This article reports the genotoxicity assessment of an extract of M. oleifera seed powder and the water-soluble Moringa oleifera lectin (WSMoL) isolated from seeds. The lectin isolated by chitin chromatography showed hemagglutinating activity with different erythrocytes, activity in a broad pH range (4.5 to 9.5), and retention of hemagglutinating activity after being heated to 100 °C. Genotoxicity of the seed extract and WSMoL were assessed using the cell-free plasmid DNA as well as the Salmonella typhimurium (Ames and Kado) assays with TA97, TA98, TA100, and TA102 in the presence or absence of hepatic metabolization. Seed extract at concentration (0.2 μg/μL) recommended to treat water was not genotoxic by Ames, Kado, and cell-free plasmid DNA assays. S. typhimurium strains showed to be sensitive to M. oleifera extract revealing a mutagenic effect at doses higher than 0.6 μg/μL with hepatic metabolization. The extract at doses higher than 0.4 μg/μL, without hepatic metabolization, was mutagenic for TA100 and TA102. WSMoL was nonmutagenic by used assays. The use of high concentrations of the extract may pose a risk to human health and the safe use of M. oleifera seed powder to treat water for human consumption requires more study; however, the purified lectin could be an alternative for water treatment.
Practical application: The concentration 0.2 μg/μL of M. oleifera seed extract recommended to treat water for humans did not pose a risk to human health. The mutagenicity detected at concentrations higher than 0.4 μg/μL was not due to WSMoL, lectin isolated from extract.