Teratogenic Effects of Thallium and Protective Role of the Aqueous Extract of Annona muricata in the Fetuses of Pregnant Mice

Background: Humans are exposed to thallium sulfate (TO), a toxic heavy metal, through contaminated drinking water, food, or air. Medicinal plants with antioxidant properties such as Annona muricata (soursop) can be used as a natural solution to the problems caused by TI exposure.
Objectives: This study aims to determine the preventive effects of A. muricata on the toxic effects of TO in pregnant mothers and their fetuses.
Methods: Pregnant females were divided into 3 experimental groups. The first group received distilled water and served as the control group. The second group was given an aqueous solution of custard apple leaves and, after 4 hours, drinking water containing TO. The third group was given drinking water containing only thallium sulfate. Pregnant mice in the second and third groups received experimental materials from the first day of pregnancy to the 15th and 18th days of pregnancy. Blood samples were taken from pregnant mice on the two days (D15, 18). Histological preparations were performed on the placenta to observe the changes in the second and third groups. During the two days of the investigation, the fetuses’ phenotypic alterations were also examined. 
Results: The results showed the effect of TO + A. muricata on placental tissue (cystic of glycogen cells, increment in thickness of trophoblast septa with deposition of fibrin, dilation of maternal sinusoid, and vacuolated degeneration. Also, there were morphologic changes in fetuses, such as hemorrhage with permanence of the severity effects of TO in the brain, hemorrhage and spinal bifida, atrophy of the rhombencephalon, open eyelids, septo-optic dysplasia, abnormalities of the fetal extremities, hump body, hematoma. Finally, the majority of the results for the second group were similar to the rates of the control group. 
Conclusion: The graviola apple plant’s leaves can be used at the stated amounts to counteract the effects of TO in drinking water.