An isoliquiritigenin derivative inhibited myeloma cells' proliferation and its interactions with human serum albumin

Purpose: In this paper, we reported an isoliquiritigenin (ISL) derivative, namely 1b, which reduced the interleukin-6 (IL-6) expression in RPMI-8226 and CZ-1 cancer cells, thus leading to the cell death. Methods: The growth inhibitory effect of ISL and its derivative 1b was measured on RPMI-8226 and CZ-I cancer cells. To explore the mechanism of cancer cells death, ISL and 1b were used to induce CZ-I cells apoptosis, which was then examined by using the Annexin V-FITC/propidium iodide (PI) kit. Human IL-6 ELISA Kit (ab46042) was used for the quantitative measurement of IL-6 protein in cell culture medium from CZ-1 control cells, or cells treated with ISL and 1b. Results: 1b could induce CZ-1 cells apoptosis in a dose-dependent manner. The pharmacokinetic property of 1b was explored by the interaction of 1b with human serum albumin (HSA). Binding parameters indicated that 1b bound to HSA with binding affinity of the order 10(4) L/mol a moderate binding constant, suggesting 1b could be stored and carried by the protein. Moreover, the binding reaction between HSA and 1b was exothermic, hydrogen bonds and hydrophobic interactions were the predominant intermolecular forces to stabilize the formed 1b -HSA complex. Site markers competitive experiments revealed that 1b bound to both site I and site II of HSA simultaneously. Collectively, our data suggested that 1b could be transferred by HSA to its target for myeloma cell growth inhibitory effects. Conclusions: Our data suggested that 1b could be transferred by HSA to its target for myeloma cell growth inhibitory effects.