Abstract: Objective: To comprehensively evaluate the hypoglycemic and antioxidant effects of Camellia nitidissima flower. Methods: The chemical constituents in the aqueous extract of C. nitidissima flower (CFA) were identified by high performance liquid chromatography-mass spectrometry (HPLC-MS). Next, a mouse model of type 2 diabetes was established, and the diabetic mice were randomly divided into five groups: model, positive control (acarbose at 20 mg/kg mb), low-, medium- and high-dose CFA (200, 400 and 800 mg/kg mb, respectively). After five weeks of intragastric intervention, general growth characteristics, serum glucose, fasting insulin (FINS) and lipid levels, oxidative stress in pancreas and liver tissues, tissue morphological changes and cell apoptosis were analyzed. Results: CFA had a high content of polyphenols and polysaccharides. The half-maximal inhibitory concentration (IC50) values for scavenging of 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical and α-glucosidase inhibition were (24.14 ± 0.64) and (69.99 ± 1.97) μg/mL, respectively. Seven compounds were identified from CFA. In addition, CFA could effectively improve the ‘three more and one less’ symptoms of diabetic mice, significantly reduce the levels of fasting blood glucose (FBG), postprandial blood glucose (PBG), total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C) and malondialdehyde (MDA), increase the levels of insulin and high-density lipoprotein cholesterol (HDL-C), improve the activities of total superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), and alleviate pathological damage in pancreas and liver tissues. Conclusion: CFA has significant hypoglycemic and antioxidant effects on type 2 diabetic mice.

Key words: Camellia nitidissima flower; type 2 diabetes; glucose and lipid metabolism; oxidative stress