Gestational Exposure to Silymarin Increases Susceptibility of BALB/c Mice Fetuses to Apoptosis.

BACKGROUND: Silymarin is a flavonolignan that has been the subject of research to evaluate the beneficial properties for decades. Silymarin has been known for its potent cytoprotective, hepatoprotective and antioxidant activities. The goal of the present study was to gain a deeper understanding of possible molecular mechanisms of apoptosis of the injuries induced by silymarin on BALB/c mice fetuses.

METHODS: The present experimental study was carried out in virgin female BALB/c mice. The animals were divided randomly into 4 groups. Three test groups were injected intraperitoneally with silymarin at doses of 50, 100 and 200 mg/kg/day during gestational days 6-15. The control group received the solvent by the same route at equivalent volume. Western blot analysis was conducted to determine the levels of caspase-3 and caspase-8 in fetal heart, kidney, lungs and brain tissue.

RESULTS: The results of this study showed that silymarin administration during organogenesis at doses of 50, 100 and 200 mg/kg can significantly increase the protein levels of caspase-3 and 8 in heart, kidneys and brain tissues of mice fetuses compared with control group (p<0.001). Silymarin exposure could not change the level of apoptotic markers in fetal lung tissue.

CONCLUSION: According to the results, programmed cell death, especially via the intrinsic pathway, plays a pivotal role in the pathogenesis of silymarin-induced malformations in some tissue including heart, kidneys and brain. More studies are needed to determine other molecular mechanisms underlying silymarin- induced embryo toxicity.