Neuroprotective Compounds from the Embryo of Nelumbo nucifera Seeds

Objectives: The present study was designed for the purpose of evaluating the neuroprotective activity of compounds isolated from the embryo of N. nucifera seeds on glutamate‑induced cell death in HT‑22 cells. Materials and Methods: We isolated compound from the embryo of N. nucifera using various chromatograms and confirmed chemical structure by various spectroscopy. The neuroprotective effects of the compounds against glutamate‑induced cell death in HT‑22 cells were investigated using an (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Results: We isolated 6 compounds, 1,2,3,4‑tetrahydro‑7,8‑isoquinolinediol (1), 1,2,3,4‑tetrahydro‑1‑[(4‑hydroxyphenyl) methyl]‑2‑methyl‑6,7‑Isoquinoline diol (2), 1,2,3,4‑tetrahydro‑1‑[(4‑hydroxyphenyl) methyl]‑2‑methyl ‑7‑Isoquinolinol(3),1‑(3,4,5‑trihydroxyphenyl)‑ethanone(4), 1‑(2,3,5,6‑tetrahydroxyphenyl)‑ethanone(5),3‑(prop‑1‑enyl) benzene‑1,2,4,5‑tetrol (6) from the embryo of N. nucifera. Among these compounds, 1,2,3,4‑tetrahydro‑7,8‑isoquinolinediol and 1,2,3,4‑tetrahydro‑1‑[(4‑hydroxyphenyl)methyl]‑2‑methyl‑6,7‑Isoquino linediol significantly decreased glutamate‑induced cell death in HT‑22 cells. In addition, these compounds exacerbated the reactive oxygen species level and intracellular Ca2+ accumulation. Conclusion: The neuroprotective efficacy of 1,2,3,4‑tetrahydro‑7,8‑isoquinolinediol and 1,2,3,4‑tetrahydro‑1‑[(4‑hydroxyphenyl) methyl]‑2‑methyl‑6,7‑Isoquinolinediolmay be related to their antioxidative effect.