INVESTIGATING THE ROLE OF A MULTI-TARGETED DIETARY SUPPLEMENT ON ATTENUATING RADIATION INDUCED SKELETAL MUSCLE DAMAGE

Abstract

Exposure to ionizing radiation (IR) is known to negatively impact musculoskeletal health. A Multi-Targeted Dietary Supplement (MTDS) has been formulated to protect against radiation-induced cellular damage. This study investigated the efficacy of this MTDS to ameliorate IR’s negative effects on skeletal muscle. Six experimental groups of ten-week-old male BALB/c mice were randomized (n=8/group) to either a control diet (CD) or the MTDS diet (MD). The MTDS was mixed into the CD, and mice were pre-fed the MD for 28 days. Each diet group was randomly divided into control (no irradiation) or an irradiated (IR) group and continued their respective diet until euthanized at day 21 or 28. IR-treated mice received 0.8 Gy fractions (day 0 and 14 or day 0, 7 and 14) for a cumulate dosage of 1.6 or 2.4 Gy, respectively. Tibialis anterior (TA), quadriceps, gastrocnemius and plantaris (GP), and soleus muscles were collected. Body weights remained unchanged at 1.6 Gy, while a reduction was observed at 2.4 Gy in the IR+CD group compared to the IR+MTDS group. The relative TA and GP muscle/body weight ratios were elevated in IR+CD groups, whereas the MD maintained lower muscle/body weight ratios. Cross-sectional area and min Feret values in the IR+CD were larger compared to control and the IR+MD groups demonstrating that the MTDS was protective against radiation-induced edema. Centrally-located nuclei (per mm2) in the IR+CD group were significantly elevated in both the TA and GP compared to control and the IR+MTDS group. Macrophage F4/80 staining showed a significant increase in macrophages within muscle fibers in the IR+CD groups, which was blunted by the MD. These results demonstrate that IR exposure leads to long-term negative changes on skeletal muscle and the MTDS attenuated these effects, positioning it as a potential therapeutic approach to IR exposure. Supported by the Canadian Space Agency.