ABSTRACT
ObjectiveTo investigate the effects of the volatile oil of Linderae Radix on the apoptosis and autophagy of human gastric cancer cell line AGS， and to explore the regulatory role of adenosine monophosphate-activated protein kinase （AMPK）/mammalian target of rapamycin （mTOR） signaling pathway in this process. MethodThe volatile oil of Linderae Radix was extracted by steam distillation， and the effect of the volatile oil on the viability of AGS cells was detected by thiazolyl tetrazolium （MTT） colorimetry. The optimal intervention dose and time were determined according to the half maximal inhibitory concentration （IC50） for subsequent research. The blank， low， medium， and high-dose volatile oil （0， 15， 30， 60 mg·L-1） groups and the positive drug cyclophosphamide （CTX， 350 mg·L-1） group were designed. AGS cells were treated with different doses of volatile oil for 48 h. The changes in cell proliferation， cycle， and migration were measured by colony formation assay， flow cytometry， and cell scratch test， respectively. Hematoxylin-eosin （HE） staining was employed to observe the changes of cell morphology， Annexin-V/propidium iodide （PI） double staining to measure the apoptosis， and acridine orange （AO） staining to measure the autophagy level of the cells. Western blotting was employed to determine the expression of the autophagy effectors Beclin-1， p62， microtubule-associated protein 1-light chain 3 （LC3）， B-cell lymphoma-2 （Bcl-2）， Bcl-2-associated X protein （Bax）， cleaved Caspase-3， cleaved poly ADP-ribose polymerase （PARP）， adenosine monophosphate-activated protein kinase （AMPK）， phosphorylated AMPK （p-AMPK）， mTOR， and phosphorylated mTOR （p-mTOR）. ResultCompared with the blank group， 24 h and 48 h of intervention with the volatile oil of Linderae Radix inhibited the viability of AGS cells in a concentration- and time-dependent manner （P<0.05， P<0.01）. Compared with the blank group， the volatile oil decreased the cell proliferation and migration （P<0.05， P<0.01） and blocked the AGS cell cycle in G2/M phase （P<0.05， P<0.01） in a concentration-dependent manner. The cells treated with the volatile oil became spherical and smaller， with the formation of apoptotic bodies and increased apoptosis rate （P<0.05， P<0.01）. As the dose of the volatile oil increased， the number of autophagosomes increased and the red fluorescence gradually enhanced， indicating the elevated level of autophagy. Compared with the blank group， different doses of volatile oil up-regulated the protein levels of Beclin-1， LC3 Ⅱ/LC3 Ⅰ， cleaved Caspase-3， cleaved PARP， Bax/Bcl-2， and AMPK （P<0.05， P<0.01） and down-regulated the protein levels of p62 and p-mTOR （P<0.05， P<0.01）. ConclusionThe volatile oil of Linderae Radix induces the apoptosis and exerts the autophagy-mediated growth inhibition of AGS cells by regulating the AMPK/mTOR signaling pathway.
ABSTRACT
Exosome is a kind of vesicle secreted by a variety of cells with lipid bilayer membrane structure， which has good biocompatibility， high targeting and high stability， and is a natural nanoscale drug carrier with great development potential in drug delivery system. In this paper， exosomes and their properties， exosome drug delivery pathways and methods， the design strategy of engineered exosome drug delivery systems for targeted disease therapy， and the application of exosome drug delivery systems in the treatment of a variety of diseases were reviewed. Exosome drug delivery pathways could be divided into two categories： exogenous and endogenous. Common exosome drug delivery methods included electroporation， co-incubation， and ultrasound. Engineered exosome drug delivery system can further improve drug loading and enhance drug targeting. The main way of engineering is to modify exosome surface through genetic engineering technology， physical modification， chemical modification， etc. Exosome drug delivery system provides a new idea for targeted therapy of arthritis， tumor， brain and other diseases.