Abstract:

Objective: To study antioxidant activity of hawthorn (Crataegus pinnatifida Bunge) flavonoid extract (HFE) as well as its growth inhibition effect on Hep-G2 and Caco-2 cells. Methods: Total flavonoid content was determined by NaNO2-Al(NO3) 3 colorimetric method. Antioxidant activity was evaluated by 2,2’-azinobis(3-ethylbenzothiazoline-6-suslfonic acid (ABTS) and 1,1-diphenyl-2-picryl-hydrazyl (DPPH) free radical scavenging assays. Cell growth inhibition effect of HFE was assessed by MTT assay. Results: Flavonoids were dominant in HFE with a content of 98% (calculated on the basis of dry weight). Both ABTS and DPPH scavenging capacities exhibited an increase with increasing HFE concentration. The EC50s of HFE was 88μg/mL and 112μg/mL in ABTS and DPPH assays, respectively; while those of Trolox were 111μg/mL and 118μg/mL. Cell growth of Hep-G2 and Caco-2 cells were remarkably inhibited by HFE in a dose-dependent manner. Whereas, HFE had stronger growth inhibition effect against Hep-G2 cells than against Caco-2 cells. The IC50s of HFE were 115μg/mL and 376μg/mL for Hep-G2 and Caco-2 cells, respectively. Conclusion: HFE has high content of flavonoids, strong antioxidant activity, and strong inhibitory effect against cancer cell growth. Therefore, it has a promising potential as an effective natural antioxidant and an anticancer functional component.

Key words: hawthorn flavonoid extract, antioxidant activity, Hep-G2 cell, Caco-2 cell, growth inhibition