Use of micronucleus and comet assay to evaluate evaluate the genotoxicity of oregano essential oil (Origanum vulgare l. Virens) in rats orally exposed for 90 days.

Abstract

Essential oils from Origanum spp. exhibit antioxidant and antimicrobial activities making them suitable for use as food additives. The incorporation of oregano essential oil in active food packaging is under study; however, it has been not authorized for this purpose thus far. In order to fulfill the requirements of the European Food Safety Authority (EFSA), the aim of the present study was to determine the genotoxic potential of oregano essential oil using both the micronucleus (MN) test and comet (standard and enzyme-modified) assays in Wistar rats treated with 50, 100, or 200 mg/kg body weight administered daily for 90 days. MN was performed in cells from the bone marrow and standard and enzyme-modified comet assays were conducted in stomach, liver and blood cells. The major compound detected in the analytical study of oregano essential oil from Origanum vulgare L. virens, was carvacrol (55.82%) followed by thymol (5.14%), as well as their precursors, γ-terpinene (16.39%), and ρ-cimne (4.71%). The results obtained in the genotoxicity assays indicated lack of effect in MN and standard comet assay under the conditions tested. Furthermore, no apparent oxidative damage was observed in the enzyme-modified comet assay in any of the tissues examined of rats exposed to oregano essential oil for 90 days. Therefore, this oregano essential oil appears to be safe in Wistar rats and might be considered as a potential active material in food packaging industry.

Oregano Phytocomplex Induces Programmed Cell Death in Melanoma Lines via Mitochondria and DNA Damage

“…For this purpose, the Ames test, recommended by the European Food Safety Authority (EFSA) as a proper assay to assess food safety [ 87 ], was carried out. It provided the proof that HCOE did not have a non-mutagenic effect [ 88 , 89 ], as expected. Indeed, O. vulgare and its derivatives, which are accepted as food ingredients by the U.S. Food and Drug Administration, are listed among the GRAS (Generally Recognized As Safe) substances by the Code of Federal Regulations of the USA and are generally well tolerated by the human body, although gastrointestinal upset and skin allergic reactions have been associated to them [ 90 ].…”

Dietary Supplementation with the Red Seaweed Porphyra umbilicalis Protects against DNA Damage and Pre-Malignant Dysplastic Skin Lesions in HPV-Transgenic Mice

“…The use of both assays allows the gathering of complementary information, as DNA damage detected by the comet assay occurs earlier, is rather short-lived, and does not require cell division to become evident. On the contrary, the MN test detects DNA-strand breaks that are not repaired and persist beyond mitosis, giving rise to clastogenic lesions or to aneuploidy [39,40,41]. P. umbilicalis reduced non-specific GDI in HPV16-transgenic mice.…”

In Vivo Genotoxicity Evaluation of a Stilbene Extract Prior to Its Use as a Natural Additive: A Combination of the Micronucleus Test and the Comet Assay

“…Heparinized blood samples were mixed v/v (1/1) with phosphate buffered saline (PBS) solution and the lymphocytes were isolated with Histopaque® (SigmaAldrich, Madrid, Spain) and centrifuged (400 g , 30 min) [ 33 ]. Finally, the cells were washed twice with PBS and re-suspended at a concentration of 2 × 10 5 cells/mL.…”

“…The recommendations of OECD guideline 489 [ 26 ] were followed to perform the standard comet assay. Cells suspension was mixed with 0.5% low-melting point agarose for blood samples [ 33 ], while for stomach and liver cells were mixed with 1% low-melting point agarose and both samples were placed on a microscope slide [ 28 , 33 ]. Then, the standard and modified comet assays were performed as previously described by Mellado-García et al [ 28 ].…”