This study was aimed at evaluating the hypouricemic effect of the anthocyanin-rich purple sweet potato extract (APSPE). In vitro, APSPE has been proved to significantly inhibit XO activity in a dose-dependent manner. In vivo, APSPE could not only inhibit the XO activity in mouse liver, but also reduce the serum uric acid level in hyperuricemic mice and affect the expression of mRNA levels of related renal transporters, such as mURAT1, mGLUT9, mOAT1 and mOCTN2. Moreover, APSPE could effectively regulate BUN and Cr levels to normal and decrease the inflammatory cellular influx in the tubule of the hyperuricemic mice. This study indicates the potential clinical utility of APSPE as a safe and effective anti-hyperuricemia bioactive agent or functional food.

The hepatoprotective activity of anthocyanin-rich purple sweet potato extract (APSPE) was demonstrated. Sixty mice were randomly divided into six groups: control group [without carbon tetrachloride (CCl4) or APSPE]; model group (with CCl4 only); positive control group (50 mg/kg body weight silymarin); low-dose group (100 mg/kg body weight APSPE); medium-dose group (200 mg/kg body weight APSPE); and high-dose group (400 mg/kg body weight APSPE). After 10 days intragastric administration of the respective supplements, the mice in all groups except control were injected intraperitoneally with CCl4 (0.15% in arachis oil, 10 mL/kg body weight, intravenous). Twelve hours after CCl4 injection, the mice were measured in terms of liver index, levels of aspartate aminotransferase and alanine aminotransferase in serum, as well as glutathione, superoxide dismutase, and malondialdehyde in liver homogenate. Additionally, the livers of mice were stained with hematoxylin and eosin and sectioned for observation. Nineteen purple sweet potato anthocyanins were identified from the purple sweet potato cultivar Eshu No. 8 and analyzed by liquid chromatography- electrospray ionization-tandem mass spectrometry. Peonidin 3-coumaryl-p-hydroxybenzoyl sophoroside-5-glucoside was first identified in purple sweet potato. The results showed that anthocyanins in Eshu No. 8 had good hepatoprotective activity.