LAUSR

ABSTRACT Cyclophosphamide (Cy), a chemotherapeutic agent, is of great interest in the clinic due to its relatively high oncotoxic specificity. However, its usage is restricted due to its severe side effects, particularly hepatotoxicity. This study investigates the potential cytoprotective effect of Nigella sativa oil against the high toxic dose of Cy. 40 albino rats were randomly divided into 4 groups: control group, Cy group that received a single intraperitoneal dose of Cy (200 mg/kg), and Cy-treated groups with 50 and 200 mg/kg of Nigella sativa oil (NSO), for 15 days. Enzyme activities were investigated by monitoring levels of superoxide dismutase (SOD) and catalase (CA) in serum. Liver function was monitored by measuring levels of alkaline phosphatase, glutamate pyruvate transaminase, glutamic oxaloacetic transaminase, and glutathione. DNA damage and hepatocytes viability were determined by the comet and MTT assays. The marked depression in the antioxidants defense system may be the major mechanism of Cy-induced hepatocytes damage. NSO not only protects hepatocytes from the severe toxicity of Cy through enhancement of antioxidant enzymes activities, but also provides a DNA protection. The knowledge gained in this study might be of significant clinical importance for a large number of cancer patients.