Investigation of the antioxidant effect of flaxseed oil in chick embryos with experimental cataract model

Cataract, one of the most common causes of visual impairment and blindness in the world, is a vision problem characterized by increased opacity of the lens. There are studies reporting that the use of corticosteroids is one of the factors in the formation of cataracts. Although surgery is preferred in its treatment, there are studies on the use of antioxidants among alternative treatment methods. Flaxseed oil (FO), which is a good source of alpha linolenic acid (ALA) and linoleic acid (LA), shows antioxidant properties thanks to the lignans in its structure. Antioxidants are important agents that have protective roles against pathological processes mediated by oxidative stress in the body. Considering these data in the literature, we aimed to investigate the antioxidant effect of FO in the corticosteroid-induced chick embryo cataract model in our study. Within the scope of the study, 125 specific pathogen free (SPF) fertilized eggs were used. Eggs; The control group, HC group, low (0.1 ml HC and 50 µL/egg FO), medium (0.1 ml HC and 100 µL/egg FO) and high dose (0.1 ml HC and 150 µL/egg FO) FO groups were given. It was divided into 5 groups. Expressed FO and HC doses were injected into the chorioallantoic membrane with insulin injectors on the 15th day of the study. On day 17, all chick embryos were removed from the eggs and bulbus oculi of the embryos were dissected using a dissecting microscope. Cataract formation in the lenses of 9 embryos in each group was evaluated, and biochemical analyzes of glutathione (GSH), malondialdehyde (MDA), total antioxidant level (TAS), total oxidant level (TOS), caspase 3 and caspase 9 levels were measured in the lenses of 8 embryos. In the bulbus oculi of 7 embryos, the rate of apoptotic cells that were histologically stained positively by TUNNEL staining method was determined. All of the lenses in the control group were transparent and no cataracts were observed. Six of the lenses in the HC group exhibited grade 4 cataracts and the mean cataract grade was calculated as 3.3. Cataract grades were significantly lower in the FO applied groups compared to the HC group (p<0.05). The mean cataract grades in the HC+FO groups were calculated as 2.9, 2.4, and 1.7 from low to high dose, respectively. Decreased GSH and TAS levels in lenses due to HC application increased in groups treated with FO. MDA, TOS, caspase 3 and caspase 9 levels of other biochemical parameters decreased depending on the dose of FO. In addition, apoptotic cell count was performed with the TUNEL method and a statistically significant difference was found between the groups when the HC group was compared with the control group (p<0.05). The rate of apoptotic cells decreased statistically significantly (p<0.05), inversely proportional to the applied FO dose rate. As a result; according to our results supported by biochemical and histological findings for HC-induced cataract and oxidative damage, we determined that FO exerts a significant antioxidant effect depending on the dose.