Ouabain (Octahydrate)

Ouabain Octahydrate is an inhibitor of Na⁺/K⁺-ATPase, used for the treatment of congestive heart failure. In Vitro: Ouabain (100 μM) induces NLRP3 inflammasome activation and IL-1β release in macrophages. Ouabain-induced NLRP3 inflammasome activation is mediated through K⁺ efflux^[1]. Ouabain (3 nM) alters the expression of EMT markers in NHK and ADPKD cells, and modifies cell-cell adhesion properties in ADPKD. Moreover, ouabain enhances migration of ADPKD cells, selectively modulates tight junctions, and modulates adherens junctions in ADPKD cells in a selective manner. Ouabain also activates TGFβ-Smad3 signaling, alters TER in ADPKD cells^[2]. Ouabain (25, 50 or 100 nM) treatment significantly reduces cell proliferation and viability in Raji cells in a dose-dependent manner, with IC₅₀ of 76.48±4.03 nM. Ouabain increases the number of apoptotic cells, induces autophagy, and upregulates Beclin-1 in Raji cells^[4]. In Vivo: Ouabain (3 mg/kg) significantly decreases cardiac contractile force with an enlarged LVESD when mice are primed with LPS. IL-1β deficiency attenuates ouabain-induced cardiac dysfunction and injury. IL-1β secreted by infiltrated macrophages contributes to ouabain-induced cardiac inflammation. Deficiency of NLRP3 and Casp1 attenuates ouabain-induced cardiac dysfunction and macrophage infiltration^[1]. Ouabain (30 µg/kg, i.p.) modulates ABCB1 activity in thymocytes of Wistar rats and it has the same effect on Swiss mice at 300 µg/kg. After 14 days of ouabain treatment, the MAP of rats is significantly elevated^[3].