Rumex crispus Phytochemicals: Chemopreventative Potential for Human Colon Carcinoma

Abstract

The study and isolation of naturally occurring phytochemicals has produced several chemotherapeutic drugs and derivatives still in use today including: paclitaxel (taxol), etoposides (podophyllotoxin), and irinotecan. The objective of this study was to isolate novel chemotherapeutic compounds of Rumex crispus (R. crispus) using high performance liquid chromatography (HPLC), characterize with mass spectrometry (MS), and test with in vitro assays.Human colon adenocarcinoma cells (DLD‐1ATCC® CCL‐221™) were used to test the effectiveness of R. crispus phytochemicals as chemotherapeutics. Accelerated solvent extraction (ASE) was utilized to extract 0.1% TritonX‐100 soluble phytochemicals from R. crispus obtained in East Texas. Extracts from both rhizomes and leaves were screened for chemotherapeutic activity using CellTiter 96® Non‐Radioactive Cell Proliferation Assay (Promega, Corp.) and the Apo‐ONE® Homogeneous Caspase‐3/7 Assay (Promega, Corp.). To further explore the relative types of phytochemicals responsible for cytotoxicity and apoptosis in the cells, reverse phase HPLC and MS was utilized. Phytochemical fractions collected from HPLC were titrated with NaOH, to neutralize the H3PO4 present from HPLC. Each HPLC fraction was tested for levels of cytoxicity using the CellTiter 96® Non‐Radioactive Cell Proliferation Assay (Promega, Corp.). Those fractions with positive killing were then subjected to MS to identify specific phytochemicals present.Cytotoxic effects were observed in both rhizome and leaf extracts of R. cripsus, as well as the induction of apoptosis with increasing dosage of R. crispus extracts. Large amounts of benzylphytosterol or benzylisoquinalone type molecules were present in the MS data of ASE R.crispus root extracts.