Curcumin Affects the Proliferation and Neurogenesis of Embryonic Neural Stem Cells in Rats

Background: Curcumin, found in the rhizome of Curcuma longa, demonstrates anti-inflammatory and neuroprotective properties. Objectives: This study aims to assess its effects on the proliferation and differentiation of embryonic neural stem cells (NSCs). Methods: Female rats (n = 36) became pregnant, resulting in the formation of embryos (n = 176). Neural stem cells from female embryos (n = 50, embryonic day 15.5, E15.5) were cultured in a serum-free medium with growth factors (FGF-2 and EGF). Curcumin was then added at doses of 0.1, 0.5, and 1 µM. The proliferation of NSCs was assessed using the MTT colorimetric assay, nestin immunofluorescence labeling, and RT-PCR. NSC differentiation was compared using immunocytochemistry (ICC) and RT-PCR for nestin, glial fibrillary acidic protein (GFAP), and class III β-tubulin (Tuj-1). Results: Curcumin at concentrations of 0.1 and 0.5 µM increased the proliferation of NSCs, as indicated by an increase in neurosphere diameter. Similarly, the MTT assay showed that curcumin at doses of 0.1 and 0.5 µM enhanced the viability of NSCs. In the differentiation condition, no significant difference was observed. However, RT-PCR analysis showed that nestin and GFAP expressions reached their highest levels in cells treated with curcumin at a dose of 0.5 µM, while Tuj-1 expression significantly increased in cells treated with curcumin at a dose of 1 µM. Conclusions: Curcumin at lower doses may regulate the proliferation and differentiation of NSCs. Treating NSCs with curcumin could provide a promising option for pre-differentiation before cell therapy.