An iridium (III) complex as potent anticancer agent induces apoptosis and autophagy in B16 cells through inhibition of the AKT/mTOR pathway.

A new ligand THPDP (THPDP = 11-(6,7,8,9-tetrahydrophenazin-2-yl)dipyrido[3,2-a:2',3'-c]phenazine) and its iridium(III) complex [Ir(ppy)2(THPDP)]PF6 (Ir-1) was synthesized and characterized by elemental analysis, IR, ESI-MS, 1H NMR and 13C NMR. The cytotoxicity in vitro of the complex against cancer cells B16, A549, Eca-109, SGC-7901, BEL-7402 and normal NIH 3T3 cell lines was evaluated using MTT method. The IC50 values of the complex toward B16, A549 and Eca-109 cells are 1.0 ±â€¯0.02, 1.4 ±â€¯0.03 and 1.6 ±â€¯0.06 µM, respectively. The apoptosis was investigated with AO/EB and DAPI staining methods. The complex shows strong ability to inhibit the cell growth in B16, A549 and Eca-109 cells. Ir-1 can induce apoptosis, increase the intracellular ROS level, and cause a decrease in the mitochondrial membrane potential. The intracellular Ca2+ level and the release of cytochrome c were studied under a fluorescent microscope. The cell invasion and autophagy were also performed, and the cell cycle arrest was assayed by flow cytometry. The expression of Bcl-2 family proteins, PI3K, AKT, mTOR, P-mTOR was investigated by western blot. The results show that the complex induces apoptosis through ROS-mediated mitochondria dysfunction and inhibition of AKT/mTOR pathways. These findings are helpful for design and synthesis of iridium(III) complexes as potent anticancer drugs.

Synthesis and anticancer properties of ruthenium (II) complexes as potent apoptosis inducers through mitochondrial disruption.

A new ligand MHPIP (MHPIP = 2-(1-methyl-1H-pyrazol-4-yl)-1H-imidazo[4,5-f][1,10]phenanthroline) and its three ruthenium (II) complexes [Ru(N-N)2(MHPIP)](ClO4)2 (N-N = phen: 1,10-phenanthroline 1; dmp = 2,9-dimethyl-1,10-phenanthroline 2; ttbpy = 4,4'-ditertiarybutyl-2,2'-bipyridine 3) were synthesized and characterized. The cytotoxic activity in vitro was studied by MTT method. The complexes 1-3 show moderate cytotoxic effects on the cell growth in HepG2 cells with an IC50 value of 25.5 ± 3.5, 35.6 ± 1.9 and 27.4 ± 2.3 µM, respectively. The apoptosis was investigated with AO/EB and Annex V/PI staining methods and comet assay. The reactive oxygen species, mitochondrial membrane potential were investigated under a fluorescent microscope. Autophagy assay shows that the complexes can cause autophagy and up-regulate the expression of Beclin-1 protein. Additionally, the complexes inhibit the cell growth in HepG2 cells at G0/G1 phase, and the complexes can regulate the expression of caspase 3 and Bcl-2 family proteins. The studies demonstrate that the complexes induce apoptosis in HepG2 cells through DNA damage and ROS-mediated mitochondrial dysfunction pathways.

Pharmacokinetics of liver-targeted docetaxel liposomes modified with 6-O-acyl-D-galactose esters in rabbits.

The purpose of the present study was to investigate the pharmacokinetics of docetaxel liposomes modified with 6-O-acyl-D-galactose esters (Gal-DOC-L) in rabbits. A simple, rapid and sensitive high-performance liquid chromatography (HPLC) method was developed for the determination of docetaxel. Gal-DOC-L was intravenously administered to rabbits with norethisterone as the internal standard and the blood samples were collected from ear marginal veins at 0.083, 0.25, 0.5, l, 2, 4, 6, 8, 12, 16 and 24 h after treatment. The plasma concentration of docetaxel was determined by HPLC and the pharmacokinetic parameters were calculated. Docetaxel injection (DOC-I) was studied simultaneously. The results showed that the area under the curve(0-∞), t1/2α and t1/2ß of Gal-DOC-L was significantly higher, while the total body clearance was lower than that of DOC-I. The results indicated that Gal-DOC-L was able to maintain a relatively high blood concentration in vivo and prolong the treatment time.

HPLC assay and pharmacokinetics and tissue distribution study of glycyrrhetinic acid liposomes modified with galactosylated lipid.

The aim of this study was to evaluate the pharmacokinetics and tissue distribution of the glycyrrhetinic acid (GA) liposome modified with galactosylated lipid (NOH-GA-LP), compared with GA conventional liposome (GA-LP) and GA solution in mice. The pharmacokinetics and biodistribution of liposomal and solution formulation of GA in mice were studied after intravenous administration. Plasma and tissues were treated using liquid-liquid extraction and determined using reversed-phase high-performance liquid chromatography. Results showed that the mean residence times of NOH-GA-LP (2.99-fold) and GA-LP (2.94-fold) were higher than that of the GA solution in plasma. NOH-GA-LP produced a drug concentration in the liver that was markedly higher than that in other tissues and was approximately 2.0- and 4.8-fold of that of GA-LP and GA solution, respectively. In conclusion, the NOH-GA-LP prepared in this study is a promising sustained-release and drug-targeting system for antitumor drugs.

Preparation and characterization of galactose-modified liposomes by a nonaqueous enzymatic reaction.

In this study, NOH (NOH = N-octadecyl-4-[(D-galactopyranosyl)oxy]-2,3,5,6-tetrahydroxy hexanamide) was enzymatically synthesized as a targeting molecule and incorporated into liposomes to prepare a liposome surface modified with galactose. Glycyrrhetinic-acid-loaded liposome (GA-LP) and glycyrrhetinic-acid-loaded liposome surface modified with galactose (NOH-GA-LP) were prepared by the ethanol-injection method. NOH-GA-LP was characterized by morphology, particle size, zeta potential, encapsulation efficiency, release in vitro, and stability. The size of spherical particles was in the range of 179-211 nm. Spherical particles exhibit a positive electrical charge (38.7 mV) and possess high encapsulation efficiency (91.3%) and show sustained release (72% over 48 hours) in vitro. This novel approach for the liposome surface modified with galactose by enzymatic synthesis is expected to provide potential application as a drug carrier for active targeted delivery to hepatocytes.