Ovarian toxicity of plant-derived edible oils: a 28 days hormonal and histopathological study in Wistar rat

Abstract

Initial evidence on the endocrine-disrupting effects of genetically modified (GM) food motivated us to evaluate the reproductive toxicity of GM and non-GM plant-derived edible oils in female Wistar rats. Sunflower (non-GM), maize (GM), and canola (GM) oils as popular resource dietary oils were purchased from the local market. After tracking the target sequence of CaMV 35S and Nos terminator in all selected batch numbers of edible oils by real-time PCR, oil samples were daily gavaged to 10 weeks Wistar rats for 28 days. Clinical factors, serum lipid levels, sex hormones, and gonadotropins as well as the histopathological changes were compared among groups by statistical analysis. Besides normal lipid profile, gonadotropin levels, and LH/FSH ratio at day 28, serum estradiol levels were raised in both GM (canola oil (p=0.04)) and non-GM (sunflower oil (p=0.008)) groups. In necropsy studies, ovarian atrophies were detected in canola (p<0.001) and sunflower groups (p<0.043) although uterine remained unchanged in all groups. In histopathological evaluations, all sections showed severe congestion and multiple follicular cysts in the sunflower oil group. Simple and secondary cysts in the maize group were the other type of ovarian toxicity in this short period of time. Remarkable estrogenic properties of GM and non-GM plant-derived edible oils with signs of ovarian atrophy, congestion, and cysts may contribute to phthalate or other xenoestrogenic contaminations; therefore, analytical studies of samples and further human populations studies are highly recommended.