5α,6β-Dihydroxycholestanol is an oxysterol metabolite of cholesterol formed from conversion of cholesterol epoxides by 5,6-epoxysterol hydrolase. It inhibits NMDA-mediated calcium influx in HEK293 cells expressing NR1/NR2B NMDA receptors in a concentration-dependent manner. It also binds to voltage-gated sodium (Nav) channels and decreases action potentials in hippocampal neurons in vitro when used at a concentration of 10 uM. It increases survival of spinal cord motoneurons, cortical neurons, and cerebellar granule neurons in vitro when used at concentrations ranging from 5 to 15 uM. 5α,6β-Dihydroxycholestanol is neuroprotective in a rat model of cerebral ischemia when administered at a dose of 12 mg/kg and increases latency to seizure onset and reduces severity of seizures induced by pentylenetetrazole in rats. 5α,6β-Dihydroxycholestanol has been used as a replacement for cholesterol in the study of cholesterol binding proteins.
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