Identification of Esterified Oleanolic Acid in Cestrum Parqui Leaves and its Apoptotic Induction on HT-29 Cell Line

Abstract

In nowadays, there is a continuous and urgent need to discover natural anticancer products because there is an increase in the toxic sides effects associated with current chemotherapeutic agents. For this reason, we evaluated in this study, the antiproliferative effect of 8 fractions obtained from methanolic extract of Cestrum parqui leaves on three different cells lines (HT-29, HL-60, Molt-3 cells). After selection of the most active fractions, a bioactive purified compound noted “S” was isolated by chromatography methods (HPLC-DAD-UV; HPLC-PAD-ELSD and HPLC-UV-preparative). We used HT-29 as model cells to determine the effect of purified compound S on growth cell, induction of apoptosis death and in cell cycle disruption.
The MTT test showed that compound S inhibited the growth of HT-29 cells with an IC50 of 6μg/ml. The analysis of treated- HT-29 cells by flow cytometry after staining of cells with Annexin/FITC and propidium iodide (PI), demonstrated that this compound induces cell cycle arrest in G1 phase and induce apoptotic cell death. The structure of “S” was elucidated base on one and two NMR spectroscopic procedures and mass spectrometry as esterified oleanolic acid ((8E,11E)-tetradeca-8,11-dienoate of oleanolic acid) .
In conclusion, this study is the first investigation that shows that Cestrum parqui contains an esterified oleanolic acid which possesses anticancer activity against HT-29.