Triterpenoid saponins from the rhizomes of Anemone flaccida and their inhibitory activities on LPS-induced NO production in macrophage RAW264.7 cells.

A new ursane-type triterpenoid saponin, flaccidoside IV (1), and three new oleanane-type triterpenoid saponins, flaccidosides V-VII (2-4), along with 17 known saponins (5-21), were isolated from the rhizomes of Anemone flaccida. The structures of the new triterpenoid saponins were determined based on spectroscopic analyses and chemical methods. All the isolated saponins were tested for their inhibitory activities on lipopolysaccharide-induced nitric oxide production in RAW264.7 macrophages, and several bisdesmosidic oleanane-type triterpenoid saponins (2, 7, and 10) showed significant inhibitory activities, which indicated they had potential anti-inflammatory activities under their noncytotoxic concentrations in vitro.

Overexpression of DNA damage-induced 45 α gene contributes to esophageal squamous cell cancer by promoter hypomethylation.

BACKGROUND: Environmental factors-induced dysfunction of esophageal squamous epithelium, including genomic DNA impairment and apoptosis, play an important role in the pathogenesis of esophageal squamous cell cancer. DNA damage-induced 45α (GADD45α) has been found promoting DNA repair and removing methylation marker, Therefore, in this study we will investigate whether GADD45α expression is induced and its mechanism in esophageal squamous cell cancer. METHODS: Two human esophageal squamous cell lines (ESCC), ECA109 and KYSE510 were cultured in RPMI-1640 medium supplemented with 10% fetal bovine serum (FBS). Lipofectamine 2000 was used to transfect cells. mRNA level of GADD45α was measured by reverse transcription-quantitive PCR (RT-qPCR), protein level of GADD45α was detected by western blot and Immunohistochemistry. Global DNA methylation of tissue sample was measured using the Methylamp Global DNA Methylation Quantification Ultra kit (Epigentek Group) and promoter methylation was measured by bisulfite sequencing. RESULTS: GADD45a mRNA and protein levels were increased significantly in tumor tissue than that in adjacent normal tissue. Hypomethylation of global genomic DNA and GADD45α promoter were found in ESCC. The cell sensitivity to Cisplatin DDP was decreased significantly in Eca109 and Kyse510 cells, in which GADD45α expression was down-regulated by RNA interference (RNAi). In addition, silence of GADD45a expression in ESCC cells inhibited proliferation and promoted apoptosis. CONCLUSION: Overexpression of GADD45α gene is due to DNA hypomethylation in ESCC. GADD45α may be a protective factor in DDP chemotherapy for esophageal squamous cell carcinoma.

[In vitro gene transfection by magnetic iron oxide nanoparticles and magnetic field increases transfection efficiency].

OBJECTIVE: To evaluate the feasibility of using iron oxide nanoparticles as gene vector and the effect of magnetic field on efficiency of transfection. METHODS: Iron oxide nanoparticles were prepared by alkaline precipitation of divalent and trivalent iron chloride. The surface of iron oxide nanoparticles was modified by self-assembled poly-L-lysine to form particle complexes (IONP-PLL). Transfection was determined by delivering reporter gene, PGL2-control encoding luciferase, to different cell lines using IONP-PLL as vector. The effect of magnetic field on efficiency of transfection was determined using Nd-Fe-B permanent magnet. RESULTS: Foreign gene could be delivered to various cell lines by IONP-PLL and expressed with high efficiency, but the transfection efficiency and time course varied in the different cell lines studied. Magnetic field could enhance the efficiency of transfection by 5 - 10 fold. CONCLUSION: IONP-PLL can be used as a novel non-viral gene vector in vitro, which offers a basis for gene delivery in vivo.

IONP-PLL: a novel non-viral vector for efficient gene delivery.

BACKGROUND: Non-viral methods of gene delivery have been an attractive alternative to virus-based gene therapy. However, the vectors that are currently available have drawbacks limiting their therapeutic application. METHODS: We have developed a self-assembled non-viral gene carrier, poly-L-lysine modified iron oxide nanoparticles (IONP-PLL), which is formed by modifying poly-L-lysine to the surface of iron oxide nanoparticles. The ability of IONP-PLL to bind DNA was determined by ratio-dependent retardation of DNA in the agarose gel and co-sedimentation assay. In vitro cytotoxic effects were quantified by MTT assay. The transfection efficiency in vitro was evaluated by delivering exogenous DNA to different cell lines using IONP-PLL. Intravenous injection of IONP-PLL/DNA complexes into mice was evaluated as a gene delivery system for gene therapy. The PGL2-control gene encoding firefly luciferase and the EGFP-C2 gene encoding green fluorescent protein were used as marker genes. RESULTS: IONP-PLL could bind and protect DNA. In contrast to PLL and cationic liposomes, IONP-PLL described here was less cytotoxic in a broad range of concentrations. In the current study, we have demonstrated that IONP-PLL can deliver exogenous gene to cells in vitro and in vivo. After intravenous injection, IONP-PLL transferred reporter gene EGFP-C2 to lung, brain, spleen and kidney. Furthermore, we have demonstrated that IONP-PLL transferred exogenous DNA across the blood-brain barrier to the glial cells and neuron of brain. CONCLUSIONS: IONP-PLL, a low-toxicity vector, appears to have potential for fundamental research and genetic therapy in vitro and in vivo, especially for gene therapy of CNS disease.