Figure 3

Luteolin inhibits glutamate-induced cytotoxicity in HT-22 cells. HT-22 cells were pre-treated with luteolin at different concentrations (5–50 µM) for 24 h and quercetin 10 µM was used as a positive control. Subsequently, the cells were exposed to 5 mM glutamate for 18 h. Bar graphs show (A) the % cell viability (n = 5) and (B) the % LDH release (n = 3). (C) The intracellular ROS was visualized under the CellInsight CX7 High-Content Screening (HCS) platform, the bottom bar graph shows the relative intracellular ROS level (n = 3). (D, left) The HT-22 cells were stained with PE-Annexin V/7-AAD probes, the numbers of cell deaths were analyzed via flow cytometry Q1: necrosis, Q2: late apoptosis, Q3: live, Q4: early apoptosis (n = 3). (D, right) The histogram represents the percentages of necrotic and apoptotic cells. The data were collected from at least three independent experiments and the results were shown in mean \(\pm\) SEM. *p-value < 0.05, **p-value < 0.01, ****p-value < 0.001 compared with glutamate-treated group, ^#p-value < 0.05, ^####p-value < 0.001 compared with untreated control group. L:luteolin, Q:quercetin.