Investigation of the potential use of a Gloriosa superba L. extract for the treatment of cancer

Gloriosa superba L. (Liliaceae) is traditionally used in Ayurveda for several purposes, such as the treatment of gout, snake bites, intestinal worms, etc. G. superba contains colchicine, which has antimitotic properties and it has been used in the treatment of cancer. However, because of the low therapeutic index, it is not used as an anticancer drug anymore. G. superba contains not only colchicine but also other, very similar alkaloids. In this project the G. superba extract is evaluated for its potential use in the treatment of cancer. The hypothesis is that a combination of various active compounds in an extract may have more beneficial effects than the pure compounds, due to synergism and the presence of prodrugs such as glycosides. The 80% ethanolic extract of the G. superba seeds was phytochemically investigated and colchicine, 3-O-demethylcolchicine and colchicoside were isolated and identified by means of HPLC-SPE-NMR. In order to prepare a quantified extract with a known amount of colchicine derivatives for future in vivo experiments, an analytical HPLC-method was developed and validated. The 80% ethanolic extract contained 1.3% of colchicoside, 1.3% of 3-O-demethylcolchicine and 2.9% of colchicine. The cytotoxicity of the 80% ethanolic extract was also determined on three different human cancer cell lines and a high cytotoxic effect was observed on the tested cell lines with an IC₅₀ value of 0.340 ± 0.015 µg/mL (MDA-MB-231 WT), 0.167 µg/mL (PANC-1) and 0.167 ± 0.008 µg/mL (HT-29) using the sulforhodamine B assay.

Fig. 1: HPLC chromatogram of the 80% ethanolic extract of the G. superba seeds.