Evaluation of in vitro anti-cancer effects of Styphnolobium japonicum root extract in human colon (HT-9), brain (U-87), and prostate (PC-3) cancer cell lines

Abstract

Background and Aims: Styphnolobium japonicum (L.) Schott. (Sophora japonica) is a medicinal plant applied for various diseases, in the traditional medicine field. The evaluation of methanol extract of S. japonicum root derived from the Pharma Grade plant drug, was performed in terms of various in vitro biological activities.Methods: The LC-MS analysis was used for the chemical characterization of the methanol extract. The anti-cancer activity was evaluated in colon (HT-9), brain (U-87), and prostate (PC-3) cancer cells by Cell Titer Glo viability assay (Promega) and western blot analysis of PARP (Poly ADP-ribose polymerase) cleavage.Results: The relative amounts of matrine and oxymatrine in the extract were found as 0.49 +/- 0.006 mg/mL and 0.27 +/- 0.016 mg/mL, respectively. The S. japonicum extract showed 53.17 +/- 0.97 mg of gallic acid (GA)/g corresponding to the total phenolic amounts, resulting in relatively moderate antioxidant activity (1.94 +/- 0.23 and 2.79 +/- 0.15 mg/mL) on the in vitro2,2'-azino-bis(3ethylbenzothiazoline-6-sulfonic acid (ABTS center dot) and 2,2-diphenyl-1-picrylhydrazyl (DPPH center dot) assays. Treatment with 10 mg/mL S. japonica root extract for 24h resulted in a significant decrease in cell viability. The cell viability of U-87, HT-29, and PC-3 cancer cell lines was determined as 35 +/- 2.21%, 14 +/- 2.11%, and 46 +/- 5.67%, respectively. The extract showed 5.104, 5.012 and 0.555 mg/mL IC50 values for HT-29, U-87, and PC-3 cell lines, respectively. Particularly, the IC50 value of PC-3 cancer cell line was significantly lower than the healthy human fibroblast cells. In further, the apoptosis in S. japonicum root extract treated PC-3 cells was detected through flow cytometry analysis of Annexin V positive cells and western blot analysis of PARP cleavage.Conclusion: It can be concluded that the methanol extract in determined doses induces the apoptosis of the PC-3 cancer cells, without any significant cytotoxic effect on healthy human fibroblast cells. In addition, the LCMS analysis showed the presence of matrine and oxymatrine, which are known for their anticancer activity. To the best of our knowledge, these are the first preliminary results indicating the possible use of S. japonicum root extract. Thus, the methanol extract can be further studied for its therapeutic potential of primarily prostate and other cancer types.