Isolation and characterisation of secondary metabolites from Trifolium vesiculosum Savi and their antiproliferative activities

Abstract

One unreported flavonol namely morin-7-O-methyl ether (1) along with seven known compounds were isolated from the aerial parts of Trifolium vesiculosum Savi which were elucidated by using extensive spectroscopic methods such as 1D and 2D NMR and HR-MS. According to the cell viability assay (MTS) on the purified compounds (1-8), quercetin-3-O-(6’’-trans-p-coumaroyl)-β-galactoside (4) revealed remarkable antiproliferative activity most particularly against breast cancer cells (IC50 = 2.90 ± 0.25 µM in HCC1937 and 7.98 ± 0.57 µM in MCF7) while moderate inhibitory activity (IC50 = 17.96 ± 0.51-51.70 ± 2.69 µM) on prostate, colorectal and liver cancer cell viability was observed. Further mechanistic examinations (Annexin V/PI staining, DNA content and detection of reactive oxygen species analyses) showed that compound 4 significantly induced apoptosis, enhanced mitochondrial reactive oxygen species (ROS) accumulation, and caused cell cycle arrest in cancer cells by increasing accumulation of cells at G0/G1 and/or G2/M phases of the cell cycle.