Role of Gibberellic and Indole Acetic Acid in Altering Ocular Structure and Function of Mother Rats and their Offspring

Abstract

Recently, plant growth hormones have been widely used in green houses and the consumptions of agriculture food products have markedly increased; however their toxicological aspects are still unclear. The aim of the present study is to illustrate the toxicities of plant growth hormones; gibberellic (GA3) and indole acetic acid (IAA) on ocular tissues of pregnant Wistar albino rats and their offsprings. Intra-gastric administration of either GA3 or IAA (100 mg/kg body weight) to mother rats were carried out for one month prior to conception as well as throughout gestation period (n=20). The control received saline-free organochemical compounds (n=10). At parturition, mother rats and their offsprings were sacrificed by light anesthesia, and their ocular regions were separated and investigated for light and transmission electron microscopy, immunochemical staining of Caspase-3, Bcl-2 and p53 and assessments of antioxidant enzymes and DNA fragmentation. Maternal administration of either GA3 or IAA was found to develop cataractous lenses to about 6% (3/20) in GA3-treatment and 4% (2/20) in IAA-treatment. The applied organochemical compounds developed retinopathy in mother rats and their offsprings. These were characterized by apparent damage of ganglion and nuclear cells. In mothers, the photoreceptor’s outer segment showed spotty dissolution of their stacked membranes while in offsprings, there was still lack of differentiation. The retinal tissue showed discrete positive immunostaining foci with P53, Pcl2 and caspase-3, especially in ganglion and nuclear cells compared with control. The antioxidant enzymes' catalase (CAT), superoxide dismutase (SOD), glutathione reductase (GR) and peroxidase (GPx) showed apparent depletion and vice versa for malondialdhyde (MDA) and hydrogen peroxide (H2O2), the markers of cell death. DNA fragmentation was markedly detected.  Finally, it was concluded that maternal administration of GA3 and IAA led to the development of retinopathy and development of cataractous lenses parallel to the increase of immunostaining of caspase-3, Pcl2 and P53 and decrease of the endogenous antioxidant system and increase of DNA damage.