oleandrin

Oleandrin is a toxic cardiac glycoside derived from the leaves of the *Nerium oleander* plant. Structurally similar to digoxin, it exerts its primary pharmacological effect by inhibiting the membrane enzyme Na+, K+-ATPase, disrupting ion gradients essential for cellular function[1][5][7]. This inhibition leads to increased intracellular calcium in cardiomyocytes, affecting muscle contraction and potentially causing arrhythmias[7]. Oleandrin has been used in traditional medicine for various indications such as cardiac insufficiency, hemorrhoids, ulcers, leprosy, and as an abortifacient; however, it is highly toxic and not approved for medical use due to its narrow therapeutic index and risk of fatal poisoning[1][3][4][5]. In preclinical studies, oleandrin has demonstrated cytotoxic effects against several cancer cell lines through multiple mechanisms including induction of apoptosis (via Fas gene expression), suppression of NF-κB activity, generation of reactive oxygen species leading to mitochondrial injury, inhibition of interleukin-8-mediated tumorigenesis, autophagy induction in tumor cells, caspase activation (notably caspase-3), P-glycoprotein inhibition (chemosensitization), radiosensitization via increased death receptor expression (DR4/5), downregulation of PI3K/Akt/mTOR pathways and improved export of fibroblast growth factor-2[1][6][8]. Despite these findings in vitro and animal models suggesting potential anticancer properties or neuroprotective effects[1], there is no clinical evidence supporting safe or effective use in humans. Oleandrin remains primarily a subject of research interest rather than an approved pharmaceutical agent.