Rhizome essential oil of Curcuma zedoaroides Chaveer. & Tanee: chemical composition, cytotoxic activities, and molecular docking approach

Curcuma zedoaroides Chaveer. & Tanee (Vietnamese name: Nghe &dang) belongs to the Zingiberaceae family which is the new Curcuma species discovered in Thailand and Vietnam in recent years. This study aimed to determine the chemical compositions and the cytotoxic activities of C. zedoaroides rhizome essential oil for the first time. The essential oil was obtained from the rhizomes through hydro-distillation and analyzed by gas chromatography-mass spectrometry (GC-MS) technique. Results showed that the majority of the rhizome essential oil of C. zedoaroides was dominated by oxygenated sesquiterpenes (61.54%) mainly curdione (27.45%), followed by widdrol (8.03%) and trans-beta-elemenone (5.47%). Notably, the essential oil of C. zedoaroides rhizomes exhibited cytotoxic activities using the MTT assay with the IC50 (half-maximal effective concentration) values of 75.16 +/- 2.79, 77.08 +/- 1.98, 81.35 +/- 1.55, 83.67 +/- 2.26, 32.74 +/- 1.95, 23.14 +/- 1.43, 73.35 +/- 2.20 mu g/mL against A549, MCF-7, HepG2, HT29, HL-60, K562 and MDA-MB-231 cells, respectively. In addition, three major compounds targeting specific proteins related to essential oil's anti-cancer activity were assessed using molecular docking simulation. From the results observed, widdrol was suggested to have the highest binding affinity for both EGFR and HER2, with Delta G values of -6.246 kcal/mol and -6.916 kcal/mol, respectively. These results suggest the potential of the rhizome essential oil of C. zedoaroides to provide leads for the development of anti-cancer agents as well as considered a valuable source of bioactive components.