Advanced glycation end products (AGEs) generated from glycation can cause inflammation-related diseases such as diabetes and cancer. The bioactive compounds of rosemary extract (RE) were extracted and incubated with sugar-protein rich food and breast cancer cell MCF-7 to investigate its inhibitory effect on glycation and cancer cell proliferation, respectively. The diabetic rat was dosed with RE to investigate its effect on blood glucose, serum malondialdehyde (MDA), cholesterol (CHO), triglycerides (TG), low-density lipoproteins (LDLs), anti-oxidation capacity (T-AOC), superoxide dismutase (SOD) activity, anti-oxidation capacity alkaline phosphatase (ALP), glutamate pyruvate transaminase (GPT), and glutamate oxaloacetate transaminase (GOT). The results show that RE contained seven major phenolics ranging from 17.82 mg/g for rosemarinic acid to 0.01 mg/g for ferulic acid on dry weight basis. It significantly lowered AGEs, carboxymethyl lysine (CML), and protein glycation in a sugar-protein rich intermediate-moisture-food (IMF) model. Furthermore, the survival rates of MCF-7 cells decreased to 6.02 and 2.16% after 96 h of incubation with 1.0 and 2.0 mg/mL of RE, respectively. The blood glucose, MDA, CHO, TG, and LDLs in diabetic rats of RE treatment were decreased. The RE treatment also enhanced the T-AOC and SOD activity. Furthermore, the RE treatment improved liver function through improving ALP, GPT, and GOT activities in diabetic rats. The results provide important information for the nutriaceutical and pharmaceutical application of rosemary extract.

This study investigated the influences of geographical origin, harvest season, and plucking position on the chemical composition and flavor characteristics of Hainan Dayezhong black tea. Systematic analysis of basic components, volatile profiles and metabolomes of tea samples collected under different pre-harvest conditions revealed significant variations in polyphenols, flavonoids and catechins, as well as distinct differences in volatile composition. Key aroma-active compounds identified were nerolidol, linalool, benzaldehyde, benzeneacetaldehyde and methyl salicylate, which were determined to be decisive for the characteristic aroma profile of Dayezhong black tea. Untargeted metabolomics further demonstrated that these factors do not merely alter individual metabolite levels, but also reprogram energy metabolism, carbon–nitrogen allocation, and secondary metabolic pathways, resulting in distinct metabolic signatures among samples. From a systematic chemical perspective, this study elucidates the metabolic basis of Hainan Dayezhong black tea quality formation and establishes a scientific foundation for targeted quality optimization through regulation of key components.