Introduction:  Tartrazine is a broadly used food additive. It can induce several adverse effects on different body organs. Omega-3 fatty acids have a documented antioxidant, anti-apoptotic and anti-inflammatory effects. Aim of the work: To study the induced histological changes by tartrazine in the parotid gland and to investigate the protective action of omega-3-fatty acids against these changes.Material and Methods: Twenty-one adult male albino rats were divided into 3 groups; Group I (control group), Group II (tartrazine-treated group) received tartrazine daily at a dose of 320 mg/kg body weight orally and Group III (tartrazine and omega-3 treated group) received omega-3 daily at a dose of 300 mg/kg body weight orally in addition to tartrazine in the same dose in group II. The treatment continued for four weeks. Parotid gland specimens were processed for light microscopic examination using Hematoxylin and Eosin, Sirius red stains and caspase-3 immunostaining in addition to electron microscopic examination. Results: Parotid acini in tartrazine-treated group showed a histological deterioration in the form of darkly stained nuclei and cytoplasmic vacuolations. Statistically, area % of both collagen fibers staining and caspase-3 immunostaining increased significantly in comparison to the control group. Ultrastructurally, irregular nuclei, electron-lucent granules dominance and dilated rough endoplasmic reticulum were detected in the acinar cells of tartrazine-treated group in addition to degenerative changes in ductal epithelium. Treatment with omega-3 improved the structure of the parotid gland as detected by both histological and morphometric studies.
Conclusion Omega-3 treatment ameliorated the structural effects of tartrazine on the parotid gland.