Antiproliferative triterpenoid saponins from the stem of Psychotria sp.

Six new triterpenoid saponins, psychotrianosides A-F (1-6), and two known triterpenoid saponins, psychotrianoside G (7) and ardisianoside D (8), were isolated from Psychotria sp. Their structures were determined mainly by spectroscopic methods. The cytotoxic activities of 1-8 against five human cancer cell lines (MDA-MB-231, MCF-7, MCF-7/ADM, HepG2, and HepG2/ADM) are reported for the first time. Psychotrianoside C (3) showed the most potent antiproliferative activity among these saponins, and the IC50 value of 3 against MDA-MB-231 was 2.391 ± 0.161 µM. Compound 3 was also found to induce apoptosis.

2-(3,5-Dibromo-4-hydroxyphenyl)imidazo[4,5-f][1,10]phenanthrolinoruthenium(II) complexes: synthesis, characterization, cytotoxicity, apoptosis, DNA-binding and antioxidant activity.

A new ligand DBHIP and its two ruthenium(II) complexes [Ru(dmb)(2)(DBHIP)](ClO(4))(2) (1) and [Ru(dmp)(2)(DBHIP)](ClO(4))(2) (2) have been synthesized and characterized. The cytotoxicity of DBHIP and complexes 1 and 2 has been assessed by MTT assay. The apoptosis studies were carried out with acridine orange/ethidium bromide (AO/EB) staining methods. The binding behaviors of these complexes to calf thymus DNA (CT-DNA) were studied by absorption titration, viscosity measurements, thermal denaturation and photoactivated cleavage. The DNA-binding constants of complexes 1 and 2 were determined to be 8.64 +/- 0.16 x 10(4) (s = 1.34) and 2.79 +/- 0.21 x 10(4) (s = 2.17) M(-1). The results suggest that these complexes interact with DNA through intercalative mode. The studies on the mechanism of photocleavage demonstrate that superoxide anion radical (O(2)(*-)) and singlet oxygen ((1)O(2)) may play an important role in the DNA cleavage. The experiments on antioxidant activity show that these compounds also exhibit good antioxidant activity against hydroxyl radical (OH*).

Synthesis, structure, DNA-binding properties, and cytotoxicity of ruthenium(II) polypyridyl complexes.

Many ruthenium(II) complexes show high antitumor activities, and the in vitro antitumor activities are usually related to DNA binding. We designed and synthesized two Ru(II) polypyridyl complexes, [Ru(dmp)2(fpp)]2+ (dmp=2,9-dimethyl-1,10-phenanthroline; fpp=2-[3,4-(difluoromethylenedioxy)phenyl]imidazo[4,5-f] [1,10]phenanthroline and [Ru(phen)(2)(fpp)]2+ (phen=1,10-phenanthroline). The DNA-binding properties of these complexes have been investigated by spectroscopic titration, DNA melting experiments, viscosity measurements, and photoactivated cleavage. The mechanism studies of photocleavage revealed that singlet oxygen (1O2) and superoxide anion radical (O2(.-)) may play an important role in the photocleavage. The cytotoxicity of complexes 1 and 2 have been evaluated by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide) method; complex 2 shows slightly higher anticancer potency than 1 does against all the cell lines screened.

DNA-binding and photocleavage properties of cationic porphyrin-anthraquinone hybrids with different lengths of links.

Four cationic porphyrin-anthraquinone (Por-AQ) hybrids differing in lengths of flexible alkyl linkage, 5-[4-(1-N-anthraquinonon-yl)-L-oxophenyl]-10,15,20-tris(N-methylpyridinium-4-yl)porphyrin triiodide, (L = acetyl, pentanoyl, octanoyl, undecanoyl, designed as [AQATMPyP]I3, [AQPTMPyP]I3, [AQOTMPyP]I3 and [AQUTMPyP]I3, respectively, see Fig. 1), were synthesized and their interactions with DNA were investigated. The results of spectroscopic, denaturation and viscosity measurements suggest that [AQATMPyP]I3 binds to DNA through non-intercalative mode while the other three hybrids with longer links bind via bis-intercalative mode. Ethidium bromide (EB) competition experiment was carried out to determine the binding constants (Kb) of these compounds for CT DNA, and [AQPTMPyP]I3 shows the largest Kb among these hybrids. The photocleavage mechanism and wavelength-dependent cleaving abilities of these hybrids to pBR322 plasmid DNA were also comparably investigated.

