Protective Effects of Traditional Herbal Formulas on Cisplatin‐Induced Nephrotoxicity in Renal Epithelial Cells via Antioxidant and Antiapoptotic Properties

Abstract

Acute kidney injury (AKI) is characterized by a rapid loss of renal function. Drug-induced AKI accounts for up to 60% of all cases, resulting in a severe threat particularly to hospitalized patients, but there are no effective treatments. Four polyherbal formulas, Bojungikki-tang (BJ), Palmijihwang-tang (PJ), Oryeong-san (OR), and Wiryeong-tang (WR), have long been used for treatments of symptoms of kidney disease in traditional Korean medicine. Even though they are commercially available, evidences supporting the efficacy on AKI are still lacking. Therefore, the effectiveness of polyherbs on AKI and the underlying mechanisms were examined. Renal cell damage was induced by cisplatin at 20 μM and 16 μM in proximal tubular epithelial cell lines of rat NRK-52E and human HK-2, respectively. The cells were treated with the polyherbal formals for 3 days, and the cell viability, antioxidant activities, and apoptosis were examined. In addition, the proliferative effects were assessed under serum-free conditions. The results were compared with those of the vehicle-treated cells as a control. Three polyherbs BJ, PJ, and WR but not OR showed strong free radical scavenging activities in the 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay. The treatments of BJ, PJ, OR, and WR significantly increased the cell viabilities under cisplatin-induced nephrotoxicity. Consistent with the results of the DPPH assay, superoxide dismutase and catalase activities were increased in the cisplatin-induced cell model treated with BJ, PJ, and WR but not with OR. However, annexin-V-positive cells and cleaved caspase 3 expression were significantly reduced in the cell model treated with all of the polyherbs. Cell proliferation was observed in treatment with all of the polyherbs, which was particularly evident in the OR-treated cells. This provides effective complementary evidences to promote the development of traditional herbal formulas to treat AKI.

Protective Effects of Traditional Polyherbs on Cisplatin-Induced Acute Kidney Injury Cell Model by Inhibiting Oxidative Stress and MAPK Signaling Pathway

“…Similar to other studies [21][22][23], we found that cisplatin showed IC 50 values at 20 µM in NRK and 16 µM in HK-2, and ascorbic acid was the most efficient at 35 µg/mL (250 µM) in both cisplatin-induced cell injury models. The cell models showed increased ROS production and reduced activities of antioxidant enzymes, SOD and catalase, due to responses to the oxidative stress [24].…”

“…Our previous study has shown the nephroprotective effects of four other polyherbs including Bojungikki-tang, Palmijihwang-tang, Oryeong-san, and Wiryeong-tang [23]. The polyherbs are main traditional medicines for treating renal diseases; however, the antioxidant effects were little in treatments with Oryeong-san or lower in treatments with others.…”

“…Apoptotic changes and cell proliferation were measured using flow cytometry, as described previously [23]. Briefly, for apoptosis, cell samples were incubated with a rabbit anti-annexin V-FITC (1:1000, #14085, Abcam, Cambridge, UK) for 30 min, followed by propidium iodide at 50 µg/mL (Life Technologies, Carlsbad, CA, USA) for 10 min.…”