The Mechanism Of Inhibitory Effect Of Nobiletin On Human Non-small Cell Lung Cancer Cell Line A549

Objective To investigate the inhibitory effect of nobiletin (5,6,7,8,3'4'-hexamethoxyflavone) on human non-small cell lung cancer cell line A549 and its mechanism of action. Methods The inhibitory effect of nobiletin on proliferation of A549 cells was evaluated by MTT analysis, growth curve and clone-forming assay. A549 was treated with nobiletin at the dose 2,4,8,16,32,64,128 μg/ml in MTT assay to analyze the inhibitory effect on proliferation of A549 cells and IC₅₀ was calculated;After treated with nobiletin at the dose 25 μg/ml,50 μg/ml,0.1 μg/ml Adriamycin as positive control for 5 days, growth curve of A549 cells was completed. For clonogenic assay,cells were exposed to nobiletin at the dose 10 μg/ml,20 μg/ml,40 μg/ml for 24h,0.1 μg/ml Adriamycin as positive control, the inhibitory rate of clone-forming was calculated.Its apotosis-inducing effect was approved by morphological observation under microscope (Giemsa staining and hoechst 33258 fluorescent staining), electron microscope and agarose gel electrophoresis. The protein expressions of Bax and Bcl-2 gene were analyzed by flow cytometric analysis. Results After treated with nobiletin for 24,48,72 hours, MTT assay showed that nobiletin at the dose ranging from 4 μg/ml to 128 μg/ml had the inhibitory ratio ranging from 8% to 85%. IC₅₀ of nobiletin to A549 in 24h,48h and 72h were 38.2 μg/ml, 25.7 μg/ml and 16.7 μg/ml respectively; The inhibitory rate of...