Platycodin D induced apoptosis and autophagy in PC-12 cells through mitochondrial dysfunction pathway.

In this article, the in vitro cytotoxicity of platycodin D was evaluated in human PC-12, SGC-7901, BEL-7402, HeLa and A549 cancer cell lines. PC-12 cells were sensitive to platycodin D treatment, with an IC50 value of 13.5±1.2µM. Morphological and comet assays showed that platycodin D effectively induced apoptosis in PC-12 cells. Platycodin D increased the levels of reactive oxygen species (ROS) and induced a decrease in mitochondrial membrane potential. Platycodin D induced cell cycle arrest at the G0/G1 phase in the PC-12 cell line. Platycodin D can induce autophagy. In addition, platycodin D can down-regulate the expression of Bcl-2 and Bcl-x, and up-regulate the levels of Bid protein in the PC-12 cells. The results demonstrated that platycodin D induced PC-12 cell apoptosis through a ROS-mediated mitochondrial dysfunction pathway.

Protein binding and anticancer activity studies of ruthenium(II) polypyridyl complexes toward BEL-7402 cells.

Four new ruthenium(II) polypyridyl complexes [Ru(dmb)2(dqtbt)](ClO4)2 (1) (dqtbt=12-(2,3-diphenyl-quinoxalin-6-yl)-4,5,10,13-tetraazabenzo[b]triphenylene, dmb=4,4'-dimethyl-2,2'-bipyridine), [Ru(bpy)2(dqtbt)](ClO4)2 (2) (bpy=2,2'-bipyridine), [Ru(phen)2(dqtbt)](ClO4)2 (3) (phen=1,10-phenanthroline) and [Ru(dmp)2(dqtbt)](ClO4)2 (4) (dmp=2,9-dimethyl-1,10-phenanthroline) were synthesized and characterized. The cytotoxicity in vitro of the complexes was evaluated against human BEL-7402, A549, HeLa, HepG-2 and MG-63 cancer cell lines. These complexes are sensitive to BEL-7402 cells, the IC50 values are 4.9±0.5, 4.6±0.4, 7.7±1.8 and 1.9±0.3µM toward BEL-7402 cells. The complexes can increase the levels of reactive oxygen species and induce the decrease of mitochondrial membrane potential. Morphological and comet assay studies show that the complexes can effectively induce apoptosis in BEL-7402 cells. Complexes 1-4 inhibit the cell growth at G0/G1 phase in BEL-7402 cell line. The complexes can downregulate the expression of Bcl-2 and Bcl-x proteins and upregulate the levels of Bid protein in BEL-7402 cells. The results show that the complexes induce BEL-7402 cell apoptosis through a ROS-mediated mitochondrial dysfunction pathway. In addition, the complexes show strong protein-binding affinities.

The induction of apoptosis in HepG-2 cells by ruthenium(II) complexes through an intrinsic ROS-mediated mitochondrial dysfunction pathway.

Four new ruthenium(II) polypyridyl complexes [Ru(N-N)2(dhbn)](ClO4)2 (N-N = dmb: 4,4'-dimethyl-2,2'-bipyridine 1; bpy = 2,2'-bipyridine 2; phen = 1,10-phenanthroline 3; dmp = 2,9-dimethyl-1,10-phenanthroline 4) were synthesized and characterized. The cytotoxicity in vitro of the ligand and complexes toward HepG-2, HeLa, MG-63 and A549 were assayed by MTT method. The IC50 values of the complexes against the above cells range from 17.7 ± 1.1 to 45.1 ± 2.8 µM. The cytotoxic activity of the complexes against HepG-2 cells follows the order of 4 > 2 > 3 > 1. Ligand shows no cytotoxic activity against the selected cell lines. Cellular uptake, apoptosis, comet assay, reactive oxygen species, mitochondrial membrane potential, cell cycle arrest, and the expression of proteins involved in apoptosis pathway induced by the complexes were investigated. The results indicate that complexes 1-4 induce apoptosis in HepG-2 cells through an intrinsic ROS-mediated mitochondrial dysfunction pathway.

