*4.4. Cell Treatments*

Lichen extracts were dissolved in DMSO and PBS (1 mg/mL) as stock. Serial dilutions were then made with PBS. SH-SY5Y cells were pretreated with different concentrations of methanol lichen extracts for 24 h, before H2O2 (250 μM, 1 h). Final DMSO concentration was lower than 0.1% at the highest concentration.
