Protocatechuic Acid Ameliorates Cisplatin-Induced Inflammation and Apoptosis in Mouse Proximal Tubular Cells

Cisplatin is a highly cytotoxic drug used for the treatment of head, neck, and soft tissue cancers; however, it has nephrotoxic effects that can lead to acute kidney injury. Protocatechuic acid (PCA) is a natural widely available antioxidant found in many fruits such as kiwi, mango, and berries. We have recently shown that PCA reduced renal injury in a mouse model of unilateral ureteral obstruction. The current study aims to investigate the protective effects of PCA in Cisplatin-induced inflammation in vitro in Boston University Mouse Proximal Tubular (BUMPT) cells. BUMPT cells were cultured in complete DMEM. Confluent BUMPT cells were then treated with 20 μM Cisplatin ± PCA 50 or 100 μM for 24 h. PCA treatment showed a dose-depending increase in % cell viability in Cisplatin-treated BUMPT cells. PCA treatment also dose-dependently decreased Cisplatin-induced increases in oxidative stress (ROS and TBARS), inflammation (p-NF-κB and IL-6), and apoptosis (cleaved caspase-3 and % of TUNEL⁺ cells) compared to Cisplatin-only treatment. The reduction in oxidative stress, inflammation, and apoptosis with PCA treatment in Cisplatin-treated BUMPT cells was associated with decreases in tubular physical barrier resistance and the expression of the tight junction protein zonula occludens-1 (ZO-1) when compared to BUMPT cells treated with Cisplatin alone. The current findings suggest that PCA treatment improves tubular barrier function in Cisplatin-treated BUMPT cells via reductions in oxidative stress, inflammation, and apoptosis.