DNA interaction, antioxidant activity, and bioactivity studies of two ruthenium(II) complexes.

Two new ruthenium(II) polypyridyl complexes [Ru(dmb)2(dcdppz)](ClO4)2 (1) and [Ru(bpy)2(dcdppz)](ClO4)2 (2) were prepared and characterized. The crystal structure of the complex 2 was solved by single crystal X-ray diffraction. The complex crystallizes in the monoclinic system, space group P21/n with a=12.9622(14)Å, b=17.1619(19)Å, c=22.7210(3)Å, ß=100.930(2)(°), R=0.0536, Rω=0.1111. The DNA-binding constants for complexes 1 and 2 were determined to be 1.92×10(5) (s=1.72) and 2.24×10(5) (s=1.86)M(-1), respectively. The DNA-binding behaviors showed that complexes 1 and 2 interact with DNA by intercalative mode. The antioxidant activities of the ligand and the complexes were performed. Ligand, dcdppz, has no cytotoxicity against the selected cell lines. Complex 1 shows higher cytotoxicity than complex 2, but lower than cisplatin toward selected cell lines. The apoptosis and cell cycle arrest were investigated, and the apoptotic mechanism of BEL-7402 cells was studied by reactive oxygen species (ROS), mitochondrial membrane potential and western blot analysis. Complex 1 induces apoptosis in BEL-7402 cells through ROS-mediated mitochondrial dysfunction pathway and by regulating the expression of Bcl-2 family proteins.

Cytotoxic activity, DNA damage, cellular uptake, apoptosis and western blot analysis of ruthenium(II) polypyridyl complex against human lung decarcinoma A549 cell.

A new ruthenium(II) polypyridyl complex [Ru(dmp)2(pddppn)](ClO4)2Ru1 was synthesized and characterized. The cytotoxic activity in vitro of the complex was evaluated by MTT method. Ru1 shows high effect on the inhibition of the cell growth against BEL-7402, HeLa, MG-63 and A549 cells with low IC50 values of 1.6±0.4, 9.0±0.8, 1.5±0.2 and 1.5±0.3 µM, respectively. The cellular uptake indicates that Ru1 can enter into the cytoplasm and accumulate in the cell nuclei. Ru1 can induce apoptosis in A549 cells and enhance the levels of reactive oxygen species (ROS) and induce the decrease of mitochondrial membrane potential. In addition, Ru1 can down-regulate the levels of Bcl-2, Bcl-x, Bak, and Bim expression and up-regulate the expression of Bag-1 and Bad. The complex induces apoptosis of A549 cells through an intrinsic ROS-mediated mitochondrial dysfunction pathway, which was accompanied by regulating the expression of caspases and Bcl-2 family proteins.

Anticancer activity studies of a ruthenium(II) polypyridyl complex against human hepatocellular (BEL-7402) cells.

A Ru(II) polypyridyl complex [Ru(bpy)2(HMSPIP)](ClO4)2 (1) (bpy=2,2'-bipyridine, HMSPIP=2-(4-methylsulfonyl)phenyl-1H-imidazo[4,5-f][1,10] phenanthroline) was synthesized. The IC50 value of the complex against human hepatocellular cell BEL-7402 is 21.6±2.7 µM. The complex shows no cytotoxic activity toward human lung adenocarcinoma cell A549, human osteosarcoma cell MG-63 and human breast cancer cell SK-BR-3 cells. It is easily for complex 1 to be taken up by BEL-7402 cells. The complex can enhance the reactive oxygen species (ROS) levels and induce the decrease in the mitochondrial membrane potential. The complex inhibits the cell growth in BEL-7402 cells at G2/M phase. Complex 1 can regulate the expression of Bcl-2 family proteins. The results show that the complex induces apoptosis of BEL-7402 cells through a ROS-mediated mitochondrial dysfunction pathway.

