Objective: 

Cyclophosphamide (CP) is a widely used antineoplastic drug that causes toxicity in the normal cell due to its metabolites. The major drawback of this drug is an undesirable myelosuppression. The possible protective effects of Carvacrol (Car) against CP-related toxicity of blood cells and bone marrow of rats were investigated in this study.

Methods: 

Male Sprague Dawley were divided into ten groups. The groups that had CP treatment alone were killed 3 days after the CP injection. For the groups having CP+Car, Car (5 or 10 mg/kg i.p) administration was started 3 days earlier than the CP administration and continued to the end of the experiment (6 days). On day 4, the animals were weighed again, relative doses of CP were estimated, and CP+Car were administered together. A vehicle-treated control group was also included. On day 7, blood samples were collected and bone marrows of animals were resected under anesthesia.

Results: 

Intraperitoneal (i.p) administration of 50, 100, or 150 mg/kg of CP caused, in a dose-dependent manner, reductions in the number of leukocytes, thrombocytes, and bone marrow–nucleated cells. Car protects the animals from the toxic effect of CP. The best recovery was obtained when 5 mg/kg of Car was given in combination with 50 mg/kg of CP.

Conclusions: 

CP is toxic to bone marrow, leukocytes, and platelets. However, the toxicity depends on the dose of the drug. Our findings suggest that at the appropriate concentration, Car could be a potentially effective drug in the treatment of CP-induced damage and could be used in the prevention and treatment of CP toxicity.