FIG. 4.

Demethylcurcumin pretreatment is sufficient and an order of magnitude more potent than C₉₅ curcumin on a concentration basis to protect HT4 neuronal cells against glutamate challenge. HT4 cells were seeded in six-well plates (0.1 × 10⁶/well). Demethylcurcumin (DC) or C₉₅ was added to the cells (at the indicated concentrations) for 8 h and then washed before glutamate exposure. “p” indicates that cells were pretreated at the dose shown and removed before glutamate challenge. Results are expressed as mean ± SD, p < 0.05; ^*compared with glutamate treated.