Gentamicin leads to kidney failure by producing free radicals and inflammation in renal tissue. Cineole as a terpenoid has antioxidant properties. Antioxidants can play an effective role in preserving the oxidant-antioxidant balance. Hence, this study investigated the effects of cineole on acute kidney injury (AKI) and renal function recovery following gentamicin administration in rats.

36 male Wistar rats were randomly divided into 6 equal groups; healthy control, gentamicin, DMSO carriers, cineole 50, cineole 100, and vitamin E. After 12 days of treatment, the animals were anesthetized with ketamine and xylazine. Serum and kidney samples were taken for biochemical and gene expression experiments.

Cineole 50 and 100 groups increased the levels of serum glutathione (GSH) (<0.05), kidney and serum glutathione peroxidase (GPX) (<0.001), kidney catalase (CAT) (<0.001), serum nitric oxide (NO) (<0.001), and the GPX gene (<0.05) compared with the gentamicin group. These treatment groups had decreased levels of kidney malondialdehyde (MDA) (<0.001), serum creatinine (<0.001), urine protein, and the Interleukin 6 (IL-6) gene (<0.05) compared with the gentamicin group. Cineole 50 increased the serum MDA (<0.001), urea, and CAT gene (>0.05) and decreased the kidney GSH (<0.05) and the tumor necrosis factor-alpha (TNF-α) gene (<0.05). Cineole 100 increased the kidney GSH (<0.05) and decreased the serum MDA (<0.001), urea, CAT gene (>0.05), and TNF-α gene (>0.05) compared with the gentamicin group. Improvement in histological alterations was displayed in cineole groups compared with the gentamicin group.

Cineole can reduce kidney damage caused by nephrotoxicity following gentamicin consumption through its antioxidant and anti-inflammatory properties.