Malus floribunda Siebold ex Van Houtte Fruit Extract Mitigates Fructose/Streptozotocin Induced Type 2 Diabetes in Rats

We aimed to investigate the potential antidiabetic effects of an ethanol extract derived from the fruit of Malus floribunda (MF) on insulin resistance, oxidative stress, inflammation, and apoptosis associated with diabetes. In our study, diabetes was induced through the administration of a 10% fructose solution and 40 mg/kg Streptozotocin (STZ). Once diabetes had been induced, metformin (Met) 300 mg/kg and the MF extract (250 mg/kg and 500 mg/kg) were administered orally once daily for 30 days. At the end of the experiment, markers of insulin resistance, oxidative stress, inflammation and apoptosis were evaluated in the serum, muscle and liver tissues of the different groups. The MF extract significantly improved the levels of HOMA-IR, insulin receptor (InR), insulin receptor substrate 1 (IRS-1) and glucose transporter 4 (GLUT4)—key components of peripheral insulin resistance associated with type 2 diabetes. Fructose/streptozotocin induced oxidative stress, inflammation, and apoptosis were mitigated by increasing Nuclear factor erythroid 2-related factor 2 (NRF2) expression, which restored antioxidant levels (Superoxide dismutase (SOD) and Glutathione (GSH)), significantly improved cytokine levels (Tumor necrosis factor alpha (TNF-α) and Interleukin-1 beta (IL-1β)), and downregulated apoptotic proteins (caspase-3 and caspase-9). We demonstrated the antidiabetic effect of MF extract using a fructose/streptozotocin-induced type 2 diabetes model. MF extract shows promise for future use in herbal medicine. © 2026 by the authors.