Ma Xiao-yao,Zhang Man,Fang Ge,Cheng Chuan-jing,Wang Mu-kuo,Han Yi-man,Hou Xiao-tao,Hao Er-wei,Hou Yuan-yuan,Bai Gang
Alcoholic liver disease (ALD) is one of the pathogenic factors of chronic liver disease with the highest clinical morbidity worldwide. Ursolic acid (UA), a pentacyclic terpenoid carboxylic acid, has shown many health benefits including antioxidative, anti-inflammatory, anticancer, and hepatoprotective activities. We previously found that UA was metabolized in vivo into epoxy-modified UA containing an epoxy electrophilic group and had the potential to react with nucleophilic groups. In this study we prepared an alkynyl-modified UA (AM-UA) probe for tracing and capturing the target protein of UA from liver in mice, then investigated the mode by which UA bound to its target in vivo. By conducting proteome identification and bioinformatics analysis, we identified caspase-3 (CASP3) as the primary target protein of UA associated with liver protection. Molecule docking analysis showed that the epoxy group of the UA metabolite reacted with Cys-163 of CASP3, forming a covalent bond with CASP3. The binding mode of the UA metabolites (UA, CM-UA, and EM-UA) was verified by biochemical evaluation, demonstrating that the epoxy group produced by metabolism played an important role in the inhibition of CASP3. In alcohol-treated HepG2 cells, pretreatment with the UA metabolite (10 μM) irreversibly inhibited CASP3 activities, and subsequently decreased the cleavage of PARP and cell apoptosis. Finally, pre-administration of UA (20–80 mg· kg −1 per day, ig, for 1 week) dose-dependently alleviated alcohol-induced liver injury in mice mainly via the inhibition of CASP3. In conclusion, this study demonstrates that UA is a valuable lead compound for the treatment of ALD.
Bo Yu,Hong Li,Jinhui Zhang,Wenjie Zheng,Tianfeng Chen
The rational design and fabrication of nanodelivery systems to encapsulate drugs has been proven to be a promising and effective strategy for cancer therapy. Selenocystine (SeC), a naturally occurring selenoamino acid, has received more and more attention due to its novel pharmacological properties in the treatments of cancers. In this study, we fabricated a cancer-targeted nanodrug delivery system by encapsulating SeC into chitosan (CS) nanoparticles with folate surface decoration (FA–SeC–CSNPs) and evaluated its antiproliferative activities. The nanosystem entered the cells through endocytosis and released SeC in lysosomes under an acidic environment. Compared with SeC–CSNPs and SeC, FA–SeC–CSNPs significantly inhibited the growth of HeLa human cervical cancer cells that overexpressed folate receptors through the induction of apoptosis with the involvement of PARP cleavage and caspase activation. Moreover, FA–SeC–CSNPs also significantly suppressed the migration and invasion of HeLa cells in a dose-dependent manner. Furthermore, the intracellular nanosystem triggered the overproduction of reactive oxygen species (ROS) as early as 25 min after treatment, which activated various downstream signaling pathways such as p53, AKT and MAPKs to induce the cell death. Taken together, this study demonstrates a strategy for rational design of a cancer-targeted nanosystem loaded with selenocompounds to achieve selective cellular uptake and enhanced anticancer efficacy.
危险品化学品经营许可证（带存储）