Ruthenium(II) polypyridyl complexes induce BEL-7402 cell apoptosis by ROS-mediated mitochondrial pathway.

A new ligand dmdppz and its four ruthenium(II) polypyridyl complexes [Ru(dmb)2(dmdppz)](ClO4)2 (1), [Ru(bpy)2(dmdppz)](ClO4)2 (2), [Ru(phen)2(dmdppz)](ClO4)2 (3) and [Ru(dmp)2(dmdppz)](ClO4)2 (4) (where dmb, bpy, phen, dmp and dmdppz stand for 4,4'-dimethyl-2,2'-bipyridine, 2,2'-bipyridine, 1,10-phenanthroline, 2,9-dimethyl-1,10-phenanthroline and 5,8-dimethoxylpyrido[3,2-a:2',3'-c]phenazine, respectively) have been synthesized and characterized. Their DNA binding behaviors show that the complexes bind to calf thymus DNA by intercalation. The complexes exhibit efficient photocleavage of pBR322 DNA on irradiation. The cytotoxicity of the ligand and the complexes toward HepG-2, HeLa, MG-63, A549 and BEL-7402 were assayed by MTT ((3-(4,5-dimethylthiazo-2-yl)-2,5-diphenyltetrazolium bromide)) method. The IC50 values of the complexes 1, 2, 3 and 4 toward BEL-7402 cells are 14.6, 16.8, 18.0 and 16.7 µM, respectively. Dmdppz shows no cytotoxic activity against selected cell lines. The cellular uptake, apoptosis, comet assay, reactive oxygen species (ROS), mitochondrial membrane potential and western blot analysis were investigated. These results indicate that complexes 1-4 exert their toxicity through the intrinsic ROS-mediated mitochondrial pathway, which is accompanied by the regulation of Bcl-2 family proteins.

Pelopuradazole, a new imidazole derivative alkaloid from the marine bacteria Pelomonas puraquae sp. nov.

One new imidazole derivative alkaloid pelopuradazole (1), together with three known alkaloids as in 3H-imidazole-4-carboxylic acid (2), 1H-pyrrole-2-carboxylic acid (3) and 2-methyl-3H-imidazole-4-carboxylic acid (4) and two known cyclo-dipeptides pelopurin A (5) and pelopurin B (6), has been isolated from the marine bacterium Pelomonas puraquae sp. nov. Pelopuradazole (1) was a new imidazole derivative alkaloid, while compounds 2, 3, 5 and 6 were firstly obtained as natural products. Compounds 1-6 were isolated from P. puraquae sp. nov. for the first time.

Angiopoietin1 inhibits mast cell activation and protects against anaphylaxis.

Since morbidity and mortality rates of anaphylaxis diseases have been increasing year by year, how to prevent and manage these diseases effectively has become an important issue. Mast cells play a central regulatory role in allergic diseases. Angiopoietin1 (Ang-1) exhibits anti-inflammatory properties by inhibiting vascular permeability, leukocyte migration and cytokine production. However, Ang-1's function in mast cell activation and anaphylaxis diseases is unknown. The results of our study suggest that Ang-1 decreased lipopolysaccharide (LPS)-induced pro-inflammatory cytokines production of mast cells by suppressing IκB phosphorylation and NF-κB nuclear translocation. Ang-1 also strongly inhibited compound 48/80 induced and FcεRI-mediated mast cells degranulation by decreasing intracellular calcium levels in vitro. In vivo lentivirus-mediated delivery of Ang-1 in mice exhibited alleviated leakage in IgE-dependent passive cutaneous anaphylaxis (PCA). Furthermore, exogenous Ang-1 intervention treatment prevented mice from compound 48/80-induced mesentery mast cell degranulation, attenuated increases in pro-inflammatory cytokines, relieved lung injury, and improved survival in anaphylaxis shock. The results of our study reveal, for the first time, the important role of Ang-1 in the activation of mast cells, and identify a therapeutic effect of Ang-1 on anaphylaxis diseases.

