphene-like carbon clusters on antimony trisulfide nanowires enable high-loading and long-lasting liquid Li_(2)S_(6)-based lithium-sulfur batteries

High performance of lithium-sulfur batteries have been dragged down by their shuttling behavior which is complicated multiphase transition-based 16-electron redox reactions of the S8/Li2 S.In this article,the triple-phase interfaces of graphene-like carbon clusters on antimony trisulfide(C-Sb_(2)S_(3))nanowires are tailored to design a multifunctional polysulfide host which can inhibit migration of polysulfides and accelerate conversion kinetics of redox electrochemical reactions.Benefiting from the triple-interface design of polysulfides/Sb_(2)S_(3)/carbon clusters,the C-Sb_(2)S_(3) electrode not only anchors polysulfide migration by the synergistic effect of Sb,S,and C atoms as interfacial active sites,but also the graphene-like carbon clusters shorten the diffusion paths to further favor redox electron/ion transport through the liquid(electrolyte/polysulfide)and solid(Li2 S/S8,carbon clusters,and Sb_(2)S_(3))-based triple-phases.Therefore,these Li_(2)S_(6)-based C-Sb_(2)S_(3) cells possess high sulfur loading,excellent cycling stability,impressive specific capacity,and great rate capability.This work of interfacial engineering reveals insight for powering reaction kinetics in the complicated multistep catalysis reaction with multiphase evolution-based chargetransfer/non-transfer processes.

Protective Effect of Diallyl Trisulfide on Liver in Rats with Sepsis and the Mechanism

The protective effects of diallyl trisulfide on liver were examined in rats with sepsis. Sepsis was reproduced in rats by cecum ligation and puncture (CLP). Fifty-six male Wistar rats were randomly divided into sham-operated group (group S, n=8), sepsis model group (group C, n=24), diallyl trisulfide (DATS)-treated group (group D, n=24). Animals in groups C and D were further divided into three subgroups according to different observation time points, with 8 rats in each sub-group.Rats in group D and C were intravenously injected with normal saline or DATS respectively at a dose of 20 mg/kg after the establishment of sepsis model. Eight rats in groups C and D were sacrificed at 3, 6 and 24 h post-CLP and their livers were harvested for detection of interleukin (IL)-1 receptor associated kinase-4 (IRAK-4), nuclear factor-κB (NF-κB), c-fos, c-jun, malondialdehydethhe (MDA) and superoxide dismutase (SOD), tumor necrosis factor alpha (TNF-α) and for pathological examination. The results showed that the levels of serum IRAK-4, NF-κB and TNF-α in hepatic tissues were higher in group C than group S (control group) (P<0.05). After DATS treatment, the levels of IRAK-4 and NF-κB in the hepatic tissues and serum TNF-α in group D were lower than those in group C (P<0.05). The levels of c-fos and c-jun and MDA in the hepatic tissues were higher in group C than in group S (P<0.05). After DATS treatment, the levels of c-fos and c-jun and MDA in the hepatic tissues were significantly lower in group D than in group C (P<0.05). When compared with group S group, concentration of SOD in the hepatic tissues in group C was significantly lower (P<0.05). After DATS treatment, the concentration of SOD in the hepatic tissues was higher in group D than in group C (P<0.05). These findings suggested that treatment with DATS could ameliorate sepsis-induced liver injury in rats. The protective effect might be related to its ability to inhibit the signal pathway of IRAK-4 and NF-κB, thereby decreasing the production of oxygen free radicals and down-regulating the expression of c-fos and c-jun.

Effect of Diallyl Trisulfide on the Activation of T Cell and Macrophage－mediated Cytotoxicity

At high concentration (50 μg/ml), diallyl trisulfide (DATS) had an inhibitory effect on T cell activation (compared with control group, P<0.05). But at appropriate concentrations(3.125-12. 5 μg/ml). DATS augmented the activation of T lymphocytes by Con A (compared with control group, P<0. 01). The augmentation of T cell activation by DATS was related to its inhibitory effect on the production of nitric oxide (NO) by macrophages.In a wide range of concentrations (1-100 μg/ml) , DATS can inhibit the production of NO by macrophas,es (P<0.05,P<0.01). In addition, DATS can antagonize the inhibition of tumor-derived immunosuppressive factors produced by S180 cells and Ehrlich ascitic cancer cells on the activation of T cells, and reduce the inhibitory rate significantly (P<0.01). DATS, despite its inhibition of the production of NO by macrophages, can significantly enhance the production of hydrogen peroxide (H2O2 by macrophages.When macrophages were pretreated with DATS for 24 h, the cytotoxicity % of macrophages to three tumor cell lines was significantly higher than that in corresponding control group (P<0.05,P<0.01). In the presence of both DATS and LPS, the cytotoxicity of macrophages was further enhanced so that the cytotoxicity % of macrophages to tumor cells was significantly higher than either that in the presence of DAIS alone or that in the presence of LPS alone(P<0.05, P<0.01). These results indicate that DATS can augment the activation of T cells and enhance the anti-tumor function of macrophage, suggesting that DATS may be potentially useful in tumor therapy.

