Usnic Acid Exerts Antiproliferative and Apoptotic Effects by Suppressing NF-κB p50 in DU145 Cells.

Objective: Nuclear factor kappa B (NF-κB) is one pathway that controls the expression of genes involved in many cancer events such as proliferation, apoptosis, metastasis, and invasion. Usnic acid is a molecule with many biological effects such as being anticholinergic, gastroprotective, anti-inflammatory, anti-cancerous, and especially antioxidant. This study aims to mechanistically examine the apoptotic behaviors of usnic acid in DU145 prostate cancer cells and the molecules it acts on in the NF-κB pathway. Materials and Methods: This study investigates the apoptotic changes in DU145 cells after usnic acid administration through JC-1 staining and caspase-3 activity measurements. In addition, it tests the effects of usnic acid on subunit p50 and p65 protein and gene expressions in the NF-κB pathway through the respective Western blot and qPCR measurements. Results: The IC50 values of usnic acid at 24 and 48 h in DU145 cells were calculated as 167.06±12.35 μM and 42.15±3.76 μM, respectively. In addition, JC-1 staining showed usnic acid-treated DU145 cells to trigger apoptosis by increasing the membrane permeability of their mitochondria. NF-κB p50 protein expression was also found to be suppressed after usnic acid administration. Conclusion: The results of this study show usnic acid administration to suppress proliferation and to induce mitochondrial apoptosis by suppressing the NF-κB pathway in DU145 cells. This effect of usnic acid indicates it to be combinable with chemotherapeutic agents and evaluable as an alternative in cancer treatment. [ABSTRACT FROM AUTHOR]