Biochemical Enrichment of Rosemary Kombucha and Its Protective Effects Against High-Fat-Diet-Induced Metabolic Dysfunction in Mice
TL;DR
Fermentation enhanced the phytochemical richness of rosemary, and RK exerted protective metabolic effects by suppressing lipid synthesis and promoting fatty acid oxidation, support RK as a promising functional beverage for mitigating diet induced metabolic dysfunction.
Abstract
This study investigated the biochemical transformation of rosemary during kombucha fermentation and evaluated the metabolic effects of rosemary kombucha (RK) in a high fat diet (HFD) mouse model. Fermentation markedly acidified the beverage and significantly increased titratable acidity, total phenolic content, and total flavonoid content. HPLC analysis revealed substantial increases in key bioactive compounds—including rosmarinic acid, caffeic acid, luteolin 7 O glucoside, and carnosol—and the emergence of carnosic acid, while oxidation sensitive ursolic acid declined. In vivo, HFD feeding induced obesity, while RK supplementation significantly attenuated weight gain, reduced liver and epididymal fat mass, and improved serum lipid profiles by lowering triglycerides, total cholesterol, LDL, and free fatty acids without affecting food intake. Gene expression analysis showed that HFD strongly upregulated lipogenic regulators (SREBP 1, FAS, PPARγ) and suppressed CPT1, a key enzyme in fatty acid oxidation. RK reversed these transcriptional disturbances, downregulating lipogenesis and restoring CPT1 expression. Collectively, fermentation enhanced the phytochemical richness of rosemary, and RK exerted protective metabolic effects by suppressing lipid synthesis and promoting fatty acid oxidation. These findings support RK as a promising functional beverage for mitigating diet induced metabolic dysfunction.