Anti-proliferative effect of Moringa oleifera Lam (Moringaceae) leaf extract on human colon cancer HCT116 cell line

Purpose: To investigate the in vitro anti-proliferative effect and mechanism of action of Moringa oleifera Lam. leaf extract on human colon carcinoma HCT116 cell line.Methods: M. oleifera leaves were extracted with methanol. It was fractionated by Sephadex LH-20 column chromatography. Several fractions were identified by thin layer chromatography (TLC), proton nuclear magnetic resonance (1H NMR) and mass spectrometry (MS). The growth inhibitory activity and mechanism of action of the extracts in HCT116 colon cancer cells were investigated by 3-(4, 5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide (MTT) assay and Western blotting.Results: Successive fractions from M. oleifera leaf crude extracts by column  chromatography were combined into four pooled batches (MOL1 - MOL4) according to their absorbance at 260 nm and TLC pattern. MOL2 and MOL3 contain astragalin and isoquercetin, respectively. The results from MTT assay indicated that cell proliferation was significantly (p < 0.05) inhibited in a concentration-dependent fashion, especially by MOL2, MOL3 and MOL4. MOL2 and MOL3 exhibited a stronger cell growth  inhibition than their major ingredients. The anti-proliferative activity of MOL2 - MOL4 in HCT116 colon cancer cells was  mediated by downregulation of ERK1/2 phosphorylation.Conclusion: M. oleifera leaf extract has a strong anti-proliferative activity which is exerted by decreasing ERK1/2 phosphorylation. Thus, the extract has a potential for use in cancer chemoprevention.Keywords: Moringa oleifera, Anti-proliferation, Colon cancer, AKT, ERK1/2 phosphorylation, Chemopreventio