Phytochemical compositions and cytotoxic activity of Conamomum vietnamense rhizome fractionated extract: in vitro and in silico screenings

Background: Conamomum vietnamense is a new species discovered in Vietnam with important pharmacological potential. Questions: What are the major phytochemical constituents of C. vietnamense rhizomes? Does the n-hexane fraction have cytotoxic effects against five human cancer cell lines (MCF-7, SK-LU-1, HeLa, MKN-7, and HL-60)? Studied species: Conamomum vietnamense N.S.Lý & T.S.Hoang (Zingiberaceae) Study site and dates: Loc Bac, Bao Lam, Lam Dong, Vietnam, 2022-2023 Methods: Volatile components and secondary metabolite groups were identified using gas chromatography-mass spectrometry analysis and color/precipitation reactions, respectively. Rhizome n-hexane fractionated extract of C. vietnamense was tested against cancer cell lines in vitro and in silico. Results: Twenty-three compounds were identified in the rhizome fraction of C. vietnamense, where in α-eudesmol (26.84 %), β-eudesmol (15.02 %), cryptomeridiol (14.36 %), γ-eudesmol (6.21 %), eucalyptol (4.38 %), and eudesm-7(11)-en-4-ol (3.11 %) were proved as major compounds. This n-hexane fractionated extract showed a cytotoxic effect against five human cancer cell lines, namely MCF-7, SK-LU-1, HeLa, MKN-7, and HL-60, with IC50 values varying from 59.04 to 172.43 µg/mL. Along with the in vitro activity test, the docking study demonstrated that α-eudesmol, guaiol, and nerolidol showed the most potential binding affinities to human PTPN2 with binding energies of -29.71, -29.29, and -28.87 kcal/mol, respectively. Furthermore, β-eudesmol, guaiol, and cryptomeridiol exhibited the strongest affinity for the binding site with human IGF-1R kinase with docking scores of -29.29, -28.87, and -32.64 kcal/mol. Conclusions: The current results implied that C. vietnamense rhizomes and its dominant components could be a source of therapeutic interest for cancer.