The Cytotoxic Effects of Moringa oleifera Leaf Extract and Silver Nanoparticles on Human Kasumi-1 Cells

BackgroundMoringa oleifera, commonly known as "moringa", is widely cultivated in tropical and subtropical regions across the globe. Extensive studies have shown that various parts of the moringa tree exhibit anti-cancer properties. This study determined the effects of sequential moringa leaf extracts and silver nanoparticles synthesized from moringa leaf extract on Kasumi-1 leukemia cells. Methods and ResultsDried moringa leaf powder was sequentially extracted with the assistance of ultrasound starting with absolute ethanol, followed by 50% ethanol, and finally, deionized water. The aqueous extract was utilized to synthesize silver nanoparticles. The optimum conditions to generate moringa silver nanoparticles (MO-AgNPs) were eight hours of incubation at 60°C with 1 mM silver nitrate and 1% moringa aqueous extract from sequential extraction. The three extracts and MO-AgNPs were used to treat Kasumi-1 cells for 24, 48, 72 hours with concentrations ranging from 400 to 12.5 µg/mL, while cell viability was determined with 3(4, 5-dimethythiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay. After 72 hours of treatment, the moringa leaf absolute ethanol extract displayed the strongest inhibitory effects on Kasumi-1 cells with IC50 of 10 µg/mL, in comparison to moringa leaf 50% ethanol extract (25 µg/mL) and aqueous extract (>400 µg/mL). Interestingly, MO-AgNPs exhibited the strongest cytotoxic effects on Kasumi-1 cells with an IC50 of 7.5 µg/mL. Cytotoxic study on normal CD34+ cells treated with up to 50ug/mL of either MO-AgNPs or ethanol extract still had more than 80% cell viability indicating that the treatments have selective cytotoxicity against the cancer cells. Morphological studies of Kasumi-1 cells treated with IC50 of moringa leaf ethanolic extract and MO-AgNPs show a lot of shrinking, dying cells and cell debris. Cell cycle studies displayed an increase in cells at the G1 phase for ethanol leaf extract, while MO-AgNPs caused cell cycle arrest at the S phase after treatment with IC50 dose for 24 hours. Moringa leaf ethanol extract and the nanoparticles induced apoptosis in Kasumi-1 cells as shown by annexin V - FITC assays. Gene expression analysis by qPCR verified these outcomes, as the moringa leaf ethanol extract led to significant upregulation of proapoptotic gene caspase 8, whereas the MO-AgNPs caused a significant increase of proapoptotic protein BID. ConclusionThis study reveals that moringa ethanolic leaf extract and MO-AgNPs induced potent