Induction of Apoptosis in DLD-1 Colorectal Cancer Cells using Water Soluble Compounds from Rumex Crispus

In this study, water soluble compounds from R. crispus root and leaf were extracted, purified and separated using reversed phase High Performance Liquid Chromatography (HPLC). Cell viability assays were performed on human colorectal adenocarcinoma (DLD-1 ATCC® CCL-221TM) cells for each fraction and were further screened for caspase 3/7 activity to show that cell death was through apoptosis. R-26, L-26 and L-19 fractions from HPLC exhibited cell viability reduced to 8.7 %, 10 % and 9.8%, respectively. The caspase-3/7 fold change was observed to be 12.3, 3.5 and 26.9 fold increase for R-26, L-26 and L-19 respectively, compared to untreated cells. mRNA from L-19 treated cells was used to determine caspase 3,7,8, 9 and 10 levels of gene expression by qRT-PCR.  The ΔΔCt values for each caspase was determined using GAPDH for normalization.  The ΔΔCt values for initiator caspases 8 and 10 were found to be 3.0 and 6.5 fold higher relative to untreated cells respectively.  The initiator caspase-9 showed no change. These results suggest the extrinsic pathway of apoptosis to be involved. Gas chromatography-Mass Spectrometry (GC-MS) of the HPLC fractions provided possible candidate compounds.