IC50: 2.5 μM ( Leishmania infantum )
Protein tyrosine phosphatases (PTPases)
Phosphatase of regenerating liver (PRL)

Pentamidine (0-10 µg/mL; 6 days; WM9, DU145, C4-2, Hey, WM480, and A549 cells) treatment inhibits the growth of cancer cells in a concentration-dependent manner.
The cytotoxic properties of Pentamidine isethionate towards the promastigotes of the protozoan parasite Leishmania infantum is determined. The leishmanicidal activity of Pentamidine isethionate is 60 times higher after 72 h of incubation than that of Cisplatin. Pentamidine isethionate induces a higher amount of programmed cell death (PCD) than Cisplatin, which is associated with inhibition of DNA synthesis and cell-cycle arrest in the G2/M phase. Binding of Pentamidine isethionate to calf-thymus DNA (CT-DNA) induces conformational changes in the DNA double helix, consistent with a B-->A transition. The interaction of Pentamidine isethionate with ubiquitin leads to a 6% increase in the beta-sheet content of the protein.

Pentamidine (0.25 mg/mouse; intramuscular injection; every 2 days; for 4 weeks; athymic nude mice) treatment markedly inhibits the growth of WM9 human melanoma tumors in nude mice.