Abstract
Introduction: Kinase enzymes play an important role in cellular proliferation, the main target in cancer treatment is to inhibit their functions. Protein kinase inhibitors as flavonoids can be applied for prevention or treatment of cancers through inhibition of cell proliferation. Objectives: To isolate cytotoxic metabolites from B. eriophora, evaluate their antiproliferative and protein kinase inhibitory effects, as well as the in silico study for active compounds. Materials and Methods: Preparative HPLC was used for purification of the isolates. NMR, MS and UV spectroscopy were applied for characterization of the pure compounds. Sulphorhodamine-B and radiometric assay methods were employed for determination of the antiproliferative and protein kinase inhibition activities, respectively. The antiproliferative mechanism was predicted by in silico study using Molecular Operating Environment (MOE). Results: Five flavonoids; luteolin, acacetin-7-O-beta-D-glucoside, diosmin, kaempferol-3-O-rutinoside and rutin were isolated and investigated for their antiproliferative and kinase inhibitory effects. Luteolin exhibited strong antiproliferative effect against certain cell lines including MCF-7, HepG2 and HCT-116 with IC 50 (33.24 +/- 0.83, 26.54 +/- 1.02 and 31.62 +/- 1.32 mu M, respectively), while diosmin and kaempferol3-O-rutinoside showed strong antiproliferative effect against MCF-7 with IC 50 (26.56 +/- 1.12 and 28.72 +/- 0.98). Luteolin showed highest inhibitory effect against Aurora B and CDK4/CyclinD1 with IC 50 3.16 and 4.95 m3.16 and 4.95 inhibitin slico study for the isolated metabolites against Aurora B and CDK4/CycD1 confirmed their cytotoxic profile. Conclusion: Five flavonoids were firstly isolated from B. eriophora. The putative antiproliferative mechanism of luteolin and kaempferol-3- O- rutinoside on Aurora B and CDK4/CycD1 kinases was predictable by in slico study.