Copper(II) complex enhanced chemodynamic therapy through GSH depletion and autophagy flow blockade.

Three copper(II) complexes C1-C3 were synthesized and fully characterized as chemodynamic therapy (CDT) anticancer agents. C1-C3 showed greater cytotoxicity than their ligands toward SK-OV-3 and T24 cells. Particularly, C2 showed high cytotoxicity toward T24 cells and low cytotoxicity toward normal human HL-7702 and WI-38 cells. Mechanistic studies demonstrated that C2 oxidized GSH to GSSG and produced ˙OH, which induced mitochondrial dysfunction and ER stress, finally leading to apoptosis of T24 cells. In addition, C2 inhibited autophagy by blocking autophagy flow, thereby closing the self-protection pathway of oxidative stress to enhance CDT. Importantly, C2 significantly inhibited T24 tumor growth with 57.1% inhibition in a mouse xenograft model. C2 is a promising lead as a potential CDT anticancer agent.

Copper(II) Complexes of Halogenated Quinoline Schiff Base Derivatives Enabled Cancer Therapy through Glutathione-Assisted Chemodynamic Therapy and Inhibition of Autophagy Flux.

Twelve new complexes Cu(L1)2-Cu(L12)2 were designed and synthesized to improve their chemotherapeutic properties. They showed considerable antiproliferative activity against T24 cancer cells but lower cytotoxicity to human normal cells HL-7702 and WI-38. A mechanism study indicated that Cu(L4)2 and Cu(L10)2 were reduced to Fenton-like Cu+ by glutathione depletion, and the resulting Cu+ catalyzed the generation of highly toxic hydroxyl radicals from excess H2O2. Simultaneously, Cu(L4)2 and Cu(L10)2 could decrease the catalase activity to restrain H2O2 transfer to H2O for enhanced chemodynamic therapy (CDT). These induced mitochondrial dysfunctions and endoplasmic reticulum stress to induce T24 cell apoptosis. In addition, Cu(L4)2 and Cu(L10)2 inhibited autophagy flux to promote cell apoptosis. Cu(L4)2 and Cu(L10)2 demonstrated strong tumor inhibition ability in the T24 xenograft model. Moreover, Cu(L10)2 showed higher antitumor activity and a better safety profile than the CDT agent Cu1. Cu(L10)2 exhibited excellent pharmacokinetic properties. Collectively, Cu(L4)2 and Cu(L10)2 could be developed as potential CDT candidates for cancer treatment.

Chemodynamic therapy agents Cu(II) complexes of quinoline derivatives induced ER stress and mitochondria-mediated apoptosis in SK-OV-3 cells.

Three Cu(II) complexes of quinoline derivatives as cancer chemodynamic therapy agents were synthesized and characterized. These complexes were heavily taken up by cells and reacted with cellular glutathione (GSH) to reduce Cu2+ to Fenton-like Cu+, which catalyzed endogenous H2O2 to produce the highly toxic hydroxyl radicals (•OH) to kill cancer cells. Cu1 and Cu2 initiated CAT activity declines, mitochondrial membrane potential and ATP concentration decrease, mitochondrial Ca2+ overload and ER stress response, leading to cell cycle arrest in sub-G1 and cancer cell caspase-dependent apoptosis. On account of the high GSH and H2O2 specific properties of the tumor microenvironment, Cu1 and Cu2 exhibited higher in vitro anticancer activity and lower toxicity to normal cells. Cu1 and Cu2 efficiently inhibited tumor growth in the SK-OV-3 xenograft mouse model without obvious systemic toxicity.

Pharmacokinetics of Eight Flavonoids in Rats Assayed by UPLC-MS/MS after Oral Administration of Drynariae rhizoma Extract.

As a traditional Chinese medicine, Drynariae rhizoma (Kunze ex Mett.) J. Sm. has been used to treat osteoporosis and bone resorption for 2500 years. Based on the previous study and literature references, flavonoids were proved to be the most abundant and main active compounds of Drynariae rhizoma for osteoporosis treatment. In order to make good and rational use of Drynariae rhizoma in future, a rapid, sensitive, and selective ultraperformance liquid chromatography-mass spectrometry (UPLC-MS/MS) method was developed to investigate the pharmacokinetics of eight main flavonoids in rat plasma after oral administration of the Drynariae rhizoma extract, including neoeriocitrin, luteolin-7-O-ß-D-glucoside, astragalin, naringin, eriodictyol, luteolin, naringenin, and kaempferol. Plasma samples' pretreatment involved a solid-phase extraction column. The separation was performed on an ACQUITY UPLCTM BEH C18 column with a gradient mobile-phase system of acetonitrile and 1% acetic acid in water. The detection was performed using a triple quadrupole tandem mass spectrometer equipped with an electrospray ionization interface (ESI) by multiple reaction monitoring (MRM) in the positive ion mode. All calibration curves exhibited good linearity (r 2 > 0.9990) over the measured ranges. The intraday and interday precisions (RSD) were within 13.87%, and the accuracy (RE) ranged from -14.57% to -0.25% at three quality control levels. Extraction recovery, matrix effect, and stability were satisfactory. The pharmacokinetic characteristics of the eight flavonoids of interest were clearly elucidated.