17 Amna Rashid Rameen Matloob Khalid Rauf Muhammad Hassham Hassan Bin Asad Zia Uddin Nabi Shah Ikram Ullah Khan Muhammad Ikram Journal of Animal and Plant Sciences JAPS 20272027 37 1 1018-7081 https://doi.org/10.36899/JAPS.2027.1.0013 <p style="text-align: justify;">Ionizing radiation causes significant harm to lymphoid organs through oxidative stress, cellular depletion, and disruption of tissue architecture. The study aimed to establish a sublethal&nbsp;¹³⁷Cs &gamma;-radiation-induced model of thymic and splenic injury and to evaluate the mitigating effects of rosmarinic Acid (RA). Total 144 BALB/c mice, 6-8 weeks age and 18-22 g weight, were randomly allocated into six groups: normal control, irradiated control, RA50, RA100, RA150, and levamisole. Mice were exposed to&nbsp;¹³⁷Cs &gamma;-radiation to induce thymic and splenic injury and were subsequently treated with RA at doses of 50, 100, 150 mg/kg for 14 days. The mitigating effects of RA were assessed using hematological parameters, thymic and splenic indices, organ cellularity, histological architecture, oxidative-stress and antioxidant markers, and the thymic expression of FoxN1, IL-6, IL-7, and IL-15. At 150 mg/kg dose, thymus and spleen index increased significantly (p &le; 0.001) from irradiated group. Histological examination showed reduced radiation-associated hypocellularity and architectural disruption in the thymus and spleen, improvement observed at 150 mg/kg. RA significantly reduced malondialdehyde levels in the thymus and spleen (p &le; 0.001) than irradiated group following treatment with 150mg/kg and significantly improved SOD (p &le; 0.001), GPx (p &le; 0.001), CAT (p &le; 0.01) activity. Furthermore, RA significantly modulated the radiation-altered expression of IL-7 (p &le; 0.001), IL-6, IL-15, and FoxN1 (p &le; 0.01) mRNA in the thymus, at 150 mg/kg. Overall, RA, mitigated sublethal radiation-associated thymic and splenic injury, as demonstrated by improvements in hematological and organ indices, oxidative-stress and antioxidant markers, lymphoid tissue architecture, and thymic mRNA expression. These findings suggest that RA may have potential as a natural immunomodulatory agent against radiation-associated lymphoid injury.</p> Thymus, Radiation, Rosmarinic acid, Cytokines, Antioxidant Pakistan Agricultural Scientists Forum https://thejaps.org.pk/AbstractView.aspx?mid=2026-JAPS-648