Abstract:This study was aimed at evaluating the antioxidant activities of Prunus cerasifera polyphenols and their protective effects on the livers of obese mice, thereby providing a theoretical basis for the development and utilization of P. cerasifera fruits. First, polyphenols were obtained from P. cerasifera fruits via alcohol extraction. After polyphenol content determination, DPPH, FRAP, and ABTS methods were used to measure the in vitro antioxidant activities of the extracted polyphenols. Next, obese mice models were established and treated with different doses of polyphenols. After eight weeks of treatment, the mice were sacrificed to remove their livers. The liver index was calculated, and the TG, T-CHO, SOD, and MDA concentration in the livers were determined. Moreover, the expression levels of inflammation-related genes were measured via fluorescence quantitative PCR. The results revealed that the total polyphenol, flavonoid, phenolic acid, and flavanol contents in the extracted polyphenols were 439.17, 186.37, 168.27, 68.86 mg/g, respectively. Hence, the total polyphenol content in Prunus cerasifera is relatively high, and the main components are flavonoids. The corresponding DPPH free radical scavenging rate was 97.42%, and the antioxidant activities measured using the FRAP and ABTS methods were 4.36 mmoL/mL and 0.48 mmoL/mL Trolox, respectively, which indicates that the extracted polyphenols had strong in vitro antioxidant activities. Both low and high doses of polyphenols significantly reduced the TG, T-CHO, and MDA contents and enhanced the SOD activity in the livers of obese mice. Furthermore, the polyphenols down regulated the expression of the inflammatory factors interleukin-1 beta, tumor necrosis factor-alpha, and interleukin-6 in the liver tissues. These findings suggest that P. cerasifera polyphenols can improve the antioxidant capacity of the liver, reduce fat accumulation and liver inflammation induced by a high-fat diet, and protect the liver in mice.