Methodology for Rapid Isolation of Moringin: Potential AnticancerCompound from the Seeds of Moringa stenopetala

The seeds of Moringa stenopetala which are known to be rich sources of glucosinolates, primarily glucomoringin, have been shown to have limited anticancer effects when tested in vitro. In the present study, however, the water extract of the seeds obtained following defatting by hexane displayed potent cytotoxic activity against HepG2 (IC50, 6.28 ± 0.55 μg/ml) and the SH-SY5Y human neuroblastoma (IC50, 9.81 ± 1.30 μg/ml) cells. The methanol extract displayed a weak cytotoxic activity against the HepG2 human hepatocellular cancer cells when tested upto 500 μg/ml, while extraction with hexane yielded the non-cytotoxic fixed oil which fatty acid composition was primarily oleic acid (75%). By monitoring the constituents of the water extract by HPLC and a one-step combiflash chromatographic system using C-18 silica gel system, the principal active constituent (glucomoringin isothiocyanate or moringin; 4(α-L-rhamnosyloxy)-benzyl isothiocyanate) was isolated. Moringin was 6.3 and 2.4 times more potent than etoposide in the HepG2 and SH-Sy5Y cell lines respectively. The isolation of this potent potential anticancer compound from the seeds of M. stenopetala without the need for multi-step chromatographic and enzyme-digestionbased purification steps are discussed.