Combination of Polygonatum and Scutellaria baicalensis triggers apoptosis through down-regulation of PON3-induced mitochondrial damage and endoplasmic reticulum stress in lung cancer cells

Abstract

Abstract Objective: Scutellaria baicalensis (SB) and polygonatum, two traditional Chinese medinces, are both known to suppress cancer. However, the mechanism and effect of combined treatment of them for lung cancer are rarely known. Investigating the combined effect of SB and polygonatum (hereafter referred to as HH) in potential mechanism of lung cancer is required. Methods: Based on the theory of Chinese medicine and network pharmacology, In the in vivo experiment, a mouse model of carcinoma in situ was constructed and lung carcinoma in situ tissues were collected for proteomics analysis, ematoxylin-eosin staining and CK19 immunohistochemistry. In the in vitro experiment，lung cancer A549 cells at logarithmic growth stage were taken and the inhibitory effect of HH on the proliferation of A549 cells was detected by CCK8 method. The expression of PON3 was detected by quantitative polymerase chain reaction and Western Blot. In addition, the effect of HH on the induction of apoptosis in A549 cells and the changes of membrane potential and ROS content were detected by flow cytometry. The changes of PON3 content in ER is observed by laser confocal microscopy, while the effects of HH on the expression of apoptosis-related proteins and ER stress-related proteins in A549 cells were examined by Western blot. Result: By searching the TCMSP database and symmap database, the respective target genes of the double yellow were mapped into protein network interactions (PPI), and using Venn diagrams to show 38 genes in common between the double yellow and lung cancer, thus HH was found to play a role in the treatment of lung cancer. In vivo experiments showed that in a lung carcinoma in situ model, lung tumor tissue was significantly lower in the HH group compared to the control group, and PON3 was shown to be downregulated by lung tissue proteomics analysis. The combination of HH was able to inhibit the proliferation of A549 cells in a concentration-dependent manner (P < 0.0001). The expression levels of apoptosis-related proteins and ER stress proteins were significantly increased and the expression levels of pon3 and anti-apoptosis-related proteins were decreased in A549 cells. At the same time, knockdown of PON3 could inhibit tumor cell proliferation (P < 0.0001). The combination of different concentrations of HH significantly induced apoptosis in A549 cells (P＜0.05; P＜0.0001), increased ROS content (P＜0.01), and damaged mitochondrial membrane potential of A549 cells (P＜0.05; P＜0.0001), and significantly increased the expression levels of apoptosis-related proteins and ER stress proteins in lung cancer A549 cells. Conclusion：HH inhibits proliferation of lung cancer A549 cells by down-regulating PON3-induced apoptosis in the mitochondrial and ER pathways