Antiproliferative Effect of Lignosus rhinocerotis, the Tiger Milk Mushroom on HCT 116 Human Colorectal Cancer Cells

Abstract

Tiger Milk mushroom is a unique mushroom that has number of medicinal properties. Communities in Malaysia have been using this mushroom to treat different kinds of cancer. This study was conducted to elucidate the antiproliferation activity of this national treasure mushroom on human colorectal cancer cells (HCT 116). Colon cancer cells were cultured in the presence of L. rhinocerotis for aqueous or methanol pressurized liquid extraction (PLE) at various concentrations for 24 hours. The percentage of cell viability was determined by 3-(4, 5-dimethylthiazol-2-yl)-2, 5- di phenyl tetrazolium bromide (MTT) assay. Our results showed that methanol PLE of Lignosus rhinocerotis sclerotia was found to exhibit antiproliferative activity against HCT 116 cells, with an IC50 of 600 µg/mL and 1200 µg/mL for aqueous PLE. In comparison, both extractions did not show significant cytotoxicity against normal human colon cell (CCD- 18CO). The IC 50 values suggested that the solvent differences in pressurized liquid extraction greatly affected their antiproliferative activites. Additionally, weak antioxidant capacities were detected in both methanol and aqueous PLE of L. rhinocerotis by the FRAP (Ferric Reducing Antioxidant Power) Assay. However, this capacity was not significant when the aqueous extract was tested in the presence of HCT 116 cells. Preliminary phytochemical screening revealed that both methanol and aqueous pressurized liquid extraction of L. rhinocerotis contained alkaloids.