Synthesis, characterization, cytotoxicity, a poptosis and cell cycle arrest of dibenzoxanthenes derivatives.

Two new dibenzoxanthenes compounds 1 and 2 have been synthesized and characterized by analytical and spectral methods. The crystal structure of compound 2 informs that the five rings of compound are almost planar. The DNA binding properties of two compounds were studied by absorption titration, viscosity measurement and luminescence. These results indicate that two compounds interact with calf thymus DNA through intercalative mode. Agarose gel electrophoresis experiment shows that PBR 322 DNA can be induced to cleave by two compounds under photoactivated condition. Compound 1 exhibits higher cytotoxicity than compound 2 toward MG-63, BEL-7402 and A549 cells. The apoptosis and cellular uptake of MG-63 cells were studied by fluorescence microscopy. Two compounds can also enhance the level of reactive oxygen species (ROS) and decrease the mitochondrial membrane potential. Compound 1 induces cell cycle arrest in G2/M phase and compound 2 induces cell cycle arrest in G0/G1 phase in MG-63.

Ruthenium(II) complexes: DNA-binding, cytotoxicity, apoptosis, cellular localization, cell cycle arrest, reactive oxygen species, mitochondrial membrane potential and western blot analysis.

The aim of our study was to investigate DNA-binding and cytotoxic activity of the four new Ru(II) polypyridyl complexes [Ru(dmb)2(HMHPIP)](ClO4)2 (1), [Ru(bpy)2(HMHPIP)](ClO4)2 (2), [Ru(phen)2(HMHPIP)](ClO4)2 (3) and [Ru(dmp)2(HMHPIP)](ClO4)2 (4). The complexes interact with DNA through intercalative mode and show relatively high cytotoxic activity against A549 cells, no cytotoxicity toward MG-63 cells. Complexes 1-4 can enhance the levels of ROS in A549 cells and induce the decrease of the mitochondrial membrane potential. These complexes inhibit the cell growth in A549 cells at G0/G1 or S phase. Complex 3 activated caspase 7, and down-regulated the expression of the anti-apoptotic protein Bcl-2. Complexes 1-4 induce apoptosis in A549 cells through ROS-mediated mitochondrial dysfunction pathway.

DNA-binding, photocleavage, cytotoxicity in vitro, apoptosis and cell cycle arrest studies of symmetric ruthenium(II) complexes.

Two novel ruthenium(II) complexes [Ru(dmb)2(addppn)](ClO4)2 (1) and [Ru(bpy)2(addppn)](ClO4)2 (2) were synthesized. The DNA-binding constants of complexes 1 and 2 were determined to be 4.78 (±0.49) × 10(5) and 7.42 (±0.53) × 10(5) M(-1). The results indicate that complexes 1 and 2 interact with CT DNA through intercalative mode. The cytotoxicity in vitro of the complexes toward BEL-7402, HeLa, MG-63 and SKBR-3 cells was assessed by MTT assay. The apoptosis was carried out with Hoechst 33258 staining method and flow cytometry. The cellular uptake was observed under fluorescence microscope. The cell cycle arrest shows that the antiproliferative mechanism induced by complexes 1 and 2 on BEL-7402 cells is G0/G1 phase arrest.

Ruthenium(II) polypyridyl complexes: synthesis and studies of DNA binding, photocleavage, cytotoxicity, apoptosis, cellular uptake, and antioxidant activity.

