Empagliflozin is a sodium–glucose co-transporter inhibitor approved for the treatment of type 2 diabetes mellitus. The aim of this study was the 6-month effect of empagliflozin on serum and liver lipidome in C57BL/6J mice fed on a fast food diet (FFD). Three groups were studied; two of them fed on FFD, one with empagliflozin (EMPA group), and another without empagliflozin (FFD group); the third group fed on a chow diet and served as the control group (CD group). Following untargeted lipidomic analysis, the FFD and EMPA groups displayed largely similar serum lipid profiles, characterized by elevated levels in the majority of identified lipids, compared with the CD group, particularly glycerophospholipids. For instance, phosphatidylcholine (PC) 34:1 and phosphatidylinositol (PI) 38:3 increased in the FFD compared with the CD group (both p < 0.001, fold change 2.4 and 17.6, respectively) with comparable increases observed in the EMPA group. Hepatic lipid profiles varied more significantly between groups. For example, PC 34:1 was increased in the FFD and in the EMPA compared with the CD group (both p < 0.001, fold change 1.7 and 1.6, respectively), whereas PC 32:0 was decreased in the FFD group and in the EMPA group compared with the CD group (both p < 0.001, fold change 0.6 and 0.5, respectively). FFD appears to have a more substantial impact on lipidomic profiles compared with the preventive empagliflozin effect. Notably, the concentration of lysophosphatidylcholine (LPC) 22:6 was significantly reduced in the EMPA compared with the FFD group (p < 0.001, fold change 1.4). Interestingly, several glycerophospholipids, including PC 34:1, PC 35:1, PC 36:3, PC 38:4, PI 34:2 and PI 38:3, increased in both serum and hepatic tissues of the FFD and EMPA groups compared with the CD group. In conclusion, limited differences in the lipidomic profile were observed in the EMPA compared with the FFD group (e.g., LPC 22:6). However, both the EMPA and FFD groups showed distinct lipidomic profiles compared with the CD group.

Rats play a crucial role in advancing scientific research and contributing to the understanding of various diseases. The striking structural similarity between the rat foot and the intricate anatomy of the human hand has drawn scientific interest to these animals. However, detailed morphometric and functional analyses of the adult Sprague–Dawley rat foot, including its dimensions, range of motion, and grip strength, remain limited in the literature. We aimed to examine the hind feet of 42 adult male Sprague–Dawley rats, each weighing 300–350 g. Using a multifaceted approach, we inspected hind paw morphology and performed descriptive statistical analyses of foot dimensions (a), measured unilateral hind foot grasping strength (b), assessed joint mobility (c), and examined the microscopic appearance of the hind foot third digit (d). One animal was additionally used to observe the hind limb skeletal architecture using microcomputed tomography. This study provides critical normative data regarding the structure and function of the hind foot in adult Sprague–Dawley rats, thereby facilitating future studies on musculoskeletal diseases.