A method of treating CD33+ acute and chronic myeloid leukemia in animals including humans, using fraction nos. 1 and 9 obtained from water:methanol fraction by column chromatography, with ratio of water and methanol ranging between 1:5 to 5:1, wherein said water:methanol fraction is obtained from the polar extract of Piper betel by HPLC, with retention time of 3.6 and 24.0 minutes respectively, with said fractions used both individually, and in combination.