Abstract: Water-soluble flavonoids (CBF) were extracted from Coreopsis tinctoria buds using water as the extraction solvent. By combined used of one-factor-at-a-time method and response surface methodology, the optimal extraction conditions that provided the maximum yield of total flavonoids of 145.45 mg/g were determined as follows: extraction time 15 min, temperature 96 ℃ and water-to-material ratio 71:1 (mL/g). The final aim of this study was to investigate the antiaging effect of CBF on D-galactose-induced aging mice and its impact on silent information regulator 1 (SIRT1) and p53 protein expression in the liver of aging mice. The aging mouse model was established by long-term subcutaneous injection of D-galactose (300 mg/(kg·d) for 45 consecutive days, and the mice were also orally administered with either vitamin E (VE, 50 mg/(kg·d)) or CBF at 180 and 700 mg/(kg·d) during this period. The body mass and behavioral state of mice in each group were observed. Hepatic histopathological changes were evaluated by HE staining. The protein expression of SIRT1 and p53 in the liver of aging mice were evaluated by Western blotting. Results showed that CBF had no adverse effects on the growth of mice but significantly improved the bad behavior of aging mice. It alleviated the pathological damage to liver tissues caused by D-galactose, increased the expression of SIRT1 protein (P < 0.05), and inhibited the overexpression of p53 induced by D-galactose (P < 0.05). In conclusion, the water extraction method was applied successfully to extract CBF. It was also demonstrated that CBF possessed promising anti-aging effect, and the mechanism might be related to the activation of the SIRT1/p53 signaling pathway.

Key words: Coreopsis tinctoria buds, water soluble flavonoids, response surface methodology, aging, SIRT1, p53