Search

To explore novel antitumor agents with high efficiency and low toxicity, riluzole alkyl derivatives (4a-4i) were synthesized. Their anti-proliferative activities against HeLa, HepG2, SP2/0, and MCF-7 cancer cell lines were assessed by the CCK-8 assay and compared with human normal liver (LO2) cells. Most of them showed potent cytotoxic effects against four human tumor cell lines and low toxic to LO2 cells. In particular, 2-(N-ethylamine)-6-trifluoromethoxy- benzothiazole (4a) showed a IC50 value of 7.76 μmol/L in HeLa cells and was found to be nontoxic to LO2 cells up to 65 μmol/L. Furthermore, flow cytometry indicated that 4a could induce remarkable early apoptosis and G2/M cell cycle arrest in HeLa cells. It also impaired the migration ability of HeLa cells in wound healing assays. Western blot results demonstrated that 4a suppressed Bcl-2 protein expression but increased the level of Bax in HeLa cells, and elevated the Bax/Bcl-2 expression ratio. These new findings suggest that 4a exhibited beneficially anti-cervical cancer effect on HeLa cells by inducing HeLa cell apoptosis.

Ubiquitin–proteasome system (UPS) plays an important role in neurodegenerative diseases, such as Alzheimer’s disease (AD), Parkinson’s disease (PD), and Huntington’s disease (HD). The discovery of UPS activators for anti-neurodegenerative diseases is becoming increasingly important. In this study, we aimed to identify potential UPS activators from our traditional Chinese medicine (TCM) library using the high-throughput screening method with the high-content fluorescence imaging system and validate the neuroprotective effect of the identified UPS activators in cell models of AD. At first, the stable YFP-CL1 HT22 cells were successfully constructed by transfecting the YFP-CL1 plasmid into HT22 cells, together with G418 screening. The degradation activity of the test compounds via UPS was monitored by detecting the YFP fluorescence intensity reflected by the ubiquitin–proteasome degradation signal CL1. By employing the high-content fluorescence imaging system, together with stable YFP-CL1 HT22 cells, the UPS activators were successfully screened from our established TCM library. The representative images were captured and analyzed, and quantification of the YFP fluorescence intensity was performed by flow cytometry. Then, the neuroprotective effect of the UPS activators was investigated in pEGFP-N1-APP (APP), pRK5-EGFP-Tau P301L (Tau P301L), or pRK5-EGFP-Tau (Tau) transiently transfected HT22 cells using the fluorescence imaging, flow cytometry, and Western blotting methods. In conclusion, our study established a high-content fluorescence imaging system coupled with stable YFP-CL1 HT22 cells for the high-throughput screening of the UPS activators. A total of three single compounds, namely, salvianolic acid A (SAA), salvianolic acid B (SAB), and ellagic acid (EA), were identified to significantly decrease YFP fluorescence intensity, which suggests that these three compounds are UPS activators. The identified UPS activators were demonstrated to clear the AD-related proteins, including APP, Tau, and Tau P301L. Therefore, the findings in this study provide a novel insight into the discovery and development of anti-AD drugs.

Exposure to ultraviolet (UV) irradiation leads to the generation of reactive oxygen species (ROS) and DNA damage in skin tissue, which can further result in skin cancers. Using sunscreens is one of the most popular and the most effective method to resist UV irradiation. Resveratrol (RES) shows high absorbance in UV region and significant anti-oxidant effects. However, RES is easily degraded by UV irradiation, resulting in the decrease of bioactivity and the limitation of its application in the pharmaceutical preparations of skin. In this paper, a nanostructured lipid carrier gel loaded with RES (RES-NLC-gel) was prepared to improve the stability of RES and the accumulation of RES in the epidermis. Moreover, RES-NLC-gel could scavenge free radical effectively and protect human keratinocyte from UV irradiation by inhibiting the generation of ROS, decreasing the protein expression of cleaved caspase-3 and Bax and increasing the protein expression of Bcl-2. When mice skin was pretreated with RES-NLC-gel, there were less erythema, wrinkles and scabs on mice skin. The epidermal thickness of mice skins obviously reduced in dose-dependent manner. The activities of catalase (CAT), glutathione peroxidase (GPx) and superoxide dismutase (SOD) in mice skin tissue significantly increased. Thus, RES-NLC-gel exhibited an obvious anti-UV irradiation and anti-oxidant activity in vivo. RES-NLC-gel displayed great application potential in protecting skin from UV irradiation.

Additional file 1. Additional figures and table.