The purpose of this paper is to clarify the structure-activity relationship of anti-tumor activity of diosgenin derivatives in vitro. Study has found that diosgenin can inhibit the reproduction of tumor cells by inducing apoptosis and the main target spot of this effect is Bcl-2. Based on the characteristics of pharmacophoric points' of the three-dimensional pharmacophore for Bcl-2 inhibitors, we have docked lots of diosgenin derivatives with Bcl-2, then synthesized 31 compounds of them, finally assessed the anti-tumor activity of the diosgenin derivatives in vitro against A375, A549, HepG-2 and K562. Preliminary studies of SAR have indicated that the aliphatic esters, and aromatic esters of diosgenin without F ring have no anti-tumor activity in vitro. The triazole bromides of diosgenin all achieve fairly good anti-tumor activity in vitro, and those with larger hydrophobic group have the better activity. The stronger is the hydrogen bonding interaction and dipole-dipole interaction of the heterocyclic of diosgenin and diosgenin without F ring and the acid ester of diosgenin without F ring, the better is the activity of derivatives.

Objective: To explore the effect of heme oxygenase-1 (HO-1) on level of reactive oxygen species (ROS) induced by zinc oxide nanoparticles (ZnO-NPs) in Human umbilical vein endothelial cells line EA.hy926. Methods: The EA.hy926 cells in logarithmic growth phase were incubated with 0.0, 2.5, 5.0, 10.0 and 15.0 mg/L ZnO-NPs respectively. The ROS level, reflected by mean fluorescence intensity (MFI), was examined by flow cytometer after 4 hours exposure, the protein expression of HO-1 which was determined by Western Blot after exposed to ZnO-NPs for 24 hours. Cells incubated with 15.0 mg/L were set as the ZnO-NPs group; a blank control group was set at the same time. Cells were pretreated with HO-1 inhibitor zinc protoporphyrin (ZnPPIx) and HO-1 activator cobalt protoporphyrin (CoPPIx), they were classified as ZnPPIx group and CoPPIx group. 15 mg/L ZnO-NPs was chosen to conduct the experiment of HO-1 activation and inhibition. Cells were classified as ZnPPIX+ ZnO-NPs group and CoPPIx+ ZnO-NPs group after pretreated with 10 μmol/L ZnPPIx or CoPPIx for 1 h, added 15 mg/L ZnO-NPs to cell culture medium. In all groups ROS levels were detected after exposed to ZnO-NPs for 4 hours, the protein expression of HO-1 was detected after exposed to ZnO-NPs for 24 hours. Results: With the increased dose of ZnO-NPs, levels of ROS and HO-1 in EA.hy926 cells were clearly elevated (the MFI of 0.0, 2.5, 5.0, 10.0 and 15.0 mg/L ZnO-NPs incubated groups was 22 627.22±718.27, 24 726.47±568.52, 31 141.75±1 312.24, 39 824.82±4 774.74, 50 569.03±1 497.63 respectively, and HO-1 relative expression were 0.16±0.01, 0.19±0.02, 0.16±0.01, 0.23±0.02, 0.92±0.06 respectively). HO-1 expression in ZnPPIx pretreatment group decreased compared with ZnO-NPs group (1.05±0.05 vs. 1.12±0.01, P<0.05), meanwhile ROS level enhanced (62 683.95±2 589.59 vs. 53 654.53±2 229.01, P<0.05). However, CoPPIx pretreatment had higher HO-1 level and lower level of ROS compared with ZnO-NPs group (HO-1: 1.74±0.11 vs. 0.22±0.03, P<0.05; ROS: 32 845.04±993.48 vs. 53 654.53±2 229.01, P<0.05). Conclusions Exposure to ZnO-NPs significantly induced ROS generation in EA.hy926 cells in a dose-dependent manner. HO-1 regulated ZnO-NPs-induced oxidative stress.

In recent years, iron has been regarded as a common pathological feature of many neurodegenerative diseases, including Alzheimer's disease (AD), Parkinson's disease (PD) and Friedreich's ataxia (FRDA). A number of genes involved in iron transport, storage and regulation have been found associated with initiation and progression of neurodegeneration. However, whether iron abnormalities represent a primary or secondary event still remains unknown. Due to the limitation in transgenic rodent model construction and transfection systems, the progress in unraveling the pathogenic role of different iron-related proteins in neurodegenerative diseases has been slow. Drosophila melanogaster, a simple organism which has a shorter lifespan and smaller genome with many conserved genes, and captures many features of human nervous system and neurodegeneration, may help speed up the progress. The characteristics that spatial- and temporal-specific transgenic Drosophila can be easily constructed and raised in large quantity with phenotype easily determined turn Drosophila into an excellent in vivo genetic system for screening iron-related modifiers in different neurodegenerative conditions and hence provide a better picture about the pathogenic contribution of different iron-related protein abnormalities. It is believed that identification of important iron-related genes that can largely stop or even reverse degenerative process in Drosophila models may lead to development of novel therapeutic strategies against neurodegenerative diseases.
Alzheimer Disease ; physiopathology ; Animals ; Disease Models, Animal ; Drosophila melanogaster ; Friedreich Ataxia ; physiopathology ; Humans ; Iron ; Neurodegenerative Diseases ; physiopathology ; Parkinson Disease ; physiopathology

Objective To explore the effect of L-ascorbic acid(AA) for reducing the fibroblast cells induced by cobalt(co)cytotoxicity.Methods The experiment was divided into the blank control group,Co2+ group,Co2++AA group,cobalt nanoparticles(CoNPs) group,CoNPs+AA group and AA group.The AA pretreated for 1 h was performed in advance.The CCK8 assay was used to detect the CoNPs and Co2+ induced and AA-treated cytotoxicity.The fluorescence staining was used to measure the production of ROS in mitochondria.The real-time polymerase chain reaction(PCR) and Western blot were used to measure the expression of related protein and related molecular mRNA respectively.Moreover the cytochrome-C level in cytoplasml was detected.Results After treating the cells by CoNPs and Co2+,the cells appeared apoptosis.CoNPs could significantly induce ROS generation;the proapoptotic factors(caspases-3,and Bax) were significantly increased,while the anti-apoptotic factor Bcl-2 expression was decreased;cytochrome C and AIF expressions were up-regulated and released from mitochondria into the cytoplasm,after AA pretreatment,these changes caused by CoNPs were decreased.Conclusion AA can reduce the CoNPs caused cytotoxicity by reducing ROS generation and release,but can not weaken the Co2+ toxic effect.