Two ruthenium (II) complexes [Ru(dmb)2(APIP)](ClO4)2 (APIP=2-(2-aminophenyl)imidazo[4,5-f ][1,10]phenanthroline, dmb=4,4'-dimethyl-2,2'-bipyridine; 1) and [Ru(dmb)2(HAPIP)](ClO4)2 (HAPIP=2-(2-hydroxyl-4-aminophenyl)imidazo[4,5-f ][1,10]phenanthroline; 2) were synthesized and characterized. DNA binding was investigated by electronic absorption titration, luminescence spectra, thermal denaturation, viscosity measurements, and photocleavage. The DNA binding constants for complexes 1 and 2 were 4.20 (±0.14)×10(4) and 5.45 (±0.15)×10(4) M(-1). The results suggest that these complexes partially intercalate between the base pairs. The cytotoxicity of complexes 1 and 2 was evaluated by MTT assay. Cellular uptake was observed under fluorescence microscopy; complexes 1 and 2 can enter into the cytoplasm and accumulate in the nuclei. Apoptosis and the antioxidant activity against hydroxyl radicals (•OH) were also explored.

Cytotoxicity, apoptosis, cellular uptake, cell cycle arrest, photocleavage, and antioxidant activity of 1, 10-phenanthroline ruthenium(II) complexes.

Two new ruthenium(II) complexes, [Ru(phen)2(DNPIP)](ClO4)2 (1) and [Ru(phen)2(DAPIP)](ClO4)2 (2), were synthesized and characterized. The DNA-binding properties of these complexes were investigated using UV/vis absorption titration, viscosity measurements, thermal denaturation, and photoactivated cleavage. The DNA binding constants for complexes 1 and 2 are 2.63 ± 0.25×10(5) M(-1) (s=2.45) and 1.51±0.18×10(5) M(-1) (s=1.34). The results indicated that these complexes interacted with DNA through the intercalative mode. The cytotoxicity in vitro of complexes 1 and 2 were assessed against BEL-7402, HepG-2, and MCF-7 cell lines by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Apoptosis was studied with the acridine orange/ethidium bromide staining method. The antiproliferative mechanism was explored with flow cytometry. Cellular uptake studies showed that complexes 1 and 2 can enter into the cytoplasm and accumulate in the nuclei. Cell cycle arrest and antioxidant activity were also investigated.

Synthesis, cellular uptake, apopotosis, cytotoxicity, cell cycle arrest, interaction with DNA and antioxidant activity of ruthenium(II) complexes.

A new ligand and two ruthenium(II) complexes [Ru(bpy)(2)(DNPIP)](ClO(4))(2)1 and [Ru(bpy)(2)(DAPIP)](ClO(4))(2)2 were synthesized and characterized. The DNA-binding constants for complexes 1 and 2 were determined to be 2.24 (±0.30) × 10(5) M(-1) (s = 1.29) and 6.34 (±0.32) × 10(4) M(-1) (s = 2.84). The photocleavage of pBR322 DNA by Ru(II) complexes was investigated. The cytotoxicity of complexes 1 and 2 were assessed against three tumor cell lines. The apoptosis and cellular uptake were studied. The retardation assay of pGL 3 plasmid DNA was explored. The cell cycle arrest was analysized by flow cytometry. The antioxidant activities of the ligand and complexes were also investigated.

Synthesis of ruthenium(II) complexes and characterization of their cytotoxicity in vitro, apoptosis, DNA-binding and antioxidant activity.

A new ligand DBHIP and its two ruthenium (II) complexes [Ru(bpy)(2)(DBHIP)](ClO(4))(2) (1) and [Ru(phen)(2)(DBHIP)](ClO(4))(2) (2) have been synthesized and characterized. The binding behaviors of the two complexes to calf thymus DNA were investigated by absorption spectra, viscosity measurements, thermal denaturation and photoactivated cleavage. The DNA-binding constants for complexes 1 and 2 have been determined to be 8.87+/-0.27 x 10(4)M(-1) (s=1.83) and 1.32+/-0.31 x 10(5)M(-1) (s=1.84). The results suggest that these complexes interact with DNA through intercalative mode. The cytotoxicity of DBHIP, complexes 1 and 2 has been evaluated by MTT assay. The apoptosis assay was carried out with acridine orange/ethidium bromide (AO/EB) staining methods. The studies on the mechanism of photocleavage demonstrate that superoxide anion radical (O(2)(-)) and singlet oxygen ((1)O(2)) may play an important role.