Biological activities of the essential oil from the Moro orange peel (Citrus sinensis (L.) Osbeck)

Citrus essential oils have become the focus of several researches, because they have broad biological activity, due to their chemical composition. However, there are few studies covering Moro orange essential oil. Thus, the aim of this study was to evaluate the effects of fresh Moro orange peel essential oil on antifungal, antioxidant, cytotoxic, and genotoxic activities in normal and tumor cells. The essential oil was extracted by hydrodistillation and characterized by GC/MS and GC/FID. Cytotoxicity was evaluated by MTS assay in normal cells (CCD-1059Sk) and tumor cells (CCD-1059Sk), and the genotoxicity was determined in normal cells by the comet assay. Antifungal activity was evaluated by the disk diffusion test against Aspergillus carbonarius and Aspergillus flavus filamentous fungi. The antioxidant activity was determined in DPPH, ABTS, and beta-carotene assay. The essential oil was mainly composed of monoterpenes such as limonene (95.12%), alpha-pinene (0.35%), sabinene (0.54%), and myrcene (1.07%). The essential oil did not cause cell death after 48 hours of treatment in normal cells, but the cell viability of tumor cells decreased by 50% in the presence of the essential oil at a concentration of 272.6 mu g/mL. Although no antioxidant effect was observed, the growth of all evaluated fungi was inhibited with a minimum inhibitory concentration (MIC) of 125 mu L/mL. The essential oil from the Moro orange is promising for cancer treatment, and it can be used as a natural preservative in food systems.