Antimutagenic and antioxidant activity of the essential oils of Citrus sinensis and Citrus latifolia.

The essential oils of Citrus sinensis and Citrus latifolia showed antimycotic activity against Candida spp. isolated from the oral cavity; they are neither mutagenic on the Ames test nor cytotoxic. Their main components are R-(+)-limonene, β-thujene, α-myrcene and γ-terpinene. The aim of this work was to evaluate their antimutagenic and antioxidant capacities. Antimutagenic properties were evaluated against MNNG and ENNG on S. typhimurium TA100; against 2AA on strain TA98 and in front of 4NQO and NOR on strain TA102. Both were antimutagenic against MNNG (p < 0.001) but only C. latifolia was antimutagenic against ENNG (p < 0.001). Both presented antimutagenic activity against 2AA (p < 0.001). They were antioxidant against the ROS-generating compound 4NQO (p < 0.001) and the antibiotic NOR (p < 0.001). In the antioxidant evaluation, the activity in DPPH assay was in a range of 6-23% for C. sinensis and of 22-71% for C. latifolia. Both were antioxidant compared with BHT in β-carotene bleaching assay and were able to decreased apoptosis in HaCat cells stimulated with H2O2. The levels of intracellular superoxide ion were lower in the presence of both oils. In conclusion, the essential oils of C. sinensis and C. latifolia are antimutagenic against at least three types of mutagens and have antioxidants properties.