Erinacine S from Hericium erinaceus mycelium promotes neuronal regeneration by inducing neurosteroids accumulation.

Erinacines derived from Hericium erinaceus have been shown to possess various health benefits including neuroprotective effect against neurodegenerative diseases, yet the underlying mechanism remains unknown. Here we found that erinacine S enhances neurite outgrowth in a cell autonomous fashion. It promotes post-injury axon regeneration of PNS neurons and enhances regeneration on inhibitory substrates of CNS neurons. Using RNA-seq and bioinformatic analyses, erinacine S was found to cause the accumulation of neurosteroids in neurons. ELISA and neurosteroidogenesis inhibitor assays were performed to validate this effect. This research uncovers a previously unknown effect of erinacine S on raising the level of neurosteroids.