The production and cytotoxicity of the reactive oxygen species (ROS) induced by diallyl trisulfide (DATS) in human myeloid leukemia HL-60 cells

Objective To explore the production and cytotoxicity of the reactive oxygen species(ROS)induced by diallyl trisulfid(DATS)in HL-60 cells.Methods HL-60 cells were either treated with various doses of DATS alone,or DATS combination with Apocynin,a specific NADPH oxidase inhibitor,or with antioxidant N-acetyl-L-cysteine(NAC)for 0,1,3,6,12 and 24 hours,respectively.The intracellular ROS level was measured by flow cytometry.The activity of NADPH oxidase was evaluated by NBT reduction experiment.The content of both malondialdehyde(MDA)and the protein carbonyl was analyzed by spectrophotometer.Results The results from flow cytometry indicated that DATS significantly increased the intracellular ROS level in HL-60 cells(P<0.05),which is a dose-and time-dependent.The fluorescence intensities of ROS reached at maximuam when HL-60 cells were incubated with 150 μmol·L-1 DATS for 3 hours.The NBT reduction experiment showed that DATS activated NADPH oxidase which had highest activity when cell were exposed to 150 μmol·L-1 DATS for 3 hours.Results DATS induced MDA and protein carbonyl production in HL-60 cells.Furrthermore,both MDA and protein carbonyl in the cells exposed to 150 μmol·L-1 DATS for 3 hours reached the highest level.Apocynin and NAC could attenuate the production of MDA and protein carbonyl,which suggested that ROS induced by DATS was involved in the toxicity to cells.Conclusions DATS induce ROS production through activating NADPH oxidase in HL-60 cells.ROS induced by DATS increase the oxidation of the membrane lipid and the protein of HL-60 cell.

Diallyl trisulfide activates NADPH oxidase by inducing the expression of NADPH oxidase subunits and translocation of both Rac2 and p67phox subunit in HL-60 cells

Objective To explore the effect and mechanism of diallyl trisulfide on the activity of NADPH oxidase in Hl-60 cells.Methods HL-60 cells were treated with DATS at a indicated concentration for 0,1,3,6,12 hours,respectively.The activity of NADPH oxidase was measured by the reduction of the yellow dye nitroblue tetrazolium(NBT).The mRNA expression of NADPH oxidase subunits,including gp91phox,p47 phox,p22 phox,Rac2 and Rac1,was detected by RT-PCR.The protein expression of p67 phox,gp91 phox and Rac2 was analyzed by Western blot.The cell membrane fractions were prepared according to the instruction of Mem-PER kit from Pierce Corp.Results The results showed that reduction ability of HL-60 cells for NBT markedly increased in a concentration-dependent manner following DATS incubation for 3 and 6 hours(P<0.05).HL-60 cells treated by DATS at a concentration of 150 μM for 3 hours have a maximal reduction effect for NBT.The results from RT-PCR indicated that mRNA expression of NADPH oxidase subunits,including p47phox,gp91 phox,p22 phox,Rac2 and Rac1,significantly increased in a concentration-dependent manner in HL-60 cells treated by DATS.The results from western blot showed that HL-60 cells following DATS incubation have a higher level expression of Rac2 and gp91phox,compared with untreated-HL-60 cells.Our results also indicated that a maximal expression level of p47phox,gp91 phox,p22 phox,Rac2 and Rac1in HL-60 cells is present at 3 hours following DATS incubation.We found that levels of both Rac2 and p67phox was reduced in the cytosolic fraction and meanwhile increased in the membrane fraction following HL-60 exposed to DATS,Which is dependent on the concentration and time of DATS treatment.Furthermore,the level of both Rac2 and p67phox located to the plasma membrane translocation was maximized following 150 μM of DATS incubation for 3 hours.Conclusions DATS induce the activation of NADPH oxidase by both up-regulating the expression of NADPH oxidase subunit and translocating the cytosolic Rac2 and p67 phox subunit to the plasma membrane in HL-60 cells.

Effect of Diallyl Trisulfide on Induction of UDS by Mutagenic Drugs in Primary Rat Hepatocytes

Mosl of anticancer drugs are mutagenic. A possible exeeption is diallyl .trisulfide(DAT ), a component of garlic. It is an antimutagenic anticunccr chemical although it ismainly uscd as antibiotic. Its modifying effeci on induction of UDS by mutagenicmitomycin C (MMC), cyclophosphamide (CP) and cis-diamine dichloroplatin (DDP) was invcstigiltcd with the UDS assay in the primary cultures of Wistar rat hepatocytes (hpc)using the autoradiographic technique. Resultsshowed that 1.0-4.0 nmol/ml of DAT didnot inducc UDS and that MMC, CP and DDP resulted in a significant induction ofdosc-dependent UDS. DAT enhanced induction of UDS by these drugs. A dose-effectrclationship was observed betwecn dose of DAT and enhancement of induction of UDS.Howcvcr, thc mcchanism of the enhancement is not clear.

