Epothilone D is a natural polyketide compound isolated from the myxobacterium Sorangium cellulosum that binds to tubulin and inhibits microtubule disassembly, thereby blocking mitosis, cellular proliferation, and cell motility, Epothilone D is extensively utilized in cancer research to study microtubule dynamics, mitotic arrest, and cytoskeleton-targeted anticancer mechanisms.

Epothilone D is a more potent microtubule stabilizer in vitro than epothilone A or B. In vitro, Epothilone D has shown potent cytotoxicity in a panel of human tumor cell lines, with similar potency to paclitaxel. Epothilone D also shows a definite advantage over paclitaxel in drug-resistant cell lines and retained its cytotoxicity against a multidrug-resistant cell line over-expressing P-glycoprotein [1].

In a transgenic mouse model of Tauopathy (PS19 mice), which mimics features of Alzheimer's disease, intraperitoneal (i.p.) administration of Epothilone D (1 mg/kg or 3 mg/kg, weekly for 3 months) affected microtubule density and axonal integrity. These structural changes were associated with improvements in cognitive measures in the treated mice. At these dosages, the mice did not exhibit weight loss or neutropenia, indicating a tolerance profile distinct from higher chemotherapeutic doses [2].

Groups of mice (n=3) receive intraperitoneal (i.p.) injections of 3.7 mg/kg of Epothilone D (epoD) dissolved in 100% DMSO, followed by euthanization using approved at times ranging from 0.25 h to 24 h. In another study, groups of mice (n=3) receive injections of 3 mg/kg of epoD in 100% DMSO followed by euthanization 4, 6 and 10 days later. The Epothilone D (epoD) levels in the brain and blood samples are determined using LC-MS/MS protocols. Groups (n=10-13) of 3-month old PS19 tau Tg mice or 3-month old non-Tg littermates are administered weekly i.p. injections of 1 mg/kg epoD, 3 mg/kg of Epothilone D (epoD) or vehicle (DMSO), for a total of 3 months. Animals are monitored for signs of abnormal behavior or distress and are weighed weekly. After final dosing, the mice undergo motor function and cognitive testing. After euthanization, brains and optic nerve (ON) are recovered for immunohistochemical analyses. A subset of mice from each group also undergo necropsy evaluation with organ weights recorded [2].

DMSO: 80 mg/mL (163.36 mM), Sonication is recommended.

10% DMSO+40% PEG300+5% Tween-80+45% Saline: 3.3 mg/mL (6.74 mM), Sonication is recommended.