Black Rice Extract Induced Apoptosis and Cell Cycle Arrest on Human Cancer Cell Lines

Abstract

The purpose of the research is to evaluate the anti-cancer outcomes of aqueous black rice (BR) extract on human cancer cell lines; HeLa, T47D, and U2OS. To begin the investigation, the total phenol and flavonoid content of the BR extract was determined. Additionally, the antioxidant activity of the extract was determined using the ferric reducing antioxidant power (FRAP), total antioxidant capacity (TAC), and 2, 2-Diphenyl-1-picrylhydrazyl (DPPH) assays. The cell viability, apoptosis and cell cycle on several human cancer cells were determined after BR extract administration in several doses (BR1; 100 mg/ml, BR2; 200 mg/ml, BR3; 300 mg/ml, BR4; 400 mg/ml, and BR5; 500 mg/ml) using flow cytometry analysis. According to the analysis, the extract had total phenol and flavonoid content are 66.42 mg/g and 11.12 mg/g, respectively. Based on the assay of DPPH (53.19 µg/ml), FRAP (49.86 mg/g), and TAC (96.70 mg/g), BR extract showed strong antioxidant activity. This study also revealed that BR extract significantly reduced human cancer cell lines viability and selectively (shown to have no effect on PBMC cells) (p<0.05) especially BR5 group (500 g/mL) . The administration of BR extract was most responsive to induce apoptosis in T47D cells, up to 93.64 % in BR5 close to cisplatin-induced apoptosis effect, compared to HeLa and U2OS cells. The study also found BR extract induced the cell (HeLa, T47D, and U2OS) to arrest or in the phase G0/G1. Hence, BR extract was a food-based cancer treatment with a promising effect to inhibit cancer cell growth and progression.