<div><p>Swainsonine is a <i>Metarhizium</i> secondary metabolite known differentially for its specific mannosidase inhibitory, toxic and therapeutic activities. Here, the standard and purified swainsonine from <i>Metarhizium anisopliae</i> fermentation broth were comparatively evaluated for their <i>in situ</i> antileukaemic activities in human promyelocytic cell line, HL-60. Both the standard (IC<sub>50</sub> = 6.96 μM) and purified (IC<sub>50</sub> = 9.50 μM) compounds inhibited the leukaemic cell proliferation without inflicting cell membrane disruption at 48 h of post-treatment incubation. The DNA cell cycle analysis showed approximately 48.81% and 60.72% of the treated cells arrested in the synthetic phase (S-phase) at 36 and 48 h, respectively, upon treatment with IC<sub>50</sub> concentration of the purified swainsonine. However, only 29.62% of cells were arrested in S-phase with standard swainsonine at 48 h, suggesting the comprehensive action of certain other metabolites sharing the similar paradigm of antiproliferative properties in <i>Metarhizium</i> broth extract.</p></div
