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. Author manuscript; available in PMC: 2017 Dec 14.
Published in final edited form as: Toxicol Sci. 2014 Jul 30;142(1):33–44. doi: 10.1093/toxsci/kfu154

FIG. 7.

FIG. 7

Usnic acid activates JNK and JNK activation is involved in apoptosis. (A) Total cellular proteins were extracted at 6 and 24 h after exposure to usnic acid. The expression levels of activated JNK (phospho-JNK), p38 (phospho-p38), and ERK1/2 (phospho-ERK1/2) were detected by Western blot analyses. The same blot was stripped and used to determine the amount of each kinase. GAPDH was loaded as internal control. Data are typical of three experiments. (B and C) HepG2 cells were pretreated with 10&M SP600125 (JNK inhibitor) for 2 h prior to 24 h treatment with indicated concentrations of usnic acid. Apoptosis was assessed by caspase-3/7 activity (B). Cell viability was determined by MTT assay (C). The bar graphs show the mean ± SD of three experiments. **p < 0.005, and ***p < 0.001 versus treatment with usnic acid alone.