Abstract Purpose: This study aimed to evaluate the neuroprotective ability of the conditioned medium of stem cells from human exfoliated deciduous teeth (CM-SHED) to prevent glutamate induced apoptosis of neural progenitors. Materials and methods: Neural progenitors were isolated from two-day-old rat brains, and the conditioned medium was obtained from a mesenchymal stem cell SHED. Four groups were exam ined: neural progenitor cells cultured in neurobasal medium with (N + ) and without (N-) gluta mate and glycine, and neural progenitor cells cultured in CM-SHED with (K + ) and without (K-) glutamate and glycine. Results: The expression of GABA A1 receptor (GABAAR1) messenger RNA (mRNA) in neural progenitor measured by real-time quantitative PCR. GABA contents were measured by enzyme linked immunosorbent assay, whereas the apoptosis markers caspase-3 and 7-aminoactinomycin D were analysed with a Muse cell analyzer. The viability of neural progenitor cells in the K + group (78.05 %) was higher than the control group N- (73.22 %) and lower in the N+group (68.90 %) than in the control group. The K + group showed the highest GABA con tent, which significantly differed from that in the other groups, whereas the lowest content was observed in the N + group. The expression level of GABAAR1 mRNA in the K + group was the highest compared to that in the other groups. CM-SHED potently protected the neural progen itors from apoptosis. Conclusions: CM-SHED may effectively prevent glutamate-induced apoptosis of neural progenitors.