Efficacy of crocin and safranal as protective agents against genotoxic stress induced by gamma radiation, urethane and procarbazine in mice
Crocin (CRO) and safranal (SAF) are bioactive constituents of saffron (dried stigma of Crocus sativus flower), an expensive spice with medicinal properties. Aqueous extract of saffron is known for its antigenotoxic effect against environmental genotoxins/carcinogens. However, there is need to identify saffron constituents responsible for this antigenotoxic effect. The aim of our investigation was to ascertain the role of CRO and SAF as inhibitors of in vivo genotoxic stress. For this purpose, Swiss albino mice were pretreated with CRO (50-mg/kg body weight (bw))/SAF (0.025- and 0.25-ml/kg bw) by gavage for 2 days. Thereafter, the pretreated mice were exposed to the genotoxic agents: (1) gamma radiation (GR; 2 Gy), (2) urethane (URE; 800 mg/kg) and (3) procarbazine (PCB; 60 mg/kg). In addition, CRO (50 mg/kg) was co-administered with the nitrosation reaction mixture of methylurea (MU; 300-mg/kg bw) + sodium nitrite (15 mg/kg) which can form N-nitroso-N-MU in the stomach. Genotoxic damage was measured by performing the bone marrow micronucleus test. Results obtained demonstrated significant reductions in the incidence of micronucleated polychromatic erythrocytes in the bone marrow of mice pretreated with CRO/SAF before exposure to the above DNA damaging agents, GR, URE and PCB. Co-administration of CRO with the nitrosation reaction mixture led to significant decrease in genotoxicity when compared to nitrosation reaction mixture alone. Histopathological studies revealed that these saffron constituents reduced testicular cell damage induced by the test genotoxins. The cell-free DNA-nicking assay using pBR322 DNA showed significant protective effects of CRO against hydroxyl radical-induced strand breaks.