Induction of neuronal differentiation in neurosphere stem cells by ellagic acid derivatives

A bioassay-guided fractionation of methanol extracts of stem barks, combined with screening based on Epidermal Growth Factor (EGF)-responsive neural stem cells (erNSCs) differentiation assay, has been used. This study resulted in the isolation of 3,3'-di-O-methylellagic acid 1, 3,3'-di-O-methyl ellagic acid-4-O-beta-D-xylopyranoside 2, ellagic acid 3, and arjunolic acid 4. Among them, compounds 1 and 2 exhibit potent induction of neuronal differentiation in neurosphere stem cells with no cytotoxic effect. These results indicate that compounds 1 and 2 may be useful as pharmacological agents for the treatment of neurodegenerative diseases. These compounds may account, for the use of T. superba in folk medicine for nervous system and mental disorders.