The Mechanism Of Active Components Of Traditional Chinese Medicine Oroxin A In Inhibiting Proliferation Of Lung Adenocarcinoma Cells

Background and objectiveOroxylum indicum is the dried seed of Oroxylum indicum(L.)Vent(Bignoniaceae),tasting bitter,sweet and cool,entering lung,liver and stomach.It bears the effect on lung purifing,throat relieving,hustenmildernd and stomach protection.Further more,it has been confirmed that the active components of Oroxylum indicum,such as Flavonoid aglycones,Flavone glycosides and Cyclohexanol,have anti-inflammatory,antimutagenesis and anticancer effects.As a kind of Flavone glycosides extracted from Oroxylum indicum,the role and molecular mechanism of Oroxin A(OA)in inhibiting lung adenocarcinoma proliferation have not yet been illuminated.We used lung adenocarcinoma cell lines for the research to observe the inhibitory effect of OA on cell proliferation,analyze its effect on cell cycle distribution and the expression of cycle regulation protein.Further more,we investigated its effect on the expression and phosphorylation of Akt and STAT3 pathway-related proteins,and approached the molecular mechanism of the inhibitory effect of OA on lungExperiment methodThe lung adenocarcinoma cell lines HCC827,H292,H1299 and H1975 were cultured in vitro.The effect of cell proliferation by OA in different concentrations for 24,48 and 72 hours was analyzed by MTT assay.And in colony forming assay,we investigated its inhibition on cell proliferation.After 24 hours use of OA,the alterations in H1299 and H1975 cycle distribution were detected by PI single staining.By Western blot,we detected the activity of Cyclins,CDKs and p21,which are cycle regulatory proteins in H1299 and H1975,and further explored the expression and phosphorylation level of Akt/GSK3(3 and STAT3 pathway related proteins.ResultThe cell proliferation of lung adenocarcinoma cells was inhibited by OA in a dose-dependent manner,including HCC827,H292,H1299 and H1975,in which H1299 and H1975 cells were relatively sensitive.After OA treated for 24 hours in different concentrations(20,40,80 and 120?M),the survival rates in H1299 cells respectively were 72.8%± 6.2%,61.3%±4.5%,42.0%±4.6%,18.2%±3.1%,and 81.6%±5.3%,70.7%± 4.9%,56.4%± 3.2%,21.6%±3.8%in H1975.After 48 hours treatment,the survival rates in H1299 cells were 68.8%± 5.1%,43.4%± 4.2%,26.2%±4.0%,13.7%±2.4%,and 78.8%± 5.7%,71.4%±5.8%,47.0%± 3.5%,18.5%±3.2%in H1975.After 72h,it came to 60.2%±4.9%,30.7%+5.7%,18.9%± 4.2%,10.5%± 2.3%in H1299,and 53.5%± 5.8%,43.2%± 3.6%,22.2%± 3.4%,13.7%± 2.5%in H1975.In colony forming assay,we found the inhibition effect of OA on cell proliferation.After OA treated for 2 weeks in H1299,there were 185.7 ± 37.6 colony forming units in control group,38.7 ± 27.2 units in 40?M OA group,and 45.7 ± 21.5 units in 80?M OA group,and in H1975,213.5 ± 53.6,34.7 ± 17.1 and 28.9 ± 14.4 units respectively.After OA treated for 24h(40 and 80?M),ratios of H1299 cells in G1 and S phase decreased,and that in G2 phase significantly increased(p<0.05,vs control),the same as H1975 cell line.Treated for 24h(H1299 and H1975),the phosphorylation level of Akt/GSK3?and STAT3 pathway related proteins declined,while no obvious alterations in the expression of these proteins.ConclusionOA could inhibit lung adenocarcinoma proliferation by suppressing the activi ty of Akt/GSK3? and STAT3 pathways,and inducing G2/M phase arrest.