Inhibition of benzo[a]pyrene- and cyclophoshamide-induced mutagenicity by Cinnamomum cassia

Cinnamomum cassia is used as a flavoring spice with some established medici nal properties. In this study, we evaluated the antimutagenic effect of C. cassia against two mutagens, viz. benzo[a]pyrene (B[a]P) and cyclophosphami de (CP). The antimutagenic properties of C cassia were examined by the Ames test. In vivo chromosomal aberration (CA) and micronuclei tests were also employed to assess the antimutagenic effect of C. cassia in mice after pret reatment with the extract orally for seven consecutive days. To elucidate t he mechanism by which C. cassia exerts its antimutagenic effect, certain ke y enzymes involved in bioactivation and detoxification processes were also investigated. Changes in liver cytochrome P450 (Cyt P450), glutathione cont ent (GSH), glutathione S-transferase (GST), glutathione reductase (GR), and glutathione peroxidase (GPX) were evaluated in pretreated animals. It was observed in the Ames test, bone marrow chromosomal aberration assay, and mi cronucleus test that C cassia exerted significant antimutagenic effects aga inst B[a]P and CP in animals treated with the plant extract. C cassia pretr eatment decreased Cyt P450 content but increased GSH content and the activi ty of glutathione-de pendent antioxidant enzymes, viz. GST, GR, and GPX. Th e present findings demonstrate that the antimutagenic potential of C. cassi a could be attributed to its modulatory effect on the xenobiotic bioactivat ion and detoxification processes. (C) 2001 Elsevier Science B.V. All rights reserved.