Research The Combination Cell Toxic And Molecular Machanision Of Baicalin And TRAIL On Lung Cancer Cell Based On Apoptosis

Background and purpose: Lung cancer is one of the most common malignant tumor in the world.Non-small cell lung cancer(NSCLC)account for 85 % of lung cancer.Due to the later appearance of clinical symptoms and presence with non-specific clinical signs,it is hard to diagnose NSCLC at the early stage.Patients with later period of lung cancer have to undergoing chemotherapy or radiotherapy which with severe toxic and side effects but lacking of significant curative effect.Tumor necrosis factor related apoptosis ligand(TRAIL)is a member of tumor necrosis factor(TNF)family.As a new profound potential medicine.TRAIL is often resistanced by NSCLC,the mechanism is still unknown.Baicalin had good therapeutic effects in anti-oxidant,anti-viral,anti-thrombosis,inflammation and so on,which make it an excellent candidate drug for enhancing the anti-tumor effect of TRAIL.This research combined TRAIL and baicalin and applied to the human lung adenocarcinoma cells in vitro,in order to detect the the mechanism of anti-tumor effect.Experimental approach: Cell culture,LDH release assay,immunoblot analysis,detection of ROS and flow cytometry.Key results: Cell death both in NSCLC cells A549 and H2009 were observed under inverted phase contrast microscope and measured by LDH releasing assay.The results showed that different concentrations of Baicalin and TRAIL had more significant synergistic cell death rates than two single drugs with a dose dependent.Flow cytometry analysis showed that Baicalin sensitized TRAIL through apoptosis.LDH releasing assay showed that cell death rates were dropped significantly after treatment with z-VAD-fmk(general caspase inhibitor).Western Blot showed that PARP of combination group was cleavaged.These results indicated that Baicalin sensitized TRAIL through apoptosis pathway.SB203580(P38 inhibitor)pretreatment could distinctly suppress the cell death rate of combined drug group.After 2 and 4 hours treatment,p38 was significantly activated after treatment withTRAIL and baicalin.ROS scavengers BHA and NAC pretreatment significantly suppress the cell death of combined drug group.Meanwhile,ROS signal pathway was activated after 3 hours treatment with TRAIL and baicalin.Conclusions and Implications: In this study,we found that by inducing P38 and ROS signal pathway and activating caspase signal pathway,baicalin greatly sensitized TRAIL induced apoptosis in human NSCLC cell.Our research might provide new insights into lung carcinoma therapy,and find a strategic of the combination of traditional Chinese medicine and targeting drugs.