In Utero Exposure to Gestational Diabetes Altered Distribution of T-Cell Population in Spleen of Rats' Offspring: Potential Ameliorative Role of Thymoquinone.

Gestational diabetes (GD) increases the risk of developing chronic diseases in adulthood. Thymoquinone (TQ) modulates the body's immunity. Investigating the adverse effects of GD on long run in the offspring’s spleen and splenic T-cell population with investigation of the counteracting influence of TQ was the aim of this study. Pregnant rats were allocated into three groups: Control, GD, and GD+TQ groups. Offspring from the pregnant rats were sequestered and named accordingly, then sacrificed at 21(PND21) and 42 (PND42) days postnatally. Spleens were extracted and processed for histological and immunohistochemical assessments. TQ administration significantly decreased fasting blood glucose in the pregnant mothers. The offspring’s spleens of GD-groups at both time points showed significantly decreased number and size of white pulps with apparent red pulp expansion, significant reduction in CD3 and CD4 positivity with significant elevation in CD8 and caspase 3 positivity compared to the corresponding control groups. Meanwhile, TQ preserved the normal splenic construction, significant elevations in the number and size of lymphatic follicles, significant elevation in CD3 and CD4 positivity and significant reduction in CD8 and caspase 3 positivity in GD-TQ-groups at both time points compared to the corresponding GD-groups. In conclusion, GD induced splenic morphological changes; apoptosis, hypocellularity, and alteration in immune-phenotypic proportion of T cells in spleens of offspring at PND 21& PND 42 leading to long-standing splenic changes that may, later, disturb the immune function. Meanwhile, thymoquinone administration to the hyperglycemic pregnant rats reduced these effects and protected the offspring’s spleens and, subsequently, the offspring’s immunity.