A novel compound β-sitosterol-3-O-β-D-glucoside isolated from Azadirachta indica effectively induces apoptosis in leukemic cells by targeting G0/G1 populations

Azadirachta indica, popularly known as ‘Neem’, is a very important plant in the Ayurveda system of medicine. It is known toprevent about 40 types of diseases in home-practice. A previous report showed that the methanolic extract of this plant can effectively control the proliferation of leukemia cells. Therefore, this research focuses on searching for a new molecule with potent anti-leukemic property. Ethanolic extract was prepared from the dried leaves. Four bio-molecules were isolated viz. rutin, isoquercetin, quercetrin and β-sitosterol-3-O-β-D-glucoside from the ethanolic extract by repeated column chromatography and HPLC. Quercetrin structures of the isolated molecules were confirmed by Mass, 1HNMR, 13C NMR spectra analysis. MTT assay revealed that β-sitosterol-3-O-β-D-glucosideeffectively reduced the proliferation of MOLT 4 leukemic cells in a dose and time dependent manner. DAPI staining with confocal microscopy indicated that β-sitosterol-3-O-β-D-glucoside efficiently induced nuclear DNA fragmentation in MOLT 4 cells. Finally, flow cytometry after PI staining showed that the compound has potential to check the cell cycle progression at sub G1 phase. In summary, we can conclude that β-sitosterol-3-O-β-D-glucoside has potential to be good therapeutic drug in leukemia treatment in future