Characterization of a Synthetic Steroid 24-keto-cholest-5-en-3β, 19-diol as a Neuroprotectant.
BACKGROUND
Neuroactive steroids represent promising candidates for the treatment of neurological disorders. Our previous studies identified an endogenous steroid cholestane-3β, 5α, 6β-triol (Triol) as a novel neuroprotectant.


AIM
We aimed to identify a potent candidate for stroke treatment through a screening of Triol analogs.


METHODS
Hypoxia- and glutamate-induced neuronal injury models in vitro, middle cerebral artery occlusion (MCAO)-induced cerebral ischemia model in vivo, fluorescein diacetate (FDA) for alive and propidium iodide (PI) for dead staining, LDH assay, and calcium imaging techniques were used.


RESULTS
24-keto-cholest-5-en-3β, 19-diol (Diol) showed the most potent neuroprotective effect among the screened structurally related compounds. FDA and PI staining showed that Diol concentration dependently increased the survival rate of cerebellar granule neurons (CGNs) challenged with glutamate or hypoxia, with an effective threshold concentration of 2.5 μM. Consistently, the quantitative LDH release assay showed the same concentration-dependent protection in both models. Diol, at 10 μM, potently decreased glutamate- and hypoxia-induced LDH release from 51.6 to 18.2% and 62.1 to 21.7%, respectively, which values are close to the normal LDH release (~16-18%). Moreover, we found Diol effectively decreased MCAO-induced infarction volume in mice from ~23% to 7%, at a dose of 6 mg/kg. We further explored the underlying mechanism and found that Diol attenuated NMDA-induced intracellular calcium ([Ca(2+) ]i ) increase in cortical neurons, suggesting a negative modulatory effect on NMDA receptor.


CONCLUSION
Taken together, we identified Diol as a potent neuroprotectant. It may represent a novel and promising neuroprotectant for stroke intervention.
['Yan|Min|M|', 'Liu|Ai-Ling|AL|', 'Zhou|Shu-Jia|SJ|', 'Tang|Li-Peng|LP|', 'Ou|Yan-Qiu|YQ|', 'Yin|Wei|W|', 'Chen|Xin-Ying|XY|', 'Su|Xing-Wen|XW|', 'Qiu|Peng-Xin|PX|', 'Huang|Yi-Jun|YJ|', 'Zhang|Jing-Xia|JX|', 'Yan|Guang-Mei|GM|', 'Leng|Tian-Dong|TD|']
D000818:Animals D000831:Animals, Newborn D002118:Calcium D015687:Cell Hypoxia D002478:Cells, Cultured D002531:Cerebellum D002777:Cholestanols D004195:Disease Models, Animal D018690:Excitatory Amino Acid Agonists D018698:Glutamic Acid D020244:Infarction, Middle Cerebral Artery D007770:L-Lactate Dehydrogenase D016202:N-Methylaspartate D009474:Neurons D018696:Neuroprotective Agents D010100:Oxygen D051381:Rats D017207:Rats, Sprague-Dawley
Steroid Neuroprotection Stroke NMDA