Regulatory effects of hawthorn polyphenols on hyperglycemic, inflammatory, insulin resistance responses, and alleviation of aortic injury in type 2 diabetic rats

[Display omitted] •HPE regulates insulin resistance in skeletal muscle and liver.•HPE regulates the SIRT1/AMPK/NF-κB pathway reducing inflammation in the liver.•HPE activated aortic SIRT1 to regulate NF-κB and Wnt2/β-catenin reducing injury.•Hawthorn polyphenols and metformin exert similar inhibitory effects on T2D in rats.•The type and number of VOCs in the colon of diabetic rats differed from other rats. Hawthorn polyphenol extract (HPE) is beneficial for patients with type 2 diabetes (T2D). However, the mechanism underlying its beneficial effects remains unclear. We investigated the inhibitory effects and mechanisms of HPE on insulin resistance, inflammation, and aortic injury in T2D rats, using metformin (MF) as a positive control. High-performance liquid chromatography-electrospray ionization-tandem mass spectrometry (HPLC-ESI-MS/MS) was used to determine the primary polyphenols in HPE. Hematoxylin & Eosin (H&E) staining was used to evaluate pathological conditions of the skeletal muscle, liver, and aorta vessels in each group. The levels of serum and intestinal tissue oxidative stress, tumor necrosis factor α (TNF-α), and inflammatory interleukin-6 (IL-6) were also assessed. Western blotting was used to evaluate protein expression levels in the associated molecular pathway. Volatile organic compounds (VOCs) from colon contents were determined using headspace-gas chromatography-ion mobility chromatography. Our results showed that supplementation with 300 mg HPE/kg body weight over four weeks significantly improved total cholesterol (TC), total triglyceride (TG), insulin, and lipopolysaccharide (LPS) levels in diabetic rats (p