Preliminary investigation of in vitro anti-proliferative effects of ethanolic plant extract of hypoxis argentea in colon carcinoma cell lines

Abstract

Colorectal cancer (Caco-2) is the third most common cancer with a high mortality rate worldwide. The current therapeutic approaches, such as radiotherapy and chemotherapy, are characterized by several limitations. The search for alternatives has led to the use of medicinal plants such as Hypoxis argentea. This study aimed to investigate the anti-proliferative effects of ethanolic plant extract of Hypoxis argentea in colon carcinoma cell lines. Ethanolic extract of Hypoxis argentea, Caco-2 cell lines, Vero cell lines, and melphalan (positive control) were used for this study. The antioxidant potential of the extract was evaluated using the DPPH assay. The MTT assay and total cell count were performed to determine cell metabolic activity, viability, and cell proliferation in both cell lines with varying concentrations of H. argentea extract (15.6 to 500 µg/mL) and a reference chemotherapeutic agent, melphalan (6.25 to 100 µM). Treatment with H. argentea revealed a significant (P<0.01) dose-dependent decrease in cell viability in Caco2 cancer and Vero cells at concentrations 15.6-62.5 µg/mL. Also, the total cell count of Vero and Caco-2 cells was significantly reduced (p<0.01) compared to the control at every dose concentration of Hypoxis argentea. Likewise, the total cell count of Vero and Caco-2 cells was significantly reduced (p<0.01) compared to the control at every dose concentration of melphalan.  These findings indicate that H. argentea has a promising selective antiproliferation effect on cancer cells while maintaining a safe profile for normal cells.