Graphene-supported bimetal phosphorus trisulfides as novel 0D–2D nanohybrid for high rate Li-ion storage

Herein, we report on the synthesis and Li-ion storage properties of the 0D–2D nanohybrid consisted of bimetal phosphorus trisulfides nanoneedles（Co_（0.5）Ni_（0.5）PS_3） and graphene nanosheets（denoted as Co_（0.5）Ni_（0.5）PS_3@G）. By choosing the Co_（0.5）Ni_（0.5）（OH）_2 nanoneedles as precursor, the Co_（0.5）Ni_（0.5）PS_3 derived by a simple solid-state transformation（SST） process was successfully attached onto the graphene surface.The as-prepared nanohybrids showed a superior cycling stability and rate performance for Li-ion storage.After cycling at a current density of 0.5 A g^（-1） for 500 cycles, the capacity are 456 mAh g^（-1）. Particularly,the capacity can reach 302 mAh g^（-1） at a current density of 10 A g^（-1）, which is 66.2% of the capacity at0.5 A g^（-1）. Even cycling at a current density of 50 A g^（-1）, the nanocomposite can still kept a capacity of 153 mAh g^（-1） with a capacity retention of 33.6%.

Experimental and theoretical investigation on degradation of dimethyl trisulfide by ultraviolet/peroxymonosulfate: Reaction mechanism and influencing factors

With a large amount of domestic sewage and industrial wastewater discharged into the water bodies,sulfur-containing organicmatter inwastewater produced volatile organic sulfide,such as dimethyl trisulfide(DMTS)throughmicroorganisms,caused the potential danger of drinking water safety and human health.At present,there is still a lack of technology on the removal of DMTS.In this study,the ultraviolet/peroxymonosulfate(UV/PMS)advanced oxidation processes was used to explore the degradation of DMTS.More than 90%of DMTS(30μg/L)was removed under the conditions of the concentration ratio of DMTS to PMS was 3:40,the temperature(T)was 25±2℃,and 10 min of irradiation by a 200 W mercury lamp(365 nm).The kinetics rate constant k of DMTS reacting with hydroxyl radical(HO·)was determined to be 0.2477 min^(−1).Mn^(2+),Cu^(2+)and NO_(3)^(-)promoted the degradation of DMTS,whereas humic acid and Cl-in high concentrations inhibited the degradation process.Gas chromatography-mass spectrometry was used to analyze the degradation products and the degradation intermediates were dimethyl disulfide and methanethiol.Density functional theory was used to predict the possible degradation mechanism according to the frontier orbital theory and the bond breaking mechanism of organic compounds.The results showed that the S–S,C–S and C–H bonds in DMTS molecular structure were prone to fracture in the presence of free radicals,resulting in the formation of alkyl radicals and sulfur-containing radicals,which randomly combined to generate a variety of degradation products.

Demonstration of an As₂S₃Grating Coupler on Thin Film LiNbO₃

We present both design and experimental results for an As2S3 grating coupler on a thin film LiNbO3 substrate. A basic grating coupler structure is designed with coupling efficiency of 53% to a single mode fiber. A maximum simulated coupling efficiency of 78.8% is achieved, assuming a polymer bonding process. The basic structure was fabricated, and the coupling efficiency was measured to be at least 23.4% at 1540 nm. Some of the loss may be attributable to non-grating sources, such as waveguide tapers and testing fiber tails. A grating cavity was then measured using the grating couplers. The cavity waveguide propagation loss was 2.0 dB/cm. For a 400 nm thick As2S3 on 500 nm thin film LiNbO3 on insulator, the confinement factor in the LiNbO3 crystal is 82.3% when the As2S3 waveguide width is 400 nm, showing that As2S3-on-thin film LiNbO3 is an excellent candidate for thin film electro-optic applications.

Strain-induced band gap engineering in layered TiS3

By combining ab initio calculations and experiments, we demonstrate how the band gap of the transition metal trichalcogenide TiS3 can be modified by inducing tensile or compressive strain. In addition, using our calculations, we predicted that the material would exhibit a transition from a direct to an indirect band gap upon application of a compressive strain in the direction of easy electrical transport. The ability to control the band gap and its nature could have a significant impact on the use of TiS3 for optical applications. We go on to verify our prediction via optical absorption experiments that demonstrate a band gap increase of up to 9% （from 0.99 to 1.08 eV） upon application of tensile stress along the easy transport direction.