Effects of Fennel Essential Oil on Cisplatin‑induced Nephrotoxicity in Ovariectomized Rats

Background: Cisplatin (cis‑diamminedichloroplatinum II (CDDP)) is an effective drug in cancer therapy to treat solid tumors. However, the drug is accompanied by nephrotoxicity. Previous reports indicated that estrogen has no protective role against CDDP‑induced nephrotoxicity, but the role of phytoestrogen as an estrogenic agent in plants is not determined yet. The major composition of fennel essential oil (FEO) is trans‑anethole that has estrogenic activity; so, we used FEO as a phytoestrogen source against CDDP‑induced nephrotoxicity. Materials and Methods: Fifty‑four ovariectomized Wistar rats were divided into seven groups. Groups 1-3 received different doses of FEO (250, 500, and 1000 mg/kg/day, respectively) for 10 days. Group 4 received saline for 10 days plus single dose of CDDP (7 mg/kg, intraperitoneally (ip)) at day 3. Groups 5-7 received FEO similar to groups 1-3, respectively; plus a single dose of CDDP (7 mg/kg, ip) on day 3. On day 10, the animals were sacrificed for histopathological studies. Results: The serum levels of blood urea nitrogen (BUN) and creatinine (Cr), kidney tissue damage score (KTDS), and kidney weight (KW) and body weight changes in CDDP‑treated groups increased significantly (P < 0.05). FEO did not reduce the levels of BUN and Cr, KTDS, and KW and body weight changes. Also, the serum and tissue levels of nitrite were not altered significantly by FEO. Conclusion: FEO, as a source of phytoestrogen, did not induce kidney damage. In addition, FEO similar to estrogen was not a nephroprotectant agent against CDDP‑induced nephrotoxicity.