The Effect of Thymoquinone on Hematopoietic Functions in Myelosuppression Induced Rats by Cyclophosphamide

Cyclophosphamide (CP) is an antineoplastic chemotherapeutic. However, because of its excessive toxic side effects, its area of use has become limited, therefore causing several steps of treatment to be negatively affected. Myelosuppression is the main problem with patients who are being treated with CP. Thymoquinone (TQ) is a phytochemical that has long been used in traditional and complementary medicine. Its therapeutic effects have been studied thoroughly and its antioxidant effects have been proven. In this study, it was aimed to evaluate the preventative effects of TQ against myelosuppression seen in rats that are getting CP treatment. In the study, 8-10 weeks old 32 male Sprague Dawley rats with a mean weight of 230-250 gr were used. Four groups were formed with an equal number of rats in each one (n=8). The control group, the TQ group (10 mg/kg TQ), the CP group (50 mg/kg CP), and the TQ+CP group (50 mg/kg CP and 10 mg/kg TQ) were the groups formed. TQ was given to the rats daily by intragastric gavage while CP was given by intraperitoneal injection once a week and 4 times in total. At the end of 28 days of practice, the rats were sacrificed under anesthesia by drawing blood from their hearts. The preventative effects of TQ against myelosuppression induced by CP in rats were determined by measuring the following parameters: hematologic parameters (WBC, Neu, Lym, Mono, Eos, Baso, RBC, HGB, HCT, MCV, MCH, MCHC, RDW, PLT), bone marrow histopathology, hematopoietic growth factors (EPO, TPO and G‒CSF), and oxidant-antioxidant system parameters (MDA, GSH). When the results of data analysis were studied, it was determined that the addition of TQ prevents the following effects of CP: increase in body weight and decrease in numbers of thrombocyte and leukocyte from hematologic parameters, decrease in levels of thrombopoietin and G-CSF from hematopoietic cytokines, decrease in levels of GSH from oxidative stress parameters. In addition, it was found in histopathologic examinations that CP causes damage in stromal and hematopoietic areas and causes increase in adipocyte density, and the addition of TQ prevents these effects. As a result, it was proven by both hematology and histopathology that TQ can, in fact, decrease the level of myelosuppression caused by CP, partially by preserving the levels of some hematopoietic cytokines, and partially by having an antioxidant effect. It was decided that more comprehensive and advanced studies were needed to reveal the positive effects of TQ on bone marrow more clearly.