In vitro cytotoxic activity, molecular docking study, and chemical composition of Zingiber cassumunar root oil.

The cytotoxic activities against cancer cell lines of eight known sesquiterpene and phenylbutenoids, namely, (--)-β-sesquiphellandrene (1), (E)-1-(3,4-dimethoxyphenyl)buta-1-ene (2), (E)-1-(3,4-dimethoxyphenyl)buta-1,3-diene (3), (E)-1-(2,4,5-trimethoxyphenyl)buta-1-ene (4), (E)-1-(2,4,5-trimethoxyphenyl)buta-1,3-diene (5), (E)-4-(3,4-dimethoxyphenyl)buta-3-eneyl acetate (6), (±)-trans-3-(3,4-dimethoxyphenyl)-4-[(E)-3,4-dimethoxystyryl] cyclohex-1-ene (7), and (±)-cis-3-(3,4-dimethoxyphenyl)-4-[(E)-3,4-dimethoxystyryl]cyclohex-1-ene (8) were evaluated. All compounds were isolated from the rhizomes of Zingiber cassumunar Roxb. (Plai) using classical column chromatography. Compounds 1, 7, and 8 exhibited good cytotoxic activity against acute lymphoblastic leukemia (MOLT-3) with half maximal inhibitory concentration (IC50) values of 16.39±1.22, 16.41±3.68, and 14.38±0.78 µg/ml; promyelocytic leukemia (HL-60) with IC50 values of 7.64±0.33, 15.25±0.88, and 13.02±0.91 µg/ml; and hormoneindependent breast cancer (MDA-MB-231) with IC50 values of 27.71±1.41, 28.99±2.30, and 27.94±2.24 µg/ml, respectively. Compounds 3, 7, and 8 displayed good anticancer activity against cervical carcinoma (HeLa) with IC50 values of 18.68±0.62, 20.86±1.68, and 18.89±1.26 µg/ml, respectively. The results showed that two diastereomers (7 and 8) have good activity against the broad range of tested cancer cell lines. From molecular docking analysis, the binding energy and interaction between the isolated compounds and topoisomerase II (Top2) was calculated and could be used to evaluate cytotoxic activity. Molecular docking showed that 7 and 8 interacted with Top2 (α and β types) using two or three hydrogen bonding, whereas the other compounds that also displayed this interaction had at least one hydrogen bonding. Additionally, only 7 exhibited non-toxic effect against normal embryonic lung cell line (MRC-5); therefore, the biological activity of 7 can serve as a basis for the study of anti-cancer agents in the near future. [ABSTRACT FROM AUTHOR]