RETRACTED: In Vitro Antitumor Activities of Biologically Active Extracts and Isolated Phytochemicals From Rabdosia latifolia C. Y. Wu Et H. W. Li in Addenda (Retracted article. See vol. 18, 2023)

To investigate the antitumor activities, as well as phytochemical constituents of Rabdosia latifolia C. Y. Wu et H. W. Li in Addenda (R. latifolia) extracts, the light petroleum, dichloromethane, ethyl acetate, n-butanol, and water extracts from R. latifolia were determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays on MCF-7, HepG2, A549, Hela, and BGC-823 cells. We further examined cell cycle and apoptosis of the biologically active extracts on MCF-7 cells. The constituents of the biologically active extracts were determined using ultra-performance liquid chromatography/quadrupole time-of-flight mass spectrometry (UPLC-Triple-TOF/MS) and gas chromatography-mass spectrometric (GC-MS) analysis. MTT assays showed that the dichloromethane extract had an inhibitory effect on MCF-7 and BGC-823 cells and that at 50 mu g/mL showed 9.9% +/- 1.7% inhibition of MCF-7 cells and 81.7% +/- 9.5% of BGC-823 cells, respectively. The data for cell cycle analysis clearly showed a significant block in the S-phase. The dichloromethane extract induced apoptosis of MCF-7 cells, and the cell apoptosis rate showed time and concentration effects. UPLC- Triple-TOF/MS analysis revealed the presence of 16 structurally characterized compounds in the dichloromethane extract, all of which were identified for the first time in this species. Ent-kauranoids, such as henryin (9) and its analogs, were the predominant compounds. Subsequently, GC-MS analysis showed the presence of 20 volatile compounds, including gamma-sitostenone, beta-amyrone, gamma-tocopherol, and dotriacontane. Based on the results of this study and previous literature reports, it is concluded that the ent-kauranoids, such as henryin, were the predominant components of R. latifolia with antitumor activity.