Figure 4.

Neuroprotective effects of LM compounds on MPP⁺-treated BE(2)-M17 cells. Retinoic acid-differentiated BE(2)-M17 cells were treated with LM-016, LM-021, or LM-036 (10 μM) and MPP⁺ (0.62 mM) on day 5. On day 7, (A) tyrosine hydroxylase (TH, green) expression, (B) caspase-1, caspase-3 and caspase-6 activities, as well as (C) neurite length, process and branch were measured (n = 3). Shown were TUBB3-stained images and images of cells outlined with multi-colored mask to assign each outgrowth to a cell body for neurite outgrowth quantification. Processes and branches in LM-036-treated cells were marked with red and white arrows, respectively. To normalize, TH expression and caspase activities in MPP⁺-untreated cells were set at 100%. p-values: comparisons between MPP⁺-untreated and treated cells (^#p < 0.05, ^##p < 0.01), or with and without compound addition (*p < 0.05, **p < 0.01, ***p < 0.001).