Primary Study Of Antitumor Effect And Mechanism Of Sesamum Inducum L.flower Extract In Vitro

Objective:The purpose is to investigate the antitumor activity of Sesamum inducum L. flower extracts in vitro. The mechanism is explored which the apoptosis of tumor cell line Hela induced by Sesamum inducum L. extract SIA.Methods:The inhibition of various fractions from Sesamum inducum L. flower ethanol extract on tumor cell lines in vitro was determined by MTT assay. The activities of the most effective fraction, SIA, was analyzed on anti-proliferative time-effective and apoptosis induction and cell cycle alteration through the Hoechst 33258 staining and flow cytometric assay. The activity of caspase-3, caspase-8 and caspase-9 in the cells treated by SIA was determined by a caspases colorimetric assay kit. FCM analysis was carried out to examine the Fas protein expression.Results:(1) Cell inhibition in vitro:various fractions from Sesamum inducum L. flower ethanol extract had shown different inhibitory intensity on 4 tumor cell lines (including Hela, CNE-2, KYSE-410 and Smmc-7721), especially the SIA which was separated from the petroleum fraction. SIA had the strongest inhibitory effect on Hela cells dependent on a dose- and time- dependent manner(P<0.05). (2) The cell and nuclear morphological changes were observed under the inverted microscope and fluorescence microscope after treated by SIA for 12 hours and 48 hours respectively. The chromatin of the treated Hela cells pyknosised and some apoptotic body with thick white-blue fluorescent in Hoechst 33258 stained cells were observed. At the concentrations of 50, 100μg/mL, SIA caused a decrease of the percentages of Hela cells in G0/G1 phase. At the same time the apoptosis rate increased significantly (P<0.05), while increase those in S phase (P<0.01). And the percentage of cells in G2/M phase was also decreased. The apoptosis rate increased significantly (P<0.05). The activity of caspase-3, caspase-8 and caspase-9 was increased in a time dependent manner (P<0.05). Protein Fas expression of Hela cells showed a significant increase after treated with SIA for 48h in a dose-dependent manner. Conclusions:(1) The petroleum benzene fraction and diethyl ether fraction from Sesamum inducum L. flower showed antitumor activity against several tumor cell lines. (2) SIA extracted from petroleum benzene fraction had different inhibition on several tumor cells, of which the inhibitory effect on Hela cells were the strongest and were in a dose-and time- dependent manner. (3) SIA can inhibit the proliferation of Hela cells in vitro which may be concerned with inducing cell apoptosis and cell cycle arrest, and the studies demonstrated that the activities of caspase-3, caspase-8 and caspase-9 and Fas protein expression increase may be involved in the pathway of the apoptosis of Hela cells induced with SIA.