Protective Effects of Maternal Administration of a Standardized Extract of Cultured <i>Lentinula edodes</i> Mycelia against Radiation-Induced Fetal Morphological Abnormalities

Exposure to ionizing radiation during early pregnancy poses serious risks to fetal development, particularly during organogenesis. In this study, we evaluated the protective effects of AHCC^®, a standardized extract of Lentinula edodes mycelia with known immunomodulatory and metabolic properties, using an ICR mouse model. Intraperitoneal administration of AHCC prior to 1.4-Gy γ-irradiation on gestational day 9 significantly reduced the incidence of tail malformations and diaphragmatic hernias, without affecting implantation or fetal survival. Additionally, lifelong AHCC ingestion across three generations did not alter reproductive parameters, namely, gestation length and litter size, supporting its safety during pregnancy. These findings suggest that AHCC may mitigate radiation-induced teratogenic effects through maternal immune modulation, without compromising reproductive outcomes.