Doxorubicin (DOX) is used as an anticancer drug despite its many side effects. Thymoquinone (THQ) is a plant-derived substance that exhibits antioxidant and anti-inflammatory properties. We investigated the protective effects of THQ on DOX induced nephrotoxicity in rats. Rats were divided into five groups of eight: group 1, untreated control; group 2, olive oil group given olive oil intraperitoneally (i.p.) for 14 days; group 3, THQ group given 10 mg/kg THQ i.p. for 14 days; group 4, DOX group given a single dose of 15 mg/kg DOX i.p. on day 7 of experiment; group 5, DOX + THQ given 10 mg/kg THQ i.p. for 14 days and 15 mg/kg DOX i.p. on day 7. Kidney tissues were evaluated for histopathology. Caspase-3, IL-17, GRP78 and TNF-α immunostaining was used to determine the expression levels of these proteins among the groups. The TUNEL method was used to determine the apoptotic index. Total antioxidant status (TAS), total oxidant status (TOS), and TNF-α and TGF-β1 levels in kidney tissue were measured using ELISA assay. Histopathologic damage, caspase-3, IL-17, GRP78 and TNF-α immunoreactivity, TUNEL positive cells, TOS, TNF-α and TGF-β1 levels were increased in group 4 compared to group 1. The TAS of group 4 decreased compared to group 1. We found decreased caspase-3, IL-17, GRP78 and TNF-α expressions and TUNEL positive cells in group 5 compared to group 4. In rats given DOX, THQ reduced kidney damage by suppressing endoplasmic reticulum stress, inflammation and apoptosis pathways.
Keywords: Adriamycin; apoptosis; doxorubicin; endoplasmic reticulum stress; inflammation; kidney; nephropathy; rats; thymoquinone.